EXPERIMENTER PUBLISHING COMPANY, 230 FIFTH AVENUE, NEW YORK Win a Nash Sedan Or $2,750.00 in Cash

EXPERIMENTER PUBLISHING COMPANY, 230 FIFTH AVENUE, NEW YORK www.americanradiohistory.com Win a Nash Sedan or $2,750.00 in Cash

Someone who answers this ad will receive, absolutely free, a fully equipped 7 -Passenger, advanced Six Nash Sedan, or its full value in cash ($2,000.00). We are also giving away a Dodge Sedan, a Brunswick Phonograph and many other valuable prizes-besides Hundreds of Dollars in Cash. This offer is open to anyone living in the U. S. A. outside of Chicago. Solve This Puzzle

There are 7 cars in the circle. By drawing 3 straight lines you can put each one in a space by itself. It may mean winning a prize if you send me your answer right away.,. $750.00 for Promptness In addition to the many valuable prizes and Hundreds of Dollars in Cash, we are also giving a Special Prize of $750.00 in "Cash for Promptness. First prize winner will receive $2,750.00 in cash, or the Nash Sedan and $750.00 in cash. In case of ties duplicate prizes will be awarded each one tying. Solve the puzzle right away and send me your answer together with your name and adress plainly John T. Adams, Mgr., Dept. 3798 written. $4,500.00 in prizes EVERYBODY RE - 323 S. Peoria St., Chicago, Ill. WARDED. - Here is my answen to the puzzle.

My Name John T. Adams, Mgr. Address Dept. 3793 323 So. Peoria St. Chicago, Ill.

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577 Science and Invention for November, 1928

Training Employment FINDING you PREPAIING the better -paid you to fil. a fine position and Drafting job at PLACING you a substantial in it, or money refunded . raise in pay ......

Come into DraRin can read blue -prints and draw plans are "sitting pretty" Men who every building, all these days. No wonder, when you consider that every machine, start on the Drafting table! Intensive production, record -break- industrial activities for expert Draftsmen ing construction operations, have created a great demand capable of designing and calculating original plans. $50 to y$125 a week paid to Expert Draftsmen Drafting isn't just one line of work-it reaches out Get this point-that Automotive into the Electrical, Manufacturing, Building Construction, industries. That is why you'll find well -paid Drafting and Structural vacancies positions advertised in all industrial centers of the U. S. 70,000 12 months. And that is why I advise men to go into reported in the past college Drafting, particularly if handicapped by lack of high-school or you are in competition with high-school and college education. Today to win. graduates for the better -paid jobs. You must have specializedtraining The Entering Wedge to Success A Drafting job GUARANTEED Manufacturing Lines paying 50% more than you earn today in all Building and Drafting, too, because it can be QUICKLY learned at home, in spare time-with- of cost! I recommend sure there -or not a penny out quitting your job, without losing a day's time or a dollar in pay. Because you're on terms of only waiting when you are ready for it. And because the work is so fascinat- Now, at a cost you can afford, will be a good position con- BUY a fine ing and offers better -than-ordinary chances for advancement. For the Draftsman is in close $6 per month, you can actually right in line for promotion to Superintendent increase in tact with important work and BIG MEN. and he is Drafting position and a substantial and other executive positions. pay. A million -dollar institution guarantees both-the training, then the employment. Under money -back penalty. This agreement brings you your SECOND Drafting Lessons CHANCE. To repair a neglected education, to specialize, to change to a line where you can get 'J9auteFREE. and investigate itl 3 ahead more rapidly. Read it, American School to prove you can learn at The spare time! Chartered 30 years as an EDUCATIONAL in- home, in your stitution and like the best resident schools and You will never have a more seri- colleges, conducted NOT FOR PROFIT. We ous personal problem than decid- offer complete, thorough up-to-date instruc- ing your future life-work-so we tion, built by 200 leading Educators, Engi- merely urge you to LOOK INTO neers and Execu- how you like it, see if you learn as unique in- Drafting. See tives. A readily as most men do, get the facts about the op- struction, built to portunities, the salaries paid. the jobs open, the meet the specifica- for promotion. well -paid chances tions of This is why, on receipt jobs as laid down of your name, we will by employers them- send you the first three selves, yet simplified for by lessons of our Drafting ready understanding course without cost or men with- only common obligation. schooling. And we are the first in the home study field to recognize the need of giving a COM- PLETE SERVICE to ambitious men O. C. MILLER, Director Extension Work. -training, plus employment. Which THE AMERICAN SCHOOL, as you are, supplies the D-8594 Drexel O. C. MILLER takes you Dept. Ave. & 58th St., Extension Work equipment you lack, and lands you Chicago, uuuuts Director seek. Without in the better job you Please send without cost or obligation: risk to you! t. Three Drafting Lessons. 2. Facts about the opportunities in Drafting. 3. Your Guarantee to train and place me under money-back penalty.

Name

)iiencaî Address

Occupation Dept. D-8294 Drexel Ave. & 58th St. ,Chicago, Ill. Age W Please say you saw it in SCIENCE and INVENTION

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Formerly ELECTRICAL EXPERIMENTER COMBINED WITH "THE EXPERIMENTER" EDITORIAL, ADVERTISING AND GENERAL OFFICES: 230 Fifth Avenue, New York City NOVEMBER 1928 Published by Experimenter Publishing Company, Inc. H. Gernsback, Pres.: No. 7 S. Gernsback, Vire-Pres. and Treas.; Alfred A. Cohen, Sec'y Publishers of SCIENCE AND INVENTION, RADIO NEWS, RADIO LISTENERS' GUIDE and AMAZING STORIES

Editorial Staff Contributing Editors v) - HUGO GERNSBACK, Editor -in -Chief. Astronomy- Automotive Subjects- H. WINFIELD SECOR, Managing Editor. Dr. Donald H. Menzel, Ph.D., Lich George A. Luers W. Observatory; Radio- A. P. Peck, Herbert T. O'CONOR SLOANE, PIi. J. Luyten, of the Harvard College Observatory. Hayden. D., Entomology and Allied Subjects- Magic and Psychic Phenomena- Associate Dr. Ernest Joseph Dunninger, Joseph F. Rinn, Edward Merlin. Editor Physics- Bade, Ph.D. Foreign Correspondents- JOSEPH H. KRAUS, Field Editor. Dr. Alfred Dr. Harold F. Richards. Ph.D., Ernest K. Chapin, Gradenwitz, Germany; Dr. H. Becher. PAUL WELKER, Radio Editor. M.A., Dr. Donald H. Menzel, Ph.D. Germany; C. A. Oldroyd, England; S. Leonard Bas - tin, England; Count A. S. GERNSBACK. Wrinkles Editor. Chemistry- N. Mlrzaoff, France; Ilubert Raymond Slouka, Czecho-Slovakia; P. C. van Petegem, Bol - B. Wailes, Dr. Ernest Bade, Ph.D. land; Richard Neumann, Austria. IN DECEMBER ISSUE CONTENTS Pump Invention Makes OF THIS NUMBER a Fortune GENERAL SCIENCE CHEMISTRY Editorial 585 By Hugo Gernsback Experimental Chemistry and Electrics The absorbing human -interest Edited 610 story of a pump inventor Moving Scaffold Aids Masons 586 by T. O'Conor Sloane, Ph.D. who Television Directs Two Orchestras Food Adulteration 611 587 By William had a radically new idea that A Motor Bus Sleeper 588 Lemkin, Ph.D. brought him fame and fortune. The Month's Scientific News Illustrated 589 The story of a successful in- By George Wall HOME MOVIES How Lindbergh's Famous Engine was Manu- ventor that you cannot afford Home Movies-Monthly Department 608 factured 590 Conducted by Boo to miss. By H. W. Sccor Bennett How to Save Coal 592 TELEVISION City of the Future By C. D. Kee/y, Mechanical Engineer What will the large Entertaining with Ilypnosis 593 Popular Television-A New Monthly Feature 618 city of By Rena Murar Stereoscopic to -morrow look like? Will we Television Sciencé Probes Spider's Secrets 594 Radio Movies 622 have skyscrapers or under- By Uthai Vincent Wilcox ground apartment houses ? Read Inventors Ease Mothers' Cares 596 RADIO By Rhys G. 77tackwell the opinion of eminent engineers Plane Broadcasts Radio Photo Movie Tricks 598 New 624 and architects. Illustrated By Joseph Radio Devices 625 with H. Kraus Mid -Ocean Radiophone attractive pictures. Is Civilized Man Losing His Sense of Smell.? 600 626 By Walter Raleigh Radio Oracle 627 Money! Danger-High Vacuum 601 An interesting and popularly By Emery G. Gregory AUTOMOTIVE Scientific Progress 602 Motor Hints written article showing the sci- Peak Load 605 Conducted 604 By E. G. -Martin by G. A. Leers ence behind the making and dis- A Motor Bus Sleeper Magic-A Monthly Feature 606 588 tribution of Uncle Sam's legal By Duuningcr tender. Scientific Questions 607 HOW -TO -MAKE -IT Jupiter in a Stereoscope 607 Building Television Constructor By Donald H. Menzel, a Speed Boat 612 Ph.D., Lick Observatory \\'ood Turning for the Amateur-No. All the latest information with Readers Forum 617 5 of a Series 614 clear drawings will be presented Scientific Humor 628 By H. L. Weatherby Latest Patents 629 How -To -Make -It for the benefit of the television The Oracle 630 Wrinkles, 615 Patent Advice Recipes and Formulas 616 receiving set constructor. 640 Edited by S. Gernsback

HOW TO SUBSCRIBE FOR "SCIENCE AND INVENTION." Send your name, address and remittance and money orders should be made payable to Experimenter to Experimenter Publishing Co., 230 Fifth Ave., New York City. Checks Publishing Co., Inc. Mention magazine desired, publish RADIO NEWS, AMAZING STORIES and RADIO LISTENERS' GUIDE. Subscriptions may inasmuch as we also rates. be made in combination with the other tions just mentioned at special reduced club Send postal for club rate card. Subscriptions start with the publica- ON EXPIRATION of your subscription we enclose a renewal blank in our current issue unless otherwise ordered, last number to you. and notify you by mail. Then, unless we receive your order and remittance of a renewal, delivery of the magazine is stopped. SCIENCE AND INVENTION is published on the 10th of each month. There are 12 numbers per year. Sub- scription price is $2.50 a year Sn U. S. and possessions. Canada and foreign countries, U. S. coin as well as U. 8. stamps accepted (no 03.00 a year. foreign coin or stamps). Single copies, 25e each. All communications and contributions to this journal should be addressed to Editor, SCIENCE TION, 230 Fifth Ave., New York City, N. Y. AND INVEN- Unaccepted contributions cannot be returned unless full postage has been included. ALL accepted contributions are paid for on publication. AND INVENTION Monthly. Entered as second-class SCIENCE matter May 10, 1924, at the Post Office at New York, N. Y., under the act of March 3, 1879. Additional entry at Dunellen, Francisco, Calif. Title Registered N. J. and San at the Patent Office. Copyright, 1928, by E. P. Co., New York. The Contents of this Magazine are copyrighted and must Inc., giving full not be reproduced without credit to the publication. SCIENCE AND INVENTION is for sale at all newsstands in the United States and Canada. European Agents, S. J. Wise Et Antwerp, Belgium. Cie, 40, Place Verte, ADVERTISING REPRESENTATIVES New York Office: Chicago Office: Rhodes & Leisenring, Rhodes & Leisenring, 624 Graybar Building 307 North Michigan Avenue

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www.americanradiohistory.com Science and Invention for November, 1928 579

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Lots of people know how to make a dry cell but not the Eveready Columbia PROBABLY you know how to make a dry cell. No secret about it. The principal ingredients EVEREADY are zinc, sal ammoniac, manganese, carbon. With just those four things you could make a COLUMBIA dry cell that would work-for a time. But we Dry Batteries add tiny quantities of other things, too, mea- -they last longer sure them with great exactness, add them just so, control every process by laboratory tests, and turn out a product that is scientifically exact. Some of the ingredients we mine in our own mines, refine in our own mills, and thus govern quality completely. There's no secret about the Eveready Columbia except this: We know how to make it. Thirty-three years of scientific investigation and controlled manufacture have developed it until today it is the greatest dry cell made. Available in single cells, and in batteries of 4, 5 and 6 cells, 6, 7i/ and 9 volts, ready -connected in a water- FOR RADIO: Insist on the No. 7111 proof steel case and sold as the Eveready dry cell, six inches of battery good- Columbia Hot Shot. ness, scientifically designed to give its best results on radio sets using NATIONAL CARBON COMPANY, INC. tubes of the WD -11 and WX-11, and New York San Francisco UV -199 and UX-199 types. Unit of Union Carbide and Carbon Corporation

Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com Science and Invcni ion for November, 1923 INDEX TO ADVERTISERS II

PAGE PAGE PAGE PAGE A Douglas, Lyle 664 Le Page's Craft League 639 Piccadilly, The 665 Dryer, Adams, John T., Prof. J. A. 645 Liederman, Earle E. 669 Pines Chemical 'Co. 636 Inside Front Cover Lindstrom E & Co. 658 Plymouth Rock Squab Co 642 Allied Radio Corporation, Long -Eakins Co. 658 Polachek, 644-659-665-669 Electro Thermal Co., The 653 Z. H. 640 Polk & Company, R. American Detective System 661 Evans & Co., Victor J 643 L 664 Mc Popular Chemistry American Radio & Merc. Co. 669 F Co. 658 McCarrie School of Me- Popular Book Corp. 635 Fawcett Publications, Inc 633 chanical Dentistry 652 American School, The Porter Chemical Co. 660 Federal Mail Order McGraw-Hill Book Co 637 577-664 Corp 657 Practical Drafting Institute American School of Avia- First Hawaiian Conserva- of America 649 tion 665 tory of Music 669 M Press Guild Inc. 663 American School of Music Fisher Mfg. Co., Adam 640 645 Mann & Benton 645 Publishers' Classified Serv- American Franklin Institute ice School of Pho- 653-660 Meccano Co., Inc...... , 660 655 tography 647 Franklin Publishing Co 664 Metal Arts Co. 638 R American Telegraph & Free Thought Press Ass'n, Telephone Co. Metal Cast Products Co.....660 645 The 631 Radio Association of Midwest Anita Institute 642 Radio Corp'n America 642 G Back Cover Audel & Co., Theo., Radio Inst. of America 667 Miller, Inside Back Gernsback, S. 666 Carl 642 Cover Radio Specialty Co. 668 Miller, Monroe, E. Automatic Rubber Co 668 Gilson Slide Rule Co. 668 642 Ralston University Press 583 Miniature Aviation Institute of U Ship Models, H Inc. Randolph & Co. 640 S. A. 663 669 High School Home Study Movie Operators' School 653 Renuzit System, The 657 Bureau 659 Roat & B Munn & Company 640 Lohman 657 Hobart Bros. 644 Barawik Co. 662 Ross -Gould Co. 662 Hoenack, Paul 642 N Blancke Auto Devices Co 638 Royal Novelty Co. 664 Hotel McAlpin 661 Bliss Electrical School 657 National Carbon Company, Royal Sales Co. 654 Hotel Manger 632 Inc. 579 Breakers, The 659 National Electrical School 632 S Brief English Systems, Inc 657 I National Radio Institute 581 School of Engineering Buescher Band Instrument Ideal Aeroplane & Supply of Milwaukee 667 Co. 638 Co., Inc. 668 National School of Watch- making 657 Setbuilders Supply Bureau of Inventive Sci- Illinois College of Photog- Co. 660 ence 642 raphy 644 New Method Mfg. Co. 645 Smith Typewriter Sales Corp. 648 Burns School of Wrestling 669 Independent Electric Wks 664 New York Academy of Music 632 South American Inkograph Co., Inc. 659 Service C New York Bureau 664 International Correspond- Electrical School 647 South Bend Lathe Works 669 Campbell Co., The Wm 638 ence Schools .636-648-654-668 New York Institute of Sterling Diamond & Watch Chemical Institute of N International Typewriter Photography 651 Co., Inc. Y., Inc. 582 Exchange 638 661 Northwestern Chicago Correspondence School of Strongfort Institute 634 J Taxidermy 632 School of Music 652 Jenkins Corporation 636-647-650 Norton Institute Clarke Sanding Machine 648 T Co. 662 K Tamblyn, F. W 632 O Coleman, Watson E. 642 Karas Electric Co. 638-660 Tarbell System, Inc. 584 O'Brien, Clarence A. 641 Consrad Co., Inc., The, Kelsey Co., The 653 Townsend Laboratories 658 648-654-662 Treasure Sales Co. 650 Cox, S. J. 647 L P Laboratory Materials Coyne Electrical School 661 Co 642 Parks Woodworking Ma- U Lacey & Lacey chine Co., The 642 664 Underground Aerial Sys- D Lancaster & Allwine 642 Pathfinder Publishing Co 647 tems 649 Deagan, Inc., J. C 660 Landon School, The 652 Perfect Penmanship Inst 659 W Detroit School of Letter- La Salle Extension Uni- Petroleum Engineering ing 632 versity 650 University 665 Waco Tool Works, Inc..... 651

www.americanradiohistory.com 581, Science and Invr'ntion for November, 1928

x,350 a month X500 a month '450 a month addition to my regular work in "When 1 enrolled with the N. R. I., I "In "I feel proud of my success in Radio and best was a motorman on a trolley car. Now what I believe to be the largest to date. My profit during the last two the Southwest, I have a fine, fast-growing Radio busi- equipped Radio Shop in months amounts to $700. I am making KGFI. I am proud finished my ness. When only half way through the I am now operating good and I have not fact I installed and put grateful for course started bringing in extra money. of the that N. R. I. course yet. I am KGFI on the air without help of any- and co-operation to date I made $420 in my spare time. Now I your training about one except the N. R. I. I am averaging and look forward to still bigger success have a bank account of $2800 and all come $450 per month." when I gradaate." $300 worth of stock. It has M. Jones, less than Frank Clarence Heffelfinger, from Radio since graduating 922 Guadalupe St., San Angelo, Tex. Temple, Penna. six months ago. I cannot begin to express my thanks to you and all those connected with N. R. I. for what you have done for me." Richa-d Butler, 3535 Sheffield St., Philadelphia, Pa. gq- ei !_=- READ what BMoney my m en make in RADIO $350, $450, $500 a month. That's making real money. I GIVE YOU THE RADIO I Will Train What business other than Radio offers such oppor- FOR A tunities after sit to twelve months training? None PARTS that I know of. More proof-last year electricians, HOME EXPERIMENTAL You ceHome farmers, mechanics, clerks, railroad men, book- LABORATORY keepers, preachers, doctors, and men from 78 other In Your trades and professions enrolled with me 'o prepare for the Radio field. Spare Time Big Growth Making Many Big Jobs NO NEED to leave home. job, give me you will say, to make Hold your business, to one hour a day AWÒNDERFUL give them up for one-half men trained for other fields, spare time. In six to twelve months you their eyes wide open. They of your Radio. Yes, but they had can be a trained Radio Expert, ready to step into and I big growth makes know what you know-that a new job with a real future. big jobs and many opportunities to earn big money. Heffelfinger, Jones, and Butler couldn't make any- $10 to $30 a Week While Learning thing like this money before, although they probably of my students make $10, $20, $30 a worked just as hard-maybe harder. Trained men MANYweek extra while learning. I teach you to are needed for the big jobs the amazing growth of begin making money shortly after you enroll. Radio is creating. G. \V. Page, 1807 21st St., Nashville, Tenn., Made $935 in his spare time. Salaries Up To $250 a Week Money Back If Not Satisfied go along at $25, $30, $35 a week when the KNOW the kind of training you need. I have WHYgood Radio jobs pay $50 to $250 a week? Cut put hundreds of men and young men ahead. loose from drudgery, small pay, no-future jobs. Get I am so sure that I can satisfy you too that I will into a live -wire field that offers you a real chance. agree to refund your money if you are not satis- You don't neec a high school or college education to fied when you complete my course. become a Radio Expert. Many of my most successful Find Out What Radio Offers You graduates didn't finish the grades. MY 64 -page book explaining where the big jobs are Practical Experience With Course and what you can make is you six big" outfits of Radio parts. With FREE. Mail coupon. IGIVEthem you can build and experiment with one hun- No obligation. dred different circuits-learn the "how" and "why" Address: Dept.33T of practically every type of set made. This. makes J. E. Smith, Pres., learning easy, interesting, fascinating, your training Nat'l Radio Institute, complete. Nothing else equals my method. Washington, D. C. TELEVISION also Included WITH THEM YOU knowledge of Radio will be right up to the CAN BUILD IOO YOURminute with Radio's progress and inventions when Send this Coupon you take my training. Television, the new field for CIRCUITS. 4 YOU Radio experts, is included. Not one system for BUILD ARE SHOWN J. E. Smith, sending and receiving pictures by Radio, but all of Dept..13¡ National Radio Institute, them-Jenkin's, Cooley's, Bell's, Baird's, Belin's, HERE. MY BOOK Washington, D. C. Dear Mr. Smith:-Send me your book. I want to know about Alexanderson's. EXPLAINS THIS method of teach- Television can easily and quickly become as large the opportunities in Radio and your practical PRACTICAL FASCIN- ing at home with six big outfits of Radio parts.. This request as the whole Radio industry is today Broadcasting does not obligate me to enroll stations will soon need trained men, so will manufac- ATING WAY OF turers for the designing and building of sending and LEARNING RADIO Name l,e receiving sets. It won't wait for you. Get ready quick. Address

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www.americanradiohistory.com 582 Science and Invention for November, 1928 Cl/em/s try to Suce.çs Some people measure success in terms of money and others in degree of knowledge and culture. Chemistry is the one uncrowded profession today Wili Fi,. that offers both. America, always a land of amazing opportunities, is especially so now in the field of applied Chemistry. In- dustries have developed within eight years t` a more rapidly than the output of trained men to conduct them. Every big industry needs chemists and there is a real demand for them immediately. Earn a 'Bigger Salary from now on Good Chemists Command High Salaries Not only are therejboundless opportunities for ;unas.siiig Chemistry, wealth in but the profession affords congenial employment at good salaries to hundreds of thousands who merely follow out its present applications. These applications are innumerable, touching intimately every business and every product in the Just a Few Letters world. The work of the chemist From Students Who Have can hardly be called work at all. It is the keenest and most kind of enjoyable Taken This Course pleasure. The clays in a chemical laboratory are filled with thrilling and delightful You will probably be pleased to experimentation, with the alluring prospect of a learn one of the lessons gave me discovery that may spell Fortune always at hand to an Idea to turn my chemical spur your enthusiasm. knowledge to profitable account. I am now making a varnish and You paint which undersells the other can make yourself independent for life by unearthing type products by $2.60 a gallon. in some cases more. lIave been receiving gallon orders from paint- one of Chemistry's undiscovered secrets ers during past week which has netted me a profit of $12.50 for Do you remember how my "spare -time chemical indus- the tales of pirate gold used to fire your imagina- try." Many thanks for your tion and make you want to sail the uncharted seas in training thus far. search of treasure and J. J. KELLY. adventure? And then you would regret that such things were no longer clone. But that is a I am but half -way through your mistake. They are done-today and every day-not.on course and am certain that I have desert islands, but in the chemical laboratories throughout your saved my Company many times try. Quietly, own coun- the cost of the course and raised systematically, the chemist works. His work is difficult, but myself in the shareholders' estima- more adventurous than the blood-curdling tion. The knowledge obtained has deeds of the Spanish Main. In- its Immediate practical application T. O'CONNOR SLOANE, stead of meeting an early and violent death on some forgotten shore, he and I do not hesitate in saying A.B.,A. M.,LL.D.,Ph. D. gathers wealth and honor through his valuable contributions your course and the personal at- Alfred to humanity. tention you give is invaluable to Nobel, the Swedish chemist who invented dynamite, made so many -'millions that the practical man in any business the income alone from his bequests provides five 340,000 prizes every where chemistry plays a part. You Noted Inst ructor, Lectur- ment of year for the advance- may use science and peace. Herman Frisch, who showed how to extract sulphur, built this letter and my name er and Author. Form- up a huge fortune. C. M. Hall, the chemist who discovered how to and address to the furtherance of made millions through this discovery. manufacture aluminum, your good work. erly Treasurer Ameri- F. G. Cottrell, who devised a valuable process for JOHN WALTER. recovering the waste from flue gases, James Caylev who showed how can Chemical Society losses in steel manufacture, l,. to save enormous I have not written since I re- H. Baekeland, who invented Bakelite-these are only a ceived the big set. I can still say and a practical chemist few of the men to whom fortunes have ruine through their chemical achievements. that it far exceeded my anticipa- with many tions. Since I have been studying well-known YOU CAN LEARN AT HOME with your school I have been ap- achievements to his To qualify for this remarkable pointed chemist for the Scranton credit. calling requires specialized training,' Formerly it was Coal Co., testing all the coal and Not only has necessary to attend a university for several years to acquire that ash by proximate analysis. The Dr. Sloane taught to our highly perfected training, but thanks lessons are helping chem- and thorough system of instruction, you can now stay at home, me wonder- istry for years keep your position, and let us educate you in Chemistry during your fully, and the interesting way in but he with only spare time. Even which they are written makes me was for many common schooling you can take our course and equip yourself for immediate wait patiently for each lesson. years en- practical work in a chemical laboratory. MORf..4IS C'OI"Lt:NS. gaged in commercial EASY MONTHLY PAYMENTS chemistry work. You don't have to have even the small price of the -course to start. You can pay for EXPERIMENTAL EQUIPMENT it in small monthly amounts-so small that you won't feel them. The FURNISHED is very low, and includes cost of the course TO EVERY everything, even the chemistry outfit-there are no extras to STUDENT buy with our course. Our plan of monthly payments places a chemical We give to every student, without the reach of everyone. education within additional charge, his chemical equipment, including fifty-two pieces of laboratory apparatus and supplies, and fifty-two different chemicals and reagents. These MAIL THE COUPON FOR FREE BOOK comprise the apparatus and chemicals used for the experimental work of the course. The fitted heavy Your name and a,Ii '-. on the coupon will bring you by return mail our interesting wooden box serves not only book, "OPPORTU SI VIES FOR CIHEtiIS'l'S," free as a case for the outfit, but also as a useful laboratory accessory and full particulars about the course for performing countless experiments. and what it will do for you. You owe it to yourself to get this book. Send the coupon right now while it is fresh in your mind. Or just write your name and address on a postal and mail to us. But whatever you do, act today. CHEMICAL INSTITUTE OF NEW YORK, INC. Home Extension SEIZE THIS OPPORTUNITY-MAIL COUPON Division ll NOW ! 16 -18 -D -East 30th Street, New York, N. Y. l'lease send the at once, without any obligation on my part, your free book, "Opportunities for Chemists," and full Chemical Institute of New York, Inc. particulars about the Experimental Equipment given every student. Also please to Home Extension_Division' tell meabout your plan of payment. 11 NAME 16 -18 -D -East 30th Street New York, N. Y. ADDRESS CITY STATE S -f-11-28 Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com Stielire and Invention or November, 1928 583

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www.americanradiohistory.com Science and Invention for N ovember, 192S

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www.americanradiohistory.com Volume XVI Selellet November, 1928 Whole No. 187 No. 7 P

HUGO GERNSBACK, Editor -in -Chief H. WINFIELD SECOR, Managing Editor DR. T. O'CONOR SLOANE, PH.D., Associate Editor Editorial and General Offices - - - 230 Fifth Avenue, New York

"Those Who Refuse to Go Beyond Fact Rarely Get as Far as Fact" - HUXLEY

MAKE MONEY FROM SCIENCC

By HUGO GERNSBACK

THE most amazing and often incomprehensible fact about its really incalculable wotth to the inventor and manufacturer. science is that comparatively few people make use of scien- There is a tremendous market in this country for new labor-saving tific progress. The reason for this statement is that while devices pertaining to the household. Not all of those sold at present science and the art of invention keeps increasing by leaps are patented. Yet, they enjoy huge sales. and bounds, the very multiplicity of subjects makes it almost impos- For many decades, straw hats were made in the old manner, but sible for the average man to keep abreast of this progress. recently, someone came along and started to spray straw hats with Anyone familiar with patent matters often finds out that an a sort of varnish, when to and behold, we have a waterproof straw apparently new idea in one line of endeavor, has been used for many hat. Here is an exceptionally simple idea that anyone could have years in another totally different field. Here is an actual occurrence thought of and profited by. And if it can be done with straw to illustrate this: Years ago, a safety -razor blade manufacturer hats, why not other objects. The list would seem to be endless. spent a great deal of time to invent and patent an automatic process Another similar idea affording protection from the rain was in order to wrap safety blades. After a great deal of money had recently offered in New York. This was nothing less than a com- been expended, it was found that such a machine was already in plete raincoat and hat for twenty-five cents. Impossible as this existence and was used to wrap no less a thing than chewing gum! sounds, the entire outfit offered only for emergency purposes at So :today, practically the identical machinery used to wrap chewing theater entrances, is a small package, neatly folded in an envelope. gum is used to wrap razor blades. When unfolded, we have a wax paper raincoat and hat, which can A manufacturer of condensers for radio purposes expended a be worn a few times and then discarded. A simple idea that any- young fortune trying to evolve a machine to automatically wind one could have thought of and made money from. The idea, paper interleafed with tinfoil for his condensers, only to find after- as far as we could ascertain, was not even patented. wards that an identical machine was used for many years to wind In talking about waterproofing, they are now making ladies hose silk ribbon between paper, as is sold in most notion waterproof by means of a special process. It should stores. The list is endless, and it illustrates the old prove a good seller. Somebody could reap a fortune statement that "One half of the world does not know by getting up a formula to varnish or impregnate what the other half of the world is doing." newspaper as it comes off the printing press. While While a patent is an excellent thing, and while NEW!!! not so important for newspapers, it is of great veritable fortunes have been made from patents, it TELEVISION importance to magazine publishers who publish maga- is not always a patented idea that makes money. While DEPARTMENT zines on ordinary newsprint stock. This paper, as a patent should always be secured in order to safe- THIS a rule, does not last more than a few years; after guard a new invention, yet there are many processes IN that it falls to pieces. If some cheap varnishing and many devices that can be used by anyone with- NUMBER arrangement could be devised to attach to a press, out owning a patent. It also happens frequently that SEE PAGE 618 after the magazine is printed, and as it comes off many patented inventions are ahead of progress and the press, a large fortune could be made if the that the inventor does not always reap the benefit. process was simple and cheap enough, as most pub- The important art of television is a good example lishers would then avail themselves of the idea. of this. The Nípkow disc, which is now used in all If someone has a great deal of time on his hands, television transmitters and receivers, was invented in 1884, and nothing would pay better than to make a comprehensive catalog of even if it had been patented at that time, the patent would long all the waste -products in this country, and then try and com- have expired by this time, without benefitting the inventor, simply mercialize them. Years ago, gas plants threw away all of their because the art had not progressed sufficiently. coal tar. This, today, is the most valuable product and often more From the foregoing it will be seen that no matter what" business valuable than the main product, that is, the gas. you are engaged in, with few exceptions, it pays to know what is But what about the exhaust of our automobile? There is a good going on in other branches of industry, because frequently, as I deal of combustion going on that might be saved and turned to some have demonstrated, one line of progress or one idea or one patent profit. Sawdust used to be thrown away, or given away free. that may have expired, can be used in another line to good advantage, Today, every lumber mill and every woodworking plant sells this and steal a march on one's competitor. former waste -product at a good profit, because it is used for many This, of course, is not always apparent, and like all ideas, it purposes, such as artificial wood and processed wood objects. must be tried out and no one knows in advance what may happen. Years ago, the sauerkraut industry threw away their by-product, It would seem, that to the average business man, particularly those which was the juice or liquid, and for which, no one could find a who manufacture any commodities, knowledge of scientific progress, use. At the present time it is bottled and sold as sauerkraut cock- inventions, and patents should he a most important consideration. tail, which is a wonderful intestinal stimulant and is growing in Yet, strange to say, very few business men ever avail themselves poptdarity by leaps and bounds. It begins to look as if sauerkraut of such information. Of course, not every foreign idea can he juice will become more valuable than its parent. used in every business, but I dare say, that there is not a single Every family throws away tons of loose newspapers and maga- business than cannot profitably use any number of ideas from other zines every year. It is true, that a large percentage of this finds arts and other Tines of industrial endeavor. its way to the paper mills, there to be used over again. But it The constant reading of all popular scientific literature and the seems that there should be other and more important uses for news constant perusa`. of the weekly Patent Gazette issued by the Patent and magazine paper after it has served its purpose. Office in Washington will prove wonderfully valuable to practically The list of such waste-products and waste articles is endless. any business. Its subscription price is insignificant-compared with Fortunes are in store for those who solve these problems.

Mr. Hugo Gernsback speaks every Tuesday at 9.30 P. M. from Stations WRNY (326 meters) and 2XAL (30.91 meters) on various scientific subjects. 525

www.americanradiohistory.com 586 Science and Invention for November, 1928, Moving Scaffolds Aid Masons Stone and Brick Work Placed on Skyscrapers in Record Time; Masons Follow Iron -Workers

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MIR - ' _-L ' TS-.- !,!,y S _ate -¿?.T.S J ..... - . HOW SCAFFOLD /5 SOMETIMES CURVED AS ONE SECTION OF WALL /S F/N/SHED FASTER "THAN ANOTHER ANI

The above illustration shows how the scaffolds can be -SEAM STRUTS curved as one section of the building is finished faster than another. The drawing at the 'RON 1 -BEAM right shows how the YOKE platforms are BOLT moved by means of SHACKLE ha^-d winches. CRBLE The scaffolds are placed entirely around the walls of STEEL the building, and CABLES are cleverly joined to each corner The illustration at the PLANK WIRE OR CANVAS left shows these ROO, S'O PROTECT MASONS moving platforms being used in the GUARO FENCE construction of a CABLE RATCHET large skyscraper. A TAKE-UP DRUMS roof Is provided to protect the workers. /RON FRAME 2^ PLANKS Iour present-day Machine Age, engi- or ten floors to be finis ied without changing neering and architectural development is the position of the cables. When the stone- of a skyscraper, is the placement of the rapidly advancing. In all big cities sky- work has been put on the maximum number construction elevators which lift the bricks scrapers are springing up like veritable of floors, the cables are removed and placed and materials, which cannot be carried from mushrooms. As each day passes, new con- higher up on the building. the street level. These elevators are built struction methods are invented to keep in Another interesting point in the erection just as soon as a steel skeleton has been step with the modern building design. Re- started, and keep pace with the growth of cently, moving safety scaffolds have been the structure. The heavy elevator motors, put to use in the erection of the large build- water tanks, and other materials, are raised ings and have greatly aided the masons in to the upper floors of the building by a steel applying the stonework. The new scaf- boom derrick before the masonry is put on. folds are made of planks supported by an The contraction and expansion in the iron frame and are roofed over with boards, outer masonry walls of the building is taken wire or canvas to protect the workmen care of in two ways. The brick or stone from objects falling from above. A heavy wall is divided up into a number of sections wire frame around the edge of the scaffold by the steel skeleton construction. Besides assures protection to the pedestrian and this, flexible cement is used at each floor safety for the workmen. To further insure line where the floor girders join the uprights. Before the masonry is put in place, The illustration at the right shows how the tar paper and tar are used to waterproof the steel skeleton of a building is filled in with steel work and prevent water from reach- the stonework at any desired floor. With the ing it and becoming pocketed. It is inter- old type of masonry construction, where the walls supported the weight above them, this esting to note that any section of the outer would be impossible, and the masonry would brick or stonework can be removed with- have to begin from the bottom. out causing a collapse of the building.. This is macle possible by the steel construction of the pedestrian's safety, the sidewalks are our modern buildings. Forty years ago the roof ecl over. floors above the street level were sup- The scaffolds are suspended with steel ported by brick or stone walls and towers. cables from I-beam struts from a portion In the older buildings, which had from ten of the building framework. A series of to twelve stories, the huge supporting walls winches placed at the front and back edges took up an enormous amount of space on of the mason's platform permits it to be the lower floors. The present-day steel skele- raised or lowered by the workmen. As one ton supports the whole weight of a sky- portion of the wall is finished, the scaffold scraper. and the stone or brick masonry it, not bear any part is raised by simply operat;ag the lever on simply covers but does Sometimes one portion of of the weight. The illustration at the bot- the hand winch. this and illus- the wall is finished faster than another. tom of the page will show This condition is illustrated here, and it trates how the masonry work is frequently seen that the scaffold can he bent put in place on the upper stories before it is will be lower floors. Detailed in- or curved at will. On one large building applied to the which the editors watched from the win- formation on modern skyscraper erection dow, the scaffolds assumed a double curve will he found in an article entitled, "Why is frequently during the construction. The a Skyscraper?" by H. W. Secor, in the moving platform or scaffold permits eight August, 1928 issue of this magazine.

www.americanradiohistory.com Science and Invention for November, 192

".à ,1.6.'41,L FRITZ REINER, the conauctor of the Cincinnati Symphony Or- chestra, plans to put television into practical use in the conducting of two orchestras. The latest invention will be employed in the playing of Mahle 's Symphony No. 2, where, in the last movement, a full orchestra and a small orchestra are needed for the groper rendition of the selection. The score requires that the sound of the small orchestra shall reach the listener but faintly. Here- tofore, an assistant director, stationed behind the stage, conducted the second orchestra as he watched Mr. Reiner through a hole in the wall. It is planned to have his picture, time and placement, thrown on the scream in the room where the second orchestra will be stationed, thus enabling it to keep exact time with the main body of musicians. Furthermore, the tones of the hidden orchestra will assume a remarkable reali_y of faintness and distance.

e SUPPLY P' ALL LARGE Oi:eCi-IESTFA SYMPHONY IN CLOSED L- ORC±,.IEv,._k-eFa ROOM The above drawing shows how a hidden orchestra will be kept in time with The leader of the orchestra will be televised and bis picture thrown upon a the main symphony orchestra by means of television. The conductor's screen, keeping both bands of musicians in the same tempo. This is to be movements will be thrown upon a screen in front of the hidden orchestra. put into effect during a concert given by the Cincinnati Symphony Orchestra.

www.americanradiohistory.com 588 Science and Invention for November, 1:-_'

PORT HOLE UPPER COMPARTMENT WASH BASIN AND IN VENTILATORS SEATS IN POSITION THERMOS JUG EACH FOR DAY TRAVEL COMPARTMENT A MOTOR BUS LAVATORY CHEF STEWARD EXTRA SEAT IN DRESSING SPACE DRIVER OBSERVATION SEATS SLEEPER REMOVABLE Now Possible to Travel Across MOTOR United States at last on Buses Carrying Sleeper Berths and French

REAR EXIT Chefs

AISLE IN CENTER PORT HOLE OF CAR SERVING VENTILATOR ALL 13 COMPARTMENTS KITCHEN COMPARTMENT SHOWING UPPER AND LOWER BERTH DOOR WHEN OPEN FOR NIGHT TRAVEL SEPARATES KITCHEN FROM ENTRANCE WAY MAIN ENTRANCE THE ultimate idea in motor bus construction has been reached with the introduction of a night coach, which provides sleeping quarters for twenty-six passengers. The compartments are arranged in upper and lower decks, and each accom- modates two people. At night the cushions of the seats are used to form the berths. The bus is 34 ft. 6' in. long, 8 ft. wide, and 10 ft. 3 in. high. It weighs 14,000 lbs. and was built at a cost of $30,000. A remarkable new feature of the bus lies in The coach is constructed entirely of metal and has the fact that the motor can easily be reno chassis. A heavy moved for repair, as shown above. frame of steel around the car just below the lower berth windows serves as a chassis. Photos courtesy Pickwick Stages System.

The photographs at the left show the passenger seats in normal use and when the berths are made up. At the right is a photo of the new motor stage. The illustration at the top of the page shows the internal construction and how greatest comfort is provided in a minimum of space by clever engineering design.

Seattle --_-_rN. WR ---7 MINN.

Duluth Yellowstone Natl. Park St Peel Idaho Falls wYO Sheridan Minneapolis'V Milwaukee

Dubuque

Kansas City Eldorado

Santa Barbara Us Angele' (Worn ' Cig San Diego Hot Springs Ft Wort ,.Tucson Dallas

Houston' The above map shows the various trans- New Orleans continental bus routes; the buses here shown operate over a great part of this system. Galveston The buses shown here operate on two routes between the east and west. Terminals are located in all the principal cities.

www.americanradiohistory.com Science and Invention for November, 1928 589 The Month's Scientific News Illustrated By GEORGE WALL

Two buildings in Washington, :L ñAR D. C. were burned to the ground in IPPORi$ order to obtain scientific data. The ti unusual fire was part of a series of AiR tests being made by the Bureau of VENT Standards in order to obtain accurate information of fire prevention. Observations were taken from a dug- out in a boiler room nearby, and by means of thermo-couples the temperatures were measured. Estimated temperatures of 3,500 degrees Fahrenheit were obtained. Thirty-five safes in ED different parts of the building, numbered for identification, held thermom- eters and useless records so as to determine the degree of protection afforded.

Recently, at Tracy, California, an ai, - plane was brought to earth with a huge parachute, as illustrated above. Only slight damage was done to the plane, Jean A. Lussier recently went over the Horseshoe Falls which was at Niagara Falls In a huge rubber ball. He is the third allowed to fall from a height man in history o of 2,000 feet. The pilot released a small to accomplish this death -defying feat. parachute, which in turn unfolded a The ball was of special design and was made according larger one. Failure of the smaller para- to his own design and weighed seven hundred pounds. Lussier chute to open quickly nearly ruined the started his trip three miles up the river and traveled that dis- experiment. The plane began to spin tance, including the drop of the falls, in 50 minutes. When the and the pilot was prepared to leave it, ball was reached after the trip, it was right side up, and only a when the ropes untangled. few minutes time was required to open it, because of the specially constructed lid. The passenger suffered only minor bruises in his perilous journey and all were received in the terrific bouncing which was experienced while going over the rapids. The above illustration shows the construction of the ball which was fitted with a ballast and an air vent.

Motion picture films can now be retouched much the same as portrait negatives are at the present time. A French patent makes provision for retouching movie films by looking at the projected image and the image of the retouching pencil. In this manner many small 'MOVIE details can be treated. The appa- CAM EP55 ratus is the invention of L. H. LOCATE Burel and H. Debain.

Ca/1 FitM RFLECT t' cwru SCREEN AS IN POST CANO PROJECTORS AMP

For the first time in aviation history an army dirigible successfully landed mail on the roof of a speeding train. Army officers maneuvered a 200 -ft. non -rigid ship down on top of a mail car roof after a chase of thirty-five miles. In spite of the speed of the train, the dirigible maintained its position long enough to permit the transfer of a sack of mail, and to demonstrate the possibility of air -to - land transfer. Cameras were carried in both dirigibles and moving pictures were taken while the stunt was carried out. During the chase the dirigible traveled at a high rate of speed directly above the train tracks. On one side of the tracks were strung telephone wires, while on the other, ran high tension power lines. The airship traveled between these electric walls and almost came to grief when one of the trailing cables swept a hi tension line. In spite of the air currents set up by the train, the dirigible finally managed to catch the train and drift above it.

www.americanradiohistory.com for November, 1928 590 Science and Invention How Lindbergh's Famous A Trip Through the Manufacturing Plant Where By H. W.

all gears and the valve rocker forging is that of cutting the threads on the THE writer recently had the pleasure crankshaft, later, and being conducted arms. upper end of the cylinder onto which, of visiting the cast aluminum alloy cylinder head will through the up-to-date manufactur- HOW THE CYLINDERS ARE MADE The threads on out the air-cooled be screwed and shrunk. ing plant that turns illustrations the upper end of the cylinder are not cut aircraft engines of the type made famous ONE of the accompanying shows the progressive stages through by means of a die or lathe tool, as the by Col. Lindbergh in his memorable flight may surmise. Since that time which one of these air-cooled engine cylin- mechanically inclined reader from New York to Paris. The threads are milled on the steel cylinder sleeve by a milling cutter, the cutter and the _ HREADS MILLED ON steel sleeve revolving in opposite directions. The milling cutter revolves at high speed, while the steel cylinder makes but one revo- HONING & FINISHING lution while the threads are being put on. Finally the cylinder sleeve, after being carefully inspected and checked (this checking with micrometers or specially prepared gauges occurs after each successive machine operation) passes to the end of the machine shop where the cylinder head is screwed and shrunk into place and where it is honed by a revolving honing tool, which slides up and down inside the cylinder, while it simul- taneously revolves. When the cylinder is finally finished, the inside is as smooth as famous air-cooled engines Evolution of one of the steel cylinders used in building one of the a mirror, and ready for operating service. used by Colonel Lindbergh in his flight from New York to Paris. The steel forging is partly on the exterior of the steel shell (3), by means machined, and then the cooling fins are turned RODS a special lathe containing three sets of tools placed 120 degrees -apart. Cap threads on the THE CONNECTING of is then honed and polished (e). cylinder are milled on (4), and the cylinder THE connecting rods in the air-cooled engine are very strong, yet relatively this same engine has become famous through- ders passes from the time it arrives at the light. They are not made of aluminum but out the world, it having been used as the receiving department of the plant in the form of a steel forging, as one of the diagrams power plant on most of the trans -oceanic of a steel forging. As may be surmised, a herewith shows. In this particular engine flights, whether over the Atlantic or the considerable part of the metal is eventually the connecting rods are machined all over Pacific. machined off of the original forging by the and represent a very fine specimen of the The air-cooled engine is the logical one machinist's art when finished. The round for airplane propulsion, owing to the fact ends are milled off in a milling machine and that no water has to be carried for cooling for that matter so are the sides and the the cylinders. There are also a number ff.i.13.111.113M1 countersunk portions on two of the sides. of other important factors such as a reduc- The two bearing ends of the connecting rods tion in the weight of the plane itself, when are drilled out and then reamed out. After- use with an air-cooled ward suitable bearing sleeves are shrunk it is designed for STEEL MILLED engine. The Whirlwind engine, made ` into the ends. The amount of metal ma- FORGING OFF TO FINE connecting famous by Lindbergh and other notable pi- rFIN15H chined off of the forged steel lots, confuses many people when they first rod may be quickly perceived when it is said see pictures of it, as it somewhat resembles that the finished rod weighs only about rotary engine on 1/20th as much as the rough steel forging. the old Gnome (French) MILLED which the cylinders revolve. In the Ameri- As in the case of the cylinder machine opera- OUT rods are checked re- can built air-cooled engine here under dis- BEARING tions, the connecting cussion, the cylinders are stationary, but are SLEEVE peatedly as they progress through the various air-cooled by the great rush of air past the manufacturing stages. fins on the cylinders and on the cooling TESTED cylinder heads. HOW CASTINGS ARE So popular has the new air-cooled engine THE aluminum alloy castings constituting become that this concern, whose plant is the main crankcase sections of the engine at Paterson, N. J., is now carrying complicated, so far as the foundry located One of the connecting rods is shown above in are quite out a new five million dollar expansion pro- its evolution from a heavy steel forging to work is concerned. The molder who under- gram and large new factory buildings are the finished part, the metal removed repre- takes this class of work has to be a real It is interesting senting nineteen -twentieths of the original at present being erected. forging. to note that during the month in which Col. his famous hop from New PRESSURE Lindbergh made fins York to Paris, only 35 of these engines time the finished cylinder and its cooling GAUGE --~ One of the first operations on were turned out at the factory ; in June are formed. which will eventually form TO SUPPLY-- 138 engines were turned out; the steel forging _ of this year, of in July, this had been increased to 150; and one of the nine engine cylinders, is that as shown at 2 in the by December 1928, 250 engines will be machining the ends each month. The officials of the accompanying diagram. This provides an turned out of the casting on concern stated that when all their new f ac - accurately finished part have been completed the which the successive machine operations are WATER OR tory buildings operation, COMPRESSED AIR monthly production of air-cooled engines based or keyed. As a preliminary the inside of the steel sleeve is bored out. will be 500 engines. tooling stages, GAS PASSAGE Most of the parts on the modern air- After passing through several here being the smoothly finished shell still lacking its cooled aircraft engine of the type lathe made of an aluminum alloy, cooling fins, is gripped in a special considered are chuck and as will which possesses nearly the same strength as by an internal expanding is only slightly be seen in stage 3, the cooling fins, each mild steel, while the weight thick, are than that of aluminum itelf. Many one of which is only 3/64ths inch --PLUG greater steel forging by a triple difficult problems were encountered at first cut from the solid aluminum alloy, set of tools as the picture shows. Each in melting and molding the holders holds is a very peculiar metal. Only one of the three sets of tool as aluminum in number to that stressed parts of the engine are a set of tools equivalent through the aluminum alloy the highly the cylinder. Al passageways made of steel, the members made of this of the grooves on castings are tested either with water or com- principally the cylinder sleeve One of the next operations after the cool- pressed air, any leaks due to cracks or sand metal being turned on the solid steel holes being indicated on the pressure gauge. and cooling fins, the' connecting rods and ing fins have been

www.americanradiohistory.com Science and Invention for November, 1928 591 Engine Was Manufactured the Air -Cooled Engines Are Designed and Built SECOR

expert in this line, as the cores as well as gasoline engine design, the pistons are turned the molds are very intricate and a number of a few thousandths of an inch smaller than passageways for gas and oil are cast integral the bore' of the cylinders, and when the en- with the crankcase. gine is assembled, the four piston rings are The passageways for oil, gas, etc., in the placed on the piston before it is inserted in castings are tested by means of water and the cylinder. Three hammered cast iron in some cases by means of compressed air, rings are placed on each piston together with as one of the accompanying drawings shows. one oil wiper ring. As shown in one of One end of a passageway is plugged up and the pictures herewith, every piston ring is water under pressure, or else compressed air tested, both for its physical dimensions and is applied to the other end of the channels also for its resilience or springiness. A very or channel. A pressure gauge connected to simple arrangement worked out by one of the water or air system shows any leakage the factory engineers, and utilizing a stand- in the passageways and as a reduction of ard weighing scale, together with an upright the pressure occurs, the casting is inspected arm and a lever, enables the inspectors to for cracks or air holes. If any fault is push down on a piston ring, and when re- found, the part is rejected. leasing the lever, the spring rebound caused by the resilience is CYLINDER HEADS SHRUNK ON of the ring read on the scale indicator. This rebound is usually UNLIKE the ordinary automobile engine, about eight pounds. which has the cylinder head cap bolted While being shown through the plant re- in place with a gasket between it and th e cently, the writer was handed a finished pis- Every engine is tested for a number of hours cylinders, the cylinder heads on this air ton which had been rejected by one of the before it is shipped. Accompanied by a cooled aviation engine are shrunk and inspectors after being machined. It was mighty roar the engines are put through the screwed on. These cylinder heads third degree, the engineers checking the fuel are heated practically impossible to find any flaw in consumption, temperature, and other factors n an oven as shown in one of the illustra the aluminum alloy piston which might have every few minutes. tions herewith, so that they expand suffi caused the inspector to reject it. A tiny ciently to enable a mechanic to screw th e hole about one-fourth the size of a pin head as to the noise the engines make when they cylinder head on to the threaded end of the was finally pointed out on the lower edge of are placed on the testing block. On the steel cylinder sleeve. The cylinder sleeve s the piston, and for that writer's recent tour of are not cooled in any special manner, bu tiny defect the inspector the plant at Paterson, are left at room temperature, or about sev had rejected the piston N. J., where the Whirl- my degrees Fahrenheit. When the alumi and dispatched it on its wind engines are built, lung alloy head castings, which of course way to the scrap pile. it was quite a surprise 1 lave been machined and finished previously This will give some idea to hear the tremendous are heated in the manner explained, they as to the rigid inspec- roar these engines make xpand several thousandths of an inch, and tion of the parts used in when they are on test. t is then an easy matter to screw them in this famous motor. About a dozen of the place on the cylinder. In this way an ex- The engine crank case 225 horse-power en- remely tight joint is effected between the has a number of bronze gines were being tested, cylinder and its head. In the Whirlwind bushings or bearings together with one of engine the valves are mounted in the head fitted into it and these the new models, known If the cylinder, there being one exhaust valve are shrunk into place in as the Cyclone, which and one intake valve. These are mounted at a similar manner to the develops 525 horse- a n angle, so as to give the largest cooling shrinking of the cylin- power. The engine test a rea possible between them. The engineers der heads into position. buildings are small who have developed the design of the air- The aluminum alloy Every piston ring is accurately tested. brick affairs with extra c ooled engine of the type here being de- casting constituting the thick walls. The engi- s cribed, have performed a wonderful service crank case is heated, which expands the neers in charge of the tests are stationed which aviators everywhere are thankful for, hole, and the bronze bushing is then dropped in small instrument rooms, the instrument p articularly in the design of the valves and into place. To make sure that these bushings rooms and the engine compartments being t he lightness of the engine, its superior power will not become loose at some later date placed alternately along in a row. Large f or a given weight, and the extremely strong when the engine is in use on an airplane, iron pipe manifolds are provided, into which c ylinders and cylinder heads. It will be they are also keyed with a small steel pin the exhaust pipes of the various cylinders r emembered that in some of from the motor are connected. The ex- t he early flights cylinder heads .111111111111111311111111111111111111188888 111. BEARING RING haust gases are carried through the large RING n ow and then had a habit BEARING LOCKED IN CAST Bearing rings of KEYED IN manifolds and the connecting pipe system, h lowing off ALSO ALUINUM ALLOY are shrunk into and, happily, just PLACE ENGINE -FRAMEBY the engine cast- so that the discharge takes place eventually missing the pilot. EXPANDING (BYNG)BNHEATI ing, and they about thirty feet in the air, just to the rear are also keyed, of PISTON AND RINGS so that if they the test rooms. should become The engineers can keep a sharp eye on ALL automobile engine en- loose SECTIONAL they can- the engines while being tested for hours thusiasts will be inter- VIEW not get out. at a time through heavy glass windows placed ested presumably in the style in the thick brick walls separating the engine cf the piston and the piston rings used in the driven into place between the bronze bushing compartment from the instrument room. On remarkable engine made famous by Lindbergh and the alloy casting. the wall of the engineers observation room, and other notable pilots. The Whirlwind there are a host of instruments TESTING THE indicating motor has aluminum alloy pistons which ENGINES the speed of the engine, the temperature of are cast and then very carefully and accu- IF you have never visited an aircraft the oil and air, the revolutions per minute rately machined engine to size. As in regular plant, you will have practically no idea and other important factors, all of the ALUMINUM ALLOY HEAD meters being read CYLINDER -HEADS BEING HEATED ,1111111111111111111.11111111111111111111111111111111111111111111,1 every few minutes and EXPANDED BY HEATING IN OVEN DRAWER this data tabulated by the engineers on a AND SCREWED ON One of the most interesting operations in the special report sheet. Stop watches and slide manufacture of the air- rules are also necessary in making up the cooled engines is that reports, and so great is the continual roar involving the placement of the engines of the cylinder heads. that the engineers usually The aluminum alloy head wear special ear protectors, similar to those casting is heated in an used by the artillerymen during the World oven, as shown at the \Var. left. When heated and It is almost impossible thus expanded to the to describe the proper degree, they are tremendous roar of the mighty Cyclone 525 screwed on cylinder. horse-power air-cooled engine, which the (Continued on page 637)

www.americanradiohistory.com Science and Invention for November, 1928 How to Save Coal! By C. D. KEELY

SHORTLY before he died, Charles P. Steinmetz, the Electrical Wizard, said: "Our present structures are causing annual leakage costs of literally millions of dollars worth of heat. The home of the future will be scientifically built from the standpoint of heating." A statement, equal in significance to that of Mr. Steinmetz, has been made by the Bureau of Industrial Re- search, Washington, D. C. This is the statement: "The fuel consumed in 15,000,- 000 homes in northern states is fully 30 per cent, and probably 50 per cent more than would be necessary if standards were maintained in materials. Many homes in Amer- R ica have a fuel cost equal in twenty-five z; years, to the first cost." Explanation for the emphasis now being placed, by homebuilders, contractors and architects, on the necessity flit- thermal insulation of residences and other buildings is to be found in the two statements just quoted. Dr. Steinmetz said that heat losses are costing America millions of dollars every year; the Bureau of Industrial Research, says that some 30 per cent of the fuel in northern homes is wasted. consumed Dry fill insulation is placed between the attic Heat. which is fuel, is money. Hence the Above-dry insulation being poured joists. Note pipes imbedded in insulating behind the gypsum wall board. recent development of thermal insulation. material. which has for its aim and an insulated build- the utilization, the ATTIC SPACE'. ing can be described saving, of a part of NOT OCCUPIED loosely as one in the heat that is lost SS° WASTED HEAT which the heat, gener- from uninsulated n n X11 ated in the heating structures. CEILING JOIST plant, is isolated. It 80° LATHS is not, of course, de- THERMAL /a" PLASTER:. sirable to entirely iso- INSULATION late heat in any building. A condition of No convenient defi- perfect isolation would nition for thermal in- not be a healthy one. sulation is to be found. Nor is it practicable Thermal, however, SS- 65° to attempt perfect means pertaining to DRAFTS heat isolation, for the heat; and insulation reason that inevitable means isolation. Ther- COLD FLOORS'. avenues of heat -escape, mal insulation, then. such as doors and win - can be taken to mean, UN INSULATED HOUSE INSULATED HOUSE (Continued on the isolation of heat: The efficiency of an insulated and an uninsulated house is compared in the above illustration. Page 669) A Flying Sailing Boat ABOAT which resembles an airplane wing which moves from right to left under wing in much the same manner as is done more than it does an aquatic craft has the power of the operator. In changing with airplane ailerons. The photograph in recently appeared in Germany. It is the its course the boat relies upon change in the center shows how the wings may be invention of Friedrich Budig who is shown wind pressure which is accomplished by tipped up or down by the operator. The in:the photographs demonstrating the craft tipping either the right or left half of the usual type of rudder aids in steering the before a number of scientists. The boat has boat as the photos show and as becomes a pontoon arranged on either side and a apparent from a study of them.

Above is a front view of the new flying boat being demonstrated to a group of German scientists. Note angle of wings.

