William Dubilier Walter P

JANUARY 25 CENTS .)13714`. cience and nventrioti:

The City of Tomorrow In This Issue: "Casey" Jones David Belasco William Dubilier Walter P. Chrysler II

Stock Stew. Ssivse01.0c. ajn. On every page of this big catalog for 1930 you will find radio Chicae:o3.Wle $ merchandise of unusual interest-priced at the lowest wholesale quotations. No radio enthusiast or dealer can afford to be without it. The latest radio devices and improvements are illustrated - sets, accessories, parts and kits-at price -saving reductions that spell the buyer's opportunity. Astounding offerings in new, humless, Screen Grid A. C. all -electric and battery operated sets; beautiful and artistic consoles; dynamic speakers of great volume and rich tone; and everything considered standard in accessories, parts and kits. The startling values listed in this Catalog are made possible by our tremendous buying power, low cost of operation and willingness to take a conservative profit. Quick service, expert cooperation and unusual satisfaction are assured to every customer. Don't fail to get this FREE wonder book. It will save you big money. Mail the Coupon Today!

CATALOGFREE,

_ MP Mr Ow Stock Store P(ENgtpChicago Salvage pept. 128 Ill. Sos So. StateSt., Chicago, I (free of chargeand postpaid) Kindly send me Book ofRadio Bargains. your new148 -page Name...... Address...... State ...... City ...... MAI CHICAGO SALVAGE STOCKSTORE c'WORLD'S LARGEST RADIO STORE 509 So.State St. Dept. 128 Chicago, III.. Science and Invention

.11ziays outside of things -that's where I was lust twelve short months ago. Ijustdidn'thavethe cash. that was all.No theatres, noparties, no good restaurants. No real enjoyment of life.I teas just getting bv, just existing. What a difference today!I drive my own car, have a good bank account,enjoyallthe amusements I please.

I Couldn't Get the GoodThings of Life Then I Quit My Job and "Found" Myself ! HOWdoes a man go about making "I've just been figuring out your fam- measly little clerical job and devoted my more money? IfIasked myself ily budget, Bill,for a salary of twenty- full time to my Radio business. that question once, I asked it a hun- eight a week.I've figured it several ways, Since that time I've gone right on up, al- dred times! so you can take your pick of the one you ways under the watchful guidance of my I know the answer now-you bet.I like best.Here's Budget No. 1:I figure friends at the National Radio Institute. They know the way good money is made, and you can afford a very small unfurnished would have given me just as much help, too. I'm making it.Gone forever are the days apartment, make your payments on enough ifI had wanted to follow some other line of of Radio besides building my own retail busi- cheap shoes, cheapclothes,walking plain, inexpensive furniture to fix suchan home to save carfare, pinching pennies to ness.suchasbroadcasting, manufacturing. apartment up, pay your electricity, gas and experimenting. sea operating. or any one of make my salary last from one pay-day to water bills, buy just about one modest out- the next one. the score of lines they prepare you for. And I own one of the finest fit of clothes for both of you once each to think that until that dayIsent for their Radio stores you ever saw, and Iget al- year, and save three dollars a week for eye-opening book. I'd been wailing, "I never most all the Radio service and repair work sickness, insurance, and emergencies. But had a chance!" in town.The other Radio dealers send you can't eat.And you'll have to go with- Now I'm making real money.Louise and their hard jobs to me, so you can see how out amusements until you can get a good, I have been married six months. and there 1 stand in my line. substantial raise in salary." wasn't any kidding about budgets by Mr. But-it's just a year ago that Sullivan when we stepped off,either. I'll I was a I 'began to turn red as fire. bet that today I make more money than the poorly paid clerk.I was struggling along "That budget isn't so good after all," he old boy himself. on a starvation salary until by accident my said, glancing at me; "maybe Iltxlget No. Here's a real tip.You may not be as bad eyes were opened and I saw just what was 2 will sound better -- off asIwas. Rut, thinkit over-are you the matter with me.Here's the story of "That's enough. Mr. Sullivan." Isaid. satisfied? Are you making enough money, just how it happened. "Have a heart.I can see things pretty at work that you like?Would you sign a clearly now ;things Ivas kidding myself contract to stay where you arc now for the One of the big moments of my life had about before.Let me go home and think next ten years. making the same money? If come.I had just popped the fatal ques- hisover." And home Iwent, my mind not, you'd better be doing something about tion, and Louise said, "Yes!" in a whirl. it instead of drifting. This new Radio game isa live -wire field Louise wanted to goin andtellher of golden rewards. The work, in any of the father about it right away, so we did.lie .\t home I turned the problem over and 20 different lines of Radio. is fascinating, ab- sort of granted when we told him the over in my mind.I'd popped the question sorbing, well paid.The National Radio In- news, and asked Louise to leave us alone. at Louise on impulse without thinking it stitute-oldest and largest Radio home - And, my hart began to sink -as I looked out. Everything Mr. Sullivan had'said was study schoolinthe world-will train you at his face. gospel truth.I couldn't see anything to do, inexpensivelyinyour own home to know "So you and Louise have decided to get Radio from A to Z and to increase your any way to turn.But I had to have more earnings in the Radio field. married." he said to me when we were money. Take another tip-no matter what your alone."Well, Bill, just listen to me. I've I began to thumb the .pages of a maga- plans are. no matter how much or 1 little watched you often here at the house with zine which was lying on the table beside me. you know about Radio-clip the coupon be- Louise and I think you are a pretty good. Suddenly an advertisement seemed almost low and look their free book over.It is filled upstanding young fellow. I knew your to leap out at my eyes, an advertisement tell- with interestingfacts,figures, and photos, father and mother, and you've always had ing of big opportunities for trained men to and the information it will give you is worth a good reputation here, too.But just let succeed in the great new Radio field. With a few minutes of anybody's time.You will me ask you just one question-how much the advertisement was a coupon offering a place yourself under no obligation-the book do you make?" isfree andisgladlysent to anyone who big free book full of information.I sent wants to know about Radio.Just address "Twenty-eight a week," I told him. the coupon in, and in a few days received J. E. Smith, President. National Radio Insti- He didn't say a word-just wroteit a handsome 64 -page hook. printed in two tute. Dept. OAS, Washington. D. C. down on a piece of paper. colors, telling all about the opportunities in "Have you any prospects of a better job the Radio field and how a man can prepare or a good raise some time soon?" he asked. quickly and easily at home to take advan- "No, sir ; J.E. SMITH. President, I. can't honestly say thatI tage of these opportunities. I read the book National Radio Institute. have." I admitted."I'm looking for some- carefully, and when Ifinished itI mad( Dept. OAS, Washington. D. C. thing better all the time, though." my decision. Dear Mr. Smith: "Looking, eb?How do you go about What's happened in the twelve month, Please sand me your (i4 -page free book, it?" since that day seems almost like a dream printed in two colors, giving all information Well, that question stopped me. about the opportunities in Radio and how I to me now. For ten of those twelve months can learn quickly and easilyat home to How did 1?I was willing to take a I've had a Radio business of my own! At take advantage of them.I understand this better job if I saw the chance all right, but first. of course, I started it as a little prop- request places me under no obligation, and Icertainly had laid no plansto make osition on the side, under the guidance of that no salesmen will call on me. such a job for myself. When he saw my the National Radio Institute, the institu- Name confusion he grunted."I thought so." he tion that gave me my Radio training.It Address said.Then he held up some figures he'd wasn't long before I was getting so much been scribbling at. to do in the Radio line thatI quit my T .svn state UP -TO -THE-MINUTE ARTICLES in this' Issue by WELL-KNOWNAUTHORS General Science Aviation Holding Down the R-101 772 What I Found on Board the R-101 780 What Famous Men Predict for Science in 1930 778 By Augustus Post What I Found on Board the R-101 780 Mid -Ocean Aircraft Stations 789 By Augustus Post Newest Ideas in Aviation 792 782 New Aviation Toys 797 Smoke-What It Costs Taxpayers of a Great City How to Build a Record -Winning Model Plane 808 Around the World in 17 Hours' 783 By Hi Sibley The City of Tomorrow-The Dream of Le Corbusier 784 By II. Winfield Seeor Chemistry and Electricity Would You Believe It 788 A Quarter Million Volts 795 Mid -Ocean Aircraft Stations 789 What Two Boy Chemists Did 796 In the Spotlight of Science 790 Illuminated Table Decorations You Can Make 803 Newest IdeasinAviation 792 How to Prepare Dyes and Pigments 810 794 By Eugene W. Blank Henry Ford's Museum Will House Edison's Early Shop.. Toy Railway Tunnels Easily Made 814 Made -to -Order Weather for Your Home 795 By Dr. Ernest Bade No Wrecks on This Railroad' 706 Home Movies Toys for a Merry Xmas 797 Inexpensive Home -MovieSets (:06 Novel Time and Money -Savers 798 Reflectors for Amateur Movie Maker; IsSpace Curved-- 800 nonaid A utomotive Lick Observatory, .111. Hamilton, Calif. Advances in Automobile Design in1930 778 How to Select an Oil Burner 801 By Waller P. Chrysler By Harry F. Tapp, Oil Burner Specialist Compressed Air Auto 791 Illuminated Table Decorations You Can Make 803 Motor Hints-Illustrated 802 By Josef W. Ion Stein Radio and Television Magic-A Monthly Feature 804 Opinions of Leaders in Radio and Television Developments 778 By "Dunninger" 820 806 Radio Gives Us Photos. Music and Television Inexpensive Home -Movie Sets Chicago Police Use Radio to Outwit Outlaws 822 By Don Bennett New Radio Sets 823 Making Silhouettes Without Scissors 807 Radio "Eve" to Guide Planes 824 By H. H. Duna How to House Airplane Cloth Speaker 824 Tricks With a Phonograph 809 Radio Oracle --Questions and Answers 825 By listen Moen First of New Series of Brain Teasers 811 How to Make It By Sam Loyd, the Pu=le King Illuminated Table Decorations You Can Make 803 What Our Readers Think 818 SCIENCE AND INVENTIONModel Trophy Cup 805 Scientific Humor 826 Making Silhouettes With Scissors 807 The Oracle 827 How to Build a Record -Winning Model Plane 808 Latest Patents R28 Hints for the Home Workshop-$10.00 MonthlyPrize... 812 Patent Advice 838 I low -to -Make -It 813 By Joseph II. Kraus Toy Railway Tunnels Easily Made 814 815 FinancialArticle 859 Making a Writing and Stationery Cabinet By Alfred .11.Caddell \Vrinkles and Recipes-$5.00 Monthly Prize 816 NEXT MONTH WITH OUR AUTHORS 1GCSTCS POST, author ofthe ar- ARRY F. TAPP, author of the arti- "\\'hatI " cies on Oil Burners for Home Fur- and LATER 'tideinthe presentissue naces. which are now appearinginthis F.,und On Board The R-101,"is known journal.is one of the best c7:perts on oil Highest Railroad in the World practically all over the world and he has burners that we have today. Mr. Tapp is associated so many years with the leading a collegebred man andhas made a By A. Hyatt \'errill aeronauticalpeople,thatthenameof specialized study of oil burners, with the The Future of Rocket Flying Post is practically a household word. Mr. result that he stands today at the top of By Prof. Robert H. Goddard, of "moon Post predicted in 1914 Colonel Lindbergh's his profession in that particular field, and flight from New York to Paris.lie also is the technologist or consulting engineer rocket" fame, and America's foremost spe- to the American Oil Burner Association. cialist in rocket propulsion drew up the rules for the prize won by lie is the author of the "Handbook of Do- Colonel Lindbergh and offered by Mr. Ray- mestic Oil Heating." 450 Miles to the Gallon! mond Orteig.Mr. Post has written numer- By Alfred M. Caddell ous aviation articles and is a popular lec- turer on aviation. GEORGE A. MI.:RS, who editsthe A New Solution of Our Traffic Motor Hints section every month, is a Problem consulting engineer of Washington, I).('.. DR.DONALD H. MENZEL, ofthe andhas doneconsiderableengineering Which Shall It Be-Dirigible or famousLick Observatorystaff,has work connected with the Arsenal at \Vasil- Airplane? been writing astronomical and physics ar- ington. ticlesfor a number of years, and heis By Augustus Post one of the foremost ofthe younger gen- Gliders-Another Article for the eration of astronomers in this country. Dr. DON BENNETT, who writes so inter- Menzel was previously connected with the estingly every month on Home Mov- Embryo Fliers ies, has had considerable experience in the Harvard AstronomicalObservatory,and motion picture field.As in many of other When "Ching Ling Foo" Got has made a special study of the Einstein branches of industrialactivity, he comes Fooled theory.Severalof his articles have ap- into the home movie realm with a back- pearedinthis magazine in the past few ground of extensive experience gained in By "Dunninger" months dealing with a popular interpreta- the regular theatrical motion picture Pumping Mud to Make Airports tion of some of the Einstein arguments. field, including every detail of the business.

VOL. XVII Whole Number 201 January, 1930, Number 9

SCIENCE AND INVENTION. Published 1879.Title registered at the U. S. Patent Office. Subscriptions:$2.50 per year in U. S. and monthly by Experimenter Publications, Inc., at Copyright, 1929, by Experimenter Publications, possessions;Canada andforeigncountries. .3.00a 18.1-10 JamaicaAve.,Jamaica,N.Y. En- Inc.The contents of this magazine must not year. Experimenter Publications,Inc. tered as second class matter, at the Post Office be reproduced without giving full credit to theExecutive andEditorialOffices,381 Fourth at Jamaica, N. Y., under the Act of March 3, publicat ion. Avenue, New York City, N. Y.

770 January, 1930 Science and Invention 771

The Old Way E LECTR !CITYBecomes Amazingly EasyWhen Taught qfflthout Burks orLeSSMIS Why work at dull, uninteresting jobs that will never pay you more than $35, $40 or perhaps $50 a week?NO EXPERIENCE or Advanced Make up your mind NOW and become a master of Education Necessary electricity! Train in 12 easy weeks to hold down theYou don't need one days' previous electrical experi- kind of a job that pays $60 and up a week, ence or advanced education to master electricity and which creates a constant demand for the Coyne way. Some of our most successful gradu- your services nearly any place in the world! INCLUDED ates never went farther than the 8th grade. If You Act Now: R. R. FARE No Books No Classes mill be refunded Earn While You Learn Electricity, as taught in the Great Shops of Coyne, upon enrollment By special arrangement, our employment depart- is surprisingly easy to grasp. That's because we fromany pointInthe ment helps students locate part-time work, if they 1U. S. to Chicago. use no books. You learn by doing actual, pradical AVIATION want to earn while they learn. And after_gradua- experimenting on big, electrical machinery-finest my bignew Aviation tion we give them the benefit of our FREE EM- outlay in the country. Yon learn by doing-and Electrical course in- PLOYMENT Service for Life.Every week we you learn from the ground up. cludedatno extra secure many positions for Coyne men. 2charge. RADIO Not a CORRESPONDENCE SCHOOL course included ab- Experts work right along with you every step of solutely without any the way. You get personal attention-you are trained 3extra charge. Get FREE BOOK AUTO Write today for my big book on Electricity with not by books but on actual electrical machinery. course. covering The COYNE WAY gives you real, sound knowl- truck and tractor over 150 photographs. Learn what great opportu- edge that fits you to do pradical electrical work 4electricity. nity Coyne Training opens up for you.Also get in all its branches. SEE COUPON! full details of my Big 3 -Special Offer. No obliga- Now in Our tion. Mail the coupon now. NEW HOME This is our new, fireproof, modern home wherein is installed thousands of dollars' worth of the newest and most FREE BOOK Coupon modern Electrical Equipment of FIN RIM all kinds. We have now the larg- IIIIII IN= MEI OM MI NM M= MEM MEM IMO est amount of floor space devotedIH. C. LEWIS, President to the exclusive teaching of prac- COYNE ELECTRICAL SCHOOL, Dept. 10-27 tical electricity in the world. Ev- 500 S. PaulinStreet, Chicago, Ill. ery comfort and convenience hasIPlease send me your free catalog on Electricity and details been arranged to make you happy Iof your railroad fare allowance and extra courses. No ob- and contented during your trainmg. ligation on my part. ELECTRICAL SCHOOLIName H. C. LEWIS,Pres.,Est. 1899 COYNE iAddress SOOS. Paulina St., Dept. 10.27,Chicago, III. I amolimignommailayiminuimwdmimeminiebanwalCity State 772 Science and Invention January, 1930

Holding Down theRTOI

IT takes quite a a -Tight to hold crown this mighty monarch of the skies.A mooring mast and four of these masske rollers, each one ticeighingaton, are barelysufficienttokeep the gigantic dirigible from roaming over the British Empire. The one -ton roller shov:n yitoings front the tail end of the R-101 as the huge airship is moored to the mast at Cardington, England. January, 1930 Science and Invention 773 Who else wants a good T

jobsforstudents! We haverecently develoed which a enablesplac envent serpvice MARI NG JIM positio us to find whenonly s for our good half students DURINCi the past few months we have placed HUNDREDS of former Way through making mechanics, clerks and even beginners in fine positions-with Contractor,. RAPID rnenare causethey Architects and in big manufacturing plants all over America (reada few are combiningbe- typical letters below). spare time sturogress ence on thedy withexperi- job ---and These men came to us because they were dissatisfied with their earnings and with their a that's beat! that future prospects. Now they are doing work they like --making good money-and harea real Mail can't becoupon, chance to athwart: still .farther. we'll tell the you all an new job-linding about thisd If you are trying to solve a similar personal problem, we invite you to get in touch withus. plan. We'll be glad to show you how you, too, can get a well -paid Drafting job without riskinga penny of your money. Electrical Wonderful Opportunities Jobs Open to DRAFTSMEN!We trained these men An easy way to break Into the great. prosperous.well- Pick up the want ads of any big city newspaper and you'll sec ed Electrical industry. is why we advise men to go into Drafting. 70,000 fine positions wen to learn Electrical Drafting. then PLACED THEM! Then the doors of oppor- advertised in the past year by Architects, Contractors, and in tunity in a line where the Electrical, Mechanical and Automotive lines. "Sky's the limit" are open to you. The ability to read blue -prints and draw plans is the entering wedge to success in all building and manufacturing industries. The work is mighty interesting and pleasant, the hoursare easy, Building and and Draftsmen are a wonderful bunch of fellows to work with. Construction JobsBest of all, Drafting offers you the chance to meet BIG MEN, the chance to take charge of big jobs, the kind of future you've M.itlYJr our st 11110131S in Architectural or always hoped for. StructuralDrafting,and their we help them get good Starts at .° ha,,, 11 Now Junior Jobs with Contractors or 11, kit Puta .o Draftsman Architects. A knowledge of $40 a Week Tel. and Tel. ( u. Promotion for Office and "Thanks for help-in Seattle, andI"I have obtained a Drafting is a pass -port to must say that lampositional, atonal, quirk success in the big ing me get a Draft-greatly i wielded building Industries. Factory Workers.... ing position withto the Americandraftsman with the School for my suc- al uneie O i I Engine Thousands of nten-not a bit smarter titan you, with no mere schooling or SlykerCo.startingcess. You have at $40 a week." done al I that youyouraid mobtttin- experience-have gone from poorly paid positions as clerks, mechanics. sales- promised in helo-mg this position men, building -trades workers, laborers and beginners-into Drafting posi- Oska- R. Ludwig,t ng me obtainvery much.' ' Automotive tions paying $10, $50 and up to $100 a week, with our help. Gary, Ind.employment. M. N. Barehant. r. C. White ftluncie. Ind. Jobs I want to show you that a good Drafting jolt is now easily within your reach. And I want to art before you our amazing plan of Home -training and place- Look tit notch the want -ads ment which we have worked out with the cooperation of some of the biggest NIERICAN SCHOOL, Dept. D-153 of any city where there are employers and engineers in America. automobilefactories and Drexel Ave. & 58th St., Chicago, Ill. you'll be surprised at the Please telltime, without cost or obligation, number of Draftsmen re- about your training and employment service quired. and the splendid in line marked X below. titularies paid. Many noted Great Chance for YOU automotive engineers and exerut has got into the work DRAFTING through Drafting. if You Act QUICK! Architecture Business M meat Ii ivLf Building Accounting non' We lutist' an interesting proposition for ambit it/US Ellen eager to Structural Stool Mechanical Engineering eel into Drafting. Itwill pay you to rush thecoupon tous byfirstmail. Civil Engineering Shop Superl PE.luertrEicnigtyineering Foremanship Mechanical High School in 2 years Jobs Any experience you have in meehardeal lines will be The American School of priceless benefit to you as a Draftsman. for then you know how things are Dept.D-153,Drexel Ave. and 58th St. State done on the Job. Drafting is PROMOTION for the me- It. iccupation chanic and apprentice. CHICAGO, ILLINOIS 774 Science and Invention January, 1930

0ETECTI OR

cikVAN NORTON MURDERS

THERE hale been so many detective novels published in the past few yearsthattofindone both exceedingly wellwritten and startlingly different is a distinct surprise. "The Van Norton Murders," by Charles Reed Jones, combines both these qualities in a swift -moving and refreshing pace.The author, you "Young Peter's may recall, also wrote "The King Murder," Dutton's Book of the Month beenshutinhis coos:. Theyhad for April, which called forth columns of praise from the nation's critics, to break the door because of its novel reasoning and unusual plot development. down to get into hint.Ile was dead when theygot In "The Van Norton Murders" the plot evolves around a wealthy Long there." Island family which is rapidly being killed off in spite of all the police can do.It seems evident thatitisn't an outside job, yet no trace of suspicion can be pinned on anyone in the whole household. One of the detectives in the story, however, tells you that he knows the murderer, and that you can figure it all out yourself if you have read the story carefully up to this point (and you actually can).You'll probably find that from the moment you turn the first page you will be so completely ens eloped in the problem before you that the wee early hours of the morning willstillfind you gripping the arms of your chair in tensed "1 know damn we!! fascination. he didn't shoot himself, becauseI never heard of a gay shooting him- AND THE COMPLETE PRICE IS ACTUALLY ONLY 25c selfintheback, but the door:vas Moreover, the publishers have gone and brought the novel within reach of locked." everybody by enabling you to buy it complete for only 25c at all newsstands. Simply ask your newsdealer for the January Complete Detective Novel. (There will be a new one at your newsstand every month.)If he is already sold out, send 25c in stamps or coin to

THE MACKINNON-FLY PUBLICATIONS, INC. 381 FOURTH AVENUE, NEW YORK, N. Y. January, 1930 ScienceandInvention 775

the40facyWays to Make $300anhour 'PHE four- I. plans InYour Spare Time Below shown are but a are a few of sample of the many ways in which our mem- the reports bers are making $3.00 an in IRAIDIC from those now hour upwards, spare time cashing in on the aid full time, from the day they join the Association. If you want to get "40 Easy Ways" into Radio, have a business of your or' - ClearsFrank J. Deutch, Pa.-"Since own, make $50 to $75 weekly in 53,000.00win joining the Association I have your spare time, investigate the ;4M .0417 cleared nearly $3,000.00.Itis almost impossible for a young fellow to fail, opportunities offered the inexper- no matter how little education he has, if he ienced, ambitious man by the As- REDUCE will follow your easy ways of making money." sociation. STATIC 1:5Y piARMOU 5WI \ $1,100.00 in J. R. Allen, Calif. - "Have done over $1,100.00 worth of Our Members Earning '4 D 0yfRY;4E61)1911g:4OP 6 Weeksbusiness in the last 6 weeks. Next month I am going to open up a store Thousands of Dollars of my own. I never knew that money could Every Week come so fast and easy." The Association assists men to $25.00 a Week N. J. Friedrich, N. Y.-"I cash in on Radio. It makes past ex- Spare Time hpoarveLvelraasf week perience unnecessary. As a member months$25.00aeven of the Association you are trained though I am not a graduate but just learning." in a quick, easy, practical way to Training Lands R. C. Kirk. N. C. -"Your install, service, repair, build and training has been very IMPRO Him Job valuable to me. I landed a rebuild sets-given sure-fire money- vow b job with the big department store out here a making plans developed by us- few weeks ago because I had my member- helped to secure a position by our +or. ship card with me. There were a large bunch Employment Department. You earn tr, of applications ahead of me." while you learn, while you prepare ycurself for a big -pay Radio position. The Association will enable you to ACT NOW buy parts at wholesale, start in busi- If You Wish NO -COST ness without capital, help you get Membership your share of the $600,000,000 spent annually for Radio. As a result of For a limited time we will give to the Association, men all over the the ambitious man a No -Cost Mem- comtry are opening stores, increas- bership which need not-should not ing their pay, pass- -cost you a cent. For the sake of inglicensed operator making more money now, and

examinations, land- having a better position in the ing big -pay posi- future, mail coupon below now. aikob3.-F;,_ELECTMFy tions with Radio rTiONOGRAPH3 You'll always be glad you did. makers. -- Radio Training Association of America Mail Coupon Today for the Dept. RN -1, 4513 Ravenswood Ave.. Chicago, III. Gentlemen: Please send me by return mail full details of FREE HANDBOOK your Special No -Cost Membership Plan, and alsoacopy It is not only chock-full of absorbing of your Radio Handbook. information about Radio, but it shows you how easily you can increase your Name income in your spare time. Mailing the coupon can mean $50 to $75 a week more for you. Radio Training Association of America 1id re s 4513 Ravenswood Avenue Dept. RN -1, Chicago, Illinois at), State .ei JANUARY. 1930 VOLUME XVII NUMBER 9 WHOLE NO. 201

Arthur H. kynch, EDITORIAL DIRECTOR

H. WINFIELD SECOR, E.E. JOSEPH H. KRAUS T. O'CONOR SLOANE, Ph.D. Managing Editor Field Editor Associate Editor ALFRED M. CADDELL AUGUSTUS POST WILLIAM F. CROSBY Financial Editor Aviation Editor Marine Editor Editorial

... THE PRACTICABILITY OF LARGE there may be some justification for this idea, but DIRIGIBLES. There are two schools of thought for the most part we believe thatrather long in the aircraft field in the matter of volume trans- trips across country will be much more comfort- portation.Many of the greatest students of aero- able when accompanied by music to suit our mood. dynamics are very firmly convinced that the air- This extremely interestingfield opens up many ship of the future must be of the lighter -than -air new lines of development and offers those inter- class. The making of lighter -than -air craft of ested in radio technique an opportunity to inves- extremely large size presupposes the use of in- tigate electrical fields again in somewhat the same terior supporting members.This is very well il- fashion that the public took generally to the intro- lustrated in such dirigibles as the R-101, which duction of the regular broadcast receiver.Itis is fully described in this number ofSCIENCE AND very likely that the home constructor will have INVENTION. another very interesting day. The other school of thought is firmly convinced * * * that the airship of the future capable of carrying ... CITIES OF TOMORROW. Our cities are the greatest pay load economically will he some becoming too congested.The congestion is rapidly development of the airplane.The possibilities of reducing the efficiency of trade which fosters the the heavier-than-air craft were brought home very grouping ofbusinessinterests. Citiesofthe vividly when the DO -X, representing the largest future will, for a few years, at least, get much of 'plane built to date, recently took to the air with their architecture from such men as Le Corbusier, 169 passengers and crew.This flight, of course, whose interesting article appears in this number. was only for an hour's duration and consequently Suppose, and it is easy to suppose, that we find that not much of the weight taken into the air was it becomes so difficult to get around town by auto represented by fuel. On the other hand, it is to be thatit becomes necessary to pull down all our noted that the Graf Zeppelin, powered by 2,550 present buildings and have beautiful cities of tall horsepower, as against 6,000 for the DO -N, has buildings and green fields.Airplanes flittingin a useful load capacity of 140,000 pounds.Trans- and out among the skyscrapers are bound to be lated into the number of human beings this ship is an ordinary part of urban life twenty years from capable of lifting, figured on the basis of 150 now. pounds per person, the dirigible could take ap- ... SUPPOSE-There is just one fly in the oint- proximately 933 people aloft.To date, the great- ment.Suppose a plane or two, heavily laden with est number of people ever transported in a dirigi- bombs, come dropping them at the base of a few bleis82.but the distance covered, which in- buildings.General William Mitchell says an army volves many tons offuel,has been thousands and a navy are useless against such an attack. of miles. * * * Factors of speed, ground facilities and so forth ... MUSIC FOR THE MASSES. There is no must also be reckoned in the heavier as against more refining influence than the influence of music the lighter -than -air analysis. With the cruising and poetry.Scientific efforts are now being made speed of the DO -X approximately double that of to provide music of the highest order in our the- the present-day dirigible and with considerably less atres, schools and even in our homes. Some delay hangar space and ground crew necessary the plane in the progress has been caused by groups of mu- type of craft possesses many attractive advantages. sicians who feel that the radio, the talking movies. However, the entire subject is well worth thor- and other similar mechanical devices will do them ough investigation and the superdirigible now be- out of a livelihood. We feel that this is a short- ingbuilt by the UnitedStates Navy and the sighted view to take, and believe that when Amer- superhangar which is already under way to house ica becomes completely music -wise, there will be it are introducing engineering problems which but a broader rather than a narrower opportunity for a few years ago would have appeared to be com- the truly good musician.Much development work pletely insoluble. An interested world watches this stillremains tohe done before the mechanical competition. * * reproducers of music reach perfection. but improvement is so rapid that a "talkie" ill any of our .. . RADIO FOR YOUR CAR.Our contem- country towns is superior to one of the old road porary, Radio Arews, is sponsoring a campaign to cut,,'.vs. popularize the use of radio receiversill automobiles. The ideais being received with acclaim generally, but there are some who believe that we already have enough noise and that the use of radio receivers may also increase thetraffic hazard. In some of our more congested areas

"Those Who Refuse to Go Beyond Fact Rarely Get as Far as Fa, - 111,ALEY

776 January, 1930 Science and Invention

Pledge to the Public on Used Car Sales

Every used car is conspicuously narked 1s% ithits lowest price in plain figures, and that price, just as the price of our new cars, is rigidly maintained. 2All Studebaker automobiles which are sold as CERTIFIED CARS have been properly reconditioned, and carry a 30 -day guarantee for replacement of defective parts and free service on ad. justments. Every purchaser of a used car may drive it for five days, and then, if not satisfied for any reason, turn it back and apply the money paid as a credit on the purchase of any other car in stock -new or used.(Itis assumed that the car has not been damaged in the meantime.)

/Ng C.,petarion of Aene.. Youcan save money and getabetter motorcar -if you buy according to the STUDEBAKER PLEDGE PLAN Over 150,000 thrifty American citizens did last year

AWELL constructed car, sold at 4o or so per cent of its original price, offers maximum transportation value. Studebaker dealers offer many fine used cars-Studebakers, Erskines and other makes-which have been driven only a few thousand miles. ¶ Reconditioning of mechanical parts, refinishing of bodies give new car life to these cars at prices no greater than you must pay for a cheap new car. And as a final measure of protection, these cars are sold according to the Studebaker Pledge -which offers s days' driving trial Invest 2c-you may save $200 on all cars and a 3o -day guarantee on all certified cars. ¶ Prices Mail the coupon below for !low the free booklet.The ac being plainly marked provides the same price for everyone. to judge a used stamp is an investment Millions of people buy "used" houses. Every car on the road carz which may save you as is a used car the week after it is purchased. much as szoo in buying a motor car!

THE STUDEBAKER CORPORATION (IF ANIERICA Dept. 175, South Bend, Indiana STUDEBAKER Please send me copy of "How to Judge a Used Car"

Builder of Champions 'Varna'

Street

City State 778 Science and Invention January, 1930 oilatTamous Men A Symposium of Opinions

arises we will find new methods Ilookforfurther of using the light, or some new method of directing it.I look refinements in the syn- for further refinements in the chronization oflight, synchronization of light, move- movement and sound ment and sound during the year 1930, but nothinginaddition in the theatre.- seems indicated for the speak- Belasco. ing stage. Dr. Ales Hrdlicka ll'alter P. Chrysler. welbknown motor cw manufacturer and one of the out- Sees Advances in standing geniusesinautomobile design. Evolution er HE probableprogressin I our knowledge of human Walter P. Chrysler evolution, and of evolution Predicts Many Im- in nature in general, during 1930, will he.it may be anticipated, provements in Cars essentiallythat of a gradual GREATER flexibility, longer life, superior performance and increased Blank & Stoller quietness will he among the ma- Harveyit Corbett,well-known jor improvements on automo- architect and desigrer of skyscrapers. biles for the coming season. Greater flexibility will he achieved very largely throughHarvey Wiley Cor- the use of the multi -speed gear- box, putting an extra speed in bett, Famous Amer- the hands of the driver when he ican Architect, needs it.The use of four in- Looks Ahead Plicto E. Aline stead of three speeds will enable Da: id Belasco, Dean of the American the experienced drivertogetPr HE probableadvancein Theatrical Producers and Master of more nut of his car than is pos- I architecturein1930that Mechanical Stagecraft. sible with three speeds, because wouldbeofinterestto hewillbe abletoacceleratereaders of.S.cienre and Inven- up -hill. travel faster on the leveltion will be an increasing de-David Belasco Dis- roads and in every way be pre-velopmentinthe use ofsky- cusses Stage Mech- pared to meet existing road andscraper buildingsfor business, grade conditions with a gearhotel and apartment purposes. anisms considerably in advance of whatTXVENTIONS for the thea- hasbeeninthepast. The tre invariably come through 0 Barbratli presentgeneration is air - Motor cars will fol- necessity.Often they meet Dr. Ales 17rdlieka,U. S. National minded and buildings will emergencies. A need arises and Museum, Washington, D. C., pr,m- showgreaterflexibility, low that trend. someone improvises something inent exponent of human evolution. longerlife,superior Inthematterofarchitec-which will care forit. Ifit tural styles, -itis well to note performance andin- thatarchtrologicalstyles so works, then thatis made thefurther crystallization of ideas creased quietness.- consistently used during the basisforthenextinventivein thisfield, together with the Chrysler. last thirty years. arc very rap- step.Consequently it is difficult accretion of additional detailed idly disappearing.Both archi- to predict what 1930 will bringfacts, bearing on the subject and tects and their clients see littleus in stage inventicin. broughtoutthroughexperi- reason why an individual in this Personally,Ican promisemental and other studies. ratio thatisideally suited forrapidly moving twentieth cen-some new lighting effects, based There is always the possibil- those conditions.For this sametury should he housed, either inon my other inventions of theity of startling, highly impor- reason, proper driving will behis home or office, in a settinglast fifty years-but again theytant discoveries of new material made immeasurably easierfor inspired by theMiddle Ageswill be effects demanded by the inthe line of man, the other the inexperienced driver. and the Renaissance. atmosphere of new plays; againprimates, or the rest of the or- Better carburetion, largely se- they will he an improvisation toganic realm, but judging by the cured through the down -draft meet a sudden requirement. pastitis more probable that method, will increase flexibility Stage mechanism has reachedtherewillhe but moderately stillfurther by always placing Buildings will he nearlyitspeak of perfection.important finds which, neverthe- at the disposal of the motorist built with a fastening Lights,too,arestandardized. less,individuallyoronthe sufficientfuel, properly mixed, largelythroughinventionsin whole, will not fail to add to tomeet the demands ofthe together of parts pre- my own experimentallabora-the solid paving of which the driver's foot on the accelerator viously manufactured tory.There has been developedbasis of the science of evolution pedal.Backed up by fuel pump in the factory.- the lightI have sought all ofis being constructed.The most feedinstead of vacuum, with Corbett. my life-reflected, diffused andhopeful localities for discoveries the mixture flowing downward capableofcarryingcolor-ain the human line, and in that with gravity instead of against light without center of illumina-of the anthropoid ancestry, will it, the motor will be responsive, tionandequalin intensitybe western and southern Europe. regardless of the condition of New methods of constrwionthroughout its area. Palestine and Asia Minorin the vacuuminthemanifold. will undoubtedly come into gen- Even my electrical technician,general, and Africa. This is a real improvement. eraluse-methods more con-Mr. Hartmann, andI do not In writings there will prob- Longer life will be securedsistent with machine production.know as yet what developmentsably continue a development in through the elimination of vi-Buildings, in my opinion. willmay grow from this, except to theLamarckianratherthan (Scccontinuations on page MI) (Continued) be assured that when the needDeVriesian direction. January, 1930 Science and Invention 72., Predict for Sciencein 1930 of Leadersin Art, Science and Industry

Radio Advances En- Prof. Robert H. God- visioned by Wil- The Pacific will he dard, Rocket Flight 1930 will show in- liam Dubilier crossedintheair creased patronage of without a stop and the Expert, Gives His passenger air lines on THERE willbe no great world circumnavi- Predictions the part of the public, changesduringtheyear 1930,for the industry has gated by refueled IDOUBT ifmuch willbe as a necessary adjunct been taught that a great change flight.-Post. donewithrocketautomo- in conducting modern will do more harm than good. biles in 1930, but 1 look for business.-"Casey" Improvements and develop- more flights with rocket planes. ments willcontinue, however, In both cases, however, powder Jones. withthepublicgettingthe Augustus Post Seesrockets will probably continue benefitofgreatervaluefor to be used, and long distances money spent. New Thrill in Dir- will therefore not be attained. igible Races This is because powder rockets. "Casey" Jones Sees even when equippedwit h THEimmediate future will nozzles, have toolittle energy Greater Use of Radio setswill be I see 100 -ton air liners andfor long flights. Planes by Public air lines and routes of com- The very fact that bundles of soldincombination mercial transport planes greatlypowder rockets, having rather the with talking moving extended,connectingtheone obvious limitations, have txenUNQUESTIONABLYmost interesting develop- pictures for the home. thousand projected airportsin used on planes has,Ibelieve, ments in 1929 in aviation all parts of this country with which will be reflected in pro- -Dubilier. thoseinallquartersofthe duction in 1930. will result from globe.While speed is the first various types of airplanes which great factor in air travel. lux- America isnot yet arenow beingassembledat ury, comfort, safety and free- Regarding radiosets,these fully alive to the pos- Mitchell Field to compete in the dom from dust and dirtare Guggenheim willbesimplified, a smaller sibilities of the rocket. SafetyCompeti- number of tubes will be used to equallyimportant. Unsightly, tion.NVIiile at the late of this crowded conditions on monoto- give the volume required.Ra- -Goddard. article itis too early to predict nous earthly routes must give just what the results willbe, waytothebroad,inspiring there arc an extremely interest- bird's-eye view that makes air ing prejudiced American engineers number ofmachinesen- travel such a joy. teredinthecompetition, and Mechanicallandingdevices against the rocket plane.What should he realized, however, is theresults on the matter of for airships and more efficient quid: climb.controllabilityat dockingfacilitiesmustsoon that with the entirely new and different system of rocket pro- low speeds, slow landing speed. come,inresponse tothede- and abilitytogetinto small mand bothfor use by globe- pulsion with liquid propellants, which I have developed, and in fields, are -bound to result from which the proportion . offeel this competition. to total weight is made large, The autogiro is being success- a rocket plane should receive fully developed in this country a much larger and several concerns have ac- porportion ofcepted licenses to manufacture the energy content of the fuel these. thanispossible with the or- Again itis too early to dinary airplane. In other predict what the final results of thisdevelopmentwillbebut words,theefficiencyshould present indications point to in- exceed that of the latter. creased safety and popularity. The year 1929 has shown an increased volume ofairmail and with the adjustments in existing contracts, which may (Continued)

Dubilier, radio pioneer and in: odorofapparatusbearinghis name. dio sets will be sold in combination with talking moving pictures for ,he home, as the radio equipment is not only capable sPost. 'Hertel, IIaeronau- ofsupply'ng entertainment re- t authority, who predicted (Wane! ceivedfrom broadcastingsta- Lindbergh's New l'ork-to-Pars fright. tions. but is adaptable for sup- plyingthe soundfor movingcircling"Leviathans"ofthe pictures.The large proportion sky, as well as the "iron pigs," of the sets for next year will "flyingashcans"and"pony Robert11. Godda,a,Professor of Physics, Clark University, ll'orcestcr, have provisions for phonograph blimps," as the small metal and Mass. reproduction andfor home fabricdirigiblesarejokingly movies, at acost within the called. Whentheexcellent reachofthemasses. With features of the reliable dirigible Actualoperativeflightsof screen -grid tubes and simplified balloon arefullyrealized, weliquid -propellant rickets of the Photo Cuitir Flying Service components, four or five vacuum aresuretohavenotonlytype necessary for long-distance C. S. (Ca

BOW LOOK -OUT cPthat MOORING VENTILATORS EYES.