The illustration above shows the inventor, Friedrich A three-quarter front view of the boat appears above. Budig, seated in his novel craft. In appearance it resembles an airplane.

www.americanradiohistory.com Science and Invention for November, 1928 593 Entertaining with Hypnosis

Astounding Yet Harmless Thrills Which You Can Accomplish. Your Friends Will Be Surprised Here the subject is commanded to twiddle his thumbs and then told he cannot stop. He continues the thumb movement because he cannot do otherwise. By KENA MURAY The subject of this series of simple hypnotic experiments will find his eyes practically T is the purpose of this article to ex- glued fast and it is impossible to open them plain, in as simple language as possible, until commanded to do so. a few of the inner secrets of entertaining with hypnotism so that the reader, notice that the eyes of the subject have without special training or inclinations in taken on a drowsy look. Then is the time this direction, can easily present experiments to make a positive statement that the eyes of a humorous and scientific nature that are closing tight, fast shut. When this is are sure to mystify and entertain at parties accomplished, massage the eyelids with the and social gatherings. thumbs several times, repeating over and It is first important that the reader under- over: Your eyes are glued fast shut, and no stand that no attempt is made to acquaint matter how hard you try, you will find it hiin with the deeper truths of this science. impossible to open them. The subject will Rather, for the purpose, it is merely desir- immediately commence making ludicrous able that we skim the surface wherein no faces in an endeavor to open the eyes, but special ability or training are necessary, and they remain tight closed, nevertheless, due the reader is cautioned against attempting to the suggestions that they shall do so. td delve further into this work, beyond the Allow this comedy to run for several mo- experiments described, unless under the in- ments, then snap the fingers near the sub- struction of an experienced and capable in- ject, at the same time announcing in a clear structor. This is in order to avoid any com- voice, Awake! when the subject will sud- plications which the neophyte would, with denly open the eyes and a foolish, half sur- his or her lack of understanding of the prised look will spread over his face. deeper phases of the science, be at a loss to It is interesting to note that the subject is cope with. not deeply hypnotized, but is just as awake SIMPLE HYPNOTIC EXPERIMENTS as others in the room, although he has his In this effect the subject's arm or leg is mind concentrated on one single idea. It is AMONG the experiments that always made so stiff that be cannot bend it. The the snapping of the fingers that breaks this cause hilarity when presented at social hypnotist requests him to try. train of thought and releases the subject gatherings as an impromptu entertainment, from the impression that it is impossible to and do not require much practice, we list 5. Making a spectator's arm or leg to be- open the eyes. the following: come stiff so he cannot bend it. DRAWING A SUBJECT BACKWARD 1. Causing a spectator to lose the power These effects do not depend upon any of opening his eyes. magnetic powers of the performer, but are THIS effect is merely a repetition of the 2. Drawing a spectator backward by rather the result of appropriate suggestions foregoing effect, the only difference be- seeming magnetic power. heeded by the spectators themselves. ing that the subject is impressed with the 3. Spectator cannot unclasp the hands. This will be readily understood when it (Continued on page 660) 4. Causing automatic movement.. is explained that the brain of a human being cannot, under ordinary circumstances, concentrate on more than one idea or suggestion at one time. Thus it is that if a certain, fixed idea is strongly impressed on the consciousness, everything else is disre-

garded for the contemplation of . this one idea. HOW TO PRODUCE THE EFFECTS CAUSING a spectator to lose the power V of opening his ór her eyes. First, select a subject who you are sure will cooperate with you fully and without antagonism. Cause the remainder of the spectators to be as quiet as possible. Seat the subject in an ordinary chair, and instruct him to relax completely. Both feet should be on the floor and the hands crossed in the lap in a relaxed and comfortable position. State to your subject in a clear voice that his eyes are becoming tired and drowsy, that they are heavy and sleepy, that the eyelids are slowly closing. Keep a running fire of suggestions along this line, never allowing your subject a chance to think of anything but what you are suggesting. is not neces- clasped in It Hands front of him with the arms sary to make passes or to stare Here a subject is being apparently drawn rigid and the muscles tense, the subject can - at the sub- note release his hands ject as if you would hypnotize him. backward. Suggestion causes him to lean so even when dared to far back that he finally topples over into attempt it. After a few moments of this, you will the arms of the hypnotist.

www.americanradiohistory.com 594 Science and Invention for November, 1928 Science Probes Spiders' Secrets Engineers Will Accomplish Wonders When Science Reveals to Them the Spider's Secret By UTHAI VINCENT WILCOX STIENCE has been discovering some small frogs and snakes, lizards, and even new facts about the spider. Whether bats. He found some of the results hard to or not this creature ever reached our believe, and, as a true scientist, waited a earth from some other world, as some long time before announcing the results of may believe, scientists are agreed that the his own conclusions. He tested some spiders spider is supreme in cunning, ruthless by taking a dozen tadpoles and three tree - ferocity, inventiveness and courage. frogs. H. G. Wells once said that if man ever Taking a jar with the tadpoles swimming lost his mastery of this planet, the next race in the water and a bit of a tree branch to to dominate it would be the spiders! keep the spider and the frogs out of the Mr. Wells is hardly a scientist, yet Dr. wet, he saw that the spider soon ate nine E. W. Gudger, of the American Museum of of the tadpoles, and then made a meal of Natural History, who for years has been one of the little frogs. From this he ob- studying the spiders, now announces the reserved spiders about ponds and small bodies sults of his varied observations, which would of water. It seemed true that tadpoles and make of Mr. Wells a prophet. Experi- small frogs are favorite dishes of hungry ments with spiders and careful watching of spiders. When the spider wants something various kinds of spiders show an intelli- to eat, he goes fishing. Even minnows have gence that leaves mankind amazed. It is been known to vanish from an aquarium if doubtful if the average human being could a large spider is about. begin to compete with the spider for en- But spiders, Dr. Gudger found, will even gineering skill and inventive ability. attack snakes. At Batavia, New York, a So important is the study of the spider small ringed snake, nine inches long, was that the United States Department of the found trapped by a spider in a cellar. The Interior has been making an investigation spider, its body hardly bigger than a good- of the spiders' webs. They found that a sized pea, had spun a web in the form of by a photo- silken thread, spun spider, when In Fiji, Trobriand and New Guiana, the na- an inverted cone, from the tip of which hung graphed through a microscope that enlarged tives use spiderwebs as fishing nets. On the a silken cable of about the thickness of it some two thousand times, appeared to be latter island a native erects a stick, as indi- ordinary sewing silk. By this cable the horsehair. cated in the illustration above, and puts this but the size of an ordinary where spiders are thickest. They weave the snake vas found suspended, still alive, its net right in place. mouth muzzled with multiple strands of THE AMAZING STRENGTH OF web, and its tail tied by means of more SPIDERS' SILK itself. The Interior Department is now ex- silken cord. ON the other hand, a human hair, mag- perimenting with the spider silk, which is Dr. Gudger also tells of a mouse that nified on the same scale, would be six thirty-two millionths of an inch in diameter, \vas snared by a spider. Apparently the and a half inches thick. This is comparative, yet incomparably greater in strength than snaring was accomplished at the start by

SPIDERS WEB ENLARGED The spider's web is often as as 2000 X This diagram thin HUMAN indicates the com- thirty-two millionths of an inch in ORDINARY parative size of the spider's web en- diameter. This means that if It were HORSEHAIR HAIR larged two thousand times with that enlarged two thousand times, It 2000 X of a horse hair and the human hair. would be as big as an ordinary The comparison is relative in borse hair. A human hair enlarged strength also. A spider can, by its the same number of times is 6%: thin thread, bind animals several inches in diameter. thousand times heavier than itself. ACTUAL SIZE Jz 1.000.000 INCH as well, of the relative strength of the two. that of any cord or rope that man knows winding silken threads around the tail of The spider, with such an apparently fragile how to make. the rodent, perhaps while it was asleep. and transparent wisp of line, is able to bind Dr. Gudger, in his studies, tells of how Anyway, the mouse was securely tied, and animals several thousand times larger than he has witnessed spiders attack tadpoles, the spider, its web located beneath the table,

After illustration, American Museum Natural History Left to Right: 1. The spider started from a branch above A and dropped to Lion of the web. 2. The next step in the operation was the laying down another branch below B, spinning a thread and fastening it. She then of the primary spiral, which is shown in this plate and which ended at L. climbed on this thread to the upper branch, crossed over to a point above C, All of these threads consist of smooth, tough silk which is not sticky. From and dropped to a point below D, making a strand as before. Then, going this point on, the spider uses the sticky threads which constitute the real to E, she fastened one end of a strand and, spinning it behind her, went snare. 3. The details of putting in the first of the sticky threads vary across by way of the upper branch to F. She then went to the upper greatly. The spider started at M and its course may he followed by the branch and dropped to this E -F strand, fastening the new line at point H. letters to -V, from V she continued in a regular spiral until the primary This pulled E -F up slightly. The next strand which she put in was from spiral of smooth silk was reached. She then cut away the outer portion of point I to a point on the lower branch below J; pulling this line made the primary spiral so that she might have more room for the snare. 4. The another angle in the cross strand E -F, as did the following line from K process of cutting away the primary spiral and putting in the sticky spiral to B. 'These last two strands were fastened near their center by a bit of is shown about half finished on this plate. 5. This plate shows the silk, and the remaining radii were put in by moving about on the founda- complete web with nearly all of the primary spiral removed.

www.americanradiohistory.com Science and Invention for November, 1928 595

to the air, to the water, to the needs of its SPIDER, HERE, LETS OUT WEB appetite that gives the spider the respect, IF WIND IS FAVORABLE if also the fear, of mankind in general. Dr. Gudger observed a spider making a THREADS ìl web. He said that a spider perched on a twig fifteen feet above the ground and wish- ing to throw a line to another twig twelve feet away, will either take note of the direction of the wind and use it, or will lower itself to the ground, running across to the desired spot, fasten the thread to it *SPIDER and then pull in the slack until the first line is taut. After that it is a simple matter of casting other lines at right angles and paral- SHIP HUNDREDS lel, then dropping down or climbing up and OF MILES SEA OR FASTENS IT HERE pulling in the slack, a web is spun that will ANDPULLS IT TAUT 15 FT catch the needed food. =c The spider lives in a world of an abso- female is the fighter, Frequently a spider will let out its web so lute matriarchy. The that a favorable wind will carry it to an- the bread winner, and the autocratic mon- other twig, branch or flower some distance arch. The male is an undersized, meek little I,I Ji away and will then proceed to weave its is likely to be eaten. web or a spider may fasten the web to one creature, who plant, drag it along the ground, climb up The lovemaking of spiders is a strange rerezk--41111111W4 .. another branch and pull it taut. procedure unlike that found in any other world of nature. Matches are usually made ttirtli showed its engineering skill which led to the at a kind of marriage fair in the light of the üeseezece prophecy of H. G. Wells. By a loop, the moon. The magic of the white sorceress mouse, despite its struggles, was hoisted off seems to reach down at least that far in the floor into the air and hung there wholly the scale of animal life, for when the moon's helpless. rays are on the forest paths or the rocky '1J111I11'ü USING A SPIDER WEB FOR FISHING IT is this fine, colorless rope which, coupled the by skilled engineering ability, makes Ships hundreds of miles at sea have found spider's work so successful. Even man spiders as aviators. The spider lets out a takes advantage of the spider's effort and number of silken threads and is carried by is fact that caused them on a favorable breeze. Extra threads uses the web. It this enable him to ascend. Taking in some of the scientists of the Department of the In- them helps the spider to descend. terior to begin their investigations. It is in New Guinea where the Papuans use spiders' webs for fishnets. The spider certain to touch another. When this hap- which is found there is a forest species and pens between males, they may stroke each spins giant webs six and seven feet in diam- other and pass on. But when a male and eter and woven in large mesh for the catch- female meet, they perform the gesture in ing of small birds, as our house spiders a dignified, meditative way, as if sizing catch flies and moths. each other up for further acquaintance. The primitive Papuan goes to the forest Either may decline this, in which case they where the spiders are thickest and sticks go their separate ways. If mutually at- upright in the ground the stem of a long tracted, they stroll off together. has and pliant bamboo, the top end of which SPIDER LOVE MAKING been bent over and tied so as to form a large loop. This loop makes a convenient ALL this is equivalent to an engage- frame in which to build a web and the In an experiment a spider was placed in a ment, and it may be either short or spider, dark brown, and about the size of a glass jar. Not only did she catch and eat a long. It may end in marriage, or a break- frog also in that jar, but fished for, naught up. While it lasts, the couple devote their hazel nut, with hairy legs that spread about and ate tadpoles. two inches, seeing the ideal place for a web, whole time to each other. They stand to- soon takes advantage of the loop left by gether for indefinite periods, stroll together, the native. slopes the spiders give themselves up to turn aside for no apparent reason, and loiter The Papuan then takes. the net which has 'lovemaking. aimlessly, for all the world like country been presented to him and, going to a nearby Light seems to produce in spiders a strange lovers in Maytime. stream, catches himself some fish by scoop- ecstacy and they give expression to it by They quarrel and make up again. But ing them up with his spider's net. The peculiar movements which some have called mostly they seem to reflect upon the seri- beauty of the net is that the water does not their love -dance. This is a solitary affair, ousness of matrimony. The fact of the mat- seem to hurt it, because the threads are but it serves as a means of introduction, for ter is that he cannot be blamed for this, for ' coated with a gummy substance that is in moving about, one individual is almost the lady who is so nice to him as a sweet- waterproof. heart usually makes a meal of him as a and AVIATORS wife; she cannot.he SPIDER blamed, for she is not only choos- If man points to his mastery of ing a husband but a dinner. the air, the spider can show that Insect observers have discov- he has, for untold cersturies, used ered that human society is not aerial navigation. Many spiders alone in being afflicted with the are skilled aeronauts. Almost masher. The insects have him, any warm day will show a spider too. The human specimen may in the act of taking a little joy even be a reversion to insect type, ride through the air. Climbing to in which case it is more exact to some elevated place and letting call him an insect than a shrimp, loose a number of threads, the a lizard or a cake -eater. wind carries the spider for a Fabre tells of one such male pleasant trip. vamp among the spiders. These The spider, Dr. Gudger ob- insects are formal and cere- monious in their courtship and served, is able to descend at a The diagram above shows a sectional view of the abdomen of a spider convenient time by reducing the and indicates the spinnerets and the glands communicating therewith. this specimen wandered abroad in sail -spread, so to speak, and tak- the moonlight after the manner ing in some of the threads. Then f his kind, observing all the slowly settling a silken line is niceties of the ladies he met. But thrown out as an anchor. These -_ it was noticed that he had a spider ships of the air are some- frivolous way with him, and times found at great heights. whether this was the reason or Even ships at sea have found not, he wasn't well liked. He was them hundreds of miles from turned down by one female spider seemed land. The upper view is a magnified smooth glossy thread; the lower, a thread after another. None to It is this quality of adaptability with viscid globules. (Continued on page 668)

www.americanradiohistory.com Science and Invention for November, 1928 Inventors Ease Products of Inventors' Minds and Engineers' Skill By RHYS G.

HIS bachelor writer was once observing his little niece, June, as she romped about the house, when he suddenly made the discovery, amazing to him as a bachelor, that she was wearing a little undergarment of rubber, designed by some thoughtful inventor, to promote comfort and cleanliness for the baby that wears diapers. That's when the idea for this article on inventions for comfort and health of the baby was conceived. Further investigation revealed that there is now on the market a soft, comfortable, side - pinning diaper that gets away from the time-honored three -cornered dered. This is a clever product of the inventor-a knitted, elastic fab- ric that easily is adjusted to every movement of the child's body, thus method and that is easily laun- promoting cleanliness. This new diaper may be put on while the baby is standing or while the infant is reclining, an added convenience for those who travel. They are quickly pinned at the side. The article is not here illustrated. NEW HIGH CHAIR The above photograph shows one of the HERE is a new type of high new folding bathtubs for babies. It will be observed that there is a tray in front 1 chair, with an extraordinarily for holding the sponge, soap, talcum pow- wide and heavy base to promote der, and also a bar for the towel. The safety. This has an adjustable tub itself is of rubberized canvas, with a top that can be folded over the tub and rest for the tiny tot's feet and which then presents a soft surface on legs, has a padded seat and a low which to rest the baby while drying. The back. This low back is intended entire device can be folded up and put away. to eliminate danger of baby bump- ing the head. The chair has a cross strap to help hold the child' and has a tray across the arms for food or for toys. Under the seat are several compartments, giving ample space for keeping toys, blankets and other baby needs.

A DESIRABLE CRIB ACRIB was recently introduced which has a cover that may be slid end -wise along the top to be used to hold baby while being dried after a bath. The top is of canvas, over a wooden frame, and there is a drawer for infant's odds A new This photograph shows the baby being placed on the top, which has and ends under the crib. been swung in place over the portable bathtub folding tub of canvas includes a drying and dressing tray that may On the left we see a new type of chair for the youngster. This has a low back, so that the head cannot accidentally be struck against be placed over the tub. This light it, a toy or food tray and adjustable foot -rest and a spacious com- and easily carried tub may be partment for the storing of kiddie clothes or toys. Notice in par- placed in a laree size one or it ticular the very wide base on this chair. It bas been so designed is to promote safety. may be used elsewhere. Water

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Above: A form of harness for the child designed to hold the infant safely on a crib or a bed, and yet so constructed as to permit of freedom of movement in all directions. With it the child cannot roll out of any bed. At the left we see an improved style of bottle holder for the youngster which will hold the bottle in place even if the child pushes it away. It can be attached to the crib, carriage, or chair. (Name of manufacturers

www.americanradiohistory.com Science and Invention for November, 1928 597 1VIothers' Cares Lighten Burden. Baby's Life Made More Comfortable THACKWELL drained from the bottom. It includes facilities for holing towels and soap and baby clothes. Made to be folded into compact space when not in use, a new crib has been invented that can be completely enclosed so that flies or mosquitoes cannit pass through the screened sides or top. This can be opened at sides or top, too, on occasions when baby is receiving company. Being on rubber -tired wheels, it is easy to move and quiet. This appears in folded and open form. The mattress can also be raised or lowered. MILK BOTTLE HOLDER ALONG, fle" ible arm of metal to hold a milk bottle securely, even though baby tries to push it away, has been invented to promote safety. This may be clamped to a chair, crib, buggy or almost any other place, and it bends easily to the touch of the baby, but it holds the nursing bottle tightly clamped so that a mother or nurse need not constantly be on the alert when the infan_ is feeding. There is a new and cleverly designed harness to keep baby from falling out of a crib, davenport, Pull- man berth, steamer berth, or other place where the infant might fidget around.

MILK BOTTLE-KEEP WARM AKIT containing several feeding bottles that can be filled and kept at constant temperature in it for a long period has been produced so that mothers will not need to worry about feeding a baby on a long journey. There is a safety walker with a swing- ing seat that teaches the child how to Above we see two views of an infant's crib, the walk and which has uppermost view showing it folded and being car- handle so it can ried upstairs, while the lower shows it occupied. a It is entirely screened. be pulled by an adult. Several new types of cribs for use by baby in motaring with the family have been introduced. Ft* Some can be folded A kiddie walker away when not oc- and stroller which cupied. grows with the child. It can be An attachment for adjusted to many the family scale so heights a n d is that mother can This shows a view of the kiddie's crib with provided with a weigh baby on it has the mattress raised. It also indicates the handle that makes construction of the entire device. Screen - a kiddie car of it, been marketed. ing excludes mosquitoes and flies. and also with a nntinued on detachable han- -(63) dle for convert- ing it into a stroller.

This shows one of the methods employed to prevent a child from rolling out of bed. The farness holds the child securely enough to prevent any accidental injury, and yet loosely enough to allow for freedom of motion. Right, a new form of sterilizer for babies' bottles; this is made of aluminum.

supplied upon request.)

www.americanradiohistory.com 598 Science and Invention for November, 1928 ÚVIE Miniature Sets and Dummy Used in Many Screen Effectively Fool JOSEPH THE express train rushing through the night suddenly plunges downward from an open drawbridge, hurling to destruction its unsuspecting passengers. You gasp, shudder, and possibly scream. When one considers that scenes of this nature are made with miniature sets, ofttimes only about one foot long, the effect upon the screen is nothing short »:. of miraculous. In a New York exhibit, recently, many movie tricks were exposed. Above is an Alpine scene during a blizzard. Corn It takes a great deal of ingenuity and in- flakes are used for the snow and the huge drifts and comparable skill to construct a miniature glaciers are made of common table salt. The moun- scene, tains are fashioned from papier maché thrown over and have it actually look like the cartons for support. The whole width of the set is real thing when flashed upon the screen. only about one foot and yet, when seen on the Many of the dwarf objects are no longer screen, it looks like the real thing. than a man's hand and are constructed The young lady at the right is loaded down w:th a exactly to scale. collection of objects from a railroad shop. All of the objects pictured are imitations. Even the telephone and bottles are dummies, despite their realistic appearance. These props are now being shown in an exhibition of movie tricks in New York City.

T h e illustration at the right shows a holdup in broad daylight on Broadway. Strange to say, casualties,there were no because the pis- tol, despite its vi- cious appearance, is a "dud" and the sledge hammer is made of Above is a faithful miniature of one of Detroit's main thoroughfares. rubber weighing The structures in the foreground are mere doll houses, and the only a few vehicles are small toys built to scale. Scenes taken in the studio ounces. ,g were super -imposed upon this set.

The good ship "Mary Ann" pitched and tossed in a tropic sea while there was mutiny aboard, and nefarious plotting going on in the captain's cabin, which is shown above. The small cabin can be rocked as roughly as need be. It is, however, built exactly to detail and fitted properly furniture. with midget

Unfortunately the cameraman arrived just a moment too seen to take the actual picture of the wreck which will occur in The wreck of the the picture at the left. The waterfall drops only twelve Limited! Bere we see a small set inches into the gorge. The hero is shown rushing to the with the train rushing out of the scene in a racing car, in order to save tunnel at the - watery the heroine from a left, approaching the bridge over the rapids which are swollen grave. Movies of this dwarf set appear real when with rain - thrown upon the silver screen.

www.americanradiohistory.com Science and .invention for November, 1928 599 TRICKS Props Portrayed Here Are Productions and the Audience H. KRAUS Pictures of the actors in suitable positions are taken with a dark backdrop and are then super -imposed upon the pictures of the miniature sets when this is necessary. Scenery moving past a stationary vehicle fools the audience into thinking that the car or train is traveling at a great rate of speed. Dummy or fake props also play an important part in the filming of pictures. Some of them are illustrated on this The dashing hero races with a police motorcycle and gets page and we see guns, sledge hammers, a ticket for speeding. Above are shown all the props of and the like, which the scene. Both motors are tiny replicas of the originals. swords, wrenches, The cars do not move at all, but the back drop rushes are apparently the real thing. Upon past, giving the effect of great speed. The size of the closer inspection, these props are found motorcycle may be Judged by the man's hand, which to be dummies and are usually made up appears at the extreme right corner of the photograph. of wood or rubber composition, light in weight. At the left the young lady carrying a huge gear and a railroad tie. The total weight of the burden is only 7?S lbs. The gear is made of a rubber composition, and the railroad tie is constructed of balsa wood, which is the lightest wood known. The large bolt is also made of a rubber composition which is light in weight.

Here we see an ocean liner foun- dering in the mid -Atlantic. The If you have seen "The Thief of Bagdad," you will probably remem- model ship is ber the magic carpet. This aerial vehicle is shown above, and is no placed in a tank bigger than a man's hand. Wires are provided for suitable manipula- no bigger than a tion of the carpet and figures. bathtub and is rocked by a small electric motor.

The above photograph shows G. Alex Limebaugh and two cf his assistant teclnicians who are at work on a miniature city which they are building for a movie production, in the workshop set up at She exposition. He intends to show some of the tricks of the movie business which help to build suspense ant make drama for the audience.

At the right is a movie prop workshop with a miniature city is the making. The size of the models are shown clearly in comparison with the figure of their constructor. On the extreme right, a section of the mountain set is seen. A small elevate) road and an "L" train are visible in the foreground.

www.americanradiohistory.com 600 Science and Invention for November, 1928 Is Civilized Man Losing His Sense of Smell?

By WALTER RALEIGH

"Fee, fie, fo, fum! Dr. N. E. Mclndoo, of the Bureau of Entomology, U. S. Department of Agriculture and the apparatus devised by him for ascertaining the odors I smell the blood of an Englishman!" which attract insects. Dr. Mclndoo has named his apparatus an "insect olfactometer."

FVERYONE is familiar with the ter- at a hundred yards, or locate his master in told that the cannibals and snake-eating rifying chant of the terrifying giant the complete absence of a trail. tribes of Queensland hunt, by smell, alone, in it has re- a species of boa upon which they live. A the nursery tale, but FOOD MILES AWAY mained for a scientist to discover in SMELLING white explorer, who witnessed such a hunt, it a vestige of truth. DISTANCE, apparently, is no handicap put his nose to the ground and was unable Perhaps, in the days when this fabulous at all to an insect, nor does he need a to detect the odor which the tribesmen were legend originated, people generally had much trail. Boll weevils, Dr. Mclndoo has found, following with ease. better noses thaw those we boast today, but, may be hatched miles from growing cotton, "Certain Peruvian Indians are reported even if they did not, it is really quite plausi- but they can locate it and head straight to to be able to follow a trail by scent as ble that a man-eating monster, such as the it, led by some mysterious faint odor that reliably as a hound. Another writer describes one described, might have been able to pick man, walking through the very field, can- experiments, repeatedly conducted, which up his victim's trail in this very fashion. not detect at all. The same is true of proved that Negroes and Indians recognize

Diagram right: On a level, sandy place in Amsterdam, a boy followed the route indicated by the solid line. This route departed from a tree (B) and ended at a laboratory (L). At T there were two street cars and at H two huts used by construction workers. Upon completion of trip by boy, a police dog was led to the tree, where he was allowed to smell the boy's cap, and then followed the boy's trail as indicated by the dotted line. A strong wind was blowing in the direction indicated by the arrow (W). Between tree and street cars the wind seems to have scattered scented sand, because the dog fol- Above: Olfactory cells (0) and their lowed to the right of the boy's cilia (C) and their supporting cells A track, whereas behind street cars, (S) from Parker; A from man (after trail was followed exactly. Where Von Brunn); from pig (after Alcock); C from frog (after 6 the boy turned to left at X, the chultze) and D from a fish (Jagodowski). as shown dog had some difficulty, the huts, by his windings. Just before reaching bees and other insects. the dog lost the trail, which is to be explained moths, ants, by the fact that many people were walking about, Returning to his discussion of the human persons in the dark by their odors." but he soon found it again. (After Buytendijk.) family, Dr. Mclndoo, in an interview, cited The entomologist at this juncture, how- a number of literary ref erences to the acute- ever, finds it encouraging to note, that the ness of the sense of smell in savages, which civilized nose can be educated and that, even Conscious exercise of the nose being tend to prove that man, living apart from in modern countries, certain persons exist taboo, the human sense of smell may be nature, loses some of his alertness to the who are monstrously clever at detecting and deteriorating, in the opinion of Dr. N. E. world of odors. analyzing odors. Dr. Mclndoo has made a Mclndoo, of the United States Bureau of "Ethiopians," he stated, "and North special study of bees in the course of his Entomology, who is interested in establish- American Indians have a remarkably keen entomological experiments, and, in addition ing a science of odors and rescuing from sense of smell which, in part, accounts for to making some rather startling discoveries disrepute the "Cinderella of the senses." their wonderful ability to trail their ene- regarding the private life of this model in- He points out that primitive races have mies. An old history of the Antilles states sect, has trained himself in their ways to noses infinitely superior to those of civilized that some of the Negroes there can dis- the extent of being able to distinguish dif- people, and that many savages trail their tinguish the footsteps of a Frenchman from ferent hives by their characteristic odors. enemies and hunt their food by the sense of those of one of their own race, and we are (Continued on page 642) smell alone. Animals are even more alert savages. For ages the dog's Section of Olfactometer, to odors than showing insects leaving nose has been considered a paragon among container and traveling noses, but, says the scientist, when it comes out into the two tubes to real hypersensitiveness, the insect walks connected with it. The in any contest. His odor being tested is in away with first honors one of the legs of the sense of smell is the sine quâ non of his Y tube, whereas the existence. other is free of it. In- locate truffles, sects are in a bottle A dog, for instance, can connected with the el- which are a species of fungus that grow factometer via the tube underground, by sniffing at the earth close held in the hand. Oder-. can find his mas- iferous substance enters to where they grow. He through the upright hose. ter by following his footsteps over surpris- Note greater number of ing distances ; but he cannot find a truffle insects in this leg.

www.americanradiohistory.com Science and Invention for V-ovember, 1928 601 Danger-High Vacuum By EMERY G. GREGORY

Below is an illustration showing the type of vessel used by Michael Faraday in carrying out his experiments with the vacuum.

FIVE FOOT COLUMN SOFIRON

In the drawing above a cream can is shown Faraday's vessel was made of standing on end with thin tin,contained c small amount five feet of solid iron Above, we have a photo showing how the cream of water and was equipped with resting on the upturned can was completely disrupted, owing to the a stop-cack. base. vacuum created within.

EACH day we walk in the presence of creamery was brought into contact with the interior with live steam, after which he forces, not unknown, but at least un- full meaning of the mighty force represented dropped the cover back into place. He noticed or unthought of until some accident in air pressure, when one morning, he began started washing a second can. Turning or conversation or picture brings them to the washing of the empty cream cans. He around he found the first can in a state of our minds. A new employee in a Wisconsin had just washed out a can, then scalded the (Continued on page 659) The Magnetic Nail Picker

4' 0,.

8'-y ROAD ` USEFUL SURFACE -'MAGNET/SM `

The magnets The magnet and the area of useful magnet- were designed in sections four feet long. The core of each magnet consists ism in the nail picker are shown above. of a 12 -inch for the magnet is derived from a I-beam, to the center of which Current is bolted a 2 x 2 inches square Ford engine -drives 3 k. w. 110 -Volt D. C., bar of iron. generator. Below, we see the amount of iron and nails collected from various Washington highways.

TO SUPPORT,1i ON TRU-î/f N;<-CHAIN HANDLE

The magnetic nail and iron picker is shown above in operation. The magnet winding consists of 315 turns of No. 7 ROAD double cotton covered Two MILES %0"'r SURFACE square magnet wire. At South of Pullman the left is shown the method of supporting the 9% Ibs. magnets.

www.americanradiohistory.com ( efl 602 Science and Invention for November, 1928 Scientific A Photographic Pictnrizatiou

It is almost impossible to keep up with the rapid strides taken in the field of science. This is truly a scientific age.

Illustrated below to the right is a new Ger- man toy which is propelled by means of a rocket, as was recently done in the case of racing cars. A tiny rocket exploding in the rear propels the automobile forward.

Tourists arriving in Washington, D. C., find a huge portable swimming pool at their dis- posal. The pool is 40 ft. long, 10 ft. wide, and 4 ft. 9 inches deep. As may be seen in the above photo, it is constructed entirely of waterproof canvas supported by a steel framework. The pool is readily portable, and can be set up in two hours' time. Several ladders placed around the edge provide entrance and exit to and from the pool.

The above illustration shows Dr. Burt, who has invented a new device A which may be termed a "Sunhurnometer." The resistance of the skin to the sun is tested by this machine, and it is possible to ascertain just how long one may expose his skin to the sun's rays without injury. In making the test, a small patch of skin is exposed to the ultra-violet rays which emanate from the device. The photograph at the right shows several more of the German rocket toys. Several airplanes and an automobile may be seen being driven by the explosion of small rockets placed in the rear of the toy. With the success of the Opel rocket automobi_e, the German children have discarded their old-fashioned toys in favor of tie new ones, illustrated here.

The above photograph shows nita P,ge, a screen star. hay- 4. ing her voice analyzed At the same time she is being photographed by a movie camera. These tests were made ty the University of Southern California. At the right may be seen the voice record. A permanent record of the voice is made upon a steel wire by means of an instrument known as the telegraphone which has been described in this magazine several times. e »-+

www.americanradiohistory.com Science and Invention for November, 1928 603 Progress of Modern Scientific Advances

On these pages we can portray but a few of the advances made in many different scientific fields.

Virgil C. Anderson, of San Francisco, Calif.; has discovered a new method of marine propulsion illustrated below. Water is discharged from twin pistons under pressure and propels the boa, 7.1r - ward at a speed of thirty miles per 'hour..

In circle below: Humidity regulator.

Above is a inventionnew French known as a dab tail scul- ler.

n entrained person :an cperate the appa- :a*us by simply swing- ing tte tiller back and E forth, as shown above. In the laboratory of the Portland Cement Association in Chicago, a single himen ha.r plays an important part. The slender filamert regulates the humidity of the room in whit. tests on cement are made. the regulator is shown at the left in the small circle. When there is too mu:h maistcre in the room, :he lieu elongates, raising a bar shutting off the hamiditer. When the air becomes dry the humid air is admitted. 4.-Ee Dr. F. Holweck, an X-ray expert is shown at the left operating his machine, which tt=ls exactly how much energy in the form of x-rays is needed to kill a single germ. tome germs are harder to kill than others, and Dr. Holweck asserts that this is probably due to the fact 'that :he X -raya have failed te strike a vital spot.

1111111.11111111111111111,

Tie above illustraticn shows a new device which cures colds by electricity in a few minutes. A high frequency current generates heat. whict penetrates the mucous membranes of the nose. The illustraticn at the left shows a new apparatus for treating diseases by short radio waves. The human body is subjected to the high frequency radio waves which are projected from the apparatus on 4 wavelengths between 80 centimeters and one meter.

www.americanradiohistory.com 604 Science and Invention for November, 1928

Conducted by GEORGE Á. LUERS

TO REDUCE LABOR AND TIME A motor should always - be run long . OF VALVE GRINDING enough to heat up, when making any tests DO YOU KNOW- for worn parts, as a cold motor is always Valve grinding and adjustment is a requi- the numerous nickel -plated parts noisy, and even the most experienced ear site detail of engine care, and means to re- of the car can, be protected through cannot detect sources of trouble in a cold duce the time and labor incident to this the winter with one coat of quick - motor. work are important to the owner who does drying brushing lacquer. Polish the A loose piston is most evident with a full this work himself. nickel, apply one coat of clear lac- advanced spark, while retarding the spark quer, and the nickel will stay bright. will lessen the noise of a loose piston. A Use lacquer thinner to remove this second test for the loose piston, is to squirt in the spring and the nickel will be oil into the intake manifold from an ordi- found none the worse for the win- nary squirt can, this being done of course ter's snows and rains. while the engine is running. Oil will stop the loose piston noise immediately, thus prov- ing the cause of the noise. vith three boards running lengthwise, cross The replacement of pistons or piston pins, stiffeners and four small furniture casters. is usual through the top of the engine after The main feature of the device is the removal of the cylinder head. Be certain of spring headrest. This should be provided the parts, however before installing them. with a sufficiently heavy spring to lift the When a noise appears to come from the head. If one spring is not sufficient two can base of the engine, the owner must determ- be used, or a heavier spring should be ob- ine if it comes from the crankshaft bearings tained. It is possible to modify any pre- or the connecting rod bearings. If the en- viously built creeper, for this headrest, even gine is put on the pull test of working though it is of the metal type, slight changes against the brakes, the screw driver or rod in the details being made as required. method will determine the location most accurately. Above-I, piece of wood; 2, valve holder; 3, If however the crankcase lower cover is metal clips; 4, terminal wire; 5, starting removed, can be in- switch held down; 6, indicates view of the the bearings individually engine, and 7, starter motor. spected, and adjusted where necessary. Worn and improper adjusted valve lifters In many of the new cars, the use of sili - and push rods, are noise producers, but are chrome valves, which are very hard, makes easily detected, being adjusted or replaced by the use of previous soft grinding compounds new parts. almost useless. Select a brand of valve A loose flywheel is a noise that is very grinding compound which is sold for use in difficult at times to locate, this is due mainly grinding these hard surface valves. to the fact that this noise is transmitted to To avoid the trouble of turning the start- all parts of the engine and gives the impres- ing crank, to raise and lower valves to their sion of being loose main bearings. Engag- seats, while either grinding or adjusting, the ing high gear and putting the engine to pull starter can be used. Remove the starter against set emergency brakes, causes the terminal, wedge or tie down the starter noise of loose flywheel bolts to disappear. switch and use the free end of the terminal This same action with loose main bearings wire to make contact with the starter ter- will increase the noise, thus pointing out the minal screw and thus quickly turn the en- trouble. gine. This will be understood by reference Above -1, creeper; 2, leather hinge; 3, inner Noise around the camshaft may be due to to the sketch. tube stuffed with cotton waste, and 4, cush- loose camshaft bearings, loose keys in the A simple valve board, made as shown in ion spring secured with staples. camshaft gear or a loose timing gear. the sketch, has proven of especial value in The test is to place a hacksaw blade or WORN OR LOOSE BEARINGS OR other spacer between the valve work. This is only a piece of wood, PART CAUSING KNOCKS valve tappet and the cut at one end to fit around the radiator cap. valve stem. The pressure of the valve The other end has two small clips to engage There are two usual methods of readily spring will usually cause a loose camshaft the cowl. As many holes as the engine has determining a bearing knock or thump, trac- bearing to run quietier. This test should be valves, are drilled through the board. This ing it to its source, or location in the engine

www.americanradiohistory.com Science and invention for Noveuaber, 1928 605 PEAK LOAD

OLD 1tfatt Boyle stepped out of the How Matt Boyle, old gas plant en- But Matt was not to be pacified. "Loike booster -house and stopped, patched Hell, Oi will !" he said. coat over his arm and dinner -pail gineer, became a hero when the ma- Barry fidgeted nervously as if he didn't in his hand, for a final survey of know what to say next. A coughing burst the works of the Homestead Gas Company. chinery failed at a crucial moment of sound from across the yard saved him He had done the same thing at 3:30 P.M. the trouble. Shattered glass tinkled on the every day for the six years he had been ground and smoke gushed from every win- booster-man-but this was different. Old By E. G. MARTIN dow and crevice of the water -gas house. Matt was through! this was his last look. "Holy Peter'n Paul I" Barry gasped. No chance of his coming back to hang "What's that crazy Wop done now?" He around the works after being fired! Damn pay had been exchanged for rot -gut whiskey. departed on the run for the water -gas house the directors and their retirement rule! Matt's faded eyes brightened as he remem- and Matt followed more leisurely, stopping What right had they to kick out an able- bered the time he fought Red Shaughnessy to set down his dinner -pail and glance up bodied man, just because he was born sixty in the "Palace." Red had been head of the at the holder. years ago, take away the only job he cared Gas -House "Tarriers," until Buck Boyle took Like all gas men, Matt had almost a anything about or was likely to get? him off his pedestal. They had called him superstitious awe of the holder. It was their Not that Matt Boyle needed the money "Buck" Boyle in those days, Buck Boyle real master. Managers, supers, and fore-

"After the next period of re -fueling, Matt took time to glance out at the reached and the demand began to drop off; an hour or more before they holder. Jerusalem, my happy home! It was low! They were fairly on the would be safe. Number Ten groaned and erupted smoke and steam from every peak now, it was 5:30 and half an hour to go before the maximum was crevice. ... Those leaks worried Matt, not because of the leaks, but ..." so much. He'd always had the habit of water -gas maker and king -pin of the works. men could come and go, but the big tank saving a good slice of each week's pay. Men nowadays weren't what they used to was always calling to be filled. Built in Matt had plenty saved up to loaf comfort- be-Wops and Bohunks most of them, even telescoping sections like a folding drinking ably for the rest of his life if he wanted Mexicans. cup, it slid up and down between steel guides, to; or he could raise chickens. All gas Buck Boyle had been water -gas maker rising high as the gas in storage grew dur- men, like all sailors, plan to retire sometime until the new, automatic machines came in ing the night, sinking into the huge, circular and raise chickens. No, it wasn't that. to replace the old, hand -operated sets. Then tank of water as the supply was drawn upon Only-well, Matt Boyle had gone to work they had wanted men with more mechanical to cook thousands of breakfasts and dinners. for the Homestead Company when he was training. Since then, Boyle had fallen to The customers were far away-nebulous eighteen, a raw emigrant lad just over from boiler -firemen, yard -boss, and finally booster - abstractions to the .workmen; but the holder Ireland. He'd been working there ever man, that last refuge of the old-timer. Now was right before their eyes, an insatiable since, and since a gas -works operates three he was out. monster, always having to be fed, always hundred and sixty-five days a year, Matt Before Boyle finished his inspection, Heck ready to seize an opportunity to sink "in hadn't found many outside interests. Barry found him. The plant foreman was the mud." Nearly all the men had been Irish then, obviously ill -at -ease. "In the mud !" That was the supreme dis- deep -chested, black -mustached men who "I was afraid you'd get away before I grace, the ultimate calamity. A boiler might worked twelve to sixteen hours a day in caught you." He paused awkwardly. "You burst, killing its fireman; condensers and blazing heat and fought with each other know, Matt, I hate to lose you. Come down purifiers might clog, stopping the endless like ramping stallions after their week's and visit us whenever you can, will you?" (Continued on page 647)

www.americanradiohistory.com 606 Science and Invention for November, 1928 By "DUNNINGER" DIAGIC NO. 68 OF A SERIES

THE ENCHANTED CANE THE DEMON REFLECTION CIGARETTES AND FINGER THIS experiment differs materially from A SMALL hand mirror is passed for ex- RING TRICK the usual routine of magical mysteries. amination, and when found to be in- It requires no special paraphernalia. In ef- tact is returned to the wizard. A pack of THIS is an excellent pocket trick and playing cards is then fanned out and a spec- can be presented as a spiritual effect. tator selects one and names its suit aloud. The magician borrows a finger ring, and in EMPTY Let us assume that the trey of hearts has been chosen. A pocket handkerchief is next PAPER borrowed and the selected card is placed CONE= face upward on a small hand mirror. The mirror is then given to someone to hold. 42 The affair is now covered with a handkerchief, and when the kerchief is removed the card is found to have mysteriously vanished. On looking through the deck, it is there again located. The explanation ; two cards identical in suit are used. One of these is forced. It is left in the deck while apparently being removed, and the duplicate or prepared card is removed from the bottom of the pack. This duplicate is an ordinary card glued to a small mirror. When placed on the mirror frame it is turned by the magician under cover of the handkerchief.

After rolling up a piece of paper into the form of a cone, the performer puts his hand In this effect an ordinary cigarette is made into it and withdraws a regular walking cane. to rise mysteriously in the air by what one As will be observed, this has been previously can assume to be a mesmeric force. Actu- concealed in the leg of his trousers. ally a hair and a pellet of wax produce the effect. fect the performer displays a large sheet of paper showing both sides thereof. He rolls keeping with his policy of borrowing, he this into a cone, then, holding this cone in also borrows a cigarette. He pushes this front of him, he puts his hand down into cigarette through 'the finger ring, which is the open mouth and extracts a full length held lightly between the thumb and fore- cane which he taps to indicate its solidity finger. Now, raising his hand and making and then passes out among the audience for mysterious passes, the cigarette remains sus- free examination. In order to perform pended in the middle of the ring, and at the effect, a straight cane with a knob at command rises or falls ! Having produced the upper end thereof is provided. This is the effect several times, the magician re- previously concealed within a special pocket turns both borrowed articles intact. The sewed within the performer's trouser leg. explanation is rather simple. An ordinary Thus suspended, the performer finds no dif- finger ring is used and the cigarette is at- ficulty in walking back and forth and need MIRROR WITH PLAYING CARD SIDE tached to a thread with a pellet of wax. `F not arouse suspicion. During the act of By moving the hand further away from the rolling up the paper cone, he puts his hand A forced card is placed on the face of a mir- body, the cigarette is made to rise. When inside and tears a slit through the paper ror covered with a handkerchief and on re- brought closer, the cigarette falls. This is through which the cane can be easily grasped moving the handkerchief, the card has dis- due to the fact that the hair is attached to and removed. appeared! the vest button. A NEW CYLINDER TRICK

!r> 9 ? p 2 < 2 ? Q4 .I2 P - T STRING

. i,m ` .''' 1 ic m.,' I

the magician makes an apple disappear and reappear as often attached to the article to be vanished. By lifting the canister when the hand In this effect object will remain in sight. By stretching the as he desires. The only requisite is a cylinder larger than the object to be is held close to the body the vanished and, of course, the magician's indispensable black thread. It will arm out to full length. the object. of course, remains within the confines of be observed that the thread passes through the side of the canister and is the metal covering. Thus the effect can be repeated as often as desired.

www.americanradiohistory.com Science and Invention for November, 1928 607

Can You Answer These Questions? (Form your own answer before turning to page indicated) 1. If you were awarded the masonry contract to place all the 7. How are movie scenes taken showing a ship's cabin with brick and stonework on the various floors of a thirty -story the ship rolling heavily? How are many different movie skyscraper, how would you arrange to carry on the work "street scenes" taken? How was the flying carpet in as the building structure progressed? (See page 586.) "The Thief of Bagdad" photographed? (See page 598.) 2. Did you know that television has found a new application 8. Does a dog have a greater sense of smell than a man? in the realm of music; that in fact it is to be used this How does the boll weevil locate cotton when it is hatched season to aid in the conducting of two orchestras simul- miles away from the growing cotton plant? (See page taneowsly? (See page 587.) 600.) 3. What were the cylinders on Lindbergh's famous air- cooled engine made of, steel, iron or aluminum? How 9. In producing "movies" with an amateur camera, how are the cylinder heads on this particular air-cooled motor would you show a person diving from a springboard, and secured to the cylinder sleeve? (See page 590.) then ascending backwards up to the board again? (See page 609.) 4. What is probably the cheapest and easiest way in which to insulate your house so as to save a considerable amount 10. What is the simplest test you know of to determine genu- of coal this winter? (See page 592.) ine butter from renovated butter? How can you easily 5. If you simply sit in a chair and close your eyes, and then tell whether a certain fruit jam has been colored with a a person tells you that you cannot open them, do you coal tar dye? (See page 611.) think you could or could not open your eyes? (See 11. If you have ever done any wood finishing, and most of us page 593.) have at some time or other, can you explain how to apply 6. How thick is the strand of a spider's web? Do spiders the well-known French polish? (See page 614.) ever sail to sea by means of their own web threads? Can 12. If the image in a television receiver is observed to be a spider lift objects many times its own weight? (See upside down, how can you reverse it? How can you page 594.) magnify the size of the television image? (See page 618.) Jupiter in a Stereoscope By DONALD H. MENZEL, Ph.D., Lick Observatory HY the brain should synthesize ter's outer atmosphere while the red photo- color. Then it was about 30,000 miles long the apparently "flat" picture seen graphs depict a lower layer. Note the dif- by 7,000 miles wide-large enough to con- by each eye into a view possessing ference in intensity, form, and general ap- tain several bodies the size of the earth. W the depth of three dimensions is a pearance of the same belts at the two dif- After many years of inconspicuousness, it mystery not yet solved by the physiologist. ferent levels. has again become plainly visible, though it The well-known stereoscope takes advantage The surface seen in either case is unques- has not regained its former prominence. of the phenomenon, presenting two views, tionably gaseous-not solid-and the belts The black spot in the upper right is the differing in perspective just the amount by visible are streaks of floating clouds. Heat shadow of the satellite, Europa. In the in- which the eyes are separated. If the two measurements indicate that the temperature terval between exposures it has moved scenes are exactly alike, the illusion of of the planet is extremely low, about 120° enough to vitiate the perspective-hence it "depth" is entirely lacking. below zero, Centigrade, and the clouds are, appears to lie far above the planetary surface. When so distant objects as the planets are very likely, composed of some frozen ma- This method of presenting planetary views studied stereoscopically, slightly differing terial such as carbon dioxide snow. Their is more than an astronomical curiosity. The views must he obtained. Astronomer Wil- distribution in belts is parallel to Jupiter's stereoscopic effect lends a semblance of liam H. Wright, of Lick Observatory, has equator. reality to the picture even beyond what is solved the difficulty in an extremely interest- "The great red spot," one of the best ordinarily observed in a telescope. Many ing though simple manner for Jupiter, allow- known and semi -permanent features is irregularities and odd formations, not at all ing the natural rotation of the planet to plainly shown near the upper limb on the prominent in the flat picture, stand out viv- change its aspect. The resulting photographs violet photographs. Probably owing largely idly in their three-dimensional aspect. The are shown in the accompanying illustration to its color, it is inconspicuous on the red public will undoubtedly await with interest and, in a stereoscope, plainly exhibit Jupiter's views. This spot has been known since similar photographs of Mars and the other approximate rotundity, together with his 1878; from that time till now it has under- planets. slightly bulging equator. gone many variations in size, shape, and Jupiter has a breadth of 87,400 miles and There are two sets is eleven times larger of photographs. The than the Earth, and upper were taken only 1,000,000 times with ultra - violet smaller than the light and the lower Sun. The planets with red. The pro- Mercury, Venus, the cedure was to take Earth and Mars first the right-hand combined would form pair and then, after an insignificant mass an interval of eleven in comparison with minutes, the left- this giant planet. hand pair. During The immense globe this time, the planet's weighs 310 times rotation amounted to more than our Earth, six 2nd two -third but its density is degrees, quite suf- only one quarter of ficient for the stereo- ours. Materials up- scopic effect. on Jupiter are made Notice the decid- of substances lighter edly different aspect than those upon the presented by the re- Earth, but as the spective colors. Ter- planet exerts an at- restrial experience tractive force 2/ indicates that the times as powerful, penetrating power of they are in reality the red rays is heavier and there- greater than the fore weigh more. ultra-violet, hence it Seen in the telescope, , is concluded that the the planet Jupiter top pictures reveal If you have a stereoscope view this picture in the regular position before the two lenses of seems to he envel- the structure of Jupi- the stereoscope, and you will be surprised to see Jupiter stand out in relief. oped in dense vapors.

www.americanradiohistory.com 608 Science and Invention for November, 1928, .; = ,-Z5,727,1;1:-,7,7/7'17

..1'riiMa+N+NNNri+NN:N.. om.eo9iesNc(` ,. J./-.ï-''rG".,/'fs/''/Y.l/'_. Conducted by DON BENNETT Trick Work with Amateur Movie Cameras

serve the purpose of a telephoto lens. One of my customers while touring the Alps, wanted to get a picture of a friend of his who was scaling the face of a cliff. He was so far away that a telephoto lens seemed a necessity, hut my customer did not have one. He attached his iris vignetter and, setting the camera on a tripod, exposed a few feet with the vignetter wide open, then with the camera still running, he slowly closed the iris until the climber stood out as the most important thing in the picture (Fig. 2). The slow contraction of the scene aided this illusion and he seemed to move nearer the camera as the opening grew smaller. The beginning of the scene established the location, a snow-covered cliff amid beautiful scenery, and the slow closing of the iris compelled the eye to concentrate on the subject, the climber. "That is a stunt worth knowing. Are there any other uses for the iris?"

HOW TO FADE ONE SCENE INTO ANOTHER "V OU can make a very intriguing lap- " dissolve with it. A lap -dissolve, you know, is where one scene fades into another, a bit of each scene showing during the A very novel effect has been obtained in one change. With professional cameras this is of the commercial photoplays by mounting A veteran parachute jumper brings to the the camera on a platform suspended from a public eye the thrill and effects which are done by fading out on one scene and then cable. The platform can be moved up and seen in descending to the ground. A movie winding the film back, after which the cam- down, as shown above. camera strapped to his head enables these in on the next scene. Of Photo courtesy 31etroGoldwyn-Mayer. extraordinary shots to be taken. era is faded Photo courtesy De\'ry. course the amateur has no fade-out device in his camera, so he must resort to other (6 SAW a wonderful picture last night, means. If you iris out at a steady rate and one note the footage consumed, you reverse the Mr. Jones." The speaker was FIG. 4 of Jones' newest customers and a per- film and iris in on the next scene. Of course sistent seeker of information. He was amateur cameras are not yet equipped with eager to learn all he could about his new means for turning the film back so we must hobby of movie -making and absorbed input the camera in the darkroom or in a formation readily. He continued, "I wish changing hag, which is a portable dark- I could get some of the effects that the pro- room in which you can work by the sense fessionals do. I'm sure I could make my of touch. You unthread the camera and films more interesting to those who are not wind back the amount of film that it took in them." you to iris out. Then you rethread the cam- A TELEPHOTO TRICK era and set up on the next scene. With the iris full -closed, you start the camera and - HAT is the supreme test of an ama - iris in at the same rate of speed you irised 1 tuer film, to make it interesting to out. This results, on the screen, in two those who have no personal interest in it. circles growing in opposite directions and But you need not worry about your lack dissolving one scene into the next. A little of equipment. There are some very simple practice is needed to turn back the film just devices for amateur cameras, that when used the right distance but you will find it easy properly, enhance the value and interest of DUPLICATING MASK to do. It does not matter if you are a few your films. For example, this "iris vignet- inches off, but a perfect lap gives the best ter" (Fig. 1) has a great many possibili- effect. While designed to act as a fade-out The above drawing shows the duplicating ties. mask which makes it possible to take two "Another good use for the iris is to elimi- device, under certain circumstances it will pictures on one frame or four, as described in the text.

Fig. 2, at the left, shows how the effect of a distant is ob- tainedview by means of an "iris vignetter." The distant figure seems to stand out as the "iris" is closed and compels t h e eye to concen- Fig. 1 above shows a view of Above, in Fig. 3, is Illustrated the "binocu- trate on the the "iris vignetter" used to lar" mask and the effect obtained when this subject. imitate telephoto shots. is used while taking the pictures.

www.americanradiohistory.com Science and Invention for November, 1928 609

nate objectionable backgrounds when filming two feet into the dish containing the solu- a close-up of a person. Just the head or tion and slowly withdraw it. The reducer the head and shoulders is included in the will bleach away the negative until at last scene, the background fading away to dead nothing is left but clear celluloid. As you black. have pulled the film out of the solution A piece of paper with two holes in it (Fig. gradually, and at a steady rate, the change 3) placed -over the iris will give you the on the screen will also be gradual until the effect of binoculars, used to indicate that screen goes black. If the film is pulled out the scene being photographed is very far too rapidly and all the emulsion is not away, although you are really quite close bleached away from the end, it can be im- to it. mersed again and pulled out a little faster TRICKS WITH A DUPLICATOR this time. After the bleaching is finished DUPLICATOR' (Fig. 4) slipped the film must be thoroughly washed and " over the lens or the vignetter will dried before it is printed. If two pieces enable you to make people disappear in the of negative film so treated are overlapped center of the picture. They simply vanish in printing, a lap -dissolve will result. in mid-air. The stunt is to place your cam- The same effect of dissolving can be ob- era firmly on a tripod, lined up so that a tained with reversal positives by bleaching tree or post will be exactly in the middle the necessary two feet and overlapping of. the scene. Then you take the scene with them, splicing at only one end. This end the lens covered and the people pass beyond should be the one that goes through the pro- thé tree. When the necessary footage has jector first. Care must be taken in rewind- been taken, you turn back in the same way ing to see that the loose end is carefully I told you a moment ago, but without mov- tucked in place or the film will buckle and ing the camera. Slip the changing bag over break. It is, at best, a poor substitute. the camera as it stands on the tripod and Fades cannot be made on reversal film in fasten it around the tripod head with a this way as the picture will fade out and strap or heavy rubber band. When the film Another "stunt" can be obtained by mounting leave a white screen, very objectionable to beginning a platform above a table and pointing the the eye. has been rethreaded at the of the camera downward, as illustrated above. scene turn the duplicator around so that the Photo courtesy First National Pictures. PEOPLE WALK BACK -WARDS first side of the film exposed is now cov- "Pr HERE is another trick that usually ered and the unused side is brought into use. street scenes from a second or third story 1 provokes a laugh. When taking a You can either run all the film off so that window. Also shoot them from a few inches scene, especially one with lots of action in the people disappear or you can let a few above the ground. Unusual shots of inter- it, hold the camera upside down. Then seconds elapse until they walk beyond the esting buildings may be made by standing a when the film is returned to you from the tree again. The effect will be either that few feet away from the base and pointing laboratory, cut out this section and reverse they disappear behind the tree, or that it the camera upward. If you saw "The it so the pictures are head up. When pro- takes them five or ten seconds to pass a tree Crowd" you will remember the opening jected the people in the scene will all move 'only six inches in diameter. scene, where the camera went up the side of backwards in a most comical way. This

DUPLICATOR

LL', ® At the right BLDG. '. , we see how it '- ',t -. r, Is possible to SE m ® obtain fou r ,g1 images on one %---- CORD frame with a - )I. I duplicator prepared with a L CAMERA! piece of black `"alll paper. FOUR IMAGES OF BLACK PAPER fhe illustration above shows three means of obtaining unusual pic- OBJECT ON ONE FIG. 5 PASTED OVER tures. Street scenes can be shot from the second or third story FRAME DUPLICATOR window. is pictures, FOUR EXPOSURES ON ONE FRAME a building and then into one of the windows. trick especially good for diving special and if you can have someone right along- "V HIS same duplicator with a slight This of course was done with appa- shooting in the normal way, ratus, but you can a shot from the side of you 1 change becomes a very effective piece take when the two are spliced together, the diver Jaabe. it into a shot from a of trick apparatus. Paste a piece of black and dissolve will jump into the water, and then amidst paper over it so that the opening is covered more normal angle. Try shooting vertic- reappear, feet first and re- in from a high building. All great splashing the same proportion that it originally cov- ally downward turn to the diving platform and resume the ered the lens. By turning it four times, the these things help to make your films more normal position. screen is divided in four sections and shows interesting. four pictures at the same "If you shoot a few feet of a scene with time. (Fig. 5). CHEMICALLY MADE FADE-OUTS When doing these tricks it is best to have no one in it and then stop our camera, place your view -finder marked off correspondingly YOU speak of fades and dissolves, Mr. some one in the scene and resume shooting, so that you can govern the action. This Jones. Is there any way I can do these the effect is rather startling. You can elabo- can be done by gluing four hairs across it with my camera except by using the iris?" rate on this by substituting someone every exactly bisecting the long and short dimen- "There is a device that will do this, or, few feet, until finally your audience will be sions. Your first few films might be poor if you use negative film, you can make chemi- lost in laughter. trickery but you will soon learn what allow- cal fades. To do this you make a weak "A lot of these tricks can be used in ances to make and the only way to do this solution of Farmer's Reducer. The weak title -making, and I want to show you some- is by trial and correction. solution allows a better control of the fade. thing about that the next time you come in." "You will find that unusual camera angles A fade is usually five seconds in length, Next month Jones and Blake will discuss will enhance the effect of your pictures. or two feet of sixteen millimeter film. Dip the construction and use of a title outfit. Watch the angles used Many money - saving in professional produc- ideas and short-cuts tions Sometimes it is in title making will be placed low, and again explained. it is high up. Put your p (Coot. on page 636) camera on the ground lllll 1111111111111111111111,1111111111111111111111111111111111111111. luv ®II ;I . ® a and run an automobile ®*! jÍI'. ; ' > T. >> r - 9» i At the left is an illus- over it. effect is The tration showing how startling to say the some startling effects - t, (i- - - , ( least. Get up on a ,,, 1 can be obtained by stepladder and look ( fli i shooting a few feet of a down on your friends, scene, and then stopping STOP J MAN TAKES STOP CAMERA HAVE GIRL STEP GIRL STEPS the camera; someone is rig up a scaffold on placed in the scene and TAKING POSITION MAN WALKS ON SCENE AND OFF SCENE the shooting is resumed. two ladders and look FEW FEET, (START TAKING down vertically on a (SHOOT SEVERAL FEET OFF SCENE SHOOT This can be elaborated OF THIS AND STOP) MOVIES AGAIN) on by substituting some- table of cards or of one every few feet. people eating. Shoot

www.americanradiohistory.com ] I) Science and Invention for November, 1928

A Simple Thermo -Cell Cigar Lighter and Ash Tray This thermo-cell can be made from ma- This gradually decreases until the tempera- a cigar lighter and ash tray for the autoist terials within the reach of any experimenter ture of the two carbons is the same. Even and radio owner, from odds and ends. the heat produced by the hand will cause a CARBON RODS deflection. Care must be taken not to heat the carbon above the boiling point of water, as the acid will sputter and may cause serious results. Howard James. COMBINED CIGAR LIGHTER AND ASH TRAY We publish the diagram of how to make This is a photograph of the completed product. It will be observed that this lighter is RESISTANCE both practical and neat. Its size can be compared with the battery clip.

OIL CAN The list of parts is given here. It includes BOWL one discarded oil can about two and one-half GALVANOMETER to -inches INSULATOR SOLDER three diameter, ten or twelve turns VERYDILUTE H2SO4 BUSHING of a 30 -ohm rheostat, a wooden handle of A simple thermo-cell can be made by means BRASS SCREW a discarded soldering iron, one inch of in- of two carbons and a solution of dilute sul- sulating tube taken from the same soldering phuric acid. Heat one of the carbons, plunge iron, and a strip of brass taken from an into solution and galvanometer registers. SPRING BRASS, old-fashioned jack, a few inches of buss and is much stronger than the thermo-couple, bar, one wood screw, one machine screw, giving fairly good voltage and relatively --WOOD SCREW solder and flexible wire. The construction high amperage. The strongest, as well as is given completely in the illustration. the simplest to make consists of two like OIL AN It will be observed from the illustration conductors immersed in a very dilute solu- NOZZLE that the lead going to one side of the re- tion of sulphuric acid. The electrodes are sistance passes through the oil can. This is best made of carbon, although some metals insulated from the can. The other battery are nearly as good. The carbon obtained WOODEN lead communicates with a piece of spring from an old dry cell will answer. The acid HANDLE brass, to the end of which is soldered a should be diluted about 60 to 1. The cell brass screw. When this screw is pressed, it is connected to a galvanometer or a milli - touches the side of the oil can, making con- voltmeter. TO BATTERY tact therewith and closes the circuit through To operate the cell remove one carbon the resistance. As will be seen, one end of from the acid and heat it to about 60° C. the resistance is soldered directly to the can. Here is a combined cigar lighter and ash tray Of course the oil can has to have its bottom Then plunge it into the acid, being careful easily constructed from an old oil can, some not to let it touch the other carbon. A wide wood and a resistance unit taken from a removed so cigarette can be brought in con- deflection on the galvanometer will be noted. radio rheostat. tact with the heated wire.-Thomas C. Leid. Operating Cost of Electric Appliances HOW many times have the majority them. What then? Now we must go to condition is at once made evident by exces- of us wondered what the cost per the meter itself, where, by remembering a sive arcing at the revolving part of the hour was on certain electrical ap- few figures we can determine the cost per motor called the armature and commutator. pliances which we use every day in hour of anything we might connect to a When the brushes are worn the motor our homes ? Now that we have radio "A socket. All meters have a constant which will not pull or start as it should until new and B" eliminators that we merely plug into denote the wattage registered for one revo- ones are installed, but before replacing them a light socket and sets that have no batteries lution of the disc, and by connecting to the be sure to look for weak brush springs. -how much do we pay for the convenience circuit any appliance and counting the disc It is rather a simple matter to replace and upkeep of these modern inventions? To revolutions for sixty seconds, we can easily brushes on fan motors, or those of this type, be sure, most electrical appliances, such as get the wattage for one minute. This figure as the motor need not be taken apart to do grills, percolators, toasters and curling irons is then multiplied by sixty, which gives us the work, the brushes (usually two) being are marked in watts on the maker's name- the total watt-hours of the appliance. For held in holes in the motor housing on op- plate and these are very easily figured out. instance, the 5 -ampere Sangamo meter's con- posite sides, the pressure of a spring hold- We know that one thousand watts equals stant is 5/24. This means that each revolu- ing them against the commutator. one kilowatt and all meters are read in kilo- tion of the disc is equal to 5/24th of a watt. If the brushes do not show much wear watt hours. If a toaster is marked 600 watts Now, if we connect a charger to the circuit try increasing the brush spring 'tension by and we pay ten cents a kilowatt for our cur- and count five revolutions of the disc in one stretching the springs a bit. we rent, the toaster, of course, costs us six cents minutes and multiply by the constant, get it is necessary Multiplied again by If to take the motor apart per hour to use. A cheaper rate for current the total of 25/34ths. to get at the brushes this should not be at- naturally lessens the expense of using the sixty equals sixty-two, which is the wattage The charger then tempted until you have scratched a mark on appliance in proportion. we are using per hour. both brush -holder housing and armature than a sixty - But what about it when an appliance is consumes only two watts more housing so re- of a cent per that you will be able to marked only in amperes, you ask? Simple watt lamp, or a cost of 6/10th assemble it just as it is taken apart. times voltage equals watts, hour to operate. The constant of the 5 - enough. Amperes A button -hook is a handy thing to hold the and if the appliance is marked five amperes ampere Wesinghouse meter is 1/3 and of usually the General Electric 3/10. We must, of brush springs out of the way while the and our house voltage is 110-which brushes are being removed, or replaced. is the case-we merely multiply them to- course, remember to turn off all other load gether and find that 550 watts is the result, from the circuit to get the true wattage of Small round brushes that are used in many or a cost of five and one-half cents per hour our appliances.-F..S. Saunders. small motors can easily be made out of flash- light battery carbons. To reduce them to to use on the ten -cent rate. KINKS ON REPAIRING ELECTRIC MOTORS One more question you throw back at me. the proper size fasten them in the chuck of Some eliminators and chargers have only Small electric motors occasion trouble a breast drill, or brace, and fasten this in a the output current or voltage marked on when the brushes become worn, and this vise, or hold it on the bench.-G. F. Stillwell.

www.americanradiohistory.com Science and Invention for November, 1928 611 Food Adulteration How to Detect Some Common Adulterants By WILLIAM LEMKIN, Ph.D.