'PASSENGER SHEAR ENTRANCE LONGITUDINAL -711. WIRES C.:. 7GAV7"' `BAG RADIAL. GIRDERS

ok oot man

einfoiced Bow

MooringEye

Window The world's largest dir- I-.awse Pipe igible, the R-101, measures

11 Side Mooring 732 feet long by 132 feet in t - - Guys diameter.The maximum Emergency Water Ballast Bag speed is 70 miles an hour; -Gang plank closed Prome- payload52passengers; :rade deck Gang plank open and corner2600 engine horsepower. of lounge. ON the morning of October 14th thousands of people in Lon- ELLON: don were enthralled by the GLASS/ sight of the R-101, which made its first flight over the houses of Parlia- ment with an escort of small airplanes. The traffic of the city ceased in a measure and the rumbleofthe motors was distinctly heard by the ear of London, as its eye had been quickly made aware of its presence in the sky. The state ship "R-101," whose trials are taking place at the Royal Airship Works at Cardington, Bedfordshire, England,isthe largest airship yet completed in the world.Originally designed to carry 100 passengers and with accommodations for that number, with the present engines she can only take 52.This reduction was due to the decision to eliminate gasoline as NON - the main source of power in favor of SHATTERING cheaper fuel oil, which gives virtual GLASS immunity fromriskoffire. The change involved producing a Diesel January, 1930 Science and Invention 61 I FoundonBoard the 8101 By Augustus Post

This 7011.0

for.Ses, o, and THE author of this article. Mr. Augustus Post, whose .11 genial likeness you see in the photo at the right. recently returned from England. a here he had a chance 11, inspect the R-101. hich has recently made a number of successful flights in England.Mr. Post is one of the best- known lecturers and writers on aeronauticalmattersin America, and he has had the interesting experience of having witnessed the first airplane flights by the Wright brothers at Fort Myer, Virginia. a quarter ofa century ago.Mr. Past flew at Hammondsport, New York. in1910, and in various air meets at other places.He was aide to Alan R. Hawley. winner of the Gordon Ben- nett Balloon Race in 1910, having flown a distance of 1172 miles. Mr. Post drew up the rules in 1919 for the New York to Paris flight for which Mr. Raymond Orteigofferedtheprize won by ColonelCharlesLind- bergh.In 1914 Augustus Post prophesied atrans -oceanic flight, which was later ful- " filled byCOlonel Lind- At PASSENGERS hergh. CABINS \\\\. PROMENADE

WINDOWS RUDDER .k' ELEVATOR MIDSHIP R/01 OTOR GONDOLA AFT L-ATOR

AFT The R-101 is MOTOR GONDOLA propelledby --0- Diesel oilen- gines. There are Upper leek: 1, gas bag; 2, lounge; 3, promenade; 4. win- five engines, dows; 5, stain -rise;6, dining -room; 7, dumb -waiter; 8, each develo pi n tYPe 411 engilic. of WCight low balancing tanks; 9, lower deck; 10, cabins; 11, gangway about 5;0 horse- enough for use in the air. The from bow. power. fact that the 01is the first airship to dispense with gaso- lineis an important stepin ;:VAPEAv97022;4VP, progress. The framework of the air- Voraloit,40,1w." ship is of much larger cross- t4loto4V " section than the corresponding 14, 000°."0-0 part of the Graf Zeppe/in, as vte,...", itisdesignedtowithstand strong rising air currents such 6-e#,r. as may he found in tropical countries. %%here theyeven range as high as 45 miles per hour. The passengerrooms are spacious and comfortable and are made chiefly of light wood.tltiraluminninand aluminum. Thechairsand furniture are extremely light. although they present the ap- parent solidity of the furnishings of an ocean liner. ((ontinued on page 840) 78 Science and Invention January, 1930

The photograph at the left shoats New York's Health Com- missionerIf' ynne studying the (hart of the sunlight recorder in the offiee of the National Conference Board onSanitation, as picked up bythe photo -electricc ell illustrated below.

iimuir UMW= Soot Costs Taxpayers $96,000,- 000 a Year, So New York City Is Now Battling Smoke Nuisance

THE Department of Health of New York and New York City are waging war on the smoke bination of anelectrical nuisance whichnotonlyisdetrimentalto resistance and a light-sen- health and vegetation but also costs the taxpayers of sitive(photo -electrical) New York City about $96,000,000 a year, or an aver- cell, together with a source age of $20.00 for every person in the city.The Health of suitable current supply. Department is combining a campaign of education and oneThe photo -electric cell re- of war against careless offenders.It has been definitely acts to the slightest change determined that most smoke and the resulting soot and dirt in light intensity.Such a is caused by careless or inexperienced firemen or else faulty change is duly recorded by the potentiometer (electrical bal- Inrnaces.All of these conditions can be remedied. ancing resistance) recorder.Photographs show smoke pour- It has further been discovered that New York City re-ing from the funnel of a vessel in the Hudson River, and the ceives only three-quarters of the sunshine that pours downothers show Dr. Shirley W. Wynne, Health Commissioner upon it; the other quarter is blotted out by smoke.In the of New York, examining the apparatus.This sensitive in- winter time as much as one-half the sunshine is cut off fromstrument has proven the fact that life for the city dweller is the city because of this same condition. not as healthful as it possibly might be.New York, fortu- An actual check on the sunshine isnately, is one city where the soot and smoke effect has been made by an instrument known as the minimized. foritis not a great industrial city like Pitts- "daylight recorder."This is a com-burgh, where the smoke on a cloudy day is very noticeable. .---qiiii- z."----

REVOLVING FIXITIF APPLIED ARM HERE ECHO PEN

-4N MAGNET. 7 SOUND PRODUCER

HULL

\I SOUND N k-HYDROPItONE `\ PRODUCER / (MOUNTED IN \I "r BOTTOM OF ACETYLENE 1161110,4 SHIP) 11111111111111.1611111111 GAS. How Smoke Records Ocean Depths ROVE Nye reproducediagrainatically the way in which band.On the chart the first nick recorded indicates sound oneof our modern vessels, the lie de France, makes sent out; the lower nicks indicate reception of "echoes."If records of the depth of the water through which it passes.two seconds' time ensiles between sending out sound and A sound is sent out by a sound producer.This is reflected receiving echo, bottom is 4.000 it.deep, as sound travels from the bottom of the ocean and picked up by a hydrophone4,000 ft. per second in eater and had to travel down and mounted in the bottom of the ship.At the moment that thereturn up.Underneath the paper band is a steady, smoke - sound is produced a record is made on a blackened paper producing flame.The flame is fed by acetylene gas. January, 1930 Science and Invention Around the Worldin 17 Hours LEAVES NEW YOQK top AT 4.a.m. Cephenemyia, Fastest Thins in Air AER1vES SACK N.Y. 9p m. SANE DAv. IMAGINE an insect thatflies 850 extreme speed. But the few experi- miles per hour; that can be seen Tr- ments performed with the specimens ob- only as a blur when passing; that tainable have proven that its speed as can fly long distances without stopping; quoted above is true.If only this tre- that could leave New York at 4 A. M., mendous speed could be obtained by a and, after flying around the world, ar- man-made machine, think of the great "C--1.-13 N1N t rive back in New York the same night advance in rapidity of transportation. 4MADRAD at 9 o'clock; these are the possible ac- For instance, if an airplane could attain complishments of the fly known as the the tremendous speed of 850 miles per Ccphencinyia, according to Dr. Charles hour. one could leave New York City :".nooTp, POLE Townsend in an article published in The at 4 A. M.. have breakfast at Reno, stop Scientific Monthly. Thisflyis very off at Peking for lunch at noontime, take WO PLC. rare. and only a few specimens ofit tea in Constantinople. dine in Madrid, have been procured on account of its and he back in New York at 9 P. M. The Schneider Cup Races showed that aviation is still in its infancy. The Schneider Cup Races recently showed that a plane could acquire the speed of 3 6 3 m.p.t. 365 m.p.h. with some degree of safety SAIAAR KANO and we have it from the famous expert, .4/cove is diagram of the seventeen -4011r 'round -the -world flight.Dotted line shows Louis Bleriot, that according to a graph approximate path of plane. of speed increases in motors since the .it the upper left is a picture of the fly genus Cephenemyia. It is about the size of a bumblebee and three times as fast as an airplane. beginning of aviation the speed of 750 in.p.11should soon be realized. Plane and Radio Speed Whaling T N these (lays of scientific achievement Moby 1 Dick would have no chance to chew off a man's leg and then beat it away. The good old whaling days 01 near -starvation and cruising for two or three months without sight of the big mountains of blubber are gone.First it was the power har- poon. steam -driven boats. and now airplane and radio.This newest wrinkle in the line of whale - hunting has been used by some Norwegian whalers in an expedition into the Arctic.The plane is equipped with a 220 -horsepower motor, pontoons and skis, and with afull load of gasoline can remain in the air thirty hours.Its method is to fly short distances away from the whaling vessel, and on sighting a whale, the plane communicates with the ship by radio.The ship then races to the scene and proceeds to make the kill.This is dem- onstratol graphically in the sketch at the right. Take Movies of Yourself Camera, showing tube THE greatest problem in taking pic- and bulb attachment tures of the family has always been to for remote operation. get everyone in the picture.That was almost impossible because someone bad to hold the camera.Usually a neighbor would consent to do so. but when one ownsanexpensivemovie -camerahe doesn't like anyone else to play with it. That problem has been solved by a well- known manufacturer of home cinema machines. They have attached a long rubber tube with an air bulb at the end of it. On pressing this bulb, the camera starts, and, presto! the movie is taken.. This new device is something to add to the usefulness of the camera.It enables one to take pictures which otherwise might not be obtainable. Forinstance. Camera mounted on in movies of tripod shows how nature study. one might place the camera simply this may be op- at a certain point and keep out of sight of erated to get everyone the anim:d and still get his pictures. And, in the picture. as shown on the left,itis invaluable in photographieg the family group. Science and Invention January, 1930 Curycr ill tort' * 7110.,tril'4"311:,;I! --:-I !/,,,Nsigem.

Le Corbusier, France's Great Ideal Future City of 3,000,000 tralized Traffic, Great By H. Winfield Secor Associate Member,AmericanInstituteElectrical Engineers. WI IAT \ vill the city of tomorrow be like? This question is a difficult one to an- sxx er, ascityplanningexpertswill readily agree, but one of the most excellent schemes worked out for the design of a future city is that of M. Le Corbusier, the French architectural genius.In this remarkable plan fur the city of the future, not only is the arrangement of the business section of the city, with its towering super -skyscrapers, considered, but also the equally important problem of where the peo- 01;sb,7.` ple shall live and how. January, 1930 Science and Invention 785

Architectural Prophet, Visions With Super -Skyscrapers, Cen - Parks and Airdromes M. Le Corbusier has planned his idealistic city to have a population of 3.000,000. As the illustrations show, he provides a concentrated busi ness section at the center of the greater city, an here towering super -skyscrapers house the office workers during the day.As will be noticed, then skyscrapers are of a radically new design and 6( floors arc virtually flooded with air andlight. owing to the corrugated shape ofthewalls. which are supplied with plenty of windowsAir- craft may land on the roofs of theskyscrapers as well as on those of other buildings, and inthe central business section there isa large, unified traffic terminal or station.This station has a great, circular airdrome or landingplatform of (Turn the page) 786 science and Invention January,1930 Future City Plans Promise Traffic Relief Better Light large area for planes and dirigibles.Be- low this platform there are other levels. reached by communicating stairways and elevators, where high-speed automobile traffic from north to south and east to west passes through the street level inter- section.Below this one finds himself on the station platforms of the high-speed railroad system.Suburban sections are wellservedwithtrainsoperating on loops. M LE CORBUSIER'S dream of the future city is one of the most comprehensive plans ever proposed, tak- inginto consideration asit does the handling oftraffic, improved dwellingsforthe workers, as-yellassuper - NEW YORK CITY Wall ITS HIGOLY CONGESTED SKYSCRAPER DISTRICT office buildings and airdromes The photo above shows lower New York City with its great mass of skyscrapers. right in the city. Note that about 60 per cent of the ground area is covered with buildings and only a few per cent devoted to grass and trees, so greatly needed to purify the air.

One of the main arguments for this design of city is that and grass would provide a very healthy and delightful liv- while we may have a highly concentrated population in the ing section.Large lakes and woodland would be found in business section or center of the great city of tomorrow. the intervening protected zones, between the central part of traffic, especially with regard to automobiles and trains, should the city and the garden cities. be simplified.In this most comprehensive and promising W'ith regard to the super -skyscrapers of the type here plan of Le Corbusier's, the matter of caring for the traffic proposed. examination of the typical floor plan as shown in would seem to he well worked out.It is only a matter of one of the accompanying pictures, reveals the fact that the having the principal arteries of traffic made large enough to buildings are designed in the form of a cross, thus doing take care of a great many automobiles or trains.In other away with an internal court and giving maximum stability to words, this genius' idea is to have a few large arteries of the structure.The facades are deeply serrated and form traffic separated a much greater distance than is the present veritable traps for light.The capacity of one of these super - plan in practically all of our cities today. skyscrapers 460 feet long and 700 feet high is 30,000 em- Among the many practical details which are presented in ployes. allowing 10 square yards per person; while one of Le Corbusier's plan for the city of tomorrow h; has given these skyscrapers 540 feet long would have a capacity of careful study to the health and welfare of the population. 40.000 people. Long roads of compact garages, multiple Instead of covering, say 50 to 60 per cent or more of the floors of which may be placed underground with elevators area of the city's ground with buildings, with a few trees in or ramps. are to be found on the ground level, and these small parks spaced half a mile or inure apart, he has designed garages are placed in the angles between the wings of the skyscrapers and residential buildings of a type which only skyscrapers.All motor -car traffic is gyratory. A peculiar occupy about 5 per cent of the ground area. leaving 95 per sight strikes one's eyes on the ground level as the skyscrap- cent of the ground for trees, grass, lakes, etc.People need ers are not walled in, but one sees the numerous steel col- pure air, even in the city, i f they are to be thoroughly healthy umns which carry the sixty stories.This leaves open space and accomplish their work properly. One of the accompany- for freight storage. etc.The elevator and stairway shafts ing pictures shows in how great proportion the park (or are enclosed, but the frames are open.It is a fact not often tree and grass) area in a city like New York would be realized perhaps that if ene took away the outer foundation increased if M. Le Corbusier's plan were applied instead of wall from under one of our present-day skyscrapers, the the present one, where one can sec nothing but buildings skyscraper would still be safely supported by the steel and studding practically the whole ground area, when viewed concrete piles underneath it. which go down to a solid footing. from an airplane. M. Le Corbusier, in one of the chapters on "a typical The general plan of the great future city mil its environs working day" in the future city. as given in his remarkable calls for a centralized business section, where the skyscrap- new work. The City of Tomorrow,* says: "It is 9 A. M. ers are surrounded by a considerable number of residential "From itsfour vomitories, each 250 yards%vide,the blocks, liberally interspersed with parks.The main boule- station disgorges the travelers from the suburbs. The vardscarrying motortrafficwould Just publkhed by Payson and Clark, Ltd., of Nrw York City. then lead across intervening countryPlan of theCity of ( protected zones) to so-called "gardenTomorrow centralized railroad system as vis- cities." where plenty of green treesualizedbyLeCor- busier.T h e business and manufacturing centers are localized; the people may live in cellular type dwellings adjacent tothebusi- ness section or in the suburban garden cities served by the railroad loops. Picture at right -one of the plans for housing the people in dwellings built on the "cellular" system. Note the large park area. January, 1930 Science and Invention 787 More Parks_CentralkedRail Terminal RoofAirports a new paradox.Since New York City (Manhattan) is to some extentan ab- sur(Uty, the whole ideais vehemently attacked.The truthisthat the skyscraper, as we have itin New York. will not do, for by means of it New York has increased its density to too great an extent, without proper pro- visionforthe necessary approaches. New York City is wrong, but the sky- scraperremainsanobleinstrument. But if you are going to increase the density of your population.you must at

plan here presented THEfor the City of Tomorrow calls for a population of 3,900,000, but it can been- larged to any desired scale. The skyscrapers of improved type giving more light and air are about 450 feet across AsNEW YORK WOULD LOOK WITH LE: CORBUSIER'S PLAN IN EFFECT and 700 feet high.All traf- Lower New York as Le Corbusier would lay it out, with buildings occupying about fic lines are centralized. 5 per cent of the ground area, the rest being devoted to air -purifying parks.

trains, running in one direction only, follow one another at the same time make fullprovision forgetting-itaway. one -minuteintervals.(InBerlinatthe'Zoo'station,There are two sides of a medal ; one cannot exist without where many lines meet, this masterpiece of precision has the other....In a few moments the city fills up.Work been in operation for years.)The station square is so enor-begins and, speeded up by efficient organization,goes on mous that everybody can make straight to his work withoutbusily in luminous and even radiant offices whose immense crowding or difficulty. windows open full on the sky and the lofty horizon, where "Underground the tube taps the suburban lines at various the air is pure and noise far distant. points and discharges its passengers into the basements of the working clay may finish after midday. the skyscrapers, which gradually till up.Every skyscraper The city will empty as though by a deep breath.Thegarden is a tube station. cities will play their full part.And, on the other hand, in "A skyscraper is, in fact, a whole district, but verticalized! the city itself the residential quarters will offernew living Ten thousand to fifty thousand employespass their day in it,conditions to these new men ofa mechanical age." each with a minimum superficial area of tensquare yards to Thus does the prophetic French architect paint work in. the picture The original and primitive conception of the sky-of a business day in the city of tomorrow.Doubtless we scraper comes to us from America; but if the disposition ofshall also have new forms of heat and light whenthe com- these shown in my scheme is compared withan aerial pho- ing generation takes office.Radio telephones will be found tograph of New York, where the skyscraper completely in all offices and automobiles will be drivenby some new holds up Manhattan, it will be seen how great is thecontrast form of fuel, possibly by electricwaves. between the latter and a rational and clear conception where As some of the accompanying illustrations indicate,the a large outlook has been the deciding factor in the relation residential angle of the future city has been carefully studied to each other of these indispensable elements. In New York and one of the main underlying ideas is to provideresiden- City 20,000 people invade a narrow street at practicallyone tial apartments arranged in long winding strips.one type of moment, and the result is complete chaos; all fast traffic iswhich M. Le Corbusier callsblocks ofdwellingswith set- paralyzed and the idea for which the skyscraperstands is backs.Another suggested style of residence he calls dwell- robbed of all significance. Created for thepurpose of decon- ings built on the cellular system;the height of the building gestion, actually it slows up all traffic and is, in fact,a powerful factor for congestion. for example in the cellular plan is 110 feet above theground. The result is that peoplecryThe "building" is made so narrow that plenty of freshair out against the skyscraper and the vertically builtcity, andand sunlight flood the rooms at practically all times.Fur- because of the need to get about quickly,oppose the type of thermore, practically 9a per cent of the ground city which is spread out over a very large area can be area.So we havedevoted to lakes, green grass and ( Coninued on page834)

The picture at the left shows aclose-upof blocks of dwellings built on the "cellular" system proposed by 1., Corbusier. The build- ingsare tenstories high. Planatright shows street crossings for fast auto traffic in futurecity. All traffic is gyratory. 788 Science and Invention January, 1930 Would You Believe It? Photographic Proof of Facts Stranger Than Fiction A Real "Shrinking" Man cer HEY tell me Icould live 50 years -a- with the malady.ItI do, and I continue at my present rate of shrinkage, 1 could hide behind a shoe box atthat timer'Joseph Mayon, World and Spanish-Ameri- can war veteran, and one of thestrangestcases known tomedicalscience, is sufferingfrom Look Out for This Monster Tank! what istermed 'THIS monster, latest type of armored tank, Paget's disease.Ile is as harmless as a flea on a wet dog.It's has lost nine inche: made of 135 pounds of SOAP!It measures 5.5 in stature in the past meters in length and is 3.5 meters high.This eight years-a little example of careful workmanship was recently more than an inch exhibited in Berlin at the Soap Exposition. ayear-andtoday The above metric measurement, trans- he is 4 feet 10 inches latedinto terms of the English system instead ofhisnor- of measurement. would give this tank a mal 5 feet 7 incite,. length of about 18 feet and an approximate Over400 doctors height ofII V,feet. Since an average have examined him cake of soap weighs about three ounces. and agree that May- this destroyer of dirt makes enough soap ott's condition need for over 700 families. not necessarily prove fatal. and he could live 50 years more! This Melon Grew in This Bottle CAPTAIN JohnA.Gilman,ofthe Quartermaster Corps at Washington, explains to visitors. who have vainly en- deavored to solve how this melongrewinafive - gallonbottle,that hemerelyinserted thevineproducing the bud in the bottle when the fruit was aboutthesizeof an olive.

A Miniature Giant of the Sea "Columbus- scale midel, shown beside a model of the old "Santa Nlaria," is T"Eequipped with gas engine drive.The model cost $4,000.Note head of operator and boy on deck. A "Roller Coaster" Bridge gracefully curved $6,000,000 Bridge over the Cooper River. South Carolina. 1 -msalthough higher than the Brooklyn Bridge in one part, sweeps to within 50 feet of the water at another point. C II! may The "Queerest" Elevator visit Meteora Monastery in Thes- IFsaly, you willhave to go up inthe basket you see in the picture unless you prefer to climb doubtful looking ladders. Ever so.itis a long way up to the spot where you get the basket.This isthe refuge for which the Meteora group of seven were named.Monks of the Greek Church builtthese refuges as a protection against mountain bandits. January, 1930 Science and Invention 7S9

.1 bore diagram shows various places, from merica to Europe, where itis proposed to anchor the scadromes.

Edwal ifrmstrn g and/L sradrome MID -OCEAN model. AIRCRAFT STATIONS .It left is shown portion of sea - draw which projects into sea. Below, diagrammatic view of RECENT experimentswiththeseadromein- seadrome is : el vented by Edward Armstrong, consulting engineer. have shown that such man-made land- i:1sstations for trans -oceanic air travel are quite prat:- LANDING PLA tcal. In Chesapeake Bay. a model 1/32 of the full size has been subjected to cross -currents. wind, waves. and choppy seas. and has weathered every test.The model used was 35 feet long. 11feet high. 10;4 feet wide. and weighed 2200 pounds.The fullsize seadrome -oon to be constructed and anchored between New WAVES BRtAN AND PASS \ork and Bermuda will be 32 times larger.It will ACrwl ID survotts providelargehangars,andstorehouses,landing space for planes, as xvell as a hotel for the travelers. it will have the enormous draft of 172 feet: this will eliminate all pitching and tossing due to large waves. It will rise 92 feet above the level of the water. and he suitably marked for identification by the airplane pilots.It is planned to install eight across the Atlantic. MORE and BETTER LIGHTS Safeguard Life and Propertyon LAND and SEA

The new: optical sys- Lighted Arrows Show tem of the Royal Direction of Liners Dutch liner "Ba- tavier 1." consists of three illuminated ar- r o w sconspicuously placed on the bridge of the ship, as shown at right.This will iR replace the old systemof steam whis- tles for signaling directions.

France Lights' the Way to Better Traffic Direction The quaintlittle town ofSt. Denis, France, has recently inaugurated what is regarded as the tallest traffic towel in existence. Four searchlights, eighty feet above the ground, project in each direction. Half -way up thetower arebrilliantlights which illuminate the square. 790 Science and Invention January, 1930

Autos Cross Mountains on Trains MOTORISTS are now enabled to conquer the Sierra Nevada range in midwinter.By the special service between Sacramento. California, and Reno, Nevada, they can check their cars in this baggage car at a!,out 10 cents a mile.

tIneSpotlight Flashes from far corners Electric Flashlights for Taking Photos R. L. F. CURTISS. a physicist Steel Tubes Make Fine Scaffolds .LJ of the U. S. Bureau of Stand- ilSCAFFOLDTUBE," steel tubular scaffolding used on ards, is shown with his electric flash- this church tower, permits an open construction, due to its great strength.This method offers lower resistance to wind pressure and a much less unsightly effect results.Insert shows this method used during the redecoration of the Town Hall of Birmingham, England.The hall was used during the entire Nvork of renovation, the tubes being painted to match the decorations and being scarcely noticeable.

Corn Stalks Turned Into Gas HOUSEHOLD wastesandcorn stalks,ordinarilylefttodecay, can now be utilized to provide a gaseous mixture of carbon dioxide and methane or marsh gas. This gas has a heat value nearly equaltothat of gas supplied cities and can be used to run a generator to charge storage batteries thus supplying farms with electric light and power. The apparatus converting corn stalks and wastes into gas was used in experi- lightfortakinginstantaneous ments by Professor A. M. Buswell of photogra phs.This mercury the University of Illinois and his as- spark gap is especially suitable for exceptionally fast sistant. Mr. C. S. Boruff. -shots."Danger from mercury vapor is eliminated by sealing the arc.The spark gap consists of a pyrex gla-s tube containing mercury. with a heating coil around it. An Automobile for the "White -Collar" Worker rr I IESE two photos show a new folding automobile recently tested in Ber- lin. Germany. The price and practicability of this vehicle places itinthe reach ofall classes. Itcosts about $350 and can be readily dissembled for storage when garages are un- available. The inventor. Heinrich Zaschka of Berlin.isshown in the photos. 1930 Science and Invention 791

Self -Playing Violin Has Real Technique THIS violinista, recently shown in New York, is controlled by perforated paper rolls.It uses a standard bow entirely free at its points and held only at its heel.

cl of cience of the world's stage

Compressed Air Auto TRIALS were recently marle at Essen. Germany. by the Cierman inventor. Max Valier. who is known for his experiments with a rocket -propelled automobile.This new type of...al-utilizes compressed air.The car runs quite noiselessly. and it is claimed that the danger associated with rocket-pripelled cars is eliminated.The photo shows Max Valier demonstrating- his car before an enthusiastic amlienee. The cylimlers containing tile complessed air can beseen.

"Electric Matches" Meet Mr. Rumbler, Who "Chews" Glass for Texas ABARRELFUL of old incandescent lamp, call be poured Oil Fields into this machine which. with crashing and popping noises, threshes the glass off the brass bases.The New York PrIi E electric Edison Company uses this machine to salvage this brass. 1 "matchbox.' The machine will smash about 300.000 burned -out lampsa shown inthis year.Formerly lamps were broken by hand. They were put photo hasre- into a churn -like barrel and the op- placed matches on erator worked a dasher up and oilfieldsinthe down. a comparatively slow method. Beaumont section of Texas.In or- How Quick Do Athletes der to reduce pos- sibletire hazard. Answer Gun? workers are for- 74111Selectrical tinier, which bidden to carry was recentlytestedinthe matches on their mid -West, shows the time it re- person. Ifowever, quires a personto to give eniployes physicallyreactto an opportunity the sound of a start- for smoking. the ing gun.The firing companies erected of the gun is instant- a number of these lyrecorded on a electric lighters graph and the onisolatedsec- elapsed time before tions of the fields. the foot leaves aThe lighters are ground -contact isprotected%43 that alsothenrecorded. thecurrentwill Races are often won not injure the by "beating the gun." user. 791 Science and Invention January, 1930 Tandem Monoplane THIS two -motored tandem monoplane was recently tested at Roose- velt Field, New York.The plane is claimed to be non-stallable, and the tricycle landing gear, clearly shown in this photo, prevents turnovers when making a bad landing.

Newest Ilde Greater Safety in the Air Is Gathered from the Flying Moving Wing Stops Stalls W. SCOTTER, at the International Inventions Exhibi- MR.tion, Central Hall. Westminster,England, with his moving wing plane, which he claims will not stall, and can ascend and descend in a small area. Land Planes kept Afloat

Photo at left shows dis- abled land plane safe afloat by automatically inflated bags. Seaplane "Drydock" for Open Water THIS special pontoon is especially adaptable for towing planes from small inlets into rough, open water, where they can be safely launched.It can also serve as an emergency drydock when repairs must be T HE U. S. Navy has adopted made or it can be used as a mooring nest -L a"flotation gear"tokeep when the water becomes exceptionally rough. bombers afloat when forced to Thislanding pontoon wasfirstusedat descend in the water.Barrel - Calshot, England. shaped gas -proof bags are nor- mally foldedin compartments in the body. A lever alongside the pilot controls the valve of a gas container, which automatically opens the compartments, ejects and fills the bags in about ten seconds.-J. W. VS.

Fuselage Always Level THIS unique craft is a monoplane, with the fuselage swung about six feet below the wings by means of six streamlined Fins and Flippers for Flyers struts, as shown in the photo. The motor is situated on the wing. By means of a giant universal joint behind the motor, the fuse- VERTICAL fins under upper wing preventside -slips, and lage with cockpit will ride level at all times, regardless of whether flippers in front control fore-and-aft stability.This inven- the craftistaking off or landing.The inventor, Rolla V. tion of Dr. C. N. Vance of Pomona, California, successfully Norris, of Porterville, California, is seen in the cockpit of his underwent a rigid test flight at the Los Angeles Field. machine. January, 1930 Science and Invention 7'13

Family "Flivvair" THIS folding plane, designed byCol. Clarence Chamberlain, measures only 10 feet 1w 25 feet with wings folded hick.It should appeal with its flying speed of 135 miles per hour. III Aviati the Keynote of Recent Inventions Fields, by our Aero Editor Airship of the Future? STATIClift of the dirigible combined with the dynamic lilt of airplanewings,willmakethisstrangecraftthe"Air Leviathan" of thefuture,itis claimed byitsinventor, John Hodgdon of Long Beach, California.Presence of the oings will prevent rolling and pitching common generally with blimps, and it will also be possible to land with motors running, without the aid of a ground crew.

Baby Airships AFEW of the large European advertisers are turning to baby blimps to advertise their product.The message is painted on the sides.

Radio Interference Stopped Wheel Shock Absorbers THE shields, Nvhich may be seen on the motor in the illustration, THEGoodyear "air wheels" take the place of shock absorbers. serve to prevent the setting up of waves which would ordin- I- Air resistance is reduced by streamlining this combined wheel arily interfere with radio inter -communication. and shock absorber. O :4 2

k k 4

/2.000 9.000 6.000 3. 000 Longest Lighted Airway in the World THIS air -mail express and passenger route, covering about landing fields are found every twenty miles, a revolving 24 -inch 2,00(i miles is virtually a lighted air boulevard. Emergency beacon every ten miles, and flashing blinkers each three miles. 794 Science and Invention January, 1930 Henry Ford's Museum Will House Edison's Early Shop for FutureGenerations

per cent and others are 90 per ago. The whole program was cent genuine. carried throughout the world by The old pedal organ, on which.radio, and millions of listeners Edison gained his knowledge of joined in this great tribute to one the principles of sound. is found of America's great men. Two fea- hereinitsfinalrestingplace. tures of this programwere the Here also is the chemical labora- speakingofPresidentHoover tory in which Edison worked. On from Dearborn and the congratu- the shelves are his original chemi- latory speech of Albert Einstein.

Fig.1. Hereisthe old pedal organ used by Edisoninexperimenting with sound. IFTY. years ago the world was ,tartled by the invention of a young genius of America.The fact that man had created a light which was smokeless, flameless. and sootless was hard to realize. It was even harder to realize when the inventor was revealed as a modest young man, Thomas A. Edison, with a very meagre and limited laboratory.His only work- shops were a few modest little shacks in the small suburban town of Menlo Park, New Jersey.His knowledge of the principles of physics and chemistry was almost as meagre as his laboratories, but he triumphed in spite of

Fig.2. Shows the various shelves of chemical reagentsof Edison with the original labels still intact.

Fig.4. The Wizard of Menlo Park evacuated the first incandescent bulb with this vacuum pump.

cal reagent bottles with their ancient labels intact. And then there is the old mercury vacuum pump with which Edison evacuated his first successful incandescent lamp.Here also is the Fig. 3.This is the original laboratory which. old shack in which Edison made some Edison used for his glass-blowing tests. of his first glass-blowing tests.Be- sides these there are many other relics of the inventor's youthful work in these obstacles.Today, a half century New Jersey. later, another celebrated American, Henry This museum was opened with a Ford, has paid Thomas Edison a great great celebration by Ford on October compliment.Mr. Ford has reconstructed 21st. A list of 800 guests, headed by this same laboratory, these same rooms. the most prominent men in every field and the same apparatus which gave birth of endeavor in the country, attended to this great invention, in his museum at the party.Edison met these men at Dearborn.No expense has been spared Detroit and with Mr. Ford they en- and no pains have been too great to re- trained for Dearborn, where Edison construct the entire setting in its original performed many of the experiments he form.Mr. Ford has even brought soil had originally done many years ago. from Menlo Park. and all the buildings He exhausted a lamp, set up a circuit Above is another view in the famous are reproduced faithfully; some are 70 and lit the bulb as he did fifty years first laboratory of Edison. Januat y, 1930 Science and Invention 71'5

Above shoes general 'view of humidifyina furnace. Made -to -Order Weather for Your Home ANEW furnace, operated by gas. has recently been designed by a prominent thermal engineer to regulate the relative humidity of the home as well as the heat temperature.It is a well-known experience that the pan of dl'ove view shows how air is brought in through incoming dudAvater placed on top of a stove or radiator does very little to ".1," drawn through filters "B" by rotary blower "C" (operated I y exterior motor "D"), forced through laws interchanger "E," efficiently counteract that annoying dryness of the mucous into humidifier "F," into mixing chamber "II" and into house. "M" membrane in the nose.And that may not surprise anyone thermostat, "N" excess brat control."P" it the pilot governing if he knows that it takes twelve gallons of water per day to the gas flame.Escape of gas, fumes, or carbonis provided keep the relative humidity of a six -room house normal. This through backdiaft d:vertrr "K" and flue "L." furnace is well designed and is suited exactly for the small house owner.The technical details are simple:the air is drawn in by a duct and the dust removed by fine wire -meshed screens. A centrifugal blower now carries the air into the A Quarter Million Volts heating chamber, and after being heated by gas. it is passed through a humidifier: the heated air is then blown through Al the left is conveying pipes to the different rooms. shown a giant Oudin coil, one of the spectacles at the re- Space -Saving Radiator cent Radio ANEW radiator of compact design and desirable effi- World's Fair in ciency has recently been introduced. New York. This It consists of a coil was operat- number of copper plates secured to the steam pipe, which ed from an or- runs lengthwise about five inches from the floor.As shown dinary 110 a.c. in the accompanying drawings, the radiator is compact and 60 -cycle circuit. By means of a transformer, together with suitable spark gap a n d condenser, the voltage was stepped up to 250,000 and produced a spark about two feet long.Although the coilis surrounded by a steel cage,itis almost absolute- lyharmless, as the extremely high frequency ofthecurrent makes it impos- may be covered very easily with the wire cage, so that it does sible to cause not interefere with the scheme of the room. As copper is a injury.How- very efficient radiator of heat, when welded to the steam pipe ever,ascreen it distributes the heat very quickly, and thus insures maxi- cage was used. mum efficiency. 796 Science and Invention January, 1930 oWrecks on This Railroad WESTINGHOUSE engineers recently demonstrated a new automatic railway device at the recent Canadian National Exposition at Toronto. Canada. A miniature railway with trains which stopped. started. and switched without human aid or interference was demonstrated as a suggestion of the railway of the future.The entire manner of control is centered in a panel of relays, time element relay, meters. and a circuit -breaker.There is also included a load regulator to keep the train speed constant ;if one train stops, more current is available for the other. Each train automatically stopsallow it to cross, while a red light. flash- Above is the miniature railway showing and starts at the station. and while it ing in the opposite direction, willstop control board and track lay -out, with trains remains at a standstill the other is auto-the other oncoming train until the first crossing in path of each other. matically switched around the station to one passes.The track is laid out ina a different route.As the train ap-block system; so that if the train follow- proaches a cr,- - lug. a green light will and gain, it is automatically stopped to ing the first one should increase speedavoid cellision and rear -end crashes. What Boy Chemists DidHave You EDWIN ISRAELS, 18. and William Chtlnow.s-ky.19, are shown here experimenting with microscopic slides Heard in the home-made laboratory which they built. togolierwith three other boys, in the backyard of the Israel hone, Middle This One? Here's Some- thing New in Phonographs ANEW model phonograph featuring a new de- parture ill automatic record - changing has been pttt On the market by the Capehart Company.in some models ther...pro- clueing is augment- ed bythree -stage amplificationa n d dynamic speaker, which makts it feasible for out- door entertainment. The records are en- closedin cabinets on eitherside of theturntableand lifted by means of arms to the turn- table and the tone - arm is lowered-all automatically. The main advantage of this instru- mit melt seems to be itsadaptabilityto any problem where phonographs are to be used. The instrument is supplied with loud speaker built in cabinet or with external speaker, and this makes itsuse possible for both home and theatre.It is also interesting from the commercial Village. New York.The boys, all of high-school age, use point of view, for it may be adapted to coin -box control, awl this twelve -by -fifteen -foot shack for their experimenting, thus solves the problem of musical entertainment for the and have tackled many current problems of science in this small confectionery shop -owner or for the proprietor ofthe crude workshop, mostly in biology and chemistry. small dance hall.It reprodnces very well. January, 1930 Science and Invention 797 Airport Construction Set Complete flying fields-with hangars, mooringmasts, landing - fieldlights, revolving beacons and searchlightsoperated by hand -cranks, to say nothing of Zeppelins, U.S. Navy airships and blimps as well as monoplanes, biplanes, amphibiansand seaplanes. remain!,in style from the "Spirit of St. Louis"to Tractor huge four -motored transports-can be constructedfrom metal This midget, but power- aircraft construction sets. ful, spring -operated tractor will irresistibly push ;isway over steepob- staclesduetoallfour rubber -studded whee Is beingconnectedtothe "power plant." The trac- torisprovided qcitha brake and a special de- vi,e for producing a slow. steadymotion. Itwill climb over mountains of books.

Machine Gun Ti,e bullets are fed by gravity from a magazine.Rapidity of fire depends upon the individual. Electrical Crane This toy, powerful enough to lift any toy engine or car, is controlled by two gear- shiftlevers,start -stop -reverse,double clutch and worm gear.

7'he Graf Zeppelin This scale model, propelled by a large, clock- Miniature Anti -Aircraft Gun work operated propeller at the rear, makes cir- Thisrealisticmodelshootsrubber cular flight when suspended by a string. pellets propelled by the explosion of small paper caps.It is elevated and revolved for Automatic Diving Submarine directional sighting by hand wheels. r

Self -Playing Sax There's no need of practice to play this instrument, which operates by means of special paper music rolls turned by a hand- This clockwork -operatedsubmarine crank, the air being produced will automatically dive at regular in- by "lung power." tervals. Diving planes are adjustable. Motorboat A small pellet of solid alcohol will keep this boat going for an hour. Room Equipment Miniature rooms, twoof whichareillustrated,are completely equipped with metal household furnishings. (Nantes of manufacturersfurnished on request) January, 1930 7' Science and Invention Novel Time and

Powerful Midget Binocular and Sport Glass THIS photograph shows a new sport glass and alongside of it a midget binocular being held in the hand of its owner.The latter glass is five power. can be carried in the vest pocket and weighs only five ounces.It contains 10 lenses and 4 prisms.Being made of Photo eourte,y 31Irakel 0Ulk I Cu. a new composition.itspriceiscon- for its enormous field of view. which Vegetable Slicer siderably lower than that of a metal is equivalent to that of the unaided eye. TO slice vegetables with this article binocular.Itis greatly in demand byWere it not that everything appears to a rapidly moving disk with knivesexplorers where a good light glass isbe closer, one would little realize that is rotated by turning the handle.Vege- required. The small sport glass is notedhe were looking through a glass. tables arc inserted into a suitable hop- per, as the photo shows.The article may be clampedtothetable.- 111achine to Toast Buns J. IV. V. S. Preventing Dampness in the Food Cabinet DAMPNESS, thatdistress- ingfactorthat causessugarand salttocake and destroys the crisp- nessofcrackers, canbeeliminated by using a can containing a chemical which has affinity for water.T h i s product alsopre- vents rusting of BUN sandwiches have always been impular al c,untry tools in a cabinet. fairs and seaside resorts.Then along came the toasted sandwich and detracted somewhat from the bun sandwich CombinationVacuum Cleaner, Blower and in point of popularity.Not to be outdone, an enterprising Sprayer American manufacturer decided that as long as the public blower liked toasted sandwiches and buns, he would build a machine Pr HIS articleis a portable vacuum cleaner and to toast the bun. We here see theresult of his efforts.This 1 that can be carried in the hand.It comes equipped with that are inter- mechanism consumes only 375 watts, hence can be plugged regular suction attachments and with nozzles It changeable on either the suction or the blowerside.An into anyoutletsocket. velocity of air toasts from 5 to It) buns or oversize motor drives the blower and gives a 8 slices of bread in 45 sec- of 286 feet per second.This air can be used for blowing the dust from line onds. shafts, machinery, electricmotors and generators, or can be used in a Cork Screw paint sprayer at- With Levers tachment. "THIS cork 1 screw is quite unique in thatit can be made to exertapullon Cap Lifter the cork of more Pri HIS milk bottle cap lifter than 200 pounds. 1 is so constructed that when The screw portion itis applied to the top of the isfirstinserted cap. a tongue enters the paste- into the cork, then board covering.By pressing the bottle grasped the lever down. the paper cap and the handle is isautomaticallylifted,and gentlypulled. when itis again released, the This causes a ring cap automatically closes.The to tighten around device can be easily transferred the neck of the from onebottletoanother. bottle. pushing the The illustrations show this cap bottle (loxx nward- in both positions. namely the lywhileatthe closed and open position.Milk same lilac the cork is being poured from the bottle. screw is lifted.- with cap in the latter position. . 1'. S. Names and addressesof manufacturers furnished upon. request.) January, 1930 Science and Invention 799 Money Savers

AutomaticSiphonSep- Shadowless arates Cream from Light Milk DENTISTS Pr HE automatic siphon here and surgeons 1 shown, when plunged into a have found that a bottle of milk. immediately (lraws new light, the in- off the cream and then stops ventionofDr. operating.Airisconfinedin Leon Lazar,fills the lower portion of the tube. a long -feltneed and thisairrises.lifting any for proper illumi- fluid which has en- nationwithout tered the notch and shadows. Three causes the siphon to concentratedfila- start. The siphon mentlampsare automatically s t o p contained in three as soon as the pre- separate projectors which arc mounted in a suitable holder. determined depth of By manipulating but one handle, the beams of lightcan the liquid bas been be focused or directed through gears tocover a spot of reaclied.-1 ..-1.Bran- any diameter.The angle of tiltis also adjusted by this don. single handle.For dental work, color filters aid in match- ing shades of teeth and por- celain fillings. Ice Retainer Pr HE interesting article shown at the right is so made that it can he inserted into the mouth of a pitcher.The hvo sections arc pressed together and then released.The spring handle pushes them apart and causes the rubber -covered feet to grip the sides of the confining vessel. Ice and fruit pits are prevented from being poured into the glass. Ball for Cooking Rice RICE, when cooked. hould be soft and fluffy. but this result is not always obtained 1w thehousewife. The rice frequently burns or sticks to the pot.I I cooked in the aluminum rice ball illustrated at the left. sticking is prevented. The riceisthenfluffy Cigarette Extinguisher and Ash Receiver and soft throu !tout When cooking is completed. the ball is lifted out of the pot Pr LIE unique and due to the perforations. the rice drains quickly.The I combination catch is then unfastened. the halves of the ball separated, cigarette extin- and the rice is ready to serve. --1. 11.1'. S. guisher and ash receiver here illus- A Pin in a Second trated can be used Do you everfind on automobiles or that you need a onairplanesto pin in a hurry? With greatadvantage. thisdevice you just As willbeob- press down on the top served. inthecutaway and presto-a pin ap- photo,theitemonthe pears through a little right contains water in a hole in the top. head well.When the cigarette up and ready for use. is touched to the top of 'ibis holder comes in the extinguishing well. a a varietyofcolor sufficient amount of mois- combinations and will tureistherepresentto hold 200 pins at one put out the light.After time. The construc- this, the cigarette can be dropped into the second well, which tionissoarranged serves as an ash receiver.To fill up the water -containing that but one pin can portion, the entire object is removed and held beneath the be ejected. and there surface. The top is then pumped up and down several times. isnopossibilityof completely filling this part of the device.Because of the jamming. --J. III. V. S. small apertures in the top. the water evaporates slowly. 8()() Science and Invention January, 1930 SP ACE, TIME an d RELATIVITY Light travels in a long curve.There is no better measuring rod than light rays, but IsSpace we cannot tnake these behave according to Euclidean standards. We develop a theory from a postulate that CURVED? cannot be proved. Nowhere in nature By Donald H. Menzel, Ph.D. Fig. 5.The star, which ap- can we find a straight pears to be at .4is actually Lick Observatory, Mount Hamilton, Calif. located at B. line

The Trialogue Continued Through a given point only one line can be drawn. parallel to a given line . . LAYMAN-Perhaps you xvill be good enough to explain R.-That's enough for a start.How do you know that \vhat you mean by curved space. only one line can be drawn, as you say, parallel to a given PH a sictsT-That phrase has bothered me. too. How line?( Figure 1.)