LL foods, have learned, n a the digestive processes, and prove injurious the formation of lactic acid, the latter is number of essential elements known to the system, especially in the case of in- often neutralized by the use of baking soda, as nutrients, each of which per- valids and young children. or sodium bicarbonate. To detect the pres- forms a definite function in our In the testing of various foods for adulter- ence of this adulterant, a sample of milk body. In a recent issue of SCIENCE AND ants the home experi- INVENTION the writer outlined a series of menter has a highly elementary qualitative tests which the home fascinating field for cherhist may easily perform to detect the chemical research presence of these nutrients. But we are along truly practical sometimes confronted with the condition in lines. How often have ,I which certain articles of our diet are dis- you doubted the pur- IRON SPOON covered to contain substances other than the ity, wholesomeness or STIR WITH essential nutrient elements common to all high quality of a cer- MATCHSTIC NOISY SPLUTTERING our foods, and the unfortunate part is that tain food, such as WITH LITTLE OR these foreign ingredients, or adulterants, may milk, meat, butter, to- NO FOAM be harmful to your health. mato catsup and a host of other articles on TYPES OF ADULTERATION QUIET BOILING WITH your dinner table LARGE VOLUME OF FOAM BY adulteration is meant the altering of How many times have the normal composition of the food. It you wondered if a is accomplished in various ways: highly -colored jam or fruit extract reali \ GENUINE BUTTER RENOVATED BUTTER owed its brilliant hue to the natural fruit or LAVENDER berry ? Thanks to the Fig. 2. This easy test gives an unmistakable proof as to the genuineness COLORATION work of scores of pa- of your butter. The amount of foam tells the story. WATER AT tient analysts and food BOILING POINT chemists we have succeeded in standardiz- is evaporated down to dryness on a water ing the various tests to such an extent that bath, and the residue ignited to obtain the it merely requires a few simple manipula- ash. After cooling, add a drop or two of tions to unearth the cleverest and most deep- hydrochloric acid, and notice if there is any seated forms of adulteration practiced by un- effervescence, which would denote the pres- scrupulous food manufacturers and dealers ence of carbonates. today. Fig. 1. A simple test to prove the presence of formaldehyde as an adulterant in milk. "RENOVATED" BUTTER AND HOW PURE IS YOUR MILK? OLEOMARGARINE HE most nearly perfect of all our foods WHEN butter 1. By adding to the food some foreign has become old, rancid is milk. It is commonly adulterated by and unsalable, it may be "renovated." material to lower or injure its quality or the addition of water, or the remo,va. strength. and made to resemble the fresh article. The part of the cream. This fraud, however, process 2. By substitutir g, either in part or com- consists of melting the butter care- may be detected with conlparativ2 ease by fully, removing the curd and brine, blow- pletely, some inferior substance for the the use of a specially graduated hydrom- proper one. ing air through the mass to remove the dis- eter or lactometer, which measures the spe- agreeable odor, and then mixing with milk 3. By entirely removing a portion of the cific gravity of the milk, and records the dilu- valuable ingredient from the food. and churning. Some states require that this 4. By the addition of some artificial color- product should be marked `Renovated But- ing or flavoring material so as to conceal STRIP OF TURMERIC PAPER TURNS ter" when exposed for sale, while others its inferior quality, or to make the CHERRY -RED ON WARMING allow dealers to handle this form of butter food without restriction. look better than it really is, or simply more attractive. PIECE MEAT RUBBED Artificial butter, butterine or oleomar- WITH WATER AND garine is a common form of butter substi- 5. By mixing with the food some poison- THEN FILTERED, ous ingredient or any constituent that might tute which, although made from natural fats. be harmful to the consumer. and considered as perfectly good food, i. Adulteration then may be harmful, sometimes mixed with genuine butter, and. fraudu- as such, lent or accidental. Harm ful adulteration in- falls into the class of adulterants, cludes all those which are either in the sense that it lowers the nutritive value directly of the butter harmful by the addition of injurious sub- Fig. 3. Here is shown a test that will detect and constitutes a fraud. To stances, by the decomposed or unwholesome the presence of boric acid or borax in meat. listinguish between genuine butter and "reno- state of a part or the whole of the food, vated" butter, the simple boiling test is employed. Heat a sample in or by the dilution or extraction of some tion (not necessarily fraudulent). Another an iron spoon over nutrient part of the food, thus low flame, stirring constantly with a match- rendering it common adulteration is the treatment of stick. Boil less nutritious. Under fraudulent adultera- the milk the butter briskly, stirring thor- with various chemical preservatives, oughly. Genuine butter will boil quietly, tions are classed all those which do not especially in warm weather, to delay its directly or indirectly harm you with the production of considerable froth except in souring. Formaldehyde, or "formalin," is or foam, deceiving you, and making you pay more the which may even boil up over the substance frequently employed for this (Continued on page 654) than you would normally have paid. Acci- purpose. If you but consider that this chemi- dental is where the change was not made on cal is one of the chief ingredients of em- purpose. balming fluid, you can realize the grave Although most forms of food adulteration danger in its use for preserving the primary t,l arc harmless to your health, resulting only food of infants and invalids. in a raid on your pocket -book, there is one To test for formaldehyde, place a small common and outstanding type which might quantity of milk in a test tube. Add an BOIL WHITE CLOTH OR undoubtedly result in injury to your body. equal quantity of strong hydrochloric acid, YARN IN A MIXTURE OF That is the use of chemical preservatives in and a piece of iron alum about the size of THE JAM AND WATER certain classes of food. In recent years the a pinhead. Mix the liquids with a gentle, ro- practice of adding preservatives to food has tary motion to break up the curd. Place greatly decreased. These chemicals, such as the test tube in a beaker of water after boric acid and benzoate of sodium, preserve the water has been brought to the boiling the food by preventing the growth of bac- point, and leave it there for five minutes. teria. There may be difference of opinion When formaldehyde is present, there will in regard to the use of some of them, but appear a purplish or lavender coloration. If it seems perfectly reasonable that antiseptic this preservative is absent, the solution substances which will prevent the decay slowly turns brown. Fig. 4. If your fruit jam is colored with a of food will be likely also to interfere coal -tar dye, the piece of cloth will develop a with After milk has partly decomposed, with bright tint in this test. Natural colors are dull.

www.americanradiohistory.com 612 Science and Invention for November, 1928

dY.lJi^'l1Y'lllJ' f J' Ll1'llSiY'l3IJ`lJ''JZYiT/`./'vY9.^JZ2ZLII/'11^Y.. ... JL-Ji2ZJYL27III`ry.I{).. ..t.'q.. - I 7 1 ° tiY_.YfiRT. I\ i.Zúii-. 4i. . U f.:i w._E N I i ,:h.t.;K j.a.:'-iiii .i.iL N r M.tio ..' 41. .ti, JMr..- s; .. _4 ,:..Ñi y , . Tÿs s rp! Jew:- .` ; t. :..~ .,ï .' rx.. 1 W:/ '':.:wifSy i, /{C; IS; '.- M' .v Ìÿf_M",1i¿ ; 1 ..^ÿ Qi 1 ì Ç..' ::D,ti:S\1Ki."?Sr..'.e.\ ;.:';'-`_ .-r_q.:S._.a--rPs,nZrrs-1 J/'lJ'l1'1'JL-l-¡i/Y'l1LTZ-.ZS2LYrZ- , u 1.R/'NLR,rv'-Y./'l.'L-.l'J'lllllJ'.Y.r.rlrJ"lJ :..7 Building an Outboard Motor Hydroplane Little Boat is Eleven Feet Long and of the Simplest Construction. With Suitable Motor, Speeds in Excess of Twenty-five Miles an Hour are Quite Possible. By W. F. CROSBY THE advent of the outboard marine but may be built up of two each if wood of to take the forward ends of these chine motor has opened up an entirely new the proper width cannot be secured. The pieces and after screwing one side fast, the field for small, light race boats, boats maximum width is twelve inches. One edge two chines may be bent in slightly and that can be made for an extremely of one of these planks should be made per- wired together so that the other chine piece mall sum of money, are relatively safe and fectly straight, and from this the right-angle can be screwed fast. When secure, the wire is taken off. This stem block should now be raised to its proper height, so that the The picture at the left upper edge will come in a straight line with shows the appearance of frames 1 and 2. By nailing a piece to the the outboard motor back of this block and also to the floor, speedboat here described when it is skimming it will be possible to hold it securely in along at a good rate of place. Side braces might also help matters. speed. The Boat rides Be sure that your chine pieces run in fair very high in the water, as will be seen, and to the stem block. quite a little skill is re- The side planks can now go on. Start quired in maneuvering in by fastening them into a groove at the the craft. stein block, using heavy brass screws for ,,,,,,,,,,,,,,,,,,1,,,,,,,1. I, ,,,,,,I,.1,,,t 11",. the work, and then bend them gradually, one at a time, until you are able to screw are capable of speeds sometimes in excess lines representing the spacing of the frames them fast to the first frame. Go on back, of thirty miles an hour-a real thrill on the may be laid in. The length of each plank one frame at a time, screwing fast first water. "Flipper" is such a boat. She is should be about twelve feet, to allow for the one side and then the other, until you reach eleven feet long and fifty-five inches wide at bend and to allow for trimming off at the the third frame. The transom or stern is, the widest point. Flat bottomed, straight ends. From the top drawing in the larger of course, all one piece, made to the dimen- sides, she is easy to make and anyone who group it is now an easy matter to lay off sions as shown, and this should be in place is at all familiar with a saw, hammer and the distances, 12 inches, 11/ inches, 11% on the floor. The edges of the planking plane should have no difficulty in putting her inches and 111/2 inches at each of these will overhang the edges of the stern but together in a week's time at the outside. frame lines. The other edge is now trimmed before you set this member up, notice that The sides are brought in at the bow and down with a plane so that it is a line passing it is on a slight slant. The upper edge is the bottom comes up to form sort of a through each of these dimensions. The un- 2 feet 9 inches from frame 3, but the lower "sled -nose," which will permit her to rise up derside of this plank from station 0 to 1 edge is one inch less. The bottom should be on the surface and skitter along with the is a slowly developing curve which may be cut at the proper bevel so that the bottom best of them. There is no steam bending in easily planed down. It should fair into the planking, when we come to it, will be laid her construction and the slight bends in the rest of the lower line. When one plank is up flush against the wood of the transom. sides and bottom may be worked easily from complete, the one for the other side should The side planking is now complete on both ordinary lumber of the proper thickness. be marked dut and then cut down until it sides. It is screw fastened to the frames BUILDING THE FRAMES is exactly the same size and shape. and along the chine pieces, making a rigid We now turn back to the frames. Here structure which will now make it possible N the detail drawing, at the top, will be we have the one inch square notches cut to unfasten the frames from the floor and found the complete dimensions, and the into the lower corners for the chine piece turn the boat over. However, it would be first thing to do is to make full-sized draw- and this should now be fitted and screwed better to first put in the clamps along each ings of the sections, or frames. With an fast to each frame. The under side of the side up under the top edge of each frame. ordinary six-foot rule and a square of some stem piece or block should be chiselled out These clamps are of light material, V inch kind, these dimensions should be drawn directly on a fairly smooth floor. When the material for the frame is ready, it may be laid on these full-sized sections, one section at a time, and the boards screwed together by the corner brackets at exactly the proper angles for the bottom and sides. A temporary piece should be nailed across the top to hold the sides securely until the planking is in place. There are four of these frames and they are spaced exactly two feet nine inches apart. The bottom is a perfectly straight line, and the frames may be temporarily nailed down to the floor at their proper spacing, after notches for the chine have been cut at the lower corners. The next step is to get out the stem block. This may be a piece of oak or other hard wood about six inches square and roughly tapered to about the shape shown in the perspective drawing. It may be built up from several thicknesses of wood. The planking is fitted into a notch around the edge of this piece so that the surface, when finished, will be smooth. SIDE PLANKS WE will now lay this piece aside and The drawing above shows the general assembly of the outboard motor speedboat described in the proceed with the side planks. These present article. The seams are covered with wooden battens as shown, and detailed instructions may be made from one piece (on each side), are given in the article for cutting and assembling the various wooden members.

www.americanradiohistory.com Science and Invention for November, 1928 613

by PA inches spruce and should be pushed be necessary to use narrower planks, de- In operation, the weight of the motor being forward, and cut to exactly the right length pending upon the stock of the local lumber way in the stern, it is necessary that the so that onu. end. will butt up against the yard. operator be in a reclining position usually stem block and the other inside the tran- Start in by getting this data correct and pretty well up toward the middle of the som, taking in the bend of the side. It will then cut out the notch for each seam bat- boat as shown in one of the drawings. The ;be necessary to remove the temporary cross ten so that it is a nice fit. A single screw steering may be accomplished by a long 'pieces across the frames before these clamps can be screwed into place. They are fastened to the stein block and to each frame, as shown, and Finally to the transom. THE TRANSOM THE transom, since it carries the load of the motor should be somewhat heavier than anything else in the boat and for this reason it is advisable to have it about l'A inches thick and made of oak or mahogany. Where the clamps come to the transom, small natural wood knees are screw fastened to the clamps and to the transom in such a way that the entire structure is extremely Chine'- 1 rigid. P/ank' \ Frame We can now turn the boat over and begin Chime work on the bottom. Here, in order to Detail of stem block An upside down rien/ to make a tight job, it is necessary to resort showino how it is notched .show de%i/s of bo/torn to what is known as seam batten construc- out far' ,o/an/cs and chine ... tion. In other words, each seam or "crack" where the edges of two planks come to- The details of assembly are shown at some length in the illustration herewith. The picture at gether, is backed up by a light strip, fastened the left shows how the plank and chines are fitted to the stern block. to each by screws and made tight enough to keep the water out. Sometimes, marine glue through seam hatten and into the frame tiller arranged on the engine or by a small is put on the under side of the seam batten will hold it securely in place. steering wheel just under the canvas deck so that when it is tightly fastened down, the glue will make an absolutely leak -proof PUTTING BOTTOM ON KEEL CONSTRUCTION joint. THE bottom of the boat has a fin keel are shown in the WHEN this work is complete, take a These seam battens perfectly straight edged piece of the to prevent side slipping on the corners. various sections. The one forming the keel This keel is ,made: up of a piece of twelve the others and each bottom planking and lay it on so that one is slightly heavier than edge exactly halves the center batten or keel. or fourteen gauge galvanized steel or brass is notched into the under side of the frame plate, with one edge bent over and drilled on the It should be fastened to the under side of so that the planking, when it goes be easily with a number of holes to take screws by up flush against the frame the stem first so that the bend may bottom, will fit made. Then proceed to fasten it down to which it is f astened to the center of the boat and battens. The planks, like the sides, 1, 2, 3 the stern in turn, at a point just a little forward of frame 2. and aft and there should be a seam frame number and run for until it is fastened by about three screws This keel should be about a foot deep and hatten at each joint. These battens are to each of the a foot fore and aft at the upper edge, slightly equally spaced out from the center one at to each frame. It is screwed side seam battens by screws, through the tapered. The after edge of the keel should the keel and run from the inside of the at he just about even with frame 2, thus making the chine piece. The center planking and into the batten, arranged transom to one inch to make the job the rest of it come forward in the proper goes to the underside of the stem block, intervals of about one clone work properly, location. where it should be notched into place and tight. If you have the screwed down. Six planks are the edge of this plank, away from the There are all kinds of engines available securely the next such boats and of course the larger the shown on the bottom of the boat in the center batten, will exactly halve for but if you can get wider planks, seam batten out toward the chine and it motor the more speed obtained. However, drawing, is we you may reduce this number. It may also is screwed to this member just as to the "Flipper" a rather small craft and keel batten. The edge of the plank, toward should not overload her with a great big the chine and after it is screwed clown, may motor. One of the ordinary two -cylinder be treated with a little marine glue and the motors will be just about right. next plank, pushed securely up against it If you can't swim, don't take a boat of and screwed down in exactly the same man- this sort away from the dock because when ner. Plank after plank follows until the at high speed things are apt to happen entire bottom is covered and securely screwed quickly if you bump into the swell of some to frames and battens. The edge is, of other boat at the wrong angle. The boat, course, screwed to the chine piece and the under ordinary conditions, is stable enough, excess wood of the sides or bottom is planed but with all the weight out of water at high off to the proper line. speed, a bump at the right spot will turn Each of the planks in the side and the her over quickly. Any speed boat is subject bottom should be in one full length through- to this. Unless "Flipper" is greatly over- out the boat. Lumber of this length is easy powered, she will make a fast little hydro- to get and a joint will make a small boat plane, safe enough for all ordinary work weak and it will surely develop a leak. The and the next best thing to flying through bottoms of these little hydroplanes are sub- the air. jected to heavy strains and they must be When powered with a suitable outboard made strong enough to take these. The seam motor, the boat described here is capable of batten construction does much toward aid- making a speed of thirty miles an hour. ing this condition. The craft is relatively safe due to its flat Each joint should be treated with marine bottom and straight sides, which also en- glue and the entire hull sandpapered as able it to be constructed easily. There is no smooth as possible. Be sure that the heads steam bending needed and the curved por- of all screws are countersunk flush with tions can be easily made from ordinary lum- Uamp 7z ï /7z *Jpruce the surface of the wood and that the slots ber. The bottom of the boat has a thin ! upr,e+ urnes 7z /7z ea*. fore and aft. This keel so that it will not slip sideways when ,Bencke/s % öak in the screw heads run ; Lowerfel'e7eS%Ñ2áak will prevent some friction and everything taking corners. It is important to treat each Sean,//en5 /Ix/k "J,oruce smooth as you joint marine glue, so that they will be ' A Len/çrlM//en»xz öak counts. Get that bottom as with got/om7z['edar possibly can and after you have given her water -tight. The smoother the surface of 7 ; Sde iecedar_. of paint, proceed to sandpaper it the boat is made, the faster it will go. The Chine/"x/"sPruce`. a coat again, after the paint is dry. The smoother heads of all the screws should be counter- a'1!mA':'. you can get it the faster she will go. The sunk, and the surface sandpapered, after ''9/1 fas/enings to 'e brass so infers, nk head Scren's inside, too, should be painted to preserve the which it is given a coat of paint. When Construe/ion section showing the first sizes of materra/s wood and the forward end may be covered coat is dry, it is again sandpapered over for about half the boat's length by a and repainted. A few slats tacked on the light canvas deck supported on light wooden floor will provide a suitable seat for the A sectional view of the speedboat is shown in frames. A few slats should be tacked down operator. Steering may be done with a long the drawing above, as well as a top view with to the frames to make a floor so that you tiller, as shown in the illustration, or a small dimensions, and. also the sizes of the various frames. won't sit directly on the bottom of the boat. wheel may be arranged under the desk.

www.americanradiohistory.com 1T Science and Invention for November, 1928 Wood Turning for the Amateur By H. L. WEATHERBY Article No. 5 of a Series FRENCH POLISHING AND OTHER FINISHING

AST month we promised that in this It should be made of straight grained it should fit loosely, and glued back together. article we would take up some of hickory. If carefully done, the finished article will the points of French polishing; and The gavel differs in no respect from the be a credit to any craftsman. while we are discussing that we will mallets made previously and we suggest And last, we have the match box, which also consider very briefly other methods used black walnut, mahogany, or maple for this. will he welcome on any smoker's table. in finishing turned work. Having turned one or more of these ar- Several small articles, most of which ticles and sanded them carefully with "o" should be finished natural are shown in the or "oo" sandpaper preparatory to finishing, drawings. Only very general dimensions we are ready for the application of the are given and where desired the design can, French polish. It is well to keep in mind of course, be changed to suit the individual. that vibration is ruinous to a good finish, There is no particular sequence used; for so do not turn the ends down smaller than if previous exercises have been followed about %" or ',4", and then to further avoid carefully the readers of these articles should vibration operate the lathe when it is set by now have a very good foundation for all in motion for polishing, at a medium speed. future work in the art of wood -turning, and from now on we will deal with the MATERIALS REQUIRED FOR POLISHING kinks and the frills; rather than the regular WF will need the following materials turning ; which simply calls for practice and for the polishing. A wide -mouthed more practice for the development of skill. bottle holding shellac ; a similar bottle but For those of an athletic turn of mind, the The polish is applied by holding the pad with smaller mouth for alcohol ; a filled oil Indian club and the dumb -bell will be of lightly against the revolving piece of work. can with a spout ; some cotton waste; a small interest. They are of a size to he of cor- quantity of rotten stone, and a piece of rect weight if made of hard wood; maple Next we offer the tie or towel ring. cheese cloth. For filling open -grained woods preferred. On the dumb -bell a little addi- It really calls for some rather expert turn- the ordinary methods for filling are used tional practice in turning a sphere is to be ing, and offers something new, in the turn- and fillers will be needed where such woods had, but it will not prove to be so difficult ing of the rii.gs, which is done by the aid are used. Close -grained woods will prove as turning the croquet balls were last month. of a chuck. The drawings illustrate the to be more satisfactory for beginner's use. The vise handle should be of interest steps in the turning of this ring, while the The wood may be stained before polishing. to everyone in a home workshop, for vise standard on which it is mounted may be For beginning operations we make a small handles are forever breaking. The con- turned either between spindles or on a face- pad of the cotton waste wrapped about with struction is plainly illustrated -and naturally plate. The ring, after it is turned and pol- cheese cloth. Now hold the pad over the 't will be nearly as good a handle if it does ished, should be split very carefully, placed mouth of the shellac bottle and tip the not receive a French polish-hurt not quite. through the hole on the standard in which (Confirmed on page 667)

4 - - INDIAN CLUB - DUMB BELL _- .

9.. S"

-.-DEAD CENTER ,; END. BORE- HOLE VISE HANDLE STEPS /N TURN/NG ARE SHOWN. THE LOOSE KNOB GAVEL /8 I8 r SHOO!.D BE GLUED ON WHEN HANDLE /S PLACED 8 THE KNOB 2" 8" fATURN T THIS ENO LIKE OPPOSITETHE III/ o BE URE OF A TIGHT F WOOD TURN/NG FOR THE AMATEUR

FASTEN TO THE WALL WITH SCREWS.

BORE INSIDE O,w THE\ LATHE TO DES/REO OEPTH.

TESTETSAKEN ING TIE OR TOWEL R/NG THE RING BE CUT TIN NTWO THEPIECES MATCH BOX 3"oa AND GLUED BACK TOGETHER /N POSITION.

The above illustration shows a number of small articles which can easily the design can be changed to , suit the individual. All can be finished be turned in a lathe. Only general dimensions are given and where desired with French polish, as described with full details in the text.

www.americanradiohistory.com Science and Invention for November, 1928 615

..JSlI' llld...... , -'. rll-I"d^.J-J`slflYlll

ARTICLES OF INTEREST TO EVERYONE \.0 TIIßEE USEFUL IDEAS MILLING WITH A LATHE A MYSTERY TOP SENSITIVE BALANCE The outfit described here may be used to T h e illustration shows demonstrate that a piece of saft iron is some- 6" how the two times repelled by a magnet. This top con- vises of the sists of a soft iron or a soft steel disc about bench drill NEEDLES type are ar- 4 inches in diameter, 1/16 inch thick or less, ranged and drilled at its center and clamped to a 6- or 8 - fastened to a inch bolt by two nuts, as shown. lower SMALL The NAILS OR short heavy SOLDERED end of the bolt is ground to a point. GLUE "A' IS THE FULCRUM length of "B" DOESN'T SUP. When about to demonstrate, show the au- STEEL angle iron. PORT THE BEAM, WIRE dience that a magnet attracts the disc in the BUT KEEPS THE usual way, then spin the top on a glass plate CENTER ARMS WITHIN A and bring the magnet near to the disc. The KNIFE FEW DEGREES OF edge of the disc will be repelled and the top HORIZONTAL will incline noticeably. This action is due to the eddy currents generated in the disc, the magnetic field due to this current is in R SPACED '' opposition to the field of the INTO 16TH'S l) magnet, with the result that /CHAMFER the iron disc is repelled by the <<.3.__,__-If 4 magnet-hut only while it 6." spins !-C. A. Oldroyd. IWO STRIPS OF TIN SOLDERED IN FORM PAN OF SIDE CROSS The illustration below shows the DETAILS VIEW surprising action which takes place WATCH GLASS when a magnet is brought SOLDERED near the rotating disc. PLACED ON CROSS

The construction is illustrated in detail in the front and side views shown above. PERMANENT 3/, OR '/,"60LS MAGNET The tange is cut off of the large drill vise, The needle at A is the fulcrum, the needle and it is further altered to perform as the NUT B functions to prevent the balance arm from vertical feed. The small drill vise is mounted rocking too far from the normal horizontal on the movable jaw and holds the work be- position. pointer may NUT SOFT IRON DISe. The "center knife" or ing milled. The large vise frame is now '/fi THICK AND he made from a thin steel wire hammered screwed to a short heavy length of angle - 4" IN DIAMETER into a long thin tapered shape, as illustrated. iron. The handwheel attached to the lead After being shaped, the pointer may be FILE OR GRIND' screw might well be an old pulley with the PLATE GLASS heated to a red heat ff END TO POINT and cooled suddenly, groove turned off ; a short length of cylin- thereby hardening it. If the needle is too drical rod serves as a handle. Joseph brittle it should be polished and reheated Pignone. evenly to a light blue color.-Stanley Oliver. Gasolene Torch Useful in Laboratory

An alloy is being melted by the A similar operation is being con - The torch is admirably suited to It may be used for making flame torch in an ordinary crucible. ducted here with a sand crucible. glass working in the laboratory. tests also.-F. R. Moore.

www.americanradiohistory.com 616 Science and Invention for Noventber, 192d

E C d PES SZ FORMULAS Edíted by S. Gernsback

SAVING RUBBER HEELS RESTORING FADED PHOTO- ROLLING LAMP GRAPHS Three boles The useful It occasionally happens that one has a may be life of rubber drilled in heels may be photograph of an old friend or relative, with the base of considerably which he is loath to part, but which has be- the floor - extended by 1 amp, a s placing the come yellow and faded with age. shown in left heel on The simple method described in this ar- the illustra- the right shoe ticle will restore to such prints much of their tion, and and the right former color and brilliancy, provided of three casters heel on the inserted. left shoe, course that the directions are carefully and This will when one faithfully followed. provide a side of the First of all make the two following solu- lamp which heel is almost can be easily worn out, as tions: moved at shown in the illustration. This exchange of A :-Distilled water 5000 parts will, with heels should, of course, be made before any part Tungstate 100 parts very little of the heel is completely worn down.-D. S. Sodium effort, a n d Jenkins. B:-Distilled water 400 parts will not have to be Carbonate of lime (pure) 4 parts lifted. This Chloride of Lime 1 part scheme is Gold and Sodium Chloride 4 parts particularly useful when MAGNETIC COMPASS applied t o All parts by weight. exception- Make the solutions in the order given, ally heavy The experi- floor - lamps. menter very and keep solution B in a glass stoppered If the stems often has bottle of dark color, preferably yellow, and of the cas- use for a let it stand for twenty-four hours, at the ters project compass, but above the many of the end of which time filter into another similar base, they commercial bottle. may be eas- compasses Remove the prints from their mounts ily cut down have very in a bath composed with a hack- weak m a g- and wash well, and place saw. - Sid- nets and of 150 parts of "A" to 6 of "B," in which ney Lang. poor bear- they are to be left for about ten minutes, ings, with the result during which time they will gradually as- PLUG CONNECTOR that they sume a purple tone, when they are washed SPARK a r e easily for half an hour in running water, and then Many "B" demag- fixed in a mixture of 150 parts of "A" and batteries a r e netized and provided with become useless. A compass constructed as shown 15 parts of Sodium Hyposulphite, until all Fahnestock here can hardly be improved upon for rugged- trace of .yellow has disappeared. This may clip s. These ness. This compass will, of course, require a take from a few minutes to six or seven clips are very longer time to come to equilibrium than the usual useful and type.-F. Schmulowitz. hours depending on the condition of the one excellent prints. service to After the prints have attained their proper which they in running for may be put is color they are washed water illustrated a t several hours and then mounted in the usual the left. The LEATHER SAVING manner. wires may be Instead o f It is the writers advice to make the first removed with- throwing few experiments with prints that are held out using worn - o u t pliers. - Joe leather in no particular esteem, until the knack Kulyk. immedi-goods away of doing it is obtained-Contributed by Ivan ately, it llaittcnden, would be advisable to cut a circu- PREVENTING SPLIT HANDLES lar or ellip- PURIFYING WATER tical piece from the One drop of ordinary tincture of iodine article as large as mixed with a quart of contaminated water possible. renders it safe for drinking purposes in This piece 30 minutes. This method, while not rec- o f leather ommended for general use, will be found can be cut in such a way that a leather thong ten feet long very handy for campers or travelers who or longer may be secured. Pieces of flexible may have occasion to use water suspected Any pipe fitting with internal threads may be leather are very handy at times, and leather of containing dangerous impurities. screwed over the end of screw -driver or chisel strips can be made into such things as bridles, handle and cut off so as to leave the ring shown. belts, quirts, etc.-John Matson. -H. L. Ketcham. SEAL AND LABEL GUMS REPAIRED COMB A good recipe for gumming seals, stamps, Many times SPARE TIRE COVER labels, etc., is as follows: a comb is Mix 5 ounces of water, 1 ounce acetic acid, broken, An old in- leaving a ner tube and 1 ounce grain alcohol (ethyl alcohol). jagged, un- may be slit Dissolve 2 ounces of Dextrin in the mixture, sightly edge. with a pair apply to the paper and allow to dry thor- This condi- of shears as tion can be illustrated, oughly. easily elimi- the valve Another recipe not requiring grain alco- nated by fil- removed, hol is the following : ing down and may the jagged be Dissolve 1 ounce gum arabic (or dextrin) portion and then in a little water, add 4 ounces of sugar and finishing slipped with fine over the 1 ounce of starch. Boil on a water bath sandpaper. tire. - K. until the starch is dissolved and thin down -Sidney Koochi. with water. Lang.

www.americanradiohistory.com Science and Invention for November, 1928 617 Readers Forum SCIENCE AND INVENTION desires to hear from its readers. It solicits caustic or not. So if you have anything to say, this is the place to say it. comments of general scientific interest, and will appreciate opinions on Please limit your letters to 500 words or less, and address your letters to science subjects. 'Ihe arguments pro and con will be aired on this page. Editor-The Readers Forum, c'o Science and Invention Magazine, 230 Fifth This magazine also relishes criticisms, and will present them, whether Avenue, New York City.

YES IT IS! Bred. y -ou will reach the same result, and you can vast population, mean nothing. Had you assem- search through of the United bled 100 people fifty years ago and SCIENCE AND INVENTION: the entire population asked them Editor, States or the whole world with the sanie average whether they thought would ever be able Following are twC statements from two different they to you that to fly like a bird roads newspapers: result. The thought may then occur or run along the with is possibly may be horseless carriages, laughed airplane is a miracle, because it scotis where there much smoke, there they would have at "The you. Ninety-nine out of hundred would have at the law of grasitation. Incidentally, the real some fire. one Now death -bed phenomena. Millions of said "impossible." Those ninety-nine out of one miracle will not he the flying machine that makes take presence of spirit hundred might have been suffering from halluci- flight of a week's duration, but one that dying persons have asserted the a non-stop Were persons all subject to nations, and then again perhaps not. The fact stand still ill the air, even if only for an relatives. these dying will -minded a have seen hour. (This discovery will cause unpleasant illusions or was there one single clear that vast maority believe they a for Newton if he hears about it in the observer ill the vahole vast multitude? Now con- spirit does not mean to say that they have actu- moments sider hypnotic phenomena. Scientists babble too ally seen it. The mind plays peculiar tricks and other world.") and ignore other if you close your eyes and only care to visualize "Some day we nay gaze aloft and see all air- much about hypnotic sugge,stiou, phenomena. investigators have often as- a scene, you will see it in front of you rather plane suspended it the air, waiting for London Occult a deeply hypnotized person can be made strongly. You can increase the intensity or the and Paris to )eueath." serted that pass to in places and bring back a brilliancy of such an image to such an extent with, .ve are aware of (disregarding travel spirit to far To begin report. Have scientists carefully checked up it will actually appear present. Such is the several minor motimis) three principal motions with the that this statement? The is they have not. here case in dreams and you have no doubt awakened regard to our earth. First, our own 'island uni- answer is an opportunity for you to do some further in- on many an occasion and found it difficult in- verse" (which is one of the many that go to vestigating if you like. deed to believe that you were not dreaming. make up the whole universe) is moving towards the TAcon LEvy, Inasmuch as no one can define a spirit, it Vega, at the rate of many thousands of miles star Chicago, Ill. would be impossible for a person to say whether Secondi z, the earth is making a yearly per hour. they had seen it or not. If a person can see a voyage round the run at the rate of about 70,000 hour. Thirdly, the earth is revolving spirit, it can be photographed, and there is no miles per conclusive proof that a spirit photograph has round its own axis at the rate of about 1,000 miles quotations suggest, ever been taken. The camera will record things per hour. Now as the preceding NC which even the human eye cannot perceive. Infra- go up in an airplane, stand still, let Men if we cottld red and ultra-violet rays, invisible to the eye, we would in effect 1w the world go by -Ieneath, can be photographed. traveling at the speed of 1.000 miles per hour. IN OUR seems very logical: to do There is an old adage that where there is That at first gla-ace NOVEMBER ISSUE: smoke, there possibly may be some fire. You that, however, would require the nullification of AT have quoted this adage and inserted anothe gravity. THE WORLD word The fact that be nullified? And supposing BAY, by B. and Geo. probability-the "possible." But can gravity ninety-nine people out of one hundred smell it could be, wouldn't it require great energy to C. Wallis. (A Serial In Two isn't apparently what the gasoline Parts) Part I. Interplane- smoke does not necessarily indicate that the fire do that, and 'hat tary stories always seem to is present. An examination would disclose this. engine does at the present time.? We know every please our readers. The ap- have to be conducted along with the earth as it rotates; The examination would body is carried plication of the fourth dimension, in this who is in fires. The every free molecule of gas on by one experienced locating that this applies to story, enables the travelers to make the same is true of spiritual phenomena. surface, to a heavy body, such as all journey to the moon and back and around thing the earth's True, there are of dying persons that in a free moving gaseous the earth in an astoundingly short time. millions airplane, immersed have asserted of spirit relatives, as well in fact that neither matter or THE ANANIAS GLAND, by W. Alex- the presence medium no more a dream. The mind for call escape the ander. What determines the extent of but this is than energy (light rays example) our It might very well be in a be- Anything standing still in the truthfulness? travels very rapidly dream and either power of gravity. glandular action of some kind. Mr. Alex- comes futuristic or retrogrades back over the a small fixed circle, is not air, or traveling in ander has given us several unusual stories of As a matter of fact, illu- the world roll by" beneath, but is being in scenes childhood. "letting of psychological import, and this very sions frequently occur at the time of death which along wit] it at a speed of about 1,000 short story he cleverly works up an idea carried make the person dying act like a two -year -old, hour, as well as when it pursues a definite of extreme interest. miles per or a -old child. of direction. THE PSYCHOPHONIC NURSE, by David three -year course H. M.D. Instead of contenting Appertaining to haunted houses, we would ad- point to a recent prophesy Keller, In concluding, I might himself with the conception of new me- vise that every haunted house which has ever by a Canadian av_atiou expert, that the day is not chanical labor-saving devices-generally at a been investigated was found "not haunted." This far distant when an airplane may travel involved in the human scheme of life- people And such in spite of the fact that thousands of had 'velocity of 1,000 miles per hour. when Dr. Keller always goes further. He gives visited them. a day comes, isn't that in effect accomplishing as us, in a perfectly natural manner, the ultimate psychological effect of his me- Concerning your hypnotic effect, we would say much as is prothesied ill the above quotations, this writer has personally conducted ill a manner? chanical innovation or innovations, on that the only different being. Though de- of 11ENR1 the human he never experiment hundreds times. Never on check. Jolts MEREDITH, stroys-or even temporarily puts out of Ing it up, has the experiment proven accurate. .New Conn. Haven, commission-his newly developed appa- Of course, there were times where a fair amount is being nullified to a very slight (Gravity ratus, we are glad, when we finish the of accuracy was obtained. was for this reason extent by the airplane. Anything which does story, that we are still a little ahead of It the invention. that this writer was heartened to try further not continue to fall down toward the center of along line. Subsequent re- is naturally either nullifying or sus- THE EYE OF THE VULTURE, by Wal- experimenting this the earth ter Kateley. It is an established fact by sults indicated that the average accuracies in pending gravity for the length of time that it this time that the human eye is limited comparison with the inaccuracies was very low, Is acting. in its vision of the colors of the spec- even less than that which would be obtained by Of course, your reasoning is correct. The trum, just as the ear is limited in its ordinary guessing. gravitational influence holds the molecules of range of sound appreciation. And just as hope we have gases comprising the earth's atmosphere close the power of vision varies among people, By all these statements we that so it must differ much more drastically not tried to change your idea of a life after to the earth and for that reason an airplane death. Even though this is not de!ïnitely proven, would have to travel at a speed of 1,000 miles from that of animals, birds, insects, etc. A bird, for instance, may not see all we the thought is beautiful to behold.-EDITOR.) an hour or more in order to counteract the do; on the other hand, many things within motion of the atmosphere. Of course, it was the bird's visual range, may be completely foolish for the newspaper to state that all a out of ours. EARTH ONCE PART OF SUN? plane would have to do would be to remain sta- Editor, SCIENCE AND INVENTION: pass tionary and let the earth beneath. From Do y -ou think it possible that this earth we out in space that plane might be stationary with are living on today was at one time part of the reference to the earth's axial motion, but actu- (We are not trying to argue against a possible crust that may have been on the sun? ally, it would lave to continue to travel at a belief in life after death. Religion is not entered I think perhaps it is possible. At the beginning speed equivalen: to that of the peripheral rota- into in the discussion of our spiritualistic investi- of the solar universe I think this is what happened. tion at the point where it rose. gations. You may believe in life after death and This is my idea of how this world came into Did you ever stop to consider that when gravi- we may hold that there is no such thing. On the existence. tation is annulled over any spot on this earth, other hand, most of us adhere to the viewpoint After being cast off by the sun the world was the effect will cause the atmosphere to rise that something must take place in this transition thrown many millions of miles from the stun. As upward and produce a terrific hurricane at the and something must happen to that illusive quan- the sun's crust was covered by ice and water, this point where the gravity nullifier is in opera- tity called the soul. The body does not change world took part of it along with it. A rotary motion tion ?-EDITOR.) in any respect whatsoever, yet the greatest was also imparted to the world. Now as we know minds, the greatest mental powers are blotted that ally body that will conduct electricity when SPIRITUALISM AGAIN out when death takes possession of the body. rotated in an electrical field, a magnetic or attract- Editor, SCIENCE AND INVENTION: In accordance with the law of the conservation ing field is set up around it. So with the world, I have read your articles against false mediums of energy, nothing can be lost and nothing it is composed of elements of which the majority with interest and sympathy, but my belief in a life gained; therefore, this mental power is not lost, will conduct electricity. These elements being after death is Lot disturbed. Take the statistical but we no longer see it, we no longer feel its rotated in an electrically charged atmosphere, set phenomenon, fol example. If you assemble one presence or notice its effects on the vast multi- up a magnetic field around themselves and thereby hundred persons and inquire whether any of them tudes. Hence, we can rationally assume that are attracted toward the center of its axis. llave ever seen or heard a spirit, a percentage of this mental power goes somewhere, and for the Perhaps millions, even thousands of years after them will answer yes, with mathematical certainty. sake of the argument, we might hold that it the world was cast off it wandered around through If you then dismiss the first bunch as being sub- travels to another planet or to another state. space before it took up its orbit around the sun. ject to hallucinations and assemble another hull - Statistical calculations, when representative of a (Continued on page 653)

www.americanradiohistory.com 618 Science and Invention for November, 1928

Built and Described by the Staff How To Build The 5 &I TELEVISION RECEIVER

A slight adjustment of the rheostats and the picture comes in clearly. This. photo shows a complete television receiver connected to an ordinary radio set. The picture is seen in the cone.

TIIE front cover illustration shows find out whether the motor can be slowed the simple television receiver designed down to a steady speed of 450 r.p.m. If and built by the editorial staff. The A Television Receiver of the A.C. motor happens to be of the type accompanying photographs and draw- Simple Design, Built Around that has throw -out contact brushes, which ings show the appearance and the construc- open the starting winding after the motor tion details of the television receiver, the an Ordinary 16 -inch Electric has attained fairly high speed, you will prob- apparatus pictured having, of course, to be Fan Motor ably find this sort of motor unfit for tele- connected to the output of a suitable radio vision purposes. If the motor is of the universal A.C.-D.C. type, with commutator and ' receiving set. The ideal set for receiving television images from WRNY or other brushes, the armature being connected in stations, is, for the broadcast wavelength r.p.m. required for reception from the other series with the field, then you will find that of 326 meters, one comprising two or three stations broadcasting television. this motor can be regulated as to speed tages of tuned radio frequency, a detector very nicely by means of the series resist- If you have to select or use an alternat- diagram. and at least three stages of resistance - ing current fan motor, then you will have to ances shown in the accompany We coupled amplification. When a resistance - strongly recommend a universal type motor if you are going to purchase one, as these coupled amplifier is used, it will be found DISC best to use aboue 250 volts at least on the have been found to regulate well with re- last stage from either storage or dry "B" SIZE OF gard to the speed. batteries. A good "B" eliminator may be DIAPHRAGM used, but a special filter is usually neces- ,2 1'N OPENING MOUNTING THE DISC sary, to prevent "motor -boating" with a resistance -coupled amplifier. THE disc used in the television receiver here illustrated was a 48 -hole 16-inch MOTOR FIRST ESSENTIAL PROPER I Ì diameter bakelite disc of standard manufac- i I THE first requisite for building this tele- 48 ture. This disc may be mounted and se- vision receiver is a good 16 -inch fan %4ó 47 cured on a regular bushing provided with motor. If the television disc to be used ---47 o lock nuts supplied by the people who make (it should have 48 holes for reception from the disc. In the present case, however, the WRNY and 3XK ; also 1XAY and WLEX perforated disc was mounted on the brass of Boston ; and 24 holes for reception from END OF spider and hub which had originally car- WGY, 2XAD, and 2XAF, G. E. Co., Schen- VIEWING ried the fan blades. The blades were re- ectady), is quite light, a 12-inch fan motor HOOD moved from the legs of the spider and these may do the work. If you have direct cur- were then flattened out in a vise and checked rent in your laboratory or other location up on a lathe for alignment. A light cut where the apparatus is to be operated, then may be taken across the face of the spider you will have no trouble in controlling the legs in the lathe,, if one is handy. By speed of the motor down to the 450 r.p.m. The method of laying out the diaphragm open- drilling holes through the bakelite disc, it required for WRNY reception or the 900 ing is shown clearly by the above drawing. is readily secured to the spider by machine

www.americanradiohistory.com Science and Invc¡ilion for November, 1928 619

screws and: huts, or the holes in thè spider VIEWING HOOD AND LENS legs may be tapped .if the builder so desires. Care must be taken to see that the m HE viewing hood or visor shown on the disc rotates as perfectly as possible in both 1 machine herewith was built by cutting planes of rotation, that is, flatwise and edge- down a standard megaphone which can he wise; in other words, it must not wobble purchased in any sporting goods store. The and care must be taken to see that the heavy metal ring at the mouth of the mega- spiral is rotated in a true manner. These phone enabled the designers to secure it by two requisites are easily checked up by means of three spring brass clips, soldered means of a machinist's surface gauge, or to the brass front plate shown in the draw- else by making up a gauge from a nail ings. It can he snapped off whenever de- driven in a block of wood and holding this sired. One of the accompanying drawings near the disc as it is slowly rotated by shows how the size of the diaphragm plate hand. is determined, the rule here being that only one disc hole or perforation must be ex- NEON TUBE MOUNTING posed at a time. A thin piece of leaf cop- HE frame for supporting the neon tube per was used in the present case, from 1 behind the revolving television disc is which to cut the diaphragm opening, and simply constructed from light brass bar, this was sweated to the brass front plate of measuring about 1/16-inch by 5 -inch. Strap the instrument. A fairly strong lens, about iron may be used if the builder happens to This indicates the arrangement of the 2 inches in diameter, with a focal length have this stock on hand. No dimensions holes and the direction in which the of approximately 31% inches, was procured disc should rotate to receive tele- for the of the are given for the height of the frame as vision from station WRNY. purpose helping to enlarge many builders will want to use a different image. This lens was secured inside the size disc than the one we used, and so the megaphone viewing hood by placing three height of the frame and the dimensions of HINTS ON RECEPTION machine screws through the megaphone shell the metal composing it will depend upon WITH regard to the style of motor to and putting nuts on these, inside the shell. the diameter of the disc, of course. use this is best of the series type; This is probably one of the best ways to that is, with the armature and field wind- build Examination of the drawings herewith ing connected in series. Small induction the viewing visor for any size tele- will show that the neon lamp may be ro- motors can be used, but do not regulate vision receiver, as the visor can always he tated, so that the front plate inside the tube well in speed much below one-half their snapped off the machine when it is to be normal speed of 1750 r.p.m. If the picture moved to some may be placed exactly parallel with the per- image is observed and drifts toward the other location. forated television disc. This is easily ac- right, the motor is going too slow; if the complished by the simple expedient of using picture drifts to the left, it is going too STROBOSCOPE INDICATES CORRECT SPEED a standard vacuum tube socket having a fast. The editor has found it advisable to regulate the motor speed to a point con- OE hole in the center, or is known as the of the greatest problems the begin- what siderably above the desired value, and ner in one -hole mount. By passing a machine then to apply a piece of cardboard or a television reception will en- blotter against the surface of the disc to counter is that of checking the'éorrect speed. screw through the center of the socket and slow down the speed to the desired point. putting a nut on top of the bakelite Of course the average machinist or elec- shelf, D.C. motors will regulate very well with not the socket and neon tube can be rotated as the electrical rheostat arrangements shown trician will mind checking the speed in the circuit accompanying this article, frequently with an ordinary speed counter, required. Two sub -base brackets or sup- however. ports, available at any radio supply store, or possibly he -may be so fortunate as to are used in building the top of the super- own a.-tachömeter for the purpose. How- structure which carries the neon tube. Two ever, the average tachometer cannot be used well insulated with a small motor, as it takes too much wires lead from the vacuum power tube socket down to the base of the machine. the neon tube on your receiving set. from the motor, and therefore -slows testing the disc down not The connections to the socket for the faces the television is and you do know' where aver- The plate that disc you are age neon tube is to the plate terminal and the one.that.,has to be illuminated. In some at. to the diagonally opposite filament terminal. neon tubes.'fhei`e.is a large and small plate; The method of using the stroboscope prin..' This can be determined by experiment after the' large sclutye plate is the one that is to ciple, with the black line disc noted on the the machine is built, or else beforehand by face the television disc. front cover and in the present photographs,

In the diagram at the left, 1 indicates a separation of the wires leading to the socket 2, affixed to top plate 3, which in turn is mounted on the uprights 4, screwed fast to the motor by the screws which hold the case in place. The wires 5, lead down to binding posts 8, which connect with the ordinary receiving set. 9 is the standard switch on the fan motor which receives its current through plug 10. 11 is a control button, 12 the holes in the television disc, and 13, the cone.

Right: 1 indicates the cone; 2, the lens; 3, the disc; and 4, the stroboscopic pattern; 5, attachment plug; 6, control button; 7, vernier rheostat; 8, main motor control; 9, neon lamp control; and 10, leads to the receiving set.

www.americanradiohistory.com 620 Science and Invention for November, 1928

This disc can be cut out is struck on the edge of the table or across and glued to the center of a television disc. When the knee, and while vibrating, it is held a viewed with a fork few inches from the eyes and twisted, so having 128 vibra- that the revolving disc is observed in a tions per second, the pattern diagonal line passing under the corner of remains sta- the upper fork leg and over the corner of tionary a t the lower fork leg. This line of sight is 450 r.p.m. shown in one of the accompanying diagrams. While in most cases it will probably be found that the number of marks on the disc or else the vibrations of the tuning fork to be used will come out to an even figure, or at least that a suitable combination can be worked out for the speed desired, the calculation may show that an uneven number of marks will be required with any standard WITH WRNY fork. Here, instead of using a number of 128 2XAL radial black marks on the rotating disc, a 11111111\111111114.\ FORK (450 R.P.M.) spiral may be used and with this sort of design, any uneven number of convolutions such as 7%, 7-1/3, etc., may be employed. HOOK-UP OF APPARATUS 3XK WITH WLEX ONE of the accompanying diagrams 256 1XAY shows how the power clarostat (about FORK WCFL 150 ohms maximum resistance) and the (900 R.P.M.) small 10 to 15 ohm variable resistance is connected in series with the motor. Across the small variable resistance a push-button is connected, and by pushing this button periodically, it becomes possible to keep the motor speed quite constant. In setting the speed of the motor in the first place, the rheostats are adjusted until the speed is a little below the 450 r.p.m. (if you happen to be "looking in" at WRNY's television signal), this factor being indicated when checking the speed with the stroboscope fork, by the fact that the black lines on the disc are seen to rotate slowly backward. If these lines rotate slowly forward or left- handed, then the speed of the motor and disc is above 450. together with a tuning fork of the proper All one has to do in using the strobo- Rubber -covered wire or lamp cord may pitch, was suggested by the Editor, Mr. H. scope check for the proper speed, is to regu- be used to connect the rheostats and the Gernsback, and details were worked out by late the rheostats in series with the motor, motor. The small clarostat at the extreme members of the staff. and then repeatedly take a sight on the re- left of the motor baseboard is connected in For the benefit of those who are desirous volving black line disc through the legs of series with the wires supplying the energy of using the stroboscope principle for check- the vibrating tuning fork. The tuning fork (Continued on page 632) ing other speeds than those here given, the following table and formulae will be found useful. STROBOSCOPE TABLE R.P.M. of Tuning fork No. of marks Shaft R. P. Sec. frequency on chart 60 1 128 128 120 2 128 64 180 3 128 42.6 240 4 128 32 450 7.5 128 17 480 8 128 16 900 15 256 17 I 1080 18 128 (72) 7.1 (4) 1260 21 128 6 These formulae will help to solve your problems : here N = Rev. per second of disc; F= freq. of fork per sec.; and M = number marks on disc. Then N = F _ M WGY M =F= N; and F=M X N. 2XAD The following pitch forks are available: WITH 426.6, 256, 128, 288, 320, 341.3, 384, 480, 512. For the benefit of the constructor we have 128 O FORK provided herewith a good size reproduction 2XAF of the stroboscope discs which can be cut out or else copied on to a piece of Bristol -board (1260 R. P. M.) or drawing paper, and either glued or attached to the front of the television receiver. A tuning fork of the proper pitch may be obtained from music stores or from college laboratory supply houses, names of which will be furnished upon request from the editor. For checking the speed of the motor at 450 r.p.m., a tuning fork giving 256 vibrations per second is necessary. This is used This pattern with a disc containing 17 black marks for can also be the 450 r.p.m. specified. For other speeds, cut out and either a different fork has to be used, or pasted to the center of a disc. else the number of lines on the stroboscope When viewed with disc will have to be changed. All this data 128 fork, the design is contained on the drawings of the discs remains stationary at the speed indicated for the reproduced herewith. stations listed.

www.americanradiohistory.com Science and Invention for November, 1928 621

V.T.AMP STER EOSCOPIC TELEVISION Three -Dimension Images Now Obtainable

DUAL SPIRAL DISC

STEREO` SCOPE

PHOTO -ELECTRIC PHOTO-ELECTR C

CELL ! , , CELL _ OBSERVER

The above drawing shows in simple form the principle employed in the new television apparatus. dimension effect is obtained at the receiving end. A photo -electric cell arranged on either side of the subject, picks up the light impulses and changes them into electric pulsations. These are then amplified and broadcast in the usual manner. At the receiving end the usual neon lamp is used, in front of which rotates a spiral disc similar to that used at the transmitter. Two images are built up and when viewed through a stereoscope stand out in relief. The double spiral disc may be seen in the large photograph hanging on the wall. The two sets of holes are clearly seen. Unless the picture received is very small, it will be necessary for larger images to use a bigger neon lamp, that is, one having a larger sized cathode. In the future may we expect a combination of the The illustration above shows the transmitter used for the production of stereoscopic images. three latest advances giving us three -dimension colored radio movies? TELEVISION is progressing so rapidly announced almost daily. Radio that difficulty is experienced in keeping movies and colored television up with the new advances which are now were two of the big steps forward, and now comes the third, stereoscopic images. At the transmitting end of the system, two arc lights cast their beams through two lenses which concentrate the light and direct it through two separate spirals of holes. The holes in this disc are arranged alternately as illustrated and the subject is scanned from two slightly different angles, so that a three -

The photograph at the right shows a view of the receiver with the operator viewing the images through a stereoscope.

<--fcce At the left is a drawing showing the construction of the scanning disc which is fitted with two spirals of holes.

TELEVISION TIMETABLE W. L. Disc Disc Speed Pictures Station Meters Holes R.P.M. Per Sec. Time WRNY-New York City 326 48 450 7.5 Every hour on hour when station is on air. 2XAL 30.91 Same as WRNY WGY-Schenectadÿ 379.5 24 1260 21 Tues., Thurs., Fri. -12 :30-1 P. M. 2XAD 21.96 Same Same Same Tues.-10:30-11 P. M. (WGY and 2XAF) 2XAF 31.4 Sun. -9:15-9:30 (WGY and 2XAD) E. S. T. 3XK-Washington, D. C. 46.7 48 900 15 Mon., \Ved., Fri. -8-9 P. M. E. S. T., Radio Movies 186 IXAY-Lexington, Mass. 51-62 48 900 15 No Regular Schedule 8XAV-Pittsburgh, Pa. 62.5 60 960 16 No Regular Schedule 4XA-Memphis 120-125 24 900 15 No Regular Schedule 9XAA-Chi _ago 62.5 48 900 15 Mon., Wed., Thur., Fri. -9-10 A. M. C. S. T. 6XC-Los Angeles 65.22-66.67 36 1080 18 Will Start Sept. 15th. Daily -10:30-11:30 P. M. P. S. T. WLEX-Boston 62.5 48 900 15 W CFL-Chicago 61.5 45 900 15

www.americanradiohistory.com 622 Science aid Invention for November, 1928 Radio Movies Demonstrated Motion Pictures Sent Via the Ether by New Television System

rate of 16 or more per second, the human eye sees it as a single moving picture. (Edi- tor's Noie: At a slower speed than 16 pictures per second, a fair picture is reproduced, accompanied by a certain amount of flicker. WRNY is using now about 7!.,; pictures per second, and favorable reports of successful reception have been received.) MOVIES PLUS RADIO ALL this the broadcasting of radio movies requires, with the addition that the spots of light must be transformed into frequencies, some of which are in the audible range, transferred to a radio wave and broadcast as electrical energy. In receiving the pictures, the process is reversed, the electrical energy is picked tip, and the frequencies returned to lights and shadow;. which when viewed presents the radio movie. In the first step of the process a pencil of light traverses each picture, or frame, as it is called, at the rate of 60 times each sixteenth of a second. This process produces a 60 -line picture, as clear as the usual newspaper halftone illustration.