Fig.1. That parallel postulate! Fig.4. .1light rayisnot a .actually, two lines are never par- straightline,but is fullof I( allel,owing todifferentcurva- waves. tures at infinity.

can space, which is nothing, have any curvature? L.-Come to think of it, those statements are really postu- RELATIVIST-I am glad you asked that question, since I lates. We assume them. intended to discuss it with you today. R.-\\"hy do you assume them? In the first place.I do not entirely L.-Because they are obviously cor- agree with you that space is nothing- rect. at least in the sense employed by rela- R.-1 f they are obvious. why do you tivists. We arc concerned, not with notprove themoutright :otherwise truly empty space. but with space that isbeingmeasured-inotherwords, ?9

Fig. 6.Owing to the bending of the light ray. the fish, Fig. S. Columbus could have said, actually at B. appears to be "There is a definite limit to the size Fig. 2.Three triangles drawn at A. of a circle that can be drawn on the on the earth's curved surface. earth'ssurface." No circleexists The sum of the angles is obvi- beyond that circle. ously greater than 180 degrees.

space that contains some sort of measuring rod-ayard- your system of geometry may be open toquestion? stick or a light beam, for example. When I speak of curved L.-If I recall correctly. no one has ever been able to space, I am. a little more accurately, referring to the curva- prove them-but they seem so obviousthat proof is really ture of my measuring rod. unnecessary. P.-Aren't you getting a hit metaphysical ?Why not take R.-Does it not strike you as rather queer that something the trouble to provide a perfectly straight measuring rod? so "obvious" cannot be proved?The greatest mathemati- R.-You forget that itis impossible to define a straight cians of all times have devoted their efforts to the problem, line. Our problem is not the exploration of space with without success.Riemann and Minkowski. the most illustri- hypothetical Euclidean (i. e., straight) measuring rods, but ous of these geometers. finally came tothe conclusion that those postulates are entirely unnecessary to the development Assume them to be true and you obtain your THE FL AT" SUR.FACE of geometry. Fig. 3..1 flat surface is made up familiar Euclidean geometry.Reject them and your geome- of many atoms, indicated as cir- trywillbe very changed- cles. Even the flattestpossible traight lines swing into long area is pitted with the spaces be- (Continued on page 852) tween the atoms. Fig. 9.The actual state of af- how do actual rods behave when they are used to survey fairs. The statement that the The ques- 96th circle is the largest that can space.There is nothing metaphysical about that. be drawn in our universe no tion is eminently a practical one. We should not try to fit more implies a sharp boundary any given type of geometry to the world, but determine what to space that the statement that is the natural geometry that governs it.By the way, what the equator is the greatest circle do you,recall of your geometry? that can be drawn on the earth L.-I've forgotten most of mine, Ifear.Let's see.A implies an end tothe earth's straight line is the shortest distance between two points. surface. January, 1930 Science and Invention 801 By Harry F. Tapp Oil Burner Specialist, Technologist, VENT'. BOILER% The American Oil Burner Association FILL THE purpose of an oil burner is, primarily, to permit liquid fuel to he burned in a furnace, originally designed for coal or some other fuel, and is really an accessory to the heating plant.Therefore, itis important that serious consideration be given to the entire heating system.It makes no difference whether it is a steam, vapor. hot water or warm air system; as long as it is well designed and in good condition an oil burner can be satisfactorily applied.But, if your present heating plant is not giving satisfaction, if some room is not heating properly,or any otherills of a sick heating system are *parent, the oil burner cannot be expected to eliminate them.It is true. some improvement is usually experienced, but itis not a OIL TANK-'. VALVE "cure-all." 275 GAL. LINE Above is shown an economical way of installing the oil It is for this reason, high class oil heating dealers have tank in the (Mar; approved by the Fire Underwriters. aheating engineer ontheir staff and make a survey of every heating plant before they fire from the side, or even the make the installation.When back of the boiler.If neces- theengineerinspectsyour HowtoSelect sary, the furnace can be turned home, give him all the infor- to meet your requirements. mation you have freely. Where In the past there has been the difficultyis due to some considerable confusion in con- minor fault he willlocateit anOil Burner nection with the designation of and,ifpossible,suggesta various grades of oilfuel by remedy. Ifthefaultisa The Average Cost of Oil -Burners, Size the use of their gravity num- major one. he will recommend ofOilTank, and Other Important ber and various trade names against making theinstalla- Advice such as Furnace oil, domestic tion until the necessary fuel oil, a light oil and heavy changes are made. oil. This confusion has been In an old heating plant the greatly eliminated by the recent adoption of uni- boiler or furnace will often be formoilspecificationsof the AmericanOil COMBUSTION either obsolete or worn out, , HEARTH Burner Association awl the Commercial Stand- necessitatingitsbeingre- RING ard Unit of the U. S. Bureau of Standards, placed. Inthiscase,itis which classi fy the grades by numbers 1,2.3. 4. recommended that a boiler 5 and 6-number 1 oil being a light volatile fuel, especiallydesignedfor oil number 2 a medium grade and number 3 a heavy burning beused,asitwill grade.These three oils are all comparatively prove considerably more effi- lightwhencompared with the oils number 4. 5 cient and economical than one and 6, which are used in large commercial and designed for solid fuel.In a industrial oil burning installations. warm -airsystem,awelded There are all kinds of claims made by various s'teel furnace is more desirable salesmen as to the advantages and disadvantages tlian the usual cast-ironsec- of the various grades.As a matter of fact, they tional type.Itis also recom- can allbe used with entirely satisfactory re- mended that a circulating fan sultsifthe equipmentiscorrectly designed. beinstalledinthecoldair The lighter oil (number 1) has less BTU's or duct asitprovides positive MOTOR' heat per gallon than the heavy oil (number 3) circulation of the warm air, Here is a rotary oil burner othever- but the difference is so small that the most im- resulting inmoreuniform tical type utilizing the atomizing prin- portant factor is the price.A burner designed temperaturethroughoutthe ciple for feeding theoil. for a number 3 oil may also use oils number 2 house, and itwill usually in- or number 1. creasetheefficiencyofthe Today, with the large number of fuel oil dis- system with a resulting saving in fuel. tributors, it is possible to obtain suitable oils in nearly every Another point to keep in mind is the basement.In part section of the country.An important development in this II, of this series, suggestions were made as to the possible respect is the conversion of coal dealers to fuel dealers.It uses for this part of the home.While itis not important is. however. well to make a check on the available grades of that you make all your planned improvements at once, itis oil in your immediate vicinity. well to give this matter some thought before the installation is made.For example:If the furnace room is small and you desire to install a What Size Storage Tank? laundry, itis possible GAS ATOMIZING PILOT CUP that an inside type of TT is important to decide upon the size of storage tank burner would be de- when making up your plans for the installation ofa sirable as this type of burner.If your house is small and regular oil deliveries -='-- burnerrequiresless e assured, a basement tank of 275 gallon capacity makes ji _..mr.,.1.-- floor space.If, on thea very desirable installation and at the same time reduces

Nil ii I other hand, you preferthe installation cost.In some localitiesitis permissible FriRE .ti the other type of to install two 275 gallon tanks in the basement. 11 GAS -. Vii:P!,..BRICK H burner, it may be pos- This type of installation gives adequate storage capacity ::SUPPLY iiiiNC.3 7.:;- ' MOTOR VI, sibletekiinstallitto for almost any residence.Where this type of installation ILOAT ilt left U shown a cross - is not permitted and where oil deliveries are likely to be OIL SUPPLYtsection of the atomiza- slow, the underground storage tank should be installed. R r r.,ERvOl ', lionoilburner in the The usual size of underground storage tanks is1100 vertical position. gallons capacity, althotutli many I.Contimted on page 832) S,.ience and Invention January, 1930

By Motor Hints George A. Luers

DIRECTION /CAR WHEEL WHEEL TURNS --*-21--,1/4 -CHAIN

WASHER

' TRACTION BOARD ;HOOK CHAIN-.

BEVELED AND CONCAVE OAK - BOARD 2'-0" LONG, Illustration shows r car in settled po- X 8" WIDE sition in rut.At X1/2" TH. right, use of board to lift car. SLOT

How to Get Out of Deep Mud orHow to Plug Holes with Babbitt disagreeable process, is illustrated here. Snow A metal disc, made quickly from a lift the rear wheels of your can lid, or a large washer with a hole TO MOLTEN to tit over the nozzle end of the gun is car from a ditch, the illustrated DAM OF ,- BABBITT wooden lifts will prove an invalu- SAND AND all that is required for better operation. able aid. Two are required. The hoards CLAY Place this down against the grease, should be of oak, about 1Y4 by 8 inches press the gun into the opening and. and 2 feet long. A notch is made at one while pulling back the plunger. continue RECESS IN to keep the disc pressed into the grease. end to accommodate a chain; the other SAND TO FORM end is made concave and beveled to pro- A HEAD TO The gun will be full in a single stroke vide an easy start for the wheel.Two RIVET. without air in the barrel.The lid of pieces of chain, one for each wheel, are the grease tin can be trimmed down and used, with a hook on one end and a a hole can be made in it for this use. washer on the other.The chain slips free from the board as the wheel rolls off it. AFTER POURING, Overcoming Defects of Four - THE BABBITT IS Wheel Brakes Test for Lost Compression BEATEN SOLIDLY INTO THE HOLE FRAME SHAPE OF HANGER SECTION 1 TIRE GAUGE OF CAR. ,CAUSING INTERFERENCE THROUGH ,,..--- SPARK PLUG SHELL '4(tD e.) Using babbitt metal in plugging aluminum. VALVE AND rr HE use of babbitt metal, as shown -- PISTON HANGER AFTER BEND - LEAKAGE 1 above,isverysatisfactory. The ARE SHOWN hole in the casting is placed above a \ nowomral,.inom. 4N, BY GAUGE recess in dry sand. READING. Clay and sand are used to form a dam and the molten babbittispoured into the hole. On RUBBER FRONT BRAKE WASHERS TURN OUT PACKING cooling, the metal is hammered. ROD HANGER. NUT IF NECESSARY _ / TO FIT GAUGE. Clean Way to Fill Grease Gun POSITION AFTER CORRECTING BY GREASE BENDING. GAUGE /G INTERFERENCE DRAG LINK OF AT THIS POINT. STEERING GEAR. "SECTION THROUGH SHELL OF COMPRESSION SECTIONAL How, front brake rod hanger was bent to SPARK PLUG TESTER. VIEW. clear brake action. .1boiy is sectional views of cylinder, shuw- ing spark plug replaced by tire gauge. MHE owner of a light, popular type I IF, car owner findsitdifficult to METAL DISC OR ' 1 of four-wheel brake car noted when determine if cylinder leakage exists CUP SHAPED LID making a sharp right turn that the left WITH HOLE front Nvheel would lock and cause the by turning the motor over by hand. A PUNCHED TO FIT simple and yet effective means of de- NOZZLE OF GUN. car to come to a stop.It was found. termining this leakage is %yid) a tester, after many trips to the service station made from a tire gauge and a spark and numerous brake adjustments. that plug shell, as illustrated.In fitting the the steering drag link was located close tire gauge, it may be found necessary to to the brake rod of the left front wheel. turn some metal out of the packing nut Illustration shows way tofill greatitipor. The hanger was positioned. so that the of the plug.Fit rubber washers around drag link caught into the hanger and the flange of the gauge to make it a THE fillingof the grease gunis applied the brake. The owner found that tightfit in the shell.The compression usually a messy procedure. The idea the trouble was easily corrected by bend- may be found easily by this means. of one car owner, to avoid this slow and ing the hanger away from the drag link. January, 1930 Science and Invention SO3 You Can Make These Illuminated Table Decorations By Josef W. Von Stein Lighted balloons, espe- ciallyifofauniyue animaltype,willde- J light the youngsters or Details of 4. 4; serve asbasic decora- wiring tw tions for an indoor gar- onetype den party. of place cards.

The snowball and poinsettia platy cards grace this Christmas table with a touch of cheerful holiday color.

Illustrations by coulic.y ut Edison Lamp Works of General Electric CO.

l'aricoloredelectriccandles go.le the table charm and dignity. The lower diagram shows clearly how to,,rake theelectri- callylighted paper candles.

ASURPRISINGLY dinner, wedding and the banquet. large variety of deco- Roughly speaking, the materials used fall rative lighting effects into two classes-the lighting equipment in- IAINIATURE cluding lamps, reflectors and wiring and the can be easily obtained, with a SOCKET littleingenuity, from mate- decorative paper accessories. rials usually already in the home.Lighted The larger lamps -25 to 100 -watt sizes crepe paper flowers, lighted character dolls, ORk -are used only to a limited extent, such as producing of miniature flood -lighting place cards of individual creation, favors and NAIL effects on the table or in the room.Both novelties of all kinds can be made by placing SASE lamps in already familiar paper forms.Their white and colored lamps are used.In in- use is not limited to seasonal and holiday par- -tances where the decoration is elaborate, ties, because general functions such as lunch- metal reflectors, (Continued on page 830)

eons, formal dinners, bridges, receptions and the like can be Large !ighted figures, which add a cheer- made much more colorful and interesting with them in ser- no.etothe party, are readily con - vice.This festive lighting ihould not be limited to spelling :fruited.Drawing totheright shows the Yuletide greeting, but can be extended much further and interiorconstruction of smaller figures. made the keynote or central feature of the party, dance, Method of making lighted paper flowers: A, paper flower petals; B, supporting wire for stem; C, paper binding together electric wires and supporting wire; D, short lengths of spool wire.

A Science andInvention January, 1930

DIM DIM WHITE RED LIGHT RED LIGHT LIGHT

SQUARE SQUARE PULL ROUND PULL PULL, MESSAGES BLANK APPEAR CARDS UPON BLANK CARDS IN RED INK MAGIC

,1 number of rards are examined under a instant and then the 4e'/rife light is turned dim red light and are found to be quite on,revealinglengthymessagesonthe unprepared.The room is darkened for an cards..

The Change -Maker No. 77 of a Series Conjuring With Sweetness 'THISisan absolutely new effectin I conjuring which produces the appear- is an after -dinner trick whichre- ance of being a difficult sleight-of-hand HEREquires no preparation.At the end of trick.The hands are exhibited empty, Spirit Messages De Luxe a hearty meal the wizard sips a little of both back and front.The magician re- his black coffee, containing neither sugar THIS is a new and novel method for nor milk. Reaching into the sugar bowl, he quests the loan of a dollar bill, which he uncanny rolls up into a small tube -like form.Ile I presenting a striking and removes a cube of sugar, carefully places then pushes this into the palm of his hand spirit seance. A group of spectators are it upon the surface of the coffee in his seated around the magician's table, who in cup and causes itto mysteriously remain and on opening the palm we find the bill aspirit thiscase assumes therole of afloat. At theword of command the hasbeentransformedintothecorrect The room is dimly lighted by . change of adollar. medium. sugar disappears.The magician adds milk a red light.The magician presents a great The secret: A small tubular tin feke is ordi- and cream, stirs the coffee and drinks it, many blank cards about the size of proving unpreparedness. provided with a spring clip to hold the nary visiting cards. The spectators arc Loins.This is attached to the sleeve with requested to take one or more and place The secret :The magician actually takes an elastic band, as the diagram indicates. them down upon the table and cover them two lumps of sugar, but inserts oneui The opposite end of the tin feke is pro- with the palms of their hands.The me- diem in an upright position as the dia- vided with a hair which loops around the gram shows.To all appearances one cube The hair helps the magician dium states that he has an instantaneously index finger. writingspiritthatwillproduce lengthy remains afloat, but disappears as the one pullthetinfeke into the palm of his beneath it melts. hand, whereupon he inserts the dollar bill, messages upon each one of the cards and removes the coins and lets the feke go. on both sides thereof in only a fraction of a second.For this purpose the spirit requires total darkness.Having thus ex- CUBE OF SUGAR plained the situation, the magician turns FLOATS !!' out the light and a second later pulls the chain of the socket, turning the full glare of the white lightinto the room. The cards. when examined, contain mysterous messages, boldly written in red color. The secret:The cards have all been previously prepared by writing messages upon them, using a thin camels hair brush and a red water color paint.The paint must be carefully mixed and this should preferably be done under the same red light which isto he used in the seance. Itwill he found that a red ink can be prepared which will he absolutely invisible when illuminated by a red light. The white cards also appear red when so illuminated and hence the writing cannot he seen. Evenifthe cards are carefully examined thespectatorswillnot know that the messages have already been writ- CONCEALED CUBE ten upon them.Itis only when a white light or some other colored light is turned on that the writing appears visible. (Many other variations of this trick will readily suggest themselves to the amateur magic worker.If you have not mastered a few of the pocket tricks described here each ntonth, you don't know what fun you are missing.-EDITOR.) January, 1930 Science and Invention 803 Ultra Coin Box TRICKS wherein coinsarcemployed are HALF DOLLAR ever popular with the modern magician. SILVER PIECE Many times an occasion presents itself wherein the wizard requires some novel way for se- DUPLICATE cretly substituting a bigrrowed coinfor one HALF of his own.This novel piece of apparatus will he found quite useful on such occasions. Half -dollar sized coins are most commonly used by sleight-of-hand experts. They are sufficientlylargeto beconvenientlyseen, COIN and likeeise prove a suitable sizefor han- BOX dling. A half -dollar, after being borrowed from some spectator, is marked for identification.The magician illustrates that the coin w illfitconvenientlyinto a circularrecess prepaged forit,in a small square box. designed as illustrated.The coinisthen re- COIN BOX moved, and the lid of the box pushed into CLOSED position.The box is placed in full view upon a table.The pocket piece is now vanished COIN be any method the performer may desire, VANISHES and upon opening the hi ixitis discovered to FROM have mysteriously found its way back again HAND and is identified by its mark. AND The secret: The box really has two cavi- APPEARS IN tieslarge enough to hold a coin.One is in the lower section. the other in the upper. COIN BOX The two suctions are held together by a single screw acting as thumb. The marked coin a pivot.No matter which way the box is turned, either ofthe is exchanged for this duplicate by partswillserve. secretly turning the box over whenillustrating it. A duplicate half -dollarpieceisfirstcon- conceive that one coin Readers will cealed inthe cover of the box, and isheld in place by the is always in the box, in spite ofthe fact that it seems empty.The box may be made of cardboard. Trophy Cups forModels Magnificent Cup Given forApproved Models

THE readers ofthispublication have been clamoring for a return of the Model Department. which has been made famous throughout the country and which has been an incentive to the students of model engineering in all its forms and phases. The Model Departmentvas started several years ago.At that time the hest model submitted during a month was awarded a magnificent cup, hand- somely engraved with the words, -Sci- ence andInventionModel Trophy." Maury contestants founditdifficultto get the trophy because of the really excellent mogleis against which they had to compete. The1)1:tit entered upon which will give the makers of good models a better opportunity of winning one of thecov- eted prizes has been somewhat changed. Now any model accepted by the editors Mr. Brog;:n holding one of the be working models or pot. accordingto and published in sa AND I NVEN- Model Trophy Cups, and some the subject handled.'I he models may excellent models similar to those Aux Magazine willbe awarded this be made of any available material. beautiful prize. In soon to be available tomodel The cup itself which is given all cases the models must be sent to the enthusiasts. as an editorsby parcelpost,expressor award measures 17V,inches overall freight. prepaid. is looked upon favorably and it is pub- and weighs nearly five pounds.Like It is suggested that models made from lished. the handsome engraved cup will allotherfine cups. this oneis gold - parts of a construction outfit should not he your reward for permitting others to lined. The cupisfurther engraved beforwarded. While such a model duplicate your original design. with the model maker's name. would not be barred, it must be obvious The editors prefer in all cases to have Certain requirements are necessary in that many other readers of this publica- the model its3r forwarded for inspec- order to obtain such a cup.A decision tionwill also submit a similar article tion,photographing. and checking of is always based upon. A. the novelty of and the editors might frownupon pub- dimensions for preparation of drawings, construction: B. workmanship: C. the lication.They can get the same mate- etc.: but where itis impracticable. for operating efficiency of the model asre- rial directly from the manufacturers. one reason or another, to forward the latedtotheefficiencyofthe device So. come on. you fellows who have modelitself,the builder may submit which the model simulates, and D. the made models of ships, airplanes,guns, good photos of the model, together with care exercised in design and submitting railroadtrains,dirigibles, sketches or drawings, and a photo of to us sketches and other details covering steam engines. submarines and the like. Send the builder himself. the model.All kinds of models may beyour drawings and models to the Editor submitted for examination. .ILL REIDY, MODEL BUILD- They may of the Model Department.I f the model ERS. LET'S GO! 806 Science and Invention January, 1930

It does not require any keen sense of observation to readily classify the above scene as a happy family assembled in a cozy corner of their living -room, which, as may be seen, is evenly lighted, with soft shadow effects obtained by the overhead lighting..1 glance at Fig. 2, at the left, however, will show that this scene is actually a part of the exterior of a house; Fig. 1.

the dark interior gives a perfect night-time effect.You will notice that the room is suggested by a few carefully placed pieces of furniture and wall decorations.Nothing excessive. nothing to give away the trick except the roughness of the carpet and the reflections in the windows and careful direction and camera angle will keep those from being noticeable in the picture. In your neighborhood there must be a building so fashioned that you can make a similar setting.Do not overdo it, just suggest the interior setting and have your action carry the rest ofit.Remember. motion pictures require Inexpensive motion. In Figure 3 is a simple set that can he built for a few Home -Movie Sets dollars with volunteer labor for the club production. A half dozen pieces of wall board\viala door and a window, a few pieces of furniture and some decorations dress theset. By Don Bennett Figure 4 shows the view as seen by the camera. The background through the door is perfectly "natural," on a windy SEVERAL months ago an article was published in the (lay the grasses will ripple in the breeze and the curtains will Home Movies section describing the building of sets blow gently (but be sure the window is open so that a breeze and "flats" for the making of interior scenes outdoors. from the camera side will not look suspicious). There are some amateurs, however, who are not me- There are a few things to remember when shooting in- chanically inclined or whose economic strength precludes the teriors on exterior sets and probably the most important one investment in materials required for the setting of a fair is to choose a day when little or no wind is blowing.The sized room.To these amateurs, this article is addressed. next one in importance is to select a day when the light Do you have a home or a garage whose exterior is justis not too harsh.Hard light will throw hard and deep shadows and thus expose your trickery. A sky slightly over- cast will give the soft effect of interior illumination achieved in Fig. 1.Notice the hard shadows in Fig. 4.This picture was made on a bright sunshiny day and the shadows and lighting are hard. Possibly the easiest and most thrilling picture to make is a "Western."For years they have paid the producers the losses incurred in making the(Continued on page857)

Fig. 4..This attractive "sun -parlor" interior can be readily filmed outdoors, as may be seen in the illustration to the right.

like an interior?Then use it as a setting for your exterior interiors.Figure 1 on this page shows you a happy family group assembled in their living room, Mothersewing while Daddy explains the wonders of an animal book.Notice the nice even lighting, the soft shadows cast by the overhead lighting, the full tones of the faces.Isn't it a homey atmosphere, the cretonne drapes at the windows, the soft picture on the wall, the comfortable chairs and cosylamp? Now look at Figure 2.See the much trampled turf in the .1airam .girodire..,44-,- foreground, the roof of the garage, the open doors at the Photo, Courtesy Eastman Ti.luk01. right.The curtains are on theoutsideof the window and Fig. 3.A "sun -parlor" set i.lbe cheaply constructed. January, 1930 Science and Invention 807 Making SILHOUETTES Without SCISSORS By Utilizinga New Simplified Method of

1 Photography, Anyone CanProduce Beautiful Relief Images r'I By H. H. Dunn

The pleasing"silhouette,"reproduced at the left, was made 7lb. with the camera and sub- 1 kb ject shown below. The subjectis placedin 11Y front of an illuminated screen, with the camera in the position shown. N interesting new kind of photography-done as easily with the Ntwo -dollar camera in your own home as with the two -hundred -dollar instrumentsinthe studio-has been devised by Otto Dyar. cleveryoung photographer of Hollywood.Most amateurs have been accustomed, in making their pictures, to seek a spot where the sun's light fell from them toward their subjects.I3y the new method the light must be from behind the person or object to be photographed. The results are as beautiful as etch- ings. done in pure black and white, xvith a wide range of possibilitiesin half- tones through the placing of reflected light from a mirror on any part of the subject. Silhouettes more perfect than any ever cut from black paper xvith sharp scissors may be made andpre- served forever in the negative; portraits as desirable as pen -and -ink drawings t my be produced by the careful amateur. and the discovery holds endless possi- Christmas and other seasonal cards of pleasing appearance frequently have sill/on- rite figures on them. (sr) hereis WALL e&%>, - a way to t gzr, V make true silhouettes of your friends < !iilities for caricature, with the amiable and relatives for use on such greeting assistance, of course. of the subject. cards. Owners of home motion -picturecam- SCREEN eras and projectors may make and enjoy PERSON--""#. whole reels of these silhouettes, for the LPLATFORM idea is as applicable to action pictures as to "stills."One of the large motion- picture corporations is preparing script, costumes and a special company for the production offolk -lore and fairy-tale playlets.insilhouettes,forchildren. This will be the first work of the kind ever done, and the activities of children in and around the home should beas easy to film in this black -and -white as are those of the stage characters. Proper positionof screen, subject and Elaborate equipment, with controlled camera in the making of silhouette photo- lighting. will be used in making these graphs by sunlight in the home. IContinned onmy,'83(o) January, 1930 808 Science and Invention How to Build a Record -Winning Plane Model Novel Plane Model Which IsMade of Balsa Wood and Is Extremely Popular With Tyro and Ex- pert Model Builders By Hi Sibley

CecilSchwartz andhisprize-winner (similar to that described below), which flew for8minutes and 44 seconds.

.? 2 STRANDS WHITTLE V RUBBER BAND GENTLY RIB REAR' HOOK

NOTE THAT THE WING SETS LEVEL WITH MOTOR STICK. IT IS NOT NECESSARY TO TILT UP LEADING EDGE WHEN, IPS ARE CURVED' PROPELLER ROUGHED OUT 3/,5 FRONT THICK

"S" HOOK TO DETACH 3/.8. RUBBERS FOR MECH- THICK ANICAL WINDING y13",

ji1141PROP BEARING FIN AND STABILIZER FINISH CONCAVE SIDE OF LIGHT BRASS OF BLADE WITH SAND- GALV SHEET OR MOTOR STICK IS SANDED TO IAC THICK PLACE BLADE FLAT ON PAPER OVER A ROUNDED N°13 MUSIC WIRE lc HEAVY TIN. Ms BALSA TABLE AND MAKE LIGHT CUTS AND TAPERED BLOCK. PROP SHAFT WITH A RAZOR SHARP 3/e GOUGE END VIEW ( THIN BRASS CUT DIAGONALLY DIRECTION WITH FINE TOOTH OF PROP WASHER --,1 ll OF FLIGHT ." ."-11ARri HACKSAW FOR FIN FINISH BLADES TO Sic; OR LESS AMBROIDED AND) WING CRADLE BOUND WITH THREAD FOR MOTOR STICK METHOD OF CURVING WINGTIP SECTION !TIP OVER RIB UNTIL AMBRO!D DRIES X Vis- ENDS RAISED 1/4 ABOVE \lb ye" CENTER - V2 -

I BLOCK . 11/4 r BLOCK RIB FOR 'WINGTIP SCORE WING ON CENTER LINE AND BEND TO DIHEDRAL ANGLE DEFORk CURVING WING- TIPS.-AMBROID CRADLE AND HOLD IN PLACE WITH PIN TILL DRY This model plane weighs less than one -quarter of an ounce and will stay in the etir until the rubber driving the propeller hasentirely spent its force.Thr sizes of all parts and complete directions for building this balsa tractor plane are given. F you are good at working with balsa fair mark for a small plane of this type. wood. you can make alivelylittle There is considerable variation in balsa tractor plane model from these plans. wood, and if you have any choice select a Itis constructed entirely of this unusual clear, straight -grained piece ;14in. by!.'t V0O(l and weighs less than one-fourth of in. by 11in. of so-called "hard" balsa for an ounce. and is so light, in fact, that it the motor stick.Soft balsa will do for will stay above ground until the very last ordinary flights, but the rubbers cannot be turn of the rubber.Its distance depends wound as tightly. entirely upon the care with AN'hiChitis First make the slots for stabilizer and made and yourskillin launching.Of fin. A piece of hacksaw blade with fine course.the adjustment of the wingis teeth is ideal for this purpose.Cut slowly everything in even flight, and experiment so the slots will be accurately in themiddle willdetermine the best location on theof thestick. Thisisimportantinthe motor stick.Although it shows best per- stabilizer slot,forifitis not perfectly Photograph of theall -balsa formance in indoor work, on still days out- level the wing will have to be adjusted to plane, capable of 200 -foot flight. sideittillfly from 100 to 200 feet, a counteractit. (Continued on page$51) 11 .1.Inuary, 1930 Science and Invention 809 Mirth -Provoking Stunts for Home Entertainment Tricks withaPhonograph By Esten Moen Unusual Experiments for Talking Machine Owners Are Easily Performed GOOD Citizens Call You ..."Oh. all,gathere heck,howdoesa ye,unto here, phonograph turn formutuelleenter- backwards,ordina- tainment"M u s i c rily-it don't? When hath charmsto the spring of the soothe a naked machine is RUN breast"-no, a naked DOWN, spin the savage, - oh, dear record backwards NO, I mean a sav- with theforefinger age b r e a s t. But, (See Fig. 1). why is music? Why I'vegot an old- should lonely monks time phonograph- \1) and bishops on the , one ofthosehorn oldcontinenthave 1/ affairs.One day 1 shut themselves up held the horn on a withindankdun- record being played geonsforthesole 111111111111111111 on another machine. and express purpose Fig. 1-The above thawing shows how Fig. 2-T1 e system of double repro- so two horns were of doing research a record is turned backwards. duction isillustrated above. reproducing a in- main music ?What- stall/a-andwhat an ever answers there be, must needs com- interference-WOW !A colored gen- portwiththatfundamentaldoctrine: tleman was singing "All In Down and MUSIC ATTRACTS PEOPLE. Out"t it was Bert Williams) from one There's a fortune in gold in good music horn, and the other horn caught him re- -for the good composer.A composer peating the whole thing one step behind- will rush around fiercely seeking inspira- somehow, the suggestion was conveyed tion-beat his brains, and drink black thathere was indeed a TIME MA- coffee-but a composer, y'unnerstan', he CHINE. even more so than a clock. I dunno why is music.How can a com- suppose old man Einstein could imagine poser get mood into music-his music be- funnier things belonging to the time di- ing butasuper-complificated matrix of mension.... vibrations within vibrations?But you A portable phonograph with a busted just play a phonograph backwards, and spring is temporarily dead-but it can be you'll get the integrated ballistics of in- spun around with the forefinger to con- vertedsyncopation-funnything,but tinueitsformer capacity as an enter- some of these modern English "songs" tainer.The chap illustrated in Fig. 3 is i really,they'remostsillydoggerel doing just that-but he is furthermore rhymes) when spoken "backwards" sound investigating into a peculiar "nerve re- like Greek, Hebrew or Polak.Listen to flex"inhis body.With one hand he this one: turns the record-a car/w/o-and he is "Hooey vin vawr lamia" turning his right foot (shoe) in the same -isn't that just swell Greek?It means, Fig. 4-.1bove we see how the "diabolic direction of rotation.That is compara- "I'm in love with you." from that Freed- sound ray" is produced by using a re- tively an easy task-but, if he wills to man -Whitson dance hall classic, "Let Me flector for directing the Can'el. (Continued on page856)

Fun With Music

ANYONE possessing .1 phonograph has the raw material for executing a number of risible stunts. Even a broken machine can be employed in performing some ofthetricksde- scribed.Littleadditional Fig. 5-Sound waves pass through the Fig. 3-.1 nerve reflex can be demon- apparatus is necessary. body of the man standing in front of the strated vith the right hand and foot as phonograph. They strike the smoke ring shovmsgbove. and turnit around 90 degrees. Science and Invention HowtoPrepare Dyes and Pigments

Chemical and electrical means of making dyes, which the student chemist will find useful and instructive.

By Eugene W. Blank Mix pinball(' anhydride and resorcinol intimately in a mortar, place in a deep crucible and heat on a sand bath, the bulb of a thermome- Remove the melt front the crucible with a small knife and ter being embedded inthe finely powder it with mortar and pestle.Place the powder in sand, and add zinc chloride. a beaker with 250 cc. water and 10 cc. concentrated hydro- chloric acid.This dissolves all the substances except fluores- Place the a b o a, eproduct, cein. The fluoresceinisfiltered from the solution and powdered, in a beaker with washed with water.It is then transferred to a watch crystal 250 cc. '11 of water and 10 cc. of and dried on the water bath. By closely following directions 1,,todio.i 1 hydrochlor;c acid andstir. a large quantity will have been secured. Fluorescein dyes silk and wool yellow, but it is not much THE art of dyeing is used as a dye.Its halogen compound is the magnificent dye one of the most an- eosin. cientof subjects. To prepare eosin, place about 10 grams of the fluorescein Since the very earliest of in a flask and add 65 cc. of alcohol.Place 10 cc. of bromine times man has known how in a small separatory funnel or burette and allow it to slowly to color and adorn his per- drop upon the fluorescein.As the bromine is added, the sonal belongings. Old fluorescein starts to dissolve and finally a clear, reddish works of art are noted for brown solution is obtained. As more of the bromine is added. their resistance to the rav- the tetra -bromide forms and separates out in the form of age of air and light.The dark leaflets. earliestdyes were those When all the bromine has been added, the reaction mixture extracted from the roots is allowed to stand for two hours, and then the precipitate is and berries of various filtered.Wash several times with alcohol and finally dryon plants such as indigo and the water bath.During the heating the color of the dye alizarin.But since the becomes brighter. As eosin is insoluble in water, the sodium latterpart of the eight- salt or ammonium salt is largely used for dyeing. eenth century, when ani- To prepare sodium eosin, mix six grams of eosin line dyes were first discovered, there with one gram of dry sodium carbonate.Place the has been a tremendous increase in mixture in a small the number of dyes being produced. flask a n d moisten Whereas the early dyes were all ob- with water and tained from natural sources, many then add six cubic thousands are now preparedarti- centimeters ofal- ficially front coal tar and its deriva- cohol. Heat until tives.A few natural dyes are used no more carbon di- at present, but the greater number oxide is given off. used are manufactured front coal tar Add thirty cubic and in many cases severe competition centimeters ofal- has arisen between the two classes of cohol to the mix- compounds. ture and heat.Fil- Dyes ter the solution while hot and on FLUORESCEIN isone of the (Continued on most important of artificial dyes, Milt' 856) and it is technically prepared by the reaction between phthalic anhydride Kanari.e, a yellow It forms a dark red dye, is prepared by and resorcinol. decomposing 'a solu- crystalline powder and when dis- tionof potassium solved in alkalies it has a red color sulphocyanide in and a magnificent green fluorescence. water by electrolysis. To prepare it mix intimately in a mortar 15 grams of phthalic anhydride and 22 grams of resorcinol and Natural Organic To prepare eosin, ColoringMatter,by place 10gramsof put the mixture into a deep crucible. Perkin and Everest. fluorescein in a flask Place the crucible in a sand bath and Synthetic Coloring and add65cc. of al- have the sand well packed around it. Matters, by Hewitt. Synthetic Coloring cohol.Place 10cc. Heat to 180° C. (356° F.) (the tem- Matters, by Thorpe bromine in a drop- perature can be ascertained by plac- and Ingold. DyesClassifiedby ping funnel and al- ing a thermometer in the sand). To Intermediates, by low itto drop into the fused mass add 8 grams of zinc Shreve. the flask. TheFactoryPrac- chloride, then increase the tempera- ticein Manufacture of ture to 210° C. (410° F.) and keep Azo Dyes, by O'Brien. To prepare sodium Coal Tar Dyes, by eosin, mix 6 grams heating the mass until it is quite dry. Fay. of eosin and 1 gram Before adding the zinc chloride,it Names of publishers gladly furnished on of sodium carbonate, should be well dried by placing in a request. add 6 cc. of alcoho.! small dish and heating. and heat slowly. January, 1930 Science and Invention Sll FirstofNew SeriesofBrain

Teasers B,

Twenty-five Dollars in Prizes WE have in this issue the first two specimens of a series of the puzzle man's best brain -teasers; one being of the popular word - puzzle variety and the other with a mathematical flavor. A FIRST PRIZE of $10 will be awarded to the person sending correct answers to the two puzzles accompanied by the best expressed analysis of the "1930" puzzle.While this problem may yield to experimental methods, actuallyitssolution involves aprinciple in fundamental mathematics well worth learning. A SECOND PRIZE of $5 will be awarded for the next best analysis and correct answers to the two puzzles. TEN PRIZES of $1 each will he awarded to the ten persons who send the next best analyses of the "1930" puzzle, together with correct answers to the two puzzles. Answers mustbereceivednotlaterthannoon January15th, addressedto "Puzzle Editor,"SCIENCE. AND INVENTION, 381Fourth Avenue, New York City. All contestants must abide by the decisionsof Sam Loyd, who will examine all papers and award the prizes. Papers of identical merit, tying for any one of the prizes, will each receive the full amount of the prize tied for. Answers and prize awards will appear in the April issue of SCIENCE AND INVENTION.

The Canny Scot and the193o Puule HOOTmon."Ishouted to Sandy MacNab as wepriately uttered by Napoleon: "Able was I ere I saw Elba.' passed on the street, and my greeting brought forthYou see, it reads backward as well as forward. a reply front the canny Scot that was both witty and puzzling. The 1930 Puzzle The skeleton of Sandy's retort is set forth in the strip of type in his right hand. Just sprinkle one certain letter among In Sandy's left hand are displayed the ten digits with those O's and H's to make Sandy's remark complete.It will which we perform ail arithmetical calculations.They are be in the form of a palindrome, that is, it will read the same called digits because man first learned to count upon his ten from top to bottom as from bottom to top. fingers or digits. The palindrome is probably the earliest form of word- Let us see who can arrange the ten figures in a sum which puzzle, especially if itis true that Adam introduced himselfwill add up 1930.All ten figures must be used and none to Eve in the words:"Madam. I'm Adam."The mostmore than once.Itis permissible to employ proper frac- famous of palindromes is that tt hich might have been appro-tions, but the top-heavy sort is barred. Sam Loyd the Puzzle King ATHOUGH "a prophet is without honor in claimany responsibility to any reader willing his own land," surely a king needs no in- to risk insanity or tvorse.There is no telling troduction to his ardent disciples.A conserva- but that Mr. Loyd may create another furore. tive, statistical friend of Sam Loyd came to the with even more disastrous results than his famous conclusion a number of years ago that the puz- d4-15 puzzle 'way back in the '80's.This puzzles invented atthat time by Mr. Loyd had zle,we are informed from an authoritative reachedatleast300.000.000people. These source-Mr. Sam Loyd. himself, to be precise- figures. says Sam Loyd. cannot look him in the "burst upon our unsuspecting planet like a me- eye. However, the fact remains that he is the teor out of the sky.The shattering reverbera- worshipped idol of all puzzle fans-and where tions of its arrival spread tvith almost the speed is the person xvho can resist the urge to get on of light to the furthermost corners of the globe. the mat for a tussle with a puzzle that impishly It leveled caste and melted hard human hearts. challenges-"Let's see you guess me." Like a medieval plague.it played no favorites The editors must therefore be forgiven for among its victims, and old and young, rich and their justifiable pride to be able to offer their poor. wise and otherwise succumbed to itsir- readers the latest of the Puzzle King's interest- resistible onslaught." Although the editors of ing and baffling-we hope-efforts.Itis, however. with SCIENCE AND INVENTIONare generally meek and genial souls, sometrepidation also that tve send into the world thesethey are looking forward with keen anticipation to the brain -children of Sam Loyd's.Right here and now we dis- results of this newest puzzle creation of Mr. Loyd's. 812 Science and Invention January, 1930 HINTS

STRIPS forMC' HOME

LAYING STRIPS ON WITH SQUARE WORKSHOP PHOSPHOR BRONZE CLIP

Cleaning aFlat File 4 First Prize$10.00 6' Temporary Mitre Box CLIP SOLDERED ON UNDER SIDE M 0 overcomethehandicapofa LOWER CORNER SILVER SOLDER RIBBON 1 brokenmitrebox,thefollowing PRESSED INTO (USUALLY 314 -WIDE 003 THICK Two strips FILE ONLY T procedure was employed. - -"*-Y were nailed lightly with brads on either BLOCK side of the line on which I was to saw OF Solder Dispenser and on both sides of the chord. A SOFT WOOD a strip of brass or other suit- DIRECTION OF MAKE square was used to place the strips on STROKES able material. 8" long. wideand the wood.-1"ernan I'. Johnson. 1/16" thick.Curl one end into a MAKE a small block of soft wood.loop, leaving an opening as shown in Soldering Hints I Hold file firmly on flat surface with sketch. Fastenclipto undersideof the hand.Using the front bottom edge holder,thenslipsolderinto curlof ofthe corner of the block of wood.holder.-//. K. which will take the form of the teeth and grooves, slide the block along the tile.- A Hack -Saw Vise grooves or directly across the HACK SAW Frank Placerian. FRAME ADJUSTMENTS ti WIRE TO HOLD 4 (FRAME FROM Holding Screws in Line SEPARATING is necessary to put a WHENit FRAME PIN screw in a close place. a screw - I REVERSED holding device is not always at hand. WING NUT I I the slot in the screw head is rubbed AND over a piece of beeswax, soap or par- SCREW affin, so as to fill the slot, the screw will stick firmly to the screw driver.-Darid Jcnkins. Q MALL solderingironswillretain L., heatifplenty of copper wireis Below is shown a means wrapped around them. leaving only the of holding a screw to the ORIGINAL POSITION screw driver. OF WING NUT HANDLE :ip free. --Dr. Ernest Bade. AND SCREW REMOVED Handy Drill Sight R..\IOVEthe handle, wing nut. and 71 \\'O cotter pins, one1 inch long and -crew that tighten the blade. and .1 another 3 inches are linked together insert them in the frame again so that intheend where theyopen. The they are reversed.A piece of wire is smaller oneisfastened to the upper wound around the center to keep the blockina hole drilledinthe center framefromspringingapart. -Frank oithe block; the other cotter hangs Placerian. loosely.-Martin G. Irinterton. FILL WITH SOAP "II\p_11 PA RAF FINE Novel Polishing Wheel MAKE a head or chuck about 4" to ;i" deep and lay in broken carbo- rundum or small broken emery wheels. Melt sulphur and pour in around pieces Y4* $10.00 MONTHLY FOR while hot.-H. Pf (VT-. BEST HINT SEND us a photograph or

sketch of your own hint 1L-321 forthe home workshop. CHUCK BROKEN EMERY WHEELS ti0.00 is paid monthly for the MOLTEN SULPHUR hesthint accepted and pub- i ished.Others that we publish are paid for at regular rates. I iere is a chance for you to win

1 prize for a useful workshop Flow to make a simple sight for hand -drill from two cotter hint. c.:=1 01. pins. Makiny large grinding q....neel from January, 1930 Science and Invention S13

WINTER Winter Funon a Toboggan -Ski has comeLearn Fancy and the snow-Skating with covered hills beckon withthe this Device white hand Jack Frost.But many dangersare the attendant of wintersports, skiis that trip their ungraceful owner, sleds that refuse to stop and toboggans that like to leave the slides.Pictured hereisa device which combines the speed of the skiis andtobog- gans with the safety of a good old bob -sled.A wing -likeprojec- tion isattached YOU canconstruct,very easily, this tothe prow of device for learning fancy skating the toboggan. as with a long pole, a cross -arm of 10 or shown in theil- 12 feet long, a rope. several pieces of lustration. and wood 1 inch thick and a strip of leather projectsabout or canvas.\\little down the top of the three feet on each pole untilitispointed, then bore a side. No longer 14 -inch hole in the top 6 inches deep. needthewinter Drive a 4 -inch rod 12 inches long into sportsmanfear this and fasten one end of a rope around Above is shown the forthesharp it with a non -slipping knot so it won't toboggan with the curve or the de- tighten.Set the pole through the ice to wingnz: b i e tipre- pression at the freeze.Nail the wooden blocks on the vents accidents. foot of thehill. pole five feet above the ground and tic P. l'. l'an Pettin- thecross -armtothepolewiththe gent. leather strip.-Dale l'an Horn. Rubber Checker Board Crate -BoxArmchair A Snowball Catapult ANOVEL checker board can easily THE baseboard is 48 inches long and be made from a discarded rubber CRATE BOX CUT TO FORM 6 inches wide. Two laths are used inner tube. ARMS OF CHAIR First clean with asteel to guide the snowball.The cross -piece brush. mark into squares (64) and color is 18 inches wide. 2 inches in thickness them with India ink.Paint with elastic BOXES NAILED TOGETHER varnish FOR A SEAT and 4 inches in height.A hole is cut to make board smooth. Cut in the cross -piece to allow the ball to go checkers to size from tube and coat with out. The inner tube is 3 inches wide elastic varnish.-Etheard A. Kallal. and about 50 inches long.-E. Ozag. CROSSPIECE OPENING CUT FOR TUCK -AWAY CASE

UPHOLSTERED BOX CHAIR CUT SQUARE PIECE COLOR SQUARES WITH FROM OLD BALLOON WATERPROOF INK INNER TUBE v ERV usefulandeasilycon- 4 4 structedarmchair may he made COLOR AND CEMENT from two grocery boxes. Remove the TWO TOGETHER cover and one side of a box.Cut each end down to a height of 5% or 6 inches from the top.This will form the body of the chair. comprising the seat. back. BOARD MAY BE and arms.For upholstering use an old ROkLEDsSLIPPE blanket or quilt for the inside padding. CUT OUT CHECKERS IN POCKET -Manki Field. MOUNTED 814 Science and Invention January, 1930 TOY 1UNNELS Easily Made By Dr. E Bade

The finished tunnel willlooklike the above. This particular typeof tunnel, intercon- nected with a toy construction set railway, simulates a bore through a mountainside.

The first step in the construction of toy are sprinkled over the frame.In among tunnels is the skeleton framework. Asmay these brown shades a few grains of heseen, this easily built framework is for an elevated tunnel. brighter colors are sprinkled, such as This arched bridge,whichcan be used in blue,red. yellow and green.To in- C1-111-DREN always like to have a conjunction with an elevated tunnel, is very crease the effect and to make the tunnel tunnelfor theirtrain, but the readily constructed with the aid of one ofseem as if cut from rocks, sand is sprin- larger ones are quite expensive. the 'well-known toy construction sets. kled on at the same time that the colors Strong, substantial tunnels are not at all are added. The tunnel may also be col- difficult to make and require very little covering as possible. This will heighten ored by adding small portions of glue to material.First. any kind of a board is the final effect. the ground earth colors and painting taken which must be almost twice the The tunnel is now almost finished ex- these on "any -which -way." These earth width of the train to go through thecept for stiffening and color.Stiffness colors mixed with glue dry rapidly and tunnel.The length of the tunnel is im- is provided by painting the entire cloth are just as effective as if oil paints were material and depends upon the length frame withfreerunning carpenter's used. of this board. A rough skeleton of thin glue. When dry, the process is repeated. \lien making- an elevated railroad, strips of wood is nailed to the sides of After the third coat has been applied the tunnel must naturally be placed on this board and these give the outline ofand has dried. the old bags will be quite some support.Under these contlitions the finished tunnel.After nailing these stiff.There are two or three ways inthe tunnel. whilestillinitsskeleton strips together. take sonic old bags or. which the tunnel may be colored.The stage. is provided with four legs which better yet. sonic old potato sacks and simplest is to brush on another coat of are braced internally and the bags are nail these to the skeleton frame.While glue and, before the glue dries. ground made to cover the lower part as well as doing this provide as many folds in the earth colors of various shades of brown the upper part of the tunnel. NEW TOYS bow CONSTRUCTION SETS Walkingbeam engine that works. Working model of a motor -driven fret saw. the mainvertical TOYS, from which any number oftwo binding posts to two springsliding from one end of contacts to prevent oxidizingtendency frame. A short strip connects the long models may be made, have a fasci- lever with a fly -wheel, operated by a ration of their own. The walking beam of sparks.This contact is adjusted by means of an eccentric onthe fly -wheel small electricmotorwithreducing engine, illustrated, operates by means of The saw. which can be obtained shaft. gears. twosolenoidsalternatelyenergized. in any hardware store, is fastened to the One coil being energized, pulls down A useful fret saw can also be readily built. A vertical frame lies in the cen- center of the small movable frame. the the "piston" connected to a crank on the size. A lower end being inserted into a slotted fly -wheel.The piston reaching its low- ter of a horizontal one the same table to support the work is fastenedin coupler fastened to thisframe. The est point just after dead center on the tipper end contains a coupler that can crank has been reached, the second sole- the center of the vertical rectangle.The saw frame slideswithin thevertical be raised or lowered.The proper ten- noid is energized and the operation re- is obtained by a lever, eccentric The frame on two rods and operates by two sion peated with the second piston. arm and ratchet.A guard to protect current, which may be from any source long levers connected by verticalstrips. of electric energy, is distributed from The fulcrum is one -quarter thedistance fingers may be attached. Science and Invention Writingand Stationery Cabinet By J. E. Lovett

THE fitted in- APPEARANCEOF FINISHED WRITING , ENLARGED DETAIL OF ORNAMENT in. long by 16 in. terior of this CABINET I WOODEN BUT TON GLUED ON --I I-il- wide by /-in. thick writingand ( oak plywood will stationerycabinet 2i answer. if the solid provides ample ac- oakisnotavail- commodation f o r able), with its top writing material edge shaped as and a few books of 1.-4f reference, while the shown, being ao FIG.7 pinned to the sides, flap when opened top and bottom. forms a convenient END SCION SHOWING DETAILS OF SKIVES AND DRAWER The small shaped writing slope.The rail which is titted cabinet, which i F16.3 under the bottom is measures 18 inches FOliPENS. PENCILS. ETC.- shown atFig.2. by 18 inches by 10 It 6141ED BLOCKS----, is grooved into inches deep, should thesides,andis be made in oak.. fixed under the bot- The principal tom with glued parts are cut from blocks as at Fig. 3. 1/4 -in. timber. The flap is of 1/4- The ends or sides in. timber, framed are shaped as attheendsl' shown atFig.4, inches wide, as is171/4 the top shown atFig.5. inches long by 71/4 It is hinged to the inches wide. Re- CLEATS FITTED ON ENDS TO PREVENT TWISTING bottom, and should bates are cut at the befittedwitha back edges of the lock and key or ball sides for the recep- catch. tionofthe back. anddovetail The interiorfit- IT tings should be of groovesare cut to DETAIL OF 1/4 -inch material. FLAP receive the top and SHOWING CLEATS FIG. 5 DOVETAIL FIG. 6 Thesides,top bottom.as shown The appearance of the finished writing cabinet and details for its constructionare shown and bottom are at Fig. 4. above. .1mple accommodations for writing material and several booksare provided dovetailed; this The back is 171/2 as well as a flap which forms a support ,when (Cont. on page855) Reflectors for Amateur MovieMakers By Raymond B. Wailes /soar location"seemsratherprimitive;but nevertheless it produces the results-that of lighting up the shadows in the picture. for instance-reflecting the light up and under the chin of the subject, and under the hat visors. etc. A sheet of wall -board as large as can be conveniently painted with aluminum paint and fitted with screen door handles is easy to handle. A small stick set up in back of a sheet will act as a prop to reflect the skylight upon the subject.One The reflector sheet can be supported by the ENAMEL If/TCNEN tripod as illustrated above. TABLE TOP OR COMPOS/TiON BOARD Enameled kitchen table tops or composition THE cause for poor results with the board make excellent reflectors. use of home movie and still, or ordinary cameras, is the lack of light means of supporting the sheet is simply upon thesubject. Inusing amateur leaning it against the legs of the tripod, movie cameras,itis necessary to have if one is used. sufficient. but not an excess of light, on By reference to one of the sketches it the subject being photographed.Over LAMP SHADE W/TH 200-250 can be seen that the sheet of board should exposure is as bad as under exposure. WATT LAMP be placed so that the angle A is equal to Give the subject plenty of light, but con- the angle B. The full sunlight is reflected trol the light by the use of a reflector. upon the subject only when thisisso. Home -movie cameramen will find the Even with no sun in the sky, the reflect- use of a large sheet of wall -board as a A hand spot or flood lamp can be made ing board will cast light upon the subject mirror a decided asset to their equipment. easily withalamp shade and a 200 to 250 from the sky. brightening up the shadows. As the sketches show, the use of it "on watt lamb. ( Continuedim page 856) 816 Science and Invention January, 1930

WARM AIR GOES OUT

::1...-..

Making Balsa Spars for Model Cocoanut Shell Bird House I ) Boats and Airplanes ANOVEL fr WIRE, SCRFW T N forming round spars from balsa wren house BOARD EVL COLD AIR 1 and other light woods for model air- COMES IN planes and boats, a simple method is to select a nut with a hole slightly smaller Winter Use for Electric Fan in diameter than the desired size and to $5.00 FIRST PRIZE drive or draw the strips through it. YOUR electric fan may be made The reason for using a nut of smaller COCONUT to earn its keep in the winter asdiameter than the finished spar is that SHELL well as during the summerthe spar will expand slightly after being

months.Many times it is found that indrawn through.Pass the strip through L. the workshop as well as in some homesthe nut several times to insure uniform- t `v the room containing a heater or register ity.-SimonCherry. ^ f will be quite warm and the adjoining rooms cold.All that is necessary is to A Simple Rubber Stamp Rack installthe electricfan ina hole cut OFFICE workers who must use sev- above the door between the two rooms eral rubber stamps in their duties and to leave the door open.This gives and who areforevergettingtheir may be made from t a cocoanut shell.A a constant circulation of air that keeps fingers stained with stamp -pad ink inTft-inch hole is drilled in the shell for a loth rooms at the same temperature.-picking out the correct rubber stampsdoorway and the milk is drained off. Kenneth B. Murray. will find a great time saver and temper The top of the shell is next cut off with saver by investing in a few metal screwa hacksaw and the meat is scraped out. Removing Car Body Squeaks eyes.By hammering some small nailsThe shellis glued to a board about 7 on the inside of the desk drawer andinches square. which may be painted screwing the screw eyes in the ends of any desired color.Then a screw -eye is the stamps there will result an efficientput in the center of the board for a wire "stamp rack."Hang the stamps on thehanger.-Iern on I". oh ason. nails.-E.L. Dunbar. Cigarette Pin Cushion How to Render Paper Fireproof WHETHER the paper beplain, written,printed.or even mar- bled, stained or painted for paper hang- ings, dip it in a strong solution of alum THE practicalwaytoe iminate water and thoroughly dryit.In this squeaks in an auto body, due to thestate it will be fireproof.It will car- springing of joints in the wooden frame, bonize in a fire but will not blaze to any is to rein force it with a metal bracket.extent.-EugeneD. Yates. which may beattachedwithwood screws and bolts.The flanged triangu- Animated Toys ' lar section of the bracket forms a rigid FOR purposes of display or nursery braceforthe top joint and the leg1 -amusement,smallfloatingobjects, serves to support this from the pillar.-such as boats, etc..if put in a round C. T. Schaefer. bowl, will he kept moving in a circle if a piece of gum camphor is dropped into AHALF of a cigarette, any brand. thewater. This keeps pushing the will make .z.n excellent pin cushion. Sack -Pouring Device water fromitand the objects keepThe tobacco and paper will hold a great THE process of pouring sugar orgoing in a circular motion without other many pinssecurely andsafelyeven otherma- assistant.-E.L. Dunbar. after some of them have been removed. terialfrom a -Frank IV. Bentley. paper sackis ( NOTE: Smallpiecesof camphor a tedious one. about the size of peas can he tied to- Try this:Cut gether, preferably by passing the thread Improved Can Opening lathe bottom through the center of each piece. When rOR easy and clean opening of a tin and top of a this chain in dropped into the water it can,cutthe top about half way. tobacco can, will move like some strange water ani- Leave a bridge of inch and then mal.The slightest bit of grease mz the make another cut to the original start- surface of thc waterwillslop all move- ing point-Ruch fr. Maud/. ment.-Editm..) STARTING POINT BRIDGE END POINT OF OF SECOND CUT FIRST CUT DIRECTION insertitinto the Patching Sacks OF FIRST mouth of the bag OLD sacks may be patched by past- CUT

and thenput a ing a patch of the same material TARTING END OF POINT rubber handover the holes and ironing.The heat of SECOND CUT OF FIRST around itasthe iron hardens the paste and the patch CUT shown in illustra- will outwear the rest of the sack. Com- tion.-Frank mon flour pasteis used.-/-ercm Bentley. Johnson. January, 1930 Science and Invention 817

Handy Hook for Strop

Handy Kitchen Towel Rack and some fine valve -grinding compound. THIS consists of 2 pieces of ,;.4 -inch The compound with alittleoilis wood, two lengths of dowel stock tospread over the metal object while a slip into holes drilled in the end pieces,round piece of corkt wood will do, but is not as good)is placed in the drill press instead of a drill.Rotating the TOWEL RACK cork over different parts of the object IN USE will result in overlapping whirls, making the article look much better. GUIDE A hand drill can he used if a second°THE tourist frequently finds it diffi- DOWELS person holds the cork in one spot.For cult to locate a convenient hook for this purpose use a board that has a holehis razor strop.Here's a novel one. initthesizeofthe cork.-A. 0.Take a small brass safety chain.. - Put the first link on the eye of the strop. as shown.Insert a match, nail or other bar -like object between the two.This will hold the strop very well.-Frank $5.00 II'. Bentley. FRONT VIEW will be paid each month for Adhesive Paper Moistener GUIDE GUIDE the best wrinkle or recipe sub- ANold film spool can be used very mittedtotheeditorsand handily for this purpose.Bend the 0 which they accept and publish em:s of two nails at right angles, after in these columns.All other removing the heads, and place in end of ideas accepted and published and 2 strips of 3/8 -inch wood, forming inthisdepartment will be slides which are fastened with screws. paid for at regular rates. Ad- A knob in front serves for pulling rack dress your ideasto-Editor out.-Vcrnon V. Johnson. Wrinkles and Recipes. Sharpen Razor on Paper ON a motor tour I forgot my razor strop.I got a newspaper, foldedHow to Make a Reducing Glass it and tied both ends.The paper fold'TAKE an ordinary wafer razor blade was of six thicknesses, the length that 1 and fill one of the holes with water. The drop will remain suspended.Any picturecanbeviewedthroughit, film spool. Wrap several turns of cloth greatly reduced in size.Hold the bladeabout spool and then submergeitin about one inch above the picture.The wateruntilthoroughlysaturated.- picture should be upside down, since the -Frank W. Bentley. image is inverted.It is often desirable to know how a drawing will look when A Trick Cigarette reduced for printing.This method isPr HIS simple trick consists of insert- especially suitedfor viewing illustra- ing a toothpickinto an ordinary tions which are to be greatly reduced in cigarette. When it is smoked in a holder size.-Frank Schmulowitc. the ashes will have a tendency to ad- here an unusually long time, occasion- (It would always be a good plan to ally until the cigarette has been smoked cover the illustration with a piece ofway down to the holder.-Lcslic F. Car- glass, to prevent the water from acci-penter. BEFORE SMOKING dentallydroppingonapen -and -ink drawing,-Editor.)

Brown Stain for Wood of an ordinary razor strop.I stropped my razor in the usual manner and found N excellent yet simple brown stain this novel strop to be very efficient.- for wood consists of a saturated August Jeffers. solutionofpotassiumbichromatein Ivater.It needs no rubbing and leaves a brown satin -like finish, which cannot Decorating Polished Tools be produced by pigments.An excellent CONINIERCIAL-LOOKING whirled surface for applying a finishis left.- decorations on tack hammers. hunt- Eibra IVelsch. ing knives. Hat metalparts of guns, paper -weights, or anything of steel can (Potassium permanganate, used the be made by a drill press, a piece of cork saute way, is also esccIlent.-Editor.) AFTER SMOKING 818 Science and Invention January, 1930 Readers' Opinions and Comments Will Be Welcomed by the Editors What Our Jupiter's Light the Ouija Board's foretellings proved to be With every best wishfor your con- facts. tinued success, Editor,SCIENCE AND INVENTION : In the November issue of your splendid JAMES A. HANNAH, While reading some of the articles in magazine you acknowledged your belief Clydebank, Scotland. your magazine, a confusing problem arose, that our subconscious mind is the causative whichhas causedconsiderabledispute. (The number of pages in SCIENCE AND This we arc submitting to you for final INVENTION magazineissubstantially the determination. same asithas beenfor several years. Is the light that is emitted by the planet There has been 110 decrease in the amount Jupiter, its own light, or is it merely the re- of text space.Now, however a greater flection of sunlight? number of articles arc found within the Does Jupiter emit its own light, thereby cover pages.You may rest assured that makingitvisibleto the other heavenly should there he a change in the text matter Is dies, without the assistance of the sun's in this publication it will he in the nature rays? of an increase rather than a decrease in the MARTIN HERSH, number of pages. Hopewell Junction, N. Y. We thank you for your compliments.- EinToR.) (UNl recently it was supposed that the rapid changes of the surface markings of Headless Insects Jupiter were due to cloud formations and Editor, SCIENCE AND INVENTION : that the planet had to be almost red hot to I ant a regular reader of your magazine. cause such a rapid change. factor in the operation of the Ouija Boar(l. If I remember rightly you once published In 1914 and 1922 Dr. Coblentz showed What does that mean?Would like to an article about some scientists who kept that the radiation which comes to us from know a little more about this mystery. the head of a dog alive for a considerable REV. LourUNGER, time after it had been severed from the Hanitramack, Mich. body. Quite by accident I snapped the head of (There is no doubt but thatin many a fly from its body with a rubber band.I instances messages, supposedly delivered by was surprised to see that the fly's body a Ouija Board operator,foretold what continued to live for nearly twelve hours subsequently came true.These cases arc and every time it was touched the fly would pure coincidences. In many others the buzz around.I thought perhaps that you Ouija Board message was so perverted as might be interested in this fact. to make it fit the circumstances. SCIENCE JAMES SIMMONS, AND INVENTION magazine, as you un(loub- Fort Dodge, Iowa. tedlyknow,has astandingofferof $1,000.00 which it will pay to anyone whim (The further one goes down the evolu- will produce any readable message on an tionary scale of animals the more easy is Ouija Board, theletters of which have it to keep the bodies of animals alive, even been transposed by us and the operator, though the head has been completely sev- securely blindfolded.Up tothe present ered from the body. time no one has been able to produce even If one of the arms of a starfish meets one readable message. with an accident the injured appendage is Most oftheindividuals who operate cast off near its base and after a time a Ouija Boards do not know that they them- new one grows out.The body of such a selves are controlling the movements of Vie starfish can be cut in two and each of the indicatingdevice. Nevertheless,subcon- parts can regenerate the other parts that sciously they are doing so.It is this same are missing.The same is true of earth mind, so to speak, that acts when we arc worms. If the body of an earth worm dreaming. We are not consciously aware should be cut in two, no particular harm of the experiences through which we pass results. the planet is almost entirely reflected solar when dreaming.The same is true of a radiation, and he proved that the tempera- lxmafide Ouija Board operator.lie does ture of the surface of the planet Jupiter not know thatitis his own mind that is was near -140° C.Thisisjust about causing the movement of the indicating what might he expected if but little heat dial. planchette or other signaling means. comes up from the interior of the planet. -EDITOR.) The assumption then is that the atmosphere about Jupiter consists of permanent gases More Pages and the clouds might be condensed particles Editor, SCIENCE. AND INVENTION ofcarl,on-dioxideorother substances Every succeeding number ofyour which arefamiliar tous as gases, but monthly leaves me with a growing sense of which boil vigorously at temperatures even irritation against a feature that is more ob- far below zero.While Jupiter may be hot vious the more interesting your journal inside itis not self-luminous.-EDITOR.) becomes.I refer to the short distance between its outer covers and I would be glad -J The Ouija Board as no doubt would many other readers, if Editor, SCIENCE AND INVENTION : this one fault in an otherwise faultless pub- Many experiments have been made in I would greatly appreciate your informa- licationcouldberemedied. Youwill grafting the head of one insect to the body tionaboutthe OuijaBoar(l. Doesit better understandjust how highly your of another.These were described in past really reveal secrets, hidden events, or is it magazine is appreciated here when Ire- issues of this publication.However, the a humbug? mind you that Clydebank isin Scotland, experiment with the dog's head is the first You deny supernatural power (spiritual- and thatIfullyrealizethatalarger one that was ever made with an animal ism) in its operation; so do I.But on the monthly might well result illits increased consideredtobeso highlydeveloped. other hand many honest persons affirm that cost. -EDITOR.) January, 1930 Science and Invention S19

Questions and Discussionsof Readers Think General Scientific Interest The Faucet Problem More Dope for Inventors cup as an award? To a man of deedsa Editor, SCIENCE AND INVENTION: Editor, SI IENCE AND INVENTION: cup means nothing, but give him something This problem was presented to us by a As on old reader and booster ofyour he can do things with and his joy is party who could neither prove nor explain un- magazine I wish to pass on some advice if bounded; he is the most grateful ofmen. the answer to us satisfactorily. you will permit. Now, to get to the root of the bush I've There arc four buckets, each holdingan been beating around.Why nut start a equal quantity of water.This quantity is new series of contests to be held, say, twice unknown. a year in which all of known sciencesare Bucket No. 1is set under a faucet and to be represented,in their turn, and to takes one hour to fill. award prizes of worth -while valueto agree Bucket No. 2is likewise set under a with the nature of the contest held? different faucet and takes two hoursto fill. Of course, I'm going tosuggest a series Bucket No. 3 is set under a third. faucet of contests.The first concerns thatpeer and takes three hours to fill. of all sciences, one which has donemore Now if all of these faucetsarc turned than anything else in the worldto alleviate into the fourth bucket how long willit human suffering, namely, bacteriology. take to fillthis bucket? Suppose a contest is started,say, ne,t This is the way it was explained tous- September; allow me to suggesta tenta- Bucket No. 1 takes 60 minutes to fill; No. 2 tive list of conditions.If it were started -120 minutes; and No. 3-180 minutesor a total of 360 minutes for all.The individual then divided the total by ten. We are at a loss to sec where hegot 10, nor can he explainitsatisfactorily. He tells us the answer is 36 minutes, when all three faucets are run into one bucket, but Occasionally you publish a page of much we cannot prove that he is correct. needed inventions.I am sure your friends Miss JEssuF, L. GREEN, and patrons arc interested in inventions and MISS DOROTHY H. ROESE, many of them are capable of inventing the Noroton Heights, Conn. things that arc now dreams. If you would continue this sort ofa page (The answer as given is incorrect. Here every month I am sure many readers would is one of the easiest ways of figuring out appreciate it. thisproblem. Supposing we take360 Permit me to say thatyour publication cannot be beat for inspiration to the in September it would, under these condi- minutes as the lowest common denominator, am- tions, continue until September of the fol- using the other time intervals of 60, 120 bitious inventor. A Constant Boaster, lowing year. and 180 as the numerators. You will then L. F. RILING, For the first condition: find that faucet number one willfill six Chicago, Ill. A candidate must submit toa group of buckets of water in 360 minutes.Faucet eminentdoctorsandbacteriologists, a No. 2 willfill (The Latest Patents department of this series three buckets of water in publication always shows the ambitious in- ofwater -colorsincharacteristic the same length of time and faucet No. 3 fields of as many of the known organic ventor what otherinventorsaredoing will fill two buckets of water in thesame along popular lines and this page presents parasites and saprophytes as possible. interval.Therefore. 11 buckets of water (2)These shall be painted on a Bristol will be filled in 360 minutes or one bucket a series of rather good and unusual ideas. hoard of uniform dimensions, preferably of water will be filled by all three faucets In the Patent Advice department there five by four inches. with the circular field in 32 8/11 minutes or 32 minutes and 43.6 is frequently a series of questions thatare three inches in diameter. seconds. answered in such a way as to help the (3) average inventor. They shall be mounted on a blank They disclose the rea- sheet of loose-leaf notebookpaper, appro- sons for inoperativeness of some of the priately labeled. suggested ideas.It is not always easy for (4) They shall be accompanied by the an ambitions inventor to build an apparatus following information on a separate sheet. that would completely overcome the diffi- All possible material concerning theor- culties enumerated by the editor of that ganism e.i.When discovered.By whom. department.See the answer to the question Under what circumstances.Pathogenicity. on railroad crossing gates in this issue.- Methods of culture. Isolating.Animal EDITOR. ) inoculation.Chemical composition.Effic- acy of various methods of destroying and Suggests Other Contests sterilizing.General description. Editor, SCIENCE AND INVENTION: (5) To the candidatesubmittingthe I have been a reader of your magazines, most complete series a suitable prize will be awarded.I would suggest a micro- SCIENCE AND INVENTION and "Amazing scope, one of the hest to be had, costing Stories," for the past two years; in fact, from $450 to $500. ever since "Amazing Stories" appeared on This form can be used for various other the newsstands. It was through this maga- crafts andscience-,such as zine chemistry, I was introduced to SCIENCEAND biology. pharmacy. w.)od-working,astron- INVENTION. Since that time I have been omy, mathematics. physics, electricity, and an ardent newsstand subscriber.I have so on indefinitely. never missed a single issue. I have chosen bacteriologyas an exam- I can truthfully say that I have ple because it Another way offiguring shows that gotten is to be (I hope) my pro- faucet No. 1 fills 1 bucket per hour: faucet more enjoyment from SCIENCE AND INVEN- fession. No. 2 fills 1/2 bucket per hour and faucet TION than from any other magazine: how- J. G. Q., ever, there are some things that I consider Hospital of Rockefeller Institute, No. 3 fills 1/3 bucket per hour.Adding these together we find we get 11/6 buckets a loss of time to read, the model depart- New York City. ment, for example. (We would like to hear from other of per hour, or 1 bucket in the same interval The model department of time as indicated heretofore.-EDITOR.) isallright in our readers about the proposition outlined principle, but why must you givea trophy by J. G. Q.-Editor.) 820 Science and Invention January, 1930 Radio Star Viewed atNew Televisor RADIOGusives Televisionand This Receiver Has "DX" Appeal yES. it's a radio receiver that the good- looking girls are perched on-believe it or not !This large receiver was displayed at the recent radio shows to demonstrate that a receiver could be made to secure the finest selectivity and long distance reception. in spite of the many strong stations on the air and the closeness of the broadcast channels.It has four stages of tuned radio frequency and four stages of audiofrequency. Incidentallyithas a wave -length range of from 35 to 3,600 meters.The dials may be interlocked. MI SS FLORENCE SHEA. selected as the most beautiful radio star in America. is shown here xvith the new General Electric Company's Televisor, recently displayed at the Radio Fair in New York.This television apparatus is theresultofextensive experimentation and embodies all the improvements from the vast laboratory at this company's disposal. Several new features are included in this new apparatus.Six -stage amplification, a thirty -inch scanning diskand four large photo -electric cells comprise the essentials of this set.As you will notice, the set is more compact than the usual television set.The writer viewed this set in action and can say that it marks a decided improvement.The image obtained on reproduction was quite clear and about a foot squareinsize. Thisgreatlyenlarged image at the receiver is obtained by the use of a neon -crater tube placed behind the rotating scanning disk, which contains a spiral of lenses. Why Not Radio for Every Hospital? RADIOhas been a great boon to thetients' rooms with many different sets. sick, who have found a constantNow the Radio Corporation of America source of amusement and diversion inhas come forth with an arrangement listening in on programs.In large hos-whereby the radio reception in a hospi- pitals the greatest problem in connec-tal, hotel, or any other large building tion with this source of amusement hasNv ith a number of outlets can be con- 4 always been the necessary room for an-trolledfromacentralswitchboard. tennie and the cluttering up of the pa-This system employs only one antenna. has a choice of four broadcasting programs. and may have any number of outletsto the rooms throughoutthe building.The Mixer and control panel may be operated very simply and requires no expert manipulation. The volume may be controlled at will. as well as the program selection.The patient has merely to signify his like or dislike of a program. and by means of jacks. Aboveillustration similar to a telephone switchboard. any shows earphones, cord particular program of the four being isplugged of which receivedatthattime may besent intowallconnection leading to central through the wire leading to the outlet switchboard. in the patient's room.In this manner the problem of amusement in such institutions has been considerably simplified. January, 1930 Science and inrentian 821 PHOTOS, Every Nice Jail Must HaveRadio MUSIC LTITUDE INDICATOR How High? Asks the Flier. Here's the Answer °THE recent success of the U. S. Navy with the automatic depth -findingin- strument has prompted Leo P. Delasso of Los Angeles. California, to investigate the possibilities of such an instrument incom- mercial flying. He is shown in the picture below with his invention, which he callsa "sound frequency analyzer."The instrument which he hopes to perfect would automatically record on a dial the distance to the earth, a mountain or other solid objects for the information of pilots flying in the dark or fog.

SING SING, the great gray collection of buildings on the Hudson River, home of New York's lawbreakers, has recently installed one of the most elaborate systems of radio receivers yet seen.The entire arrangement is the work of one of its in- mates, an electrical expert, who is shown in the picture above in the central control room in Sing Sing.At the left of the picture is shown the commercial loopop- erated receiver.To the right are the two nine -tube amplifiers housirg six push-pull amplifiers. The first three tubes supply 21 loud speakers. the next three supply 30X) headphones,thenextthree680head- phones. and so on for a total of 2,300 headphones. The receivers are wired in multiple series and so arranged that ifsome break down the rest of the system %%ill continue tofunction. The system runs throughout the large number of buildings at Sing Sing.

Photos Radioed14,000 Miles, England to Australia, in Four Minutes ANEW radiotransmitter which sends photographs, maps, or illustrations has recently been perfected by Captain Otho Fulton.This system may be used on radio transmission,on wireless telegraphy. or over telephone lines. One of the features of this instrument, which has already been adopted inprac- tically every country in Europe for the sending of weather charts,maps. and the finger -prints of criminals, is that it is small and portable.The machine is nothing less than marvelous. needing only three and a half to four minutesto transmit a photograph-a photograph having been sent 14.000 miles in four minutes from England to Australia. At the right may he seen Captain Otho Fulton. perfecter of the machine, alongside of this unusual instrument. S.)) Science and Invention January. 1q3n Chicago Police Use Radio to Outwit Outlaws

ARDIO has become part of the present-day police force equipment.With the great increase in crime in the city of Chicago, officials of Station WGNoffered the facilities of the station to the police in order todemonstrate that radio could advantageously be employedin catching criminals. Police Cars ANUMBER of automobiles were equipped with radio receivers, the antenna being placed in the roof of the car.The controls of the radio set were locked onWGN's wave length.So successful was the radio service that it is planned to extend its use over the entire city.When a call comes in to the station, the programis immediately inter- The above illustration shows a microphone installed in abank rupted and the police alarm broadcast to theautomobiles, vault.Ilihen used in conjunction with an amplifier, the slight- which then proceed at a fast rate to the scene ofthe crime. est noise is made audible. In order to broaden the service begun by Station WGN, the Po- lice Department has obtained the use of the Naval Reserve Station NDS, which issituated on the north side of Chicago.In the near future it is planned to make the police broadcast on low wave lengths so as not to interrupt the regular broadcast programs and also to insure a certain degree of secrecy. Radio Watchmen A..1 alarm system, consisting of a microphone, amplifier and

-LOUD SPEAKER MICROPHONE

The illustration above shows a police car equipped with radio hurrying to the scene of a robbery after being notified of the crime from the broadcasting station.At the left is a bank vault radio installation, which promises to curtail any robberies in this direction. TO OTHER sages. consisting of license numbers of stolen cars, miss- K_SPEAKERS ing persons and other police information, were also AMPLIFIER received. TO POWER SUPPLY Several reports of the efficiency of radio as a police aid were recorded in the station logs during the month. speakers, is now being installed in several bank vaults.The In one instance a police boat received a call amid learned that slightest noise in the vicinity of the vault will heamplified a man with a gun had been seen going into a store.In 30 greatly, and, issuing from aloud speaker, will givewarning seconds the boat arrived at the scene and the man was ar- to the watchmen on duty. A linemight also be led from rested. Two men were arrested by the crew of another sta- the bank to the nearest police station. tion cruiser 19 seconds after the police had been notified that they were breaking into a store.Several instances of car stripping were reported to the police. and in three cases the Radio -Equipped Cruisers cruisers arrived in time to arrest the thieves.One of the CREWS of the radio -equipped boats of the Detroit Police runs was made in 60 seconds. another in 90 secondsand the Department have made 96 arrests (luring the month of third in 2 minutes. May, acting under orders broadcast from central stations. The cities of Detroit and Chicago have been pioneers in Since April 7, 1928, when the service was first inaugurated. the use of radio for man -hunting purposes.It is expected 748 arrests were made.These arrests required 114%2 min-and hoped that other cities will follow suit and equip their utes.The boats received 508 orders directing one or more police departments withradio sothatphotographs and to the place of the crime.Three aundred and nine Ines - fingerprints can be quickly radioed from one city to another. January, 1930 Scienceand Invention 823

THE set shown at the right.withchassis below. is the neutrodyne- pluscircuit.product of l'hilco. Itisan a.c. eight -tube seti including rectifier ). with tuned an tenna stage. three stag, of tuned radio frequenc U X 22t: tubes). detector usii,g a U Y227. two audio stages. two UX245 power tubesinsecond stage push-pull.

ABOVE is shown a new nine -tubea.c.receiver. manufactured by Brunswick.It has three tuned radio -frequency stages and a tuned detector, all using heater type tubes: a socket power unit using a heater type tube for the first audio and two UX245 tubes in push-pull for the power stage.A 280 double -wave rectifier tube and a voltage regulator tube complete the unit. NEW !RADIO SETS THE recenttrendin radio sets displayed at the radio shows in New York,Chicago,and Washington has been to the screen grid circuit, with -!m- phasis on greater selecti :ity and better reproduction.All of them displayedincabi- nets of unparalleled hea the selling value of aset seems to rest in great [art on the last quality.Here- with we show you some of the most prominent sets.

ONE of the latest screen -grid sets, an inexpensiveone. is shown above.It is the unitrad circuitproduct of Crosley. utilizing eight tubes, including three 224 screen -grid radio frequency tubes. A special feature of theset is a range control, which provides a greater control of volume with minimized distortion.The set is obtainable with or without cabinet legs.

THE above is the Colum- biaa.c.eight -tubeset shown with a portable phonograph and electric pick- up.It uses four heater type tubesi in the four r.f. tuned stages) and two power am- plifiertubesinthe audio push-pull output. Single dial control and complete shield- ing are among its features. A plug -on connecting cable MHIS Silver -Marshall set utilizes fourscreen -grid or a radio-phono link may 1. tubest one power detector and three r.f. tubes). be used. The feature of the The audio stage uses two power tubes in push-pull. combination is the selector Another feature of the set is the coupling of the first tuner. which permits instan- and second radio -frequency stages witha band selec- taneous tuninginof any tor which provides maximum selectivity. eight stations on the dial. 824 Science and Invention January, 193C Radio "Eye" to Guide Planes

EXPERIMENTS with a low power visual radio beacon are now being made, in an effort to aid flyers in finding flying fields during fog and at night. To make use of the new system an airplane need only to be provided with a small receiving set carrying an indicator which tellswhen the aviator deviates from hiscourse. These experiments are being carried on at Mitchel Field, Long Island. The airplane used in the experiments is shown. This plane has the new type vertical antenna. How to House Airplane -Cloth Speaker WilliamD.White,Chief Pr HE two photos Operator.is shown setting a I illustrate a novel course on the goniometerat method of enclosing Mitchel Field's new radio bea- the popular airplane con. It lays a course for planes clothspeakerina within five hundred miles. console. The speaker As the receiving indicator in isset inthe lower the airplaneis of the visual part of the cabinet type, it is not necessary for the and covered with an aviator to wear head phones ornamentalgrill and signal.: may be received work. The radio set withoutfear of interference from engine noises. This is placed in the upper device should be a great aid to both commercial and mili- part of the cabinet tary flyers. and is adjusted from The indicator may be installed on the instrument hoard in the top. Auxiliary front of the pilot, where it will be most convenient. apparatussuchas the power device and amplifier are placed Movies and Radio from One Console! behind the speaker. ir FIE diagram below shows how an attractive radio set Such an arrange- 1 and motion picture projector combination may be in- ment offers a useful stalled in the same cabinet.The radio set and loud speaker suggestion to the radio listener who ?referstheair- plane speaker to GROUND the dynamic type GLASS SCREEN \II'- speaker.In mak- MIRROR ingthecabinet AT 45ANGLE for this speaker it _ _ would be well to I 4 RADIO keep in mind that ; s- SET # it should be stur- 1 dilyconstructed PROJECTION OPENING to prevent para- ti *A sitic vibrations. 4 Parts of the set SPEAKE3.,-, 11 should also be mounted sothat MOVIE. theydo notvi- PROJECTOR brate.A phono- graphturn -table and pick-up can be easily mounted FRONT VIEW SIDE VIEW on the top panel, making a phono- may be any popular type.A novel use of a mirror -Ind graph -radio com- ground glass screen is made in the arrangement for project- bination.Excel- ing motion pictures.As is shown, the pictures are reflected lentqualityof from the mirror to the ground glass opaque screen.Radio reproduction will programs may be tuned in as an accompaniment to the resultwiththis picture being shown. Thus two modern inventions are com- arrangement. bined in one attractive cabinet. Science and Invention

Dry Rectifiers A. 1. This instrument is known as the (740)John M. Rogers,Schenectady, Potor and replaces the old method ofre- N. Y., writes: sistor-transformer arrangements, and the Q. 1. Will you please describe the dif- use of adjustable taps on the transformer ferent types of dry rectifiers now in use? primaries.This instrument is very sensi- Q. 2. Please give diagram of how to tive and in commercial form the windings connect the separate plates of such a recti- arc arranged so that any voltage may be fier to the secondary of the single trans- controlled in the output. former? It consists of four windings instead of A. 1. There arc two dry rectifierson the usual two: the primary, the additive, the market, the first is the so-calledcopper the subtractive, and the secondary wind- sulphide plate (which depends on the for- ings.The coils are so connected that the mation of a film by electro-chemicalac- flux paths of core windings No. 1 and No. tion) ; the second is the copper oxide type. seen diagrams in many of the service bulle- 2 are in the same direction and that the The latter does not depend on any chemical tins, but they are all rather complicated. flux path of core winding No. 3 is in the reverse direction. reaction for its rectifying property ;,there- A. 1. We have recently rim across avery fore, it probably will last much longer. At a predetermined low voltage point, The first copper oxide rectifiers to be the ampere turns of winding No. 2 should manufactured consisted of two discs per ele- TO BATTERY be such that the section of thecore sur- ment, a "mother" copper disc, a copper oxide OR rounded by this winding will be operating SPEAKER layer, and a lead washer.These rectifiers upon the upper knee of the saturation curve, when used in radio sets and for other com- while at this same voltage the flux in the mercial uses were very bulky, andcon- core surrounded by winding No. 3 should sequently some improvement was needed. 4 be balanced out. The Kuprox rectifier is the copper oxide i It is necessary in fulfilling this condition D .0 to take into consideration both the flux rectifier which is most commonly used at OUTPUT present.As shown in the drawing, in this generated by the primary, No. 1, which is column, the plate consists of the central in the same direction as that generated by "mother" copper plate enclosed by a layer - the core winding No. 2, and thereverse of copper oxide and metalliccopper.This flux generated by the counter E. M. F. of plate is a complete rectifying element and the secondary, No. 4.The flux generated Diagram shows 12 copper -oxide plateston- nected in series -parallel.

simple means of testing radio tubes in the -FLASHLIGHT-. MOTHER DISC 1 COPPER current issue of Radio.On the right is BULBS t'a. 2 PLATE seen a diagram of the testing apparatus. If G P the tubeisin perfect condition, lamp 3 BOLT,. should light on placing the tube inthe socket.Lamps 1 and 2 should remain un- / lit.If lamp 1 lights,it shows that the grid and filament arc touching.If lamp 2 INSULATING lights, it indicates that the grid and plate TUBE are touching.A simple and sure means COPPER OXIDE of relieving these situations is to gently