EACH PICTURE SCANNED THE pencil of light is produced by a scanner, which is a disc with a series The transmitter used by the Westinghouse engineers for the radio moving pictures is shown in its rim. The the above photograph. Note the film passing before the scanning disc. Each picture is scanned of minute square holes near at the rate of sixty times each one -sixteenth of a second. disc is so arranged that all light is excluded from the film except that which goes through FADERS in radio recently met at the GENERAI. PRINCIPLES the square holes. The disc turns very fast, lamnus Westingl one plant to re- ALTHOUGH the sending of moving pic- and as it turns passes the beam of light view the laboratory progress of what may well he im- across each frame, with the result that an tures by radio, as every part the layman might term imminent agined, required many complicated and deli- individual beam of light touches miracles of sight and sound transmission. cate pieces of apparatus, the principles of of the frame. The meeting was one-of the most important the art are not beyond ordinary compre- The beam of light passing through the in radio annals, -since such work as tele- hension. film falls upon an electric eye or photo- vision, facsimile radio, power tubes, photo - Photography in its simplest form consists electric cell, which is not unlike an over- phone and broadcast motion pictures was of the reproducing of spots of light and sized incandescent lamp. Within the cell, not only reviewed but future progress in shadow in the same arrangement as they however, is a metal whose electrical re- these lines definitely mapped. Of these de- appear in the subject photographed. The sistance varies with the light falling on it. velopments, the photophone is the only one screening of a motion picture, of course, Caeseum, a rare metal, is used in the West- in- which perfection has been attained, at requires that a roll of film be operated at a inghouse cell. The amount of light falling present. The others are in various stages speed which sends sixteen pictures a second on this cell determines the amount of cur- of development, ranging from the near per- before a projecting beam of light. Because rent passing through it. The result is that fection to embryonic laboratory experiments. of the structure of the human eve, if a each individual beam of light sends an elec- The most striking of all radio develop- series of pictures follow each other at the trical impulse which varies directly accord - ments reviewed was the broadcasting of motion pictures which, transmitted on radio waves, were picked up on a receiver located in the television laboratory and reproduced before those assembled there. It was the first demonstration of radio movies by this particular system, and possibly the most interesting of the many advances in the science of radio announced in the past year. While radio movies are still in the laboratory stage, Mr. H. P. Davis, under whose auspices the demonstration was made, states that the event heralds the time when the radio listener will sit at hone and have that most popular form of entertainment, motion pictures, projected by his own individual radio receiver. The development of radio movies is a triumph of scientific engineering. Barely two months ago, the idea came to the mind of Dr. Frank Conrad, in charge of this branch of his company's activities, and the fact that he has brought the device to the laboratory stage in the degree of perfection witnessed a few weeks ago, is said to have set a record. Radio movies are a step beyond previous developments in television and required the invention of a number of appliances in addition to a great deal of scientific calculation, mechan- synchronism of various high-speed Above is a close-up view of the radio movie transmitter shown at the top of the page. The isms, and accurate control of light and scanning disc has a series of minute square holes. As the disc turns, the beam of light passes radio waves. across each frame.

www.americanradiohistory.com Science and Invention for November, 1928 623

. --TRANSMITTER- . ¡ , , . . . . RADIO TRANSMITTER

L. LENS

V.T. AMPLIFIER

LAMP

TO CURRENT SUPPLY MOVIE FILM

DRIVING MOOR

VT AMPUTIER

THERMOSTAT ---

.4 TO CURRENT SUPPLY

TUN NG FORK IN DRIVING CONSTANT TEMPERATURE BOX RECEIVING SET MOTOR 627. AND AMPLIFIER --10 CURRENT SUPPLY

The above illustration shows in detail the apparatus employed in the pro- the laboratory to the transmitter by wire, and two miles back to the jection of motion pictures by radio. In the demonstration described here, laboratory by ether waves. The lower part of the picture shows the main the signals were sent a distance of about four miles, that is, two miles from elements of the 5,000 cycle synchronizing circuit. ing to the amount of light or shade in the cies of approximately 15,000, much of the the broadcasting station by wire and two film through which it passed. radio movie wave is inaudible. miles back to the laboratory by radio. At the broadcasting station these fre- To turn these radio waves back into light, LIGHT BEAMS BECOME RADIO WAVES quencies are super -imposed on a radio wave an arrangement which permits the use of a THE beams of light have now become and transmitted exactly as the ordinary music mercury arc lamp is used. By this adapta- electrical impulses and are sent on to or voice. The radio signals can now be tion the weak radio currents control the the broadcasting station. Here the beams sent across a room, or across the continent. action of the many times more powerful assume definite and varied frequencies, some Their distance range is limited only by the current operating the arc lamp. This ac- of which are audible. Dr. Conrad states broadcasting station's equipment (power). tion may he compared to the action of a that these frequencies range from some- In the demonstration here described, the radio tube, where the weak radio current where near 500 to approximately 60,000. signals traversed a distance of about four on the grid of the tube controls the action Since the human ear is limited to frequen- miles; two miles from the laboratory to (Continued on page 666)

www.americanradiohistory.com 624 Science and Invention for November, 1928

Plane Broadcasts Radio Photo Lindbergh's Picture Received on Rayfoto Recorder

volves the use of a powerful source o: light, a photo -electric cell, a high -gain amplifier, etc. This apparatus was eliminated in this test by using it to record Lindbergh's photograph on a phonograph record. The phonograph record was then used in the airplane to vibrate the needle of an electric pick-up device identical or very similar to the electro- magnetic pick-ups used with the modern electric phonographs. The transmitted signal consists of a 53.3 meter wave, modulated at 800 cycles per second, the amplitude of each one of these electrical vibrations which are sent out 800 times a second, is propor- tional to the amount of light reflected by one of the 38,400 small areas into which the photograph to be transmitted is divided by the "convertor" mechanism which, of course. does its work on the ground and not in the airplane. The work involved in receiving the picture was undertaken by W. P. Asten, receiving engineer of the Radiovision Corpora- tion. The picture at the bottom of the page shows Mr. Asten placing the sensitized paper on the drum of the printer unit. The movement of this drum must be in synchronism with the revolving phonograph rec- in ord the airplane; this speed is maintained Above is a view of the airplane cabin and The unretouched picture as received at WFI by a synchronizing impulse which is re- the phonograph record of the photo. is shown above. corded on the phonograph record, which impulse is received and actuates a relay at AOUT the middle of August of this fraction of a second intervals. The relay again be in step with the phonograph record. year a photograph of Col. Lind- action is such that when the recording drum The sensitized paper is exposed to a small bergh was successfully transmitted moves too far in a given time, due to an spray of blue sparks emitted from a needle from a Fairchild cabin monoplane increase of its speed above synchronous point, under which the entire surface of the and received at WFI, Philadelphia, The speed, it is held motionless by the relay just photographic recording paper is moved by transmission was not entirely successful, long enough so that when released it will the drum. This spray of blue sparks is the however, due to the corona discharge sup- failure of the airplane plied by a radio fre- generator. The er- quency vacuum tube ratic operation of this oscillator. After the generator resulted in transmission is com- the reception of a pleted, the sensitized marred picture. The paper is removed from Ludington Philadel- the drum and devel- phia Flying Service, oped and fixed in the Inc., state that they ordinary manner. The are going to continue results of these tests IN orking along these indicate that high- lines with the inten- grade reproductions of tion of perfecting the photographs can be system. It is said that transmitted from air- about 120 homes in planes in flight to a Philadelphia were receiving station with- equipped with the in five or ten miles. Cooley Rayfoto re- The range, of course, corders required for may readily be in- the reception of the creased to consider- airplane's signals. ably greater distances The transmitter was than this by using tuned to 53.3 meters greater power. It took and used the call let- approximately three ters 3XB. The trans- minutes to transmit mitter was a 75 -watt this picture, and this special short-wave can be considerably radio telephone outfit reduced by developing constructed especially the apparatus, par- for the purpose. Or- ticularly by improving dinarily the transmis- the printer unit. The experiment was sion of photographs by The apparatus above received Lindbergh's picture. The loud speaker w as used for tuning the Cooley system in- the receiving apparatus to the wavelength of the airplane tra nsmitter. (Cont. on page 668)

www.americanradiohistory.com Science and Invention for November, 1928 625 NEB 1tADI0 DEVICES Accessories Recently Developed Which Will Be of Value with Any Radio Set

RADIO OUTLET VOLTAGE DIVIDER INTERFERENCE FILTER STATUARY BRONZE FACE PLATE ANEW voltage divider built entirely in Condensers in Metal CCase one unit and housed in a bakelite case, is r 300.000 OHM now being made by a New York radio p ill 1111 11' VARIABLE manufacturer. By simply connecting the out- 1111111111111.9 11 RESISTOR put terminals of the filter of the eliminator to this unit, the proper plate and grid volt- Plug-in VOLUME ages can be obtained. Two wire wound re- to CONTROL sistors with five variable taps provide flex- Interfering ibility to all receiver current conditions. The Applianc¢,of divider can be mounted in any desired posi- A.C.Set,or SPEAKER tion and because of its neat appearance, it Eliminator JACK lends itself to mounting on the front panel of the eliminator. The flexibility of an ® ... IIIII

Above is a view of the new radio outlet which is furnished wi-h an attractive face plate. Volume can be controlled with the variable resistor. Connections to the set are made as , shown. '7.. ADIO is rapidly taking a more important part in our homes, and in view of To 110v. A.C., VOLTAGE this fact a Chicago manufacturer is now CONTROL or220v.D.C. making a number of radio receptacles fur- KNOBS nished both in statuary bronze and brass. To ° ZMF To 110vA.0 1 of the former is illustrated here 6ND One and or ApplidnCt; is a combined volume control and speaker 2200.0 ° 2MF jack. The plate will fit a standard outlet BAKELITE CASE interference diagram box, or it can be secured in any convenient si?-1- l`s s The filter and circuit manner. The volume control is a three of connections are illustrated above. hundred thousand ohm variable resistor AN eastern radio concern has designed an placed in series with the speaker jack, one interference filter for preventing noises end of the volume control and one end of from the power line from interfering with the jack being connected to the receiver. By the operation of electric receivers or power means of this arrangement, it is possible to VOLTAGES supply devices. This filter may also be used control the volume at one speaker without to prevent radiation and interference from effecting the volume of any other speaker Above is a top view of the new voltage divider to be used with "B" eliminators. oil burners, electric sewing machines, and in the circuit. all similar electric appliances. Two types are available, one which can be- used with a "A" CONDENSER eliminator is governed largely by the re- maximum voltage of 220 volts A.C., or 400 IN order to meet the increasing demand sistance network used. By making the re- volts D.C.; and the other designed for oper- for a low voltage high capacity con- sistance units variable, it is possible to obtain ation with 125 volts A.C. or 200 volts D.C., denser suitable for use in the filter circuit the exact voltage requirements of any re- illustrated here. This filter consists of two of an "A" battery eliminator, a Brooklyn ceiver. A novel feature is the fact that all 2 mfd. in series with mid -point grounded as manufacturer has now made available an the control knobs are calibrated, and a chart shown. "A" power condenser. Three types are be- is provided which shows the exact setting ing made at present, having capacities of for each knob to supply various voltages for COIL FORM 1,500, 2,000 and 4,000 micro farads. When ACHICAGO manufacturer has recently used with a good tube battery charger, or brought out a moulded coil form dry rectifier, the filter condenser will effec- equipped with a five -prong base fitting a tively smooth the output when using the standard UY type socket. The secondary two small choke coils, having an inductance iT1Lii- VENTILATED Am winding space is threaded in the broadcast of about %-henry each. The EI: , q [ "A" conden- METAL SIDES , coil forms, and smooth in short-wave forms. sers are placed in heavy metal cases and ` =1 11i15ee4t1Sll:iii:íl_ i At the bottom of each form is a tickler are provided with suitable mounting feet. slot, which also may be used for the primary. or if desired the primary may be placed WIRE WOUND within the secondary. RESISTORS t'lui ¡i

OPTIONAL I MOULDED THREADED BAKELITE SECONDARY Tot , i. \TO"A" - COIL 1W1i1is11111111nhei SECTION SET RECTIFIER 'A' CONDENSERS mirlimi I FORM OR CHARGER =___ PRIMARY OR TICK. 5 PRONG SLOT The internal construction of the divider may SOCKET e_1111.111 _ be seen above. Two wire -wound resistors are used, with suitable sliders, for varying the voltages.

any receiver from four to eight tubes. In- formation is also given for setting the knobs to meet unusual voltage requirements. Thus the necessity for an expensive high resistance voltmeter is done away with. Adequate ventilation is obtained through two per- MOUNTING FEET forated metal sides. The divider is easily installed by making two connections to the The dry "A" condenser is illustrated above, The moulded bakelite five -prong coil form is and is used in the circuit as shown in the filter of the eliminator. All binding posts illustrated above. These are available with schematic diagram. are marked for the constructor's convenience. either threaded or smooth winding spaces. ( Names of manufacturers furnished upon request)

www.americanradiohistory.com 626 Science and Invention for November, 1928 The Latest in Speakers

A rear view of the elaborate reproducing equipment is shown above. The speakers are mounted upon shelves with the power ampli- The above photograph shows Mr. O. Mampe, of Palisade, New Jersey, whose home is most elab- fier and the eliminator placed at the bottom. orately equipped with radio apparatus of the latest design. One of the most novel features It is important to have the input to each is a huge baffle board used with three electrodynamic speakers. It measures 5V ft. in height speaker in phase, otherwise the radiation in and is 4y1 ft. wide. The baffle is made of wood ?s in. thick and assists in lifelike reproduction. each individual unit would interfere. Mid -Ocean Radiophones

Mr. R. D. Lemert, a Los Angeles engineer, has perfected a radio telephone system which is particularly adapted for communication from ship 200 MILE RANGE to shore. It is now being used on 109 METERS all the vessels of the Wilmington Transportation Co. of Los Angeles, California. It is as convenient and as practical as a telephone between the office and the home, and has recently been installed on eight sea- going tugboats and on the "S.S. Avalon" and "S.S. Catalina." For the past eight months the equipment has been functioning satisfactorily. The above illustration shows the mid-ocean The apparatus consists of an ordi- radio telephone which has a 200 -mile range nary desk type microphone, a small and uses a wavelength of 109 meters. transmitter, a superheterodyne receiver and a loud speaker. Both the transmitting and receiving sets are wavelength of 109 meters and under favor- sealed, rendering them fool -proof. able conditions has a range of 200 miles. The transmitter operates on a Passengers on the ship can talk to the shore at all times through the agency of a transmitter and receiver placed on the company's docks. Orders for the tugboats are now sent by means of the radiophone installation and considerable time is thus saved. The captain no longer has to bring his boat to dock after having finished a particular job. He signals the office when he has completed his work and is then given further instructions. Passengers have approved of the in- The above photograph shows Ronald Colbert, stallations which afford them the means of radio operator of the keeping in touch with their friends on land. "S.S. Avalon," using the Several wrecks have been averted and many radio telephone, by means of which passen- thousands of dollars in operating expenses gers on the ship can be have been saved through the use of the radio- paged from the docks of phone system. An operator is on duty at all the Wilmington Trans- portation Company. The times, both on the tugboats and the steamers. photo at the right shows Besides affording an added means of rapid the interior of the radio communication for the passengers, the mid - room on board the tug- boat "David P. Flem- ocean radio has paid for itself many times ing," with the captain over in directing the tugboats while at dock. calling the office for or- Other steamship lines will undoubtedly fol- ders. The transmitting equipment used has a low the precedent established by the Wil- range of 200 miles. mington Transportation Co.

www.americanradiohistory.com Science and Invention- for November, 1928 627 ßADIO ORACLE In this department we publish questions and answers which we feel are of interest to the novice and amateur. Letters addressed to this department cannot be answered free. A charge of 50c. is made for all questions where a personal answer is desired.

a. moistened finger. If the oscillator tube is oscillating, a click will be heard in the headphones or -peak-er. Another test consists in tuning in a EVACUATED -ration and then removing the oscillator tube from GLASS BULB its socket. If the signal still continues to be heard, the oscillator tube is not working properly. test is to connect a pair of phones in Another THERMO --- HEATER the plate circuit of the first detector between the FILAMENT plate terminal and the 0+ lead, disconnecting the JUNCTION . primary of the first intermediate frequency trans- THERMOCOUPLE FILAMENT former. All the tubes, except the oscillator and WIRE SUPPORT first detector, should now be removed and a local station tuned in. The detector tube rheostat is now adjusted until the signal is just audible. The oscillator dial should now be rotated and if this causes a number of whistles, or if the signal becomes distorted or muffled, the oscillator tube is TO CIRCUIT TO working properly. If no interference is noticed. BE MEASURED ___=_i the oscillator circuit is defective. Usually this will be found to be due to a poor tube, and when G-1

a new one is substituted, the set will again work MICROAMMETER 1 satisfactorily. Connections should also be examined and sometimes the plate and grid leads to of The circuit diagram shows how the voltage the coupling unit will be found to be reversed. the filament is fixed at 84 volts above the point where the grid return is made. The The oscillator will not function if any section of The actual construction of a typical vacuum resistor used should be of the heavy duty the couping coil or the primary" of the first inter- tube thermo-couple is illustrated here, con- type and if desirable may be variable, so that mediate transformer is short-circuited. Lack of nected to a D.C. galvanometer. The leads the correct "C" bias can be easily obtained if oscillation may also be caused by too low or too marked G and G come from the thermo couple the plate voltage is changed, at any time. high a voltage on the oscillator tube. wire, H and H from the heater filament.

"C" BIAS FOR THE 250 LAMINATED BAKELITE THERMOCOUPLES Mass., (653) C. A. McAndrews, Quebec, Canada, (649) M. Chiante, Fairchild, Wis., asks: (651) John Kerney, Watertown, writes: Q. 1. Will you outline briefly the process used writes: Q. 1. Will you please publish a diagram show- and if possible give how I may obtain the necessary 'C' bias for in making laminated bakelite Q. 1. Please show the construction of a vacuum ing properties. my 250 power tube from the "B" supply. :owe of its outstanding thermocouple and how this is used to measure small A. 1. For the manufacture of laminated bakelite, radio frequency currents of one-half ampere or A. 1. On this page you will find a diagram the initial or primary resinoid, which is obtained less? showing how this may be done. It will be seen from the interaction of formaldehyde and phenol, A. I. In many radio experiments or in re- that part of the -B" voltage is used to obtain is dissolved in solvents to produce a varnish. This the necessary "C" bias, therefore the voltage be- search work, accurate measurements of feeble is then used to impregnate the faltric or cloth. alternating currents are essential. For measure- tween the 11+ and B- terminals will have to be Impregnation is carried out with special machines raised. For instance, when using 450 volts on ments of currents present in radio receiving ap- which coat the paper or cloth with a uniform layer paratus, a vacuum thermocouple, such as that shown the plate, a negative grid bias of minus 84 volts into of varnish. These are then dried and cut on this page, is used. The heater element is is required. The voltage between the L'+ and B- these sheets of convenient size. A number of caused to supply heat to a thermo-junction which terminals in this case should be raised to 584 volts sheets are then stacked up and placed in a hydraulic to compensate for bite 84 volts being used on the is connected to a sensitive microammeter. The press where under the action of heat and pressure, heater element and thermo-junction are combined grid. \Vheu using 250 volts on the plate, the a hard plate is produced. The final product cannot in one writ; known as a thermocouple. - The com- "C" bias resistor should be rated at 1,600 ohms, be resoftenecl by heat and is non -hygroscopic. The with 300 volts the resistor should be 1,550 ohms, bination of thermocouple and galvanometer may variety of properties available in laminated bakelite be calibrated by passing through the heater element with 350 volts 1,400 ohms, with 400 volts 1,250 the of and by is determined by amount resinoid a known direct current and the combination may ohms, and with 450 volts 1,545 ohms. It will be the type of laminating sheet used. Physically noted that with 45D volts on the plate the "C" thereafter be used to measure the value of art speaking, laminated bakelite is a dense uniform alternating current. Vacuum thermocouples meas'- bias resistor is rated at 1,545 ohms, while with solid with a smooth and even surface and is obtain- only 400 volts on the plate the resistor is rated are the square root of the mean square of an able in a number of colors. Mechanically, it is alternating current and within wide limits, the at 1,250 ohms, obtaining a bias of minus 70% sufficiently strong so that it can be substituted for volts when using 400 volts on the plate. With accuracy is independent of the frequency of the wood or metal in many cases. . It is free from alternating current. The inductance and. capacity 450 volts on the plate a negative grid bias of is in some variation in structure and stronger of vacuum thermocouples are so low that these minus 84 volts is used. It will be seen, therefore, iron. It has 90 per cent of respects than cast factors can he considered negligible, except- where that the increase in grid bias is disproportional, the tensile strength of aluminum and only one-half so that the plate ecrrent does not exceed 55 mil- extreme accuracy is required and when multiplier the specific gravity. It is the most generally resistances are used. The smaller sizes have a liamperes when using 450 volts on the plate. The is heat - effective organic insulating substance, more heat lag which is negligible, and the larger- show resistor used, as shown in the diagram, is inserted shellac and more water-resistant resisting than a greater lag. With the largest thermocouple, it between the filament winding center tap and the field than fiber. Its application in the electrical takes approximately 30 seconds to reach the full "B" negative. A by-pass condenser of nearly to all and are too and in radio work are familiar value corresponding to the current being measured. is inserted across the two resistor con- is 4 mfds. numerous to retention here. Chemically, it quite The latest' vacuum thermocouples consist essen- is by most reagents. It is nections. The resistor should be of the heavy duty inert and not attacked tially of a thermocouple composed of two wires of most dilute type, as it must handle up to 55 milliamperes at unaffected by most organic acids and by small diameter, the junction of which is attached is, however, attacked by hot 84 volts for a single 250 tube, and 110 milliam- mineral acids. It midpoint of a heater element- consisting of For information concern- to the peres at the same voltage when two such tubes alkaline solutions. more a length of resistance wire, the dimensions of suggest you are used. For any intermediate voltage not given ing laminated bakelite, we would that which depend on the strength of the current tö be the here, the value of the resistor can be calculated obtain a copy of Bakelite Laminated from measured and the sensitivity required. The heater by using Ohm's law. It must be borne in mind, Bakelite Corp. and thermocouple element are connected to separate however, that the voltage between tite B+ and B- wires of low resistance and are sealed inside of plus terminals should be equal to the plate voltage TUBE BRILLIANCY a 'glass bulb which is evacuated to a pressure of the grid voltage. 1 x 10-4 mm. or less. - (652) L. T. GerschWin, Cedar Rapids, Iowa,

asks: ' OSCILLATOR TROUBLE O. 1. I noticed that my 227 detector tube CHOICE OF. SPEAKER varies in brilliancy even when the voltage re- (654) Wm. Pitt, Brooklyn, New- York, asks: (650) E. "f. Bradford, Livingston, Montana, mains constant. Is this an indication of a de- - Q. 1. I would dike to know whether it would asks: or the fective tube? - be better to use an electrodynamic speaker Q. 1. I am experiencing trouble with my super- A. 1. Occasionally it happens that the 227 more common magnetic speaker? heterodyne receiver and have attributed the cause tube does not :always glow with the same bright- A. 1. The electrodynamic speaker will give con- to the oscillator, which I think is not working ness, even though. there is no fluctuation in the siderably better quality, especially when great vol- properly. Is there any way in which I can deter- operating voltage. The` filament of the 227 is -ume is delivered. The volume produced by either mine if the oscillator is functioning properly? pure tungsten which is threaded through an in- type with a given input is about the same. One A. 1. When the oscillator in a superheterodyne sulating --material`. :\t the top of the structure, of the reasons why better quality is obtainable with is not working properly, the "rushing" sound will the filament is exposed and may lie seen through the moving coil type speaker (as the electrodynamic not he heard and the receiver will have lost some the tog of the - bulb.';' A slight difference, in con- speaker is often called) is that it is capable of of its energy. Sometimes, broadcast stations can tact at- this point results in .-the -increase in the producing pure low notes at frequencies below 100 still be tuned in, even though the oscillator is not operating ,temperature, which in turn changes the .cycles. which speakers with iron armatures cannot working. The set is then functioning as a radio brilliancy of the -filamnt. As.. the filament is do. Furthermore, the iron armatúre speaker de- frequency receiver and signals can only be tuned operated below the melting, point of tungsten, this livers a considerable part of the input energy at in by rotating the tuning dial. Turning the oscil- temperature variation °.does :not affect the perform- harmonics of the input frequency, especially with lator dial does not affect tuning. A simple method ance of the tube. Thé}Täct that a tribe may glow large volume. The mass and the elasticity of the of determining if the tube is oscillating is to touch brilliantly is not necessarily an indication" that. it is iron armature mechanism also causes resonant dis- the grid terminal with a piece of metal or with overloäded. _ tortion. - _

www.americanradiohistory.com 628 Science and Invention for November, 1928 Scientific Humor DOUBLE IT AGAIN SAW IT WIFIE: "Do you think you'll invest in that FIRST PRIZE $3.00 Victor told Ralph that he had seen the fourth gasoline substitute concern?" TELEVISION IS HERE dimension on the occasion of last New HUBBY : "No, I figure the substitute would Year's eve, and in fact could explain it. cost twice as much as the gasoline." ''Why Ralph was skeptical, so Victor began to expatiate : WIFIE: "Then wouldn't you make twice here's a wire- as much money ?"-Gleason Pease. "Last New Year's eve I was in pretty high less photo that spirits, and I took a walk down to the rail- you can recog- road yards to clear my head, as I was seeing JUST LIKE IT nize!" kinda double. When I first glimpsed it there Clerk in a Bird Hospital : "Sorry madam, "Yes,it came was a locomotive on the track, but the sec- we can't do anything for you, your bird is as a distinct ond time I looked there were two, and the dead. surprise."- third time there were three standing side LADY; "I know he is, I just brought him ;leason Pease. by side. I got mad and looked again and in to match."-Floyd Swanson. I'll be Banged if there wasn't the fourth dim engine."-Max Bogner. MIRTH-BERTH-HURT THOUGHT JAKE: "Where IT WAS BLUFF ANOTHER SOURCE OF REVENUE did you get that PROF.: "Microscopical investigations lead MECHANIC: us to believe there black eye?" are colors too delicate to "Something dDhi r2'Q be discerned by human BILL : "That's a the eye-invisible wrong with the berth -mark." colors, we may call them." machinery, eh?" JAKE: "Birth- STUDENT: "I know the name of one of LAUNDRYMAN : mark ?" them, sir." "Yes, I don't PROF: "Indeed! is BILL : "Yes, I What it?" know what it can climbed into the STUDENT: "Blind man's buff."-Bert Sop - be but we didn't wrong berth." - pen field. get but five gal- Eugene D. Yates. lons of buttons this week." - ANIMAL BLUSHES LL jokes published here are paid Gleason Pease. for at a rate of $1.00 each; $3.00 LORD BULFINCH : "Is it possible the chameleon girl cares for that frog person?" is paid for the best joke submitted HEATED ARGUMENTS each month. Being a chemist's daughter, she made many DUTCHESS CHEESEMORE: "It looks SO. Every time he comes near she changes Jokes must have a scientific strain hot retorts.-Bert Soppenfield. color."-Mrs. George Smith. and should be original. Write each joke on a separate sheet RISING TEMPERATURE of paper and add your name and ad- Two colored boys were arguing about who USEFUL LIMITED KNOWLEDGE dress to each. was the thinnest of the two. Jonx : "Are you familiar with any medi- Unavailable material cannot be SAM: "Nigger, you is so thin, yo' ma cal terms, professor?" returned. could use yo' fo' a window." PROF : "Only two." RASTU s : "Dats nothing, child, yo' is so JOHN : "What are they ?" thin yo' ma could give you grapejuice and PROF : "Shake well before using, and A SHORT TRIP use yo' fo' a thermometer."-F. W. Tatum. $2.00, please."-Mrs. George Smith. c? Sandy, a HOPE OURS DON'T Scotchman, h a d DiSGUISED just arrived in the WIFE: 'Nov that I have my hair bobbed, "My wife explored my pockets last night." United States on I don't look so much like an old woman." "What did she get?" a steamer. As he HUSBAND: "No. Now you look like an as any explorer-material for a "Same r+mil, walked off the old man."-Bernard Waynick. lecture."-Martin Weiser. ship he saw a man in a diving MURDER ANOTHER USE FOR IT outfit climbing up MECHANIC TO MOTHER: "And from the harbor Tim MOTORIST: "Yes, Toe' how did your to the deck. sir. After careful teacher show you "Mon ! Mon," explained Sandy, "I wish I examination I how fast to had known about that sooner, I'd have find your motor is play ?" walked across myself."-E. Snyder. shot." DORIS : "With a MOTORIST: "I little windshield ON THE SOCIAL SEA knew I had no wiper she keeps "That dentist simply detests parties, but business using that on her piano."- his wife makes him go with her." grease gun!" - Gleason Pease. "Yes, she's always dragging the yanker." Clem Walker. -Gleason Pease.

SCIENTY SIMON. Scientist

(1 GUESS ?HAT SIGN ti1ESÑ T MEAN A SCIENCE. tjS50N ?Htn1G -- -rHEQe5 3O. 24 MAY EASn-4 A GUY GOuJ6- ® FAST SKATER JCR - OVER THAT 51C1M OVER. THIN FORE -OW HAS RD SPOT 4oW;. THE WATER BEI -10 MOUE AWAY A CHANCE OF UNDER. THE PIReS5ORe ICE f THE Serssoinle,

www.americanradiohistory.com Science and Invention for November, 1928 629

LIGHT CIRCUIT WARNING SIGNAL INCENSE BURNER AIRSHIP ANCHORAGE No. 1,671,512, issued to Ellen V. INTERRUPTER Cheeseman. This burner consti- No. 1,584,586, issued to Carl H. tutes a novelty suitable for use as Hauck. This device is shown be- a novelty doll, and for prizes ing used in conjunction with at amusement concessions and like Christmas tree lights to produce a places. Unlike the usual incense twinkling effect. The interrupter burner, it does not have tendency is motor driven and geared so as to to become hot or scorch surfaces in break the circuit about seven times contact with it. Furthermore, it is per second. easily moved without burning the fingers.

No. 1,664,871, issued to Hans Werder. No. 1,670,707, issued to William This improved signal uses a num- Auberlin. This invention provides ber of rotable elements similar to a means for safely mooring an air- the ordinary church bell, when the ship to a mast, especially where a elements are rotated they strike a strong wind is blowing. The struc- resiliently mounted clapper, there- ture includes the wind -shield which ALL RANGE AMPLIFIER by producing the signal. The ele- can be turned around the tower by ments may be chosen with different a motor, to the position required, pitches, so that the produced signal which of course depends upon the will have a pleasing sound instead direction of the wind. The struc- of the usual harsh and offensive PHOTOGRAPHIC ture itself has comparatively little signals now prevalent. This signal EXPOSURE wind resistance, due to its open may be used instead of the usual CALCULATOR framework construction, while the type of automobile or motor launch No. 1,664,818, issued to John R. windshield need be only slightly signal. Hewett. The factors which deter- larger than the nose of the ship. mine the proper time of exposure and choice of stop to be used when taking pictures at any given time VIBROSCOPE and place, such as the time of day, ROTARY ENGINE latitude, etc., are correctly corre- lated by one simple adjustment of the calculator. The calculator is mounted about the lens tube of the camera. hE

ere

No. 1,676,744, issued to Greenleaf No. 1,673,949, issued to Thomas C. Whittier Pickard. This invention Rathbone. This instrument is cap- t i provides a therm oak amplifier able of accurately indicating the which is easily adapted for use amplitude of vibration of a body No. 1,673,632, issued to Victor C. over various wave bands. The con- vibrating or oscilliating from any Mattson. The construction of this struction is such that it is a simple internal combustion engine is such cause. The indicia consists of a of matter for the operator to change number of pairs of lines, each pair that the reciprocating movement range of his receiver and am- the ordinary type is avoided, due to the being spaced at progressively in- rotary plifier. creasing distance, the extent of the the fact that the motion is spacing being indicated on an ad- throughout, except so far as the in vibration, pistons and their connecting rods WALL PAPER REMOVER jacent scale. When are concerned. The feature of the No. 1,674,237, issued to Joseph all the lines are blurred, except the equal motor is its smooth operation, being Bauer. The wall paper remover pair tance almost entirely without vibration. shown here comprises a box form- to then ampliturated de oftsvibration. ing a steam chamber which is attached to the steam line. It is fitted with a handle and a scrap- edge, GARMENT DRIER ing to facilitate the removal LOUD SPEAKER No. 1,670,423, issued to Edward B. NAIL FILING AND of the paper. Ruby. Garments are placed in the POLISHING DEVICE SYSTEM drier as shown bere, and hot dry air is ejected from the supporting members. Garments dried in this way are left unwrinkled, when silk goods are dried in this way, the agitation during the drying period prevents shrinkage.

No. 1,675,031, issued to Fredrick A Bolster. This loud speaker utilizes No. 1,672,450, issued to Leontine a number of units, each unit being Dandeville de Laitte. This nail required to operate efficiently and filing and polishing device carries without distortion over a limited a filing or buffing wheel, and its portion of the audio frequency size and shape is such that it may band. Each unit is constructed to readily be clasped on one band be resonant at a different point in while filing or polishing the fingers the audio frequency band, conse- on another hand. The buffing quently, no matter at what fre- member is readily detachable and quency the input energy is sup- the filing disc quickly and easily plied, one of the units is operating substituted. The device utilizes a at or near maximum efficiency. It flywheel as shown at the left of is claimed that an over-all uniform the illustration, as the power sup- response between 50 and 10,000 plied to the grinding and buffing cycles is hereby made poss'.31e. members is supplied intermittently.

NOTICE TO READERS: The above illustrated and described devices the Patent Office at Washington. D. C., give only the addresses of the have recently been issued patent protection, but are not as yet, to our inventors at the time of the application for a patent. Many months have knowledge, available on the market. We regret to advise that it is im- elapsed since that time, and those records are necessarily inaccurate. possible to supply the names and addresses of inventors of the above de- Therefore, kindly do not request such information, as it is practically vices to any of our readers. The only records available, and they are at impossible to obtain up-to-date addresses. -EDITOR

www.americanradiohistory.com 630 Science and Invention for November,1928

"Oracle" is for the benefit of our scientific student readers. Questions 3. Sketches, diagrams, etc., must be on separate sheets. Questions The to this department cannot be answered by mail free of charge. will be answered here for the benefit of all, but only matter of sufficient in- addressed is which questions will be answered: 4. If a quick answer is desired by mail, a nominal charge of 50 cents terest will be published. Rules under If the questions entail considerable research work 1. Only three questions can be submitted to be answered. made for each question. matter must be typewritten or or intricate calculation, a special rate will be charged. Correspondents will 2. Only one side of sheet to be written on: questions are answered. else written in ink; no penciled matter considered. be informed as to the fee before such

of HELIUM the lowest boiling point known --267.9 degrees C. made of an aluminum alloy with piston pins is another field in which hardened alloy steel on which are mounted double Okla., asks: Drying operation (2277) G. Micado, Prague, helium can be utilized to speed up operation and roller bearings serving to transmit the power to engine case or cam Q. 1. Please give me some information con- make products of superior quality. Water and the driving cam. The main cerning the uses to which helium can be put and other solvents have a higher vapor pressure and case consists of two heat -treated aluminum alloy also if it is now available on the open market. consequently will evaporate more rapidly in an castings. The principle of operation is as follows: of A. 1. Helium gas, which has heretofore been atmosphere of helium than in the air or a vacuum. Each of the four pistons during one revolution considered a rare element and not obtainable on Because it is chemically inert, has high heat con- the crankshaft completes the four strokes, namely, the open market, is now available in commercial ductivity and low density and can therefore be suction, compression, power and exhaust. Other quantities. Unusual interest is being manifested circulated rapidly, it is particularly suitable for four-cycle engines require two revolutions of the in its physical and chemical characteristics in the drying organic and inorganic chemicals quickly crankshaft. field of science, and because of its unusual prop- and efficiently. usefulness perties, it is expected that new fields of Due to its practical insolubility helium may also HIGH -FREQUENCY EXPERIMENTS discovered and developed for the benefit of in the manufacture of will be be used advantageously Rutherford, N. J., industry. toilet preparations for homogenizing creams, soaps, (2279) H. E. Bohec, East The story of helium affords a striking example writes: pastes, etc. how of the way in which unexpected values accrue from To date, the field of usefulness of helium has Q. 1. I am enclosing a diagram showing some fundamental research. The gas was first dis- of its low specific gravity, I intend to use an Ondin coil in performing been developed because give me covered in the sun during the time of the solar its chemical inertness and its low solubility. Some high -frequency experiments. Kindly of August 18, 1868. In 1895, Ramsey, of equal your opinion of this, and if it is advisable to eclipse of the other properties are undoubtedly was searching for additional sources of the newly importance and new developments in industry can employ the electric -chair stunt which pub- in issue of SCIENCE & IN- discovered element argon, discovered traces of therefore be anticipated with the aid of scientific lished the May helium in the mineral cleveite. Later, traces of research in new directions. VENTION. helium were found in Canada and still later in A. 1. In locking over the diagram which we France. It was observed that helium was always published, it will be seen that when the per- found in natural gas in the vicinity of minerals FAIRCHILD CAMINEZ MOTOR former who sits in the chair grasps the piece is to the of a radio-active nature. During the World War, New Jersey, writes: of wire which connected the ground, (2278) B. Adagio, Bayonne. jumps between the- two without Doctor Ramsey suggested to our war department a drawing of the electric spark Q. 1. Will you please publish through his body. The only danger in- that they seek helium in certain natural gas cant motor and also tell me passing Fairchild-Caminez volved is the possibility of getting a spark fields, where the radio -active minerals were pres- its construction. the something of through the body to the ground. It is, of course, ent. - His theory proved to be correct and A. 1. On this page you will find a drawing search for helium was successful. An extraction much more agreeable to perform the experiment plant was then erected in Texas to supply helium according to the diagram which you show. The exclusively for the use ci the United States Gov- performer sits or stands on an insulated plat- ernment in balloons. form and simply absorbs the high -frequency cur- More recently, helium has been made available rent from the free electrode or ball terminal of commercially by the discovery of new natural gas CAM ---,_BALL the Ondin coil. In performing the experiment helium content and the as shown in this magazine, a heavily -insulated fields having a higher BEARINGS development of an improved process of extraction ground cable should be used, and a well -insulated by The Relium Company, whose plant is at Dexter, handle employed at the end of the ground wire, Kansas, with headquarters at Louisville, Kentucky. which the performer holds. Further, it is advisable The first and most important use of helium to for the performer's assistant to throw the Ondin date is for inflating dirigible and passenger bal- coil into the circuit, when the man in the chair loons, of the Shenandoah and Los Angeles type. lias brought the grounded electrode into close Because of the fire and explosion hazard, the use proximity to the metal electrode on the front of of a combustible gas for inflating passenger balloons the head harness. has been banned by the U. S. Government. Helium non -inflammable and its lifting power is absolutely COLORING FOIL is but little less than that of hydrogen. Because (2280) D. B. Ramsay, Hanover, New Hamp- of these two characteristics-lightness and non- LINK shire, asks: inflammability-it is also being used extensively for ASSEMBLY filling toy balloons that float in the air for pur- Q. 1. Is there any process whereby tinfoil can poses of advertising and entertainment. be given a gold color? Another development is the use of helium to A. 1. For a permanent gold color the following is make a synthetic atmosphere of oxygen and helium method recommended. The tinfoil used should for deep sea diving and caisson work involving This diagram shows how the pistons in the first be washed with gasoline until thoroughly labor under abnormally high pressure. The use Fairchild-Caminez aircraft engines operate cleaned. It is then dried and placed in an oven of helium for this purpose minimizes the danger without any connecting rods or crankshaft. where the foil is heated to a temperature of about of "the bends" or "caisson sickness." This ex- 400 degrees F. The foil is held at the temperature painful and sometimes fatal ailment is showing the principle of the cam motor. This mentioned for a period of four to twelve hours, tremely radial cooled be due to the release of nitrogen pre- engine is a four -cylinder stationary the time being dependent upon the size of the believed to four-cycle viously dissolved in the blood due to excess pres- motor and operates on the principle. It foil under treatment. The heating process should sure. The advantage of helium in this instance has a cam type drive and is characterized by a be continued until there is a uniformity in the power output at low propeller speed. Large is that it is not only more inert than nitrogen, high gold coloring over the entire surface of both the but has the lowest solubility in water of any gas overhead valves are used and the bore of 5% in. front and the back. Either tinfoil or alloy foil The tendency therefore is to increase the and the stroke of 4;4 in. make 135 horsepower may be subjected to this process. known. The limits of the pressure at which work of this kind available at 1,000 R.P.M. of the propeller. The process described here is understood to be can be performed, greater depths in diving work, motor weighs 340 pounds, with the exception of one of oxidation. The oxidation of the surface for instance. It also lessens the time of com- starter and propeller hub. Due to the low speed of the foil produces the gold color which is desired. pression and decompression of the operator, which of rotation, propellers from 10 to 10% ft. in In order to insure a uniformity of coloring, the some types of is an important factor. diameter may be used with this foil should he retained in the oven after the heat Helium not only has low solubility in water, but engine. The clearance between the roller and cam has been cut off and allowed to cool slowly, thus 1 alloy is also practically insoluble in molten metals. For is /64 in. The cylinders have aluminum completing the coloring operation. When the oven this reason, it is used in preference to other heads, which are screwed and shrunk into steel - has become cooled, the foil may be removed. The non -oxidizing gases such as nitrogen and hydro- finned sleeves. Cooling fins are machined on the higher the temperature, within certain limits, the gen, in annealing processes and metallurgical oper- steel cylinders. Cylinders are bolted to the case deeper will be the gold color. ations. It is also used as a damper for nautical but heat -treated piston guides extend into the instruments because of its aluminum alloy case, so the pistou at no time and other scientific CELLULOID SOLVENTS high viscosity, which is greater than that of air, overruns the cylinder. In place of the usual its high thermal conductivity, which is more than crankshaft and connecting rods, a driving cam is (2281) G. C. Mackintosh, Boston, Mass., asks: six times that of air, its high specific heat, and fixed to the main shaft. The rollers in the pistons Q. 1. What are the principal celluloid solvents? low dielectric constant, etc. It is being used for hear upon this cam and are kept in contact with A. 1. Celluloid dissolves in acetone, sulphuric filling radio tubes and glow lamps and tubes for it by two sets of piston interconnecting links. ether, alcohol, oil of turpentine, benzine, amyl ace- signs and as a cooling medium in electric trans- The mainshaft is a straight hollow shaft, 22 in. tate, and the like. Various combinations of these formers and high speed generators. Helium has long, and is made of alloy steel. The pistons are agents may also be used.

www.americanradiohistory.com $'cience and Invention for November, 1928 631

From the Torture - Dungeons of the Inquisition comes this Tragic Revelation

IT is with a chilling shudder of horror that modern people look back upon the fearful persecutions of the "Holy" Inquisition. Shame and fear have kept the facts concealed. But now the torture -dungeons speak from their blood -stained stones and give up their gruesome secrets; the whole story is told in all its grim details. The tragic revelations of persecution and torture have been torn out of hidden records. Now they stand exposed to all the world in this one, splendid, fascinating, daring volume-"THE STORY OF THE INQUISITION." ci 100 Illustrations Showing the Methods of Torture NOW COMPLETE IN ONE VOLUME $ 3 Over 600 pages --More than 100 Illustrations --only EVER before has it been possible to This J Partial Contents of 1 \I get the whole appalling story of the Edition Limited Inquisition into one volume. The records MAIL COUPON NOW "The STORY OF THE were scattered across half of Europe; and if not destroyed were kept well hidden by MOST books containing 600 pages with INQUISITION" those who feared the effects of their dam- over 100 illustrations usually cost The Papal Inquisition ning exposures. $7.50 to $10.00. But because "The Story Inquisitors of the Sea But cautiously and bravely a group of of the Inquisition" is so vastly important, historians have collected the facts. They and will be wanted by so many thousands Methods of Torture have searched Papal bulls, court records, of people, we have decided to offer a lim- Description of an Auto -da -Fe ecclesiastical files, royal archives for exact ited number of copies at the remarkably Licentious Judges and authentic names, dates and numbers. low price of only $3 (plus 20 cents for Corruption in Office Ancient manuscripts have bec -i discovered delivery charges). Due to the tremendous full of pictures of .on cost of printing such a large book, it is and Excommunication the Inquis. tortures. Curse All of it has been put into this one not known how long we can continue to A Holy Trinity of Parasites massive volume of 600 pages. The facts offer this daring, fascinating volume at The Martyrdom of Bruno you can read in this book-perhaps for the such a bargain. The next edition may cost more. The Persecution of Jews first time - are more amazing and more Therefore, make sure that you get startling than we can hope to describe. You your copy now while the low price is still The Persecution of Protestants must read the book itself to grasp the whole available. Mail the coupon at once. The Jesuits grim story. Only in this daring, fascinating The Witchcraft Delusion book do you learn the names and titles of The Freethought Press Assn. The Pope, the King, and the Spoils the arch criminals. Only here can you get Dept. S. I. 250 W. 54th St., New York the authentic records of their Disreputable Character of Inquisitors greed, their lewdness, their r- Female Slaves in Demand tortures, their crimes. TILE FREETHOUGHT PRESS ASSN., Dept. Si, A Vice Society 250 West 54th St., New York. Here is the hook for which The Inquisition in England I accept your special offer to secure a copy of "The Story the world has waited nearly of the Inquisition" in one complete volume, and I enclose Prosecutions in Germany 500 years: "THE STORY remittance for $3.20 (which includes delivery charges) for An Inquisitorial Seraglio OF THE INQUISITION"; which you are to send me this valuable hook prepaid. complete and unexpurgated, The Persecution of Galileo written for all people who Name The Crusades want the truth told without The Conflict Between Religion and fear or favor. There are also Address Science added two valuable chapters Profusely illustrated with more than dealing with "The Witchcraft City and State 100 pictures taéen from original wood- Delusion" and "The Conflict cuts found in old manuscripts during Between Religion and Sci- A limited number of copies of "The Story of the Inqui- the time of theInquisition. sition" have been bound in rich Artcraft Leather with title ence." stamped in gold. If wanted add $2.00 to your remittance. E Check here if you desire the book sent C.O.D. Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com 632 Science and Invention for November, 1928

Before Kenneth McCarty Mailed that Coupon How to Build S. & I. Is Your Car He was an Television Receiver (Continued front page 620) $18°O clerk -- 1GasEarer New Invention Increases Today to the neon tube. The terminal posts to the Mileage on Auto Gas neon tube circuit are mounted on a piece of Eater from to 34.6 His bakelite, secured to the rear left corner of 13/ the baseboard. A rubber foot should be Miles on a Gallon An astonishing new device has been Income placed under each corner of the baseboard; perfected that is amazing car owners this will allow the wiring to be simply everywhere. Goerzen reports Increase from 1355 to 34.6 miles on his Dodge. is placed against the wood and held in place Thousands have been installed and users report 30.40-50 and more miles $8500 with a few staples, if necessary. The claro- on a gallon of gas. In addition power stats are mounted on small right-angle is increased, instant starting and flashy iron. The pick -op is noticed and carbon formation Week brackets made from brass or disappears. Every car owner in the country needs this new in- a push-button is placed ill a tight -fitting hole, vention. Its cost is so trivial it pays for itself in a few days time, After completing the yet it will save hundreds of dollars for its owners in gasoline. course ho wrote us: bored through one corner of the baseboard. "Yours is the finest course ever presented for the The 110 -volt supply for the motor circuit is $100 a Week Territory Open Tenor Banjo. Before I enroll- through an ap- $5.00 an hour for spare time. Men are needed in every locality to ed with you, I knew nothing brought into the apparatus, take care of the tremendous local demand. Sales ability is nut re- whatever about music. I was proved socket or receptacle, mounted on the quired. Every car owner will buy on sight. Ideal for spare Iles 105lIre. Play for Fun or earning $18.00 weekly clerk- as shown To help our workers we famish them with this mar- ing in a store. Little did I righthand side of the baseboard, FREE velous Whirlwind gas saver free for their own cars. a realize the opportunity that in the picture. Quick action is necessary. Be the one in your locality to cash $5,000 Year had come.I took up the course in on this device which every auto owner will buy. Send today just for fun. But here I am, for full particulars and free sample offer. Whether a salary of $65 to playing in one the OPERATING THE APPARATUS $100 a week -or spare-time of best or- 9M2WKETMdWSrC playing at $5, $10 $16 or more chestrasin Western Michigan Whirlwind Mfg. Co., a night-interests you or not and making $85.00 a week. WHEN the television signal is being -think of the fun in store Your course and your kind received and the neon tube is con- 'The Wonder Hotel of New York for you. In one to three cooperation have made me a months we can train you at professional Tenor Banjo - nected to the output of the radio receiving borne to play this marvelous, lat." Kenneth McCarty, Park - melodious instrument with a view Hotel, South Maven, Mieh. set (and providing there is sufficient voltage HOTEL MANt ER fine, easy skill that will make You Get Phonograph used in the last stage-not less than 180) you the envy of all other Records too Heart of 7th Ave. 50 -51st Sts. eyes. You're passing up the Every selectionof this course pulsations of pinkish light will be seen in best tintes of your life if you -fifty-five in all -comes to neon tube. If a sufficiently high voltage District q. New York City pass up an opportunity like you on a phonograph record. the this to learn at slight cost and You hearths instruc- is used and the radio apparatus is properly with no inconvenience at all tor's playing just as bias, etc., the world's most popular in- though be were adjusted with regard to the "C" 2000 Rooms strument. Decide NOW to right atyourside. then a pulsating pinkish light should be seen learn more about The Play- The Play -Way is Way-the quickest, surest, different, inter. covering the whole neon tube plate which Rooms with run- short-cut to social and pro- esting. FOOL- ning water . e $2.50 fessional success. PROOF. Get thegood news the coupon For two . . a FREE Book TUNING FORK 3.50 SEnNBD Tells How FOR IT TWISTED Rooms with shower Send at once for "The Play - Way to Popularity and Big NOW! or bath and Pay." Learn all about our shower . . 3.00.500 unique method of training you at home , about the big, Tenor Banjo, Phonograph Re- cords and Outfit that we send For two 4.00.5.00.6.00 you along with your very first lesson. Pleasure,pop- AT CORRECT ularity and big pay are open SPEED OF DISC, No Higher to you! Get this FREE DESIGN APPEARS Rates Clip the coupon while Book. STATIONARY it's here before your eyes !

The tuning fork must be so twisted that A. F. Bloch, President, either the upper or lower leg is closer to New York Academy of Music, the eye. The aperture between the legs Make;'f+o Studio 4118, 100 Fifth A e should be very small. The entire pattern New York City. can be viewed if the fork is held close to Send me the book that started McCarty: the eyes. Money No obligation whatsoever on my part, understand. faces the rear of the television disc. If the In Name pulsating glow is seen on the rear plate, ELECTRICITY AaareG_------then the wires leading to the neon tube must be reversed. Learn in Los Angeles! If you are "looking in" with the television BE an electrical specialist. Gain quick success in this most receiver, and, having checked the time of fascinating and profitable field. Learn at National inthecenter of Be a Taxidermist tremendous electrical projects costing more than $100,000,000.00 the television broadcast with the newspaper -unlimited opportunities now. Learn by Mail program, you should first check the motor Practical, intensive training by National's job -experience method speed and make certain that it is revolving in 6 to 9 months. All technical essentials included. School endorsed by leaders in electrical industry. You learn all branches at the prescribed speed. As you look into of electricity; radio. Million dollar institution, all modern the viewing visor, preferably in a darkened equipment and training facilities. Life scholarship. No age limit. Free employ. Fil corner of the room, you will see successive ment service. Over 17,000 successful REE lines of orange -colored light as the spiral graduates. 23rd year. Big, illustrated of holes repeatedly scans the illuminated 84 -page catalog sent FREE. Write today. BOOK plate in the neon tube. If you see these wt.EL ICALScRo0L bands of light, but they only form irregu- _De r 108E 4006 Su. Figueroa. LOS ANGELES CALIF. lar splotches, then the chances are that your motor speed is either too high or too low, and a slight change in the rheostats should be made. It is well to recheck the speed N T . ri,rnll!}r,jC CARDS of the revolving disc with the stroboscope 'We quickly teach fork after doing this, as you may change f 9ndSO mo or 1``u ini mere Learn to mount all kinds of game, birds, animals, fish-tan the speed too much. mend. s future.future.ai lotezestiotInI teresting furs, make rugs, robes, etc. You can now learn this fas- work. Oldest and foremost nasal. cinating art in your own home during your spare Several things may happen if you are suc- EARN $50 TO ;200 WEEKLY " time. The lessons are interesting and easy to understand. cessful in building up a picture image John Vanua, N. T., cis Us for single show $' Great sport and lots of fun. Big money for your spare time. with card. Crawford, B. C., writes: "Earned e' the machine ; the image may be upside down while taking comae." Don't delay. Send today Mount Your Own Specimens or it may slowly drift across the viewing for complete information samples and guarantee. Decorate you home with beautiful specimens that you have DETROIT SCHOOL OF LETTERING caught and mounted yourself. You can make big money lens repeatedly. If the picture slowly drifts 179 Stimaou Ave. Est. 1899, DETROIT. MICH. doing the work for others. Many specimens are becoming very across the lens, then the motor speed should rare and sell for high prices.Over 100,000 students have learned Baty .peclmenst« im: have made be momentarily accelerated by pushing the over $550.00 donna spares time addlingd and meint- Ing for others". We have thousands of eiouler letters. button connected across the smaller resist- Expl ns th.Bc« n ieiderrm, Ctntells.,danens ance. This presupposes that the motor is FREE of photos of mounted epecireens. Every bunter or trapper should have this book. Tells you how you ern Learn this running slightly below the correct television fascinating art easily end quickly from our school. Sent you absolutely 1 can make a good penman of son at home during you. No obligation. Just send name end address. Write speed for the station to which you are "look- m are tire.. Write for my FREE BOOK. NOW TO free. today! BECOME A GOOD PENMAN." Your name eiegantlr 3798 written on a nerd if Northwestern School of Taxidermy OmahaElw ÑebrBldg.. ing in." You may have to change the small rou enclus. stamp Write today. (Continued on page 634) F.W.TAMBLYN, 424 Ridge Bldg., City. Mo.i Please sal' you saw it in SCIENCE, and INVENTION

www.americanradiohistory.com Science and I,:vention for November, 1928 633

)C )C 3E )C )C )C X 3C X )C 3 E - Another Thrilling Drama of the Skies!

TRACER bullets whistled! Zoom- ing planes roared their death songs as this daring Ameri- can "ace" hung in the skies as bait for enemy Fokkers. You'll enjoy every word of

14 other SKY thrilling BAIT Stories of By the War! Raoul Whitfield I in the NOVEMBER

October November issue still issue on Sale on Sale October 20th

The Popular Magazine of Thrilling War Tales of the Army, Navy and Marines ALSO SMASHING STORIES ì" - by BATTLE STORIES MAGAZINE Nov. Scl.&Inv. -- Fawcett Publications, Inc. GUY Minneapolis, Minn. ARTHUR EMPEY Inelosed please find $1 (bill or stamps), for which send FRED C. PAINTON me Battle Stories for the next five months. J. ALLAN DUNN Name

CAPTAIN ELIOT Address

HAROLD F. CRUICKSHANK City State and others

C )f X X 1C X )Q )C - X )C X X X ) Picas(' say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com 634 Science and Invention for November, 1928

Gain Vigor and HOW TO BUILD S & I TELEVISION RECEIVER Manliness (Continued from page 632) THROUGH STRONGFORTISM B9 defiant. courag- eous and MANLY! You won't be regarded as a The photo- real man by men or women graph shows if you are a slouching, ner- operator vous, fidgeting grouch- checking t h e slinking along, afraid of your shadow, timid in speed of the company; with catarrhal television re- breath, rheumatic, consti- ceiver by pated, dyspeptic - round means of a shouldered; with unsteady tuning k step,-a cold, clammy grip; for -lacking pep, punch or and a pat- personality- you simply terned d i s c. won't get anywhere. FEL- When viewed LOWS OF THIS TYPE through t h e ARE NOT WANTED. tines of a vi- If you are a weakling- brating fork, sickly, nervous and always h pessimistic-you will feel t e pattern your inferiority wherever remains s t a- you go. Men will shun you. tionary, ex- Women will not be at- actly as y o u tracted to you. Even dogs see it here. will bark at youi IT IS THE PENALTY YOU PAY FOR WEAKNESS!- but you won't have to pay this price If you will face the facts and make up your mind you are going to go to the mat with ill - health and fight to a finish. It's up to you-TO YOU ALONE. You can overcome weakness. variable resistance or even adjust the larger duction type, with a separate starting wind- You Can Be Strong one slowly in order to make the picture sta- ing, then the direction of rotation is re- Like thousands of those tionary on the lens. versed by simply transposing STRONGFORT who have come to me in a the terminals pitiable state of physical If the picture is upside down, then you from the starting winding. If the motor Builder of Men bankruptcy, you can be restored through STRONG- are scanning the neon tube plate in reverse happens to be one of those types using FORTISM, the basic science of health and strength. order; that is, from bottom to top, instead copper shading plates, mounted on the tips You can be raised from the depths of despair and despondency to the heights of glorious manhood. of top to bottom, and the disc must be taken of the iron stator poles, then the direction You can be powerful, vigorous, manly, happy and off and turned around. In some cases it will of rotation be successful if you but give Nature a chance to work can effected by remounting through my proven system. be necessary to turn the disc around and also the shading plates on the opposite pole tips; reverse the motor, or in still other instances, or simpler still, the whole stator frame in order to rectify the picture image, the may he removed from the car -case or motor STRONGFORTISM direction of the motor rotation have YOU will to housing, and reversed in its position with WILL MAKE A HE-MAN OF be reversed. respect to the same. Through STRON GFORT ISM men all over the world have been rejuventated and restored to health and If the motor happens ,to be of the uni- In some cases direction of rotation of the strength after they have suffered untold mental and versal type, which means that it is usually motor may be effected by sliding physical harrors as the is evitable result of excesses, the shaft fast living,and abuse of their physical powers. a series -wound motor, then the direction of out of the rear bearing and then turning STRONGFRTISNI has a record unparalleled-there rotation can be changed by simply reversing is no other system, or m ethod, or course that com- the motor around. This is rarely the case, pares with it in restoring Impaired human beings to the connections to the field or to the arma- but with some induction motors it is pos- virile, manly strength by utilizing Nature's forces scientifically. It builds up the internal muscular sys- ture brushes. If the motor is an A.C. in- (Contiuued On pane 636) tem first and thus gets rid of CONSTIPATION, DYSPEPSIA, INDIGESTION, HEART AILMENTS, BAD BLOOD, CATARRHAL TROUBLES, RHEU- MATISM and other a ttli tions, increasing your energy and sta mina. External muscular development follows quickly and you become a new man Inside and out-a fellow to be reckoned with and envied wherever you go. I Want To Send You MY FREE BOOK This book of many pages and dozens of pictures tells of my wonderful experience-how I became the outstanding athlete of the world, performing feats others dared not attempt; how 1 turned the knowledge gained through developing my own body to the benefit of others, and then how STRONGFORT ISM was evolved. It tells what I have done for others, what I can do for you. It doesn't mince words. It tells plain truths. "Promo tion and Conservation of Health. Strength and Menta I Energy" points the way from disease and weakness to health and strength. It is priceless. I'll send it to you on request-FREE. Write for your copy today. ÇTh iG}'®OT IIliSf TUT LIONEL STRONGFORT. DIRECTOR.49 PHYSICAL AND HEALTH SPECIALIST DEPT. 631 NEWARK. NEW JERSEY. U.S. ,

CLIP AND SEND THIS FREE CONSULTATION COUPON Mr. Lionel Strongfort, Strongfort Institute, Dept. 631, Newark, N. J.-Please send me absolutely free my ropy of your book, "PROM OTION AND CONSERVA- TION OF HEALTH, STR ENGTH AND MENTAL ENERGY." I have mtrked (x) before the subjects In which I am most Interested. ..Catarrh ..Overweight .. Great Strength ..Colds ..Constipation ..Vital Losses ..Asthma .. Weak Back ,.Lung Troubles ..Headache ..Weak Eyes ..Round Shoulders ..Rupture Rheumatism .. Youthful Errors ..Thinness ..Nervousness ..Manhood Restored ..Pimples ,.Night Losses ..Stomach Disorders . Insomnia ..Short Breath ..Increased Height .. Impotency ..Weak Heart Muscular Development Private Ailments Name Age Occupation Further details of the television receiver. 1, double convex lens; 2, cone; 3, aperture; 4, clips 7, 8, Street for holding cone; 5, face plate; 6, screws for holding same; top; screws for bolting to plates 12; 9, single hole mounting of socket 10; 11, neon lamp; 13, bolts for holding plate 12 to upright City State 14; 15, holes for mounting uprights to motor; 16, mounting for disk held in place by screws 17; 18, shaft mounting. Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com Science and invention for November, 1928 635 EKG AL POE THE FATHER OF SCIENTIFICTION GREATEST OFFER a EVER MADE 10 Volumes Never before has it been possible Cloth Bound to obtain the complete works of America's greatest author and OVER 2000 PAGES genius, Edgar Allan Poe, for the amazingly low price that we now The complete offer them to you. works of Edgar Allan Poe are published Edgar Allan Poe in 10 has come to be beautiful volumes. Handsome looked upon as the greatest liter- red ary genius cloth cover. Special egg-shell that America has ever paper, made produced. He is the originator to order for this set. of the first Printed from plates made for the "Scientifiction" stor- well-known ies-fiction wi-_h a plausible sci- Richmond Edition. entific background. Jules Verne Each volume contains an average and H. G. Wells freely acknowl- of 200 pages. Size of type is long edge him as the originator of primer, which is easy reading and modern scientifiction.* In addi- restful to the eyes. The volumes tion, there is li=tle doubt but that are handy in size, 4 x 6/ inches. the well, known SHERLOCK The greatest offer ever made. HOLMES is the product of the This is the chance of a lifetime. inspiration that Sir Arthur Conan Like a razor also, the pendulum was Take advantage of this astound- Doyle massy and heavy, it was appended to found in the works of Poe. a weighty rod of brass, and the whole hissed ing low price offer. Fill in the Take advantage as it swung through the air. I saw that of this special the crescent was designed to cross the coupon now. Send no money introductory offer. There is just region of the heart. Down-steadily down pay it crept. The rats were wild, bold, raven- the postman $2.75 on deliv- a limited number of copies in this ous, their red eyes glaring upon me. And ery. We pay the mailing edition. then From "The Pit and the Pendulum." charges in U. S. *All Scientifiction Stories in list CONTENTS OF THE SET of contents are identified with \bstery of Marie Boget. "The Balloon Hoax Fall of the House of Usher. VOLUME FIVE a star and printed bold face. Found in Silence--A Fable. 'MS. a Bottle. "The Tell -Tale Heart. *The Oval Portrait. VOLUME FOUR "Berenice. Ligeia. Eleanora. VOLUME ONE The Masque Morelia. VOLUME THREE of the Red Death. 'A Tale of the Ragged Mountains. Memoir of Wm. H. Rogers. The Cask of Amontillado. 'The Spectacles. Eulogy by James Russell Lowell. "The Purloined Letter. 'The Imp of the Perverse. King Pest. Notice by N. P. Willis. 'One Thousand and Second Tale of The Island of the Fay. Scheherazade. 'Three Sundays in a Week. Adventures of Hans Pfeil The Assignation. The Devil in Belfry. *The Gold Bug. 'A Descent Into the Maelstrom. "The Pit and the Pendulum. Lionizing. tho Four 'Von Kempelen and His Discovery. The Premature Beasts in One. Burial. S-ing a Paragrab. "Mesmeric Revelation. The Domain of Arnheim. VOLUME TWO 'Farts in Case M. Valdemar. Landor's Cottage. VOLUME SIX Murders in Rue Morgue. 'The Black Cat. William Wilson. Narrative of A. Gordon Pym. VOLUME SEVEN Metzengerstein. The System of Dr. Tarr and Prof. Feller. The Literary Life of Thingumbob, Esq. How to Write a Blackwood Article. Predicament. The Angel of the Odd. Mystification. Mellonta Tauta. Diddling. The Duc de L'Omelette VOLUME EIGHT VOLUME TEN *Sonnet to Seienee. The Oblong Box. Complete Poems. "Al Aaraaf. Loss of Breath. The Raven. Tamerlane. 'The Man That Was Used Un. Tho Bells. Etc. The Business Man. The Landscape Garden. 'Maelzel's Chess Player. SEND NO MONEY! Poems of Words. The Colloquy of Monas and Una. rPopular Book Corporation, The Conversation of Eros and Char- mian. 1 102 Park Place, New York City Shadow-A Parable. Gentlemen:- Philosophy of Furniture. Please send me at once, the complets works of A Tale of Jerusalem. Edgar Allan Poe, consisting of 10 volumes, as 'The Sphinx per your advertisement. I will pay the postman $2.75 upon arrival of the books. There are no VOLUME NINE extra chargea of any kind, whatsoever. If the Hop Frog. books are not as represented. I will return them The Man of the Crowd. to you within three days and you are then to Never Bet the Devil Your Head. return me my money. Thou Art the Man. (Free delivery only in U. S. Extra postage for Why the Little Frenchman Wears foreign countries.) His Hand in a Sling. Bon Bon. Some Words with a Mummy. Name The Poetic Principle. The Philosophy of - Composition. Address Old English Poetry. City State POPULAR BOOK CORPORATION, 1Ó2 NEW ORKACE Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com 636 Science and Invention for November, 1928