LAYERS tap the tube in the palm of the hand; this will often separate the elements. 3 REDUCED CROSS SECTION COPPER FILMS OF DISC Voltage Regulator "- FLASHLIGHT CELLS':-- Above illustration shows constructionof (742)LesterJ.Ochs,Tampa,Fla., elements of copper -oxide rectifier. writes : Layout of flashlight lamps, batteries and socket for testing radio tubes. Q. 1.I have heard recently of a power is only 0.25" thick.This rectifier is very transformer which is used as a voltage efficient, and does not deteriorate for a very regulator.Will you please describe it and by the secondary is in the same direction its actions. as long time. that generated by core winding No.3. The copper sulphide rectifier consists of Note,too, thattheprimarycurrent five separate and distinct parts; a copperor through winding No. 1 also flows through brass radiating plate, a soft lead washer, a portion A winding No. 3. copper sulphide disc, magnesium disc, and With these factors taken into considera- a lead washer.This rectifieris quite as tion, and the design made accordingly, at efficient in the quality of current supplied, low line voltage the flux generated incore but due to electro-chemical reactions, it de- winding No. 3 is balanced out andconse- generates in a very short time. quently there is no voltage drop across the A. 2. The best way, and, incidentally, the tapped section, No. 3-A, of winding No. 3. way these rectifying elements are connected The primary, No. 1. therefore has full line in commercial rectifiers,is in series par- voltage impressed across it.The secondary allel.The diagram of such a connection is voltage under these conditions will depend shownhere. Youwillnoticethat12 upon the number of turns and the flux Kuprox discs are used to obtain full -wave density of the core surrounded by winding rectification from the single transformer No. 2. secondary.The same connection may be At this point the circuit will show some used in the sulphide type of rectifier ex- regulating properties, even though the flux cept that two 8 element units must be used in the core surrounded by winding No. 3 to obtain the same output. be in balance, as the core surrounded by winding No. 2 is now working on the Bulb Testing knee of the iron saturation curve anda large increase in ampere -turns is required (741)JamesC.\Vilby, Minneapolis, - N2.1 for a small increase in flux density.Ad- Minn., writes: ded to this regulating action is the reverse Q. 1. Could you please tellme some Windings ofgraftageregulatortrans- fluxin the core surrounded by winding simple way of testing radio tubes?I have former. No. 3. 826 Science and Invention January, 1930

NOTE-INGDOING UNSIGHTLY 1sT Boy-What's a Jou xxv-Teacher, can quire of paper? bacteria see: Scientific TEACHER-Why do you 2ND BOY-Choir of paper? Oh. it must be one ask such afoolish ques- of those music rolls for a tion? player piano. -W ill iam JOI NNY-I heardthat Tindale. Humor some bacteria are cock -eye k cocci ).-M. Zykofsky. FOR ZOOMING AVIATORS YOU NEVER SEE A FISH GRAVITY DEFIED First Prize-$3.00 Gym CoActi- FIRST STU- Lift up your left DENT (,111 the legs and hold city) - What them straight are those things out infront of stickingout you. from thesides A freshman ofthatsky- held up his right scraper? leg by mistake. SECOND STU- This brought his DENT-Oh those right and his are mile posts. companion's left -Frank Holm, Jr. leg close together.The coach on seeing this ex- SHOULD ASK FOR CARRIER claimed: "And who is that galoot over PIGEON there holding up both legs?"-Juanita Itwasa coldFebruary morning Cunningham. and the sheriff had gone to the cell of "Light rays are refracted when they A VACUUMIN THE WRONG Mose Jackson who was to be hung the PLACE next day. enter or leave water.This property "For your last meal you call have shows that you do not see a fish where PHYSICS PROFESSOR -1 tyou should ::nothing you want and as much of it it is; and as you cannot see a fish where drop a lead ball and a feather from the as you want," said the sheriff."What it is not. therefore you do not see a fish top of a building at the same time, would you like, Mose?" at all."-K. Subramoney. which would hit the ground first ? "All believe Ali'd lak a nice water- STUDENT-The lead ball. melon," replied Mose. PROFESSOR -1S there anything that "But watermelons won't be ripe for ALLjokes published ho, would make both touch tile ground at 6 months yet," said the sheriff. .11for atarateof $1.00 each; once. "Ah kin wait, boss. All kin wait," re- $3.00 is paid for the best joke sub- STUDENT-Tie the feather to the ball. plied Mose eagerly. mitted each month. -Elmer Paulson. -Mrs. H. E. Chrisman. Jokes must have a scientific strain and should be original. GOLIATHS LEFTSPOT OF INTEREST Write each joke on a separate sheet TEACHER - Po - Did of paper and add your name and ad- Do peopleeat yoursongo dress to each. whale meat ? ,L) throughcol- Unavailablematerial cannot be JIMMY-Yes, lege? returned. Aram, they do. BA N (', - Not T AunER- quite.He took What is done a chemistry with the bones? course and only WELCOMED DEATH Jim MI.-They went asfar as The after -dinner speaker droned on put them on the the roof. andon. One(linerafteranother side of the plate. -Juanita yawned and nodded, one finally resting -Leo Packer. Cunningham. his head on the table.Leaning over, the chairman tapped him on the head A PSYCHIC PHENOMENON OUT OF SHAPE v,ith his gavel.The delinquent raised A manand womanaccidentally A man had just visited the zoo for his head a little. touched each other's feet under the table. his first time.Upon seeing a camel, he "Hit me again and harder," he said, "Secret telegraphy," said he. exclaimed,"Mybutthathorse is "I can still hear him." "Communion of soles." said she. warped." -Early L. Newell. -Mrs. H. E. Chrisman. -Frank Shymk,. Scienty Simon-Scientist

I'M GLAD ?NAT I WAS ABLE SCIENCE LESSON 1.0 OrSTsomeOF THAT 140 38 -rooGsreAs wa'e .. OH& FiNM TUNGSTEN FILAMEgr ANeLex- WISE 1 coqs..Dner RIG UO THISikome- TRiC euLisIS HEATED BY atscraic The CURRENT UNTILIT Rod LIGHT. REACHES -1-NE POINT OF wuire- OTWCANOe3CENCE. SHOULDANY AmtBe,pReseAr, THe 'TiktN WIRE WOULDBE C.nctocze.D ANDcomsumeD ALMOST r&ISTANTLY TO PREVENT 11MS ,A/FAIILNALL "I'MEA:1. 15 PUMO8D OUT °P THEeui-e, conarbocr AN Almost. PeQPecr vAcourm, OR Else IT is FiLt..E.0 wtn4 A14 wear GAS Luca AhntoGeAt January, 1930 Science and Invention 827

Change in Boiling Point at anelectrifiedrod always attractsthese Different Altitudes vanes, asitshould do on electro-static (2337)HaroldD.Johns,ElPaso, theory, unless some disturbing factor such Texas, asks: as a large amount of heat or light radia- Q. Is it true that altitude or depth pres- tion strengthens the normal movement of sure may be calculated from the lowering c e the radiometer vanes enough toovercome or raising of the boiling point of water? the force of magnetic attraction.To he A. This is quite true, and the method sure that the vanes were attracted by the used for calculating this is very simple. charged rubber rod, I performed thisex- The normal point of distilled water is 100 periment and found that there was nore- degrees Centigrade or 212 degrees Fahren- pulsion of the vanes. heit at sea level (760 mm pressure approxi- DoesElectric Charge Affect a mately). An instrument called the hypso- Radiometer Lead Ball or Feather Falls meter may beusedtodetermineany Faster? abnormal pressure shown by a change in ( 2339)NIi.s Rowena Klein, New York boiling point.This instrument shows that lity, writes: (2340) S. G. R..emer. Palto Alto, Calif., an elevation of 543 feet produces a change Q. Why does a rubber rod charged with writes: of I degree Fahrenheit in the boiling point frictionalelectricityrepelthe blackened Q. Do all bodies, regardless of weight, of distilled water. This instrument is only sides of the vanes of a radiometer, while it fall with the same velocity. for laboratory use, as itis quite delicate. A. This question is easily answered by The water used must be distilled, for im- the classical experiment of Gallileo in his purities would raise or lower the boiling vorkwithcompactbodiesofunequal point without there being any change in weight.Ile found that all bodies would atmospheric pressure. fall with the same velocity, if theywere of different weights but compact in size.If How Does a Frog Breathe? they were not compact. he found thata certain amount ofairresistance would (2338) Frank Chamberlin, Jersey City, enter into the experiment, and the bodies N. J., writes: would not fall with the same velocity. A Q.If a full-grown frog is supposed to feather and a lead halt fall side by side in be an air -breathing animal, how isit pos- a vacuum. sible for him to hibernate in the mud during the winter, or remain under water for any length of time? Why Steam Radiators Hammer A. The frog is enabled to remain under (2341) John Duffy. Pittsburgh, Pa., in- water for a long period of time for the quires: same reason that most amphibians can; Q. What causes radiators to bang and mainly that his lungs are not utilized under become very noisy:Is there any means of water in actual breathing.Much of the stopping this? oxygen used bythefrogistakenin A. This seems to he the universalques- through his skin.If one should dissect a tion at this time of the year, foreveryone frog he would find the lungs very small in knows of the nerve-wracking noise caused comparisontotherestofthevisceral by the radiator as soon as the steam salve organs.The thigh region of the frog is is opened.This is particularly noticeable particularly suitedfor the absorption of in the morning, after the radiator has been oxygen.Here the air filters through moist subjected to the cool night breezes.Itis membranes and reaches the blood stream. The radiometer is shown above with the caused by the steam coming in contact %skit If the skin of the frog becomes very dry, blackened portions of the vanes and alsothe cold condensed water in the radiator. he will suffocate, for the air will not pass the polished sides. When the valve is opened the steam rushes through a dry membrane: that is the reason in, meets the cold water and a rapid con- frogs usually select moist neighborhoodsattracts material like small pieces of paper? densationtakesplace which pushesthe for their summer singing-fests. A. The Crookes radiometer, which is the mostfamiliarform ofthisinstrument, consists offour mica vanes carried on cross -arms and the little mill wheel as it may be called revolving on a pivot.These vanes are polished on one side and coated with lampblack on the other.The glass bulb in which they rotate has practically all the air exhausted from it.When ether BLOOD waves pass through the glass, from some AERATED external source of heat or light, they strike THROUGH the polished surfaces and are reflected. SKIN If theystrikethe blackenedsurfaces,the heatis absorbed, and the temperature of the few molecules of gas left in the bulb is raised.These molecules of gas hit the glass and rebound, giving the vanes a rotating movement.When we received the question mentioned above, we concluded thatif such a phenomenon as our reader INCOMING WATER FROM mentioned had occurred, it was due to the STEAM CONDENSED VAPOR //ow a frog breathes under water is shown large amount of heat generated in creating The incoming steam meets the cold water above. The air filters through the moistan electrostatic charge on the rubber rod. and rapid condensation takes plate. membranes in the skin of the frog and thus For a final authority on the matter we con- reaches the blood stream. sulted Dr. E. E. Free, noted engineer ofwater violently against the sides of the New York City, and he gave us the fol- radiator, causing that clanking noise which Frogs arc able to endure prolonged sub- lowing answer: is known as water -hammer. mergence because the blood can be aerated It is not true that an electrified rubber One way of throughthe obviating the trouble is to open the steam skinfrom the surrounding rodordinarilyrepelsthevanesofa water. valve very little and allow the steam to Crooke's radiometer. On the contrary such gradually filter into the radiator. 828 Science and Inv, ntinn January, 1930 Latest Patents Notice to Readers: appreciable period of time elapses ANbetween the filing of a patent and the date upon which the patentisgranted. GOO During thisinterval inventors frequently r HANDLE move. We regret thatitis quite impos- OAR sible for us to supply the correct addresses of persons whose inventions appear on this page, nor can we furnish information about Boat Rowing Device when the product may appear on the mar- No. 1,704,074, issued toC. .4. Bilestine. ket.Attorneys who prosecuted the patent Ordinarily, when rowing, onemustsit cases can furnish the most reliable data. backward to the prow of the boat, result- Loud Speaker Copiesofpatentsareavailableatten cents each from the U. S. Patent Office, ing often in a collision or a miscalculation No. 1,718,354, issued to M. R. Hutchison, of direction.This novel invention permits Jr.The object of this cleverly designed Washington, D. C. one to face the direction the boat is being radio loud speaker is to provide a compact rowed.Intermeshing gears cause the rear- and comparatively inexpensive instrument Stage Device ward movement of the oars by the rear- with increased power and volume of sound 1;111 ward motion of complemental handles. The throughout an exceptionally wide range of illustration clearly demonstrates this prin- frequencies. This is accomplished by means I ciple.By pulling on the handles, the oars of a large number of eccentrically arranged are forced backward, propelling the boat horns,orair -chambers,increasingsys- forward. tematically in length from a common central opening to the outer periphery, giving progressive lengths for resonance. Fountain Brush No. 1,704,224, issued to John J.Sitkin. Cigarette Package A plunger projecting from the head of this brush forces the contents of the refillable No. 1,718,572, issued to M. .11. Marcus,. This prin- This package is designed to provide for the hollow handle into the brush. delivery of one cigarette at a time until the ciple can he readily applied to paint, shav- package is emptied. tape, made of, paper

No. 1,708,159, issued to Steuart S. Swoyer.This invention relates to a portable vertical platform, tobe temporarily set up just back of the proscenium arch in a theatre.Its purpose is to permit the per- or other suitable material, is fastened at former to run up itto do a somersault or one end totheinterior of the package, hack flop. Passes over and around the cigarettes, and has the other end projecting at the end of Auto Snowshoe the package provided with an outlet.Pull- ing on the tape bring a cigarette to the No. 1,699,430, issued to William J. Hein- outlet. rel. Often, when driving over snow -cot - ed roads, hard drifts of snow are en- ing, paste brushes and the like.Means is countered and the front wheels of the auto provided to prevent the return of the dis- are forced into the drift, with the result charged contents.The plunger is operated Airplane Toy that the rear traction wheels are unable to by the pressure of the person using the No. 1,722,922, issued to J. C. Johnson. brush. The two toy planes, mounted on the end of arms, when moving in a circular path, will swing outwardly under the action of centrifugal force, constantly remaining in a Boat Propellers horizontal position. They may be operated by motor -driven propellers or by a single No. 1,713,448, issued to William J. Roe. motor rotating the supporting stand. These oppositely driven propellers, having oppositely spiraled internested shafts and blades, are adapted for Use on what may he termed surface watercraft, such as hydroplanes, which, when their maximum speedisattained, have such a shal- /Vie draft as to practically skim or glide over the surface of the water. push the car through the obstacle. The These propellers snowshoe illustratedis designed to elimi- are designed nate this inconvenient stalling.This shoe to eliminate a is adapted to be supported under the front rudder with axle tolift the front of the car over en- itsresistance, countered drifts.Being placed a prede- ordinarilyre- termined distance above the ground, this quired when device will operate only when drifts are standard pro- encountered. .1 guide rib is provided along pellersare the bottom of the shoe. used. Ja111111ry , 93{1 Science and Invention s'

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RCA INSTITUTES, Inc. Dept. EX -1, 326 Broadwa, , York. N. Y.

ISPOMSOMOMY) Gentlemen:Please send me y vitt FREE 40 -page -book which illus- tratesthebrilliantopportunitiesinRadio anddescribesyour laboratory -method of instruction at home! RCA INSTITUTES,INC. Name Formerly Radio Institute of America Address Science and Invention January, 1930 You Can Make These A $ 1 0 0 Illuminated Table Decorations SHIP MODEL By Josef W. Von Stein (Continued front pose803) for $ 4 9 8 equipped with gelatin color screens, will Crepe paper of many hues is the chief be needed for floodlighting wall areas. material. Fashioned incountless ways. Most usefulforalltable decorations and combined with small amounts of col- and many of the room decorations are ored lighttheir beautyismagnified to thestringsofsmalllamps known as such an extent that practically all lighted Christmas treesets. Several types are table effects will be found to be merely available.One a 15 -volt lamp, is known adaptations of the familiar crepe paper as the series lamp which must be used forms to include lamps and wiring in their either with a small transformer or wired make-up. in series in groups of eight.The lamps Heavy cardboard is useful, not only in and sockets being very small, they loul foundationsfor some paper decorations. themselves admirably to table decorations. but also in making bases for the decora- Nevertheless, they offer somewhat of a tions to stand upon. disadvantage inthat the failure of one Fine spool wire and paste serve as the lamp extinguishes the entire group. binders holding together the wiring devices

Smallilluminated figures, with faces painted on the bulb lamps, can be used SANTA MARIA at all times. 25" High; 11" Wide; 27' Long You can puta beautiful Skip Model together in afew hours of pleasant Another type is known as the multiple and the paper decorations.Heavy cotton pastime. Christmas tree lamp.This 10 -watt, 110 - covered supporting wire is necessary where Let the World's Largest Builders of volt lamp, while slightly larger than the it is desired to have the socket stand up- Ship Models supply you withall the foregoing, may be burned singly or in right.Fiber candle husks, balloons and necessary parts cut to fit and ready to groups wired in multiple on a single cord. inflated rubber toys all have their places in puttogetherforthemodels,Santa They have the advantage in that any num- the general layout. Thumb tacks and pins Maria, Mayflower, or La l'inta. You ber may be used in a group, and the fail- are essentialstofestoon the room and neednot know anythingaboutship building to assemble one of these models. ure of one lamp in no way affects the table. If you have never seen a ship model other lamps in the decorative scheme. All these decorations are built directly you can put one of these models to- A third type of lamp, and one that will about the lamps, and the method of wiring gether in a few hours by following our no doubt be used more titan any other, is or assembling will he determined by the diagram and instruction sheets which the10 -watt,110 -voltlamp which was type of decoration. explain and show you exactly what to designed for decorative and sign service. do with each part.All you need isa Christmas Table Lighting small tack hammer to tap the parts in This lamp has a decided advantage over place-the diagram making itimpossi- the other types, particularly in cases where the garnishing of the Christ- ble for you to go wrong. These models the decorations are to be relatively perma- BESIDESmas tree, we are growing familiar when completed are exact in every de- nent, as it is designed for longer life than withtwinklingwreaths,candlelighted tail of the famous old ships they repre- the Christmas tree lamp. windows,festooned entrances, and even sent, and when completed will add a floodlighted exteriors.The play of imagi- distinctive touch to your home.We Papers and Accessories nation will produce fascinating effects for also have parts for the model for the Constitution and Flying Cloud at $6.98 ; materials out of which the actual the table far more original than the lighted THEdecorationsareconstructedconsist tree. all other models listed at $4.98 each. A center table decoration may be made High \Vide Long largely of colored and fancy papers.Oc- casionallyatranslucentneutralback- ofa 10 -inchhall -shapedwireframe La Pinta...... 26" 11"27"$4.98 ground, on which color effects can be built, covered with crushed white crepe paper. Mayflower 26- 10"30"$4.98 is desired, as in the case of lanterns for Through a small opening in the bottom is Constitution....25" 8"29"$6.98 inserted a string of red Christmas tree Flying Cloud.... .24" 7"33"$6.98 garden parties. A heavy grade of manila Models sent C. 0. D. anywhere in U. S. paper, oiled with boiled linseed oil, serves lamps, the entire lamp and socket being All foreign orders must be accompanied by excellently.The paper is pasted or sewn in turn forced tip- .ogh the paper wall so U. S. Money Order or Check. on a light framework of wood or wire. (Contin!, 'o!7'832) These prices are f.o.b.,Philadel- phia, plus a few cents postage. Write for our beautifulillustrated booklet containing photos andinforma- In AMAZING STORIES For January tion onall of ourmodels. BEYOND THE GREEN PRISM, by A. Hyatt Verrill.(A serial in2 parts.)Part 1. MINIATURE SHIP MODELS, INC. Few stories have elicited warmer praise from our readers than "Into The Green Prism," and the author has nobly answered the call forasequel in which, incidentally. Dept. LH-1 all scientific "flaws" are taken care of-so the author says. As all good sequelsshould 3216 Baring St. Philadelphia, Pa. do. this one far excels the original story. AIR LINES, by David H. Keller, M.D.,It is to be expected by this time that Dr. Kell& will Inject an original twist and surprise elementIn astory that deals with any subject. Miniature Ship Models, inc., Dept. LH-1 Aviation is no exception to this rule.And yet the future that this well-knownauthor 3216 Baring Street predicts for air travel is not beyond the realm of possibility. Philadelphia, Pa. WHEN THE ATOMS FAILED, by J. W. Campbell, Jr.Although Mr. Campbell is a Please send me thecomplete parts cut to new author and an extremely young man as authors go, he gives us aninterplanetary nt and ready to put together for the Model story of excellent merit, in which a goodly amount of interesting science is ingeniously interwoven to make a romance of startling plausibility.We predict a great following' for this author in the field of literature and particularly scientific fiction. I will pay postman plus a THE SWORD AND THE ATOPEN, by Taylor H. Greenfield.The opening of this story few cents postage. will carry a strong appeal to victims of that most miserable of our minor troubles- Please print name and address plainlyh hay fever.It is a tale dealing with the subject of chemistry-a subject which israrely avoid delay. treated, probably because it requires more definite knowledge, which must beobtained by actual study, than do most subjects. Name THE FOURTH DIMENSIONAL SPACE PENETRATOR, by Julian Kendlg, Jr.Here is another unusual tale dealing with that most baffling of subjects-the fourth dimension. Street or R. F. D This time the author employs the planetary atom in a most interesting manner, foraid in building the yarn.We can assure you ten minutes of fascinating reading. the City And several other stories,for which purpose we have added 16more pages to magazine. State January, 1930 Science and Invention 631 TheNevs11930"Models .DettaWoodworkin Units (Patented Jan. 1, 1929)

A -a-.;.--=mmegallio 1P11111111.111141111 "Delta" ElectricHandi-Shop A complete Motorized Workshop for craftsmen.including all necessary equipment for Circular Sawing, Wood Turning, Scroll Sawing,Sanding, Drilling, Grinding and Buffing. Practical Design Dependable Quality Plus Many Exclusive Features- that's what you find inevery woodworking unit bearing the Delta trademark. Craftsmen, artisans, farmers,mechanics-all who use wood in their daily labors or spare -time hobbies - are delighted with the sturdy construction,splendidefficiency, New "Delta', and moderate cost of Delta equip- MOULDING CUTTER ment. They appreciate keenly such exclusive constructional featuresas the I'atented Tilting Tables, Auto- matically -oiled Bronze Bearings, Heavy U -Shaped Lathe Bed, Circu- lar Saw Raising Lever in the Handi- Shop - the new Welded Steel Stands, Graduated Fence, Practical Rip Gauge, Graduated Miter Gauge, and the convenientarrange- ment, in the new Delta Jointer and Combination 4 -inch Jointer and Circular Saw Units, whichcan be 8 -inch Circular Saw Unit used with your motor, if desired. unmiiedconveniently oo welded steel - it Ispia. Cuts Over 50 Moulding Shapes chines can be used together or separate!, i or without motor. with With Only 4 Sets of Blades Ilich :quied blades produce over 10,000 8 -inch Circular cuts per minute ut 3500 R.P.M. Blades Saw Unit 10 Day Trial require no individual adjustment. Quick- mounted separately on ly and easily locked in position.Spe- sturdy. veldts! steel stand. Easy Terms cial guide fence. Unusually low price. v Ph or without motor. For complete details and full description of the new 1030 Delta line, sendcoupon IP OP 67- itr for FREE illustrated literature. Shows many items of interest to those who work lir rPC ®l with wood. You will learn, also, howyou can try any Delta equipment for 10 days under actual working conditions at our DELTA SPECIALTY COMPANY, Dept C-110 risk. Choice of three convenient payment Division of "Delta Manufacturinn Ca." plans. Mail coupon TODAY ! 1661.67 Holton St., rdilwaukee,Wis. Please send me FREE. ilhistrateil literature ileseribing 1930 model "Delta" 1Votalworking I tillsAla° details of 10 Day Trial Offer and 4 -inch Jointer DELTA SPECIALTY CO. I:asy Payment Plans. Unit Division of 'amp DELTA MANUFACTURING CO, practical design. 7 xi mord on stand. Furnished \ trash or without motor. 1661-67 Holton St. Milwaukee, Wis- Dept. C-130 o. Science and Invention January, 1930 How to Select an Oil Burner By Harry F. Tapp (Continued from page801) 550 gallons and 1500 gallon tanks are used, To sum up-firstselect only burners depending upon the size of the house and manufactured by nationally recognized or- delivery facilities. Naturally, if it is neces- ganizations. Investigate several as to their sary to excavate in rock, the costwillbr mechanical construction, keeping in mind greater, in which case the storagetank the possibility of having to replace worn should be as small as is practical for your parts in the future.Simplicity and relia- particular needs. bility are closely related. With the knowledge that the dealerisreliable in every respect, you can be assured the results will Initial Cost of Oil -Burner be highly satisfactory. EVERYONE is interested in the ques- (Next article will ct,:.er the installation tion of costs with oil as compared with of oil -heating equipment.) coal and gas.With figures itis possible to prove this question almost any wayde- sired. Extravagantclaimseitherway In RADIO NEWS should be materially discounted.It is safe, however, to assume for the purpose of for January, 1930 comparison that a good oil burner prop- Herbert Hoover, Jr.. Commercial Engineer, erly installed and adjusted will heat your with Western Air Express, tells what radio has Monte at a cost that is comparable done, and what itwill do, for the safety anthracite coal. As compared with the and development of commercial aviation. use of manufactured gas, at averagepre- vailingrates,thecostofoilwillbe Dr. Lee DeForest, inventor of the audion, EARLE LIEDERMAN, "The Muscle Beakel materially less. describes the manifold non -radio applica- ' Mudding." The cost of oil -heating equipment varies tions of this marvelous electrical valve. "I' Ith,' 1 ',durance." etc. with the type of burner installed andthe E. N. Pickerill, the flying radio operator, If You Were Dying To -night storage tank size and location.The cost tells what the Radio Marine Corporation will average between $650 and $750.The is doing to develop aviation radio. and you something that 0501111 air, you ten years cost of outside storage tank installationde- more tolive, would YOU take It?You'd grabIt.Well. fellows. I've got It. but don't wait till you're dying or It pends upon the conditions of the soilin Mr.B.Sleeper,President SleeperRadio won't sin you abitof goal. Itwill then betoo late. Laboratory, Former Chief Engineer Pilot Right rum is the time. Tomorrow or any day, some dis- which the tank has to be buried and local ease still get yOU and if you have not equipped yourself to rules governing the tank installation.Oil - Electric and Manufacturing Co., discusses tight it off, you're gone.1 don't claim to cure disease. 1 remote control of radio receivers. am not medical doctor. but I'll put you in such condi- heating equipment should not be purchased tion that the doctor silo ,turee to death waiting for you on the basis of econom,alone.It is nec- Norman Wunderlich, Chief Engineer, and W. to take sick.Can .1 ire a mosquito trying to bite consider all of brick wall? A 1 .,: essary that the purchaser F.Diehl,AssistantChiefEngineerof A RE -BUILT MAN the advantages that are obtained byits Radio -Victor Corporation show how lab- Ilike to getIli, , ,...I delight In getting hold use, and when these aretaken into con- oratory controlismaintained over radio of a min who ha. Ia.....i.vii down as hopeless by others. It's easy enough to li,, Ii a task that's tnore than half sideration any reasonable difference in cost parts manufactured under mass -production done.But she one the weak. sickly chap and watch him is easily justified. demands. 1.10,shunter.That's whatIlike.It's fun to me because I know I ran do It and I like to give the other fel- Most burners are sold today with a ser- low the laugh.I don't just give you a veneer of muscle vice guarantee period ranging anywhere These are but a few ofthe outstanding that Itoks good to others.I work on you both inside and leaders in radio who help to make January stiltI not only put hig, massive arms and legs on you. from three months to one year.At the but 1 build up those Inner mottles that surround your end of the service guarantee period, ser- R 4D10 NEWS one of the best-and most sisal orgens.The ,1,11real pep and energy. important-issues see have ever produced. Ur klt,,i . . ,'.ikon and the iourage to vice calls arc charged for at a rate de- tackle pending upon the location of the burner ALL I ASK IS90 DAYS in relation to the servicing station and to who ..inshape/Show me the man who ,..1....in.- and I'll make him eat a certain extent upon thenumber of burn- Ills word,.I'llput toe fulli,inch on your arm in just 30 ers installed in the community.Most com- Illuminated Table days.Yes. and two full Inches on your chest in the same length of time.:Meanwhile. Cm putting life and DM 1010 panies or dealers will provide a service sour old baekbone. And from then on.just watch 'eat The only Decorations srow. At the end of thirty slays you won't know yourself. contract at a flat yearly rate. You: whole body will take on an entirely different ap- additional cost to the owner is the price (Continued from page 830) !matinee.But you're only started.Now conies the real works. I've only built my foundation.I want just60 of any parts that must be replaced or slay- more 190 in IIIanti you'll make those friends of that the lamps are scattered over thesur- 11111S who think they're strong look like something the repaired. rat dragged In. The conflicting claims of the numerous face. About the sockets are then pasted A REAL MAN rival manufacturers and dealers make it red petals shaped like poinsettias to give When I'm through wills you. you're a real man. The the effect of the Christmas floWer bursting kind that ran proseIt.You will lie able to do things difficult and confusing to anyone attempt- that you had thought impossible.And the beauty ofIt ing to select oil -heating equipment. Claims from a white ball. Is you keep on going.Your deep full chest breathes in pure air.stimulating yourlilood and making you arc made, for example, thatbecause of su- LIGHTED FIGURES-With a head Nubble over with vim and vitality.Your huge. square large enough to conceal a small lamp, the houlticrs and your massive muscular arms have that crav- perior and revolutionary design features ing for the exeri Ise of a regular he num.You have the the "Peculiar" bunterisso much more figure may be of a size sufficient to akine flash to your eve and the pep to your step that mill make will use decorate the center of the table. sou admired and sought after in both thebushiest and efficient than any other thatit spriI world. 25 to 50 per cent, lessoil.Such state- It is more effective that the figures be TMr is no Idle prattle fellows.If you doubt me, make The small enough, however, so that the head me prove it.Co ahead.Ilikeit.I have already dune ments can be discounted 100 per cent. this for thousands of others and my records are unclial- efficiencies of well -designed and skilfully is composed of a bulb lamp on which the icnaed.What I have done for them.I will do for you. The socket rests on the Come then. for time filet and every day counts.Let this manufactured oil burners will probably not face is painted. very slay be the beginning of new life to You. vary more than 5 per cent.under equal top of a 6 -inch supporting wire, to which Send for My New 64 -Page Book' operating conditions. The skill with which the electric wires are bound with spool MUSCULAR DEVELOPMENT they are installed and adjusted will make wire.Two lengths of light -weight wire IT IS FREE bound with crepe paper and twisted. one Itwill 'bow what I have done for others and what I far more difference in the efficiency than ausdanter to do for you.It contains Is full -page photo- inherent features of the design. about the socket and the other about the araphs of myself and Tullio',prize-winning pupils I hare central standard, form the foundation for haloes!.Sane of these came to me as pitiful weakling,. The most important feature of design honk at them nowtYou will marvelatobelisplendid arms and legs.The figure is now ready to physiques.This book will thrill you.This w ill not ob- is to incorporate operating reliability and ligate you, but for the sake of your future health and hap- long life through the use of carefully se- be dressed in an appropriate costume. piness send today-right limv before you tutu this page. material. This togetherwitha BALLOONS-Lighting balloons is EARLE LIEDERMAN lected Fit a string of series Christ- 305 Broadway New York sound and efficient manufacturing organi- quite simple. Dept. 2701 zation provides a mechanical unit that will mas tree lamps with clear bulbs.Inflate Grasping the neck of the EARLE LIEDERMAN give satisfaction. the balloon. Dept. 2701. 305 Broadway, N. Y. City When considering the purchase ofa balloonbetweenthumb andforefinger Dear Sir:Please send mt. without any obligation on my part, whatever. a copy of sour lateit book."Muscular burner make sure that the dealer is finan- of left hand, with the right band force lwvehnonent:' cially responsible and mechanically compe- the lamp-dampened with water-into the the -pen end of the neck.The rest of the Name Age tent to properly install and maintain equipment.This can be done by inter- neck is worked over the bulb while base Street viewing a number of owners having the :Jlsocketremainoutside. city. sale (To be concluded) ilqese 01 Itesir print equipment you contemplate purchasing. January, 1930 Science and Invention S3 3 Thousands ofPositions Open Right Now for Motion Picture SoundEngineers

Salaries Due to the fact that radio and sound are Ranging so closely allied, men UP to with radio experi- 8200.00 ence are the most adaptable per WEEK

WE are in contact with chain anyreasonyouaredissatisfied theatres and manufacturers of DEMAND you being the judge Iwe will re- Inthe20,000 theatresthroughoutthe Sound equipment who desire thefund every cent you have paid. UnitedStatesand Canada. which nosy services of competent sound men employ approxitnately 50.000 projectioni,I,. as engineers, projectionists, instal- POLICY itis estimated that a very small per cent lation and service men.Our em- of this number are qualifiedtofillthe Our course on Sound Projection position as sound operator-.Many thou- irloymentdepartmentwillassist whichisprepared by the most sands of new men will have to be taken you in making aprofitable con-eminent authorities onElectrical into this field a- fast a, the many thousand nection free of charge. Acoustics will qualify you fora unwired theatre- are wired for sound as Profession whose place in the engi- the additions of -ound doubles the number GUARANTEE of operators required. 'This condition will neering worldissecond to none. create many thousands of positions at sal- Our guarantee insures you that ifAll of the available knowledge of aries up to $200.00 per week. you enroll as one of our studentsthe art and the underlying funda- The tuitionforthesecourses isvery and take advantage of the many mental principles of sound are given reasonable and is payable in easy install- opportunitiesthat your member- ments as you study.Al,o you have the to you in an every -day, plain -talk added convenience of studying at home in ship entitles you to, your increased language,aswellas two weeks' your spare time.Fill out and mail the income will pay the tuition of thepractical training in the operation, coupon below today for special scholarship course many times.We uncon-servicing and installation of Sound proposit ion. ditionally guaranteethatifforEquipment. Mail Coupon for Free Information

PROJECTIONIST IPROJECTIONIST SOUND INSTITUTE, P. 0. Box No. 28, Easton, Pa. x.N. I Gentlemen: SOUND Please send me, by return mail, full details of your Special Scholarship Prop- osition on Sound Projection.

INSTITUTE Name F. A. JEWELL, Gen.Mgr. P. 0. Box No. 28, Easton, Pa. Address City State I ------Science and Invention January, 1930 The City of Tomorrow What will you By H. Winfield Secor (Cominued from page 787) trees. Surely M. Le Corbusier is, some section of a city, one of the remedies is be doing one year of us might think, far ahead of his time; to blaze a new trail across the congested but aside from a few practical visionaries area at that section and open up a new wide from to -day? in this country, such as Mr. Harvey Wiley boulevard, even though many blocks of Corbett. the writer has certainly seen but buildings haveto be removed, for only very little in the proposed designs for fu- in this way can Nye make some kind of Three hundred and sixty-five days from ture citiesNVIIIC11 can begin to approach a fresh start towards simplifying the main the remarkable and logical schemes illus- line of traffic. now-what? trated and describe(' at great length by If some genius does not soon find a radi- Will youstill be struggling along in M. 1,c Corbusier. To read his descriptions cal solution for handling automobile traffic the same old job at the same old salary and stifflyhis illustrationsislike taking in the large cities like New York, itwill -worriedaboutthefuture-never a post -graduate coursein super -architec- shortly come to pass that the number of quite able to make both ends meet- ture. taxis will be curtailed by law. and also standing still while other men go ahead? Le Corbusier is an architectural surgeon, the workers will have to stop using motor- so we might term him, and to rectify the cars and go back to the subways.Did One year from today will you still be difficulties in which our modern cities final you ever stop to think of the vast amount putting off your start toward success- themselves, due to intense traffic conges- of space and also thefuel wasted each thrilled with ambition one moment and tion and many other undesirable features, day to carry one person to work by auto. then cold the next-delaying, waiting, itwill he necessary to perform in many The average car occupies 160 square feet fiddling away the precious hours that cases undoubtedly some real drastic sur- on thestreet. One man needs or gets will never come again? gery, as pf flitted out by this French author- abomt 2 square feet in a subway car.If ity. inotherwords,iftrafficisex- he drivesan autoheistaking up a., Don't do it, man-don't do it. tremely severe and congested in a certain tolleh valuable city space as 80 men should. Thereisnogreater tragedyinthe world than that of a man who stays in the rut all hislife, when with just a BookReview little effort he could bring large success PREHISTORIC MAN, by Keith Hen- RADIO TROUBLE -SHOOTING, by within his grasp. derson. Stiffcloth covers.6 x 8 Enno R. Haan, E.E.Soft, flexible Make up your mind today that you're inches. 272 pages. 102 illustrations. covers. 6 x 9 inches; 328 pages, pro- going to train yourself to do some one Published bvE.P. Dutton & Co., fusely illustrated.Published by the thing well.Choose the work you like New York City.Price. $3.00. Goodheart-Wilcox Co., Inc., Chicago, best in the list below, mark an X beside In a vivid and picturesque style, the author Illinois.Price. $3.00. it, mail the coupon to Scranton, and tells the story of man's ascent through the The author in preparing this valuable book without cost or obligation, at least get prehistoric ages.Nothing more fascinating on radio, has treated the subject with a view the full story of what the I. C. S. can do Or interesting has been writtenal tthe to assisting the repairman, as well as show- cave dwellers. the beginners of tribal cus- ing the layman how lie can do his own re- for you. toms, dress, and beliefs.The text is further pairing at home.The book deals only with enriched by a number of unusual illustra- radio troubles and their remedies, and shows INTERNATIONAL CORRESPONDENCE SCHOOLS tions. As one turns the pages he takes a anyone exactly whatis wrong with the re- Box 6205-F, Scranton, Penna. educationaljourneyintoman's ceiver and how the trouble may be corrected. Without cost or obligati., please send me n copy of delightful your booklet, "Who Wins and Why." and full particulars prehistoric past. The subject of trouble -shootingistreated about the subje(t War, at,. il I Moe marked -X: in a practical manner with definite instruc- TECHNICAL AND INDUSTRIAL COURSES JOINT WIPING AND LEAD tions and ahost ofillustrations, showing fiElectrical Engineer nArchitect Electric Lighting ii Architects' Illueprints WORK, by William Hutton.Flex- how to test the various components, how to Sfechankal Engineer 0 Contractor and Builder 51/_/$ x trace trouble and remedy it, and most im- Mechanical Draftsman 0 Architectural Draftsman ible fabrikoid covers; size Machine Shop Practice ['Concrete Builder inches.90 pages.116illustrations. portant ofall, how totakecare of the Railroad Posit ions 0 Structural Engineer receiver properly, in order to eliminate any Gas Engine Operating 0 Chemistry 0 Pharmacy Published by Scientific Book Corp., Civil Engineer 0 Coal Mining(? Automobile Work further trouble.Free from any theory on Surveying and Manning f !Aviation Diginex New York City.Price, $1.00. Plumbing :nal Heating 0 Agriculture and Poultry the subject, the contents are based on actual Steam Engineering 0 Radio LI Ntatheniaties This valuable manual has been prepared practice. Trouble is bound to arise sooner BUSINESS TRAINING COURSES so that illustrations of the actual work ac- or later eveninthe best of instruments. Rosiness Management Advertising companying the text and take the place of Industrial Management 1}:nglisli and the author has foreseen this in Radio Personnel Management fl Business Correspondent* personal instructions in joint wiping of lead, Trouble -Shooting. Traffic Management liShow Card and Sign copper. and brass pipe. \Vhen preparing Accounting and 12.P. A ' Lettering Coaching ristenn,:r.phy and Typing the material, the author kept in mind the Coat Accounting r Sercire AEROBATICS. by H. Barber, F.R., Bookkeeping I!Railway Mall Clerk needs of the inexperienced plumber, and he Salesmanship I 0 rade School Subjects has consequentlyexplainedeachstepby Ae. S.. M.I.A.E.Stiff cloth covers. Secretarial Work I 11101 School Solder's Spanish 0 French L Illustrating 0 cartooning means of photographs, so that the mechanic 8x 10!3,i inches; 78 pages. illustrated. in understandingit. Name Will have no difficulty Published by Robert M. McBride & The book also contains numerous hints on Co.. New York City. Street Address lead work, the care of solder, preparation of In Aerobatics. Captain Barber has present- parts, the handling of lead pipes, andthe City 'state ed a complex subject in such a way as to use of the right tools. make it thoroughly readable and understand- Occupation able. The book should prove valuable to If you reside in Canada. 1,04 Ihistrfollp011to the Iniernet- STAIR BUILDER'S GUIDE. by Mor- tional Correspondence Itehools Canadian. Limited, Montreal students and instructors of flying particularly ris Williams.Flexible fabrikoid cov- because of its excellent illustrations, which LEARN CARTOONING ers, x inches :259 pages. 358 show clearly in consecutive detail each of At Home- In Your Spare Time Published by the Scien- the different en olut. sin aerial acrobatics. The famous Pleture Chart. Nietliod illustrations. of teaching original drawing tificBook Corp., New York City. Part one, which is called Elementary opened the door of success for hun- is a lucid explanation of the essential ele- dreds if beginners.Whether you l'rice. $3.00. think you have talent or not. send ments of flight instruction from the moment for sample chart to test your abil- Stair building differs from other branetes ity and examples of the workit of carpentry;itis a science whose funda- the prospective student enters the plane until students earning from Sf.0 to 1300 he becomes a full-fledged pilot.The mechan- per week.Pira..er mate your nor. mentals liein problems of plane and solid THE LAN DON SCH OOL geometry. This book explains the simplest ical control of the machine, straight flying, 1160 National Bldg., Cleveland. 0 method of the art in its present stage.The stalling. gliding and landing, are fully de- Part Complete 110 -volt Elec- constructionofstraightflights,platform, scribed in language for the lay reader. ELECTRICtric Light Plant.Ideal cylindrical and elliptical stairs is dealt with, two explains the more advanced aerobatics, for Farms, Camps and and the theory and practice are explained so such as looping, spinning, rolling, the falling LIGHTS Summer Homes. can leaf, the cartwheel, and the like.The book ANYWHERE thattheaveragebuildingmechanic 3130' readily understand them.Examples of work also contains a glossary of technical terms Runs 'household appliances.In- from the simplest to the complex forms are and a number of advisory hints which will yourself.Wiring. Fix- greatly aid in turning a raw pupil into an stallit also included.Carpenters and those engaged tures and1.aniusfor 7 r01,11), much expert pilot within a short time and with $17.50.W ritefor circular. in building will find in this volume a D. W. ONAN & SONS. 180 looked for handbook of exceptionalmerit. the greatest margin of safety. Royalston, Minneapolis, Minn. January, 1930 Science and Invention 50,000 PeopleHave Read

this DaringBook THE BIBLE UNMASKED JOSEPH LEWIS What's in your Bible?You may believe that you know every line of it.But do you? Read this amazing book by JosephLewis, and like thousands of othersyou will rush to your Bible to find out whether thestartling facts he reveals have been hiding in itspages where you never dreamed they could possibly be.