HOW TO BUILD S & I TELEVISION RECEIVER (Continued from page 634)

sible to do this, the rotor being secured to NEON TUBE NOTES the shaft by a set screw. IN adjusting the neon tube circuit, it is the The - television set builder who is inter- usual practice to adjust the "C" bias on ested in the connections of the resistance- the last amplifier stage, so that the tube coupled amplifier, and other details con- just glows over the plate facing the rear of nected with the radio receiving set, should the revolving disc. In other cases the neon read all about this matter, where complete lamp is adjusted by raising the "C" bias "There's the new diagrams are given with explanatory re- potential on the last amplifier tube, so that 99 marks, in the Television magazine, Volume Ned Tyson I, No. 2. Various methods of connecting the neon television lamp are supplied by OPTIONAL LISTENING CIRCUIT He's making $6500 a year now some of the manufacturers putting out these INPUT P STANDARD FROM Bt.I "I USED to know him when I was a kid-we tubes. The common connection for the - V.T. SOCKET AMPLIFIER COXDENSER E"--'PHONES PHONES went to grammar school together. neon lamp, however, is in series with the NEON his died and he go to PLUG 10 TUBE "Then father had to plate and supply wire ; in other words, "B+" MPG. work. Got a job with Brooks & Watson as a To I Yf .r' i it is connected in the same relative posi- SU 11 clerk, but couldn't seem to get ahead. tion as your loud speaker. Some of the . ioPTwruU,Ñ "Then overnight something seemed to wake VARIABLE / 'FAN MOTOR HIGH RESISTANCE neon lamps, however, are supposed to be (ABOUT H. P.) him up. He began making suggestions to the TO CONTROL it firm-helped them to save a great deal of money. checked carefully with a milliammeter, so NEON TUBE in "Then Old Man Brooks became interested- that no more than a certain current mil- PUSH BUTTON wanted to know how Ned happened to know so liamperes is passed through them, in order 100 TO 150 10 TO 15 OHM much about the business. Ned told him he'd been to conserve their life. When using one of OHM RESISTANCE VARIABLE RESISTANCE studying at home at nights through the Inter- these more sensitive type neon lamps, it will national Correspondence Schools. 'H'm,' said Mr. be found necessary to connect a clarostat, Above is a schematic diagram of the Science Brooks, 'I'll remember that.' in and Invention television receiver. A push "He did too. Put Ned out on the road as a or other fairly high variable resistance, it button cutting a resistance out of the circuit salesman for a year or so and then brought him series with the "B" supply, before reaches speeds up the motor when necessary. into the main office as sales manager. the neon tube. This series variable resist- "He's getting $6500 a year now and everybody ance in the neon tube circuit may have a the neon lamp doesn't quite glow. In this calls him 'the new Ned Tyson.' I've never seen range of 0 to 10,000 ohms. A fixed resist- case, when the television signal comes in, such a change in a man in my life. The I. C. S. ance of 10,000 ohms, with a variable _,000 - the lamp lights up as the television signal deserves a lot of credit." ohm resistance, may be used. In the Schools course pulses are impressed on the circuit. In some An International Correspondence Volume I, No. 2, will help you just as it helped Ned Tyson. It Television magazine, cases it may be possible that you see the will help you to have the happy home-the big- already referred to, details will be found image in negative form instead of positive, ger salary-the comforts you'd like to have. for making your own rheostats for the speed i. e., you may see the image similar to a Start today to make good. At least find out control of the motor, as well as data for photographic negative. In this case the con- what this great school can do for you. building an adjustable impedance for those nections to one of the amplifier stages should Mail the Coupon for Free Booklet using A.C. motors; the variable impedance be reversed; at other times it will be found being preferable to variable resistance con- that if the tuning dial of the set, or one of INTERNATIONAL CORRESPONDENCE SCHOOLS trol, where alternating current is used. the dials, if it has more than one, may have "The Universal University" When all ready to listen in for a tele- to be moved from the right side of the peak Box 6167-F, Scranton, Penna. vision signal, you will soon become accus- Without cost or obligation, please send me a copy of of the carrier wave, so to speak, to the your booklet, ^Who Wins and Why," and full particulars tomed to the peculiar whining note of the left side and vice versa. That is, if you about the subject before which I have marked X: television signal proper; and if you follow had tuned the dial to say 45 degrees for BUSINESS TRAINING COURSES the published program of WRNY, for ex- Business Management Advertising maximum signal strength, and then detuned Industrial Management English ample, you will receive the proper intro- a little toward the left; you may have to l'ersonnel Management Business Correspondence announcer, and then you will Traffic Management Shmv Card and Sign duction by the detune toward the right of the peak, 45 °Accounting and C. P. A. Lettering make no mistake when you hear the tele- degrees, in order to reverse the image. Coaching Stenography and Typing vision signals in your phones. Cost Accounting Civil Service Another reason for a reversal of the im- Bookkeeping IDRailway Mail Clerk If you "listen in" to the station at first Salesmanship Common School Subjects headphones and plug them age from positive to negative is that a D Secretarial Work High School Subjects with a pair of has to be used Syanish French Illustrating D Cartooning into the detector jack on your set, this is certain number of stages TECHNICAL AND INDUSTRIAL COURSES if connect your head- with a specified form of detector circuit; all right; but you in an article Electrical Engineer Architect phones in the last stage wherein the neon this is explained at length Electric Lighting D Architects' Blueprints covering an interview with Mr. C. F. Jen- Mechanical Engineer Contractor and Builder tube is connected, he sure to connect a 1 D Mechanical Draftsman Architectural Draftsman kins' radio engineer, which appears in Tele- D Machine Shop Practice Concrete Builder micro -farad condenser in series with the D Railroad Positions Structural Engineer in vision magazine, Volume I, No. 2, page 8. Gas Engine Operating Chem istry U Pharmacy phones, when connecting them the place Civil Engineer Mining Automobile Work of the neon lamp, or across the neon lamp If you happen to see the television image D Surveying and Mapping Airplane Engines will D Plumbing and Heating D Agriculture and Poultry terminals. The television signal sounds in on the lens right side up reversed, you ill Steam Engineering 01Radio ['Mathematics general like a buzz saw cutting through have to reverse the direction of rotation of changes the motor and also remove the disc from Name a plank, and the note continually as the person in front of the television the shaft and turn it around with the other Street Address transmitter moves about. side out. City State 1/ yon reside in Canada, send this coupon to the Interna- tional Correspondence 6choofs Canadian, Limited, Montreal HOME MOVIES Conducted by DON BENNETT CHEMICAL EXPERIMENTERS (Continued from page 609) The manufacture of motion picture 1 The Movie Question Box A. u`I' equipment is a job requiring excellent tools (This department is conducted for the and great mechanical knowledge. It would benefit of the readers of SCIENCE AND IN- cost much more than to purchase an outfit to 100 Chemicals, Pure, with Apparatus per- VENTION and we 'will gladly answer ariv and the results would never be as good. If form many experiments -54.00 Prepaid. you would like to experiment. I would sug- 35 Pieces High -Grade Chemical Apparatus, question relating to home movies except those suitable for the experimenter-$5.00 Prepaid. that require a comparison of various prod- gest that you get some second-hand parts Money Order or C. O. D. ucts. Questions relating to the use of 9nini, and assemble them. This will eliminate the PINES CHEMICAL COMPANY 16mm or 35mm are all within the scope of delicate work associated with the film pull - 1524 St. Marks Ave., Brooklyn, N. Y. this department. Address your questions to down mechanism and at the same time would THE HOME MOVIES EDITOR, SCIENCE give you a better chance to turn out a work- Cut »ice AND INVENTION, 230 Fifth Avenue, New ing instrument. Two years' written OF FIREWORKS guarantee given with York, N. Y.) MOVIES thin fully jeweled im- pocket James J. Corona asks: pen -knifenifadannwith ad MAKING OWN CAMERA AND PROJECTOR it pictures of fire- ietol-shaped cigarette lighter. Q. Is possible to take f sigh -grade thin model watch combination white and green [old effect case, artis- Willis E. Broyda asks: works at night time? tically engraved, rich, elegant. Ac rate to timekeeper, tested, adjusted. Send no Q. Could you give me some information A. Yes, and without any addition your Money. Pay poetman$3.59a Igoe postage. of an amateur mak- equipment. That is providing you have a Jenkins, 621 Broadway, Dept. Mí1 regarding the possibility New York, N. Y. ing a movie camera and projector? (Continued on page 639) Please say yo u saw it in SCIENCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928 637

How Lindbergh's Famous Engine Was Manufactured By H. W. SECOR (Continued from page 591) writer saw and "heard" on test. "Heard" is correct. To more strongly impress this visit on the reader's mind, it should be mentioned that with this larger size engine the exhaust pipes. from the cylinders were not connected to the usual pipe manifold, but the exhaust from each cylinder shot directly out into the atmosphere. The blast of heat frorr the four -foot flame exhaust discharges f ram the nine cylinders was so intense that one had to practically run by the test room door opening, at a distance of thirty feet. One can also feel the breeze from these engines under test as they are /THIS is the electrical age, with unlimited opportunities for the man who hasedu- whirling round a spcial four -bladed club cated himself in the finer points of electrical practice. propeller, this prcpeller having been calibrated previously. This propeller acts as Fit yourself for one of the really big jobs by knowing electrical practice complete, a load for the engine, and also gives the including inside and outside work, central stations, and the whole subject. With the engines the necessary factors by which to aid of the Croft books you can know electricity as experts know it and put yourself measure the output of the engine at various in line for an expert's pay. speeds. The company building these engines is Flexlble also developing a new twelve cylinder 600 binding The Croft Library for easy horse-power "V" type airplane engine with air-cooled cylinders. This concern also builds Electricity°ndling a very powerful twelve cylinder marine of Practical engine for use in speed boats and launches. in reason why an inverted "V" type A reference library and self -training course Asked the volumes. 3000 pages -2100 illustrations engine was used, one of the engineers ex- eight plained that this was preferred to the up- The Croft Library contains three thousand pages, with twenty-one hundred of the clearest illus- right "V" type, owing to the greater visi- trations ever put into book form. Each of the eight volumes is indexed so that everything you want to know about electricity is at the fingers' ends. And when you find what you want, there is not merely bility afforded the pilot of the plane equipped a short question and a short answer. You are told everything you want to know. The explanation is with this type of engine. Knowing how clear to you, regardless of whether you have had a previous knowledge of electricity or not. easily some automobile engines become Croft teaches you electrical practice complete. He takes you in quick, easy steps from the simplest flooded with oil, without being inverted, the principles to the complete and economical operation of a great central station. inquired as to how the inverted "V" He tells you the things you need to know about motors, generators, armatures, commutators. writer transformers, circuits, current, switchboards, distribution systems-electrical machinery-wiring for engine overcame the oil flooding problem. light and power-wiring of finished buildings-underwriters' and municipal requirements-how to do One can imagine what would happen if we a complete job, from estimating it, to completion-illumination in its every phase-the latest and most took an ordinary automobile engine and improved methods of lighting-lamps and lighting effects, etc. turned it upside down. The cylinders would be filled with oil, and very shortly would THE STANDARD IN PRACTICAL cease to function without a doubt. This very interesting problem had been solved, it ELECTRICAL TRAINING oil was stated, by arranging two suitable Everywhere the Croft Library is acknowledged as the standard-the leader-in practical pumps, so that practically all of the bearings electrical training. It is the daily guide of 59,000 highly-paid electrical workers and engineers. are fed with oil under forced pressure, 5,j60o There is nothing like it in print today. It is the most complete. the best illustrated, the most ducts and pipes. In other words, carefully compiled, the most easily understood electrical library available. No matter how through croft much or how little you know of electricity, you will find the Croft Library a sound, helpful the oil is pumped through the engine bearing guide to greater accomplishment. system and withdrawn from any point of Every day you use these great books you will learn something that will help to make you accumulation as fast as it collects. a better electrical worker. Every page is taken from every -day electrical practice. Croft deals only with the kind of problems you meet in daily work. Own a set and join the 59,000 It is very interesting to note that when men who have found the Croft Library to be a real working companion to bigger accomplish- new or cylinder head, ment in the electrical field. Keep these books handy in your room. Put one in your pocket when you take developing a cylinder not interesting connecting rod, etc., for a given type of the car or train in the morning. Give them the odd hours. They are tiresome treatises, but as as any reading matter you ever owned. Consult your set regularly, acquire just one new fact a day, and in engine, that a whole set of nine cylinders a few years you will be a broadly informed electrical man. or other parts is not required in order to make a research test on the new metal or Success in Electricity new shape, as the case may be. In one of Easy Steps to the research departments, a provision is made Starting right in with the ABC's of modern what is needed to get ahead. He has poured out all electricity, Croft takes you through his books in his knowledge-all his experience-in language that for running and observing a single cylinder easy steps. He gives you the boiled -down records anyone can grasp. Yet the text is so scientifically with crankshaft and one connecting rod to- of every -day electrical practice in plain words, correct that thousands of the highest -paid electrical gether with one piston, etc. In other words, figures, and illustrations. Nothing is left to the engineers are using the books as a reference set, imagination-there is no guesswork. The famous set is beyond a doubt the last word the new part is tested in the form of a one Croft has been through the mill. His knowledge in practical electrical education. No one who cylinder engine. After running this for of electricity has been gained by actual shirt -sleeve wishes to get anywhere in the electrical field can a number of hours and carefully measuring contact with electrical problems. He knows just afford to be without it. the parts, as well a; testing them for strength r and chemical make-up, suitable engineering FREE EXAMINATION COUPON data is thus obtained and given to the chief Free Examination engineer. This saves a lot of time and McGraw-Hill Book Co., Inc., money, especially when many different metals 370 Seventh Avenue, New York. No Money Down - Gentlemen-Please send me the CROFT LIBRARY or shapes of certain parts are to be tested ! OF PRACTICAL ELECTRICITY (shipping charges and their merits cr demerits ascertained by 10 Months to Pay prepaid), for 10 days' free examination. If satis- the research expects. factory, I will send $1.50 in ten days and $2.00 per Fill in and mail the coupon attached and month until $19.50 has been paid. If not wanted, I PROCEDURE IN AIRPLANE ENGINE TEST we will send you the entire set of eight will return the books at your expense. (Write plainly volumes for ten days' Free Examination, and fill in all lines.) THE parts for the air-cooled engines \Ve take all the risk-pay all charges. You been finally assume no obligation-you pay nothing which have approved are unless you decide to keep the books. Then Name stored in bins adjacent to the assembly floor, $1.50 in ten days and the balance at the rate withdrawn and partially assembled at the of $2 a month. Send the coupon NOW and Home Address tables, and then finally used in building up see the books for yourself. the completed engine. Even at this point City and State the parts for an individual engine are subjected to careful scrutiny so that the finished Send the Coupon Employed by product may be as nearly perfect as is pos- Occupation SI -11-25 sible from the standpoint of fit, balance, etc. TODAY

P1ea.ce .r a\' t'n rt sn,c it in S( IE CE (7 II rl I\r r' r: .NT T 1 nY

www.americanradiohistory.com 638 Science and Invention for November, 1928

When finally assembled the engine is taken to the test .stands reserved exclusively for use in the preliminary test run. These CAMPBELL'S stands consist of a mounting for the engine, INFRA -RED RAY suitable instruments to take significant readings during the test, and a device known as a "test -club" which is mounted on the engine LAMP to absorb the horse-power output. These clubs are of the form of a four -bladed propeller and have previously been carefully calibrated so that the horse-power required to turn them at any given speed of revolutions is definitely known. When mounted on the stand the engine is first run-in. This consists of approximately five hours of running, starting at a speed of 800 r.p.m. and progressing by stages of 100 r.p.m., until a speed of 1750 r.p.m. is reached. The latter figure corresponds to about nine -tenths of the rated maximum horse-power of the engine and each successive speed is maintained for approximately one-half hour. The engine is next subjected to two hours of running at nine -tenths rated load (1750 6WEEKS AGO r.p.m.-180 h.p.) . Throughout this running significant read- Have You Some ings are taken and noted on the engine log Troublesome Ailment? he clipped sheet. You will be greatly surprised when you learn how Following this initial test the engine is Infra -Red Rays relieve congestion or troubles causing cleaned externally and completely disas- aches and pains in the body. The Campbell Infm-Red the coupon Ray Lamp concentrates a mild beam of Infra -Red sembled. The parts for one complete engine Rays upon any part of the body. Other fellows had left him in the social back- are laid out carefully on a double -decked These rays penetrate deeply into the tissues. As they him. He was missing table and are given a very careful inspection. penetrate they create an active circulation of the blood. ground. Girls avoided Most ailments are due to congestion-relieve the con- all the modern fun. Then, one day, he read Every part is examined for wear and nota- gestion and you relieve the ailment. Nature herself an advertisement. It held out a promise of tions are made on a standard inspection does the healing by active, normal blood circulation. popularity if he would only learn to play a sheet. After having been approved by the Why Suffer Needless Pain? inspector, the engine is reassembled of the If you or some one in your home have a troublesome ail- original parts and taken to the final test ment, a lamp like this is a blessing. May be used safely by anyone. Entirely unlike ultra-violet or X -Ray. Positively 'CfL' stand. During reassembly any necessary cannot sunburn or blister. parts Relieve bronchial trouble, Neuralgia Neuritis, Sinus minor substitutions of are made and trouble, Catarrh, head noises, Asthma, Ear trouble, Rheu- the valves are again carefully ground. matism, Hemorrhoids, Prostatis, Gall -Bladder, Tonsilitis, At final test stand another initial run- Lumbago and many other ailments with soothing Infra - GTrue crone Saxophone the Red Rays. ning -in is given which consists asbef ore of Let Us Send You He thought himself musically dumb. Still, the ad the easy stages of running. at successively said it was easy. He mailed the coupon, and later Our Book on Infra -Red Rays sent for a Saxophone for 6 days' trial. Before the higher speeds varying between 800 and 1750 We have an interesting book on the use of Infra -Red Rays end of the week he was playing easy tunes. That r.p.m. The total run-in in this case amounts which we shall be glad to send tree to any reader upon 'was 6 weeks ago, and today he's "popularity" itself. to about one hour of operation. request. Our book quotes leading authorities as well as 'Always welcome everywhere. users of our lampa Full directions for use, how to order, The engine is then run for one-half hour our home trial offer, etc., are also explained. You Can Do It Too! If You Try Infm-Red Rays have brought such wonderful results at nine -tenths rated power (1750 r.p.m.- for others you are sure to be interested. Write today for If you can whistle a tune you can master an easy 180 rated our book telling more about it. fingering Buescher Saxophone. 3 lessons, free on h.p.), and one-half hour at power request with each new instrument, teach scales in (1800 r.p.m. 200 h.p.). In both these runs THE WILLIAM CAMPBELL COMPANY an hour and start you playing popular tunes. the fuel and oil consumption are carefully 1050 Union Avenue Alliance, Ohio Six Days' Trial, Easy Terms checked and no engine is approved unless ,Try any Buescher Saxophone, Cornet, Trumpet, these readings are within specifications. The 'Trombone or other instrument in your own home specified maximum fuel consumption is .55 six like little 'for days. If you the instrument, paya lbs. h.p. hr., and the corresponding figure each month. Play as you pay. Mail the coupon for 68 Miles on 1 Gallon of Gas beautiful literature and details . of this wonderful for oil consumption is .025 lbs. h.p. hr. trial plan. Make this start. Now. A reading of maximum power delivered (Affidavits on File) with the carburetor adjustment at both full 5 This Simple Device Can Be Buescher Band Instrument Co. rich position Everything in Band and Orchestra Instruments and the setting of best economy Installed on All Cars 2602 Buescher Block Elkhart, Indiana is then taken. An idling test is then run, consisting of -7 AGENTS- $250 BUESCHER BAND INSTRUMENT CO. (304) five minutes of operation at approximately Ifilli!I Make to $750 2602 Buescher Block, Elkhart, Ind. a Month Gentlemen. Without obligating me in any way, please 300 r.p.m. This test is carried on to assure send me your free literature. Mention instrument smooth operation at all engine speeds. $15.00 a Day Guaranteed interested in. to Producing Distributors Finally an acceleration test is given. With Age's Name instrument the engine idling at about 300 r.p.m., and Trial Costs You Nothing Name the carburetor properly adjusted, the throttle Send quick for Proof and big money -making proposition. Address is suddenly opened the maximum amount. .Jl No engine is accepted unless an immediate Get FREE Tire Offer response is noted. Write for Full Information In the event that all these tests have been Blancke Auto Devices Co., 154 E. Erie St., Dept. 863-P.B., Chicago (ALL STAN iRDR'rE'Rings passed successfully, the engine is then cleaned O and made ready for shipment. If, however, any major part, such as a piston, master rod ®r 3 DAY S bearing, cylinder, cam, etc., is replaced on 'Round the World with New disassembly, what is known as a "penalty Karas Short - Wave Receiver I2 PRICE rFTRIALREE test" is carried out in addition to the regu- Enjoy the hearing stations thousands Your choice of the Just send your name lar procedure. This test is made previous thrills of World's best type- and address for com- of miles away. Karas engineers have developed plete FREE CATALOG to the final testing outlined above and con- writers - Under- LNow ib- short-wave equipment to highest point. Easy to wood, Remington ingpanid'showiing pb to- sists of a one -hour run-in at nine -tenths build. Easy to tune with Karas Micrometric Royal, etc. full grepbe of encb besutt- dials. 63 to 1 ratio. Uses Karas condensers, - fui machine In full col rated horse-power, which the engine size, late model, after a fine completely rebuilt ors. Tells every detail built like watch. Karas coils and audios- of one direct - to - yon is sufficiently disassembled to determine the standard of the world. Send today for complete and refinished brand timid ment plan. new. Prices smashed Write ówyfor trem ea- condition of the part replaced. All being information and construction blueprint. Free. to half. Act quick. dous saving. Still time in order the final proceeds Send no money. If you act now. testing as outlined. KARAS ELECTRIC COMPANY INTERNATI O NAL THEN qCA 184 W. Lake St. The results obtained from such procedure 4049L1 -North Rockwell St.. Chicago, Ill. TYPE. EXCHANGE ONLY le DAY Dept. 1117 Chicago are accurate to approximately plus or minus 2 per cent, and to assure the power output Name of production engines does not vary from THIS CLASS PIN 3Óc. St. and No you if buy 12 or more, Silver piste. singly 40c ea choice of 4 these figures one of every five engines is colors enamel, 8letteredi date. Sterling Silver, 12 or more 60, City and State . given its final on a Singly 60c en. Big Free Cat. shows Emblem. 25c to $8 testing dynamometer, es. 4049I 1 685 METAL ARTS CO.,I.e., 863 Penland Ave., Rochester,N.Y. where precise readings are possible. Please say y on saw it in SCIENCE and TNVENTION

www.americanradiohistory.com 639 Science and Invention for November, 1928

HOME MOVIES (Continued from page 636)

r SPLICE HERE

FILM ' r^ THIS PART OF TAKEN BY HOLDING i CAMERA UPSIDE DOWN Book THIS Trough 1 AND REVERSING and ( SECTION AFTER Magazine DEVELOPMENT Stand See LePage's Old Salem Ship's Cupboard Boolc,page 19 See LePage's Book, page 5 How to make your own Cw SPLICE HERE Household Furniture How People in any scene can be made to move LePage's Latest Book Shows backwards by holding the camera upside- Yourself; for Christmas Gifts down and splicing the film as shown. -for LePage's latest book, the new "Third Home Work Shop lens at least as fast as F 3.5. An F 1.9 Book," contains complete, easy -to -follow directions for making QO pieces of household furniture, of lens is even better, but with panchromatic attractive 17 are entirely new and never offered before. film, and no filter, you should get good pic- which if fairly close to the display. All red This year the designs are divided into three groups. tures One group is based on famous old Colonial pieces. or all green will not affect the emulsion very suggest that you double Another group follows the furniture in popular demand much and I would for American homes of today. The third group is known and triple expose your scenes. To do this, back the film by as modernistic furniture, showing the influence of the after making a shot, turn modern skyscraper set -back architecture of New York opening the camera in the dark and unthread- roll as the City. To buy 20 such pieces would cost about $1,000. ing. It is best to start a fresh can make for a fraction of yet be the a guide. You them that, paper leader will serve as of truly fine furniture. Niagara Falls and similar all -white dis- owner plays should be photographed from such a Designed by Expert distance that some of the dark background drawings, pieces will be included in the scene, otherwise the All the designs, dimension actual and Modernistic Folding Screen photographs were made by William W. Klenke, Instructor film will be solid white with little to relieve See LePage's Book page 12 the monotony. Fetter stop down half a in Woodworking, Central Commercial and Manual Train- on these all -white displays. When ing High School, Newark, New Jersey. Also the designer point too, 12 the first two LePage's Books. Each project and the taking a display that is all in colors, slow NEW of a trifle, to about twelve directions for making it are perfectly practical. the camera down Job Plans, Too! is photo- per second. If your camera is Each project presented in three parts-a exposures graphic illustration of the finished project, a complete not adjustable, open wide and trust to luck. There is, of course, a limit to what we can give in LePage's New Third Home Work Shop dimension drawing of its parts, and simple, easy -to- Book for only a dime. But we realize many men follow, step-by-step directions. want additional projects. Hence our 12 new shown tl e Look Job Plans. These also were made by Mr. In addition to the three pieces above, Klenke. They are projects that require more includes the following: Cape Cod Chest of Drawers, Photoplay Review elaborate presentation than we can give in our Alexandria Nest of Tables, Lady Washington Sewing book. Each Job Plan presents one project on Modernistic Book Shelves, Desk, Table, and issue, SCIENCE AND INVENTION a single large sheet of paper. Each is well Cabinet, With this China or a new feature as a part of the HOME worth its price, one dime. Look over these Fire Screen, Smoking Table, Caned Side Chair, starts projects and order those you want by number Book Cabinet, Magazine Carrier, Vanity Case, Book MOVIES Department. Each month we will (see coupon), enclosing 10 cents for each. pictures that Stand, Fernery Stand, Folding Sewing Screen, Plymouth present a review of one or more 16 Sheraton Writing Desk Table. from a technical viewpoint, Built-In China Closet, and Chess and Checkers are outstanding 17 Sheraton Desk Chair Where else could you get complete directions for making cast not receiving mention ini- Shelves the story and 18 Colonial Hanging Book all these for only 10 cents? less because of exceptional merit. 19 Smoking and Read- reviewed here have been studied ing Cabinet The films 10 for NEW LePage's with the amateur foremost in our minds. 20 Colonial Mirror Lr PAGE'S Send cents this of 21 Tea Wagon THIRD Book IVe will try to point out the features HOME Home Work Shop 22 Telephone Cabinet each picture that are of special interest to WORK SHOP it to us with 10 23 Stool for Tele- BOOK Simply use the coupon below, sending the amateur and, when space permits, will cents in coin or stamps, and we will at once send you a describe any special features or tricks. phone Cabinet 24 Manual Training copy of this latest LePage's Book, postage paid. WHITE SHADOWS IN THE SOUTH SEAS Work Bench 25 Home Worker's MAIL THIS COUPON "White Shadows in the South Seas" Tool Cabinet LePage's Craft League (Metro -Goldwyn -Mayer) is one of the most 628 Essex Ave., Gloucester. Mass. 26 Spanish Galleon Gentlemen: Enclosed please find 10 cents (coin or stamps) in interesting and educational pictures that it 27 Vanity Table for New 'ThOrd Home Work Shop Book. has been our privilege to watch. It was Peament se send a opyagt st is book made in the Marquesan Islands, with an al- Name...... most 100 per cent native cast and is there- Street motion picture. It fore almost an amateur State shows what can be done with amateur actors E AG E'S euv Please also send the following Job Plans when the direction is competent. The pho- ber those ou want. at left), for tography throughout is perfect, panchro- GLUE ea h oft which I enclose an additadditional 10 centsumn (Continued on page 666) HANDIEST TOOL IN YOUR WORK SHOP Please say you saw it in SCIENCE aid INVENTION

www.americanradiohistory.com 640 Science and Invention for November, 1928 PATENTS TRADE-MARKS-DESIGNS 9.______y:+,> .,y,sYy.-,.,.1,,,._ ..F FOREIGN PATENTS Of? '111,2' , MUNN & CO. PATENT ATTORNEYS Associated since 1846 with the CONDUCTED BY JOSEPH H. KRAUS Scientific American In this Department we publish such matter as is of interest to inventors and particularly to those who are in doubt as to certain patent phases. Regular inquiries addressed to "Patent Advice" SCIENTIFIC AMERICAN be answered by mail free of charge. Such cannot BUILDING inquiries are published here for the benefit of all readers. If the idea is thought to be of importance, we make it a rule not to divulge all details, in order to 24 West 40th Street protect the inventor as far as it is possible to do so. Should New York City advice be desired by mail, a nominal charge of $1.00 is made for each question. Sketches, and descriptions must be clear and explicit. Only one side of sheet should be written on. SCIENTIFIC AMERICAN NOTE :- Before mailing your letter to this department, see to it that your name and address are BUILDING upon the letter and envelope as well. Many letters are returned to us the inquirer or his because either the name of Washington, D. C. address is incorrectly given. TOWER BUILDING DEMOUNTABLE RIM these blocks, Chicago, III. the chance of a dangerous accident is (1130) Mark A. Hutton, Kingston Springs, Tenn., more than possible. We certainly advise no action HOBART BUILDING has advanced the suggestion for a new demount- along this line. San Francisco, Cal. able rim for automobiles and requests our advice on the same. . PHONOGRAPHIC SIGNAL REPRODUCER VAN NUYS BUILDING A. 1. The suggestion which you have advanced (1134) Toseph N. f.ahovsky, Wilmington, Del., Los Angeles, Cal. for an auto wheel rim is by no means new. This asks our opinion of a "talking" horn to repeat same idea has been previously tried, and even any signal desired. Books and Information on Patents and though found practical, has not met with very A. 1. Many years Trade -Marks By Request ago manufacturers made talk- great approval. ing dolls and talking horns for automobiles. It Associates in all Foreign Countries There is one objection to the method as out- seems that people do not care for devices of this lined, in that the flange slides over a portion of nature, except as novelties. In the talking doll the rim. This is quite a poor method because a drum record was used, having about ten lines of rust or dirt getting in on this surface makes it voice on this circular record. In the talking horns almost impossible to separate the rim. The best for automobiles, a metal record was used, which method of approach is the system now used on repeated the same thing over and over again. the wheels of an automobile. We are doubtful that you can do anything with HAIR the idea, and advise no further action. CLIPPER (1135) George Girard, Elmhurst, L. I., asks VERTICALLY whether we think there is a market for a self -hair INVENTORS RISING PLANE cutting system. (1131) Henry- Cloutier. New fork City, has de- A. 1. There are many methods of cutting hair signed an airplane which he claims will rise which the individual himself can employ. One of Protect Your Ideas vertically if perfect balance can be maintained. these consists of a safety blade attached directly IIe asks our opinion. to a comb and by combing the hair one can trim A. 1. There are a great many inventions on his own hair. The operation is smooth and simple. Send for our Guide Book, HOW the market along the lines of vertical rising air- TO GET A PATENT, and Evidence One-man hair clippers were also put on the market planes, some of which have proven themselves to and many other means for giving oneself a hair of Invention Blank, sent Free on be highly satisfactory. If the airplane you have cut have been tried, yet none of them have been request. Tells our terms, methods, designed requires that it must be perfectly bal- even ordinarily successful. We certainly advise etc. Send model or sketch and anced at all times in order to give a good rise no action along this line. description of your invention for or in order to maintain equilibrium in the air, si e' would advise no further action. Perfect INSPECTION and INSTRUCTIONS stability TEMPERATURE WINDING CLOCK FREE. TERMS REASONABLE. in any form of airplane will at all times be non- existent, just tite same as it will be impossible (1136) Nathan I -I. Brachmau, Dayton, Ohio, re- BEST REFERENCES. to ever develop a ship which can never roll or quests our information on a clock which shall be bob tip and down on the waves. daily wound by changes in atmospheric temperature. He mentions no specific design, but wants RAINCOAT to know if he can patent the system. A. 1. There are, we believe, quite a few pat- (1132) William Girard, Lawrence, Mass., asks ents covering the mechanisms for automatically RANDOLPH & CO. our opinion of a raincoat designed to prevent winding clocks by expansion of liquids (xylene water getting on the feet 172, D. of the wearer. generally employed) and by expansions of me- Dept. Washington, C A. 1. We do not think that the suggestion for tallic bars. a raincoat back which you have designed is a SCIENCE & INVENTION Magazine many very practical idea. In certain respects it re- months ago illustrated a perpetual clock built in minds us of invention Name the of a raincoat which France, which had a piston operating within a liad a gutter at the bottom and a spout project- cylinder, which piston wound ing from up the clock the side thereof to prevent the water through a rack arrangement. A far better method from getting on the feet. Street than this is the system utilized in the Motoco All this could be overcome by simply increas- indoor -outdoor thermometer and in the distant ing the length of the raincoat or extending it at temperature registering the base, making means. In these systems the coat act as a perfect shield liquid is placed within a tube which City for the feet. connects directly with a coiled flat tube made of rela- We are doubtful that the ribbed construction tively thin material. Any pressure will prevent wet feet. exerted in the liquid has a tendency to open this spirally - coiled tube. At the same time there is no leak- SKID PREVENTER age of pressure or loss of liquid. This system (1133) Ernest Makonsky, Send details of your in- Hoboken. N. J., has could easily be used to wind a clock spring. vention or patent at once, designed a system for preventing skidding of an We do not believe that a patent will be of any automobile. INVENTORS or write for information. Ilis method consists of having ar- value whatever unless you can develop a satis- In business 30 years. ranged on a system of levers forms of wedges. factory system. Complete facilities. References which, by the operation of a controlling device, ADAM FISHER MANUFACTURING COMPANY are driven beneath the wheels and in contact with 203D Enright, St. Louis, Mo. the road. He intends in this way to prevent the GAS MOTOR VALVE skidding of an automobile by the increased fric- (1137) T. S. Dayton, Gilmore, Iowa, submitted tional contact with the road. an idea for a new form of valve for automobiles A. 1. The method for stopping an automobile to be substituted for the present ports, which is and for apparently preventing that automobile from in the form of a cylindrical tube and rotates to NEW YEAR - NEW IDEA skidding as indicated in your recent communica- open and close the ports. PATENT YOUR IDEAS tion, is in our opinion entirely impractical. In- A. 1. The suggestion which you have advanced equalities in the road -bed for an is Ile Call or send me a sketch of prevent the particular automobile valve not new at all. A Pitone LONgacre 3088 blocks which you intend to suppress motion from great many patents have been taken out on this your invention. making contact with road the wheel. saute idea, and Recordingvice Blank the and with an engine employing this system FREEInvontldenentorstC lal Ad It is apparent then that if any one of these blocks has actually been built, tried, and found quite U. S. and Foreign Patents secured by does not properly create a friction on the road- successful. bed, the tendency of the automobile to skid will It is extremely doubtful that you could do any Z.H.POLACHEKCo ult. Engineer II be even greater than today. If a projection were more with the idea than has already been done. BE 1234 Broadway, New York to rise up from the road and encounter one of We consequently advise no further action. Please say yon saw it in SCIENCE an d INVENTION

www.americanradiohistory.com Science and Irvention for November, 1928 641

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All drawingsand spec. My Patent Law ifications are prepar. Offices ed under my personal Just Across Street supervision. From U.S. Pat. Office

Protect Your Ideas Take the First Step Today-Action Counts If you have. idea for Inventors a useful, practical, novel for any new article or an improvement on an old one, you should communicate with a competent Registered Patent Attorney AT ONCE. Every year thousands of applications for patents are filed in the U. S. Patent Office. Frequently two or more applications are made for the same or substantially the same idea buefit-theg, (even though the inventors may live in different sections of the country and be entirely unknown to one another). In such a case, the burden of proof reata upon the last application filed. Delays of even a few days in filing the application sometimes mean the loss of a patent. So lose no time. Get in touch with me at once by mailing the coupon below. Free Boo Prompt, Careful, Efficient Service This large, experienced organization devotes its entire time and attention to patent end trademark cases. Our offices are directly across the street from the U. S. Patent Office. We understand the technicalities of patent law. We know the rules and requirements of the Patent Office. We can proceed in the quickest, safest and best ways in preparing an application for a patent covering your idea. Our success has been built on the strength of careful, efficient, satisfactory service to inventors and trademark owners located in every state in the Union. Strict Secrecy Preserved-Write Me in Confidence All communications, sketches, drawings, etc:, are held in strictest confidence in strong, steel, fireproof files, which are accessible only to author- ized members of my staff. Feel free to write me fully and frankly. Your case will have my personal attention. It is probable that I can help you. Highest references. But FIRST-clip the coupon and get my free book. Do THAT right now. No Charge for Information On How to Proceed The booklet shown here contains valuable information relating to patent procedure that every inventor should have. And with it I will send you my "Record of Invention" form, on which you can sketch your idea and establish fts date before a witness. Such evidence may later prove valu- CLARENCE A. O'BRIEN able to you. Simply mail the coupon and I will send you the booklet, and Registered Patent Attorney the "Record of Invention' form, together with detailed information on how 53-G Security Savings & Commercial Bank Bldg., to proceed and the costs involved. Do this NOW. No need to lose a Washington, D. C. minute's time. The coupon will bring you complete information entirely, without charge or obligation. Please send me your free book, "How to Obtain a Patent," and your "Record of Invention" Clarence A. O'Brien form without any cost or obligation on my part. Registered Patent Attorney Member of Bar of: Supreme Court of the United States; Name Court of Appeals, District of Columbia; Supreme Court. District of Columbia; United States ourt of Claims. Address PRACTICE CONFINED EXCLUSIVELY TO PATENTS, TRADEMARKS AND COPYRIGHTS (Important: Print or Write name clearly)

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www.americanradiohistory.com Science and Invention for November, 1928

Is Civilized Man Losing His Sense of Smell? By UTHAI VINCENT WILCOX (Continued The front page 600) FUTURE "Smell," he stated, "seems topbe the chief factor on which the social life of a bee colony is founded. A new hive odor is formed when colonies are united and the by foreign hive odor is eliminated when queens are introduced. Knowledge of bee -odors Professor A. M. Low Washington Monument in the Nation's Capital helps in catching swarms. The absence or presence helps of the queen -odor to tell "THE FUTURE" is one whether is of the most PATENTS or not a colony queenless and remarkable books of the age. Professor aids in locating lost queens." DON'T LOSE YOUR RIGHTS Low, the author, is a scientist of interna- BEE'S KNEES tional reputation, also an experimenter TO PATENT PROTECTION and inventor in the many branches of Before disclosing your invention to science. This book written by him has anyone send for blank form "EVIDENCE AFTER months spent in studying this OF CONCEPTION" to be signed and wit- insect, in the hives and under a high- aroused wide -spread interest. It deals nessed. As registered patent attorneys we powered microscope in his laboratory, Dr. with the world of the future, certainly an represent hundreds of inventors all over Mclndoo paused in his unusually absorbing subject. Written in the United States and Canada in the ad- investigations to vancement of inventions. The form make this announcement to the scientific the popular, non -technical fashion, "The "Evidence of Conception," sample, in- world : Future" reveals the many advances and structions relating to obtaining of patents "It's the bee's knees." changes that are in store for humanity in and schedule of fees sent upon request. He was not trying to be funny. He had a new life to come. This book LANCASTER & ALLWINE discovered that the olfactory glands, or, has received favorable com- one might say, nose, of the bee are prin- ment in book reviews the world over. Do 255 Ouray Building cipally located in his knee joints. To the not neglect to read this treatise on the WASHINGTON, D. C. layman such detailed studies of the insect's future by Professor A. M. Low. It is a Originators -of forms "Evidence literary treat for everyone. of Conception." sense of smell may seem pointless, but to the scientist and to the scientific farmer the findings Mail your order now! Don't wait, every- are highly important, leading body is reading this remarkable to the control of destructive pests and the book. consequent saving of millions of dollars. How this is accomplished will be explained Price-$2.00 later. 300,000 Experimenter Publishing Co. Pierre Loti, in Madame Chrysantheme. For This Invention 230 Fifth Ave., New York, N. Y. makes mention of "a strange odor, mingled Gentlemen: Enclosed find check or money That's what Eastman Kodak P aid with that of lotus and musk ; an intimate order (check which) for $2.00. Kindly send me a for the Autographic idea. Thousands odor of Japan, copy of Prot. A. M. Low's new book "THE FU- 0 f otherh inventions are needed and of the yellow race, which TURE." offer enormous opportunities for earn- rises from the soil and emanates from an- ing fortunes. If you are of an inven- cient wainscotings." Another writer re- Name tive turn of mind why not concentrate on things that marks races are really NEEDEDI Get Raymond Yates's new book, that the different have charac- Address.. . teristic odors ; that, while the African native City State 1,000 Needed Inventions has a disagreeable odor to the European, Costs only $1.25 and may_ start you thinking along the right lines. You'll get nowhere lust fussing around. Con- the European is still more offensive to centrate on what the industries need, and on what the public wants. Mr. Yates's-book tells you what these things are. Japanese nostrils. It is Said that certain Send no money. Just write postal. Pay mail man $1.25 English people have been able to recognize, plus postage when book arrives. Your money back if you Want it. This offer limited. Write now and get on the not only different races, but different persons right track. Outside U.S., $1.45 cash with order. Address by smell. 711 Wisner Bldg. Bureau of Inventive Science Rochester, N. Y. tto'beautiful proportions while you sleep! PATENTS A11ITR 110SE ADJUSTER WRITE FOR FREE INSTRUCTIONS is SAFE, painless, comfortable. Send drawing or model for examination. Speedy, permanent results guar- CARL MILLER, Patent Attorney anteed. Doctors praise it, No Former member Examining Corps, U. S. Goldmedal metal to harm you. Small cost. Patent Office Won 1925 Write for FREE BOOKLET 8IroRt.oei R. 261 McGill Building, Washington, D. C. ANITA INSTITUTE, 1173 Anita Bldg.,Newark, N.J.

WAY As one of the oldest patent EASY S firma in America we give to Inventors at lowest consis- Make Money PATENTS tent charge, a service noted gN RA1D1O for results, evidenced by many well-known Patenta of extraordinary value. Book, Patent-Sense, free. Reducestatic-electrify old seta-improve tose-install I -dici control radiofy o Lacey & Lacey, 644 F St., Washington, D. C. Estab. 1869 ersybe-make $3.00 en hoar seem tlm by laini r the Radio Amoeiation. Our member issuing o Writs toda for No-Co.t Mem- bar,bi a FREE RADIO HANDBOOK. RADIÓ ASSOCIATION OF AMERICA De t.SN114513 Ravenswood Av.. Chicazo i PATENTS BOOKLET FREE HIGHEST REFERENCES BLUE BOOK ON PATENTS PROMPTNESS ASSURED BEST RESULTS and Priority Record blank gratis. Send drawing or model for examination Bees know their own hives by a peculiar MONROE E. MILLER, PATENT LAWYER. and advice. sense of smell. It is the bee's knees which 411-6 Ouray Building, WASHINGTON D. C. WATSON E. COLEMAN, Patent Lawyer give forth the characteristic odor. ELECTRICAL AND MECHANICAL EXPERT 724 9th Street, N. W., Washington, D. C. Dr. Mclndoo, pursuing his study of odors, has concluded that in civilized man SQUAB BOOK rA FREE MACHINE SHOP the sense of smell is most highly developed FOR GENERAL AND EXPERIMENTAL WORK Breed squabs and make money. Sold by millions. Expert Mechanician in Electrical and Machine Work of all in the blind, and cited the instance of a Write at once for free 40 -page book beautifully Kinds. Models, Light Manufacturing. Established since boy, James Mitchell, born deaf, dumb and printed in colors telling how to do it. You 1878. Paul Hoenack, 108 Park Row, near Chambers trill be surprised. rtTMODU ROCK MKS CO. Street, New York City. If it's mechanical, we make it. blind, who depended chiefly upon this faculty 5O6 H St., Melrose Highlands, Maine Plea.te say y on saw it in SCIENCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928 for keeping in touch with the world. He readily observed the presence of a stranger in the room and formed his opinions of persons through this sense alone. Another writer tells of an English acquaintance who declared that to her the odorous atmosphere of a person is as characteristic and unmistakable as the play of the features or the carriage of the figure. FOOTECTIONTHE OUR OFFER: OFR YOUR PRINVENTION YOUR FIRST STEP. The inventor should write for our blank form-"RECORD OF IN= VENTION." This should be signed, witnessed, and returned to us, together with model or sketch and description of the invention for INSPECTION and ADVICE FREE! Our FIVE Books Mailed Free to Inventors Our Illustrated Guide Book HOW TO OBTAIN A PATENT Contains full instructions regarding U. S. Pat- ents, Our Methods, Terms, and 100 Mechanical Movements illustrated and described. OUR TRADE -MARK BOOK Shows value and necessity of Trade -Mark Pro- tection. Information regarding Trade -Marks and unfair competition in trade; A deaf, dumb and blind boy made his impression of various visitors dependent directly upon his sense of smell. OUR FOREIGN BOOK It is true that dogs identify people in this We have Direct Agencies in Foreign Countries manner and even objects they have lightly and secure Foreign Patents in shortest time and touched. In view of this fact it is not diffi- at lowest cost. cult to imagine that a person, in whom the sense is acutely developed, might be able to do the same. The skin constantly exudes PROGRESS OF INVENTION the products of body metabolism, the build- Description of World's Most Pressing Problems by ing up and breaking down of countless tiny Leading Scientists and Inventors cells, and these products differ in each indi- All Communications and Data Strictly Confidential. vidual, no two being alike, giving rise to Interference and Infringement Suits Prosecuted. various chemical odors. Exploitation of the sense of smell and the classification and advancement of knowl- DELAYS ARE DANGEROUS edge regarding it would result in the unfold- ing of a new world of experience and would IN PATENT MATTERS prove of intense sc,entific and economic value, Dr. McIndoo 'relieves. He points out that the senses of sight and hearing already To have been made the subject of intricate in- IMPORTANT! Avoid Delay! vestigation and that their stimuli, light YOU SHOULD HAVE YOUR CASE MADE SPECIAL IN OUR waves and sound waves, have been accu- OFFICE to save correspondence, secure protection and early rately measured and analyzed. Intellectual filing in Patent Office. To secure special preparation curiosity regarding the nature of sound has date the resulted in the telegraph, telephone, micro- of your case send $25.00 on account with model or sketch and phone and radio ; and, in light, in the micro- description of invention. scope, telescope, photographic camera, mov- Our Lawyers Practice in all U. S. Courts and defend Clients in Suits involving ing picture machine, the discovery and use Patents, Trade -Marks and Copyrights of ultra-violet rays and X-rays. In spite of the fact that, as far as knowl- OUR ORGANIZATION OFFERS PERSONAL SERVICE edge of the sense of smell is concerned, "we are still living in the Dark Ages." in- By Experienced Patent Lawyers, Solicitors and Draftsmen formation that has been gleaned, and has We regard a satisfied client as our best advertisement, and furnish, upon been used to great advantage, Dr. Mclndoo request, lists of clients in any state for whom we have secured patents. stated. Here are some instances: Highest References-Prompt Service-Reasonable Terms HOW SOME MAKE USE OF SENSE anWRITE TODAYm OF SMELL CHARACTERISTIC odors are associ- FREE ; VICTOR J. EVANS & CO ated with certain diseases, and the phy- COUPON Registered Patent Attorneys sician is using his nose as well as his eyes ' and ears in diagnosis. Chemists use the .. MAIN OFFICES: 715 Ninth St., Washington, D. C. olfactory sense as a help in analysis; bac- teriologists identify cultures by their odors, BRANCH OFFICES: 1007 Woolworth Bldg., New York City; 518-519 Liberty and plumbers use their. sense of smell in Bldg., Philadelphia, Pa.; 514 Empire Bldg., Pittsburgh, Pa.; 1114 Tacoma Bldg., locating leaks in boilers and pipe lines. The Chicago, Ill.; 1010 Hobart Bldg., San Francisco, Calif. procedure in the latter case is to force Gentlemen: Please send me FREE OF CHARGE your books as described above through the pipes water or air that has been mixed with peppermint oil or wintergreen, Name then smell at the cracks and joints. Or catnip oil can be used and a kitten be dele- Address gated to do the stuffing. 151 ma am ...... mi M. Please sa',' you cazo it i 11 SCIENCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928

The scientist finds, moreover, that it is literally true that "our lives are often saved by our. noses." The sense of smell, he explains, alone warns us against certain poisonous gases and manufacturers of illuminating gases, which are odorless, add odorous Get Your Copy of impurities to them, to decrease the danger of asphyxiation through carelessness. Other gases, not harmful in themselves, warn against dangerous conditions. Coal gas indicates the presence of deadly carbon monoxide, which has no odor, and sewer gas POPULAR warns against unsanitary conditions which may menace health. Next to the perfume industry, perhaps CARD TRICKS You Can Earn the most important practical application of smell is to be found in economic entomology, the control of insect pests through knowl- $ISO to $300 edge of their respective likes and dislikes By Walter B. Gibson in regard to odors. This knowledge has MONTHLY been gained haphazardly, by the laborious trial and error method, due principally to Charging Batteries in 8 Hours the fact that the insects' preferences are so Pleasant Entertainment For All Start a Money -Making Business of your own. Mechanics. different from those of a human being that Filling Stations. Repair Shops, Garages and Battery Stations the are all making BIG MONEY with HB 8 Hour Battery Ser- entomologist's own sensations cannot be vice: Recommended by the leading -car and battery makers. followed as a guide. But once the odor has Constant Potential lets you give a better charge than the Walter B. Gibson has written trier fellow in one-third the time, and at a saving of 30" been found which allures the ant or locust or to 50'" on current. Anyone can operate. Check coupon other insect, the scientist exploits it as what is conceded to be the below for information on how to get started in this monet - a making work. bait and mighty is the slaughter. 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BM 1130 Imagine HOBART BROTHERS, Box 5718, Troy, Ohio. Send me complete information on the items I've checked- the fun you can have at a : our thirty -day trial offer-easy payment terns-in- ODORS AS BAIT formation on how HB equipment will increase my earnings. party. Just nonchalantly D HB 8 HOUR BATTERY CHARGER AMONG insects which have responded O HB TEST BENCH to such poisoned HB PAINT SPRAY baits are the Argen- pick up a deck of cards and HB AIR SERVICE tine ant, which in 1922 "took" the State of Name Mississippi ; the grasshopper, against which inquire if anyone has "seen war was declared in western Canada in ddress 1921, with the result that 2,400,000 acres this one." Then, while all of crops were saved in one province alone; attention is focussed ai1d the olive fly, worst enemy of Italy's on you, great olive groves. Experiments are now do these tricks one after an- in progress to find an odor which will at- SET BUILDERS tract the codling moth, which ruins apples, other to the admiration and and the enormously devastating Japanese Write us for new illustrated beetle. wonderment of all. Catalog "D-1," containing all Attractive baits have been successfuly em- the new and popular kits in ployed even in controlling animal prey. A radio. Our tremendous stock en- member of the U. S. Biological Survey, ables us to give you immediate accidentally discovered that lions like the service on all radio supplies at odor of catnip just as well as kittens, and 25c wholesale prices. oil of catnip has been effectively used to THE COPY bait lynxes, bobcats and mountain lions in Western States, where they destroy, annu- ally, livestock and game AT ALL NEWSSTANDS OR Allied'Radio valued at from WRITE DIRECT CORP RATION $20,000,000 to $30,000,000. 711 W. LAKE STREET, CHICAGO In view of the rapidly increasing value to science and industry of an accurate ILLINOIS COLLEGE OF PHOTOGRAPHY EXPERIMENTER PUB. CO., INC. knowledge of odors and the sense of smell, Prepares you In from 6 to 8 months to earn $200 to $500 a month as a photographer or photo-engraver. Thorough Dr. Mclndoo strongly urged greater co- 230 Fifth Avenue, New York, N. Y. practical training. Expenses low. Qanstant demand for our graduates. 35th year. Enroll Unmedlately. Free operation among men in all branches of catalog.-Box 7118, Effingham, Illinois. science to increase the fund of information. Please s -ay y ou saw it in SCIENCE and INVENTION

www.americanradiohistory.com Science and invention for November, 1928 45

THE NEGLECTED SENSE GOOD work," he stated, "has been 48 V done, but not enough; and enough will not be done until there obtains a lively and wholesome curiosity about these two neglected sense;, smell and taste, which in reality must be studied together. "Consider what illuminating results are now available from researches in some of the other senses. To illustrate the comparative attention devoted to the different senses, one need only open the Encyclopedia Britanica. In the last edition, dated 1926, over thirty-two pages are devoted to sound, seventeen and a half to light, and four to touch, but only a page and a half each are given to smell and taste. "The authors of this storehouse of knowledge have either carelessly overlooked the recent information on all the five special senses, except hearing in the heading "sound," or they consider it of too little merit to be published." Dr. Mclndoo is by no means the only scientist who has advocated research along these lines in the belief that studies would lead to the founding of a new science. Among others who have realized the importance of such work was the late Alex- ander Graham Bell, who said: "Why not measure a smell? Can you measure the difference between one kind of Kansas saves Twenty Years smell and another ? Until you can measure their likenesses and differences, you can have no science of odors. Find out what An Advertisement of the an odor is-whether it is an emanation, and therefore capable of being weighed, or American Telephone and Telegraph Company a vibration, and therefore capable of being reflected. Odors are becoming more and more important in the world of scientific experiments and in medicine, and the need of more knowledge will bring more knowl- MORE than three hundred calls made in Kansas in 192'7 edge, as surely as the sun shines." studies are being carried on an average reduction of a constantly by the research, minute und a half was made engineering and business on each call - a total of staffs of the American Telephone and twenty years saved. MODEL BLUEPRINTS Telegraph Company and the associ- These more than three hundred Correct-Easy to Follow ated companies of the Bell System special studies have as their goal to accomplish definite improvements definite improvements in local, toll 1-2 Horizontal Steam En- gine details set $1.00 in telephone service. and long distance service. It is the 3-4 B Diler construction for In 1927 the number of local calls policy of the Bell System to furnish above set $1.00 not completed on the first attempt the best possible service at the least 5 8E0 Ton Bark 50e was reduced by 5 per cent. This cost to the user. 6-7 Twin Cylinder Steam means the better handling of 200,- The American Telephone and Tele- Engine and Boiler. set $1.00 8-9 Gasoline Fired Loco- 000,000 calls a year. graph Company accepts its respon- motive set $2.00 In 1926 the average time of sibility for a nation-wide telephone 10-11 U. S. S. Constitution, handling toll and long distance calls service as a public trust. It is funda- "Old Ironsides" set $1.00 was 2 minutes. In 1927 this aver- mental in the policy of the company Man -of - 12 13th Century age was reduced to i f2 minutes, that all earnings after regular divi- War 50e 13-14 Chinese Junk set 50e with further improvements in voice dends and a surplus for financial 15-16 Electrically driven transmission. security be used to give more and Automobile set $1.00 On 6,820,000 long distance and toll better service to the public. 17-18 How to Build a Re- flecting Telescope .. $1.00 19 Roman Ballista 50e 20-21 Simple Steam Engine, set 50e 22 "Santa Maria," complete 50c 23-24 Model U. S. S. Ports- I Positively Guarantee MMUSIC LESSONS YOUR HOME mouth set $1.00 to Increase your arms one -bait inch 25 Building a Model Tug- in size, chest one full Inch, strength 25%, health. 100% In one week's 45fil JJ boat 50c time, by following my instructions You can read music like this quickly 26 Twin Cylinder Marine and using my exerciser 10 minutes Write today for our FREEn BOOKLET. It tells how to learn mornings and at night. Send $1 for Engine 50e complete course and exercisers. Sat- to play Piano, Organ, Violin, Mandolin, Guitar, Banjo, etc. refunded. Beginners or advanced layers. Your only expense about 27-31 U. S. S. Truxton $2.00 isfaction guaranteed or $1 3e per day for music and postage used. Biplane 50e PROF. J. A. DRYER AMERICAN SCHOOL of MUSIC.57 Manhattan Bldg.,Chitag0 32 Sopwith Chicago, Ill. 33 Speed Boat 50e Box 1850-L 34 Airplane Engine 50e 35-36 Motor Winch 75c Engine $1.00 SCIENTIFIC MARVEL AIRPLANE 37-38 Vertical Steam 12 -inch scale model of 39 Cannon 50e LIGHTER- WINDPROOF Lindbergh's Spirit of St. What Makes It Light? Louts. Scientifically de- Send Orders to signed and very realistic. All guaranteed. Sample 25 Rises from ground by DEPARTMENT cents. Sample Gold or Silver own power and flies 30 MODEL plated, $1.00. Does the work ft. or more. Easily built SCIENCE AND INVENTION of expensive Lighters. without tools. Construction set , with all parts and full directions, 230 Fifth Avenue Agents Write for Prices In II. S., only 50e. (no stamps). Setts postpaid Send now. York City NEW METHOD MFG. CO. faction or money back. New MANN & BENTON. Box G. Chillicothe. Ohio. Box 5.1.11 Bradford, Pa. i Please say you saw it in SCIENCE and INVENTIO_V

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Compiled by the Staff of RADIO NEWS Completely Revised -Up -to -the-Minute 1001 RADIO QUESTIONS AND structed. Concise, authentic answers A N S W E R S, the most sensational to every question that can possibly be seller in the radio field, is now in its asked concerning the many and varied third new and revised edition. No one branches of radio reception on both interested in radio should be without short-wave and broadcast bands. a copy. The staff of RADIO NEWS, the leading fan magazine, has striven to FANS! Don't hesitate! Get your copy make 1001 RADIO QUESTIONS AND today! Over 112 pages - fully ANSWERS the foremost work of its illustrated- large magazine size IIt kind available. There is a full and complete explanation of every worth- ,0 e while circuit that has appeared since oe c.,04 -.,`'°.-'c.,04-.,`'°.-', the beginning of radio, Sc not only the THE COPY explanation, but also complete dia- ASK YOUR NEWSDEALER grams from which the set can be con- OR WRITE DIRECT I ,s`v4erl, ,,: e- I wro EXPERIMENTER PUBLISHING COMPANY, INC. 44p4 J- 230 Fifth Avenue, New York, N. Y. "t

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www.americanradiohistory.com 647 Science and Invention for November, 1928