Was $2.50 -Nowonly Partial List of Si Chapters "THE BIBLE UNMASKED" know why when pni read the .thraniand Sarni

1- is one of the most amazing partiallist of chapters. "sporting," or, !wailI.111111 books ever published.One fa- 11i. %S ifeIteloehiolo mous critic who saw it said: "It Mail Coupon at Once Incest, or, Lid mod Ili is the most daring exposure of These a hn, incredihic stories naught er% modern times."Other critics have been taken word for word Jacob, Leah and Rachel who saw advance copies actu- outof theBible. Their true Joseph and %%De ally begged Joseph Lewis not meaning,theirtruesense,is to print the hook.But the au- revealed to you in "The Bible Judith and His Daughter- thor insisted that the TRUTH Unmasked." You will be startled ito-lan Tamar The DID. Chapteror be told, and not a line or word and amazed.But you can never Judge. - forget was omitted or changed. therealtruthas you Kim/ Daiil of Israel and And itis for this very reason now see it exposed for thefirst iii,%A Ives that more than 50,000 men and time. Tioe snot, of Huth Thousandsof women haveacclaimed"The people have Kingsot andIlls JOSEPH LI WIS Bible Unmasked" as one of the gladly paid $2.50 for this darinc book. But for a short time only. most valuable books they ever and while The Hook of Esther read. They found facts which thepresentsitind The ew Testament Read These made them exclaim in wonder, lasts, YOU MAY GET IT AT The Virgin Hirth,for Enthusiastic "Can THAT be in my Bible?" THE SPECIAL REDUCE]) Mao. the 11013Ghost. Itmade them hurry totheir PRICE of only$1 plus only Joseph and Jesus Christ Endorsements 15c 'The pastors and priests for ex:dona- forpacking andmailing. The Itible Flom:Asked' lgo1 a brilliant silod daring tions. charges. Accept this big sav- to sl, Luke fcatofhonestscholarship ... every thinking man and That is why YOU ALSO will ing while you have the chance. Elisabeth, AngelCalorie! .moultwillappreciato,Its want to read this amazing vol- Readthishookthatstartled and Zacharias. or the crent merits." 50.000 people. 'seduction ofI.:D.4,1.4h ume. You willdelightinits Mail the COU- According to the Gospel -William J. Fielding. P( ) at once. of'st.Luke Celebrated Author. dynamic exposure ofthi in gs which perhaps yon never Freethought Press Asse. .Jesus and The Sinner "If thereligionistswill dreamed were in the Scriptures. The Creed of !Science r.aol Mr. Lewis 1,1111k.it Witt Dept. A-4, 250 W. 54th St., N. Y. I. them good. Ian,par- licularlypleased:Indim- pressed bythetelling way A Challenge to the World inwhich.tr.1.1WiS SPECIAL $1.00 OFFERCOUPON 111. 1111.1l1111 quota- This indomitably daring book The 1 re,ihoug litPress Assn.. Dept. .1-I tions." isachallengetotheworld. %% listreet, 11,-1.. -Rev. A. Wakefield Staten, Ministers must readitto de- .1., ..1.11 1-111, "If yon care to read about fend themselves. Religious be- our untique bookloaner. conta.ning floeothersideofthepit - moon cloth. at the special price of o ore.-taw nun,.I aimusk..n. lievers will be shocked at what charges. presents it." they have hitherto blindly given -The Bookman. to their children as examples of :Came "1 ...Idol easily get lip and morality and honesty.Think- .1,1,1r. t for Mr. Lewis without ing men and women willbe ...... roach effort." happy to welcome thislatest -F.douard Kelcigh. step of advanced thought. rity Palne and Bob In. So great has been the demand A special eonoldnatIon otter of Mr. 1.. I.1,rochoores."Lin- attackedtheItible coln the Freethinker." "Franklin the PI ectbinkor, ..to the groomd thatitwas for this book. and so widespread mon the Freethinker." together with a copy of Mr. Lewis' eloquent incredibleashistory. 11r. the controversy caused byits radio. addresses 1111"Lincoln the Soldler' an.1 -.terns from 1.cwis olcootincesitashie will be sent for only 5ac additional. I lige,- moral in its publication, that it is now in its souare and add 7.9e to your remittance. If ranted, put X in - Nca, York Run. eighth large printing to satisfy the insistent requests.You will 1-1 Check this box If you desire hook sent r. n. P 336 Science and Invention January, 1930 Making Scissorless Silhouettes By H. H. Dunn (('ontinued frnfn page 807) motion -picturesinthestudios, andstill measuring to the screen, instead of to thi pictures from one of them-a screen ver- outer surfaces, sides or edges of the per- sion of "Mother Goose" --are shoat here- sons or objects to he pictured.Size of the with.But the maker of silhouettes in the aperture and time of exposure vary with home needs no such expensive prepara- the character of thelensused, and are tions..\ screen of white cloth or tracing matters which can be determined accurately paper, sufficiently large to cover completely only by experience.The writer has seen a door or full-length window, is the only some veryfinesilhouettes made with a requisite, aside from the camera.Lacking hand camera costing $2, in which the ap- A Bigger Job other material, an (ordinary sheet will serve, erture was the smallest available and the though the best screen is eight by ten feet time the ordinary "instantaneous" release and You're the Maninsize,so asto coverfullyallspace of the shutter. probably about one -twenty- Are you hunting a bigger job, or does the biggerthrough which light may enter. fifth of a second.As the quality of the job hunt you? Why waste priceless years at routine The door or window selectedshould lensadvances,thestop may be made work, when you can acquire at home in a compara- smaller and the time increased to the point tively few months the specialized knowledge forface to the north or south,so that the which big firms pay big money? Thousands of mensunlight comes from the side, rather than where thefairytracery ofafinefern have greatly increased their incomes by home -directly against the screen, asit would if leaf becomes literally etched against the study business training under the LaSalle Problem white background of the screen. Method. Let us show you how you can do just asthe latter faced cast or west.Care also well or better.The coupon will bring you complete must be taken that the screenis drawn In such pictures as those described, all information, together with details of our convenient tight, and thatthereisno)wind heavy motion must be stopped :thatisto say, payment plan; also your free copy of a remarkable the one or several persons in the picture book-"Ten Years' Promotion in One." Make yourenough to distend it, or make it flap about. start toward that bigger job today. Holeslarger. thanone -thirty-secondof must remain perfectly still. No matter how - -Find Yourself Through LaSalle!- - -an inch will admittot() much light and LaSalle Extension thus spoil the picture.If possible,itis University best to have no holes of any size what- Dept. 1384-R Chicago er in the screen. though the latter can- Please send me full infor- not he coated with shellac or other material mation regarding the course to"fill" such (openings. and service 1 have marked with an X below.Also a In making silhouettes by sunlight, the copy of "Ten Years' Promo- work should be dome before ten o'clock in tion in One." all without the morning. and after three o'clockin obligation to me. the afternoon, so that the light conies from 0 Business Management: Training for Official. Man- agerial, Sales and Departmental Executive positions. one side. rather than from directly over- 0 Modern Salesmanship: Training for position as head.North or sunlit of the Temperate Sales Executive. Salesman, Sales Coach or Trainer, Sales Promotion Manager. Manu;acturers' Agent. Zone. these time limits vary, but in gen- Solicitor, and all positions in retail, wholesale or eral, the more horizontal the sun's rays, specialty selling. the better the result.The secret of mak-

Higher Accountancy: Training for position as Audi- tor, Comptroller. Public Accountant, Cost ingsilhouettes,eitherthe"stills"now Accountant, etc. under discussion, or motion pictures. to be o Traffic Management: Training for position as Rail- road or Industrial Traffic Manager, Rate Expert, described later, is that all light must come Freight Solicitor, etc. from the back of the subject. that is, from 13 Law: LL. B. Degree. bchindthe screen, whether it be the sun- O Banking and Finance: Training for executive posi- light through the open door or window. tions in Banks and Financial Institutions. Prramount Pletureo CI Modern Foremanship: Trainin y for posit ions in Shop orthe ci n111.4)11(2;1 electriclightofthe Management, such as that of Superintendent, Gen 2dslightly different silhouette, showing the eral Foreman, Foreman. Sub -Foreman, etc. si tubi. O Industrial Management: Training for positions in To accomplish this result, all light save effect of adding extra scenic properties to Works Management, Production Control, Industrial Engineering, etc. that which comes inthroollyhthe screen. the picture and giving more life to the subject.Real surprise shows in the face of PersonnelnneinarManagement:iu Training positionof mustbe excluded from the room in which l l RelationsManager. beautifulDoris seesthe Employment Manager, and positions relating to the picture is loving made.When this has Dill when she Service. been done furniture, plants. or any other "four -and -twentyblackbirdsbakedina n Modern Business C pondence: Training for Sales or Collection Correspondent. Sales Promotion objects may be placed in the front of the pie." Manager, Mail Sales Manager, Secretary, etc. screen with the person or persons to be in Stenography: Training in the new superior short- hand, Stenotypy. El Railway Accounting photographed. and no objectinfront of good the lens, or how short the time of n Railway Station 0 Effective Speaking. the screen will east a shadow on the white exposure, the slightest movement will re- "'" Management. 0 C. P. A. Coaching. and light -filledsheet. (Me rigid ruleis sultin a "blurred" picture.Thus. plants 0 Expert Bookkeeping.0 Commercial Spanish. that all persoins, animals. or (objects to be placed against the screen must be given 0 Business English. Stenotpy. silhionetted must beatthe same distance time to become absoolutelystill;animals El Commercial Law. El Telegraphy. .from the screen.This distance should be must be taught to, maintain their positions, o Credit and Collection Correspondence. as close to the sheet as the largest object and,usually. children rehearsedintheir can lee placed. though it is best that nothing parts in the picture. Name touch the screen at any point. UntilDyar discovered this method of With his "picture" so) arranged, the amusing the lens, a silhouette bad been con- Present Position ateurphotographer setsup hiscamera. sidered as capable of presenting only a squarelyinfront of the screen, andat "flat"picture. of two ditnensions, length Addreoo such distance aswillmake thesizeof and breadth. By the skillful use of a hand- negative desired.Usuallyitisbestto inirrOr,lloWeVur,thethird (111111C11S1011- make the outer cokes ofthe screen the thicklIvSfi-may he expressed.In the orig- CHEMISTSlimits ofthe picture. though the writer inal this was done very successfully in the Chem Sup- has seen some silhouettes in which a dark picture ofthe "four and twenty black- : Clo al-.In frame of wood, or card -board. was placed birds baked in a pie." presented herewith. ,1 -vient itirkook-all around the screen. giving the resulting The originalshowsvirtuallyathree- toi Clays Stilla. ilki.trated.picture the effect of a large and rich paint- quarter portrait of the young woman, with iPv of flak 1 qt. Complete $5 ing in black and white. much of the front of the face and neck LABORATORY MATERIALS CO. thephotographerisworking with presented as in a regular portrait, yet still 625 E.,.t 71st St. Chicago, U.S.A ;t focusing camera, he usesthe ground inthe black and iyhite of the realsil- glass just as he would in making any other houette picture.If he has a hand camera-placed When using the mirror for this purpose, AVIATION of course on a tripod or other solid support it shottld be held at one side of the screen, InformationFREE-he niust meastire the distance carefully, so thatitcatches and "throws" a little- Sen.us your name and address forfullinformationre- after locating and "sizing" the image in the and only very little-of the light passing gardingtheAviationand Airplane business.Fendout about the many great opportunities now open and how we view -finder. Ifthe distance requiredis, through the screen from the outside.Such prepare you at home, during spare time. to quality.Our new book "Opportunities in the Airplane Industry- alsolet us say, ten feet. then he nuist hart' the a light beam must be carefully controlled, sent freeif you answer at one, lens exactly ten feet from the persons or so thatitfalls only Nvhere wanted: that it AMERICAN SCHOOL OF AVIATIONobjects in front of the screen. not an inch is not too heavy; and that the mirror casts Opt. I -12 111,1i ?panAir.. CHICAGO more or less.l le also, must guard against no shadow anywhere on the screen. January, 1930 Science, and Invention 83; -%. \

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Se reen Book Science and Invention klI'st Kull monthit I.1 it:reader; the bed 'mole For the *tide -Intake family that omit: to kr,is up novel of the monthtotcomplete look length form. fullvft,. ..,yoneIntel- oithIlselisted developmentsin,irtsce and es - ,led In ,,. ,,. o tiltillustrations takvodirectfromthe 111011e II, trailer oil' 'situation. WrittenInnonderlotivaltavola:se. learn !piss. it -elftoorthat'vast $2.111, Inanybookstores. it apilotruutrulshi. i10,the Moto! brings its readers a liberal eclueationit.the field; T11011Cii S,sock.:101,1t 11111- .10It/hel/111e .so leis,.screengossip, movienetts;full- ofradio, vi/e graimeposte:titsofthe electricity. octal lot,, 1.111Velfir). auto- filer; low to build model air craft: how to build a stars, andseveral motive 111P111.111.1, television,photography.them shorter moth,arealsoIncludedInvarhI, -or. istry. etc. glider: and .lute's:of other pravtical.helpful bin Itevtilar price $2.:.it per year; special !WHINY ill ire Iltutilreils of Illustrations.Regular price of inf.wmatiollfortyas iationrettlmsla-tshould $2.81' perrat; special holiday price $2. no, know. Itegular $2.711 per year; sitevial holiday prim. P2.01). Radio News Plait) Talk The world's great, -.t folio magazine. Eve -p new For the development, Idea or invention that affects radio Is person oho Isn't afrAlil to rail here illustrated and described. a made a spade. It prints the truth about vital The Indile stories toplesfruit 111,11,ControltoProhibition;from of the big broadcasting stations. how to tell a good Psycho -All. b' -it 10Public Morals; from Art and loudspeaker from a had one. how to save money in Selene to Ntet.PhYsies and Politics.Shaw. Durant, servicing your set.all about the new sets that arc Ludolg and Brumfield and other equally coining out. are some of the feature; covered oitiths fathom+ men are momg the contributors. Itspage,. Itcailarprice $2. In per year: special Regular holidaytrio $'_!ott price $4.00 per tear; special holidayprier$:I.00.

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lot i; nntrrss 0 INN IMM um umAID MI OM INN MI NM Ell NW MIR MI January, 1930 838 Science awl Invention PATENT ADVICE INVENTORS CONDUCTED BY JOSEPH H. KRAUS In this Department we publish such matter as Should advice be desired by mail, a nominal is of interest to inventors and particularly to those chargeof $1.U0ismadeforeachquestion. Protect Your Ideas who are in doubt astocertain patent phases. Sketches and descriptions must be clear and vs Regular inquiries addressed to "Patent Advice" elicit. Only one side of sheet should be written oil. cannot be answered by mail free of charge. Such Send for our Guide Book, HOW TO inquiries are published here for the benefit of all NOTE:-Ilefore mailing your letter to this de- GET YOUR PATENT, andEvi- readers. If the idea is thought to be of importance, partment, see toitthat your name and address dence of Invention Blank, sent Free we make it a rule nut to divulgeall details, in are upon the letter and envelope as well.Many order to protect the inventor as far as it is possi- letters are returned to us because either the name on request.Tells our terms, meth- of the inquirer or his address is incorrectly given. ods, etc.Send model or sketch and ble to do so. description of your invention for IN- SPECTION and INSTRUCTIONS wings for increasing the speed of flight FREE. TERMS REASONABLE. Automatic Railway Safety Gates after the plane has left the ground and in BEST REFERENCES. (1199) George Nothaas, Cleveland. Ohio, turn permitting the plane to decrease its writes :- landing speed.He asks our opinion. I have an invention which relates to A.-Many patents have been taken out on RANDOLPH & CO. AutomaticRailwaySafetyGatesthat various types of airplane wings which arc PAThNT ATTORNEYS would prevent all accidents on highwaystelescopic, or change contour so as to in- and railroad crossings.It works by elec- crease the speed when flying and decrease Dept. 172, Washington, D. C. tric current so that on approach of thethe necessary landing speed.We do not train,the gate would beautomatically believe that your suggestion is in any de- closed and stop the traffic, and whenthe gree superior to those that have already Name train passes, the gates would be open again. been patented, nor do we hold that there Kindly give me your opinion. is an immediate future market possibility Street A.-\\'e cannot hazard an opinion upon for a product of this kind.Your chances a railway crossing gate, theconstruction of forsellingsuch aninventionare also which is not disclosed in your letter. slight. We consequently advise no further City Will your railway crossing gate effec- action. tively prevent traffic in both directions and yet permit any traffic caught hal;-waybe- tween the gates and on the railroad right- Auto Wheel Attachment of-way, to pass safely off the tracks? (1201) W. H. Vande Hei, Manitowoc, PATE N T INVENTIONS Is your safety gate so arranged that itWis., asks what we think of a wheel at- EDWARD GOTTLIEB cannot possibly injure the top of an auto- Attorney in Patent Causes 5 Beekman Street mobile, a wagon, or come down on the head New York of a pedestrian? Inventions Developed-Representative for Isthis safety gate so arranged, that Blair Tool and Machine Corp. should traffic accidentally stop midway between the railway crossing, the engineerof the locomotive will be given a signal, so as Patents Trade -Mark, to notify him of danger ahead?If the EDWARDC.SASNETT gate comes up front the bottom of theroad, Registered Patent Attorney will it permit an automobile with its front (Ex -Principal Examiner U.S. Patent Office) wheels across the gate, to safely pass to the other side of the railway right-of-way? 540 McGill Bldg. Washington, D. C. Will your safety gate operate in all kinds Service of weather conditions-rain, snow,sleet and ice? Can your safety gate be erected so thatitwill not necessitate an additional tachmentforautomobilestopermit of .NEW YEAR -NEW IDEA space for railway right-of-way?Is your traveling through drifted roads.The na- PATENTYOUR IDEAS safety gate relatively inexpensive to install ture of this construction is further seenin Call or send me a sketch of the diagram. Phone LONgacre 3085 and is it practically fool -proof and will it your invention. remaiiinorderforalmostindefinite A.-Many devices hate found their way FREEVonggstInerdr:iiii:eg Blank lengths of time?If you can answer all ofupon the American market which tend to

I -. S. and Foreign Patents secure(' by Rea.PatentEn Attorne3 these questions affirmatively, then perhaps prevent an automobile wheel from slipping gine° Many 1Z.H.POLACHEKconsult. it might be a good idea to apply for a in traveling through drifted roads. INB 1234 Broadway,New York MB patent on the same. We must havefurther of these devices give considerable traction. details before our answer can be more Most of them fit on the automobile wheel specific. 'by simply snapping them around the rim.. They take 1/10 to 1/5(1 of the time to at- PATENTS Telescopic Airplane Wings tachonewouldneedforyour device \\ RITI: FOR FRFE INSTRUCTIONS and we consider that they are even stronger Send drawing or model for examination. (1200) M. S. Chapman, Johnstown, Pa.,than your system. which, because of the CARL MILLER, Patent Attorney Former member Examining Corps, U. S. has designed an airplane with telescopic nature of its construction. would not give Patent Office a reasonable bearing and traction service. 261 McGill Building, Washington, D. C. Any lugs extending from the wheel and as insufficiently braced as those lugs arc in the cuurtic tor awn of anibl- device you have designed, would get out of tumandlimited fined. order very quickly. ElectricalOver 5000 men trained. Condensed course in Theoretical and Practical Elee- Further, the mud guards so cover the includinit trical the close- tires that a decided change in shape is re- Engineeringly related Drawing. FRONT VIEW OPEN quiredtopermitthe movement ofthe subjectsof51.theroatiesan.ISleet mica! Students construct motors.installwiring.test elec- arms. trical machinery. Course designedto be completed fn onerollrge yen, In view of the fact that we consider your BLISS system mechanically weak, and that we ELECTRICAL SCHOOL consideritverydifficulttoattach, we Prkpare for your profession in the most interesting city in the orld. certainly would not suggest that you apply cn request. Iril Tekoma Ave.. Washingten. D.C. FRONT VIEW CLOSED for a patent on this idea. January, 1930 SeletiCe arid 1 'IZ'enii011 839

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

101 Protect Your Ideas Take the First Step Today-Action Counts If you have a useful, practical, novel idea for any new article or for an Inventors 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 (even though the inventors may live in different sections of the country b4fit-tizeae, and be entirely unknown to one another).In such a case, the burden of proof rests 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 and trademark cases.Our officesare 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 trade. mark owners located in every state in the Union. Strict Secrecy Preserved-Write Me in Confidence Allcommunications,sketches. drawings.etc..are' heldinstrictestconfi- denceinstrong.steel,fireprooffiles,which areaccessible onlytoauthor- ized members of my staff.Feel free to write me fully and frankly.It is probable thatI 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 itIwill send you my "Record of Invention" form, onwhichyou can sketch your idea and CLARENCE A. O'BRIEN establish its date before a witness.Such evidence may later prove valu- Registered Patent Attorney able to you.Simply mail the coupon and Iwill send you the booklet, and and Attorney -at -Law the "Record of Invention" form, together with detailed informationon how to proceed and the costs involved.Do this NOW.No need to lose a minute's time. 53-ZSecurity Sayings & Commercial Bank Bldg. The coupon will bring you complete information entirely WASHINGTON, D. C. without charge or obligation. -or- Suite 1106, Woolworth Bldg. NEW YORK (:ITY Clarence A. O'Brien Please sendme your free book, "How to Obtain a Patent." at.d your "Record of Invention" form Registered Patent Attorney without any cost or obligation on my part. & Attorney -at -Law Member of Bar of : Supreme Court of the United States; Name Court of Appeals. District of Columbia: Supreme Court. District of Columbia; United States Court of Claims. Address PRACTICE CONFINED EXCLUSIVELY TO PATENTS, TRADEMARKS AND COPYRIGHTS (Important! Write plainly and address office nearest you) January, 1930 840 Science and Invention What I Found on Board the R-ioi By Augustus Post For This Invention (Continued front page 781) v hat Eastman Kodak paid for theAtoraphleu g Wes. Thousands of other Inventions are needed and offer The galley(kitchen)fittings are even opportunitiesforearningi lighter; cookers, stoves, pipes and a forty fortunes. If you are of an inventive gallon hot water tank are all of aluminum. turn ofmind,tiltnot concentrate on things that ate really NEEDED? GetRaymond Yates's Passengers come on board by way of new book. the mooring -masthead at a height of 2011 1,000 NeededInventionsfeet, to which they ascend by a lift or costs only $1.50 and may start youthinking along the elevator inside the mast to a platform or right lines.bull get now here Just fussing around.Con- centrate on what the industries need,and on what the gallery at the top; they then enter the air- Yates'sbooktellsyou what these public wants.Mr. :lust write postal. Pay ship by means of a gangway let down things are. send no money. Your mall manf1.50 plus postage when book arrives. from the bow of the vessel in the same money bark If you want it.This offer limited. Write You then now and get on the right track.(Outside U. S., $1.70 way that you board a ship. Address pass down by an enclosed corridor lighted ',ash with order.) 70%Whisrier oktg. N.Y.by electricity to the passenger coach. This Bureau of Inventive Science structure is slung inside of the hull and who derive larg-is surrounded entirely by a double wall, est profits knowthrough which air is circulated to obviate and heed certain inflammable gas or INVENTORSsimple but vitalthe danger ofally facts before applying for patents. Our book, Patent -vapor penetrating to the living quarters. Sense,givesthese fuels; sent free.Write Windows in the side of the airship provide light and an opportunity to look out LACEY & LACEY at the view below; promenade decks, spa- 644 F STREET WASHINGTON, D. C. Established 1869 cious enough for a tea or a dance, are alsoprovided. Beyondthepassenger coach the corridor narrows and is used by the crew and forstoragepurposes, fuel tanks and cargo.Ballast tanks are INVENTORS placed on each side of the ship so that One of thepassenger staterooms on the Mayto nowobtain arrange PATENTS bytransferringthecontentsfrom one R-101. and pay for them on the basisof side to the other the ship can be trimmed. The five power eggs (named so from DEFERRED PAYMENTS their shape) look small against the huge teen times more expensive, butisnon- INVENTORS SERVICE BUREAU bulk of the ship, and the only other pro- inflammable and practically eliminates the Dept. C. Union frost Bldg.. Washinonn, D. C. jection is the control car as the passenger fire risk.The gas is contained in gold - heatersskincellsenclosedinaspecial cabin is entirely within the hull. form of netting within the metal frame- One of the most notable features is the work. Fiftyparachuteswerecarried. perfectsmoothness ofthemiterskin, Each rigger carries a knife in the ordi- which is obtained by a very clever stretch- nary course of his duties.These knives, ing device, light longitudinal girders that should an emergency arise, are to he used can he screwed out to give the required for the purpose of slitting the fabric to INVENT() tension. We hays beeninbindness 30 years. Iiyour The openings around the nose and at in- permit passengers or crew to jump. inventionorpatent has merit, send details or Commander 1..V. Richmond is to be model, or write for information.Complete facili- tervals in the outer covering insure a cur- heartily congratulated upon bringing to a ties.References.Adam Fisher Mfg. Co., 205-D rent of fresh air throughout, and ventilate Enright, St. Louis, Mo. successfullaunching the world'slargest the hull thoroughly. airship to be flown up to this writing ; one In the stern are the fins and rudders which cost over two and a half million that serve the same purpose as the same dollars to build.It was flown on October elements on a fuselage, insuring axial di- 14th, 1929, after being brought out of her tivENTORS' ODES rection in flight.The outside covering is hangar two days before and moored to clsanical Gabor linen balloon cloth treated with airplane themast. A notable company was on pecialists Eorovert. n dope and red oxide of lead to cut down Machine board for thefirstflight.including Sir Complete Service to the effect of the actinic rays of the sun. John Higgins. Air Marshal; Major G. 11. the man will, an idea .441 Designed,Budt The silver color conies from a coating of Circular -References - Guarantee - Free reflect the- light and Scott in command and Flight Lieutenant aluminum paint to Irwin.I had the pleasure of meeting Ma- BERNARD &HELLER ^-'31 East 17th St..N.Y.C. jor Scott when he piloted the first British dirigible to visit our shores. the R-34, ill 1019. returning- safely to Pulliamin75 hours, after circling Times Square ina Book on Law Free blaze of searchlightswhichflashed on her W nit, today for this new book .it tt Ils youhow NEW V 5 NAVY DIRIGI5LE5 Zi15,1ADM-5A-ENGTH 765T DIA LIZ 5 FE alaw training will shorten your road to suc- silvery sides as she derarted at midnight. cess. It also carries a vital and inspiring message to every ambitious man. Find out about the opportunities tlist await Ne law trained roan. Find out how you can learn law right in your can Novel 3lecbanical Features home. No obligations .The boat Is absoluteli Eons. low tuition Write Today-,^71,7h."° GRAF ZEPPELIN - LENGTH 776 F T-DIA. 96 FT. IN the construction of the R-101, every American Correspondence School of Law precautionhasbeentakentoguard 3601 Michnisn Are. Dept. 1421.Chicago. Ilk pgainst the possibility of fire, and for the first time gasoline engines have been su- perseded by engines burning heavyfuel FR EE CATALOG EngiG.BLE RIOT -LENGTH 724 FT. -61,5.131.6M oilwith aflashpointof 210 degrees Fahrenheit.To carry the 29 tons of fuel, Ft/CLASSPIN5I0t9". 38 main tanks are attached to the frame- SONIIIIINGDIffE/iENZ' PIN MPLETE WI HSEPARATE DATEWART:0E101APIC O 2 CMOs 4,0 work of the ship (inside the envelope) 28 Mt l STERLING SILVER $135 lien 5(20 V SNAPS ANGELES --LENGTH 650 ET -NA GO T .2 SILVER PLATE .75 MOM).65 of which hold 224 gallons and 10 112 gal- Comparative size of the world's greatest lonsapiece. Inadditionthereare 11 ers/rn.. METAL ARTS CO.,INC.950 Portland Ave.Rattesterl/i dirigibles. compensating tanks which arc tilled when the full load of passengersis not being heat.As these ships were built for the carried.Several of the main tanks have Egyptian and Indian Service, the question emergency gear for the quick releaseof of temperature in hot countries is a se- fuel, if required.The bottom of the tank rious one. and not only affects the lifting may be cut away by a mechanical device. power of the gas, but makes itdifficult ina manner somewhatsimilartothe Begin Today-Write for Mr FREE BOOK. I to make landings without loss of gas by method employed in opening some types Matte agood penntan_of_you at lionieNt=ni.a= For heating and venti- tune. Vi rite for tn_yFM. BOOK, valving. of cigarette tins. comeaGood rennian."It toutaine New iniena and tell. how ethers louvered peninanhip by Ilia Both thesedirigibles,the R-101 and lating the passenger cabins, air is drawn Hveteni. Your same willbe elegantly torn onn a card if yon endow stamp to pay poet. R-100, use hydrogen because itis difficult in by an electric fan and passing through Me. N rite today for bok. (Continued on page 849) F. W. 1 ambito. Ind f ofd..Renew. City. )4e. to secure helium gas, which is about six - January,1930 Science tiAd Invention 841 What Famous Men Predict for Sciencein 193o Walter P. Chrysler TC ROAPDYEARTHR TK (Continued from page779) !ration, by the use of stiffer chassis frames PATENTS and above all by the unit design of body and chassis, which permits the two units to be joined as one unified assembly with FOR THE PRODUCTION OUROFFER:-OF YOUR no points of xveakness.The automobile of INVENTION the future will be thought of as one balanced assembly, rather than as a group of YOUR FIRST STEP-Theinventor assembliesjoined together. The same shouldwriteforourblank qualities that produce longer life alsopro- form, duce quietness.In addition the use of live "RECORD OF INVENTION." rubber where it logically belongs, for the Before disclosing ourinvention,a purpose of insulating shocks and vibration, sketch and description should be will increase and greatly contribute toward made on our "Record of Invention life and silence.Adequate provision for chassis lubrication is also a factor that is Blank",signed,witnessed,thenre- securing greater recognition than ever be- turned to us and we will place it in fore.From the performance standpoint, our fir,proof secret files.We will also everything that the motorist desires will be give our opinionas to whether the provided.Better acceleration, better brak- r, ing, smoother, easier operation with facili- inventioncomeswithinthePatent ties for comfort and convenience will be :34 Office definitionora patentablein- featured in the car for 1930. % ention. This "Record of Invention" will serve as "proof of conception" Harvey Wiley Corbett VICTOR BUILDING untilthe case canbefiledinthe Our New Building Nearly Opposite U. S. Patent Office.There is no charge (Continued from page779) PotentOfficeSpeciallyErected by be built not with such intensive use of hand Us for Our Own Use or obligation for this service. labor as at present but n ith a fastening together of parts previously manufactured Write for Our Five Books Mailed Freeto Inventors in the factory, assembling so to speak the various elements of the building in much Our Illustrated Guide Book the same manner as automobiles arcassem- HOW TO OBTAIN A PATENT bled. The heavy masonry walls, whichare now hung on the steelframe, which of Contains toll in,truclo.P, S. Our Methods, necessity carries the load, will be replaced Terms, and 100 Nkehanical Movements illustrated anddescribed. with hollow construction-using muchmore glass and metal and less handmade masonry. OUR TRADE -MARK BOOK I regard these points as the outstanding Shows value and necessity of Informa- tion regarding TRADE -MARKS AND UNFAIR features of progress in the next fewyears. TION IN T RA DE COMPETI- William l)uhilier OUR FOREIGN BOOK We have Direct cuticlesinForeign .notrieq, and secure (Continuedfrom page779) Foreign Patctit- tubes will be the average employed in sets. -h..rtest time and at 1,,v e-! cost. I do not believe remote control willap- peal to the public. as it PROGRESS OF INVENTION is an unnecessary Description of World's Most Pressint.; and costlycomplication. The trendis l'r-Yems by Leading toward simplicit:.. Scientists and IN V EN TORS. Improvements will probably be made in the electric phonograph and radio setcom- DELAYS ARE DANGEROUS IN bination.Instead of using only the audio PATENT MATTERS amplifying stages in connection with phono- TO AVOID DELAY: YOU SHOULD HAVEYOUR graph pick-ups, as at present, while the CASE MADE SPECIAL IN OUR OFFICEto save corre- radio frequency stages are idle, the phono- spondence. secure protection and early filing date inPatent graph pick-ups will be simplified and so Office.You should send us a model, sketch or photographwith a description of your invetnion together with $25.00 on account. arranged as to affect the first radio ampli- We will make an ex:Anination of the U. S. Patent Office fyingstageandthus utilizeallthe records and ifitis Patentable ace will prepare the oilici:11 drawingsim- amplifying tubes in a set.This method mediately and forward thetn for approeal.I i the invention is not will enable improved music reproduction,as patentable we will return the fee less thee -of the examination. simple phonograph pick-ups generating in the order of .01 volt instead of one volt,as PAYMENT OF FEES IN INSTALLMENTS isused atpresent,willresult in more It not necessary that the total cost of a 1,0i:1J he paid illone effective reproduction by the loud speaker. payment. We permit our clients to pay for their applications Band filters will probably be used in the in three installments as the preparation c.f the applicationpro- tuning stages, which will improve repro- gresses in our t ffice. duction, especially of distant stations, for at 51,1. comut-Nic vrioNs. AND DST ',THU 11.1sECItET 511t ()SI liil NT' . present when a stationis tuned in, high 1\111:11 Ill 1I tin111:1\1.1- .111ENT7,1 ITN1.1:i 0,1.4 I'11-1). _ g:iiikation !Laslurcii established for:to notes are often eliminated on account of the and uilcra l'o is,11.11 Service by experienced Patent Lawyers and Draftsmen.Ave ;:hat! sharp tuning.By keeping the same sharp e,,nsuit. us or to ;11..sver our n'g,I1,1 T, r I tuning but widening the band of tuning, the without chart:,. high notes will come through with thesame intensity as the low notes, and reproduc- Highest References-Prompt Service-Reasonable Terms tions will become much more natural. WRITE TODAY '"" r- "" Enoughconstructiveinventions have FREE ' VICTOR J. EVANS & CO. been suggested to predict that fading ef- Registered Patent Attorneys: Established 1898 COUPON fects will be reduced. MAIN OFFICES: 715 Ninth St., Washington, D. C. One of the most important factors in the BRANCH OFFICES:1007 Woolworth Bldg.. New York City; 1640-42 Conway Bldg., radio industry will probably be straight- Chicago, Ill.; 514 Empire Bldg., Pittsburgh, Pa.: 828 Fidelity Phila. Trust Bldg.,Phila- ened out during1930, andthatisthe delphia, Pa.; 1010 Hobart Bldg., San Francisco, Calif. unsatisfactory patent situation. Either a Gentlemen:Please send me FREE OF CHARGE your books as described above. holding company will be formed by the manufacturersassociation to provide for Name the purchase of all patents into one group, Add and licensing all reliable manufacturers:or MMII =IN NMI rEi .M ON= 842 Science and Invention January, 1930 else most of the large companies holding valuablepatentswillamalgamatetheir Save patents, protecting the licensees from future $2000 litigation among themselves and by out- with this siders and tending to stabilize the industry. OFFER. Unless such a course is followed, the radio Send no companies are not assured that some patent mown may not prevent their doing business and will therefore work entirely till a year-to- year basis. Augustus Post (Continued from page 779) Get Stronggreater respect but a much wider use of the lighter -than -air craft. The already projected lines across the These ImprovedAtlantic bytheZeppelin Company and Muscle Buildersacross the Pacific by the Goodyear Com- pany, and the line from England to India by the English government, will be actually llfor i59-° in operation before we realize it. Races between dirigibles, both large and Why pay an extravagant price for strength-get all equipmentsmall, may furnish a new sky thrill, and you require and excellent courseserve to bring development much faster. ofinstructions for only $5.00. wrn. you learn to play, you have no idea of the rich Develop muscles of a super -man. The principle of compression ignition or Get strong and amaze friends. We jay, the vibrant fun, the big money that lie in the shot'how to easily master featsthe Diesel engine, will be used more and creation of music. And until you actually try out the which now scent difficult-if you more as the technical and mechanical prob- Deagan Xylorimba in your own home, you have no 'mat physicalculture for your health'. idea how easy this fascinating instrument is to play! sake,this equipmentisjuet what cots lems in its adoption to aircraft are solved, n eed. Save atleasthalf. We furnish Just think! No tiresome practice. No finger or lip ten cable chest meander adjustable to such as perfect fuel control, reduction of reeirimnintapto 200 lbe.Made of new. exercises. No teacher. On the first day you play sim- live. este.strength.springyrubberto long wear and rye ister.. you weight and the construction of the two- ple melodies. Soon you thrill friends and family with need forrealmuriele development. snappy fox trots, dreamy waltzes. Before you realize I, get of patented hand grips for cycle Diesel.There is no doubt that. as developingpar powerful grip and ferments. it, you are ready to appear in public. Xylonmbists are We in. lode wil mereising part which the aircraft industry has had much helpalways in demand. The pep of any party, the spiceof prrmde .ell to develop ,our back. arms .l loge-ei real nowt. necemity. from the automobile industry inits early any band or orchestra. 1.5 to $25 for a night of ' play! .cm men and athlete.,too.first age Is their legs. Develop log musele with foot stages, the rapid advance of aircraft engi-BIG BOOK FREE-Deagan Xylorimbas are sold ramp which we furnish.This willgive on a 5 -day FREE TRIAL basis. Models to suit every .IIwed and enduranre-hut that Writneering and new structural and motive moo gm.Inaddition we include a pocketbook. Surprisingly easy terms. You owe it to e peelallywritten row. contain. power development will be of inestimableyourself to write today for the Picture. and diagram. showing how to BIG FREE BOOK. No dirt vitro anypartofyou, body, in you value to motor -car builders, and a two-cycle cost or obligation. Simply fill in and mail the coupon. quickly getonwith them merriest and gaingreatest advantage from their ow. Diesel engineillmass production should Aft nowl quickly give a superior power plant. J. C. Deegan, lee., Dept. 1561,1710 Derteas Ave., Chicago SEND NO MONEY Please send me full detail, of the Five -Day Trial offer and Allitemspicturedoreincluded is Platformsoncitycenters,"floating easy payment plan of the Deegan Xylorim. thisepeeistoffer. bran name sod address to coupon and rush to us. We *end your ten cable chest de- islands," in the ocean, like the Armstrong voper. well parts, pair of hand seadrome raft, new and better instruments Name gps. footstrap andthe mom* 1,0 return mail.Pay postman for navigation and control in fog, partial $.5 00, plum portage onarrival. (IfYOU mod checket roomy order Marls mice. we pay pmeog..) automatic pilots and altimeters to tell not wog only how far you are above the surface All ertmarler product. ifgoer. of the ground; but the "Sonic" type mayLEARN TELEGRAPHY I.ction or mover bask. also be used to indicate if there is a moun- Ileanexpert Morse WITH _-:k1 `1/ or Continental rale tain ahead, and give ample warning ifitoperator!BID PA - TELEPLEX ( rirearler Apper.itt_e Co., is Fog -TRAVEL - FUN - Dept. 401. 44 Parker Ave., Maplewood, N. J. obscured by fog or darkness. ADVENTURE. After a few short penetrating lights or "infra" signals fromweeks of practical study with Tele- I accept your offer.Send me everything described pies you will be an expert operator. in your ailsr ntertiten ts:lai); oretna i ltclll flay beacons, radio direction beams for the pilot Thisamazinginstrument teaches you right In your own home.Works plus00 is tinder- to follow, rapid extension of meteorological WWI ifI ant not entirely aatielied after examination. likea phonograph. No knowledge ...n rat lint the goods and you will refund my money. information to include the ocean as wellneeded-beginnerslearn at once! NOT A SCHOOL. Free 10 days' as all parts of the earth.No spot on thetrial.Write till FREE booklet N-11. earth's surface will he unseen by the eyesTELEPLEX CO.. 72CortlandtStreet, NewYorkCity of man, the Pacific will he crossed without stop, the world circumnavigated by refueled

flight, an altitude of 50,000 feetwill be jj11.4.1111111 Cit Scats. reached by the assistance of rocket propul- - .vote-Ne C.O.D.Mk',Is Farces. .. et Canada. sion andNyeshall soon see further develop- ' ,,,,High School ment of the reaction motor, with more com- ,, -11 plete control and use of liquid gases for A VOA.1/4oweeI "'...T' Course in propulsion. 2 Years iThis simplified, complete HighSchool Prof. R. H. Goddard Course-speciallypreparedfor home study by leading professors-meets all require- Learnatlikome l y (continuedfrom page 779) ments for entrance to college, business, and Be a taxidermist. Learn leading professions. Mailto mount BIRDS. ANI- rocket plane travel, have already been madc MALS, GAME HEADS, FISH. under my direction in Auburn, Ntassach 20 OtherOver 200 noted Engineers, Bus - Wonderful fascinating new art.All se- setts, but these rockets are at present being CoursesInreesapprmanesd Elaufaitnwiruhcetlffd. crets revealed. Easily, quickly learnedby which you neer4 for success. No matter what men, women and boys.Decorate home developed formeteorologicalpurposes and den with nature's finest art. SPORTS- your inclinations may be, you can't hope MEN save your trophies. BIG PROFIT S only.America is not yet fully alive to the to emceed without specialized tonality,.Let for spore time. Sell your mounted speci- possibilities of the rocket and the uses to sn glee you Ow practical training yearned. mens and mount for others.Have a American School business of your own. Big demand. high which it can he put. greens Awe. A 55th Street pekes.Learn from old reliable school, Clopt.H-153Chicago yearn' experience. Money Back When You Finish If Not Satisfied "Casey" Jones w to Ezikumtixylowinttount American School, D ept.14-153 Drexel Ave.and 50th St,Chicago FREE,with dozens of photos of mounted specimens. Yours for the asking (Continued from page 779) Send me full information on the subject chclued and -FREE- Write Today. Taxidermy is a how you will help me win ucc in that firm. NECESSITY for sportsmen and nature lovers mean lower rates,itis believed that ton - Architect Electrical Engineer -INVESTIGATE. Get this wonderful rage of mail will increase constantly, which Building Contractor G I Education FREE BOOK NOW - no obligations. Write! Automobile Engineer tewyer Don't delay. Send CouponToday-NOW I will lead to the development of planes of Civil Engineer Mach. Shop Practic N. W. School of T much larger carrying capacity and greater Structural Engineer MchanicalEngineor 3791 Elwood Bldg.. speed. Business PA Siloam Engineer SOmahaend um your free Illustrated Nob. book While the performance of mail lines Sanitary ilk Heating "If ow toMootnt Game. A loo tell ow C. P. A. A Auditor bow I may learn this faecloating art has been extraordinary, they have been held Bookkoper Surveyor & Mapping eoolY and quickly by wait. Sic obli. Nigh Mee! Graduat stioo. up somewhat by fog.The landing experi- --Draftsman & Designer ments conducted byLt.Doolittlehave Name Marna Wuirked out very satisfactorily and possild A',Oren in 1930 developments will be continuedtit Address January, 1930 Scienoe and Invention such an extent as to make flying in fog possible, and ifthis is accomplished, airplanes will be able to fly tinder any weather rtinditions. Many efficient and well -operated passenger lines have been established in 1929, and P)30 will show increased patronage of these lines on the part of the public as a neces- Go After the Big -Pay sary adjunct in conducting modern business. Job! Several large passenger transports with two, three and four motors have been developed in1929, and the introduction to DoN'T be satisfied to worry along these on the passenger lines will increase in little jobs with little pay.Ifa,- the efficiency of the lines and by doing this ter the liner points of electrical prac,. %\ ill encourage the increased use of them. and bring the big -pay job within yui.: By 1930 many well reach.The man who knows electricity conductedflying in all its many phases-the man who has schools, under the approval required by the completely mastered the subject from Department of Commerce, will be in opera- A to Z-can pick his own job and name tion, with new equipment, well organized his own salary. fields and competent personnel.Thisis Learn the way to big- bound to increase the interest, particularly ger pay.Become an electrical expert! zunong the younger generation, in learning Croft will show you how. Through his to fly.The establishment of numerous air- famous hooks he will teach you elec- ports and well-equipped service tricity as experts know it and put you in stations line for an expert's pay!Fifty-nine throughout the country generally, is bound "KuZZ' electricity as experts knox it and thousand men are using these books to to encourage private flying. et an expert's pay' Generally speaking, the outlook for 1930 step ahead-WHY NOT YOU? in aviation is excellent, and with the developments mentioned above we are looking Croft Library of PracticalElectricity forward to a most prosperous year. 7 volumes -3000 pages -2100 illustrations, flexible binding No method of teaching electricity offers a quicker,surer way to success than tlo.. Turbo -ElectricDriveforPas- Croft books. senger Liners of Major Im- Starting right in with the ABC's of modern electricity, Crofttakes you through his books in easy steps.He gives you the boiled -down records ofevery -day electrical portance, says practice in plain words, figures and illustrations.Nothing is left to the Frank V. Smith imagination-there is no guesswork. Croft has been through themill.His knowledge of Federal and Marine Dept., General Electric Co. gained by actual shirt -sleeve contact with electrical problems.electricity has been what is needed to get ahead. He knows just URBINE electric drive for ships is an lie has poured out all his knowledge- .n 1 experience-in languagelanguage that anyone can grasp.Vet the text is so scien+ American developmentindependently correct that thousands of the highest paid electrical emgicec:.s arc using planned. It has in a few years built as a reference set. and laid the foundation stones of what The famous set is. beyond the shadow of a doubt, the last word inpractical electricaleducation. No one who wishes toget aliwheve in has become the most distinctly progressive can afford -to be without it. the electricalfield Thousands of Facts at Your Finger Tips The Croft Library contains three thousand pages, with twenty-on, hundred of the clearest illustrations ever put into book farm.Each of the seven flexible pocket-size volumes so that everything you need to know is right at your fingertips. arc indexed Croft tells you the things you need to know about motors.generators. armatures, commit. tators,transformers,circuits,switchboards.distributionsystems- imtallaiion.operationand repair of electrical machinery-wiring for light and power- wi,i,_!sitinisbe.lbuildings --11110,-- writer's and municipal reuttireincitts-howI.. do a complete f, ,,in ,-,.,ting toc. pletion-illuminationin it its every phase-the lat- estand most improved ...a41111.1" - methods of lighting, signal '71==le wiring, etc.