PEAK LOAD By E. G. MARTIN (Continued front page 605)

flow of gas and maybe asphyxiating a dozen men before they were cleared; fire might break out and ru riot through the plant. No matter, it was all a part of the day's work. But if the holder "hit the mud," that is, came down to rest upon the bottom of its tank, that was irrepairable disaster. With no gas kft to feed the whirling pumps which dro%e it out into the network of mains and service pipes, service stopped and thousands of phone calls poured into the office. All the effects of months of advertising and promotion work were destroyed in ten minutes. "The elephant never f or- gets"-and neither does the housewife whose dinner has been F.poiled because "the stove won't work." Only once, in Matt Boyle's forty-two years of service, had the Home- stead holder "hit the mud," and that was when floods covered the entire plant, and most of the city, with ten feet of swirling muddy water. Matt found the water -gas house in coln- ACTUAL PRACTICAL EXPERIENCE LESSONS IMPORTANT TO NEWSSTAND READERS order to eliminate all waste and un- INsold copies it has become necessary to And Enjoy New York While Learning supply newsstand dealers only with the actual number of copies for which they have orders. Tais makes it advisable to of giving full information about the place an order with your newsdealer, ask- BOVE is pictured a corner one ing him to reserve a copy for you every of our two seven -story buildings. N. Y. E. S. Course and, showing pic- month. Otherwise he will not be able to for supply your copy. For your convenience, Here, actual work is accomplished and tures of the equipment available we are appending herewith a blank which experience is gained-plus a your personal use in out two seven - we ask you to be good enough to fill in practical and hand to your newsdealer. He Will thorough course in electrical theory, story buildings. IT IS ABSOLUTELY then be in a position to supply copies to FREE TO YOU. you regularly every month. If you are under highly competent instructors interested in reserving your copy every who are themselves, Electrical Experts. month, do not fail to sign this blank. It The New York Electrical School costs you nothing to do so-. Electrical School-this is New York 29 W. 17th St., New York a school noted throughout the world Established 1902 To Newsdealer for its extensively equipped, modern MAUL-TODAY shops, and for the high standard Address each year. Please reserve for me copies of of electrical men released The New York Electrical School SCIENCE AND INVENTION every month who graduate are 29 W. 17th Street, New York until I notify you otherwise, and greatly The thousands oblige, eagerly placed by the big electrical Please send me FREE your 48 -page booklet, puts me under Name companies who recognize the real It is understood that this request no obligation. Address value of men trained by the New York Electrical School. Naine ACTUAL EXPERIENCE plete chaos. The place was full of smoke Address and steam; broken glass and iron fragments PRACTICAL LESSONS covered the floor Men ran about aimlessly, THOROUGH KNOWLEDGE Town.. State..... shouting to each other and prying in the piles of twisted sheet -iron and steel rods. Write today for the 48 -page booklet Over in a corner, someone was screaming and Old Matt made his way there. He found two men trying to give first -aid to Joe Spinelli, the gas -maker's helper. One look SALESMEN ! S100 WEEKLY at Spinelli's blistered face and fore -arms New Model SELL COX HOLDFAST SCREWDRIVERS told him that the helper was through for Men's a while. Strap writtenTwo years guarantee Stokers just off duty were there, faces cov- Watch givejewelednwith thin full ered with coal dust until they looked like IegantS"c2,74,en watch Your choiceio nse PT' --131;C272Z2= masks. The storekeeper was poking among tonneau or cushion shape -same price. Radium did, Also made to use In Yankee or Ratchet Handle. Selle on sight to the debris in search of something, entirely telle time in deck. Accurate Garages, Radio Men, etc. Selt Holding, Selt Releasing. Sample timekeeper and Pa. oblivious of soot falling on his white collar. {testedi ed 8óä ted.nBosh yoour and proposition, 50c. S. J. COX, Dept. J, Franklin, r Yerk. De pt. e5F Men from other departments crowded about postman $3.86 JENKW5,621 roWwar.New 11 the doors, looking on and calling to ask what had happened. 'There were even a couple of women, probably wives of plant -men, who had come after (heir husbands. They looked in with white, sinred faces and shuddered at Wr_TRIAL 13 WEEKS the screams of the injured man until an am- EVERY WEEK Your neighbor. $1 A YEAR. 15 CENTS bulance took him away. know the Pathfinder and yea will like it --the every- Make money taking pictures. Prepare quickly during week news digest from the Nation's Center. Fright. emerged from a cloud of spare time. Also earn while you learn. No experience i tereeting. dependable, different --nothing else like The foreman necessary. New easy method. Nothing else like it. Ìt. Washingtongossip, politics, science,. travel. steam and Matt hailed him. "What is ut, Send at once for free book, Opportunities in Modern fun. Iota of pitures inaroction, entertainment. Photography, and full particulars. -13 Heck?" he shouted. "Where's Fred Ames?" or 611 forfulls year'Send now. Address: L OF PHOTOGRAPHY Pathfinder,orents. Dept. I6, Washington, D. C. "Fred's sick at home," Barry answered Dept. 1d28.3601MicÌtiganAve. Chicago, O.It.A., Please sat i'on saw it in SCIENCE and IN VE,NTION

www.americanradiohistory.com 048 Science, and Inz'!ntion for November, 1928

shortly, "Joe was runnin' the machine, with a Mex. helper. What a mess! Blast -piping blowed to hellangone ; checker -brick down maybe, holder half -full, an' only two hours TVfl!!7j7' (h44 to the peak -load." The foreman hurried away, yelling to the .,////. repair gang. He didn't need to draw a diagram for Old Matt. The peak-load-when the restaurants would begin cooking, gas jets would be lighted in the dark rooms of tenements, and thousands of housewives would hurry home from the movies to start supper-was less than two hours away. There wasn't enough gas in the holder, plus whatever the coal -gas plant could make, to meet the demand. The holder would hit the -in all ils phases! mud and there'd be Hell to pay and no pitch hot. Complete instruction course in three He's Patented Five minutes later, a car slid to a stop in volumes. Every point of aviation effic- front of . the plant and the superintendent iently and thoroughly treated. Subjects Four Inventions hurried in, looking for Barry. Haynes Todd covered in these volumes- ND he's only one of scores of inven- was not a big man but he was a great one- tors who got their first real start through spare -time study with the to himself, at least. His clothes appeared to International Correspondence Schools. have just left the hands of an excellent Jesse G. Vincent, Vice President of the tailor, and he carried his heavy shoulders MODERN Packard Motor Car Company, inventor of and thick neck with all the military pre- AIR CRAFT the Packard Twin Six and co -inventor of cision of a newly -made second lieutenant. the Liberty Motor, is a former I. student. C. S. Todd was a fair -to -average super. He had 700 Pages So is John C. Wahl, inventor of the theories, a few of them having to do with Wahl Adding Machine and the Eversharp gas manufacture, but most of them devoted 500 Illustrations Pencil; W. E. Hallett, inventor of the to sales promotion and civic betterment, any - H. E. Hallett Tandem Gas Engine; Doerr, Contenta of each chapter- Chief Mechanical Engineer, Scullin Steel I. Aircraft Types. II. Company, and W. J. Libby, inventor of Lighter -than -Air Craft. the Libby Mine Hoist Controller. III. Early Airplane De- signs. General Design HERE'S the same coupon-the same opportunity $5,000 for Considerations. IV. De- that these men had. There's still a chance for sign and Construction of you to get ahead if you will only make the start. Aerofoils. V. Arrange- One hour after supper each night, spent with the Perpetual Motion ment, Fabrication and Bracing of Airplane Wings. VI. International Correspondence Schools in the quiet Airplane Fuselage and Landing Gear Construction. of your own home, will prepare you for the position The editors have received thousands of VII. Airplane Power Plant Types and Installation. you want in the work you like best. different designs of perpetual motion de- VIII. Aviation Engine Design and Construction. to prove it. Without vices, have received Air-Cooled Engines. IX. Aviation Engine Design Yes, it will Put it up to us and hundreds of cir- and Construction. Water -Cooled Engines. X. Avia- cost or obligations just mark and mail this coupon. cular letters soliciting finances for the tion Engine Auxiliaries. XI. Aircraft Propeller building of perpetual motion machines. Construction and Action. XII. Airplane Equilib- INTERNATIONAL CORRESPONDENCE SCHOOLS The editors know that if they receive rium and Control Principles. XIII. Uncrating, Set- these letters, there are thousands of others ting Up and Aligning Airplane. XIV. Inspection and "The Universal University" in this country who get similar letters Box 6168-F, Scranton, Penna. Maintenance of Airplanes and Engines. XV. De- and who fall for the claims made in the tails of Modern Airships and Airplanes. XVI. Sea- Without cost or obligation, please send me a copy of numerous prospectuses giving the earning planes, Flying Boats, Amphibians and Other Air- your booklet. "Who Wins particulars capacities of the various machines. craft. XVII. Some Aspects of Commercial Aviation. about e subject before t hicchMIve h ha marked X in tho Most of list below: the shares of stocks for these XVIII. Aircraft Instruments and Aerial Navigation, perpetual motion machines are being sold XIX. Standard Nomenclature for Aeronautics Electrical Engineer Business Management at a rate of $1.00 per share, although some Report No. 240, Part I. an Electrician Advertising inventors Electric Wiring Window Display are trying to sell shares of This book is written in simple, understandable Electric Lighting Show Card and Sign stock at $100.00 per share. language. Telegraph Engineering Lettering Therefore the editors of this publication PRICE Practical Telephony Railroad Positions say, "Just come in and show us-merely $5.00 D Mechanical Engineer D Illustrating SHOW working model of D Mechanical Draftsman Cartooning us-a a per- AVIATION 13 Machine Shop Practice Industrial Management petual motion machine and we will give Toolmaker Secretarial Work you $5,000.00. But the machine must not ENGINES Gas Engineer D Business Correspondence be made to operate by tides, winds, water- Civil Engineer Bookkeeper power, natural evaporation or humidity. This treatise, written by a Surveying and Mapping D Stenographer and Typist It must be recognized authority on all 10 Mining Engineer Accounting and C.P.A. perpetual motion." of the practical aspects of Architect Coaching internal combustion engine Architectural Draftsman Traffic Management construction, maintenance, Architects' Blueprints English and repair. fills the need D Plumbing and Heating Civil Service as no other book does. Sheet Metal Worker Railway Mail Clerk thing that would help along The matter Is logically Navigator D Textile Overseer or Supt. the aggrandize- arranged; all descriptive mat- Chemical Engineer Agriculture D Radio ment of Haynes Todd. He wasn't popular ter Je simply expressed and Pharmacy D Automobiles D French copiously illustrated, so that Salesmanship Poultry Raising Spanish with his more grimy employees, but since he anyone can understand air- spent little time at the plant, wasn't espe- plane engine operation and repair even if without pre- Name cially unpopular either. vious mechanical training. Matt Boyle edged closer as Barry reported This work Is Invaluable for Street Address anyone desiring to become to the super. "Gas leaked into the air -blast an aviator or aviator mechanician. City State piping and blowed up," the foreman ex- 274 PAGES PRICE $1.25 Canadians may send this coupon to International . Corre- plained. "Repair gang say it will take four spondence Schools Canadian, Limited. Montreal, Canada or five hours to get it back in shape. The checker -brick seem to be all right." A. B. C. OF The super frowned importantly. "How AVIATION' long before they'll run?" This book describes the basic "Six hours, maybe eight-can't tell yet." principles of aviation, tells "How about the holder ?" Todd demanded. how a balloon, or dirigible le made, and why it floats In the "Half -full, not near enough," Barry told air. Describes how an airplane him. "I'm files. It shows in detail the. gettin' a fire started in Number different parts of an airplane, Ten." what are, FREE they and what they to Day Trial "Number Ten !" Todd exclaimed. do. Describes all types of air- Too can bare a genuine L. C. Smith (the world's only ball bear- "That planes and how they differ in ing typewriter) for $1 down. Lowest price ever offered! E"/eet pile of junk? Will it run?" construction, as well as determ,. All the 1928 operating attachments. R'-newed. GUAR tailing the advantages and ANTEED FOR 6 YEARS. $1 down and we 'hip. No delay. No "It's got to," Barr_' answered shortly. disadvantages of different tape. 10 day Free Trial. Free Typewriter Cossas. Toot types of aircraft. It includes a Wredaterproof Cover it you act now. Write for it down offer and "It's not so bad, for all it's stood there seven complete area manual. SMITH TYPEWRITER SALES CORP. dictionary of avia- 13h. 360 E. Grand Ave. Chle0S0, IS, or eight years without being used. The tion terms and clear drawings checker -brick are all in place and the of leading airplane. auxiliaries are in fair shape. All she needs PRICE $1.25 is an hour to warm up and a man to run REST GERS her. That's the rub. She's hand -operated, Remit by cash, stamps, check, or money order. you know, and with Ames sick an' Spinelli No C.O.D.'e Men, get Forest Ranger job; $125- in the hospital, I'm the only one left that We Pay $200 month and home furnished; hunt, knows the job. An' I've gotta be in the Postage On All Books fish, trap, etc. For further details, write retort -house making coal -gas." "Oi'll run 'er !" CONSRAD COMPANY, Inc. INST. gtoaur NORTON l* Barry whirled at the voice and saw Matt 230 FIFTH AVENUE NEW YORK Please say y ou saw it in SCIENCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928 649

Boyle shouldering his way closer. Well, why not ? Matt had been a gas -maker once. In fact, he had been the one to start up old Be"NOd7 E `YAY» es 011-Fashioned.Vit7íah Number Ten for the first time, and run her when she was -he newest thing in gas - making machiner. "All right, he said. "Thanks, Matt." They went to look over old Number Ten. She was built in three steel shells standing in a row. The first, ten feet in diameter and twenty feet high, was being filled with white-hot coke, fresh from the coal -gas retorts. This mass of incandescent fuel would be alternately blown to white heat by the NOW mwa *inipler, «miter »ay to Big Pay air -blast and drenched with steam to form the blue, or "water" gas. This gas would be enriched by oil, sprayed upon the heated checker -brick in the other two shells and pass from them :hrough washing and cool- IDI&ITU 1\16 ing processes to the holder. learn' with MOVI FSse, rg *rep a picture! Number Ten didn't look so bad, for all AT last-a quick, complete, fascinating way the paint was peeling from the steel shells to learn Drafting, and learn it right? Experts Professional Instruments and and she was covered with dust. Matt Boyle acknowledge my new, simple, easy "Movie Outfit Method" to be the first new idea in teaching Included-Nothing to Buy climbed heavily up the stairs to the control Drafting in 30 years. It's the most easily grasped, You start out with a complete professional out- platform above the shells. While Barry sound and sensible plan ever devised for Home fit sent to you with your very first Job Sheet. went after for the Study instruction-so clear, so interesting, so Everything is included without extra cost of water old-fashioned practical, that almost before you know it, you're any kind. You learn by using these instruments gauges on the instrument panel, Old Matt through-have finished-and are ready to go and continue to use them on the job when you moved methodically among his levers and to work on a Big Pay Job. get into Drafting Work. valves. He swung open the fueling door and shaded his face with an arm as he peered Learn to Earn-$60 to $100 a Week Investigate- down into That's what the expert draftsman gets. And See These Things First the inferno below. He looked he's never out of work the year 'round- down through a glass -covered peep -hole at for he's the King -Pin of Industry-the Don't sign up for any Drafting Course the checker -brick in the carburetor, noting man they've got to have. Not a wheel until you've investigated my amazing can turn, not a brick can be laid, not a that the brick was already beginning to glow. wire can be strung, until the job has first new "Movie Method." Mail coupon Number Ten had no thermostats ; her op- been planted and drawn on paper by t for Big FREE Book. See my great erator had to judge temperatures by colors. a draftsman. Why don't you get into Earn - While - Learning Plan see work like that? Why don't you be a man - For a minute, Matt Boyle wondered why they can't get along without-a Big Pay the big Professional Drafting Outfit l you get no he had Man with a year 'round Big Pay Job? ' at extra cost-learn about volunteered for this job. He cer- You tainly didn't owe the Homestead anything, can-it's easy-I'll show you how. my Nation - wide Job Service - my and this wasn't going to be any picnic. Why I'll Quickly Prepare You for positive Money Back Agreement. Mai I not let the super burn his own fingers? a Big coupon NOW t he Pay Drafting Job Then looked at the holder and forgot With my new everything else. It was dropping-fast. copyrighted K. M. BOYD, "Movie Method," I'll help Director. The hot -valves you get ready for a Big Pay were rusted fast, but Matt Draftsman's job so quickly you found a short section of pipe and hammered will be astonished. Spare time \ MAIL COUPON FOR FREE 13001 them loose. Then he drenched them in oil only needed. With my meth- until they moved freely. He inserted the od-just like "slow motion . K. M. BOYD, Director movirs"-you see how it's bBigPayW I! Practical Drafting Institute of America. oil nozzle and made the connections that al- done in pictures and you do it Draftingi Dept. 28, 2154 Lawrence Ave.. Chicago, Ill. yourself almost automatically. lowed water to circulate through it and keep 1,1,w .,<,,Moe., Send me your book, "Draw Big Pay in Draf4- It's amazingly simple-yet so MS." and tell me more about your "Movie it from burning up. He climbed a short thorough and complete, you Method." This does not obligate me in any way ladder to light the pilot flame at the stack learn Drafting from A to Z- Name and poured oil on the bearings of learn it sa you can sit in with . the heavy the best of stack -valve. Last of all, he wound the clock. them on the Jobs Address that pay Big Money. State The clock was important, for water -gas -./ City. making is not a continuous process ; it is done in cycles. Four minutes of air -blast The WAY-is the BIG PAY WAY heat the fuel to incandescence; steam and oil t are sprayed in for six minutes of "make"; then the blast is started and air and gas together are forced through the machine for Make Your Radio one minute of "purging." Then, do it all over again. Clear as At 4:30, Number Ten went "on the line." nS a Bell Steam and smoke gushed from loose joints Últt%1 EL and dried -out valve boxes; oil pressure 'F MARV ea GROUND AERIAL. dropped continually as the wheezy pumps I;r tried to keep up ; but the relief holder, into ls Get Amazing Distance, Greater Volume which the gas was first blown, began to In yyLaterboraattomany your rise. Sub -Aerial Is theI d best for and Selectivity Clarity of tone and elimina- Without Distortion "Star-rt yer pumps !" Old Matt bellowed; tion of static, also for greater Why go on listening to terrible static and other maddening outside noises? volume and selectivity. It Now you can get the real music your present Radio is capable of giving, and the exhausters which moved the gas will fill a long -felt want among the Radio Fans." by hooking your set onto the clear, practically static -free ground waves from the relief tank to the main supply lines A. B. Johnson, with Sub -Aerial The air is always full of static and your overhead aerial began to throb. It was time, Radio Engineer. picks it up and brings it to your speaker. So why stay In the air-when too! The big you can ¡use the whole earth holder was lower than he had ever seen it as a static and noise filter with Sub -Aerial? at this time of day ; and the peak load had Low Original Cost-No Upkeep Cost barely started. Matt turned to his levers and Sub -Aerial costs no more than an overhead or loop aerial and less than many his clock. Its first cost is the only one. SUB -AERIAL Is permanent. No trouble-no / hard work, or risking your neck on roofs. / Underground The superintendent was walking nervously Aerial Systems SUB -AERIAL Is guaranteedagalnor / Dept. back and forth across the iron floor -plates, 25 -YEAR GUARANTEE any detects In workmanship or / 863-P, S., material andtagalnst deterioration for 25 years. Any SUB-AERIAL or. Clair Bldg., looking out has been installed according which Cor. St. Clair & of the window at the holder to directions and proves defective or deteriorates / Erie Sts., Chicago, within 25 years, will be replaced free of charge; and also we will pay 31.00 111. and getting in Matt's way until the white- forinstalling any such new replacement. / haired old Irishman growled at him to keep / Send me complete In We know so well the surprising results pr000f, and out from under loot. Then he went down- TRY IT FREE' you'll get that we'll let you put In a / FeTTriai Offr, stairs to give orders and Sub -Aerial entirely at our Risk. You be the Judge. Don't take / No obligation. interfere with the down your overhead Aerial. Pick a summer night when static work of the repair gang. and noise interference on your old Aerial are "Just Terrible." If Sub-Aerial doesn't Sell Itselfto You Right Then on Per / Barry had gone over to the coal -gas plant. foDope needn't Name Matt Boyle could see the stokers, their on Suob-Aeril. You'llbe surprised n Doo it NÓthee Can Be Installed in a Few clothes smoking from the heat, pulling half- Minutes / as baked coke from the retorts to make room UNDERGROUND AERIAL SYSTEMS -; for new charges of coal. Others were throw- St. Clair Bldg.. Dept. 863-P. S. ing "guns," six-foot lengths of pipe filled Cor. St. Clair and Erie Sts.. CHICAGO. ILL. / City State Please say you satt it in SCIENCE and INVENTION

www.americanradiohistory.com 650 Science and Invention for November, 1928

with oil and stoppered with rags, into the retorts on top of the coal. This would make the gas richer and increase the amount made a little, not much. From the other end of the building, a faint beating of hammers, barely audible above the din of old Number Ten's clattering auxiliaries, told Matt the repair gang were getting new blast -pipes into place. The auto- DIESEL & OIL matic machines would be ready for action in a few hours, but that wouldn't do any good for tonight's peak -load. That was up to Old Matt, the man who was too old to ENGINEERING work for the Homestead any longer, and to Number Ten, the "junk -pile," that had been Bigger left standing because it wasn't especially in A Job the way. After the next period of re -fueling, Matt HAND BOOK

and You're the Man took time " to glance over at the holder. Are you hunting a bigger job, or does the bigger Jerusalem, my happy home! It was low! (Rosbloom) job hunt you? Why waste priceless years at routine They were fairly on the peak now, it was work, when you can acquire at home in a comparatively few months the specialized knowledge for 5:30, and half an hour to go before the which bigfirms pay big money? Thousands of men maximum was reached and the demand be- bave greatly increased - their incomes by home - C+2G gan to drop off ; an hour or more before they study business training under the LaSalle Problem ;?5 wYkss, Method. Let us show you how you can do just as would be safe. Number Ten groaned and well or better. The coupon will bring you complete erupted smoke and steam from every crevice. S LE,E Information, together with details of our convenient payment pian; also your free copy of a remarkable Those leaks worried Matt, not because of book-"Ten Years' Promotion in One." Make your the smoke and steam but because of what 11.4.1:,11-';;`¡o toward that bigger job tòday, " start went with them. One of the main con- *ó0GitWDBÖNIrÍL -Find Yourself Through LaSalle!- - stituents of water -gas is the deadly carbon yti:a-.ZN:ií.: I LaSalle Extension monoxide, which steals up on a man and University kills him before he even suspects its pres- :+.;. Dept.11384-R Chicago Please send me full information regarding the course and service I have marked 9 i with an X below. Aleo a copy of "Ten Years' Promo- tion in_ One." all without EXPOSÉS of obligation to me. e +^ci:s:u.tu Business Management: Training for Official, Man- %:A.tILI'''. ,:SZ agerial, Sales and Departmental Executive positions. SCIENTIFIC Modern Salesmanship: Training for position as Sales Executive, Salesman, Sales Coach or Trainer, Sales Promotion Manager, Manufacturera' Agent, Fourth Enlarged Edition Solicitor, and all positions in retail, wholesale or SWINDLES specialty selling. D Higher Accountancy: Training for position ac Audi- tor, Comptroller, Certified Public Accountant, Cost appear often in The World's Accountant, etc. Standard Traffic Management: Training for position as Rail- road or Industrial Traffic Manager, Rate Expert, Book on Diesel and Freight Solicitor, etc. Science and Invention Law: IL. B. Degree. Other Classes of Oil Banking and Finance: Training for executive posi- If you know of some hocus-pocus tions in Banks and Financial institutions. Engines ModernForemanship:Training for positions in Shop scheme Management, such as that of Superintendent, Gen- being used to swindle the eral Foreman, Foreman, Sub -Foreman, etc. public-write the Editor about it. Industrial Management: Training foryositisns in Works Management, Production Control, Industrial A remarkable book of great- Engineering, etc. Management: Training in the position of est value to all engineers, PersonnelPersonnel Manager, industrial Relations Managger, Employment Manager, and positions relating to Em- mechanics, and ployee Service. others in- Modern Business Correspondence: Training for ence. The back of Matt's head was begin- D Sales or Collection Correspondent, Sales Promotion ning to throb and the old-timer realized.that terested in Diesel engines Manager, Mail Sales Manager, Secretary, etc. Stenography: Training in the new superior short- his blood was filling up with something that for land, marine, locomotive, hand, Stenotypy. wasn't going to do him any good. He or- Railway Station Effective Speaking. dered the helper to stay by the open window automobile, and aircraft use. Management. - C. P. A. Coaching. and went there himself as often as he could. Over 300 tables, hundreds of Expert Bookkeeping. Commercial Spanish. Something went wrong,down in the yard. Business English. Stenotypy. Men were running with buckets and shout- formulae, profusely illus- i Commercial Law. D Telegraphy. ing. Matt couldn't hear what they were trated with color and plain I Credit and Collection Correspondence. saying for the noise all around him, but he views. Courses of instruc- supposed they were calling for the foreman. I Name Just like a bunch of Bohunks and Mexicans, tion on all leading types. IPresent Position he thought ; run around and fall over themselves, and yell for somebody to come tell 830 pages. Size 5 x 7 inches. Address 'em what to do. He noticed that his relief Bound in flexible, semi -flex- holder was getting low. "Speed up thim pumps !" he roared to the ible and stiff covers of very man below. The fellow yelled something attractive imitation leather The Musical Sensation back at him, but Matt couldn't hear. Then Barry arrived and two men went climbing with reinforced back. ACCORDEON up on the huge cylindrical tanks that were Music Rolls the purifiers. Playedby Price $5x00 Prepaid Without any knowledge of Music or Notes you play in a few "Box clogged," the foreman called up as he minutes, perfect like an Artist, latest hits, songs and dances. passed under Matt's window on his way back No study or practice. Nobody can see the arrangement. Three models: $40.00, $55.00. $70.00. Every Instrument guaran- to the coal -gas plant. "By-passed 'er." teed. Interesting Circular No. 3 and Roll List mailed free. gas lost, reflected, Order Direct from Book TREASURE SALES COMPANY More Matt and the 1690 Boston Road - - New York, N. Y. purifier out of action. The gas would smell some, but that was better than losing the Department holder. He looked out again. The big tank was going down like an elevator. Pumps EXPERIMENTER L99Äútómátic were dragging gas out: of his relief holder as PUB. CO. WITH You need no license or No Permit loo mutt°.úeef2:Required fast as he could put it in, but it didn't seem 230 Fifth Avenue, New York CART- fun or self-defence.keeps away tramps, to make any' difference. RIDGES Frightens thieves. scares away dogs- Fe I home proteetor. Fool your friends. ae expensive automatic in conetruc- He saw the foreman. run out of a door eSemenoo,llniehn p earanca,durabilit :a somatic and go up the ladder, on the holder like a nmeazine I adina and ejection tridges, Instantly and powerful report. Guaranteedabsolutary monkey. Plainly, safe. Send no money. Pay expressman $4.99 for automatic with 100 scorched Barry was doing carte dgee. JENKINS, 621 Broadway, New York, Dept 65 J11 some worrying. Well, he had something to e.s% Please say you saw it in SCIENCE and INNEN TION

www.americanradiohistory.com Science and Invention for November, 1928 651

worry about. The chances of stopping that downward rush w'.re those of the proverbial celluloid cat. Todd was out in the yard, yelling up at the foreman and Barry was yelling back at the super. Matt couldn't hear what was said, but he could guess. Matt wearily nulled back the throttle lever and the shrill scream of the blower died to a gentle hum. He swung his weight on another lever and the two hundred -pound stack -valve closed down. he Then twisted t8"COM POO \ND the handle of the steam valve and looked up TOOL at his oil gauge with eyes that refused to focus properly. The oil pressure was low, of course; he wouldn't get near enough in, this run-but it couldn't be helped. Todd had disappeared. Probably the super had gone to warn the phone company. When that holder hit the mud, the telephone busi- TILTING ness was TOP TABLE due to pide up. No use to put calls SIZE through to the Homestead office. Let the 13`x hello -girls tell the sad story. Matt couldn't help a tingle of satisfaction. There'd be others worrying about their jobs -and they wouldn't be sixty years old, IN CHARACTER either. It would be tough on Barry, though. ACE 'Hen Jólri OJtlJDirettfromFníaur:f That stiff-necked 3 year. testing i Todd would pass the buck of experimenting and improvement ie wrapped up to each new Red Jacket Boma Work Shop. The finest tools and aeressories to the foreman. Or, if it missed him, it'd that can be made go with eachoeeemiy order. Red Jacket equipment is Make It designed. tested. approved and guaranteed by Wm. L. A -Iw: rd light on Spinelli. The little Wop had a wife tin lly known er,ttemen and manufacturer. whow hue developed bio Yourself/ hobby into a co-operative a,eociation of thousands of craftsmen. ti and about seventeen kids-and him in hos- F.,tbnn, Frntrr pital done up in picric acid bandages. Portable--Interchangeable-- it th Wnctr-. Ali Aluminum Me.,or Dnll httuo. Another clamor of voices caught I`ed:.x Matt's Complete RED JACKET lilting Not Table 11,115 in. attention and he looked Patented Compound load down the elevator f'fn..t Luolk. H.,n,l l,od. HOME WORK SHOP unnmditwvul wall. He groaned. That did finish it! The The new Red Ja ket Combination of Electric tools brings you a Red Cu.mnrn Jacket Rand caw and in addition the powerful Red Jacket Master Drill L'nl' 'rd srni.e rickety old elevator, which had to carry a Motor with direct drive to the Waco C f,¡teman'g wood turning lathe geed (he Code of Rm.nr.t tth .:. -- sloe pound and 18 este, a tilting top mitre saw 7000 Huppv stream of fresh fuel to Number Ten (ca city O'o ban laide¢ scroll and ;ig euw,nnd nlfne,.raeorh., 14, Wu,'" Ott moa. was with[{os,bsth for portable and stationary power drilling. butting. grincing and clruning. Arr dreg to stuck. He caught sight of Haynes Todd light socket and converts your work Limit into a complete private It i, n complete chest full tool end meriting shop. of cleat r,aa lly driven tool, cesigned for the private une of and, beyond him, of Barry coming with a tr of lovers and men who create. repair end approeluto buddy tool, at horne. crow -bar. Make Things at Home "Don't pry ut !" Matt yelled. That a Rend coupon et once for information Electrically was valuable to those interested in benne-Gt I handiwork, It is FREE. It telle you how easy it is to operate a Red Jacket set of tools rid liste the advantages and privileges that are temperamental elevator, always had been. free to member craftsmen. Don't miss knowing all about W nro. You are invited. Look outretailer.at Waco-you wianot find WACO TOOLS by An old-style hydrau_ic, pushed up on a piston A:l solen made dir000nefroRed factory, ono gold from below, it had at habit of tilting sidewise Special Crafts Course FREE in its guides and jamming. Matt remem- SPECIAL CRAFTS COURSE and blueprint service is free toned Jorkrt chop owners-all there is to know about handicraft methods, raw ateals. woods, carving, sawing, turning, designing, carpentering. decorating. is taught by bered a time they'd tried to pry it loose and ,pecitlncorrespondence. - had to tear out all four guides it Buy On Your to get clear. gí0.00 Own Terms Only down. Lihernl discount for cook. Easy monthly r:V'ment plane. It in no hard - Loring Cnp What it needed now was a big screw -jack to 45° Tilt a Red Jnrket. Woo By Wacn set under it Top Grand P-ise of and give it a "hist." No time Table SendSendown the An,ericnr Mae - ter Cratt,men's for that either, not low. free COUPON WACO TOOL WORKS. Inc. .aoeiatitn. The FAMOUS - i "Oh, Barry! Tale 'er fer this run," he WACO BLU E Sub W. Kinzie St. Chicagot o hf m Drpt. "I 1. 19e a e ,d , inn tree information .,nd literature on called. "Blast on, at 5:48." GUARANTEE PRINTS Literature Free J Red Jacket Awcto bile. and k'ItEE Ser' ,... If it is not what .Send the coupon. You will I you want when you Barry heard him, and ran up the ladder as Name get it send it titi 1t, :Ifni. sln,t r,tvvtive,thP,oeineiin¢ , Matt Boyle climbed down the guide to the back. - luter ueeting. Fia in and MAIL TODAY. platform. It was caught midway between IAddress floors and there was a steel buggy containing five hundred ponlnds of coke to be got rid of. Pushing it off would finish that buggy, but there was an extra one outside and Matt couldn't wait to build a runway. His fire was low now, and would have to or TAKING have more fuel in the next ten minutes if Number Ten was to keep running. "Git out the way!" Bohunks scattered in all directions and PICTURES Matt gave the coke -buggy a shove that dropped it on the floor, well out of the way. He climbed down and peered under the platform. As he expected, one corner was tilted down. "T'ree av yez lift on thot edge," he called, What Others Are Doing Working "It is possible for me to earn more in his spare time, J. TI. Wade made $200 in 2 weeks. He and crawled into the pit himself. money now than I ever dill." Alfred writes: 'I find work only waiting for someone capable of doing "Come out of that !" Haynes Jacques. it, and the possibilities are beyond my fondest hopes." Todd had 'It gives me great pleasure to All over the world men and women are earning splendid incomes completed his telephoning and was back on thank you for pla'itfg amt. I expect in the fascinating profession of Photography. There are big to make great headway." C. A. opportunities everywhere for snare hours or full the job, giving fool crders as usual. "Don't I time. Find out larrison. how you can quickly qualify you know that platform will mash you flat "1 have made a connection as to make real money in Motion Picture t 'ameraman with the Universal Photography; Portraiture, Commercial and News Photography. if it falls?" Pictures Corporation. 2375.110 a Turn your spare hours into profit; or step into a good -paying wcck isn't so had for a starter, is position; or open your own studio. The field is unlimited. Boyle paid no at:ention to the excited it P" W. B. Holcombe. super. He was hunting for footholds, and PROFESSIONAL CAMERA GIVEN

! You can start making money almost immediately. Your choice of Motion found them-praise be He got a shoulder Be a Movie I 'icture or View Camera. See how easily you can get started inthis fascinating work. against the platform and heaved. Nothing NO PREVIOUS EXPERIENCE NEEDED Operator happened. Our staff of famous experts will teach you everything. And you can learn in Motion Picture your own home or in our great New York studios. Operating and Pro- He strained again, and the laborers out- jection taught at FREE BOOK. Send for handsome, illustrated hook explaining the many home. Get a good side lifted with him. That platform might opportunities in Professional Photography and how you can take advantage of pay Job with Movie have been them. Job chart and details of Free Employment or Vaudeville Thea- built solid with the guides, for Service included. Write today. tre. Projector given all the move it made. N. Y. INSTITUTE OF PHOTOGRAPHY, with course. Write Dept. 82 for Folder. "Howly Pathrick help me !" Matt whis- 10 WEST 33rd ST., NEW YORK, N. Y. pered between clenched jaws. Whether the good Saint lent a hand or the thews and sinews of Buck Boyle that Insure was, lived again for that minute in Olc! your copy reaching you each month. Subscribe to Science and Invention -12.50 g year. Experimenter Publishing Co., 230 Fifth Matt's trembling body, doesn't matter. The Avenue, N. Y. C. Please say you sait' if in .SCIENCE_ and INVENTION

www.americanradiohistory.com 652 Science and Invention for November, 1928

platform moved! ft rose an inch, quivered WE WILL TRAIN YOU -slid easily upward. IN A FEW MONTHS "Fill thot other buggy," Matt shouted to his helper, and hurried back to relieve Barry. Day and His first glance was for the holder. It was Then Night still visible above the rim of the tank. Read --- he looked at the dock -6:10. Schools in "Praise the Saints !" he said. Chicago, Barry grinned. "Yeah, she's safe. All we gotta do is hold her." Detroit, At eight o'clock, the coal -gas plant caught RADIO Cleve- up with the demand and they shut down land, Number Ten. It was time, for a blower NEWS Boston, bearing was white-hot and she was leaking Phila. more gas than she was sending into the relief holder. Experts Earn Matt Boyle, with a raging headache but THESE otherwise pretty chipper for a man past Up To sixty, was sitting on a work -bench watching SPECIAL SECTIONS the repair gang test the new blast -piping. FOR EVERY FAN $125 A WEEK The holder was safe now, going up like a as Mechanical sky -rocket, Barry said. Besides the latest set construction articles The super found him there. Matt Boyle and editorial matter covering each new Dentists development. there are many sections that and old Number Ten had just saved Mr. make RADIO NEWS especially attractive We teach you to Todd from a disgrace which would have to all radio enthusiasts. make rubber plates, followed him as long as he stayed in the gas crowns, bridge work, business. And the super knew it. More- THE LISTENER SPEAKS metal base dentures, over, there had been given to Haynes Todd This section belongs to the readers of RADIO etc., NEWS. Its purpose is to provide a common for dentists. in those moments of stress to glimpse some- "stamping ground" for the views of the radio After graduating you thing of the blind fealty to an idea that ani- public Here the readers discuss among them- are ready for a job or mated such men as Matt Boyle. He was a selves all questions of interest to radio. canopenyourown lab- little awed, a little ashamed, so that he spoke oratory. We assist you. BROADCASTATICS almost diffidently. A page devoted to humor of purely radio interest. BIG DEMAND FOR MEN! All contributions published are paid for at the "All right now, Matt ?" he asked. "You rate of $1.00. There is many a hearty laugh in Mechanical Dentistry is the laboratory bench work how I feel about what you've just which the dentist turns over to the laboratory know each issue. worker. Master this profession and help meet the done-on top of everything else. I'm going demand of 64,000 dentists for laboratory work. Every to take up your case tvith the directors to- TELEVISION city and every town where dentists are located offers A which morrow ; an exception to their retirement section in the latest developments of work to the mechanical dentist. We train you in a television are reviewed each month. This com- few months in day or night school for this uncrowded rule won't hurt them. You're too good a paratively new industry is fast gaining popu- field-no classes-no books-no mechanical ex- man to Iose." larity. It opens a new field for experimenting perience necessary. our friend, the "fan," Old Matt shook his head. Strangely to WORK YOUR WAY THRU SCHOOL enough, all bitterness toward the super had WHAT'S NEW IN RADIO \Ve will help you find a job to meet your expenses vanished. After all, Todd was doing the Wherein all new radio apparatus is fully while taking our training. And we will help you best he could for the company, just as they described and its use explained. This section find satisfactory living quarters when you arrive. is especially valuable to set builders. Schools located in Chicago, Detroit, Cleveland, all were. But Matt felt old, tired of black Boston, Philadelphia. Day and night schools. smoke and the odor of tar and ammonia. It THE RADIO BEGINNER would be nice to have green things growing As its name signifies, this section is devoted INTERESTING FREE BOOK -covered porch Dentistry around him-to sit on a vine to the radio beginner. All the elementary Our illustrated, free book on Mechanical and smoke his old clay. principles of radio are discussed and full con- will acquaint you with some surprisingly interesting structional data for the simpler sets given. facts. It tells about the thriving profession of Full-sized blue prints of the circuits treated Mechanical Dentistry-the way to swift and certain "Don't do ut, Mister Todd," he said slowly. are FREE. success. And it tells about the progress of many of "Oi'm plannin' t' buy me a bit av ground an' our graduates-men who have succeeded beyond toime Oi their expectations, also full details of our liberal raise -me a flock o' bur-ruds. Ut's RADIO WRINKLES offers. Mail the coupon and find out more about was restin' a bit." He grinned suddenly, This department contains many suggestions this fascinating opportunity. understandingly, at the super. "Ut's your helpful to the radio enthusiasts. Each con- Tune in WBBM (389.4 meters) for McCarrie hour job now, Sorr, t' kape her outa the mud." tribution published entitles the author to a at 7.30 P.M. Central Standard Time year's subscription to RADIO NEWS or, in each Monday cases where he is already a subscriber, a year's McCarrie School of Mechanical Dentistry subscription to either SCIENCE AND INVEN- TION or AMAZING STORIES. 1338 S. Michigan Ave., Dept. 183, Chicago, 111. r RADIOTICS McCARRIE SCHOOL OF MECHANICAL DENTISTRY $31,000.00 FOR SPIRITS Ill. A humorous page of misprints contributed by 1338 S. Michigan Ave., Dept. 183, Chicago, our readers. For each one published $1.00 will Without cost or obligation, send me your illustrated book $1,000.00 was offered by this publi- be paid, provided that the actual article in which on Mechanical Dentistry, and complete information as to the misprint occurs is enclosed with a few my opportunities in dental laboratory work. cation in the June, 1923, issue for humorous words from the reader. spirit manifestations that could not be Name RADIO NEWS LABORATORIES duplicated or explained by scientific In this section all apparatus awarded the RA- Address means. DIO NEWS !LABORATORY CERTIFICATE OF J MERIT in the month past is listed, and a technical description given of its purpose and $10,000.00 for spiritual phenomena characteristics. was offered through SCIENCE AND IN- WANT TO KNOW VENTION by Joseph F. Rinn in the Au- I This department is conducted by Mr. C. W. gust, 1923, issue. Palmer. Its purpose is to answer the difficulties A Brand New of our readers. The value in which the "fans" High Crade Fine Tone $10,000.00 was offered through Sct- hold this section can be better realized when VIOLIN, TENOR BANJO, HAWAIIAN GUITAR one considers that there are over 5,000 letters BANJO, CORNET, UKULELE. BANJO UKULELE, ENCE AND INVENTION Magazine by Jo- GITAWe R extraMAN received from readers each month. Naturally will give ou without charge when you enroll, any Instru- only the more important ones are printed in t you select and teach you to play it by our NEW copyrighted seph Dunninger for spiritual manifes- easy to learn home -study course. Over 600,000 men, bo a RADIO NEWS. d girls have learned to play by our simplified method. Coat laeonu', tations which he could not explain or pay Do not neglect to obtain your copy of learn.eInstrument andfirst lesson. Benton FREE trial. ltoday. RADIO NEWS. Each issue over 100 pages. CH11632CORRESPONDENCEC SCHOOL Ocago' duplicate by scientific means under ¡misted St., Dept. Chi ill. Fully illustrated-large magazine size. oitd identical conditions. LEARN CARTOONING $10,000.00 is now offered through At Homo-In Your Span Time THE COPY The famous Picture Chart Method this publication by Mrs. Houdini for 25c of teaching original drawing has opened the door of success for hun- the ten -word message which Houdini dreds of beginners. Whether you think you have talent or not, send promised to deliver. AT ALL NEWSSTANDS OR WRITE DIRECT for sample chart to test your ability, and examples of the work of TOTAL: $31,000.00 for spirit mani- EXPERIMENTER PUBLISHING students earning from $50 to $300 CO., INC. per week. Please state your age. festations. 230 FIFTH AVENUE - - NEW YORK, N. Y. THE LAN DONSCHOOL 1460 National Bldg., Cleveland, O. I'lease say 3 0 it Sa îC it in SCIE.VCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928 633

READERS FORUM (Continued front page 617) il

Then slowly as rt came into its orbit and ap- proached the sun, the ice upon its surface melted, leaving it covered with water. In this water generation was going on, every atom and substance in the water came together, and the combination made a germ; the germs made something else and so on until the water was infested with beings of all kinds. Some of the beings lived upon their own species by killing them, and so these beings learned to protect. themselves As time passd they became more intelligent, some of them developing great intelligence. I do not believe man derived from the monkeys, but I do believe he derived from these intelligent beings who fought for their place on the earth's crust. From the preceding theory we derived from the water atoms tad molecules. Must Water is our life -preserving food. When it Men Suffer after4O? is gone then we shall perish because the clouds will be no more and the sun's heat will beat Awell-known scientist's new book about old down upon the surface as it does upon the deserts age reveals facts which to many men will be Send for FREE Book today. amazing. Did you know that two-thirds of all If you have gland trouble, or any of the symp- men past middle age are said to have a certain I should like to be the last man on earth, gasp- toms mentioned, write today for scientist's free seldom mentioned disorder? Do you know the hook, "Why Many Men Are Old I would not be far at Forty." You ing for breath; believe I frequent cause of this decline in vitality? can ask yourself certain frank questions that may wrong in what I have written. reveal your true condition. Every man past 90 If this earth was to have been created before Common "Old Age" Symptoms should make this test, as insidious prostate disorder the universe, how is it that astronomers claim Medical men know this condition as hypertrophy often leads to surgery. This book is that there are bodies in the universe that are of the prostate gland. absolutely free, but mail coupon immediately, as Science now reveals that the is much more aged than the world. Perhaps the this swollen gland-painless in itself-not only edition limited. Address astronomers are wrong. I do not think so. often cheats men of vitality, but also bears on THE ELECTRO THERMAL CO. Generation is generation the world over, and the bladder and is often directly responsible for sciatica, backache, pains in the legs 4511 Morris Ave. Steubenville, Ohio where there is not a male or female substance, and feet and dizziness. When allowed to run on it is fre- If you live West of the Rockies, mail your inquiry to there is a positive and a negative. These brought quently the cause of cystitis, severe bladder The ElectroThermal together-something is the result. This world is it. inflammation. 303 Van Nuys Building, Dept. 45-L A. R. CAN N, Victoria, B. C., Canada. 65% Are Said to Have This LOS ANGELES. CALIF. (We do not believe it possible that this earth Gland Disorder The Electro Thermal Company, was at one time a part of the crust that was on Prostate trouble is now reached immediately by 4511 Morris Ave., Steubenville, Ohio fact is no proof a new kind of safe home hygiene that goes the sun. As a matter of there directly Please send me Free, and without obliga- or indication that the sun ever bad a crust. to the gland itself, without drugs, medicine. massage, or application of electricity. Abso- tion, a copy of your booklet, "Why Many The sun was probably in a nebulous state at lutely safe. 40,000 men have used it to restore Men Are Old at 40." Mail in plain wrapper. one time and gradually became more and more the prostate gland to normal functioning. The constricted. This earth also may have been a principle involved is recommended by many Name sun millions and millions of years ago. In physicians. Amazing recoveries often made in traveling through the universe it was probably six days. Another grateful effect is usually the Address immediate disappearance of chronic constipation. captured by the sun and in the course of this Usually the entire body is toned up. City State. or Either you capture, either the moon was thrown off the fee! ten years younger in six days or the treat- Canadian :Address: 44 Yonge St., Toronto, moon was previously captured by the earth. ment east, nothing. Can. There is no indication that germs are made from atoms and substances in water coming together. Spontaneous development of life is TRAVEL ON "UNCLE SAM'S" PAYROLL one of the theorier; still adhered to by scientists. Railway Postal Clerks Others believe that life on this planet came $158 to $225 a Month from another planet in the universe. There is Mail Coupon Before You Lose It a fair indication cf proof that organisms entirely on ------all unknown to us have been discovered in meteoric FRANKLIN INSTITUTE, Dept. J 177, bodies and that these organisms have been Rochester, N. Y. actually developed. Ctrs: Rush to me without charge-copy of 32 -page book, There is also a fair indication this earth "How to Get U. S. Government Jobs," with sample coach- that list of positions obtainable and full particulars telling was never all water. While water did recede 'Mg,hot to get them. here and there, land also piled up in other places. Some parts of this earth had glacial STEADY WORK-NO LAYOFFS-PAID VACATIONS ,Name Common Education Usually Sufficient" drifts, others had none. Many It is also the consensus of opinion that while Other Govenfinent'Jobe Obtainable b Address man did not come from a monkey he was derived from a stock of which the monkey is also NOW! You Can Do Your a descendent. Own NICKEL -PLATING Inasmuch as nobody knows how much water For Plating Nickel, MAKE $150 TO $500 A WEEK there was on this earth a thousand years ago, Brass, Copper, New Scientific Invention Enables Anyone to Nickel -Plate is impossible to predict lee . Anywhere with Aladdin Portable Outfit it that a time will come, fjs Silver, is when, eventually be no NICKEL -PLATE there will living beings MA./ 13: C o l d , anywth ere; einuthe Home, Genablesaragee, Ofce,e Store In you canh upon the earth. In the course of these evolu- F/ do all the NICKEL -PLATING on any automobile, bathroom fixtures, etc. the tionary changes it is possible that man will also iik, ELECTRO so evolute that he can do with practically no $650 very short THE NICKEL FLOW EWOtUTFIT water. 6 movingSEEmoving any of the parts. This Interests every auto owner (and others) because F. O. B. you can NOW take the Plater to the job Instead of taking the job to the Plater. No astrologist ever stated that this earth was RACINE This offers wonderful ECONOMY to users and BIG MONEY -MAKING created before the universe, such a thing is Plus possibilities to AGENTS. Be the first in your locality. impossible, because Postage Write for Free Booklet-Agents Wanted Everywhere this earth forms a part P. J. F. BATENBURG Dept. 39 RACINE, WISCONSIN of the universe. There is no theory for the creation of the universe, its size or its age. These things are even beyond the scope of the imagination. You stated that "A generation is a generation COMPLETES YOUR MACHINE SHOP- ¢` the world over, and where it is not a male or EVRY-USE Electric MOTOR ATTACHMENT a female, it is a negative or a positive." Here on no ul- your is eystor belts necessary.s Holds grr indstones, statement incorrect. In the amoeba, in tit buffs, saws, wire scratch brushes, drills, etc. the paramecium, in the diatom, and other one - as pulley. Made to fit %e, 3s and plant or inch shafts. State size. Postage prepaid if celled animal life there is no positive remittance accompanies order. or negative; no male and female. When the ',UNITED ELECTRIC MOTOR animal gets larger, its body merely splits in two 178F1 1 Centre Street. New York, N. Y. and the result is that we have a new generation. Both the parent and the portion thereof that was MEN TO LEARN split off become revived by this process, and . Print Your Own MOTION Cards, Stationery, Circulars, Paper, etc. Save PICTURE PROJECTION life goes on as with two newly born. No posi- money. Print for others, big profit. Complete A BIG -MONEY PROFESSION-$2,000 TO $4.000 We tive or negative-just a simple mystery-EDI- c\¶tt ' outfits 88.85. Job press Ell, $29, Rotary $149. All Assist Stu s to Earn While Learning easy, rules sent. Write for catalog presses type TOR.) Ekcrls,ufl MOVIE OPERATORSORS SCHOOL 1_ etc. THE KELSEY CO., P.O. Meriden. Conn. 51 Sproat Street Detroit, Michigan Pl rasr .c"r r nat sa7o it in SCIEVCF. and INT7F `.'T/nN

www.americanradiohistory.com Science and Invention for Novenfber, 1928

ELECTRICAL TRADE SHOW Electrical contractors, wholesalers, retail- ers and buyers of electrical goods, and all SAVE YOUR MONEY ! others engaged in the business of distributing, and supplying electrical appliances through- BE YOUR OWN SERVICE MAN out the United States, will have their own trade show in New York City in October, THE RADIO where assembled in one place they may see TROUBLE exhibited and demonstrated the thousands THE RADII FINDER of approved electrical devices used in the TROUBLE FINDER to face the %alsl Ste,a Even the highest - modern home and meet face priced radio set manufacturers or their representatives. occasionally de- This will be the first electrical trade show nation- velops a fault and ever held anywhere, and it will be that at a time wide in scope: It will be held on October when you least 17, 18 and 19 in the Grand Central Palace. expect it-maybe Arthur Williams, vice-president in charge right in the mid- of commercial relations of The New York dle of an interest- Edison Company and president of the Elec- ing program. But, trical and Industrial Exposition, who made a handy copy of the announcement of the trade show, ex- The Radio Trouble Finder is the sim- plained that the trade show is an expansion ple means for tracing every defect and on a national basis of the annual electrical remedying it in the easiest manner `Another show, with the first three days set apart ex- possible. There is no mishap that could clusively for the trade, and the final seven befall a radio, but what is fully covered days open to the general or consuming pub- in this valuable book. to expand the annual elec- $ 10 Raise!" lic. The" decision The Radio Trouble Finder is edited a trade show on a national 'Why, that's the third increase I've had trical show into by men fully versed in the subject basis was made in response to recommenda- with years of actual ex- in a year! It shows what special training from important fac- covered-men will do for a man." tions and suggestions perience behind them-and who have tors in the electrical industry, he said. Every mail brings letters from some of grown to prominence since the infancy the thousands of students of the Inter- of radio. national Correspondence Schools, telling of Don't wait till your set goes bad-get of this remarkable guide advancements won through spare -time study. FOR your copy to How much longer are you going to wait IN "RADIO NEWS" radio trouble now. Fill in the coupon we will return mail before taking the step that is bound to bring NOVEMBER and send you by a you more money? Isn't it better to start copy of The Radio Trouble Finder, a money -saving investment. You can now than to wait for years and then realize Special Television and "Radio -Movie" ar- man. what the delay has cost you? ticles-"Stereotelevision. " be your own service One hour after supper each night spent with the How to Build Your Television Receiver- I. C. S. in your own home will prepare you for the a Blueprint Article. position you want. Without cost, without obligation. The "Pre-Selector"-a Blueprint Article, The Copy mark and mail this coupon. Do it right nowt by S. Gordon Taylor. 25c The " Magnetic -Striction Oscillator "- INTERNATIONAL CORRESPONDENCE SCHOOLS with Constructional Data. "The Universal University" Bea 6166-F. Scranton. Penna. And many other practical articles on Without cost or obligation, please send me a copy of radio construction, short-wave reception, BUILD YOUR OWN your booklet, Who Wins and Why," and full particulars new radio apparatus, and radio theory. about the subject before which I have marked X: RADIO SET BUSINESS TRAINING COURSES Business Management Advertising 150 RADIO Initdstrial Management - English Personnel Management Business Correspondence D Trafic Management Show Card and Sign HOOK-UPS El Accounting and C. P. A. Lettering Coaching Stenography and Typing This is the latest ['Cost Accounting Civil Service Food Adulteration issue of this re- Rookkeeping D Railway Mail Clerk D Salesmanship Common School Subjects (Continued from page 611) markable book. D Secretarial Work High School Subjects Spanish French Illustrating D Cartooning Absolutely new - - TECHNICAL AND INDUSTRIAL COURSES S. and up to date. gElectrical Engineer D Architect All the best dr- I Electric Lighting D Architects' Blueprint s Mechanical Engineer D Contractor and Builder side of the spoon. Renovated butter (and cuits of the day. [I Mechanical Draftsman ['Architectural Draftsman oleomargarine) on the other hand, will Full instructions Machine Shop Practice 13 Concrete Builder also D Railroad Positions D Structural Engineer boil noisily, sputtering, and acting like a on how to build. Gas Engine Operating Chemistry D Pharmacy and but will yield Make your own Civil Engineer Mining ID Automobile Work mixture of grease water, D Surveying and Mapping ID Airplane Engines little or no foam. The difference in the set from the dia- Plumbing and Heating ['Agriculture and Poultry grams shown in v Steam Engineering D Radio ['Mathematics amounts of froth or foam is very marked, and acts as a conclusive test as to the nature 150 Radio Hook - Name of the butter. Ups. Write today - pick the set you want to build and make it. Then Street Address To distinguish between oleomargarine and either fresh butter or the renovated variety, you are sure to be satisfied with the City State pour about a cupful of milk in a wide - results you get. II you reside in Canada, send this coupon to the Interna- tional Correspondence Schools Canadian, Limited, Montreal mouthed bottle, and place in a vessel of 150 Radio Hook -Ups was prepared by boiling water. Add a spoonful of the but- the staff of Radio News. An accurate ter to the heated milk, and stir to melt it. guide to better set construction for the BIG VALUE for IO Cfs. remove the bottle and place in ice - radio "fans." 6 Songs, words and music; 25 Pic- Then tures Pretty Girls; 40 Ways to Make water, stirring thoroughly until the butter Money; 1 Joke Book; 1 Book on hardens. If the solid fat is in a granular Copy Love; 1 Magic Book , 1 Book Letter throughout the milk The Writing' 1 Dream Book and For- condition, and scattered 25c tune Teller; 1 Cook Book; 1 Base in small particles, then it is butter. If, on Ball Book, gives rules for games; 1 the other hand, the fat congeals into one MAIL THIS COUPON NOW Toy Maker Book; Language of solid lump, so that it may be removed bodily Flowers; 1 Morse Telegraph Alpha- bet; 12 Chemical Experiments; by the stirrer, then it is oleomargarine. CONSRAD CO., INC. Magic Age Table: Great North Pole 230 FIFTH AVENUE NEW YORK, N. Y. Game; 100 Conundrums; 3 Puzzles SOME ADULTERANTS IN MEAT 12 Games; 30 Verses for Autograph Albums. All the above by mail for 10 ctn. and 2 cts. postage. AS every housewife and every food CONSRAD COMPANY, INC. ROYAL SALES CO.. Desk 375 Norwalk. Conn. the most perish- 230 Fifth Avenue, New York, N. Y. handler knows, one of Gentlemen: able of all articles of our diet is meat. This Kindly send me a copy of 150 RADIO HOOK- in UPS...THE RADIO TROUBLE FINDER... t ,(CHEMISTS fact may he attributed to the presence (cheek which or both). the meat of all of the conditions that are Enclosed lind cents In full payment. /' Our new catalog, listing 5,000 the and development 2,500 illustrations, Lab- favorable for growth Name J Chemicals. of decay bacteria. To arrest this rapid , oratory Apparatus and 1,000 books, Address preservatives are , on receipt of 50e. spoiling, various chemical sent used, such as boric acid, benzoate of sodium, City State LABORATORY MATERIALS CO. salicylic acid and sulphurous acid. Their il 71st St., Chicago, U.S.A. 635 East Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928 655

detection involves the use of several more fir less common reagents. As a preservative for mince meat, catsup, jams and fruit jel:ies, benzoic acid, or its salt, benzoate of ;odium, is most widely Two 4 Room Houses Free. Built aey- in where in U. 8. Lot furnished. No obliga- used. To recognize its presence meat, tion. Not one cent of coat. A. R. Fisher. rub the sample with water and acidify with Batavia, Ill. Make 310-$25 daily showing Bent hydrochloric acid. Set the mixture aside ,Big Pay Evers Deis. Showing Nimrod's Make $500 before Xmas selling per - guaranteed All Wool Tailored to Individual All -Year Sellers! Dress, Work, and Flannel soma' Xmas Carda and Box Assortments. Measure 8ults-Overeoate,$23.50-$29.50. in an evaporating dish near a radiator or Shirts. Overalls, Pants, Sweaters. Under- Unequalled Values. Highest Commission. Sample Outfit Free. General Tailoring Co.. wear, Pajamas. Leather Coats, Lumbar- Samples Free. Doable Co. Fite/tissue. Mass. Dept. PCI 1. other warm spot, ccver from dust and allow Big 629 8. Franklin, Chicago. etc. Fes. noose. out Moaning Money -maker -521.00 deny. Women make $$ daily wearing and Ot aeeP1y Co Dept. 8ú. 4922-28 Men's suite, Your Lincoln Ave., Chiago. overcoats only $12.50. showing new Invention that prevents IGHT omen'sslon33.00.Blggestvalueseverehown. shoulder straps slipping. Real comfort at 8 STEEL'BLADE Men-Sell-Tp Leroy New Fall Winter Suits Wonderful value Fall Winter patterns. last! Free sample offer. lingerie "V" Co DEVELOPS A REDDISH Worthmore 919 -Oak St.,- North Windkaro. Conn. Sion o54 00. Customer's -SattetactionHint- Marceiwavermmie-W I. Taking American Agents earn big money taking orders DEPOSIT OF COPPER anteed. 6 Day Delivery Bales Outfit Free. Women by storm. Men andF women for our beautiful Drees Goods, SUM. Wash W Leroy Tailoring. 892 Broadway, ,., fepre- rite N.Y.., tethers everywhere making biggest Pro - Fabrics, Hosiery, Fancy Goods. 1000 sam- Mee $80 week. New educational in- fits of years. $279 a week. $57 a day. $17 an ples The National Importing Co.. version. Proctor earned $538 ash bonus 1 how' -spare or full time workers emu such .-L89, 573 Broadway, New York Clay. month, Freitag $500. McKean $20 In half omits «ally. Territories now being al- day. Playhox patented. Not sold in stores. lotted. Full Information free. Marcelwaver. Agents 3300raédtyers Hugedemand. finest line guaranteed hosier ever shown. Outfit Free. Patents Anemia- Dept. 985, Cincinnati. Ohio. 128 styles, colors. Finest silks. 35% com- tics. Dept. 20410, Pleasant Hid Ohio. America's Greatest Tailoring Line mission daily. Auto furnished. Fine silk hoes `pay my agents See a week lust to wear Free: 175 big samples-guaranteed Pure for your own use. Write for samples W11-. and show beau --Kul New FreeRalnooat and Virgin Wool -tailored to order-sensational knit Hosiery Co., Dent. 2635. Greenfield, O, give away Free Hats. Write for yams. low price. Blgcommlssions dally. Also cash R. H. King, 250 80. Wells. Chicago. bonus. Get outfit at onoe. Address Dept. Hotels Need Trained Executives. Na- 724, Geodwear. 844 Adams. Chicago. tics -wide demand for trained men and Show wonderful new Comfort Foot - Fig. 5. If your pickles appear to have a sus- women; pest experience We Mat to housewives and make $90 a wokt. piciously vivid green color, will ou by mall and punneeesery.In Soft, rubber rests aches this test tell withr big oppppoatttunities. Writit e at once fou or and while cookinge, washing,Ironing. if it is due to poisonous copper salts. particulars. Lewis Hotel Training Schools, etc. Aleo 47 other fast selling household Station BC -W'81, Washington, D. C. specialties. Free Outfit. Write quick. Kr!s- Laarlge shirt companywants mea to tee Mtg. Co.. 1412 Bar St., Akron. Ohioqu. to stand for a few so solution an Exclusive tory. active sr n t days, that the If youare wreliabosMd own In syelllingaKmaYzing 'Hook-Fastl" Delta to men. evaporates slowly. Beautiful towel, write Ralston Hall, Inc.. 156 1 Many uniquet«Lures. Liberal commission. crystals of Avenue. Desk A. New York, N. Y. Get facts and Free Belt Offer. Write Na- benzoic acid are formed, sometimes growing Agents $241 month. Sell Silk Hosiery. tional Crafts.. Dept. L-23, 41 John Ft.N.Y. Guaranteed 7 months. We furnish auto. Make 312 s day end liberal bonus sell - up to a height of one-half inch. If the Samples furnished. Free silk hosiery for log Pioneer 823.50 and $33.50 all -wool your own use. Write today, state else hose tailoring. Commissions paid daily. 100 amount of benzoate is small, extract by worn. Be tterknit Hosiery Co. Silk 2235. large cloth samples furnished. We train acidifying and shaking with chloroform, and CreenaeiA. Oko. the inexperienced. Write Pioneer Tailoring il0.ilate.iMBrOÀay/ Agents wanted to advertise our geode Co., Conferees & Throop, Dept. Y1272. Chi. set aside to evaporate slowly. The result and distribute free samples to consumers; I'll start you without a dollar. You 11 .000 an hour; write for full particars.t t1926 make 585 weekly taking ordersestorders for fin $85.N weekly -Drees« Free! Associate is the formation of benzoic acid crystals American Products Co.'.s Monmouth, tailored shirts and ties. Free (utfit. Dan company of famous Real Rik Hosiery offers above. Cincinnati, O. Reilly, 1237M Broadway, N. Y. you remarkable opportunity to earn money. as $3.88gommission Faria styles. Below-etore prices. Free equip. To test for boric acid or borax, fre- SSiite! Anyone can sell! Big a In meeIndIanat.Hanfopolle.rd Frocks. 915 Walnut 8t., advance! Free Sales,or Kitt The 888 Com- quently found as a preservative in sausage, pany Dept. CL15 Fort Wayne, Ind. Agents. Get Vanilla kktrect at one- Get Our Free Sample Case-Toilet Ar- eent a bottle. Also new Black Walnut butter and milk, we use turmeric paper, made ticles, Perfumes and Specialties. Wonder - Flavor and sixty other produets. Welesme by cutting filter paper into strips, dipping Le Derma Co.. Dept. RC, Extracts Harvey. Illinois. Bt. Iouls, Mó Punchboard Salesman -8251 weekly into tincture of turmeric, and drying. It A Paying Potation Open 90 complete deals. Elet machines of to repreeentat ve of character. (Take or- zay.kinds. Most gigantic line ever festered. is on sale in the chemical supply stores. Rub ders shoes -hosiery direct to wearer. Good Repeat comma. Beautiful 4 color catalog the meat Income. Permanent. Write for free book free. Lion Mfg., 2146 Shemeld, Chicago. thoroughly with water and filter Getting Ahead." Tanners Flue Mfg. B ankrupt -Rummage Sales make- 55ái to remove the solid part. Add five drops Co.. 10010 C St., Boston. Mass. monthly. We start you, furwehing yon Make $95 «week, $3 ea hour. wlthfam- everything. Eno. unnee. Write: Robey.. of hydrochloric acid, dip a strip of turmeric ens World's Star Battery. Lingerie. Under- Dept. R-10, 1945 Mehaada Ave., Chicago. wear for men, women, children. Amazing 575. Weekly -Selling nationally known, paper into the liquid, remove, and warm values. Big profits, repeat business ca tailored -to-measure $23.50 suits, overeat'. over a Bunsen burner: The formation of bonus. Free sellingng equipment. Write Quality unexcelled. Commlemon $4.00, plus aaulek for territory. World Star Knitting Profit Sharing. Powerful sales producing a bright, almost cherry -red color on drying Co.. 162 Lake St. Bay City. Me.Sell outfit furnished. Style -Center. Dept. PCS, shows beautiful "Style Tailored" shirts Cincinnati, O. boric acid or borax. Pour one drop and neckties direct to wearer at money- ME L+vYERekmbOFU Wavy Hair In 10 minutes. "Waves.' saving factory prices. Many beginners earn new wonder preparation ehangesstraightmt of ammonia on the paper, and the color 350 first week in spare time. 3100 weekly hair Into lustrous. soft waves. Sensation of changes to dark green or greenish black. full time easy. Selling outfit tree. Howard New York. Be your own hairdresser. Abso- Phlrts, 1213 Vkp Buren, Fan. 27, Cnimgo. Manes Suitstil.45lLook, FeelLlkeWonit lutely greaseless and harmless. Large bottle Sulphides are sometimes employed to Wear like lroni Workmanship Fit. Guaran- sent postpaid on receipt of $1.00. Beauty Federal Dlstrlbuton Get Big PaytTlo teed! 8.2.50 Commlssiont Free F7ta-U- capital or exppeer needed. Terr. being as- Kitt Co., 365 H Lincoln Place, Brooklyn, N. Y. "doctor up" sausage and chopped meat. The signed. Write fur application Federal Tailors, Dept. 291C, South Whitley, Ind. week easy beautiful blank. We Start You A Soaps, MAa introducing test for this adulterant is simple. Macerate Pure Food Co.,. W 2311 Archer, Cbiago. Without Dollar, Une of women's dresses. Smartest aiylea it's Legal. New and Aplenty Difeeent! Extracts, Perfumes -Toilet Goods, experi- ether le low price gets orden tmmedh the sample with water, add several pieces Gypsy." It's whirling wheels fascinate ence unnecessary.. Carnation Co.. Dept. ateiy. FFce ceiling outfit. Free Dressss. everybody. Merchants buy eagerly. Clean 593, Pt. Louis, Mo. Fashion Frocks, Dept. X -I1. Cincinnati, O. of pure zinc and about five c.c. of hydro- up $100-3150 weekly. Cigar Store, Dept. Agents -big Money Selling Model Hats Don't Sell tor Others. Employ Agents P, Peoria, In. ,.. for men. Guaranteed quality; low prices. 20 yourself. Make your own products. Toilet chloric acid. If sulphides are present, hy- numbers; smartest styles. Free Outfit. Articles, Household Specialties, ete. 500% drogen sulphide will be liberated, which will Model Hat Co., Dept. M-27, heat Orange, profit. Valuable booklet Free. National N. J. Scientifie labs.. 1929 W,: road, Rich- readily be recognized by its characteristic New Insentient Keep phone and iron mond Va. , cord from tangling and amnmg. Prevent big Pay Jobe in Automotive field. Be- "rotten egg" odor. To confirm the test, iron marching. Save electricity. i g$ dailyen come expert, using real equipment with dip a piece of filter paper a solution of Sample free. everknot Dept. 1 1-Z, 4503 real shop tole in eight weeks. Satisfaction into Ravenswood, Chicago. H1. guaranteed. Write quick for special tu- lead acetate, and suspend over the mixture. Mee who like to travel. Work romantic Ilion offer. McSw eny Auto Schools, Dept. South America. American firms pay fare. 21-H, Cleveland, O. and Cincinnati, O. A black or brown coloration on the paper expenses. Free list. South American Service Learn drugless heeling at home. In- Bureau, 14800 Alma. Detroit, Mich. temeting, very profitable profession quickly indicates the presence of hydrogen sulphide. boys and Girls-Earn Xmas Money. learned by spare time home atdy. MU - Write for 50 Seta St.'Nleholaa Xmas Seals. lions of patients walling. Practise in your ARE "DYED" FOODS HARMFUL? Sell for 10c. a set. When sold send us $3.00 own or patient's home. Earn while you and keep 32.00. St. Nicholas Seat Co.. learn. Quick new method of teaching by Dept. 385 P.C.S., Brooklyn, N. Y. use of motion pictures. Send 4e postage THERE is another method of falsifying Kara -315.N daily selling personal for Free Introductory course. American food, and making it appear better than Christmas cards made to order the most University. 500 No. Dearborn, Chicago en wut »ballen beautiful and complete Sne selling at ex- Want U. S. Gov't Position: Commence it is, or of simulating wholesome foods with ceptionally low prioa High commis- 5115-$250 month. Men -women, 18-55, re : alone dipare al,: etcerle tw um trained at home In three weeks. Write a combination of entirely foreign substances. full raid me. write today rumple Osmeet's Instruction Bureau, 137, St. -tar of which there is an end - Great neckwear line now free! Features book: Big season on. Klein Co., 242 North Louie. Mo. The coal dyes, finest quality neckwear at factory Vic.es Water, Rochester, N. Y. -- Men. get Forest Rangers lob; $125-3200 Big commissions daily. Write for FREE Sell New Alligator and Tu-t.olor Lea - month and home furnished: hunt. ash, trap. tie offer and FREE outfit. Nawco Neck- tperette Coats. Big Variety. $2.65 up. PURE ADULTERATED wear, Hat For details, write Norton Institute, 1623 N-125. Covington, Ky. - Free. 515 deny sure. New Fall outfit Fro. Temple Court, Denver, Colo. COFFEE Bang -Up Good New Sideline! Sells Sllvertone, 2035 Charleston. Chicago. Men-Qualify for Railway Mall Clerk. Everywhere all Merchants, Banks, Mfrs., Pert -time workers wanted. A limited Post Office Clerk. Carrier and Park Ranger FLOATS WATER 'VOT COFFEE SETTLES Big Comma. advanced daily. Pocket Out- number of positions open for direct sale - poeitions. Steady work. Vacations. Particu- fit tree. Carrell, 319..N. Dept. COLORED Albany, men. Next 3 big Iss ues of my bookcontain- lars Mokane Inst., 733 Denver, Colo. VA, Chicago. - lug valuable opportunities on spare -time Candies, Home Made. Make big WATER Permanent Business Your Owe: Men money making sent for only 10e. Albert money. Few dollars starts you. We teeth and Women. its to 3100 weekly operating Bernard, 22 E. 12th Pt., Cincinnati, Ohio. making and selling. Capitol Candy School, COLORED 8pedaltyCaady Factory."Welnatruetand Sell Candy Specialties to Stores. big Dept. AG -8545, Washington, D. C. BROWN furnishupaar-set imé few dollars you into wholesale burdnera Booklet free. Buyer make $18every day. Plane free. Lawren ce Ragsdale, Drawer 40, East Orange, N. J. Marble, Richmond, Va. AC Red loseta tubes. supplles wholesale $31 Profit -with 31.50 Outfit -big to Agents. Elections, television, short wave. Money -Easy Work. Sell Gold Monograms u boost sales. Get Radio Guide free. 2011s for Automobile) & Luggage. No experience. tubes 39c. Banwlk, 5 Canal Sta. Chicago. No license. Send 31.50 for coin lete outfit. Make 51000 tefore Xmas selling exclu- Nulife Monograms, Hartford, Coon. give personal Xmas cards In distin;tive if you need money and want to make It steel -engraved designs. Expensive sample at home In spare time get my big illustrated Fig. 6. You may d stinguish the pure from book tree. Wetmore, Jane & Sudden. Dept. book of 67 tested plans that show you how the adulterated coffee, by observing P. C. S., Roct ester. N. Y. to start earning a profitable Income without its be- Selling Like Blazes! 11 -piece Toilet investment. Mall only half dollar (stamps . havior ïin cold water. Goods Assortment at 32.25, with 2 -piece or coin) to V. O. Fisher, 795 Kearney Ave., carving set free to your customers. 100% Arlington. N. J. - profit. E. M. Davis. Dept. 612, 234 W. Become Successful and Independent. likroEarte8egáe u less variety, lend themselves North Ave.. Chicago. III. Complete National Success Course In bust. very readily Men. Enter U.S. Mall Service; $142-3225 new and personal efficiency trains you for Weekly paid 5100 -Yours -At Once. to the coloring of foods and beverages. month; steady; vacations: experience Big Money lobe. Offered to you at the Take orders for America's foremost Une unnecessary. For details, write Norton amazingly low special price of 31.98. Oriel. Shirts, Neckwear, Underwear. Experience There is considerable difference of opinion lust, 1523 Temple Court,. Denver, (lolo. sally 324.00. Only few courses left. Order unnecessary. Outfit free. Carlton Mills. among food scientists Fifth Avenue Manufacturer Sells Di- today. Pay postman 31.98 plus few cents Dept. 2R. 114 Fifth Ave.. New York City. whether all the ma- recd-Sults. Topcoats, overwrite $13.75, post. Consrad Co.. 230-E 5th Ave.. N. Y. cogs by nothing to investigate. Every company terials used for coloring foods are injurious commission $1.50. Guaranteed All Wool 35$ daily being made our Neckwear g(ses details of ils proposition FREE. Wale and Worsted Suits, Overcoats 319.75. nom- Jobbers. I will send you four plans to build for Mom which interest pila. to the body. But there is little doubt in mission 34.00. Satisfaction or money back a wholesale business of your own absolutely "oar. Free tutet. Dept. PCN. Avenue Free. Write Alfred Ralston Ave., Publishers Classified Service regard to the effect of many of these dyes, Tailors, 140 Fifth Ave., New York,, New York. N.Y. Dept-- E. 44th St., New York (Continued on page 657) Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com (5( Science and Invention for November, 1928

Books gwno Home should be without

HOUDINI'S SPIRIT EXPOSES the hair, the eyebrows and lashes; adding that extra pound or taking off and excessive weight-all is covered. DUNNINGER'S PSYCHICAL BEAUTY SECRETS should be every woman's constant companion at INVESTIGATIONS the boudoir. Critics the country over By JOSEPH DUNNINGER have claimed that a fair price for a book of this kind would be from three to five In this remarkable new book the voice dollars. However, due to our unique of Houdini has been resurrected, as way of publishing, we are able to give though from the dead, and can be heard this book to you at the phenomenally to echo again in sullen denunciation of low price of - the ever-increasing number of spiritualistic mediums who, since his de- cease, have been parasitically bleeding the innocent public of its choicest pos- 50c sessions whilst posing in the sacrilegious Per Copy guise of the living dead. Joseph Dunninger, famous magician, Sold at all newsstands or Chairman of the Science and Invention write direct -112 pages-fully Investigating Committee for Psychical illustrated-large magazine size Research and the author of several notable works on magic, was a close personal friend of the late Harry Hou- dini. All the data appearing in this POPULAR CARD TRICKS was from the personal book taken By WALTER B. GIBSON notes of the dead magician now in the possession of Dunninger. These and Pleasant Entertainment for All the accompanying remarkable conclusions drawn from the various success- Walter B. Gibson has written what ful exposés of Houdini, together with is conceded to be the most complete the tremendously interesting revela- book of card tricks ever published. tions contained in Dunninger's Psy- There are literally hundreds of these chical investigations, make this a book clever little tricks. You need not be that all should read. Over 116 pages. a professional in order to work them Large 9x12 -inch size. out. There is no sleight-of-hand required. You can do any of them with Only little or no practice. Simple to perform-difficult to guess. Complete instructions - hundreds of illustrations. 50c Once you have mastered a few of the Per Copy tricks that this book contains you will become extremely popular-always At all newsstands entertaining. Imagine the fun you can or write direct have at a party. Just nonchalantly pick up a deck of cards and inquire if anyone has "seen this one." Then, BEAUTY SECRETS while all attention is focused on you one after another to the By EVA NAGEL WOLF do these tricks admiration and wonderment of all. This book, by Eva Nagel Wolf, prominent editor of the beauty column This big book of entertain- of one of the leading women's magazines ment, fully illustrated-large and internationally known authority, magazine size divulges to seekers of beauty the true secrets of their type-just what is nec- Only essary to make themselves most attractive. "BEAi:TV," says \li>- Wolf, "is not difficult to obtain once 25c you have learned the simple secrets of type." It is the purpose of this book Per Copy to pass on to every woman these secrets-to show her the quickest and easiest way to genuine beauty and at- At all newsstands tractiveness. or write direct There is nothing left unsaid-every phase of beauty culture is fully treated. The art of make-up, care of the hands, I EXPERIMENTER PUBLISHING 230 Fifth Avenue New York, N. Y.

Please sal' you s a zz. it in SCIENCE and INVENTION

www.americanradiohistory.com Sczence and Invention for November, 1928 657

Food Adulteration (Continued front page 655)

as they are known to be harmful. The U. S. Department of Agriculture, after a careful examination, has approved of the use of eight aniline, or coal -tar colors, which are known as "certified dyes." However, Tine Greatest Automotive the use of even these approved materials Discovery of Scientists in Recent Years may constitute a fraud, if they are em- You just flow ReNUZit onto any automobile with a piece of cheesecloth, and instantly the ORIGINAL ployed to give a false appearance to the color and lustre of that car is like new again! foods containing them. NOT A POLISH. CLEANER, WAX, OR PAINT Coloring matter may No tiresome r-sbbing or polishing; harmless, lasting. sure. be added to jams and jellies made from in- AGENTS' NEW PLAN ferior substances, so as to give them the same appearance as those made from fresh RiNt Zit Make $50.00 a Day fruits. Dyes may be added to tomato cat- Ser, ice Stat ions Millions are waiting to buy sup and pickles to restore the original color Bring ReNUZII. That is why Re- which has been lost in the process of can- $1,000 a Month NUZit Agents all over the country can make almost un- ning. Artificial coloring matter is often Now Comes the It is easy to see believable profits. And our added to butter. Frequently chopped meats why so many men PROPOSITION is so GOOD can get into the that you should have no trouble which are no longer fresh may be treated big money class making $50.00 a day and up. with red to operating ReNUZit a dye give them the appearance New Shorthand Service Stations. of fresh meat. Write for the thrill- Test ReNUZit Free! ing story of Re- To test fruit products, as well as any NUZit and your 'You have the privilege of try- R YEARS there has been a crying need wonderful oppor- ing ReNUZit yourself right now other foods, for artificial coloring matter for a new system of shorthand-for a really tunity to make without risk. Prove to yourself heat a small quantity in boiling $12,000.00 a yeas. what miracles it accomplishes. with water. modern system, a scientific system-one Do it Now! Write TODAY for full details Place in this liquid a small woolen cloth. that could be written more RAPIDLY than and Free Test Offer. Boil for five to ten minutes, stirring occa- the conventional sign systems, that would be sionally. Remove the cloth and wash in hot more ACCURATE-and that could be THE RENUZIT SYSTEM water. If the cloth is brightly colored, the learned EASILY 1154 E. ERIE ST. Dept. 863-P.R. CHICAGO, and QUICKLY. ILL. presence of artificial dyes is shown. Natural colors give a dull, pinkish brown tinge. Now at last it is here-the new. shorthand. The Magnified 225 Diameters business world has hailed it with enthusiasm. Al- While on the subject of artificial color- ready it is saving time and increasing efficiency in his is what the tip of a fly's leg ing materials, is offices everywhere. Busy executives are using it s like when seen through the it interesting to note that salts of copper are sometimes used to im- themselves. So are professional men and women, Ultralens lawyers, writers, clergymen, public speakers, engi- part an intense green hue to imitate the neers, doctors, reporters; Students. Experienced Microscope natural green as in peas, green beans, brus- stenographers as well as beginners are adopting it. At last a high powered micro- sels sprouts and pickles. Since copper salts scope is within are highly poisonous, the means of all the danger in this who wish to form of adulteration is readily seen. To study, observe and experiment prove the presence of this adulterant add with the vast one or two drops of hydrochloric acid, mix ,The 'NATURAL SHORTHAND world of minute si objects invisible thoroughly, and place a bright steel object, to the naked eye. such as a knife blade, into the solution. A You use only the ordinary letters of the alphabet- $3.00 for Comple-e Outfit Prepaid Such fun It is, the sanie ABC's you have always used. Speedwriting as well as educa- reddish deposit of copper will indicate that tional. No technical training required, hundreds of is simply- a scientific condensation of the English scientists and teachers are using this instrument. Gives salts of that metal have been used in the language, based on your natural habits of speech. enormous magnificarion and perfect definition. Send $5.00 food. Or filter off the solid for complete outfit. Send for descriptive literature. and add ammonia to the liquid. A bright blue color Quickly Learned at Home ROAT & LOHM4N, Dept.203, Milton, Pennsylvania indicates copper. Cheese cloth will answer for filtering through. No need to memorize a "foreign language" of dots Course for men of ambl- and dashes, hooks and curves. Once you understand don and limited time. As a thickening agent in cheap jellies thejsimple, scientific principle of Speedwriting, you Electrical Over 5000 men trained. can start using it almost at once. Amazing speed is Condensed course In Theoretical and Practical Elec- starch is sometimes used. Dissolve a sample quickly developed. Speedwriting was originated by including in water, heat to boiling, and add potassium Miss Emma B. Dearborn, famous authority on trical the close- Engineering ly related permanganate solution, drop by drop, stir- shorthand. She has taught practically all systems subjects of Mathematics and Mechanical Drawing. for eighteen years in such institutions as Columbia Students construct motors, install wiring, test elec- ring constantly until the solution is almost University, Rochester Business Institute, Simmons trical machinery. Course designed to be completed colorless. Cool the liquid completely and College and the University bf California. in one college year. add a drop or two of iodine. The character- BLISS istic blue color proves that starch is present. Send for Free Book ELECTRICAL SCHOOL Prepare for your profession in nil Saccharin acts slightly as a preservative, Let us tell you more about Spetdwriting-how employ- most interesting city in the wand. but more especially as a sweetening agent, ers are requesting their experienced stenographers to Catalog on request. learn it-how they are employing beginners who have 151 Takoma Ave.. Washington, D.C. having about five hundred times the sweet- studied it-how presidents of firms, sales managers and other important executives have learned Speed - ening power of cane sugar. In many states writing themselves in order to jot down their valuable its use is prohibited by law, on the ground thoughts when no stenographer is at hand-how all kinds Of professional men, college students and office that it takes the place of sugar which is a workers are increasing their efficiency through Speed - writing. The booklet Itere offered will give you detailed valuable nutrient, and that it may have an information and explain fully just what Speedwriting injurious effect on the system if taken con- can do for YOU. Also tells how you can learn Speed EASY TO LEARN WATCH TYPING at home. SEND FOR IT NOW! MAI, ING and watch and clock tinuously. This adulterant is tested for repairing by our practical as follows :-Mix the jam with water to BRIEF ENGLISH INC. method of individual training. SYSTEMS, EARN UP TO form a solution, and shake with a small Dept. L208 quantity of chloroform. The latter, $100 A WEEK which 200 Madison Avenue, New York City Learn in few months to fill big dissolves the saccharin and not the sugar, paye to or starts usi- settles to the bottom and is removed by Offices also at FREE BOOK Big shortage of tinownted Toronto, Ontario, watchmakers. Da- or evening school. No books or chimes. means of a medicine dropper. Evaporate the Canada London, England You can earn pan of your tuition on actual repair work you do in school. Write for Free Book Today! chloroform solution by gentle heat. The NATIONAL SCHOOL OF WATCHMAKING distinct sweet taste of the residue proves 1340 South Miciigan Ave., Dept. 38, Chicago, 111. BRIEF ENGLiSIi SYSTEMS, INC., that saccharin was used ill the food. Dept. L208. 200 Madison Avenue Another sugar substitute used in jams, New York City. 22Cal jellies and candies is glucose, which is tested Gentlemen: Without cost or obligation, I should like to 6Shot receive a copy of your Interesting Booklet on Speed- for ill the following manner :-Mix the food writing. The Natural Shorthand. Ä omatic il\ with water, warm the solution, filter lime Areal and Shootsiive loud-powerfulloud-po erful cool. Add an equal volume of strong al- st uctiln, automaticab c fore Con- Name efenioe. finish, .fun cohol. pure Frigh,nstves.trdurability-Me for sell If sugar was used there will yo ce.Erie F s. Guar ed a, tram s, dogs-fool your friends.oa. C agazined absolutely safe. Auto- be little or no precipitate. If glucose is matically loads sauna andejects.55. rtCartl Fade money. er_ onarrive!6 $4.99. 100 cartges given present a dense white precipitate of dextrin Address Federal Mail Order Crp, 561 Broadway. N.Y.C.. Dept. 8118 forms, which settles to the bottom after NO REQUIRED PERMIIorLICENSE a time. City State Please say 3'ou saw it in SCIENCE and INVENTION

www.americanradiohistory.com 658 Science and Invention for November, 1928

VANILLA EXTRACT MINUS THE VANILLA A\LONG the flavoring extracts, that of foOCLEARED vanilla and lemon are most extensively used. In the case of the first, a large pro- So writes W. H. Adams of Ohio. Letter portion of the extracts on the market are from California man reports $11275 sales not made from the vanilla bean at all, but in three months; New Jersey $4000 pro- from artificial vanillin and coumarin, with fits in two months; Pennsylvania $3000 some coloring matter and sugar, added to profits in four months. Ira Shook $365 a weak solution of the Tonka bean. The test sales in one day. Bram bought one outfit consists of evaporating down some of the April 5 and 7 more by August. Iwata extract on a water bath to about half its bought one outfit and 10 more within a year. J. R. Bert says "only thing I ever volume. Add cold water to make up the bought that equaled advertisement." John original amount. By this treatment the Culp says: "Everything going lovely. alcohol of the extract will be driven off, Crispette wrappers all over town. in is It's a ood old world after all". and the watery solution that left the Kellog, $700 ahead substances ill true vanilla are nearly insolu- nd of second week. ble, so that the liquid will be cloudy, and have a dirty brownish color. The artificial extract, on the other hand, will be bright Wholesale or retail. Big profita and clear. either way. No As an adulterant, to imitate the natural town too small. Business is color ill flavoring extracts, caramel is fre- pleasant, fasci- quently used. It is also commonly employed nating and dignified. You wherever it is desired to produce a red or manufacture brownish color in foods. It is made by a food product heating sugar to a high temperature, which WE START YOU IN BUSINESS results in a partial decomposition, and a loss Furnish secret formulas, raw material and equip- of most of its sweet taste and its solubility. ment. Little capital required; no experience needed. Iu testing for caramel, choose two test - Build a Business of Your Own With tubes of equal size, and put a sample of the No limit to the sale of Crispettes. Everybody likes Violet Ray extract in each. Add one teaspoonful of them. It's a delicious food confection. Write for Fuller's earth (obtainable at your drug facts about a business that will make you independ- Vibration store) to one tube, shake thoroughly for ent. Start now, in your own town. several minutes, and filter. Compare the Profits $1000 a Month Easily Possible Ozone Send postal for illustrated book of facts. It contains filtrate with the untreated sample. If a enthusiastic letters from others-shows their places Medical Electricity large part of the color is lost, it proves of business, tells how and when to start, and all im- The Four Greatest that caramel is present, since Fuller's earth formation needed, Free. Write now! has the property of removing this material. LONG-EAKINS COMPANY Curative Powers 1153 High Street Springfield, Ohio Generated by This Lemon extract is made by dissolving oil of lemon in strong alcohol. On dilution the oil is precipitated to produce a milky Great New, appearance in the liquid. To test, mix one part of extract with three parts of water. If real lemon oil is present it will he thrown Invention! out of solution, and will give the liquid a Elco Health Gener- turbid appearance. Later the oil will form ators at last arc a layer on top of the water. If the solu- Get our big new ready for you! If tion remains clear with 1929 Radio Catalog- you want more health after diluting water, het off the press. Con- -ggreater power to en - very little or no oil of lemon is present. tains thousands of amazing the easures an bargains. Latest, nationally delightsabout you, or ad- if more beauty is your MISCELLANEOUS ADULTERANTS vertised Radio equipment. Latest desire-writel Ask for In Ham Transmission equipment. the book on these in- Everything at lowest wholesale prices. ventions which has AFORM of adulteration which is com- just been prepared. It monly practiced is the addition of for- NEW RADIO Prizes will be sent to you CLUB-Big without cost. It tells eign material to ground coffee, such sub- Get all the facts about "Ether Trappers" , you how Elco Health stances being employed as chicory, caramel, Club, now. No dues. Many advantages. A ,fin- Generators aid you Writeemher- rte_ leaving the leth- peas and roasted grains as corn, wheat and FREE i51 argy and hopeless- M ness of bad health rye. A simple method of detection is to ship at once. endweaknesabehind This Big Book money- le forever. Re -vitalize shake the sample with cold water and let of ,..renneeepiezewegit Bring it settle. Pure coffee contains a large saving bargains is yours backve Writ. todahollyBe FREE. A regular Radio alive. write today! amount of oil, therefore most of the par- encyclopedia. Write today Here's What Elco Users Say- ticles will float. Nearly all coffee substi- for your copy of this book. 'Wouldn't take $1000 for my les." tutes are heavier than water, and sink, car- AMERICAN RADIO & MERC. CO. ' lias done me more good In 2 weeks Dept. 27 than doctors did in3 years," "Cured rying along some of real my Rheumatism." My Eceema the coffee, and American Radio Building coloring the KANSAS CITY, MO. bie f' "Curedmyweyeomen':ken, Now water with a brownish tinge. i sloop soundly all night." 'Thenke If there is a large deposit sediment, to Eico s and vigor e of the hack." ..No more wn." 'Colds never bother me now." "Chronic coffee is adulterated. Since coffee contains Constipation baalehed." no starch, while the cereal and legume These great new inventions generate Violet Rand Vibra- adulterants (as corn, peas and beans) have ENJOY ee THRILL 9T,LECTRIFIED Electricity par Ozone -combinedtion,one or separate. Freeree Trial large quantities of this nutrient, a chemical They operate on the electric light in your home or on test may also be performed. Boil the coffee RADIO at SMALL COST their own motive power at less than 60 cents per year. with water for two or three minutes. Filter, Elco Health Generators are positively the only instru- Banish forever all the annoyance ments which can give you in one outfit Electricity, cool completely, and add a drop of iodine. and expense of buying new Violet Ray-Vibration and Ozone-the four greatest "B" agents. Send coupon The well-known deep blue color will indi- 8! Batteries with a TOWNSEND "B" curative the compiei POWER UNIT. Hooked up in a below. Get the Free Book NOW l cate the presence of a starchy adulterant. few momenta-and you have permanent power from your light soc- Cotton seed oil may be found mixed with 4=2131 ket from that time on. Use same Mail tubes now in your set. No changes. Coupon olive oil in more or less considerable quan- You'll be amazed at the ( tities, although the ease with which this way Townsends improve for Free Book your reception and add to Do not put this paper down with- foreign material may be detected has dis- distance getting. More out os ar,edhepi,noonod Don't than 60,000 now in use. ith almost couraged its widespread use. To test, use Send Coupon today for full o life and energy. You owe It to your- Halphen's reagent which be information and free trial self to be a better man or woman. You can obtained offer. put here to enjoy life-not just already mixed, or can be toedreg through It. So. do not rest an- prepared very TOWNSEND other der until you have puY r name easily as a on the coupon bore. That will b g the whole story of these follows:-Dissolve one-third of LABORATORIES great new inventions. Do it today - sow. teaspoonful of finely divided sulphur ill Chicago Illinois Lindstrom & Company three or four ounces of carbon bisulphide --COUPON------Ave., Dept. 14.28, TOWNSEND LABORATORIES I1-28 2322 Indiana Chicago and mix with an equal volume of fusel oil Dept. Pleas° send me your free book, "fié lt-Power-Beauty" and 35 , 713 Townsend St., Chicago, Ili. full information of your 10-day Free Trial Offer. (amyl, alcohol). This reagent should be Please send me full information on the Townsend "B" handled with great care because it is highly Power and Free Trial Offer. Nance inflammable. To some of the oil to be ex- Name amined add an equal Address volume of the reagent Address in a test tube and heat carefully for fifteen mnutes ill a vessel of boiling salt solution, Please sa v doll satt' it in SCIENCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928 ()5`)

consisting of a tablespóonful of salt in a pint of water. If there is even a small percentage of cotton seed oil, a distinct reddish color will appear. If the sample YOU Zfje igreater5 is all or nearly all cotton seed oil, the re- Would 6iv& sulting color will be a deep red. I9g TESTING CANNED FOODS Gain ATREATISE on food adulteration is to not complete without a passing reference to the subject of canned goods and the foreign matter which, accidentally or otherwise, may find its way into the foods. The a NIGH SCHOOL process of food preservation by canning, or protecting from air and sterilizing, has developed to an enormous extent in this country. Fortunately, most of the food is prepared in such a way as to be entirely whole- EDUCATION? some. Occasionally we find a can, the contents of which have begun to spoil or fer- Here is the most sensational educa- ment, with the generation of gases, and a tional offer we have ever beard of! consequent swelling or bulging of the can. A High School education for only Formerly it was not an uncommon practice $19.85. Think of it! And even this for manufacturers to puncture these "swells," small amount is payable on such easy on. the Oceanfront and reheat them to stop fermentation, and terms that you won't miss the money. afterward solder them again, and put them YOU can gain this valuable training in your on the market. own home, in your spare time, through the Atlantic City, N. J. It is not unusual to find salts of tin, iron most enjoyable method ever devised. You merely and lead in canned products, due to the read interesting questions and their fascinating, action of the acid fruits on the tin plate of enlightening answers, on every High School sub- PREFERRED- which the can is composed. To show the ject. You may examine the entiré Course on presence of iron in canned fruit, test some approval without sending a penny in advance. In Winter and all seasons of the juice from an old can of fruit with See offer below. a little of a strong infusion of tea. Since These famous Question and Answer Books by those who know and the tea contains tannic acid, it will form a are used and endorsed by thousands of students wish the best upon either black coloration (which is nothing more of all ages, as well as by over 12,000 High than INK!) with the iron that has been School Teachers and Principals throughout the American or European dissolved from the tin plate by the acid of the country, because they really teach, in the the fruit. most interesting way. Plan-Sensible rates withal. With a fundamental understanding of the No one realizes better than you what it has nature of some common food adulterations, cost you to have missed high school; and no HILLMAN MANAGEMENT and with the inquisitive mind of a scientist one knows better than you what your lack of and experimenter, the amateur chemist has a high school education -trill cost you in the before him a romantic as well as highly years to come-if you do not acquire it. Why instructive field of research. Dozens of not make up for lost time this easy, con- When in Washington visit foods and food products that are used daily venient, interesting and economical way? in the home may contain some foreign ele- Harvey's Restaurant, zith and ments that are likely to be injurious to How You Are Taught Pennsylvania Avenues the health. Or, if the danger be not so serious, the adulterated food may still be Each book contains zoo to 30o questions and their boiled -down, simplified answers. You are taught one FAMOUS SINCE I858 an inferior product for which he is paying fact or law or principle at a time, in easily understood the higher price of the genuine article. language, on fifteen high school subjects: Ancient Whichever the case, the ambitious home History, Biology, American History, Civics, Arithmetic, experimenter will derive more than a super- Elementary Algebra, Physics, Modern History, Litera- cial profit from an application of these ture, Economics, Geography, Latin, Physiography, fairly elementary tests for food adulterants. English Grammar, and Spelling. The fifteen books contain'the equivalent of all you can learn in a four-year High School Course of approx- 50,000 imately 625 days' attendance, or 3,84o hours. Yet by spending only fifteen minutes a day with these Ques- FEET OF RADIO tions and Answers you can complete them in a few 50,000 square feet of floor space Danger-High Vacuum months. in a large modern building de- (Continued from rage 601) voted exclusively to radio. Tre- FREE EXAMINATION- mendous stock of latest kits, parts and sets in improved de- Send No Money signs and styles. Write for Cata- almost complete collapse. The steam had Before you pay a penny, see for yourself how easy it log "D-1." Wholesale Prices. condensed, forming a partial vacuum, and is to acquire high school training this new, easy way. the outside air pressure had simply forced The coupon will bring you the fifteen famous Blue in the sides. Books to examine free. Keep'them and enjoy them for 5 days. Then decide. You take absolutely no risk; you Allied t'Radio Michael Faraday, the inventor of the assume no obligation by mailing the coupon.-High CORPORATION many years ago performed a simple 711 W. LAKE STREET, CHICAGO dynamo, School Home Study Bureau, Dept. X2411, 31 Union experiment before one of his lecture classes. Square, New York City, N. Y. He placed a thin tin vessel, containing a small amount of water, and equipped with a NKOGRAPH PÓ NTEDPEN r stop -cock, over a flame.Raising the water IO DAY FREETRILL $ Write. with Ink a, oobiy. " - to the boiling point, he allowed it to generate ing Purpose o: Den endapenc SAME SIZE AS steam until the steam had driven out what scratches, leeeordreete.. Makes 3 carbon $ 7 AND $873 air was originally in the vessel. He then Copies at one time FOUNTAIN closed the stop -cock and removed the flame withoriginalin.nk. PENS ew¡u¡.a°OM r. SENDN 111ONEY.Paypoetn,antt .50 from beneath the vessel. In a few moments h Ileum__ plus postage. Sent prepaid if cash le Bent with order. Money back if not eat. the steam remaining in the vessel had con- pewra in lefled,witkin 10 days. Nam. PM« jignmegium COMPANY. INC. densed and the light metal was crumpled as zoo-543 Centre M.. New York by a giant hand. Sir Wm. Bragg, the noted Send for Gkegra b or write for Sale. plan booklet. Big value. sells on eight no investment. English shows - - physicist, the same experi- High School Home Study Bureau, Inc. in ment in photos his popular book, "Con- Dept. X2411, 31 Union Square, New York City. cerning the Nature of Things." Thus, on the Gentlemen: You may send me, for FREE EXAMINATION, laboratory scale, we have an exact reproduc- the 15 famous Blue Books, containing the equivalent of a four-year High School Education. Within 5 days I will tion of what happened in the case of the either return the books or remit 53.85 as first, payment and larger and more strongly constructed cream then $4 a month for four months. a total of 519.85. can. Name Wonderful, new devise, guides your hand: corrects your writing in few days. Big improvement In three Address hours No failures. Complete outline FREE. But even a well-built cream can, con- Perfect Penmanship Inst., Dept. 44, St. Louis, Mo. structed for rough handling and general Town State Please say you saga it in SCIENCE and INVEN T I-0 N

www.americanradiohistory.com 660 Science and Invention for November, 1929

abuse, might just as well have been made of paper for all its strength as compared to that of the air. Everyone knows that air exerts about fifteen pounds pressure per square inch on the surface of the earth and upon every living and inanimate thing upon n. the earth. But for a like pressure exerted ORIGINAL outwardly from within our bodies, we would CHEMICAL be crushed by these mighty forces. If the OUTFIT cream can shown, had of been submerged in five feet o fmolten iron (and some means provided to keep it from melting) the pressure would have been about equal to that exerted by the air, and the can would have been crumpled in a like manner. Or weight- ed down in thirty-five feet of water the START TO PLAY pressure would have been the same. A few simple figures and one finds that DA II.tVF 1) t' -S OF RE tL FLAN ! VERY FIRST the can was submitted to nearly eight tons LEARN THE WONDERS OF CHEMISTRY Even if you can't read a note of music right now, of pressure, more than one wheel of a huge Anybody can master the science of chemistry with you play a simple melody on the very day you get run CHEMCRAFT. Work hundreds of amazing and your Deagan Xylorimba. Free easy lessons show motor truck would exert if it were to useful chemical experiments: make soap, ink and you how. Soon you are amazing friends and relatives. over it. In the drawing, the cream can is dyes; test foods, water and soil: produce startling happy evenings of joy; parties; changes and perform wonderful tricks of chemi- Then a new life begins-long, five feet of cal magic. and best popularity; radio engagements-and the same chance to shown standing on end, with CHEMCRAFT is the original Ralph Smith, Chicago-"Played chemical set: bas more chemicals and experi- make $5 to $25 a night as solid iron resting on the upturned base. If ments. Get fun begins' 20 minutes at wedding; received $20." Or the Hellmann CHEMC'RAFr-then your family, Reading, Pa.,-"Made $300 in 5.weeks, spare time." a like amount could be made to force in Seven Dandy Outfits to Choose From: No. 1-$1.00 No. 3-$3.50 No. 8- $5.00 FIVE DAYS' FREE TRIAL-Our big FREE_ book from the sides, we would then have a very No. 2-52.25 No. 12-S12.0ä tells all about this fascinating instrument -the 5-day free 5-$5.00 No. easy payment plan. Send fine parallel to that made by the weight of Laboratory Work Bench $35.00 trial offer-the free lessons-the SOLD WHEREVER in the coupon today-the booklet will be mailed promptly the air. It is this play of air pressure, both GOOD TOYS ARE FOUND without cost or obligation. Try Chemistry for 25c. Free Magazine for Boys above and below the normal of fifteen Get CHEMCH AFTJun- Cl1EMCRAFT Chemist r ior, the set for boys who Club Magazine, full of fine MAIL COUPON TODAY pounds to the square inch, which makes want to see if chemistry ideas, stories, chemical interests them. Sent 1568, 1770 Bedeau Ave.. Chicago high -altitude flying and deep-sea diving so post- stunts and information. J. C. Deagan, Inc., Dept. paid for only 25 cents. Write for your free cops' Send me, without obligation, full details of Free Trial offer dangerous. Order it today! at once. and easy -payment plan on the Deagan Xylorimba. THE PORTER CHEMICAL COMPANY 105 Summit Ave., Hagerstown, Md. Name Address Entertaining with Hypnosis (Continued front page 593) .;Je U.S. By KENA MURAY Government 13Ujldta.. -1. Job is a Good Job ; suggestion that he is falling backward. Real Model The quickest method of accomplishing this is to have the spectator stand erect, $1260 to $3400 f feet together and hands at the sides. In- AUTOMOBILE a This is a real model motor car in every way; with year struct him to make the body rigid, especially a real three -speed forward and reverse gear shift, the knees downward. Close his eyes, and friction clutch, differential, steering mechanism. STEADY WORK internal -expanding brakes, etc. You can build it clearly suggest that you are placing your with your own hands. PAID hand on the back of his neck and that when yourself VACATION Or, if you prefer, you can make a scale model of a it is slowly removed, he will feel himself High -Speed Ship Coaler that will actually load coal. drawn back by an irresistible power and or of a tri -motored mail AIRPLANE that works. MEN-WOMEN that he will fall backward into your arms. We will send you an easily understood instruction 18 to 55 booklet for any one of these models you prefer, free. Before the hand is slowly removed, you These booklets usually cost IOc. each. If you want 20c. All you have to do is to send VALUABLE should suggest continually, that the subject all three, send us your name and address and that of three of our COUPON is falling backward, backward, backward; friends, telling us which booklet you prefer. This when the hand is withdrawn, the subject will is a wonderful chance. Act now! MaU Today SURE slowly fall backwards, to be caught in your MECCANO COMPANY, INC. arms before he reaches the floor. Again DIV. J -I ELIZABETH, N. J, note that spectator is not asleep, but realizes everything that is happening. it (11111 THIS OFFER WORTH 1Ofi s Franklin Institute, Dept. J182, p Rochester, N. Y. SPECTATOR CANNOT UNCLASP HIS HANDS I Rush to me, FREE OF CHARGE, list of U.S. Govern- ment lobs now obtainable. Send FREE 32 -page book - I telling salaries, duties, hours. etc., with sample coaching. 'HIS experiment is always a laugh pro Tell me how I can get a ix,sitiuu poking one and simple of accomplish- Name SEND FOR NEW RADIO I Address ment. The spectator stands directly before you, and clasps the hands tightly together, BOOK-IT'S FREE! the fingers of one hand lacing with those New hook-ups. This book shows how to make hand. the two hands and short-wave receivers and short-wave adapters. of the other Grasp How to use the new screen grid tube in D. C. WANTED MEN! press them together firmly, especially so and A. C. circuits. How to build power ampli- A chance to start your own where the wrists meet, at the same time fiers, ABC eliminators. Up-to-the-minute business MAKING METAL all new radio TOYS AND NOVELTIES as our positively asserting that his hands are glued information on developments. representative -either full or It's free. Send for copy today. spare time tight together and that, try as hard as he Big demand for Toy Soldiers. Ani- wishes, it will be found impossible to get KARAS ELECTRIC COMPANY mals, 5 and 10 -cent Store Novel- 4049L2 -North Rockwell St., Chicago, Ill. ties. Ash -trays, etc. We cooperate o them to come apart. Say, now, try hard to in selling goods you make, also buy them from you. Small investment get your hands apart-try hard! and see needed to start, and we help you to -- how impossible it is-the snore you try, the Name build up. WE FURNISH COM- fingers re- PLETE OUTFITS and start you tighter they get! Snapping the St. and No in well -paying business. Absolutely no experience and no leases the spectator from this suggestion. special place needed. A chance of a lifetime for a man with small capital. Christmas orders are now being placed, so O The ridiculous movements which the subject City and State you me:METALeCASTV 4049L2 PRODUCTS C!OMPANÿon. goes through in endeavoring to free his Dept. E 16% Boston Road New York City hands is always a source of much laughter. AUTOMATIC MOVEMENTS Add $3000 income BY the above is meant that a suggestion Without knocking at back doors, canvassing, or Radio is given for certain movements to be soliciting you can add $3,000 a year to your in- CataIO performed continuously. Commence with the come by taking care of deliveries to stores, check- EREEWholesale ing up on sales and making collections for NEV- Set Builders -Dealers! Save Money! spectator standing erect, eyes on his two ERUN, the new discovery, which prevents runs Send for the most complete book of nationally known forefingers which should be pointed so that and snags and triples the wear of silk hosiery. It l'arts, Kits Cabinets, Consoles, Speakers, Power Units, is the BIGGEST money maker because it SAVES seta etc. All at lowest wholesale ppriees. Quick service they tauch at the tips in front of the body. every woman at least $100 on her silk hosiery and on all your needs. Write now, it is FREE- Instruct subject to revolve each finger around undies. No personal selling. No experience but in- SE'TBUILDERS SUPPLY CO. the other, assisting with your own hands telligence and reliability required. I want men Dept. 17.2 Romberg Bldg. Madison and Market Sts. CHICAGO. ILL and women able to develop Into independent execu- if he does not grasp your meaning instantly. tives. Write immediately. Territories going fast. QUINCY CO., Quincy Bldg., Dept. 854 CHICAGO I'l a .cad; 3oft saw it in SCIL'NCE and INVENTION

www.americanradiohistory.com (Science and Invention for November, 1928

Say Notice, your fingers are moving faster! faster! faster and faster! The faster they go, the faster they go! It is impossible to Coming to stop them, and they are revolving faster all the time! A snapping of the fingers is again NEW YORK necessary to bring the subject away from this train of thought, when he will he normal as before. Endless continuous movements can be devised, depending on the orginality rT"T T T T - of the performer. STIFFENING SPECTATOR'S ARM OR LEG IN this experiment the spectator should be Learn sitting. Gaze into his eyes to keep his attention on what you say, and with the right To EARN hand seize an arm or leg and state clearly $2,000,000 is that notice that your arm getting stiff, it is like a board, that you cannot move it $60o- to $2000 no matter how hard you try. At the same Week how the time, draw the left hand over the arm to a emphasize the meaning. The subject will go go through many contortions in order to move Hotel McAlpin the stiff member, but it remains in the rigid condition until you release him by snapping is spending it. the fingers and calling (Wright. TRICKS OF THE HYPNOTISTS PERFORMERS who professionally use hypnotism for entertainment, and use and .An improvement program understand the eight or more different sleep and waking stages, use the name Hypno- In 12 that will make the McAlpin a tism, from the Greek, meaning to sleep. As NEW Hotel-inside and out in every line of endeavor, however, there are Weeks at Luxurious NEW carpets, dra- self-styled hypnotists who apparently know nothing about the genuine science of psy- peries and furniture throughout chology, and rather prefer to simulate hypno- -bright, cheerful, interior dec- of trained subjects, COYNE tism by the employment spacious, IMMACULATE who are known as plants. Many times the Get in the field that offers you the big pay-Be an oration - Electrical Expert. Coyne Is not a Correspondence modern tiled School. Everything is practical. You work on actual rooms, all with electrical machinery. You do actual work on our electric, self- huge outlay of electrical apparatus- eter}thing baths-high-speed, from doorbells to power plants-here you learn to a NEW earn S60 to 5200 a week. A Coyne trained man can leveling elevators-and take his place anywhere in the electrical world. type of courteous, efficient hotel Have you become a "HOME Learn in ( 'hicaco, the Electrical Center of theworld. enthuses the most You Don't Need Advanced Educa- service that tion or Experience You don't need a high MOVIE" fan yet? school education or pre- critical guests. vious experience at Coyne. My training is prac- We invite you to visit the Turn to page 608 tical and easy to understand. NEW Radio and Auto Course Included McAlpin and inspect the Right now I am including a course in Radio. Also a which are complete course In Auto, Truck and Tractor rooms - several of Electricity and Storage Batteries. already completed. Earn While You Learn -We help many non -genuine hypnotist is known to hire sub- students to secure All improvements are being part time jobs to earn a good part of their living jects locally at a dollar or so a head, before expenses while training and assist then to a big effected without the slightest in- the performance, with the understanding pay job on graduation. of service. that they are to do exactly as the performer Send Coupon NOW ! terruption Don't delay a minute-send that coupon right instructs them. now for my big free catalog and full particulars Fake hypnotists are to be pitied, rather of special offer No obligation on your part FRANK A. DUGGAN at all. ACT NOW! than criticized, for their lack of knowledge ; President and Managing Director Coyne Electrical School yet, the "tricks of the trade" which they St. C. LEWIS, President employ will prove interesting to the reader. too S. Paulina St. Dept. 18-83 Chicago, HOTEL THE WINDOW SLEEPING TEST ill. genuinehypnotism, this is accomplished I'by suggestion. For advertising purposes, Get mÿ (NI M`ALPIN the subject is placed in the lethargic stage of ' SPECIAL sleep, and lies in a store window for twenty - Big Free ONE BLOCK from PENNSYLVANIA STATION f our hours, to be later awakened on the OFFER stage of the theatre. Book How it is faked. The paid subject under- NOW B'WAY at 34th ST. goes a training consisting of lying perfectly still at all times. On the day of the "window sleep" he eats barely nothing, and just before $1000 Profit going into the window to fake sleep, con- \, sumes a large dinner of fried onions which for Agents! are the most common, as inducive to easy sleep. Of course, the credit goes to the i .!1jYear subject, who is able to lie for hours with- 1 out smiling or moving a muscle, the result r of rigorous training in this work.

Everyone is ever of a for themnel i. wonderingThinking not ona. ly what to selectbut bow THE CATALEPTIC TEST to conveniently pay for it. Show them our plan of easy payments. Show bow easy Ode to have a beautifl iamond ring.wetch. silver- ue, etc. d Irve twelve months toa pay. Oar agente earn from WE are all familiar with the test wherein weryboeineeafoéyoúraelfandearryth etttocdkforyyoú Yoemakeno the subject is made rigid, like a board, io eatmeet.Yoenerelytakeordenaodearnvennberaleommineion. and suspended between two chairs, the feet Name...... ;fend for FREE adfli TODAY on the back of one and the head on the Write for complete free outfit, which contains catalog in olora. Address...... order blank and gull instructions. We send by return mail every- back of the other. thing to start without ST joERLING DIAMOND AEN CD. Inc. With rigid training and practice, prac- 1540 Broadview. Dept. 522S Clew York, N.Y. City..... tically anyone can duplicate this feat with- . Of course, by out the aid of hypnotism. lat employing hypnotism, the genuine subject e...... BE A DETECTIVE is enabled to undergo such tests as allowing Earn Big Money. Work home or travel. Make secret In- vestigations. Experience unnecessary. Write Dept. S. A. several heavy people to walk on him while plerican Detective System, 2190 Broadway, N. Y. he is suspended between the two chairs, Please say loti saw it in SCIENCE. and 1.V V13_VTION

www.americanradiohistory.com 662 Science and Invention or November, 1928

or of having rocks broken on his stomach YOUR CHANCE while in this condition. Both can also be done without this aid because some "plants" $5,000 to $12,000 are even able to support a human being on their stomachs while between two chairs, a Year without losing any of their rigidity. A straight forward o r portunity - THE BLOOD TEST No magic or "get - AGENUINE subject, who has been genu- rich -quick" scheme inely put to sleep a number of times, about it. The skill can be made through suggestion to contract is built in the the muscles of either arm so that the muscle Clarke. pressure causes all of the blood to leave the arm, leaving it perfectly chalk white, and No schooling or allowing the blood to return to the arm at tuition the will of the hypnotist. necessary Like the other genuine experiments, this AVIATION -we show is also imitated. The non -genuine subjects EVERYBODY'S AVIATION you how. sits sideways on a chair, with an arm over GUIDE is the back of the chair. He clenches the fist a complete discourse $300.00 and contracts the muscles of the arm as on practical aviation, by MAJOR total investment with part - time much as possible to drive the blood black VICTOR W. PAGE, one of the payments if you can qualify for into the body, and at the same time presses leading men in the field. Unlike this opportunity. the inner side of the arm against the chair most books of back, causing the blood artery there to be instruction, "POINTING THE WAY" closed by pressure. When the fist is opened, EVERYBODY'S AVIATION gives the FACTS - illustrates by it is naturally white and bloodless, and when GUIDE is written in a unique photographs the work-and contains the pressure is released from the artery the question and answer fashion, the written testimony of men who blood naturally instantly rushes back, color- which makes the subject far easier are making money ing the previously white arm a deep rose. to big as Clarke This is a simple test than can be accom- study and a great deal more Flor-Kraftsmen. NOW, while it's plished by anyone, although of course it attractive as an instruction on your mind, cannot compare with the effect obtained course. SEND THE COUPON TODAY when genuine suggestion or hypnotism are employed. This book was recently published and Ì is absolutely up-to-date in every way. CLARKE SANDING MACHINE CO. THE PAIN TEST Dept. W-11, 3834 Cortland St. ' It has had very favorable criticism Chicago, Illinois IT is well known that under hypnosis, any throughout country -wide aviation cir- Please send without obligation to me illus- cles and has been highly recommended trated copy of "Pointing the Way to Greater part of the body can he made immune Profits." from pain. Hypnosis has been used fre- by all those in a position to pass judgment. Name quently for minor and sometimes major operations in hospitals without the use of We list here the contents in order that Addrecc ether or chloroform, as it leaves no bad you may see for yourself how com- City State after effects and the rapidness of recovery pletely the field of Aviation is covered. is remarkable. In faking this, countless small tricks and Contents: subterfuges are used. Sometimes a long Early Aeronautic History-First Flying needle is prepared by cutting it in two in Machines-The Atmosphere the centre and soldering to the separated Forms of Aircraft-Airplanes and Air- ends a piece of flesh -colored wire that half ships Lighter -Than -Air Craft-Balloons and encircles the arm, and gives the impression Dirigibles that the needle goes directly through the How An Airplane Flies-Elementary flesh. Aerodynamics - Airplane Parts and Their Functions Some, like the fakirs of India, make no Fuselage Forms and Landing Gears attempt Wing Arrangement and Construction of fakery, but have a spectator lift Power Requirements, Engine Types and THE BARAWIK CO. has, all these years, a portion of been famous for its variety of radio supplies. the skin of the arm through Engine Location which it offers at money -saving prices. New- which they plunge an unprepared needle. Aircraft Propellers, Design and Applica- est dynamic speakers, B' eliminators, socket This is easily duplicated. All that is re- tion power equipment, A -C harness, fine cabinets Airplane Equilibrium and Control and furniture, amplifiers, latest amateur quired is a needle that has been sterilized Official World and American Air Records equipment, tubes, batteries; in fact, anything with an antiseptic, and plenty of nerve. you can ask for is here, ready to ship, at a Have the spectator lift a portion of the skin saving in price. Quality merchandise, selected of goods by reliable makers - just what you the arm between two fingers, and boldly want -at big discounts. plunge the needle through this lifted part of the skin. The skin is tough and con- Your Savings areTremendous siderable pressure is required, but it will Ask any of the quarter million Barawik customers why they trade here, and they'll tell you that, be found that there is practically no pain quality coital our prices can't be beat. whatsoever as the needle passes through the That's something to think about! Quality comes first-new, fresh, good reliable merchan- skin and not through the flesh of the arm. Price $2.00 dise, but the price always means a tremendous saving, nevertheless. \\'hen the needle is withdrawn the wound Get our catalog and prove this does not bleed, and leaves only a slightly to yourself. Don't spend a nickel until you see our offer- smarting sensation. There is no danger ings first. from blood poisoning if a bright new needle You steed this great radio that has been dipped in sterilizing liquid bargain book as never before - Mail the coupon is used. Alcohol is a favorite antiseptic. Over 248 pages now - TODAY. Beautiful red cloth binding-Title in gold DANGEROUS METHODS Replete with illustrations BARAWIK CO. CHICAGO", 1 THERE is no danger connected with the WRITE DIRECT TO t Mall This Coupon for FREE B.raaln Book. use of hypnotism when one understands it thoroughly, N.,n. but the reader must be warned Consrad Company, Inc. never to experiment with the "instantaneous 230 Fifth Ave., New York, N. Y. Addr.st hypnotic" method sometimes seen, and which is positively injurious. I refer to the prac- CONSRAD COMPANY, lac. tice of nerve and muscle control, which is 230 Fifth Ave.. New York, N. Y. really not hypnotism at all, but a method Gentlemen: Kindly send me one copy of your book, EVERYBODY'S AVIATION GUIDE. Mailing Lists of paralyzing the nerves and stopping the Enclosed find $2.00. Will help you increase salet blood supply to the brain, which of course Rend for FREE stale givings couples rices on of ) produces a temporary sleep, which is in Name enofyour beet prospective eo,tom- edselBedsala -Nctlonal, State end Local--ledlvid- reality a sort of paralysis. Professions, Business Co carne. ne Guaranteed 7i One method consists in placing the arms Address /0 b refund of 5 each around the chest of the subject and squeez- ing, while the subject maintains a lungful City State of breath. The other is the pressure on the Please say nu saw it in .SCIENCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928 663

nerve centers connecting with the brain, usu- SKINDERVIKEN ally reached by pressing on the nerves un- derneath the chin, in a line with the eyes. Units Either of these practices are liable to cause Transmitter permanent injury or paralysis; not so, however, with any experiments wherein the re- 95C sults are obtained solely by suggestions made by the performer. It is frequently supposed that a person must be weak minded to become a hypnotic your present future subject. Such is decidedly not the case. Neurotics, idiots and imbeciles are the most with the one that difficult to place in a trance because they will not or cannot concentrate. Don't try the effects on giddy people because you will Hinton offers you be largely unsuccessful.

Inventors Ease Mothers' Have hundreds of uses. Every amateur should have two or three of these amplifiers in his laboratory. Cares A FEW USES FOR THESE UNITS Continued from page 597) -LAUD SPEAKER a'PF,am.,, +., A' RETRANSMISSION- o, «ct EVCN RFWARD$ - {Ili / ELECTRIC BOTTLE WARMER ' JWIATIOiV MALL bottle warmer that is electric- Asally operated has been invented. A little f, water is put in this and the nursing bottle 1 s oN is placed in the water. Then the current is on. When has boiled e turned the water e.,,co. -l. away, the milk is heated sufficiently for baby j ific and the electricity is automatically shut off. tüiil . .w baby walker, stroller, four- : 11.11"1"1"rilligt) o,.c A combination IS THE work you are do- ro ac.Psa acccrvco wheel coaster car and vehicle pushed by ing intèreiting? Does it Si.iowc: -FMPLmcR- you $40, $75, $100 LEAK- with the pay $60, GaID pedals has been invented. It grows a week or more? Have you a chance to becomeTa ..,.. child. It was made tò fit the small baby responsible executive or "your öiVn BOSS"? If not, RADIO AMPLIFIER-,iAMPLI and to provide suitable adjustments to main- it's time you were getting into Aviation-today's fastest -growing industry with tomorrow's biggest future. y , tain correct fit as the child grows older You simply can't realize how this great, new field is and bigger. growing. Manufacturing companies, transport lines, There is further a new combination of airports, service and sales organizations are developing 1:1. so fast that it's almost a physical impossibility to get -ONE STAGE high chair, toilet seat, baby swing and auto intelligent, energetic, "air -minded" men to fill the AMPLIi'ICATION- seat into one, compact portable unit which important positions. In Aviation, the jobs are in lina -'r- TO n..... suggested attention. Hung over the back for the men-in other fields, the men are in line . of a chair, it makes a practical high chair for the jobs. va;un 'Vr `l';ll u«s for the baby. The child is supported by on the Ground a tightly stretched cloth back and the chair z: ..L1 1 111 or in the Air a1 is protected from scratches by presence of Big Money Lu.P *MON Nr,or, a rubber covered hanger and rubber guards. Don't think you have to Ily to be a big SUCK RS in Aviation' Good pilots draw subètantial-salaries-sure! But do good TO 400IXn,O Thus a mother can have the baby in her . eaPa.G. mechanics, electricians, radio men, salesmen. instructors -TAUhNG LIGHT -DCTCCTOa sight in a high chair wherever she happens and many others. Aviation's best jobs aren't all up in the air-not by a long shot. For every plane that 'files, there -CODE PRACTICING DEVICE- ..e to be working. As a toilet seat, it can be net « ,o. muetbe-ten-to-forty, highly paid, carefully trained specialists o used in two ways. By. placing it over a large on the ground. Forgetthat Aviation.was once considered a ,' game" Forget that just a short Lime ago it was Still lilla _:, toilet where spacial rubber studs hold it experimental stages. Instead realize that today It 113 othe in place, the child is held securely in the most efficient method of transportation the. business world ° -_ 1. oe.G . has ever known-and realize that within the next few years I.acT 1, seat. By hanging it from a chair, with a it is going to make thousands wealthy and put countless . v',. chamber beneath, the baby has a comfort- others on ' easy street" for life. `" 4..wn...... "." _anLDy' PHONOFMPLIrIW- able seat and can be watched by the mother who is nor compelled, though, to leave other Get Started Quick 12 PAGE INSTRUCTION BOOKLET duties. containing suggesticns and diagrams for innumerable. Home uses, furnished with each unit. A swing attachment converts this unit -at into a baby swing, having springs that give Under the guidance of one of Aviation's outstanding figures WE PAY $ 5.00 IN CASH it a gentle jumper motion that the baby Lieut. Walter Hinton, pilot of for every new use developed for unit enjoys. Placed in the angle of the auto the famous'ltans-Atlantic NC-4, this and crack flying instructor for and accepted and published by us. seat, it fits into the upholstery by rubber the Navy during the War-you studs which hold it securely. There are can now get your" groundwork" in Aviation right at home. In P. G. MICROPHONE TRANSFORMER no straps or hooks. his remarkable, up-to-the-min- A Modulation Trans- ute fully -illustrated course- Walter Hinton which he backs with his own former specially de- SUN SUITS personal instruction-you get One of the Navy's crack signed for use with quickly, easily, Inexpensively flying Instructors during-the the Skinderviken Trans- SO -CALLED sun suits, very light clothing just the very training Aviation's war, pilot of the Ne -4, first mitter Unit. Has many big operators seek in the men piane to fly the Atlantic, other uses. Primary that gives plenty of chance for the health - they employ. Hinton's book, first Aviator to pilota plane giving rays of the sun to reach the skin, "Rich Rewards. in Aviation." from North to South resistance, was written for YOU. Don't America, first pilot to fly'to ohm; ncesec- are being introduced in increasingly wide turn this page until you've the wild regions of the ondary, 55 told him where to send it. Upper Amazon - that's ohms. area. The U. S. Bureau of Home Econom- Hinton, the man who Is has now ready to give you the ics of the Department of Agriculture cream of his many years FOR SALE AT LEADING DEALERS recently designed several kinds of clothing AVIATION INSTITUTE and thousands of miles of OF S. A e riene. And he brings Or Order Direct, Using Coupon Below for kiddies and even little babies soon U. this foundation -building, show what can be done in suits that promote 1115 Connecticut Ave. money - making training right to your home.' His SEND NO MONEY health. Washington, D.C. FREE book tells you how. When the postman delivers your order you pay him for For children who cannot get out-of-doors whatever you have ordered, plus a few cents postage. and into the, warm sun and for those who do not live where there is warm weather PRESS GUILD, INC. S & I-11-28 16-18-D-East 30th St., New York, N. Y. much of the twelve months, scientists have Please mall me at onoe as many of the following items invented sun -lamps giving ultra-violet rays Lieut. Walter Hinton, 4-L as I have indicated. help Aviation Institute of U. S. A., ....Skinderviken Transmitter Units at 95c. for 1; $1.75 from quartz mercury lamps to combat 1115 Connecticut Ave., Washington, U. C. for 2; 52.50 for 3; $3.20 for 4. rickets and other enemies of the baby and Send me your FREE book, "Rich Rewards in P. G. Microphone Transformers at $2. Aviation," telling how you can give me my "ground When delivered I will pay the postman the cost of the small child. The results of this invention work" right at home. items specified plus postage. are seen in strong teeth and in good health of the babies using the treatment. Name Name - To flood the baby's room with health Street 4 c4 Address giving sun -rays there has been placed on the market a so-called vita glass that permits City =t:It,- _ - rays to pass. me» two Mt Mr.Iflf dtty - State the health -giving w Please says you saw it in SCIENCE and INVENTION

www.americanradiohistory.com (4)4 Science and Invention for November, 1928

Over in London someone invented a motor baby carriage recently. Photographs sent back to this country showed a nurse riding Orders - Inquiries along on the driver's seat and in the carriage, that looks like any other baby cab, Make $5,000 are two babes. This vehicle is said to have Can be been designed to go no faster than two ,cured to $15,000 a Year Of e sting miles per hour. In London, too, there is a baby cab that by BatteryService Station is so made it should not tip over at a street Tremendous profits easy for crossing even though apparently thrown 1AI L you to get charging batteries. considerably out of balance. To promote Customers come right to your door. No soliciting-no hard safety for the baby, this cab was made work. Every time you connect securely fastened to the frame by springs a battery you make 90c clear instead of straps and so balanced that it profit. My Service Station is unlikely to tip where an ordinary carriage Charger is years ahead of or- POLK' PREFERENCE BOOK dinary chargers. You can get might. all the business in your town. A Chicago bachelor invented a baby car- and Mailing List Catalog Start in your garage, basement, or rent a store. riage that can be rocked gently by an elec- Gives counts and prices on over 8.000 tric motor so that the nurse or the mother different lines of business. No matter Down Starts You. what your business, In this book you $5.00 may attend to other matters while the baby will find the number of your prospective customers I've a FREE BOOK explain- is resting in the cab. It gives a rhythmic listed. prepared Valuable information is also given as to ing how to get into this big pay field. soothing motion to the cab, though not ac- how you can use the mails to secure First week's profit pays for all equipment. companied by a lullaby or so. The inventor orders and Inquiries for your products I explain everything-start you in a busi- is James Vicek of Chicago. or services. ness of your own and put you on the way Write for Your FREE Copy to Big Money. This book is yours FREE. R. L. POLK & CO., Detroit, Mich. copy Don't MISCELLANEOUS Send for your today. Largest Clto Directory coupon and mail Publishers In the World delay. Fill in ASPECIALLY designed spoon that the Mailing List Compilers-Business Statistics at once. baby can easily put in the mouth with- Producers of Direct Mail Advertisine out the difficulty usually encountered in managing one of the long -handled adult size spoons has been invented. C. F. HOLMES. CHIEF ENGINEER I INDEPENDENT ELECTRIC WORKS I For the family where there is only one DEPT. Si 1 baby, a clever inventor has made a teter- 5116 RAVENSWOOD Avg. . CHICAGO, ILL. I toter that one can operate all alone. This has PARKS Send me your FREE BOOK "Big Profits" j a spring to take the place of the second per- W94PWORKING MACH,NLS IName son on the teter-toter. Cabinet Little fenced -in play -yards of wooden con- Shop Add City struction are on the market for babies who need to get out on the porch or lawn to Special play while the mother attends to other du- No. 10 -4.7111111 ties without cause to be concerned for the safety of the baby. Some of these have sets of beads or blocks on the sides to help the $290 High School baby learn to count or to spell or to recognize pictures. with Motor Course in ruii ought ID have this handy Parks in your shop. PORTABLE POOL Compact, completemachine 2 Years designed Ilke a big produc- APUDDLE pool, beach tion outfit at one-fifth the cost. Fits In a comer of your This simplified. complete High School duck a portable basement. Does any kind of cabinet and joinery work. Course-speciallyprepared for home study that can be placed on the lawn or on Write for circular by leading professors-meets all require. the floor, is made of canvas and in it the THE PARKS WOODWORKING MACHINE CO. ments for entrance to college. business, and 1553 Knowlton Street. Cincinnati. Ohio leading professions. baby can splash about in the water, which Canadian Factory: 205 Notre Dame East, Montreal Other Over 200 noted Engineer,. Bus. can be made of the depth that the mother e rsesIneesMen, and Educators helped prepare the special instruction feels is safe. Thus the baby can move Çwhich you need for succesa. No matter what around in cool water on the lawn, with a your inclinations may be, you can't hope BOYS! BOYS! BOYS! to succeed without specialized training. Let protecting canvas on all sides to keep the nagts. you the practical training you need. infant from crawling away. s'slz ï"FIROW American School A portable seat that fits any toilet and Dresel Ane. 8. 58th Street YOUR Dept.H-8294 Chicago which can be folded and carried in a bag or other small space has been invented for VOICE Money Back When You Finish If Not Satisfied oto a trunk under the bed or comfort of the baby when visiting away anywhere. Lots fooling the u er American school, Dept H-82940rexel Ave. and 58th SL, Chicago from home. Friends Send me full information on the subject checked and bow you will help me win success In that line. A toilet seat that can be carried any- Architect Electrical Engineer where has been designed especially for use THE VENTRILO, s little instrument, fits in the mouth out Building Contractor General Education on heavy of sight, used motor trips. This has a paper with above for Bird Calla, etc. Anyone can use IL Automobile Engineer Lawyer NEVER FAILS. Civil Engineer Mach. Shop Practice insert that is discarded after use and that Also a 82 PAGE BOOK which gives foil isetrncttoaa on Ventrllognlem. Formula for Structural Engineer MechanicalEngineeer thus promotes health for the baby. Secret Writing [Invtsihle Ink], 12 Money Making Secrets Business Manager ....Steam Engineer Several kinds of guards worn on the cod 10 BIG TRICKS ail for A. & Auditor Sanitary & Heating ON MAGIC IO¢ .. C. P. hands to prevent sucking of thumbs have ROY. NOV. CO., Dept. 625 Norwalk, Conn. Bookkeeper Surveyor&Mapping LARGEST and OLDEST Mati Order Honeste Connecticut .Draftsman & Designer High Scheel Graduate been invented recently. This habit should he prevented, authorities say, because it Name favors mouth breathing and development of Address adenoid growths and causes deformities of the teeth and jaw. life's newy A baby bottle sterilizer, recently invented. AmazingSecrets! book..SafsC 1 ' is placed in a saucepan containing a little l o insight fro 1tÁ. eh eiderOie advice to newly married. Explain. Anatomy of water. Live steam and boiling water cir- ts. organs, Impotence, laws of Sex - Liprodenfe, mistakes to avoid, disease., erego re. culate within the bottle. The principle is etc. Contains 9 startling sections: 1 -Science - Eugenic.. LLove, 28--Mae . -C - the same in a general way as that which birth, a -Fare2- ng Hygiene.Disease. and Dlsbere, 8-H hee d- Hygiene. -Story of Life, le sii, toa the coffee percolator employs. 7 pages. Examine There are now nursing bottles of glass o risk. Mulled na ptnwrrrrr. 500 TRICKS -10C. that will stand extremes of cold and heat Send No Money just as certain ovenware does. These do Write for your copy today. Don't send a BE POPULAR-LEARN TO ENTERTAIN Ant. Pa yo.tmn only $1.98, plus poetege, Amaze and mystify your friends. Earn Money not roll, either, are easy to clean, and easy ne meiosi. ilote, refunded If not aatisfaetorr. at Clubs and Parties. It's easy. No skill FRANKLIN PUBLISHING CO. required. Our copyrighted book, "Fun- for the baby to hold. They remind of ,pt. r,10í, 800 N. Clark St., Chicago, Ill. Magic-Mystery tens how and explains the bachelor inventor who thought he had many tricks you can do. Also catalogs over 500 Mystifying Tricks Illusions Jokes- a marvelous idea for a baby bottle that Puzzles-Books-European- Novelties,- at Re- duced Prices. New 1928 Edition, profusely would not break-a nursing bottle of alumi- illustrated.'sent postpaid, only 10e. num! And his friend, who was, laughed Foreign Work! Like to Travel- Does Romantic, W eaithy South Amer- LYLE DOUGLAS, Station A-3, DALLAS, TEX. kindly and said : "But you see you have to be ica cell you? Unusual opportunities for young American employers. are d expenses furnished. PRICES able to see through the bottle to see if the ¡'A Y. Write for Free Lies. PROMPT SERVICE-LOW SOUT14600 AMERICAN SERVICEBUREAU little codger is really drinking the milk." Alm. Detroit. M ehlgae Please .say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com 6ü5 Science and Invention for November, 1928