The Standard in UMW UNARY LIBRARY LIBRARY LIBRARY Ubilar Practical Electrical V V V V hvocit Puma NM MX71C4 flume A00101. Nam. Training am=ElKIETY &muff hmly lummyFORM' EMT! Everywhere theCroft Library is acknowledged asthestandard - the leader-in practical electrical training.It is the dailyguide of 59,000 highly paid electrical i'sactica workers and engineers. ?itscnou.7 PitAcncx CENTRAL falInCAL There is nothing like it. viaEmArics LEVER EIECIRK111 STATioNS WINDY Itis the most complete. MR Ti FMK E 101telf the best illustrated, the PALMER csOrr caorr csorr Caorr ar6sr most carefully compiled. themosteasilyunder- stood library of electricity / in print today.No mat- / step in marine engineering in the past two ter how muchor how j McGraw-Hill decades. little you know of elec- / Book Co., Inc., The turbine electric driven liner typifies tricity eon will find the 370 Seventh Ave., CroftLibraryasound. / New York, N. Y. thatmodernityandup-to-datenessof helpful cubitto coiate;- C. -nth -men: which the American traveler feels he is an acestupli.hinent. Send methe NEW integral part.The brilliant performance. NEWLY / CROFT LIBRARY 4c CERA. / of PRACTICAL ELEC./ the uniform efficiency, the endurance, the FREE HILL TR I ( 'ITY (shipping charges incomparablynoiselessandvibrationless Examination REVISED / prepaid), for 10 days' free ex- opt -ration, represent a vision of complete / am citation. Ifsatisfactory, 1 :old striking usefulness. No Money Down - / will send $1.50 in ten days and There is a new 10 Months to Pay! UP TOTHE / VA per month until$19.50 has magic, something inspiring in the unseen been paid. Ifnot wanted,Iwill power. which drives thepropellers. and So that you may to -t our ,trd, MINUTE return them.c To insure prompt ship- which can be controlled so easily by means Mel we oiler to ',lid the com- /mein, write plainly and fillinalllines.) of a few small levers. plete library of 7 volume, to put for In days' free examination. We Nance Every new development is reflected by - take all the risk-pay all the charge,.You assume. no the manner in which it is received by the obligation of any kind-you pay nothing unless you decide to keep the books. in which event you pay $1.53 in Ironic Address public.The all -electric ship has been pub- ten days and then $2.00 a month for nine months. licly acclaimed becauseithas never re- Send the coupon now and see the hooks for yourself. l'ity and State linquished that deeper purpose of spread- It's a little thing to do but it may prove to be the best ing the finer things of life.The creation move ton ever made in your life. Employed by of a new standard of luxurious -travel com- Occupation 51.1-30 cif Science and Invention January, 1930

fort is a tangible expression of the newer Let Strongfort Restore engineering, and a priceless heritage to the younger generation. Our latest and most modern passenger YOUR SHAKY NERVES liners, which are of the all -electric type, pave the way to a new era in sea trans- If your nerves air .1;1ajatial. ; ityou are tearfulat everything portation.A majority of the new ships -afraid ofeverybody:ityou have gloomy forebodings: if that arc building are of the turbine -electric scar digestive apparatus is di, type, and other vessels proposed have writ- ..rdered:ityousuffer fromall artsofailments;it youare ten turbine -electric into their specifications. timidandnervousinsociety: The handwriting on the \Vali points to ityou haven't the manly tour- LEARN ..grto go atter what you want- theall -electricpassenger linerasbeing youarelackinginallthe manly attributes that win favor the liner of the future, because the people BY DOING ,nd success inlife,you areto once having tasted of thefruits of the Lvety phase of all he pitied-you areon theto- branches boggan,plungingswiftlyinto newer engineering will not turn backward. mentaland physicalchaos. Avoid Disaster ELECTRICITY Ifyou allowthis nervous eon. Some Scientific Radio Problems ditionto continue,itisgoing tolead you onto utter demor- Which Will Be Studied in 1930 alization and disaster!Itwill dragyoudownanddown-at By Dr. L. W. Austin Actual Practice firstmentally and thenphysi - ally andthen,worstof allfor Special Radio Transmission InAmerica's foremostanal Research, Bureau of Standards oldestinstitutionfortrade Here's a Helping Pr E mostpuzzlingofthepresent training Hand problemsinradio -telegraphyisthe ASpecial Course in Don't go en slipping further and determination of the cause of Mechanics andElectricity I letherintothe canyonofde - forAutomobiles, Aeroplanes 'pair.Don't suffer all kinds of the long delayed radio echoes dise,wet-rd dwells and become a wretched and Marine Engines takling.Don't think your case by Stormer and Hals in Norway, STRONGFORT is hopeless.Let Lionel Strong - arcsometimesreceivedonvery individual Instruction Builder of Men torttake holdof you. There Start Any Day isn't any doubt about the won &Hui transformationshehas wroughtin nervous ;Flute for FRFF 64 -page catalog areeks through STRONGFORTISM There Is nothingexperimental aboutSTRONG- THE NEW YORK FORTISM.Itis based on the fundamental factsof Nature and the functioning ofthe muscular system. ELECTRICAL SCHOOL Nothingisor ran be superior toNatureineradi- eatinpthefaults andfailures and disorders ofthe 29 West 17th Street ,New Yort0_ it human body.Strongfort gives Nature a chance!He wakes upyour lazy muscles-makes them dotheir work.This way lies health. strength. wealth. happiness. Come, man,wake uptoyourpossibilities! Send for My Great Book -Life's Energy Through Strongfortism"isa revela- tion of inside farts about the human body that makes itapriceless possessiontomen seekingtobanish Only 4 Motions used in playing this fascinating s itality-sappingailments andweaknessesunfitting hist! einant. Our native Hawaiian Instructors themforlife'sduties andresultinginconsequent tench you to master them quickly. Pictures mental depression. show how. Everything explained clearly. WRITE for your copy TODAY.Don't delay. Use Play in Half Hour Easy the coupon below. After you get the Even ifyou don't four e n y motions know one mute Clem :Alpell:yrtnri'n:resl Vir=1;,,sr.s. and TIONEL STONFORT little pructice. Nn clear pictures make ad PHYSICAL AND WEALTHSGPECIALISTelk previous musical larnquirk. FOR OVER 30 YEARS knowledge needed. Iii.yPay a, you play. Dept. 1 Newark, New Jersey GIVEN' when you enroll U.S. A. ''"-whensweettoned - -Send this Coupon ------HAWAII AN GUITAR, Carrying. Celts Lionel Strongfort Institute.Dept.I.Newark. N. J. WRITE AT ONCE fur aurae- and Playing vit=t t.te.t.e-end,ac 1..0' tive otIor and ea.y terms. A Inc of your book. "LIFE'S postcard will de. ACT I Value elate lite ENERGY THROUGH STRONGFORTISM"unitIn- No extra,. et i elk.. Included rnatiml about Nei you tar sstileli1 emir., lac. touniesiLZ: Er.r,:i.V.Ioliiindreirple,.: j.....ione,,(3,flunitiiinr;.,yokcii:oersie: I his die; not plait toe tinder any obligation Mai 110 tle-Inan Is 10 Call oil Me. FIRST HAWAIIAN CONSERVATORY of MUSIC. Ina. 9th Floor. Woolworth Bldg.. Dept. 240 New York. N. Y. Photo by Baehroeh Approved a a 1'0r...ode. e S. hoot I...drr the Loa. of the Iriiit Name State of Nero York-. Me... Nat.out Home .'rude a...M. waves from one to thirty seconds after :e. Occ..; the main signal has arrived.The question seems to be whether these echoes travel Ilome Aditiess with the velocity of light and are reflected In stock-immediateGEARS delivery back from clouds ofionsin space far smorket out beyond theorbitofthe moon, or tthrust bearings.flexiblecouplings. pulley..et.. A completelino Ls whether they are simply delayed in some canted innurI'M, ago oturk.fan way not yet clear in their passage through of qumo oilslier lalgin', of any t he earth's upper atmosphere un their way kind. Selol MI your blue -pi Dili and CHEMISTRY othe receiving station. forCatalogNo. 40 Chicago Stock Gear Works Complete, practical home-studyk Among the other questions which de- 769-713 W. Jackson Blvd.. Chicago, III. courses prepared by some of the mandfurtherstudy are: The general t,r,',/ best-known chemists inthis country, includingelectricalconditionsinthe upper atmo- t - - ALLEN ROGERS, B.S., sphere and the characteristics of the radio .i. M.S., Ph.D.-Ilead ofwaves which are reflected hack to earth; Department of In- , ,I,IstrialChemistry, whether the variable deviations in direc- .ittInstitute:L. tionfinding- are always (Inc to abnormal

I . TOLMAN, l'h.D., polarization in the down -coming wave, or Send roar name and address for free booklet giving interesting In- Vice-president, formation and vital recta about Advertising. Hurl out how we x7. pare IIUnited Chemical sometimes to a real change in the direc- goo at hem, in your spare time. for tbr_appirtunitice open in tine fascinating hostile.. Practical work. No text book.. Oldstab. \ and Organic Prod-tion from which the -wave reaches the di- Imbed imbue!. :40, ceingfol graduates everywhere. ,Twit tbe pku sou .._: -.6.,ticts co.; BRADLEY have always wanted. Write today. Nu obligation. ...-a----- 1, rectionfinder;the connection ofsolar ,/ STOUGHTON, B.S.- activi:y and magnetic storms with radio PACE-DAVIS SCHOOL OF ADVERTISING ..--411**" HeadoftheDe- Dept. 1421, 3001 Michigan Ave., partmentofMetallurgy.LehighUniversity,and reception; whether true static is entirely chino% U.S.A. OWEN L.SHINN, Ph.D.- ProfessorofApplied Chemistry, University of Pennsylvania. due to lightning discharges somewhere in Mail Coupon for Free Booklet the world, or to atmospheric discharges a.i. f -mother nature. WITH THE INTERNATIONAL SCHOOL OF CH EMISTR-177 Division of the international Correspofidenco Schools. j Box 6207-F. Scranton, Penna. Progress in Aviation ARKOGRAFProtect YORE I 1 i Willi/aft rc,t or obit :lion. please semi me full Tools F roily Thef t. .Ic-- I a..,.i i I,nl yourIii, hc-Audy course in By "Eddie" Rickenbacker I 7 Analytical Chemistry n Metallurgical Chemistry I America's Premier Ace 01 Chemical Engineering [7] Short Chemistry Course is CompleteOutfit a Industrial Chemistry j Pharmacy PkOGRESSin aviation during 1930 in 93.50 Prepaid Anywhere. I.., st wan . Write "" Name I my opinion will be in a steady advance Alongalllinesofaeronauticsboth ARNOCRAF PEN CO., A.Hrris I 1171. E.Stark St.. Portland. Or-...... 3 ; ; I iter - than - air and heavier -than - air, January, 1930 Science and Invention 84 rather thanin sensationalrevolutionary I , development. We have already proved that airplanes which would havebeenconsideredgi- gantic a few years ago are not only feasible but economic in operation and prob-

BIG 501.11TI.E. RICH AND POOR. CAN PROJECT THEIR 1ERS0NAIITIESOVER THE WIDE NETWORK or ITS WIIIES

"Eddie" Ricfrenbacker In the service of all thepeople ably the forerunners of much larger ships. In the same way lighter -than -air aviation ,Idvertisement of the has seen the girdling of the globe bya dirigible and the launching of a still larger dimerican Telephone and Telegraph Company ship in England while two dirigibles nearly twice the size of the Graf Zeppelinarc under construction at Akron, Ohio.These airplanes and dirigibles undoubtedly will THE Bell System is owned puttinginthousandsof be dwarfed by the ships yet to come but by 450,000 stockholders and this advance will not be made in ayear. miles of cable, thousands Ilook for the extension of air trans- operated by more than of sections of switchboard portation in 1930 comparable to itstre- mendous growth in the past two years. I 400,000 workers for the service ofand hundreds of thousands of look for construction of many more air- the people of the nation. ports.which arc essential to stable growth new telephones.Its expenditure of the industry. I lookfor increasing Itis a democratic instrumentfor plant and improvements care in training of personnel which will in eliminate casualties calved by pilots' mis- of a democracy. Big and little,service in 1929 will be more than takes.This isthe growth that aviation rich and poor, can project their needs and will have in 1930. 55o millions of dollars-half again But I do not overlook the possibility of personalities over the wide net-as much as it cost to build the a revolutionary step forward by some in- work of its wires. For friendship spired engineer or inventor.With avia- Panama Canal. tion still in its youth anything is possible. or business, pleasure or profit, the This program is part of the tele- telephone is indispensable toourphone ideal that anyone, anywhere, Astronomy in 1930 modern civilization. By Dr. Donald H. Menzel, Ph.D. shall be able to talk quickly andat Of the Lick Observatory, Mt. Hamilton, Calif. This year the Bell System isreasonable cost with anyone,any- TOattempt to recount all of the ad- erecting new telephone buildingswhere else. There is no standing vances of astronomy in so few words in more than200cities. is an impossibility. To confine my re- Itis still in the Bell System. marks to but several of the many achievements is hardly fair to the investigators J whose researches are of equal or possibly - greater merit. Ishall take a bird's -e. view of the battle -ground of science, Agents Wanted thattheindividuallandmarksfuse t Magnified 225 Diameters gether. The enemy is ignorance; the skit This is what the tip of a fly's leg is likewhen seenthroughthe Anti -Mist mish line the frontier of knowledge; Guarantees ClearVision the unknown lies just ahead. Ultralens You eakilyinchuia, i.. , . War sc..:Mq.7.. .'', :;'',:'nerriii Each passing year has seen greater co- Microscope 4 24;,,, -i.i:;;;;----!,..t,...,, Ile..of your own selling operation between astronomer and physi- Atlasta high TT'.'s'aratiiie.-'' Anti -Mist.Sella to aul. powered micro- f...... ,:tusp.oeltza;do,rteosr.,,.or:4I,I:. I cist-and now the respective sectors(if scopeIswithin there be two) arc so united that no division the means of all At railroad::andstreetear who wish to ::7-' , Darin,. Anti -Mist makes via can he distinguished.The scientists are study, observe 1,Ita4T- I ' 1:0111,, STEAM- I'll 00 I, and %TATE): - andexperiment I' RO, IF. Oneapplicationlasts 24 hours. Clear lighting each other's battles.That heavy withthe vast V1,101. guaranteed In all n cattier; money back guar- barrage is being set up by the relativists, world of minute antee ifItfails. objectsinvisible who arc more firmly entrenched than ever $50to are doing i. S5.00 for Complete Outfit Prepaidto the naked eye. $100 WEEKLY (;.etIiT.:"data.Anti- in their conviction that Einstein is right. Such funItis. Mht retails at:Ile for3', on.can -SI. 7,0for 3 0, as well as educa- inn. Send 35 NOW for ,ample on. can and fu;1 The fight has not been easy and there istionl No wehnleal training required.yet hundreds of part leulare. scientists and teachers are using this Instrument.Gives GASTON MFG. CO. no sign of cessation of fire. enormotia magnification and perfect definition.Send 85.00 for complete Dept. 863.A. 4216 Lincoln Ave.. Chicago.III. There is another scene of tremendous own.Send for descriptive literature. CanadianRepresentatives: bustle.The atomic theorists are wagingROAT & LOHMAN, Dept.203, Milton, Pennsylvania Matty & Co.. 613 Ponder St. W.. Vancouver. 8. C. 11) Science and Invention January, 1930

an attack, and new ground isfast being won ill fields both physical and astronom- LIFE -TIME DX AERIAL ical. Itissignificant that the greatest ELUTRICAL activityalways occursinthe neighbor- luvromaaanvG hood of the physicists.Judging from the BOOKS SENT FREE Guaranteed Double Volume and SharperTuninq New Edition Containing 100 Pages on Description of Lifetime DX Aerial A -C RADIO! No. 30-LENGTH 30 FEET: We're glad to send a set to your 8FLEXIBLE home to examine and use as your Assembled ready tostringup.Brings in MAROON own for 15 days-to show you VOLUMES that here is the most up-to-date volume of 150 -ft. aerial but retains the se- 4.100 inert.3200 and complete work on Electricity lectivity of a 30 -it. aerial.Rings are heavy illustrations, deluxe everpublished. Fold ntamped Writtenby gauge solid zinc.Duplicates in design and laden in each CROCKER of Columbia IL- non -corrosive materials the aerials used by hooks general index MILLIKAN of Calif. -Tech. in%ol.S.Covers -HARRISON of General Elec- most of largest Broadcasting Stations.De- subject in tric and 28 other noted Electrical sign permits using this powerful aerialin Everylectricity-Light, Power.Tranamismon, Engineers. Starts off with ele- 30 -ft. space (preferably outside).Sharpens Generators. Motors. mentary Electricity In simple. Switchboards Radio, non -technical language fur the tuning of any receiving set because of short Telephone Ifoune beginner and includes every length but has enormous pick-up because 150 Wiring Itailwaycetc. Engineering branch for use of ft. of No. 12 enamelled wire is used.Made eNperts on the Job. for owners of fine radio sets who want great volume on distance without destroying sharp Complete Electrical Reading Course tuning.(Also used by many owners of short- Electricity, the biggest Industry In the world, contitim, wave outfits.)"Makes a good radioset to grow the most rapidly. And it offers better Jobs. better." bigger salaries and a brighter future than any other field. Every dollar. erery hour forestedInlearning Elec- PRICE, SI0.00 tricity will come back to you a thousand -fold. Learn In spare time with these books at one -fifth the cost of trade courses. Outline for organized No. 60-LENGTH 60 FEET: study.quiz -questions and a year's free consulting member- Assembled-ready to string up."Big Boy" Look it up! ship In the American Techni- size.(Same description as above except that Thousands of these cal Society ftactuded without extra trioarewed am It if pal mall column Itome- 300 ft. of wire is used. making this the most Lads by men em - ,i, efficient and pit erful aerial possible to man- hloved in electrical. ufacture.) huildingconatruction nd allied lines. The AMERICAN TECHNICAL JIFFY INI)EXputs Brom n-113er. Studio, !Miter PRICE, $12.50 the answers to 20,000 SOCIETY mit...twosrichtat Dept. E-125 3uur Dr. Donald II. Menc,c1 Drexel Ave.& 58th St., Chicago Manufactured by progress of the past year,itseems safe THOROLA RADIO PRODUCTS, ito predict that the major activity, in 1930. Willbeconfinedtothosebranchesof 1014 So. MichiganAvenue Chicago,Illinois astrophysics most closely related to atoms. and that the close of the year will witness a marked advance in our knowledge of the spectra of sun, stars, and nebulae. tine Elna American Technical Society Gift Dept. (-125Drexel Ave. &58th St., Chicago What We May Expect in Radio Please send for 15 days' free trial 5 -volume set a Electrical for Engineering Just off the press subject to return if I wok to. as Visioned by John V. L. Hogan (I pay the few cents express charge. on receipt of books you payexposeif returned./IfI decide to keep them.Iwill IF present tendencies are a safe gInde, pY112.00 after 1 S days trial, then $3.00 a month until 834.50. - special advertising price, is wad. after which books become we may expectradiobroadcastre- Him my property. Year Consulting Membership to be iactuded ceivers of 1930 to be characterized by free. No more ragged.era,lad the more efficient use of fewer tubes, by Packagesofcigarette - Name of tobaccofilledpocket- I,. furthersimplifications operatingad- looking, clever.suns.. justme:lts and by even betterfidelity of likeitforissivenlei.,. Addrea, See atdealer: Ihr Pi iced at$1.:".o.52:11$1.11..5.1.80 and $35.00. Employedby If riindealt.,11,1'1 the E:tulor write to giving hi: Ming sad enrioing price. ployer'a Aridness TIELYONS MFG.COMPANY. Dept. N, MT. CARREL NEW NAVIN. CONN., 11. S..; No Wind Can -4I'LL PAY YOU glow 091i LI$20 A DAY To Show My Mystery Lighter to Men. What Makes it Light? All Guaranteed.Sample With Sales Plan Sic.Sample Gold or Silver Plated, $1.00. Agents writefor proposition. NEW METHOD MFG. CO. Desk S.I. 1 Bradford, Pa. Sport Plane Blueprints Learn Public Available at Nominal Cost Speaking At home-in spare ttme-20 minutes b (: Complete Set of Blueprints day. Overcome 'stag.-(right,"rain self- confidence. increase your salary. through ofLincolnSportPlane, ialsolity .wayothersby Ifective 'speech.Writs now for fres booklet, $6.75. How to Work Wonder, With Word.. attringraii,.rign.lostito.tet C47,4142.!1. 9 Gerber Monoplane-set of Blueprints, $1.00. 1.1,. of 33 rare 52.110, 20 cabinet and .20 Send Orders to Blueprint Dept. inlay$1.75,or)on. WOODchoice $1.00. SCIENCE AND INVENTION Sets labeled and postpaid. OF ALL KINDS Send lee Price list. 381Fourth Avenue CRAFTSMANWOOD SERVICE Audi I. r. New York City VV -715 E. 62nd St. CHICAGO JO/iii 1'.1.. Iloyan January, 1930 Science and Invention 847

reproduction thanisshown by today's average.Automatic and distant -controlled tuning and volume setting arrangements scent likely to be prominent. The preparatory work of 1929 should The NEW HT I Mastertone result in moderately extensive exchange of internationalprogrammesduring 1930. There have already been several notable LaboratoryMade Receiver. examples of such relay broadcasting, and the coming year islikely to bring forth many more of them. In radio communication. it is certain that both the radio telephone and radio telegraph will hatter down old barriers and provide a communication service betwet nations not now connected by radio.Eve' theold dream ofa nationalinter-cit service by radio seems about to come true, although perhaps in a somewhat limited f orm. As to electrical entertainment, aside from broadcasting, we may hope that intelligent application of radio principleswillfur- *Tht4,Sic ther improve the talking motion picture asithas the phonograph for home use. Perhaps we may even have television in I such simple and practical form that we can enjoy it in our own living rooms, but it has been "just around the corner" for Completely Built and. Assembled by so long, that thedoubling Thomasclan must be admitted to have some grounds for its skepticism. H -F -L Engineers,Shipped ready to Operate

A Vision of 1930 by President of Allmetal completely shieldedchassis: 7" x 21*x7 I;". Fits nearly all consoles. 11 tubes Radio -Victor Corp. of America operating at peak efficiency [5.224;3-227; 2-245; 1-280.) Single dial positiveone -spot tuning; Humless AC Operation; Uses 5 Screen -Grid tubes, 5 Tuned R. F. Circuits; NENV high standards of utility, quality HighPower Screen -Grid detector, with 175 volts impressed on plate; Automatic line and appearance have been set for the voltage control inbuilt holds voltageagainst fluctuating; 100 -Volt DC Dynamic field 1929-30 radioseason by an expe- supply incorporated; 3stage Phonographic amplifier; Finest quality precision made parts. riencedand discriminatingpublic. In previous seasons, public preferences have Amazing Power Highly Developed Circuit been clearly defined in one or more par- Startling realism! Unfailingaccuracy! Its Intermediate employs 4 screen -grid tube, ticular features of receiving set technique. great power and sweet tone awe and thrill, with 5tuned filter circuits, easilyadjustable Thus, in the early days a radio set was setting new standards of to peak of tuned frequency. Positive 10 achieved by H. F. L. engineers after two Kilocycle selectivity.Most highly engin- years oftireless research and tests under eered receiver ever built. all conditions. The New Audio System Keenest Sensitivity Uniform amplification over entire musical scale. Operates with dynamic, magnetic or Unlike any ever known! Gets distant horn speakers without a bit of hum. stations clearly, sharply, distinctly with only wire screen or metal plate aerial built in The H -F -L Power blaster cabinet. Not an 3rdinary power pack,butaspecially devel d unit of the Mastertone, built separately to simplify installation. Has oversized transformer, fullwave type 280 rectifier tube. Built by Hand-Yet Low inPrim - Quality-not quantity-theH-F-L Mastertone standard. One dem- onstration will convince you that its the master receiver of all times. Fully guaranteed. Write today for complete descriptionand price. HIGH FREQUENCY IABORATORIET 28 North Sheldon St.Dept 23Chicago, Ill.

J. L. Ray, President, Radio -Victor Corpora- new MONEY MAKING OPPORTUNITIES111/241 tion of 3 merica. Sellguaranteed Tailor - madeMake *12 a day and get new FordHotels Need Trained Executives- clothes. Lowest ',noes. Big profits. Yoursedan Free, taking orders for our line,Nationwide demand for trained men suit Free. Write for Freesamples. Jayall-wool union-made, made -to -measureand women: past experience unneces- judged by how many distantstationsit ReeeCo., Desk 6, 4048. Wells, Chicagosunset $23.50 up. Biggest commissionssary.We train you by mail and put could bring in. A Paying Position Open to Repr. ofpaid.Experience unnecessary. Fineyou In touch with big opportunities. Attention was next direct- character. Take crders Shoes -Hosieryoutfit of large real cloth samples, Free.Write at once for particulars. edto power supply, passing througha direct to wearer. Good Income. Perma-Spencer Mead Co., Harrison itTiiro09 Lewis Hotel Training Schools, nent. Book "Getting Ahead" Free. Tan-Sts.._Dept. N-972, Chicago. Room 13W -W637, Washington, B. C. period of evolution from dry battery, stor- ners Shoe Mfg. Co. 2141 C St. Boston.Agentsearn big moneytakingorders$95 a week, genial union made -to - beautiful Dress Goods, Silks, Wash age battery, and "eliminator" operation to Old Money Wanted-We Will PayFabrics. Hosiery, Fancy Cos. 1000measure, all -wool salts & o'coats at perfected socket power operation. $50.00 for 1913 Liberty bead nickelsamples furnished. National Importing$25 30. $35. Biggest commissions paid As the (Not Buffalo). $100.00 for dime 1894 S daily. Extra bonus. Write for details. permanency of radio became assured and Mint.Big cash premiums paid forCo.. Dept. Z-89, 573 BroadwaY, N.YNearly 200 pure -wool fabrics Free. thousands old coins and stamps. GetAgeats-11ffyGlass Clean siiitsPioneer Tailoring Co., Congress & increasing numbers of broadcastingsta- Posted. Send 4c for large coin folder.other new specialties offer you wonder-Throop. Dept. N-1272, Chicago. tions crowded the air, good selectivity be- It may mean large profits to you. Nu-ful chance to mae $15 profit a day.A Business of Your Own, Bankrupt mismatic Co., 11 pt.60, Ft.Worth. Tex.0ohlit big. Hurryt Albert MILL% 5014and Bargain Sales. Big Profits. We start came the prime requisite.As thefirst Monmouth, Cincinnati, 0. you. furnishing everything. Distribu- novelty of radio wore off and the public Make Big Money with our All -wool$S.S Every Time You Sell Mytors.Deot.279.429W.Superior.Chicago. Tailored -to -measureSuits.$23.50-Tailored -to -Order $35.00 valueall -We Start You Without Dollar. became more exacting, the old horn type $29.50.Commissions $4-$5. Outfitwool suit for $23.50. If you want to try,Soaps,Extracts,Perfumes.Toilet free? General Tailoring('o.,Dept.write? Everything furnished free. P. A.Goods. Experience unneceoary.Carna- of reproducer gave way to the cone speaker PC -1. 618 E. Jackson. Chicago. Bubb, 2256 S. LaSalle, Chicago. Bon Co., Dept. 670, St. Louis. Mo. 848 Science and Invention January, 1030

and the electro-dynamic speaker; the mul- ELECTRICAL tiple and involved controls of the early AND MECHANICAL radio set resolved into the simplified tuning and volume controls of today.From the ungainly and disorderly looking radio as- semblies of yesterday the radio receiver has emerged as a thing of beauty,sell -contained and enclosed in cabinets which grace the most pretentious as well as the more Be an electrical specialist Cain quick success'in !hi, most modest homes.Now, all the requirements fascinating and profitable held. Learn at National in the of sensitivity, selectivity, good tone quality, center of tremendous electrical projects costing more than simplicity of control and appearance which Ste(NAX,,IXXia.`0 - unlimited opportunities now. were the exception in previous years, are Practical, intensive training by National's job.rxperlenee method in 6 to 9 months. All technical essentials Melodist embodied in the present-day radio receiver. School endorsed by leaders ineirxtricalindustry. You learn Another outstanding feature of the cur- all heanchc, of electricity; radio. Million dollar instinitx,o isthe unusually good all modern equipment and training tacit rent radio season ities. Life scholarship. No age limit. tree values which obtain.At no time ill radio's employment 'mice. Over 17,000 SUCCes, short but spectacular history hasitbeen ful graduates. 23rd year. Big, illustrated possible to get so much for the radio dollar. 84page catalog seat FREE. Write today. No one, regardless of circumstances. need 14113:10NAL ELE CIMICAL SCHOOL now be withoutthe manifold pleasures which the ownership of a radio brings. Dept. 30.11 ! lo, 1, 4nk les.t 0111 Nor need anyone cling to the old and obsolete receiver which has outlived its highest efficiency through radio's experimental and formative days, for in this fast moving CAMERA MEN EARN 1316 MONEY art the 1929-30 radio differs as much from the radio of four, three, and even two years $60-$250 a W eek- ago as the 1930 automobile from theearly Fascinating Work "horseless carriage."Everyone can now .. - t ! fortraimil own a radio. which may rangein an almost camel - 1.11111,, 0111:I i4,11a!andindustrialfields. USE limitless variety of design from a modest One of these enjoyable, well -paying Scissors Nowfor but highly efficient table model to the most positions,withunlimitedtot urn, I P advanced product of radio and phonograph Can !re ours. this Amazing engineering and cabinet craftsmanship. Now You Can Quickly Qualify COUPON At Home 10 um' ciom,11 le AVIATION home -study

Courtesy Notice 4914 6/$1tell Inthearticle"RailwayCarsTake Wings," in our November issue, we should Know your yinme.a. 0 your !.. have mentioned that this system is known horn r Transformer learncharacter or tip. e ith Forexperimentalpurposes. Anysizeor as the George Rennie Rail plane Systemof associated. Send sample hand:. ritinrInn voltage,also OdinCoilsanticondensersbuilt Transport, the inventor being Mr. George on plain paper, still, one dollar for eromplete Pricesreasonable.InquiriesSolicited. analysis.Address GRAPHOLOGIST. 308 Stink toorder. Scotland. \\'eare Exchange Bldg., Buffalo, N. Y. A. M. Brown Manufacturing Co. Bennie of Glasgow. P. 0. Box INS Mobile, Ala. glad to give this credit to the inventor. 'January, 1930 Science and Invention What I Found on Board the R -Doi (Continued front page 840) an engine radiator,itis warmed in cold weather and sent into the cabins through air gratings.In warm weather the rad,a- OMR PAY tor is lowered outside of the ship and co,,I air can be supplied to the living compartments. The ship has the usual control car out- .5mi/bleuPla n Is FREE side the main hull, and in addition a chart room above it inside the ship. This is vir- .1 can prove that John Sovaige, trained byme. main tually the "brain" of the ship with intri- $300 a munch! A. H. Bernier. teamed by me. cants 57.000 to 19,000 a year.Arthur DeWalt. craned by me. makes cate apparatus for telling the conditionof isoif MOT. than $400 a month.D. C. Swoop, trained b, allparts makes $475 a month.L. V. Broughton, trained by me, of the vessel and communicating makes $300 a month. IV rate for this book ith the various stations ;instruments are so help you get mart pay... here toindicate thevariousstrainsto -Engineer Dobe which essential parts of the structure are subjected in flight, and when moored to rut' the mast.The strain on the mooring eye is shown by an electric indicator which tells whether the bow is light or heavy and by the strain on the hearing tube of the 'lose mooring the instrument shows whether the ship is bearing down or pulling up on the nose cap. It was my good fortune tofindthe British Air Vice Marshal, Sir. \V. Sefton Brancker, Director of Civil Aviation, in his office at the air ministry in London not long ago.He had just returned from a trip in the giant Dornier IX) -X and he said: "I am very much impressed with the I send you this book FREE in connec- possibilitiesfor ocean travel which this Why work aU your life for smallpay and tion with my offer to train All Tour Tools you at home in drafting. marvelous flying ship has proved to be with little chance for a raise or promotion? Jobs waiting for draftsmen. ass Draftman's feasible"; we naturally turned to a dis- Let me train you for Higher Clan Work and The higher positions in Folding Table cussion of the relative merits of the large Better Pay. Get my Pay -Raising Plan-NOW. pl ints, factories and bust- are furnish. d by ness houses are filled by airplanes and the two big airships, the Fl! send it to you FREE. It wiU convinceyou men with a foundation orig. me when itrain inally as Draftsmen. you on drafting R -I01 and the R-100, which 1 had just and show you a way to builda big future workflit visited.He said "Just how they will be When trained by me. I help for big Pay, on clean work leading to salaries you getajobwithout employed later itis impossible to say, hut of S60-$70, and up to $100 a week salary. charge. Employers of More Pay! it that much experimental flying draftsmen come to me for Steady Pay! All buildings, machinery. automobiles, motor busses, air- competent draftsmen at 160 will be necessary before they can be ap- ships, electrical apparatus, all manufacturing and con- - 870-up to 0100 a week plied to a regular service at the disposal stri.ction of any sort, depend upon draftsmen. straight salary. of the public." train you by mail in your spare time. You keep your Noprevious experience is necessary. You do not need to job while learning.I go. e you an opportunity to earn be a college man or high school graduate. train you Byspecialarrangementthroughthe extramoney. 'til you're in a position and EARN MORE PAY at steady courtesy of Nit-. Robert T. Pollock, repre- work. ALL TOOLS are FURNISHED BY ME. sentative of Lieutenant Commander Charles DennisBurney,builderoftheR-100, Mail This Coupon"FREE" Pay -Raising Plan sister ship to the R-101, T was shown on If You Earn Less 111141MIZZU DOSZ, hoard the twin of the world's largest air- 1441 Lawratawa Aye.. Oto.14-21 mina. ship, 5,000,000 cubic feet gas capacity. Please send me. free of all cost. "My Pay -Raising Thans70a Week also FREE Drafting Book and Draftsman's Pocket Rule. now and I ALL FREE. R-101 Has Frame of Stainless send you "Mv P.1,-Kai.ing Drafting Rook and Draftsman's Pocket Rule -postpaid and free. Name Ate Steel tiyo "You'll gel year ITis quite impossible to realize theti- Engineer Dolbe14-21 ' Address tanic proportions of these tremendous - Looses Bob. tint Lawrence A.,, Cbteari structures, which arc practically of the Pose Woe same size and gas capacity.The main points in which these two ships differ arc in the frames. The R -I01isbuilt on a framework of stainless steel tubing, one Who Wants and a half inches in diameter with forged STUDEBAKER BUICK-NASH!a Sedan TAKE FREE? duraluminum end fittings with pin joints YOUR CHOICE! out of which the triangular girders arc or $2000.00 Cash MARK formed, which latter are used to build the Thousands of dollars in new autos a id grand prizes YOUR will positively be given free to advertise and make STAR keel and the longitudinal beams which run new friends for my lirm.Choice of 'tudebaker or the full length of the ship from stem to Buick or Nash new 4 -door sedan delivered free, or 02000.00 easb.Also Oldsmobile, Pontiac. Chevrolet, Fords, dia. stern, and also the immense circular girder monde. other fine prises and malt will be given free. No work or rings that give form to the hull. problem+ to do.No fine writing required. No words to The frame of the R-100 is constructed make. No figures to add. Bank guarantees allprizes. of four -inch tubes of duraluminum heli- PICK YOUR LUCKY STAR! All the stars in the circle are exactly alikeexcept one. cally wound and riveted. which arc used That star is different to all the others and itmay be a to form the triangular girder work. lucky star for you. Can you pick it nullIf you can. Of mark the different star and send the circle tome at ore. special interest is the fact that anyone of along with your name and address. A prompt'mower c.. these triangular sections may be taken out start you on the way to win the great f2foo.oln freepr... and replaced in the girderwork in about BE PROMPT-WIN$650.00EXTRA four hours' time,iffor any reason Someone like you who will write no. ,ee r..r it S6.50.00 cash just for being prompt, soyou may thank your should become necessary. lucky stars if you send your answer rightoff.No risk. Nothing to buy.Nothing hard to do.Over $70010.00 The R-101 is equipped with five Beard- valuable prises will be given free of cost.Send today and more heavy oilburning compression ig- Iwill show you just how you can gotyour fns choice of these splendid new sedans or 12f00.fet rash,without cost nition or Diesel type engines, 8 cylinders or obligation of any kind.All win plan! A reward for in line of 585-650 h.p. each. four of which everybody. SF:ND NO MONEY.Answer AT ONCE. are placed in power cars on each side at GEO. WILSON, DEPT. lb AUGUSTA, MAINE the 4th and 9th frames, while one isin the center car atthe rearatthe11th frame.The port forward motor at present is only used for speed in the reverse To be sure of getting your copy eachmonth, subs.:ribeto Science andIns ention- (Continued on page 850) S!..511 a year.Experimenter Publications, Inc., 381 Fourth ksenue. N. Y. G. 850 Science and Invention January, l').10.