Hints for the Mechanic "rst prize of $10.00 will be paid every month for the best idea submitted. Other ideas published will be paid for at space rates. ; '.e

FIRST PRIZE-$10.00 SLIDING CHUCK Aviation New York's Brings Quick Newest Hotel Success TO young men of daring no other znje field of work offers such a fascina- tion, such high pay, nor such opportunities for quick success as the field of Aviation. As yet, aviation is practically ßíccabítip in its infancy. But now is the time to get in. 227 West 45th Street Amazing Opportunities At B.'way-New York in Airplane Industries In the automobile industry and in the moving picture business hundreds of men got rich by getting in at the start. They made their succese before others woke up. Today, these lines offer no greater opportunities than a hundred and one others. BUT AVIATION IS NEW. Get in while . the opportunities are big. 'All over the country there will be a clamor for trained men. It will not be a question of pay but of getting capable men. Adjacent to Every The above illustration gives the details for the construction of a sliding chuck which is Easy to Get Into Aviation Activity adaptable to most lathes. With slots arranged as shown, it can be slid to any desired posi- By this Home Study Method tion and held in place by means of the thumb The study of aviation is almost as fascinating nuts. B designates the slots and a section as the actual work. Every lesson is full of in- 600 Bright Sunlit Rooms through the line AA shows how they are fash- terest. That is why it is easy to learn -aviation. ioned. A raised portion 1/16 -inch high paral- You do not have to make yourself study-it is Each with Bath, Elec- lels the slot on both sides. like reading an interesting book that tells you things you have always wanted to know. Only , tric Fan, Ice Water one hour each evening will give you the basic ' "HANDY RULE" training in a surprisingly short time. One student, S. F. McNaughton, Chicago, says:. "Your lessons are like and what Single Room & Bath, $3.00 is'a oma ce, reading,the student gets Double Room & Bath, $4.50 PICK ing. One nunderstand-f reading them" James YOUR JOB! Powers, Pa., another Exceptional Restaurant student, says, "I am in- Flying deed surprised that and Luncheonette such a valuable course Airplane Instructor can be had from such Airplane Engineer practical men for so Wire at Our Expense Airplane Repairman little cost." ' Airplane Assembler for Reservations Airplane Personal Instruc- Mechanician tion by Experi- Airplane Inspector enced Men O The small rule found on the index page in Airplane Builder Men who have had ac- this magazine each month can be applied to Airplane Salesman tual experience give celluloid. Wet and rub until layer of paper Exhibition Manager you personal attention. rolls off, allow to dry and paint on face with They select the lessons F. D. SOFIELD thin varnish. Place this face down on a Airplane Contractor lectures, blueprints and piece of celluloid, allow to dry and trim Airplane Motor bulletins. They tell you Managing Director edges.-Norvell C. Wood. Expert things that are essen- Airplane Designer tial in everyday practice. Each lesson ii BENCH HOOK easy to read and un, derstand. Get Big FREE Book-Now Send coupon below for New Book, just out, Opportunities in the Airplane Industry. It is interesting and instructive. It will show you WHOLESALE many things you never knew before about aviation. We have but a limited supply of PRICES these books-send the coupon before they are Everythiing in radio kits, parts, all gone. accessories, sets. Improved de- American School of Aviation signs and styles. Big selection at 3601 Michigan Ave., Dept. 1428 worthwhile saving. Immediate service; personal attention. Send Chicago, Ill. for complete, illustrated Cata- log "D -L" Wholsale Prices. l American School of Aviation 3601 Michigan Ave., Dept. 1428 Chicago, Ill.

t I Without obligation, send me your Free Allied Radio Book, Opportunities in the Airplane Industry, CORP RATION The usefulness of a bench hook can be in- Also information about your Home Study 711 W. LAYE STREET, CHICAGO creased by sinking a rule along on edge and 1 Course in Practical Aviation. one side. These should be level with the top. Three cuts made in the end board fur- Name Age BE AN OIL EXPERT ! nish a very useful miter board. The above Trained men needed! Geologists,\ Drillers, Refiners drawing shows how this can be accomplished. Street (Chemists and StiL Men), Oil Salesmen, earn 2 to 10 times more than othe. fields. Write today! FREE Booklet! All the screw heads should be countersunk. in The bench hook thus serves a triple Stale Petroleum Engineering - University, Dept. 271, Fort purpose. City Wayne, Ind. -Herbert Erickson. Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com 666 Science and Invention for November, 1928

ransmission of Photo's by Radio HOME MOVIES ANSMISSION OF PHOTOGRAPHS the electron flo-w constitutes a dis- (Continued front page 639) BY RADIO - Various methods have charged circuit, so that the grid be- been devised and are now in use for comes less negative. The first ampli- i the transmission of photographs by fying tube is a direct current potential radio. Among these may be mentioned amplifier, and is resistance ceapled. matic the systems of Belin (q.v.), Baird, and The grid and plate connections of the film and color filters providing a re- Jenkins. The principles underlying -amplifier are connected across a con- production of scenic beauty that is en- the Jenkins system are explained denser which becomes discharged with trancing. under the heading of Television. the fall in the grid to plate resistance There are many underwater scenes show- Using the system developed by Capt. of the valve brought about by the grid ing how pearls are gathered and also how R. H. Ranger, photographs were potential fluctuations. A charging cir- the South Sea Islander gathers his meals transmitted by radio from Honolulu cuit is connected to the condenser and from the sea. The native feast is truly to New York, a distance of 5,136 miles. is controlled by a valve, the grid cir- educational, the preparation of the food be- Recently commercial picture trans- cuit of which operates by variations ing shown in detail, utilizing strictly native mission service has been inaugurated of the potential across the condenser. methods of preparation. There is one thing between New York and London using The charging current is fed through about this picture that is both new and novel, the Ranger apparatus. Two distinct the plate circuit of this valve, in which the fade-out at the end. Usually at the end ethods have been applied for analyz- a relay is connected, which working of a photoplay the scene simply fades from ing the picture in the process of trans - through other mechanical relays in view, but in this case-now we are not going to tell you how it is done. We want you to tell us, and to the reader of SCIENCE AND INVENTION who best and most completely describes how this effect was obtained, we will award a prize of a reel of 16mm. film, entitled "Nonsensical News." The contest is open to every reader except professional cameramen or others engaged in, the production of professional pictures. Letters should be addressed to the "Fade-out Con- test" Editor, SCIENCE AND INVENTION, 230 Fifth Avenue, New York City. Letters should be written on one side of the paper only and should not exceed 250 words in length. Entries must reach this office not later than October 25th, 1928 and the award of prizes will be announced in an early number.

A pencil of light traverses the picture which is attached to the glass drums and is analyzed by a slow rotating, action as well as a backwards and forwards movement of the carrier. Radio Movies Demonstrated mission. One arrangement censists of cascades, controls the radio trans- (Continued from paye 623) roducing an image as a non -conduct - mitter. . Wave trains from the trans- deposit upon a metal foil which is mitting. station after detection and versed by a stylus, while the other amplification, .are applied to the pic- of the independent and more powerful plate thod makes use of an opaque image ture recorder. The recording mechan- current. osited upon a transparent film ism, inI order that it may be sensitive Thus the mercury arc lamp goes bright tich is traversed by a beam of light, to ext;éedingly small currents, com- or dim as fast as the current changes, and to light interruptions being recorded prises, a !mall moving coil, in a mag- its light at any instant is in proportion to y a light sensitive cell. The Ranger netic, field created by three electromag- the light that the electric eye sees in the /stem makes use of this latter method. nets. . The coil of wire, in moving in sattte instant. To return the dots of light The image is 1 e I to _ _ , rded the field, as the received fluctuations to their original pattern, another ,ipon a eel revolving disc or scanner is also used which is similar to the transmitting scanner. The use of a mercury arc lamp permits the radio pictures to be thrown upon a ground -glass or screen, the first time this S.Gernsback's has been done with television apparatus. Both these scanning discs turn at exactly Radio the same speed ; the hole in the receiving disc must be exactly in the same relative position as the corresponding hole in the Encyclopedia transmitting disc. In other words, they must A facsimile of a portion of a page from S. be synchronized. Gernsbacks Radio Encyclopedia is reproduced herewith. A glance at the thorough manner in RADIO WAVE USEDDISCSTO which each item is treated cannot tail to instill a SYNCHRONIZE true appreciation of the value of the remarkable book. S. Gernsback's Radio Encyclopedia is From the the first ever published. It is not a dictionary. transmitting equipment, which It covers every possible phase of radio. Every may be located in the broadcasting station, circuit, each piece of apparatus, all the leading there is transmitted a constant frequency characters of the industry, broadcasting, receiving. television, telephoto, everything con- wave of 5,000 cycles. This wave is pro- nected even in the slightest way with the growth duced by a tuning fork, and transmitted over of radio or its kindred sciences, is most authen- a special carrier wave from the broadcasting tically explained There are over 1930 separate definitions. 549 illustrations, a complete cross station. The constant frequency note is re- index, and many other special features. ceived on a special receiver and by means S. Gernsback's Radio Encyclopedia comes in two of special apparatus controls the speed of beautiful bindings, large 9 x 12 in. size. synchronous motors, which drive the scan- Cut here COUPON Cut here ning discs of both transmitting and receiving radio movie equipment. This unique Beautiful Limp Suede Edition (de luxe) $5.00 ecording mechanism of the receiver. TM method of controlling the equipment indi- Keratol-Leather Stiff Binding $2.00 which a moving co cates, in a measure, the extent tc,5which science must go in order to Write your name and address in the margin perfeeisay tele- below, mark which binding you prefer, and applied through its windings, vision, or radio movies. the book will be sent to you C. O. D. plus ates a stylus while travelling It is stated that the regular.' transmission postage. ''ss the surface of the paper. The of motion pictures from KDKA will begin us traverses the paper in perfect shortly ; also that the radio movie reception S. GERNSBACK chrony with the carriage of the apparatus, when produced commercially, 230 FIFTH AVE. NEW YORK, N. Y. nsmitter, the paper being Iifted will be sold through the regular trade con- It% nections. Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com 667 Science and Intention for November, 1928

Wood Turning for the "9111111,""`011111111"1111111I Amateur By H. L. WEATHERBY A few cents a day (Continued froto paye 614) brings you TNCUSANDS CF DC L LtL?S Choose as Your Profession Sponsored by RCA, G -E Electrical and Westinghouse, this radio course qualifies Engineering you for big earnings brilliant future to the young Ileetricit offers The above photograph shows the pad which is man who is about to choose his career. Never be- in French polishing. SUCCESS. fore has there been such wonderful opportunity in used and this great field. Big paying positions in electrical are open the shellac comes in contact work the world over bottle so that is golden to trained men men who the pad. In the same manner apply men-here your B. S. Degree - practical with WIDE-AWAKE ErZIs specialized, a small quantity of alcohol to the pad, fol- opportunity. A few cents a day, real in 3 Years knowledge. Come to the increase School of Engineering of Milwaukee-the largest, lowed by a drop or so of oil which is rubbed ambition to succeed, and you can the best equipped electrical school of its kind in evenly over the pad. your earning power by hundreds of dollars America. Here you are trained in both theory and practice by a faculty of experts. You learn in large, each year-many thousands during your finely equipped labcratories. If you have 14 high WHEN this has been done, and with active business career. school credits or equivalent, you can become an the work in motion, hold the pad Electrical Engineer with a Bachelor of Science de- piece. Gradu- gree in 3 years. If You have not finished high school lightly against the revolving The Radio Institute of America, conducted you can make up the credits you lack in our short ally increase the pressure, but do not at any by RCA and sponsored by General Electric Intensive Junior Electrical Engineering course. time bring enough pressure to bear so that offers you at low cost first and Westinghouse, the work or finish shows burning. The the training you need for success in radio. Practical Electrical Education coat should dry thoroughly before the second Learn by the therough, approved scientific meth is applied. If too much oil is used the finish Nothing so clear, comprehensive and up- ods whieh our twenty-three years of specializing en- not last. If too much shellac is used able us to give you In addition to Electrical Engi- will to-date, nothing so generous in apparatus neering, the following complete courses are given: rings will occur or the work will be sticky furnished has ever before been offered in A.C. and D.C. Armature Winding-Wiring and and hard to manage. When rings do occur Testing-Practical Electricity-Commercial Electrical liberal applica- radio training by any organization. Engineering-Junior Electrical Engineering and Auto- they may be cut off with a motive Electricity, Electrical Refrigeration, and Radio tion of the clear alcohol on the pad. A This is basically the same course that has Sales and Service. slight sprinkling of rotten stone will improve enabled our thousands of graduates to ad- the polish as it is being applied, but too to positions of importance and high EARN WHILE YOU LEARN gloss. vance much of it will cut the remuneration in the respected profession You can earn money to help defray your ex- A French polish is rather difficult to is mastered it of radio. But new and revolutionary penses while learning. Our wonderful co-operative apply, but when the method and plan brings an Electrical Career within the reach of be found the most satisfactory way to changes make the instruction clearer every ambitious man. Our Free Employment De- will faster progress-and the partment secures positions for those students who finish turned articles. No other method easier, permitting wish to earn part of their expenses. In addition the comes up to it in results. One must learn course now embraces television, airplane Department trill hep you get a good position in the the right proportions to use and photoradiograms. Electrical induotry when your training is completed. by experience radio equipment Daily Broadcasting WISN. on the pad, the correct pressure to apply and the number of coats necessary. Care must Furthermore you can study at home-when New Terns Opens NOW be taken to remove all oil from the last you please and as long as you please. Your the finish will dull in a short while. rate of progress is limited only by your - Write for FREE CATALOG coat or With reference to other finishes ; the own ability. Mail the coupon today for our big new illustrated author has always found rubbed finished catalog. Mention the course that interests you is Here is a coupon that is well worth 'mailing. It most and we will send you special information. particularly satisfactory on the lathe. It book- as in brings you-free-an interesting illustrated Read about the school that trains men for practical simply a matter of finishing other let that shows the tremendous opportunities in the and quick success. See how easy it is for you to work with filler, stain, shellac and Institute of get the training that will enable you to step to a cabinet radio industry and outlines the Radio splendid position and a handsome income. Mail varnish, but where the particular joy comes America's course of home study. the coupon right NOW. No cost or obligation. in is in the rubbing down process, which If you are really looking for a future-if you are is such a laborious task if done by hand. really out for Success-mail the coupon now. On the lathe it is simply a matter of mak- SCHO)LF 1. ENGIl ERING ing up a pad, similar to the one used in awaskCNEssv French polishing and with pumice stone and RADIO INSTITUTE 1905 Founded oil and the article in motion a beautiful OF AMERICA Dept. S.I.1128 rubbed finish can be acquired in a fraction Dept. G-11 326 Broadway required by hand. As a final Wis. of the time New York, N.Y. Jackson & E. Wells Sts. Milwaukee, finish, or after the final coat, rotten stone should be substituted for the pumice stone. SCHOOL OF ENGINEERING OF MILWAUKEE Dept. S.I. 1128 E. Wells and Jackson, Milwaukee, Wis. Without obligating me In any way, please mall tree illustrated RADIO INSTITUTE book, "Electricity and the One Best Way to Learn It." and particulars regarding the course I have marked with an X. OF AMERICA RESIDENT COURSES: Dept. G-1 l 326 Broadway ....Electrical Engineering. B. S. Degree. (3 years). City ....Commercial Elec. Eng.. (H. S. graduates 1 year New York -others 2 years). ....Armature Winding. Please send me your new booklet with ....Light. Motor Wiring and Testing. your Home ....Electrical Refrigeration. full information about ....Master Electrician. Study Course of Radio Instruction. ....Automotive Electricity. ....Radio Sales Ser+ice and Broadcasting. ....Home Laboratory Service. (Home Study Course). .... lam interested in your "Earn While You Learn" plan. Name Name Age Address Address Alcohol, shellac, rotten stone, some cotton City State waste, a small oil can and a piece of cheese City cloth are the only materials needed for the i Education polishing. Please say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com 668 Science and Invention for November, 1928

Science Probes Spiders' Secrets By UTHAI VINCENT WILCOX (Continued front paye 595)

like hint. They would leave to find a serious mate with another. Perhaps he just wasn't the marrying kind? In such a case, 75 \ the moral breaks down. Love among the LATEST spiders is an absorbing thing, in which the ladies do the absorbing by making a wedding RADIO supper of their husbands. Thus the masher - spider would love and lose, and thus it may CIRCUITS This be that he chose to ignore the females when 148 Page watching his friends as they were made into 500 meals for the female. These scientific facts, now being inten- ILLUSTRATIONS RADIO sively studied by scientists, not only reveal CATA LOG these facts as to love and hate among insects but may throw some light on physical ability, engineering skill and the substance BUY FOR DEALERS, COM- MUNITY SET BUILDERS of spider's webs. What couldn't man do FROM RADIO'S GENERAL if he were able to make ropes and cables OLDEST MAIL ORDER HOUSE REPAIRMEN with the approximate strength of a spider's AND AGENTS. web. Suspension bridges would be thrown We are the oldest established, exclusive radio mail order across on tiny cables about the size of house in the country. All orders are positively shipped within Be sure to get this great 148 -page book binder's cords and, being light and easy to twenty-four hours; quick, prompt, courteous service. We with net of radio parts, radio prices. anchor, there would be no limit to their carry a larger variety instruments, Radio accessories and radio findings than any other radio house in Specialty Company is radio's length. With the secret of making of cord the country. oldest radio parts mail order house in the after the manner of the wily spider, the You will find in Catalog No. 18 the largest assortment of country, and the new confidential prices whole course of engineering as we know it radio merchandise in this country. Radio Specialty carries on standard radio more radio parts and radio material than any other house in merchandise are the today would be altered! the country. You will find in this catalog positively the lowest of any radio house. It is the female spider that spins the web largest variety of radio merchandise. We are ready now to appoint additional being provided for that purpose with six If you are in need of certain small radio parts that other agents in all parts of the country. If you little tubes, called "spinnerets," at the radio and mail order houses do not bother to carry get the are contemplating end Rasco Catalog and you will find the small parts there, making big money of her abdomen. any- in radio merchandise, Into these tubes open hun- thing from a screw to copper ribbon, telephone diaphragms, be sure to get in dreds of glands, each of which supplies a as well as thousands of the small radio findings. touch with us at once. separate thread, and the spider manipulates We carry the Largest Variety of Small Radio Parts in the world, B UT we also carry All Standard Radio Merchandise. the threads by holding them between the RADiO SPECIALTY CO.. 100 PARK PLACE, NEW YORK "teeth" of her comblike claws.

Plane Broadcasts Radio Photo (Continued from page 624)

witnessed by R. Sanford Saltus, Jr.; George W. Humpfer, electrical engineer of WFI; John G. Leitch, Federal radio inspector, and Robert P. Hewitt. The transmission was made from the plane while at an altitude of

DAlO 'YOU say "who" when you should say 5,000 feet. The plane was piloted by Robert "whom"? Do you say "between you and P. Hewitt, assisted by John Bescher. The I- instead of "between you and me"? Do you mispronounce common words in your speech broadcasting apparatus was operated by John or use them incorrectly when you write? Build This IDEAL Flying Model of the G. Leitch. A 65 -foot fishline aerial was used Many a man has been held down all his for broadcasting, from the plane, and the life because of mistakes in English. make these mistakes "Spirit of St. Louis" entire program, including the picture signal You do not need to APERFECT 3 -ft miniature home, in the privacy of of the most famous Airplane any longer. Right at in the world: anybody can build and fly it. The impulses, were rebroadcast from WFI. your own room, you can make up the educa- IDEAL Complete Construction Outfit contains everything Although this is the first time that photo- tion you missed in the days when you should needed; all parts, fittings and materials, full plans. diagrams have been at school. and Instructions. The Model is guaranteed to fly when graphs have been transmitted by radio from International of English will correctly built; Complete Construction Outfit The School (West of Denver, Colo., and in Canada,$8.00) an airplane, it is not the first transmission öf teach you, just as it has taught thousands Ask your Dealer, or Order Direct 730 photographs by radio. The first transmis- of other men and women, by a simple new method which shows you instinctively which Plans for Model Airplanes sion of photographs by radio was accom- word to use and how to use it. Complete, accurate, 34 -size Plans, with plished in March, 1923, at which time pic- building-flying instructions, for any one of Mail Coupon for Free Booklet the following: New York-Paris; FOKKER tures were broadcast from the Naval Radio Curtiss; DeHAVILLAND; NC-4 Seaplane; Blerlot, Taube or Station, in Washington, and received at the INTERNATIONAL SCHOOL OF ENGLISH Nieuport: Cecil Peoli- Model Book Free with each Bulletin Building. This test was under the Division of the plan 25c International Correspondence Schools auspices of the North American Newspaper BoIg169 -F, Scranton. Penna. 64 -PAGE Alliance, in the presence of newspaper pub- Without cost or obligation, please send me full Book for Model Builders details of your home -study course in Contains plans for building Gliders anti lishers and scientists. Pictures of President D Good English Advertising Civil Service Racers; full information about Scale Models Harding, President Coolidge, and Gifford D Accounting U High School Subjects and most complete catalog of Parts, Supplies, Materials and Fittings for all Pinchot were received. The distance between Name kinds of Models Postpaid for the transmitter and receiver was 130 miles. Ideal Aeroplane & Supply Co., Inc. Address These pictures were transmitted using the 22-24 West 19th St., New York City Jenkins system, the invention of C. Francis Jenkins, of Washington, D. C. THE MIDGET SLIDE RULE ZIP -ZIP Shooter One of the problems that had to be over- instantly adds, subtracts, mul- tiplies, divides, solves propor- We Believe that every boy ought come in accomplishing this transmission was tion, gives all roots and pow- to train the eye and mind. the elimination of the effect of the vibration ers. Logarithms, Sines, Cos- We Believe that every boy ought ines, Tangents, Cotangents, etc. to be a good shot from the Whirlwind motor, and this was ac- Also gives decimal equivalents, We Believe that every boy ought lettered and numbered drill and to be happy. complished by attaining a high altitude and tap sizes. We Believe that every boY ought to running the motor with the throttle partly More than 110,000 sold, more dwn a Zip -Zip Shooter, which is scien- than 2.000 unsolicited testi- tifically and practically made. See your closed. The use of a phonograph record to monials. The Engine -divided dealer,boys; hap- avoid the use in the plane o the delicate scales are Oil whlteflnished aluminum and are grease and pens not in have them, waterproof. Diameter 4'. Price with Instruction Book, order from us. Zip -Zip and bulky "convertor" mechanism, is a typi- $1.50. Pocket Carrying Case. 50e extra, Cash or C.O.D. Shooter, 35c , or 3 for cal example of the ingenious schemes devised Catalogue free. Your money back if you are not satisfied. 51.00. .sr-- GILSON SLIDE RULE COMPANY. Stuart, Florida AUTOMATIC RUBBER CO., Columbia, S. C by the engineers working on this problem. Please say rou saw it in S('IFVCE a d I_VVE.VTIf').V

www.americanradiohistory.com J -..

Science and Invention for November, 192e C(9,

How to Save Coal! By C. D. KEELY (Continued front page 592)

Weight 37E lbs. For dows, present themselves. For an under- This standing of the proposition however, a ther- Only 'maily insulated building can be described 9 "F3' Junior as one in which has been isolated a portion $1242 New Model South Bend of the beat that would escape were the struc- Monthly Payment Back Geared Screw ture uninsulated. Cutting Precision Lathe Has power feed to carriage, gradu- I It is necessary to state here that the same ated compound rest, set over for This Lathe insulation that keeps heat within a structure taper turning, ,4 in. holt thru spindle Will in keeps ; and phosphor bronze spindle bear- Cut threads winter, heat out in summer that ings. Also made with 2g, 334, 4 and Do turning is, helps to maintain the coolness that is 454 foot beds. Boring Chucking created in consequence of the fact that the Priem $155.00; Down Payment $31.00 Make bushings interior is shaded from the sun. Monthly Payment $12 40 True Commu- Countershaf t and Equipment tators Included in the Price Undercut mica MATERIALS USED Also furnished in three types of motor Bore connect- drive with Ya H. P. Electric Motor opera- ing rode ted from ordinary lamp socket. Costa Finish pistons Materials of many kinds now are avail- lees than 2e an hour to operate. Reface valves able for thermal insulation. made Free Catalog No. 89-A shows 210 sizes and and hundreds Some are types of South Bend Lathes. Write for it. of other jobs from diatomaceous earth, some of wood SOUTH BEND LATHE WORKS fibre, some of sugar cane fibre, some of 466 East Madison Street South Bend. Ind., U. S. A. gypsum, some of cork and others are made from seaweed. These all are different in physical character. Some are loose fillers, some are rigid boards, and some are quilts. EARLE E. LIEDERMAN-"The Muscle Builder' They all, however, are applied to the same Author of "Muscle Building," "Science of Wrestling; "Secrets of Strength," " Here's Health," "Endurance," et& Only 4 Motions used in playing this fascinating places, or in the same places, of a building; instrument. Our native Hawaiian Instructors that is, they in teach you to master them quickly. Pictures are applied to or the walls, show how. Everything explained clearly. rte` and under, or somewhere beneath, the roof. Playin Half Hour Easy I. And the thermal insulating value of all of MUSCLES After you get the Ever if you don't four e a sy motions know one note from them is largely dependent on the same prin- 5 Cents a Piece y harmonious couhords printed t lemons ahe n2 ciple-dead-air cells. Walled up tightly in little practice. v No clear pictures make Wouldn't it be great if we could buy muscle. p usi ae,.yeaaoiek-aLayto some material, tiny cells of dead by the home on Yoowiedgem air are the bag-take them and paste them our needceald. ir. als yornu play. best known non-conductors of heat. All the shoulders? Then our rich friends with money to then you enroll buy them, sure would be socking us all over the lots. GIVEN -a sweet toned materials mentioned, when in place, contain But they don't cone that easy, fellows. If you HAWAIIAN GUITAR, Carrying Case varying quantities of dead -air cells. Hence want muscle You have to work for it. That's the WRITE AT ONCE for astrae. and Playing Outfit live offer and easy terms. a their value as insulators. reason why the lazy fellow never can hope to be postcard will du. ACT! Value Sts to $20 strong. So if you're lazy and don't want to work- No extras, earrylhtny included had OTHER Tenor Banjo t iolin. Tiple. Tenor Guitar, Ukulele. It was a search for an insulating material you better quit right here. This talk was never COURSES Banjo ukulele. Under well-known inntruesoes. that possessed certain ideal qualities that meant for you. FIRST HAWAIIAN CONSERVATORY of MUSIC. Inc. developed rock insulation. The ideal quali- 9th Floor, Woolworth Bldg., Dept. 240 New York. N. Y. I Want Live Ones Approved as a Correspondence School Under the Lacs of the ties are : bulk without weight, low cost, State of New York-Member National Home Study Connell. ease installation, I've been making big men out of little ones for of permanence and fire - over fifteen years. I've made pretty near as many safety. Bulk without weight is important strong men as Heinz has made pickles. My sycstem for this reason, it permits the installation of never fails. That's why I guarantee my work. a sufficient to do "the trick. That's why they gave me the name - amount of insulation to produce of "The Muscle Builder." I have the surest bet the maximum comfort and fuel saving. The that you ever heard of. importance of low cost, ease of installation, Everything in permanence and fire -safety, is, of course, What I'm Going To Do Radio Wholesale obvious. In just 30 days I'm going to increase your arm at one full inch. Yes, and add two inches to your We supply every radio need ROCK INSULATION - chest in the same length of time. But that's notó-, ing. I've only started; get this-I'm going to put from our mammoth stock of Rock insulation is manufactured in this knobs of muscles on your shoulders like baseballs. kits, parts and sets of latest 'manner : special, short length fibres are im- I'm going to deepen your chest so that you will design. Lowest wholesale prices. double your lung capacity. Each breath you take pregnated with ground gypsum, which is will flood every crevice of your pulmonary cavity Write for big, illustrated cata- a light weight, incombustible rock. The with oxygen. This will load your blood with red log "D-1." finished product is a fluffy material that has corpuscles, shooting life and vitality throughout your entire system. I'm going to give you arms and legs been described as "mineral feathers." It is like pillars. I'm going to work on every inner packed in paper bags, and is installed simply muscle as well, toning up your liver, your heart, AlliedRadio by pouring it in place from the sacks in etc. You'll have a snap to your step and a flash to your eye. You'll feel the real pep shooting up and CORD RATION which it comes. your old backbone. You'll 711 W. LAKE STREET, C.IICAGO down stretch out your Rock insulation, or as it more commonly big brawny arms and crave for a chance to crush everything before you. You'll just bubble over with is called, "gypsum dryfill," is installed inside vim and animation. POPULAR CJ POPULAR CHEMISTRY walls, over the lath and plaster of ceilings, Sounds pretty good, what? You can bet your old ukulele CHEMISTRY It's good. It's wonderful. And don't forget. fellow-I'm A Monthly Chemical Magazine and under roofs. Its use as side walls is not just promising all thla-I guarantee it. Well, let's get Latest chemical news, experiments, for- principally in connection with woodframe busy, I want some action --no do you. mulns, recent advancements in medicine, For new uses for X-rays, ultra-violet fight, residence construction, where the walls are Send My Free Book radrum, etc., every month. Three trial copies (back Issues), 30 completely filled with gypsum dry -fill, which "Muscular Development" cents. $1.00 per year. Free solubility embeds the wood of the frame in an in- chart and book catalog to immediate yearly subscribers. sulating, fireproofing material. Under roofs, -It's Free- the gypsum dry -fill is installed in one or Take It and read it. It's the peppiest piece of literature POPULAR CHEMISTRY CO. you ever lashed your glimmers on. And 48 full -page photee Dept. NB Swedesboro, N. two ways, either directly under the roof, as of myself and some of my numerous prize-winning pupils. This is the finest collection of strong men ever assembled a backup for mineral wallboard, or rock into one book-Look them over-Doctors, lawyers, mer- lath; or between the attic joists where it is chants, mechanics, and every line of trade you can think of. SHIP MODEL FOR $4 98 I swear you'll never let this book get out of your hands again. A poured in such a way that it rests on the And lust think-you're getting It for nothing. Don't hesitate- l'he Wcrld's Largest Builders of Ship Models lath of of there's no strings attached to It. Crab it. will supply you with all necessary parts, cut to and plaster the ceilings the rooms Take your pen or pencil and fill out the coupon-But de fit and -eady to assemble, and you can build a below. it now-before you turn this page. lMú heautlfll model of the historic Santa Marta, - +1 La Pina, or Mayflower for $4.98, plus a few It is well to note again that gypsum dry cents pistage. No tools are needed except a fill simply is poured into place. It is not EARLE E. LIEDERMAN 4ä. small hammer. Full directions with each kit. Parts for the Constitution (Old Ironsides) may nailed, fitted, sawed or mixed with water. Dept. 2711 305 Broadway New York City be had for 86.98 plus postage. Send for our be insulated beautifully illustrated catalog. No obligation From the bags to the place to EARLE E. LIEDERMAN, Models, arc., 3818 Baring St., Dept. S.S., Pbila., Pa. is all there is to its installation. And though Dept. 2711, 305 Broadway, New York City Miniature Ship Dear Sir-Please send me absolutely FREE and without the dry -fill itself is a fluffy, light weight any obligation on my part whatever, a copy of your latest substance, it does not dust or settle after book, Muscular Development." (Please write or print WrestlinV BooK FREE plainly.) Learn w ,.,Cling at home from former wo Id's champions it is in place. The gypsum impregnated Farmer Burns end Frank notch. Free book tells how. Name revealed. Be steon healthy. fibres come together to form a blanket that Secret hnldo. blocks tricks age. Handle big m easily. Write for tree book. State contains myriads of tiny dead -air cells. Street -mer Berns School, 3798'Railway$Idt.,Omaba, Neb. (Name of manufacturer on request.) (2Iti' State Please say you saw it in SCIF..\'CF and I .NVENTION

www.americanradiohistory.com 670 Science and Invention for November, 1928

Opportunity Ad -lets YOII will find many remarkable opportunities and real bargains in these columns. It will pay you to read and investigate the offerings made every month by reliable firms, dealers and amateurs from all over the country. No matter what -you may be seeking, whether supplies, automobile accessories, the opportunity to make money, or anyth ing else, you will find listed here the best and most attractive specials of the month. Advertisements in this section twelve cents a word for each insertion. Name and address must be included at the above rate. Cash should accompany all classified advertisements unless placed by an accredited advertising agency. No advertisement for less than 10 accepted. words Ten per cent discount for 6 issues, 20 per cent discount for 12 issues. Objectionable or misleading advertisements not accepted. Adver tisements for the January issue must reach us not later than November 5th. EXPERIMENTER PUBLISHING CO., INC., 230 Fifth Avenue, New York, N. Y.

'Advertising Airplanes, Aviation Chemistry (Cont.)

Model Airplane Engines: t/a h.p. in 3 lhs.; 1 h.p. in Learn Chemistry Get into Advertising. Learn quickly at home. Experi- at Home. Dr. T. O'Conor Sloane. text books used. 5 lbs. We buy patentable improvements in engines. Cir- noted educator and scientific authority, will teach Our ence unnecessary. New, easy plan. No culars free. Mfg. home you. work. established school. Send name and Dynamic Co., First Nat'l Bank Bldg., study correspondence course fits you to take a posi- Practical Old Chicago. tion as chemist. address for interesting free booklet. Page -Davis School See our ad on page 582 of this issue. Chemical Institute of New York, 16 E. 30th St., New of Advertising, Dept. 533-B, 3601 Michigan, Chicago. York City. Model Airplanes and supplies. Send dime for package of supplies and propellor; send stamp for price list. Slade' Airplane Co., 161 Royal Ave., Hawthorne, N. J. Your Chemical problems solved and working process furnished for Five Dollars. Write me. W. Stedman Rich- Agents Wanted ards, Consulting Chemist, Box 2402, Boston, Maas. Build our wonderful one -place monoplane adapted to motorcycle or small aircooled motors. Detailed blueprints $2.00. Hawley Aircraft, 3366 Griot, San Diego, Calif. Don't sell for others. Employ agents yourself. Make your own products. Toilet Articles, Household Specialties, Correspondence Courses etc. 500% profit. Valuable booklet free. National Biggest, Best Catalog Model Airplanes, Parts, Supplies; Scientific Laboratories, 1975W Broad, Richmond, Va. 5c postpaid. Ideal Company. 23 West 18th Street. New York. Used correspondence school courses sold on repurchase basis. Also rented and exchanged. Money -back guarantee. Catalog free. (Courses bought). Lee Mountain, Pisgah, Agents--Best seller; Jem Rubber Repair for tires and Alabama. tubes; supersedes vulcanization at a saving of over 800 per Books cent; put it on cold. It vulcanizes itself in two minutes and is guaranteed to last the life of the tire or tube; sells to ter ery auto owner and accessory dealer. For particulars how to make big money and tree sample, address Amazon Books. Magazines, Art Publications in French, English, Detectives Rubber Co.. Philadelphia, Pa., Dept. 601. Spanish. Photo novelties, etc. Samples, lists. 20 cents in stamps. Villaverde Co., Dept. 206, Box 1329, Havana, Cuba. Detectives Earn Big Money. Travel. Excellent opportunity. Make secret investigations. Great demand every- 66 Miles on I Gallon-Sensational New Moisture Gas where. Experience G-863, Free-My illustrated Circulars on Nett thought, Selfcul- unnecessary. Write American Detective Saver. All autos, 1 Free to Introduce. Critchlow, Sy Rem, 2190 Broadway, N. Y. Wheaton, Ill. ture. Healing, Yogi Philosophy, Occult. Mystic and Scien- tific Books. Martens Publisher, Inc., Burlington, Iowa.

Be Independent. Make, sell your own goods. Inunense Fruit eating and fruit juice drinking.. Most effective Engines, Motors, profits. Catalog dependable Formulas, special selected book printed. cts. Free H. E. Wildman, Dynamos Block, 50 catalog. agents' best sellers Free. T. Lustro, 626 Reaper 1722:1 Pine, Los Angeles, Calif. Chicago. Make Electric Motors-half and one horse-power. A. C. induction motor winding models show connections plain sight. Learn quick easy. Dept. C, Gaines Bros., Galnes- $12.00 Daily Showing New Linen -Like Tablecloth. Wash ville, Texas. like oilcloth. No laundering. Sample free. Bestever, Business Opportunities 121 Irving Park Station, Chicago. Sell By Mai I!-Books, Novelties, Bargains! Large Profits! Particulars FREE! E-Elfeo, 525 South Dear- For Inventors Mirrors Resilvered at Home. Costs less than 5 cents born, Chicago. per square foot; you charge 75 cents. Immense profits plating autoparts, reflectors, table ware, stoves, refinishing Write Wealthy prospective patent buyers may buy your inven- metalware, etc. Outfits furnished. Details Free. Import your own goods. German export magazine pub- tion. List of names $2. W. D. Hawn, 22,720 Woodward, Sprinkle, Plater, 955, Marion, Indiana. lished in English, offers numerous bargains latest nncel- Ferndale, Mich. ties; opportunities obtaining profitable agencies. Copy 60e. Square Deal Supply, V-246 Fifth Avenue, New York. Gold Leaf window letters and script signs. No experi- Unpatented Ideas Can Be Sold. I tell you how and ence; 500% profit. Samples free. Meyer writes -5 days help you make the sale. Free particulars (Copyrighted t. profits-$141.36. Consolidated, 69-R, West Van Buren, Free Book. Start little Mail Order business, Hadwil. Write W. T. Greene, 808 Baltic Bldg., Washington, D. C. Chicago. 5A-74 Cortlandt Street, N. Y. Inventions Commercialized. Patented or Unpatented. Artists and Art Students are printing 250 signs and Write Adam Filter Mfg. Co., 205 Enright, St. Louis, Mo. I pay my agents $90 a week just to wear and show pictures an hour without machinery. Sample and par- ray beautiful new Free raincoat and give away Free ticulars 10c. Straco-1015 Mulberry, Springfield, Ohio. King, 230 S. Wells, hats. Write today for yours. Robert Free Book on Selling Unpatented Inventions. Sterling Dept. AD -11, Chicago. Buck, S-629 F. Washington, D. C. Cameras and Photography Supplies $60-$200 a week. Genuine Gold Letters for store win- Inventors. Use our special service for presenting your dows. Easily applied. Free samples. Liberal offer to invention or patent to manufacturers. Adam Fisher Mfg. Co., 441 B.. North Clark, Co., 205-A Enright, St. Mo. general agents. Metallic Letter money in quickly Louis, Chicago. Make Photography. Learn at home. Spare or full time. New plan. Nothing like it. Ex- perience unnecessary. American Schpol of Photography, Dept. 5333, 3601 Michigan Avenue. Chicago. Big money and fast sales. Every owner buys gold ini- Help Wanted tials for his auto. You charge $1.50; make $1.35. Ten orders daily easy. Write for particulars and tree samples, American Monogram Co.. Dept. 71, East Orange, N. J. Silvering Mirrors, French plate. Patented Process. Chemistry easily learned. Immerse profits. Plans Free. Wear, Excelsior Springs, Mo. Succeed With Your Own Products. Make them yourself. Formulas, Processes, Trade -Secrets. 411 lines. Catalog, Catalog listing 2500 illustrations, chemists supplies. Men-Experience Circulara free. D. Thaxly Co., Washington, D. C. 5000 chemicals, 1000 scientific books sent for 58e. Labora- unnecessary; travel; make secret in- tory Materials Company, 635 E. 71st St., Chicago. vestigations; reports; salaries; expenses. Write American Foreign Detective Institute, 304, St. Louis, Sfo.

$50.00 Weekly easy, applying Gold Initials on Automo- Chemical out- biles. No experience needed. $1.95 profit every $1.50 $4.00-Astounding chemical offer-$4.00: job. Free Samples. "Raleo Monograms," R1043 Wash- fit consisting of 100 different expensive laboratory chemi- Boston, Mass. cals sufficient quantities for hundreds of experiments, Help Wanted-Instructions ington, including many pieces of apparatus. Prepaid anywhere U. S. cash, or C. O. D. Easily worth $20.00. Cheml- rats guaranteed pure. Send order to the Swimmer Chemi- Men, get Forest Ranger job; $125-$200 month and $10 daily silvering mirrors, plating and refinishing lamps, cal Co., Est. 15 years, 1500 St. -harks Ave., Brooklyn, home furnished; hunt, autos, beds, chandeliers by new method. fish, trap. For details, write reflectors, Outfits New York. Norton Inst., 1541 Temple Court, Denver, furnished. Write Gunmetal Co., Ave. D, Decatur, Ill. Colo.

Experimenters study spectrum analysis. Grating type Earn $25 Weekly. Spare Time. Writing for Newspapers We pay $48.00 a week, furnish auto and expenses to direct vision spectroscope, $5.00. Money refunded if not and Magazines. Experience unnecessary. Copyright Book, introduce our Soap and Washing Powder. Buss -Beach satisfied. Scientific Specialties Co., 304 S. West St., "How to Write for Pay." Free. Press Reporting In- Company, Dept. A 185, Chippewa Falls, Wis. Sfadi son, Indiana. stitrne, 987. St. Louis, Mo.

water safe? tells you Bankrupt-Rummage sales. Stake $500.00 monthly. We Is your "Amateur Chemist" - 10e, Thompson -Allen Laboratories, Shamokin, Pa. start you furnishing everything. Experience unnecessary. How to Entertain Robey, Desk 205, 1945 Wabansia, Chicago. Flameless Light. Formula for making a cold light lamp furnished on receipt of $1.00. E. Peart, 84 Hoyt Plays, musical comedies and revues, minstrels, comedy Make and Sell Felt letters, emblems, armbands etc. Ave., Lowell. Mast and talking songs, blackface skits, vaudeville acts, mono- Outfit includes designs, alphabets and materials to make logs, dialogs, recitations, entertainments, juvenile plays and stamp patterns. Felt included with outfit $1.00. and songs, musical readings. make-up goods. Catalog Ohmer D. Vance, 12181/2 Wabash Ave., Terre Haute, Big Chemical Mail, 5e. Walker, 1519 Allison, Wash- free. T. S. Denison Co., 623 So. Wabash, Dept. 99, Indiana. ington, D. C. Chicago. Plea sr say you saw it in SCIENCE and INVENTION

www.americanradiohistory.com Science and Invention for November, 1928 671

Instructions Moulds Patents Wanted

Learn-Decorating-Sign Painting-Paper Hanging- Moulds Making Toys. See ad on page 671. Miscel- Inventions Commercialized. Patented or Unpatented. Card Writing. Prctical Training-Oldest school in United laneous. H. C. Schiereke. Write Adam Fisher Mfg. Co., 205 Enright, St. Louis, Mo. States. Chicago Painting School -434 North Clark Street, Chicago, Illinois.

Life Character Reading, . lersonal Horoscope and Voca- tional Analysis delineated from Berth Date and Hand - st riling. A 0 page reading; Price $1.00. Miss J. K. Work for "Uncle Sam." Get Government Jobs. Men- Fifrick, P. O. Box 147, Alarinette, Wis. m omen, 18 to 50. $105.00 to $283.00 month. Steady, Old Coins pleasant work. Short hours. Paid vacation. No layoffs. Common education usualL' sufficient. andidates coached without leaving honte. Fu I particulars and 32 page book- Free. Write iuunedi at el:. 'roday sure. Franklin In- 7,30 4, Y. California Gold, quarter size, 27e; half -dollar size, stitute, Dept. J Rochester, N. Columbian nickel and catalogue, 10c. Norman Shultz, Box Photography 746, Salt Lake City, Utah.

Learn Chemistry at Home. Dr. T. O'Conor Sloane, Big Opportunities! Learn at home; Motion Picture noted educator and scier title authority, will teach you. Photography, portrait. Commercial or news photography; Our home study correspor.detire course fits you to take a write for catalog. New York Institute of Photography, position as chemist. See our full page ad on page 582 of Dept. 82A, 10 W. Md St., N. Y. this Issue. Chemical ln.s_itute of New York, 16 E. 30th Old Money Wanted St., New York City. Have you a Camera? Write for free sample of our big magazine, shoving how to make better pictures and earn money. American Photography, 118 Camera House, Bos- $2 to $500 Each paid for hundreds of Old or Odd Coins. ton, 17, Mass. Wanted. Men, Quality for Post -office Laborer Job, Keep all old money, it may be very valuable. Send 10e for $125-$133 month. Write, Ozment Inst., 293 St. Louis, new illustrated coin value Book 4x1). Guaranteed Prise. Missouri. Get Posted, we pay Cash. Clarke Coin Company, 14 Street, LeRoy, N. Y. Photo plays Wanted Mail Carriers-Clerks-Railway Postal Clerks. $158.00 to $225.00 month. Steady jobs. Men, 18-45. Sample coaching free. Write immediately. Franklin Institute, $ S S For Photop lay Plots, Stories accepted any form, re- Dept. J 15, Rochester, N. Y. Patent Attorneys vised, criticised, copyrighted, marketed. Estab. 1917. Booklet free. Universal Scenario Co., 223 Western & Santa Monica Bldg., Hollywood, Calif.

Patents procured at reasonable rates with time to pay. Inventions Wanted Sales negotiated. Staff of registered attorneys and engineers. A complete service for Inventors. Write for particulars. Inventors Service Bureau, Box 1648, Wash- ington, D. C. Printing Outfits and Supplies Inventions Commercialized. Patented or Unpatented. Write Adam Fisher Mfg. Co., 205 Enright, St. Louis, SIo. Print Your Own Cards? Stationery, Circulars, Adver- Patents. Booklet free. Highest references. Best re- tising, etc. Complete outfits, $8.85; Job Presses, $11, sults. Promptness assured. Watson E. Coleman, Patent $20; Rotary, $149. Print for others; big profit. Easy Attorney, Washington, D. C. riles furnished. Write for catalog Presses, Type, Paper, Magic and Games etc. Kelsey Company, J-0, Meriden, Conn.

Patents. Time counts in applying for patents. Don't K lever, komical, kalling kards! "Every Kard a Laugh." risk delay in protecting your ideas. Send sketch or model IOc brings complete assortment with illustrated Novelty for instructions or write for Free book, "How to Obtain a Printing, Engraving, Multigraphing Catalog. Novelty Products, 2050 W. Davison, Detroit, Patent" and "Record of Invention" form. No charge for Mich. information on how to proceed. Communications strictly confidential. Prompt, careful, efficient service. Clarence A. O'Brien, Registered Patent Attorney, Security Banjo 200 Letterheads and 100 Envelopes, $1.10, postpaid. Building (directly across street from patent office). Wash- Oberman Company, Box 1268, Chicago. "The Book of 1000 Wonders" will be sent postpaid for ington, D. C. See page 641. 1Oc. Explains many myrtifying tricks with Coins, Cards, 1000 Envelopes 644 Commercial Handkerchiefs, etc. you ,an do. Also, contains completed ' $2.00 Printed. Pearl Catalog of Magic Tricks. Jokes, Puzzles, Books, Escapes, Press1490 Eddy, San Francisco. Mindreading Acts, Spiritualistic Effects, Illusion Plans, Inventors who derive largest profits know and heed cer- Curios and Imported Novelties front many foreign lands: tain simple but vital facts before applying for Patents. Large . assortment, lowest prices. You will amaze and Our book Patent Sense gives those facts; free. Lacey & mystify your friends! Send 10e today. Lyle Doublas, Lacey, 644 F. St., Washington, I). C. Established 18x9. Station A-11. Dallas, Texas. Salesmen Wanted

"Inventor's Advisor," Valuable Patentbock sent free. P unchboard Free with $25 order our large die box. Send 20e for Labiner, 3 Park Row, New York. Salesmen. $200 weekly. Liberal platy our large catalogue of tricks, puzzles, wigs, sensational assures sales. Latest assortments. Nothing to carry. escapes. Oaks Magical Co.. Dept. 549, Oshkosh, Wis. Full commissions on repeats. SI & L Sales Co., 301 W. Adams, Chicago, Patents-Send for form "Evidence of Conception" to be signed and witnessed. Form, fee schedule information free. Lancaster and Aliwine. Registered Patent Attorneys in Punchboard Salesmen. 2 hours daily. $100 every week. United States and Canada, 242 Ouray Bldg., Washington, New line. Lowest prices. Full commission on repeat busi- D. C. ness. Catalog Free. Puritan Novelty Co., 1409 Jackson, Male Help Wanted Chicago.

Patent, Trade -Marks, Copyrights. Reliable services by "Try It" "Punch Bali" 2 Brand New Machines that's Big Pay! South American Work, American firms pay an personal fare, expenses. South American Service Bureau, 14,600 experienced practitioner devoting attention to startling country. $125-$200 Weekly. Every store pros- each case. Inquiries invited. Reference furnished. B. P. pect. Pocket Outfit Free. Ad -Lee, 827 Wabash, Chicago. Alma., Detroit, Mich. Fishburne, Patent Lawyer, 525-D McGill Building, Wash ington. D. C.

Firemen, Brakemen, Baggagemen (white or colored), Sleeping Car. Train Porters (colored), $150-$250 monthly. Patents Procured; Trade Marks Registered-A com- Song Poems Experience unnecessary. 897 Railway pureau, East St. prehensive experienced, prompt service for the protection Louis, Ili. and development of your ideas. Preliminary advice gladly furnished without charge. Booklet of information and form for disclosing Idea free on request. Irving L. Song -poem Writers. Address Monarch, 236 West 55th, 11fcCathran, 202 Owen Bldg., Washington, D. or 41-T Dept. 233. Nest York. Steamship positions-Men-Women- Good Pay. Experi- C., ence unnecessary. List of Positions Free. Box t22-11, lark Row, New York. Mount Vernon, N. Y. Song Poem Writers, Write Sequoia Songwriters' Service. Sherman Branch, Los Angeles, Calif. ADAM E. FISHER, Registered Patent Attorney, in business 25 years; references; personal attention and promptness assured; Dept. E. 205 Enright, St. Louis, Mo. Miscellaneous Song Writers Monroe E. Miller, Ouray Bldg., Washington, D. C. Patent Lawyer. Mechanical, Electrical Expert. Booklet Musi ea Instruments, radio model airplanes, engines. and Priority Record blank gratis. Year Complete Song or Song -Poem will be immediately Circulars free. Pract lead Novelty & Amusement Co., First returned if not accepted. Chester Escher, Music Pub- Nat'l Bank Bldg., Chicago. lisher, 1547 Broadway, New York City. Patents-Write for Free Instructions. Send drawing or Model for Examination. Carl Miller, Registered Patent Song Poem or melody writers-Rave "real" proposition. Luminous Paint-Dotons of uses. Clocks, house -num- Attorney (former Patent Office examiner). 211-B McGill Hibbeler, D 24, 2104 N. Keystone, Chicago. bers, keyholes, light -switches, etc. Large bottle 25e coin. Building, Washington, D. C. Chemix Company, Box 1811, Denver, Colo.

Business Information of every character. \\'e divulge Stamps and Coins actual supply source of American made goods, how to sell Patents locally, by mail or though agents. Chemical Analysis, money business opportunities Formulas, -saving information 100, All Different, 3 Write for catalog. Business Information Syndicate, 544 W. Stamps, cents. S. I. Quaker Adeline St., Oakland, Calif. Inventions Commercialized. Patented or Unpatented. Stamp Company, Toledo, O. Write Adam Fisher Mfg. Co., 205 Enright, St. Louis, Mo.

Forms to cast Lead Gold lers, Indians, Marines, Trappers, Animals, 151 kinds_ Send l0c for illustrated Catalogue. Inventions commercialized, bought, sold. Patented or Telegraphy H. C. Schiereke, 1034 -72nd St., Brooklyn, N. Y. unpatented. General Engineering Corp., 2652 Greenleaf Ave.. Chicago. Telegraphy-Both Jforse and \fireless-taught thor- Private party desires purchase elementary electrical or oughly and quickly. Tremendous demand. Big salaries. ground aviation Home Study course with copyrights. Box Profit on your patent. 230 page book $2 on approval. Wonderful "opportunities. Expenses low; chance to earn 280, Science and Invention, 230 -5th Avenue, New York Tells how to profitably sell patents, new ideas. Patent part. School established fifty years. Catalog free. City. Enterprises, California Bldg., Los Angeles, Calif. i Dodge's Institute, Stone St., Valparaiso. Ind. Please say you saw i.t in SCIENCE and INVENTION

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Wide Selection of Beautiful Cabinets AC or Battery Sets 30 DAYS HOME TRIAL TRAGE MARK REGISTEREDC Ric.dy designed. gen - Mlle walnut consul. CATHEDRAL TONED, SUPER SELECTIVE, POWERFUL DISTANCE GETTERS of finest type. Eler tro-dynamic or mag Celebrating its 9th successful year, bum -free operation, tremendous netic parer cone. oe long air col'umr America's big, old, reliable Radio "kick" on distant stations and speaker. Marvelou- Corporation springs a genuine razor -edge selectivity-with its value. sensation in high-grade sets. With costly sturdy construction, latest its latest, Super -powered. 1 -dial features, including phonograph Miracos-the pick-up connec- All Electric BIG DISCOUNTS tion, ease of tun- wholly self-con- Exclusive Territory ing, beauty, and tained, hum - to User -Agents on economy - a free, AC -8 and Miraco will A popular walnut AC -9, using AC BATTERY OR AC make you the Boy Console, wit h drop- tubes or the new ELECTRIC OUTFITS envy of many leaf desk. Beautiful 8 -tube models two-tone finish. Icare whose radios bargain! for batteries or Eliminators-you cost 2 to 3 times as much! AC -8-$71..5(1 are guaranteed values and savings Many thousands of Miracos- Uobs ..blc ali,,' in a 3 - unsurpassed in the fine set field. bought after 30 day home com- year guaranteed Super, Shielded Metal Chassis Compare a Miraco with highest - parisons-are cutting through (similar to AC -9 shown Beautifully graceful priced radios, for 30 days in your locals and getting above). Spinet console, genuine coast to coast two-tonewaln ut.Choicr home. Surprise and entertain with the tone and power of costly of speakers. Also cornet, your friends-get their opinions. sets, their delighted users report. in Electric Phonograph - Unless 10070 delighted, don't buy Miracos are laboratory -built with Radio Combinations. it! Return everything-the com- finest parts, and embody 9 years' plete outfit-at our expense. Your actual experience in constructing decision is final-absolutely! fine sets. Approved by Radio's Also New, More Only exceptionally fine radios, highest atithoritiei. Powerful Battery of the very latest approved type, at Deal Direct with Sets rock -bottom possibly Big Factory prices, could Everything reaches you splendidly packed The newest and latest in hack up so liberally unconditional and rigidly tested to insure your instant battery operated sets, de- A new - type arm - chair a guarantee. Send coupon now for enthusiasm. Enjoy the outfit 30 days- signed with same ad- console. Genuine walnut. vanced features used in Amazing Special Factory Offer! then decide. Liberal 3 -year guarantee on elect rie sets! Same wide Very pretty. Low priced. each set. Play safe, save lots of money, choice of cabinets. High- Electro -Dynamic or Mag- Don't Confuse with Cheap Radios and insure satisfaction by dealing direct est q uaiity, amazingl ylow netic -Power Speakers. with Radio's old, reliable builders of fine priced! With its rich, Blear Cathedral tone, sets -9th successful year. 8 -tube Battery At right, a Lo- IMPORTANT NOTICE! Super Shielded Boy console, '30 Day Free Trial" offers usually are money -back guarantees frequently only on the "set." Metal walnut finish, Please understand that unless you are thoroughly pleased we pay return charges and refund Chassis ,24..88 thatcostslittle. the FULL purchase price on both the "set" and ALL equipnunl-tubes, cabinet, speaker, antenna (also on batteries or eliminators with ultra -8 sels). Could any offer Tubes. batteries or elim- A gem l be fairer? inators and cabinets are extra. 30 days home trial MIDWEST RADIO CORP'N, 409 -AN MiracoBldg., Cincinnati, Ohio on EVERYTHING! Above. popular inexpensive BEAUTIFULLY ILLUSTRATE 'ATALOG, AMAZING SPECIAL FACTORY OFFER, TESTIMONY OF combination. Set on Table NEARBY USERS-All the proof you want-of our honesty, fairness. size, financial integrity,radio Speaker (sold separately). experience and the performance of our sets-including Amazing Factory Oifer--sent with catalog. Metal or wood compact zple,,,.^ style cabinets. Wood DDIIRDRISRu.lu cabinets in walnut or MIDWEST RADIO CORPORATION THIS COUPON new shaded silver - Pioneer Builders of Sets -9th Successful Year IS chrome finishes. Cathe- NOT reel 409 -AN Miraco Bldg., Cincinnati, Ohio AN ORDER dral Electra -Dynamic r Magnetic- Power WITHOUT OBLIGATION, send free catalog, Amazing Special Factory Oiler, Deaker to match: testimony of nearby users, etc. D User Agent Dealer J Check here it interested in an EXCLUSIVE TERRITORY PROPOSITION NAME ADDRRSS