direction.It was originallyintended to use a form of reversible metal propeller sy.QuickWay SCthat the motor could be used for for- LI,C) ward speed as well, but this has not beenT perfected, and wooden propellers are used. o GetInto Radio Consoles The use of fuel oil, besides minimizing the fire risk, reduces the power cost to about 4,k44,- one -fifth($25 atollagainst $125),although the added weight of the engines will make itpossible to carry but fifty- two passengers instead of one hundred, 44,7Are' as originally intended. A small four cylinder gasoline engine is used for starting each motor and theyalsooperateair --/it Major Rockwell compressors and generators forelectric Train You light, cooking and radio. The R-100 has six Rolls-Royce Condor AT HOME engines of 665 h.p., placed two in each car My new linietica), amazing Mime Study Course prepares you quickly tofill any of the fascinating Aviation jobs. at each side and two in the central rear either on the ground or as a skilled flyer, paying$511 in ear. Win a neck.I train you to succeed quickly, to all one At present they will burn gasoline; of the thmeatnii: of adr nod ground jobs now open and I hut a new method of engine distribution help you to tied your right plate in Aviation. ;aid a fuel gas has been developed, which LEARN PRINCIPLES AT HOME.IF YOU WANT TO FLY- if applied at a later date to the R-100 will 3fy home study course teachesthe principles offlight. allow her performance approximately to When completed I will a rrunge for your flying instruction near your home at reduced lute:.If you want you ran he doubled. The comfort of the passengers come to Da) toll and trait at one of the finestairports. has been lavishly provided for and the Either nay you can nualifyfora pilot's license and a high pay flying job.If you are not eati.ticit after gradu- fittings of the passenger cabins, which are ating I'll refund every rent of your tuition. :Mall coupon entirely within the hull, are equal to die for Free Book and all details.State ave. furnishings on the latest ocean liners.In Maier R. L. Rockwell, /In ima - The Dayton School Air the R-101 a lounge, seating 100, extends of Aviation Major R. L. Rockwell. Dayton SchoolofAviation right across the ship with verandas on Desk A-20. Apir each side from which one can los& cut Dayton. Ohio Adr Desk A-20,Dayton.Ohio. I through windows in the outer skin pro- FREE 4r Dear NIFIFF: 1.11,e BOOK # ropy of FREI.: ROM: on amazing, I vided with safety glass. wayeasy to get into Aviat Ion. A beautiful Walnut Cabinet with sliding There is also a dining room lighted with Name doors of matched Butt Walnut andse- large panels which can seat 50 persons Address lectedJapanese Ashsidepaneloverlays. andcontainingaradioloudspeaker. Accommodates Buckingham,Crosley, Underneath is an elaborate electric kitchen e AtwaterKent,Fada,Sparton andall withdumbwaitertothediningrocm. standard receivers. Ample space for Everything is very light and carefully tie - Receiver, Speaker, etc. signed in every detail.On the trial flight NOW-. Become an_ Write today for Free illustrated folder of of the R-101 the guests were served with allnew styles,including Phono Radio a hot luncheon consisting of soup, roast Combination Consoles. mutton and vegetables, fruit salad, cheese Electra Technician and biscuits and coffee.The crew was By this Aim/sink New Method EXCELLO PRODUCTS CORPORATION dressed all alike in brown dungarees and Train the N E\\' PRACTICAL WAY I 4832 West 16th St., Cicero, Illinois white sweaters with white canvas shoes. I'rspare to alert the tremendous de- The passenger cabins have spring beds, mand for Electro- some with two and others with four berths, Technicians in all branches of elec. as on shipboard.The R-101 has, beside a tricity.Splendid PIN A ONE lounge and dining saloon, a specialall - opportunities. metal smoking room, accommodating 30 IIIG PAYfor trainedmelt. people,enclosed with metalwalls,fire- Now is the time DOLLAR BILL proofed, and fed by forced air circulation to start. to this ad and mail to the isolated from the general ventilation of BRINGS SCHOOL TO YOUR HOME A. ARMS CO.; E. 6th & Euclid, Cleveland...0. over $60.00 yours u Ills- will receive by return mail the most remark- e.r the ship.Electric cigar lighters are pro- H.,. (ilt . I tl to "learn by doing. - mill I. 1930 strap watch.Test it-wear itfora pp 'Cult vided and the room is practically sound- Notby tem. tI . but tt Oh patented new week-if pleased withItsend adollar a,_ proof.This is the first time that it has Board System. Bring,.full-sizeEisqlrlealEquip- ....kly until the "Direct by Mall" prim of eleven ment rightinto your home.Train this fascinating Ilars is paitLOthernise return watch and get en, been possible to allow smoking on an air- no, 11oe,,zi.lsion of engineers of America's .1 r dollar back.White rolled gold plate case. fillP I remember Dr. Gilfillan, who came I ill= finished-newest radium did-ruby as ship. shockproof movement that will get Y., PV over in the Graf Zeppelin, complained bit- 48-PAGE .te on time.New type adjustable link bent lish for both men and women.Just attach terly to me that he could not smoke, and FREE BOOK larto this ad with your name and addre Write Imlay for FREE Illustrated 40 - will receive the most beautiful strap wag (Alters said that it was the one luxury that page book giving full details of how a ever saw by return mail. they missed most. The smoking room and you C1111 become an EI.ECTID)-TECII- _Ant. 110. the lounge have specially comfortable set- NICIAN by the wonderful new 1101115 Shop -Laboratory Method.No obliga- 4 (1 tees and chairs.The general ventilation tions.Mention age. Dept. .21. -4 is by means of ports arranged like grills EXTENSION DIVISION 10 1 and any excess of pressure inside the envelope can be relieved at once.A current ScHco.trct,PlITUR'NG offreshairiscontinuallycirculating 1 through the ship. preventing the accumu- lation of fumes of escaping hydrogen. HESPAINT SPRAY Paint Spraying Brings GOES THE Quick. EasyProfits --11B :2r°,°STOP TOBACCO? does work of 5 brush painters. WORK OF Paints autos. furniture, houses, at Banishthecraving for tobacco as MEN lowest prices, with big profits foryou. woovam,thousands have. Make yourself free f'aus foritsaf-only $20 most hey. Eat) and happy with Tobacco Redeemer, lowest terms brings it. Practically Not a substitute. not habit forming. $21,000.00 for Spirits no investment. andays'trial. Write for free booklet telling of in- Writeforvaluable bulletins Jurious effect of tobacco and de iwiob. For more than six years this pub- EASY TERMS, Hobart Brothers Co., able. easy way to relieve totaling 30 DAYS TRIAL Box SIAI,Troy, Ohio the craving many men have.FREE lication hasofferedprizes QUICKLY PAYS FOR, ITSELF - Newell Pharmacal Co.BOOK $21,000.00for genuine demonstrations rtiriDept. 884, Clayton, Mo andproofsofspiritmanifestations which we cannot duplicate by scien- MODEL AIRPLANE tific and well-known means. BUILDERS Up to the present time not one mani- 2 Ft. Sikorsky-Amphibian eonstr. festation has been presented which by set.$2.75. cliEBORMICEIKEIM ' 2 Ft. Bassin-Marchetti constr. set. even the greatest stretch of the imagi- 40°$2.50. FREE CATALOG SHOWING 200 DESIGNS 2Ft. Curtiss-Army Hawk eonstr. set. 33.00. .,EITHER DESIGN SHOWN. SILVER PLATE 35. EA12 nation could be considered genuine. Blueprints only all full size 50e per piece.3 Ft. Lock- 00 O. MORE 5300 DOT ING SILVER OR GOLD How many more years mustthis heed -Vellaeonstr. set,35.25. 2 Ft.Morrow-Twin- 9 1110. EA 12 OR MORE 55 00 0021 OR 2 Bomber (Drops 5 bombs while In flight) constr. set. $1.50. COLORS ANT 3 LETTERS AND DATE Spiritualists, please glASTIAN BROS. CO. on v.v....is..a.ROCHESTER. N.Y. prize be offered? 52-1'age Catalog 5 rents answer! NATIONAL MODEL AIRCRAFT and SUPPLY CO. 29 North Ave. New Rochelle, N. Y. January, 1930 Science and Inventinn 851 How to Builda Record - Winning Model Plane Relieves By Hi Sibley Pain (Continued front pane 808) Quickly Next set in the rear hook, made of about No. 8 music wire.This is inserted in a pinhole just forward of the stabilizer, and secured with ambroid. Write for For the propeller bearing a piececan be cut from stiffsheet brass,tin, or light Factory galvanized iron.Before cutting, however, punch or drill a small hole for theprop Price shaft. Don't makeitany larger than necessary for the shaft to turn freely. The wing, fin and stabilizerare made from whatisknown assoft"sheet" balsa, or pieces of about 1/16 in. thickness. Here is where your skill comes in handy. These three pieces are sandpapered down to about 1/32 in., or thinner if you dare. Relieve That TroublesomeAilment To do the work, lay them flaton a smooth Write at once and let me tell you how to relieve thattroublesome ailment with Infra- surface, such as a drawing board and with Red treatments in your own home. The Campbell Infra-Red Ray Lamp throwsout a piece of fairly coarse sandpaper wrapped mild beams of Infra -Red Rays which penetrate deeply intothe tissues and bring a over a flat stick sand them vigorously, but soothing internal heat-best, because it works where the congestionis, and restores active withcaution. The edgesshouldtaper blood circulation. Medical authorities say most ailmentsare due to congestion-relieve slightly.Apply ambroid to the tail slots the congestion and you relieve the ailment becausenature itself does the healing and insert stabilizer and fin.The latter through active, normal blood circulation. must be clipped diagonally at the bottom with a pair of sharp scissors tofit the Why Suffer Needless Pain? diagonalslotprepared forit. They Are you troubled with Sinus Irritation. Sore Throat, Neuralgia,Brunch: t Rheumatism, should be at right angles to one another Neuritis, Lumbago, Tonsilitis, Catarrh, Ear Trouble, GallBladder trouble or similar and exactly in the plane of flight. ailments? Just let me send you this wonderful lampon approval. Use thirty days according to directions and see if it does not bring After the wing has been sandedto the you wonderful results. requiredthinnessroundthetipswith HarmlessYou or anyone in your home can use thelampon instant notice. scissors and score lightly on thecenter Itison an adjustable stand-easily carried to any room-easily line.The gentlest pressure will then break placed in any position. Leading health author ties recommendit. Letters from satisfied itsufficiently to form the dihedral angle. users everywhere tell of wonderful results. Just a fewtreatments will surprise you. First cost only cost. Connect with any electric light Better hold the edge of a ruler downon socket. the center line when breaking. Nowpre- Easy PaymentsShipped post or express direct to you pare a "cradle" as shown.Note that the from factory at lowest cost. Don'tdelay-if you bottomisbeveled both ways tofitthe or some friend have some troublesome ailment. Write and letme send it at once. dihedral.Apply ambroid and set in place, securing it with a steel pin and propping Get Our Book On Infra -RedRays up the wing tips with blocks so they are This book quotes leading medical authorities and hundredsof users. Mentionyour 7/8 in. above the center.Let the ambroid ailment when writing and we will send you free valuablesuggestions on how to treat harden for half an hour or more in all it with Infra -Red Rays. Thirty day trial period. casts. WILLIAM CAMPBELL CO. Dept. 1050 ALLIANCE, OHIO A single soft balsa rib in each wing tip holds the curve. Apply ambroidto the curved surface of the rib.layit on the table of drawing board with the flat side SEND FOR THIS down, and clamp the %Ong tip downover it by means of curved blocks pinned down as shown.Do not install the second rib FREE BOOK until the first is dry. OF SELF HELPS Forthepropellerselecta straight - grained piece of soft balsa 'A in. by F,;iin. New practical working method: for Aviators section and cut off a 7 in. length.Mark Radio Men, inventors, Engineers, Nlechanies, outlines of prop blank, as shown,(.\ Automobile andBatteryMen,Electricians, $1900 to $2700a year Contractors, Carpenters, Painters, Decorators, Long N and whittle away the waste. GO EASY ! .%rtists. %a all,a1F. 1%,t;% .'.4 it,!.,-T Advertisers and other technical men. trams with all expense. n'aid. 110101. NO nooks Next bevel the blades with light cuts until Over 200 hooks covering practically all kinds' about the fattier. of mechanical work.Write your f rre copy they are about 3/16 in. thickas in( B) today. MY FREE BOOK TELLS NOW ',.`a,c';'!!`,',Y5 Pi!!rr and, (C).For greatestefficiencythe Office Clett. city Mail Carrier.It. F. 0. Mall canter. Postma.ter.l'Sre,t Ranger. Internal Revenue, and numer- blades should he curved,thatis,front FREDERICK J.DRAKE &CO., Publishers ate: other the paying Got ectinient poiitions.If you are a citizen. bctiveenII and side convex and back concave.This is 510- 179 No. Michigan Bled., Chicago year,. you can get a Coserti- Civil Service . I'll shun you how.Gil tho done by laying one blade flaton the edge tarts in my 4$ -pace booklet.It absolutely tree.Write of the workbench and workingout the PATTERSON SCHOOL, A. R. Patterson. Civil Service (sport. concave or hollow side by light cuts with 901 Wisner Boinc. Rochester. N.Y._ arazor-sharp gouge,orcurve 3/8in. Wand This Model Airplane chisel (I) 1.Finish with a piece of sand- YOURSELF paper fastened to a tapered block that is Choice of1200;:; rounded atthe bottom.A splendid job can be achieved in this manner. Newest.. Make the shaft hole witha steelpin, taking care thatitissquare with the blades and exactly in the center. EXACT REPLICA RADIO 3 -ft. model For the shaft, "S" hook andrear hook use about a No. 8 music wire, or what- BELLANCA "Columbia" FULL SI/,i' PLAN WITH INSTRUCTIONS VALUES if ever you have on hand fine enough and fete Materials for Assembly. Guaranteed still strong enough to carry the load.All to Fly. catalog. 1't1151 with 401.1 r- wire isheldin place with ambroid. Send for your copy of our 56-page booklet ing values in ,reengrid A describing 24 living lets and comptete line radios. 245 pushit,iltaudi,i, thin brass or tin washer is ambroidedto of parts for model builders. radio consoles. kits.parts. This booklet Guaranteed merchandise at the prop hub. of 19c. is mailed to you upon receipt ahr,h-ate Use a double strand of in. rubber Your dealer can supply you, if notorder direct. EL. band. U. S. MODEL AIRCRAFT CORP. WESTERN RADIO MFG. CO 397 Bridge St. Dept. A Itrookl) n, N. Y. EMI wLAKEST. CHICAGO lee. Science and hive?,lion January, 11)311 Is Space Curved? By Donald H. Menzel, Ph. D. faRiciT (Continued from rage 800) curves.To say that space is curved, then. in 12 Weeks is simply short -hand for saying that the geometry adopted by Nature isnot Eu- and Make 50 to150Weeldy. clidean, but of a more complex type. Many ill tome ,41 . ., I:. . 1.! youcan ;, statements of Euclidean geometry are un- highlypoolr iertricaljob paying $50 to $150 s true, or perhaps only approximately true .reek and make good. LEARN ON REAL EQUIPMENT-NO BOOKS TheIDEAL in the newer geometries. You have learned Youworkailhespertin -limbosonfull size that three angles of a triangle sum up to motors.generator..Willett,,so itchlontril,arena - live., mill home Amencan Eagle 180°, two right angles.The proof of this NO EXPERIENCE OR EDUCATION NEEDED theoremismade todepend mxinthat It14 easy In learn ElectricityInlily Practical work The Most Advanced Development in shop. No books to read.Ni, dry lessons to learn. famous "parallel postulate" you just men- You learn by doing.No lower how strange Etc, Flying Model Airplanes tioned.Consequently itis not necessarily Welty Is to you, I ettarantce that. when you graduate you'll know electricity I "A to X" andif Wing Span: 26 in.Weight: 3tioz. true, since the postulate is only an assump- you Mal you cannotfill a big pay Job.I'll refund AN entirely new, light -weight, fast -flying every penny.SIAM COUPON PIM FREE BOOK Model; distinctive appearance, realist', tion. AND SPECIAL LOW TUITION OFFER. In flight, unique in construction details. P-If Imeasurethreeanglesofa .1. It. NIcSweeny. Pres. Balsa wood fuselage,withspeciallyd - triangle, add them and find the sum equal signed aluminum bulkheads; built-up wines McSweeny Electrical Schools to 180 degrees,isthatnot aproof Dept. E17.ft With ready -formed ribs; removable tail as- 1815 E.24th St.. Cleveland. 0. sembly.Finished in tern color decora- Euclidean geometry is correct? 21,1 MadisonSt.,Memphis. tions.Just the Model Airplane you have or lec n wanting; simple in construction, and R-The oldermathematicianssought Tenn. a reliable, fast flyer. to found their theories on logical grounds (Address schoolnearest you) Construction Set: $'1.10 objectto I. H. MeSWEENY. Pres. alone. They might,possibly, McSweeny Electrical Schools Entirely Assembled Mod..i: $5.00 pour method.But if you try it out onall Dept. E-17.11. 1815 E. 24th St. Cleveland. 0.. or 263 Madison St. Builda3 ft. Flying Model of the :izesoftriangles andfindittoload Memphis. Tenn. FORD Transcontinental MONOPLANE rig. -4111,1y. Ishallacceptyourproof. Dear 51ar:Send me a cope of your big free book thefinaltestof anytheory an ELECTRICITY;al.e,tetall.of reinatlatble A perfect. stale -model of the .\ilrrall. tuition otter, and radio tsini .c. giant airplane: nowin use forcomet -to -roast passenger NAME transportation.Any boy can buildit;the IDEAL, com- ADDRFSS plete Construction outfit runtainsallparts,fittings and materials, with complete tSVN STATE... plans. diagrams and build- a. ing -flying instructions. The Model Is goat anteoil tofly when correctly built. Com- plete Construction Outfit 98.50 /0t: If.11,4r1 .4111.10111,. P. In sod Nttpplirs af 1,01,1 141 Tog. Sy,', Goods and IlorthroirStores. 11 uotobtoinublr its your locality. your ord.,trill be 1111,4 llowtoGatheMostOutoF 1hr foamy upon terript u! prier. 1.111 Prier rent hiuhrr Ire .1 111 Pt urn%colt,.andin CI111,111,11 Plans for Model Alrplanes-25c Complete. ariucole. h -size Plans. with Building -11Y MARRIAGE lop Instruct 1.itis,for any one of the following 'Models. sentpostpaidfor2:1c: FORD 5IONOPLA NE: New Amk-Pai isNinimplane: FIIhh ER 510NOPLANE: Daringly .1 Biplane;Doll AY] LLAND Biplane: NC I MEN N., al ; ItIcrlitt. Taut* or Mention \Muno- Different pl.0 CecilIII obiEat,. Catalogue included free Fig. 7.What cvill one see if he gets to Ifrom any other publication. i. 011 of our big intimate Magazine is (.4 -page Catalogue of Models. Parts and Supplies for thegery end ofEinstein'slimit strictly for yon I Coot be de- Builders -5c spare looks intothe d istanee socribed--enustbe man! No and Fake, so Fads, no Fiction, no IDEAL AEROPLANE & SUPPLY CO, INC. beyond? Foolishness-but surprisingly babe original, eourageous, and lOtir Sale.t Name in Model Airplanes for 20 Yeats" valuable to f,11. Devoted Ger- 22-24 West 19th Street. New York City totaly to intimate subjects in should be its experimental check.Liter- which NORMAL MEN everywhere are individually inter - Llko a Mani- ally, the word. geometry, means to measure es ted--such as Physical Fitness. Personal Hy - kin, lt turn. ensue and Prevention, Virile Manhood, Mae- tto. be ro theearth. though the originaldefinition culinity, Nodal and Married Life, etc. Thous- SPRUCE STRIPS nirti odd appears to have been lost sight of by man ands of coon would not tell their movie. for mak. overt. money. You will know WHY when you awe thine Plain... All sizes and quantities mathematicians. It.I I you are married or ever iszpoet to be, both youand wifewilllensfit-for Perfect size and finish Here is a very accurate surv:ying in- IT DOES NOT DUPLICATE ANY Write us and save strument.When properly adjusted.itin OTHER MAGAZINE but actually doala with capable of yielding- an accuracy of much vital subject heretofore nut rally dis- AIRPLANE SPRUCE CO. cussed in print. Endorsed by men's 91tusieideut. better than a second of arc.Summse we And edited to meet a long -belt need. 4046 N. Keystone Ave., Chicago, Ill. No book an possIbby he spend the rest of the afternoon in an ob- as satisfacton. servational test.I am sure you mil! find CUT THIS OUT, *end with itinstructive.Let us measure three tri- wti tn o6w bfor r b6 ckm Dumber. bbo. angles, first a small field half a mile or It so, our els MAPLE (AOP7Stg.'", tre 100.., NU - trim.> SffitiatactIon enarantiled BIG -PAY JOBS in so on a side, then a triangle with legs six MAN MAGA- iviA::::.scrily refunded. or eight miles long, and finally oat whatZINEIsyoulust ndl Act Locoma Pub. Co. ELECTRICITY twice a: large. mewl Dopt.R0 Battle Creek.Mich. Amazing new method. Trains you quicker and better. Motion Pictures in your own home (,1..1.111:-Vhitt?, and in tht much-, $60°'' make every point clear. Genu- joiermi,siini while the three friends COIN - most nut miss thy (Muer offr r. ine DeVry motion picture pro- 1)10 C the measurements.That evening to jector at no estra cost. Thou. sands of feet of film furnished. we lied them assembled to discuss We pledge to give you training the results. 5150° and employment service ne..- essary to secure a better job at bigger pay or refund money. INEEla Get full facts. No obligation Write quick while offer lasts R-Now letussee how westand. \\ hat were the figures on thatfirsttri- angle? Motion Pictures P --(Referring to a slip of paper) Train You QUIM The three angles were as follows: National School of Visual Education. Dept.1.3.% 17' 20" 537 S. Dearborn St.. Chicago. 44° Send book. "The Film Way to Bigger Pay," with i15 12' 13" facts about this crew, easier way to master electricity. 60°30'27" WHEN your spirit craves some rip- Name Age roaringstories of he-man adventure, St. or It. I) 4 180° (10' ;?0" just ask your newsdealer for the NEW City They sumtiptoexactly 18(1 degree, 4 BRIEF STORIES State. ... There now, isn't that good enough protti Ai,eri. a's Grcitc, Al.. cattier Stui ies by R : Ye:, vou scent to have proved that Gee. (test Write, MAIL THIS COUPON NOW! this first triangle fulfills the requirement: January, 1930 Science and Invention ofEuclidean geometry.But the next? l':(reads) 39°42'17" 61°08'10" TRAVEL 79°09'34"

This gives 180°00'01" ON What? There must be some Mistake. No, I've added it correctly.That's queer, the angles sum tip to one second more than " UNCLE SAM'S" theyshould. We must have measured theta wrongly. R-I'll reserve comment.What about PAYROLL the third and largest triangle? P-(reads) 54° 18'48" 49°22'36.5" 76° 18'38"

The sum is180°00'02.5" That looks worse yet, two and a half seconds too large.What do you suppose can be the matter? R-(smiling) The situation, you know RAILWAY POSTAL CLERKS is rather amusing.Von must have forgotten 3our words of this afternoon. You were the one who suggested that we test Commence $1900 Year the sum rule for triangles by actual mea- Many other U. S. Government Jobs surement.Now that the measures don't open to Men and Boys 18 up fit with your expectations you are ready POSTOFFICE CLERKS CITY MAIL CARRIERS to throw them aside for a theory developed RURAL CARRIERS GENERAL CLERKS front a postulate that cannot be proved. PROHIBITION AGENTS CENSUS CLERKS These are all steady positions. L-I see the14)gic of your point ofmonths every year. U. S. Government employees get their pay for full twelve / viewallright. . \schildren we were. / FRANKLIN RAILWAY POSTAL CLERKS / INSTITUTE perhaps, too impressed w ith the apparentRailway Postal Clerks now C0111111ctiCe at$1901.1 a year, being paid on the Dept. 0.177177 logic of I and fifteenth of each month. first Euclidean geometry. suppose 879.16 each payday. 'heirTI payisquickly in- // ROCHESTER, that is the reason we are so loath to ac-creased, the maximum being $2700 a yi.ar.$112.50 each pay day.They get / N. Y. cept anything else. extra allowance for hotel expenses when away from home.Early examinations are txpeeted. /Rush tomewithout R-But that is no excuse for not keep- PAID VACATIONS charge(I) fullde - ing an open mind. solutionoftheposition Railway Postal Clerks, and all Government employees,get a yearlyvacs-40,N checkedbelow: 12) Pres L --Rutwhere'sthecatch? Surelylion of 15 working days (about 18 days). Onrun; they usually work 3 ropyof32 -page.Illustrated days and have 3 days off duty, or in the same proportion. ,.,,'bok. "flow to Get a C. S. Euclidean geometry isn't that far wrong?off linty and vacation, their pay continues just During thisA. coiernment Job"; 131 Tell me as though they were c'T 1 R-A couple of thousand years ago, working.When they grow old, they are retired witha pension. 4,.. to get the position checked. suchmeasurements,aswe have made Railway Postal Clerk ($i900.$2700) CITY MAIL CARRIERS-POST OFFICE CLERKS 61 Pest Odin Clerk couldnotbe explained away soeasily. Clerks aid Cirrier, get (81700-92300i $1:110 the firstyear regular and automatically in- ..,..City Mail Carrler Then everyone thought that the earth \vas crease $1110 3 Near to $2100 With further In'rease to $2300.They also hair 4.7 ($1700-32100, I:,,t.),' saeatIon.Examlnat11111S are fretiliAiti livid. flat-a plane.\\:e know it to be spherical. tiluic.cssaty. City residenceIs +sr...RB.oeukrkaelephlearil Carrier (92100-$3300i Hence instead of measuring the angles of GENERAL CLERKS ($1440-$1920, a plane triangle, we have actually been (Open to then or women IS oruser) / ..General Clerk ($126042100) Salary $12.10 to $2100 a year.Pleasant (lethal workiii Agent surveying asphericaltriangle.likethis del.:aloft tit, time sartoue / Prohibition (82300-92800) oanao. amid offices at Washington.II.C.. and throughout the / (Fig. 2t.The treater our distances, the The toil Census uill mean bundled., of appolooneol. / Name larger would be the discrepancy between Get Free List of Positions / our figures and your theory. FILL OUT THE COUPON.Tear It ce tillim.IIIt TODAY / P-Then, for all practical purposes, the - NOW. / Use this coupon before you mislay It - small triangle may he considered a plane. R:If by -practical.' you refer to the particular surveying instrument we have used, the answer is yes.But if we had 150To 300 MONTHLY FROM ONE DAY BATTERY CHARGING s..: Bug Pr -StMaktng Business an instrument a thousand times more ac- OA L'..-,-rs Requite. small space and prac- curate- tically ne investment.Monne can su.,esAully operate. 30 Charges Joliette,. In I.3 the usual iliac al1a the cost. DAYS L-Uut inthatevent we could never 14.4.41, Every car owner a customer.'rhe mitt One Day Battery find a perfectly plane figure? 61.-O;..... t charger x111 PU forliself on easy monthly payment FREE plan with pract7ealle no eXperi,e 10 par and bring you TRIM R-Which would only go to prove that a Plana -woe pmnt besides.Write for full particulars in ON.tosoAm Bulletin M NOW. HMI BACK geometry is little more than an abstraction. ! HOBART BROS. BOX S -I3 TROY. OHIO It deals with plane: and lines, which have D0ARAN111 no c4)noterpart in moure.Sometime ago, ONLY 316 MONTHLY -MORE T AN PAID BY INCREASED PROFITS I proved. I hope to your satisfaction, that there is no such thinz as a straight line. By much the same type of argumentI could prove thatplanes,also,are non-"Dependable 'B' Battery Power" existent. Non-Destrint Re -chargeable,EdisonElement The ancients thought the earth was flat. flatteriesf..rLong :Std Short Wave Receivers. By such measurements its we have made 100 volt, $12.0o: 140, $17.00; 180, $24.111.l'rices /0425 Wm include dry TRICKLE CHARGER.All batteries )15 Chatging Batteries el today,onlyoverstilllargertriangles, shipt.ed dry with solution. Send 110111.111cy. pay have the olderbeliefs been overthrown. sman.Also, "It" and "A" Battery outfits But the change was a gradual one.The operating front 32 -volt systems. boo StartsYou Let me show you he w explanation which. to the ancients would to make big money have seemed most bizarre and artificial, right from the start. seems quite natural to us. I've prepared a FREE P: Iconcedethat k: book explaining all details.First nothing material week's profit pays for all equip- can be perfectly plane, for matter is comment. You can get all the battery posed of atoms. tiny particles whose shape charging business in your community with my is by no means regular.It would be as Service Station Charger-it's years ahead of ordinary chargers- handles 50% to 70% more impossible to build a flat stir face of atoms batteries. I explain everything-start you in a as to make one out of a stack of cannon business of your own and put you on the way to balls.although,sincethe atoms are so big morey. Write for FREE BOOK. much smaller,the cracks between them C.F. HOLMES, Chief Engineer, Dept. L will be invisible to the eye; nevertheless Independent Electric Werks 4912 North Clark St. they are there.(Fig. 31 But ourin- Chicago,III. struments seem to have proved only that the earth is round-rather than that Writefor our interesting booklet.See Jay space, Battery Co., 911 Brook Ave., N. Y. C. FREE BOOK -Just Out Science and Invention January, 1930

itself,is curved.Surely there are inueli flatter surfaces in nature than on earth's! Suppose we build our triangle out of lightrays. What then? Hereisno question of irregularity. R-It is true that our measurements of Wouldn't this afternoon did not prove that space iscurved. But they didindicatethat Euclidean Geometry cannot be applied to You Like to curved surfaces.I am not sure that your last suggestion helps. Light is made up of waves. An actual beam of light would look something like this.(Fig. 4) The Have Your These arrow throughitindicatesthegeneral path of the beam in space.It is that which you wish to call a straight line. Own Books You'llagree with me, I'm sure,that we've met a very practical difficulty.Ve Tell need a measuring rod to explore space Business? with and not a single one begins to fit the specifications laid down by Euclid. HO I am most anxious that you allow me ToHAVE an extra, inde- ,Big Auto Books W to build triangles out of light rays, since Repair any auto fault,learn how now. You can do it pendent income? To work easily in this new simple way.These tire big automobile that is the only means I have of survey- whenever it suits your conve- hooks are the most interesting. the most practiral books But, if you recall, the path we have ever published on automobile construction. oper- ing the stars. nience?Make a host of new ation and repairs.Brimful of farts. photographs and ex- of a light ray is not a straight line in the friends and gain valuable ex- planationsso easy to understand that anyone ran learn how to repair auto faults in almost no time.Over 2,000 sense you probably imply. A ray follows perience from contact with pagesfull of diagrams, data sheets and everything else the path of least resistance, called a geo- Have money neededto make anyone anauthorityonautomobiles. other people? Whether you scant to qualify as garage owner. auto repair desic. which is about as close as we can to buy the 101 things you've expert or merely wish to know how to keep your own ear possibly come to the absolutelystraight always wanted but felt you 1011% efficient. you willrecognize the amazing value or In that case geometry becomes a thesefivebig book:,elocelally on our no money offer. line. couldn't afford?Know the All Shipped FREE study of the path of light rays in space, happiness that comes from A very liberal planofdistributionbring;these hooks is, perfectly definite to you for examination without Otte cent of payment to us. which of course a doing something really worth We don't ask a cent of you. but ship the books free.Look them over, read them as much as you want to. note the while? splendid photographs and drawings. and thenif you decide you want them.send only $2.510 and then 93.00 a Then our easy money -making !tomtitunlit only $24. Ms paid. Thati< all.Nothing nodeI,. pay Their nu 11011.1 ob I i plan offers a splendid oppor- American Technical Society Membership Free tunity to gratify your desires. e include a ccrt ideateofmeniherdilpinthe American Technical Society, which entitles you tofree Hundreds of men and women, ...siltation with IS expelsfor one year on any subject young and old, 95'; of whom rr lal logtoautomobileeltl'ineeting.You can Writeor bile any time fur specialInformation.Answers will be were inexperienced beginners :scat promptly w Shout cost. when they started, are earn- Find Facts Quickly You One of the best thing. shoot these ing substantial profits. book. in the Jiffy Jiffy Index ital facts at sour longer ltin can also.All you need is a to read the book. through: you don't hereto You don't have spend long boors over them. 110. 111.1 rn- few spare hours to take care toread Ore .111.11,00 to pot your finger on the informa- books through; tion wantd in a jiffs. of the new and renewal sub- theindexen. Don't Hesitate scriptions for Science and In- aisles you to There are no strings to Wm once-it means Fig. 10. Did you ever try to fit vention, Screen Book, Radio (wt yourfinger joist what it says. Send nano.. and address... n theinfor. the eoupon and all of the hr a bi. hook, will a fiat map to a globe f 1110' News, Aero Mechanics. Plain Milt Ionwanted he sent you. Remembrr. one hut rho se ease sou an e or helpnu to Inajiffy. totiot o.b . and concrete problem. When We point Talk and our other maga- American Technical Society, Dept. A -I25 our telescope at some distant celestial ob- zines. Drexel Ave., at 58th St.. Chicago. Ill. ject,itis naturalfor us to think of it k.-send Menton your free I would like to look at the five big auto 1 will as being in the direction it appears to be, one..I will pay the fee delivery ch: ram.If I like theta I IMMEDIATE stool ,oult2 when 1 have red the books 13 dayadd then It a month as at A (Fig. 5), when in actuality, itis price of only 324.00 is 'mids. .once. hie I will ro- tor..outil ft,theepeehd hooka tyootr eternise. Yew are to include, w it hoot chore, b.. at B. with the light traveling ina long PROFITS con...ITing membership aertifa, ate its the Atomics.. -1,1112 ir of society. curve. Nn one I'-Then should we not measure along You begin earning money at once-the very first hour you Address the straight path, ()CB?(Eye=0). R-You might like to-but our measur- start. Besidesliberalcash Employer's Name ing rod, the light ray, refuses to conform commissions,youalsore- Ensp:ssyces Address to your path.Remember that its geometry ceive monthly bonus checks. limits our problem. If you feel at all interested I.-Then should we not getabetter send the coupon below.It measuring rod.: costs only a two -cent stamp, R-I am perfectlywilling-but show but may lead to a substantial me a better one? we not agree that income.We're so sure you Astronomical and Terrestrial See Trying to will succeed that we supply TELESCOPE Land light is the best we can find? Magnifies 30 Times Games. Ocean make our rods behave according to Eu- everything you need free of Scenes, Enlarged clidean standards is like squeezing a num- charge. Every day you delay 30 Times! a number six shoe: oppor- .., ber eightfootinto isa money -making ,,,,11,L41,111:11.11{ for lorio. it may possibly be accomplished. but the tunity lost, so Ad...stable bracket and Price Our mea- I rtt.I 30 Only game isn't worth the candle. 52.95 surements would be meaningless if wedid.

Rouse of 1, lookingat Fire Days' Free Trial because something would be distorted by Mail This Coupon Now °err. Enloe, bathing only.1.00 now. Pay there about the hem.? iew. :reat for trie balance 181,5 oboe postage, the operation.What is ,nd soy:ice,Mnde like when penman delivers.lacer es- ve.if not Jelialsted. straightlinethatisworth keeping, tele/woof and moires will o,lotioded. pecially sinceit has no existence outside The lllll Publications, Euclidean geometry R. B. SPECIALTY CO., of our own minds? Dept. 25111.M, EARN 510A DAY describes the world as some people think Dept. A335 381 Fourth\e., New York, N. Y. Charts 2:4 to look al the moon "0 E 3rd St..Cincinnati. 0 it (night to he.Relativity takes the world asitis. The ancients believed that the Without obligation to me, please send me circle and straight line were sacred. Hence full details of your easy money -making plan. the planets ought to move in circles.They don't. Thereisa strong divisionbe- $15 tween turgid and reality. NAME Electric Drill I.-Why should light rays travelin a I,in.SteelChuck,key STREET operated. Universal Mn- curve? ter. sturdy tool for wood or metal.Fully guar- ask you why should they travel in anteed.Postage paid. a straight line? STATE I CITY GEO. M. STUDEBAKER, Jr., C, South Bend, lnd. 1.-It seems much more reasonable, 512 Citizens Bank Building think. January, 1930 Science and Invention 855 R-When you sec a fish in thewater, it is not in the directionyou are looking, but below it.The light rayisbent on leaving the water.(Fig. O.) When I Learned L-I stillhave a question. Millions I fspace isfinite, and every straight line becomes a circle, what lies beyond the largest circle we car, possibly draw?(Fig. 7) of Men Sufferwith This k-That question alwayscomes up. and has puzzled many people. When Columbus maintained that the earth was round, his opponents sought to disprove hisstate- ments by asking if men walked on their heads at the antipodes.Always the ques- ciao of the opposite side of theuniverse! Gland The ancients supposed that the flatearth was 1)(11111(1ml by high mountains. When you talk about the "end of the universe' you presupposesome sortof boundary there, like the mountain -fringed earth.You have the idea that the biggest Disorder circleactually bounds something. That when you stand upon ityou will be able I Determinedto to look out into the beyond, muchas a man standing upon the top of one of the mountains supposed to encircle theflat Bring Every Man theNews earth, might have done.(Fig. 8). But the earth is notflat.There is a definite limit to the size of thegreatest of This GreatDiscovery circle that can be drawnuponit. But when you stand on one of these circles. the equator for example, willyour next FOR many years I was a directing executive of necessity of the surgeon's knife in one of the larger steel concerns in the Pitts- operation. a painful gland stepprecipitatey.nlintothe "beyond"? burgh district. Then came an event that Others tellof relief afterallother (Fig. 9.)There is no gaping void. caused me to quickly resign from this lucrative methods have failed. Many say they feel20 years position with its assured future. younger -relieved from the torturous and painful The same is true for the world,except For some time I had been consulting conditions that often make lifea burden for men that the curvature is three instead oftwo with regard to certain manufacturing formulas.a scientist of mature years. dimensional. Are you aging too soon... getting up 5 to 10 Inthisuniverse,as upon One day, after such a discussion in my office, thistimes at night ... are you on the down the earth, there is a circle of maximum man said, "You have many men working foryou. grade, half - Have you ever noticed how manymen seem to living, blue, depressed, subject to chronicconstipa- size-but it does not bound the universe suddenly grow old, go all to pieces in less than tion, chronic fatigue, backache, andweakness? a Then it would give me'great pleasureto tell you, too, any more than the equator bounds the year's time when they reach a certain middle age?" how this scientist's discovery earth's surface. I told him I had noticed this in manycases.Fur- can be used in your Like the earth, the uni- ther I said I was very much interestedas I was own home with the understanding that unlessyou verse is finite and .unbounded!* nearing 40 myself. feel its amazing benefits withina week's time, it L-I finditdifficult to picture such "Prostate trouble is the answer," he said. costs you nothing.America's most noted sani- a "That hardly seems possible," I replied. "Why, tarium has advised it for home use. universe. When you getaway out there on I know of very few men who ever had that dis- You owe it to yourself to act atonce.Send no the other side of the circle, what willit be order." money.Simply mail the coupon at once.W. J. like? "Yes, most men are like you-they know little KIRK, President, 4525 Morris Ave., Steubenville,O. R-I warn you.Do not try to visualize about the prostate gland-yet highest medical If you live West of the Rockies, address The itfor it cannot be dune. authorities definitely say that nearly 7 men out of Electro Thermal Co., 303 Van Nuys Build- Your difficulty, every 10 have prostate disorder after a certainage. ing, Dept. 45-B, Los Angeles. Calif. however, is quite obvious, from thenature Literally millions of men have prostate trouble In without knowing it.Some confuse their trouble Canada. address The Electro Thermal Co., of your question.Itis not an inability with kidney or bladder derangement. Others think Desk 45-11, 53 Vonge St., Toronto, Ont., to comprehend the regions ofspace im- that they are aging prematurely -that pains in feet, Can. mediately surrounding you. Your mind legs, back, and head are merely the result ofad- staggers only when you insist on trying vancing years and so do nothing about it." W. J. KIRK, Pres., Then he told me of his discovery, a simple,easy to visualize both the neighboring and dis- way to stimulate the prostate gland --and how he 4525 Morris Ave., Steubenville, 0. tant regions simultaneously. had placed it in the hands of physicians and afflicted men for conclusive trial. The results had been even Please mail at once afreecoos. of the booklet, "Why L-Just how does the question arise? more satisfactory than expected,in some cases Many Men Are Old at 40." and all detailsabout 1:-The space you are familiarwith- almost miraculous. the new treatment. Can not obligated inany way. that bordering the earth-isso very nearly He ended by saying, "Money and business experience is necessary to bring this discoveryto Name Euclidean (flat) that your mind refusesto the millions of men who need it, at a costevery- work any other way. one can afford. You are just the man." You know, of course, that it is My decision was made within a few days.To- Address impossi- day I see that decision rewarded a thousand times ble to map a curved surfaceon a flat sheet over. of paper, without distortion. Thousands of letters come to me from men Lets try to telling of relief from most distressing conditions. City State paste thisflat map to that globe.I lere Some tell how they have been saved from the we arc at New York ;paste that. point on first.It fits pretty well, doesn't it, in the neighborhood of New York? But Introductory look!The farther we go from wherewe Otter are the more I have to fold it and pucker ONLY my Euclidean map in order to make it Nickel.Brass. curve round the globe. Copper. Silver, Make $150 to $500a Week Geld. etc. N. experience required. $6.50 Do Torii OWN Eleetro-Plating In YourHome. Garage, OMee or Place of Business.Electrically Deposit Metal ---Nickel. Plus Postale Figure S hearsthesamerelationtothe Brass. Copper. 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AGENTS and DEALERS WANTED EVERYWHERE.and Thousands in Serviee since 1924 P. JF. BA TENBURG, Dept. 126, RACINE, (Continued front page 815) WISC. makes for a stronger job than just halving SCHOOL Education them in,the divisions being fixedin V ante - grout es as at Fig. 6. The ornamentation on the cabinet consists Here in 15 wonderful texts is of rows of qt-incli turned beadingon the IGHyour complete High School Education. Every subject taught by fascinating 'Question and Answer" method. edges of the sides and top, anda fret -sawn Now need in 12.000 high itchools.Certificate awarded. It's fun to learn this easy inexpensive spare -tine way. Greatest bargain in brain (CoMpletf (plywood) ornament similar to thatshown power. atFig. 7 on the top of the back, Send for Free BookFind oat how YOU can quickly prepare for bigger with a pay and social culture. Send this ad witlan en; 1 85 1;4 -inch turned button mounted address for FREE booklet, "What a Hie School Education Can Do for Me." 9, upon it. High School Hons. Study Bureau, 31 Union Square, Dept3791 Now York, N.Y. y nos January,1930 856 Science and Invention How to Prepare Dyes and Pigments AVIATION FORINAIINI YOM Page 810) cooling, the sodium salt will crystallize in the form of brownish red needles.Some- times crystallization may require along

_ f time. ,_ To prepare ammonium eosin placesonic (Math ./9Lecture Send eosinin a small evaporating dish and cover taug t at home " Co/viers14 No Money with strong ammonia,After five or six hours the eosin will have been converted study airplanes, motors, meterology and Every foreman, factory worker, man- into ammonium eosin.The dye canbe ;ill aeronautical subjects just as taught in ager and ambitious mechanic will find a filtered off and dried. the famous Universal Aviation Schools. gold mine of inside information in "The Intheprocessofdying the dye The Univer- Modern Foreman" by Robt. 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Business Law, the Foreman as"Top the process of electrolysis.The apparatn- -olloors Extension II nne IV Goon., Sergeant" Factors of Success, Leadership, What is isarranged asthe diagram shows and "Labor," Time and Idleness, Knowledge is Power, `same "Morale," The Value of Mistakes. connected to a source of direct current The solution for the apparatus is made SPECIAL SALES PRICE dissolving some potassium sulphocyanidein "The Modern Foreman" has 297 pages, quick reference index, many tables, diagrams, illustrations and water. As the current passes, yellow cloud - forms; big type, easy to read and understand; rich of thedye are formed and settle totlx- binding, gold stamped. Size 6 x 9 x 1 Lf. Neg. price bottom of the container.After a shor, $2.50. Our special sale price $1.98. Send no money. NEW SCIENTIFIC WONDER -441W Satisfaction guaranteed.Mail this coupon TODAYI time the dye can be filtered off and dried. - en im mm om, im awlRAY.CURI° GREGG PUB. CO., 20 W. 47th St., New York, N. Y. Send me "The Modern Foreman." I will pay post- Tricks With a Phonograph man $1.98 and postage on arrival. My money is to be r..flinded If I am not satisfied. (continued front page809) 104 reverse the direction of his foot, then im- 3-25c Name BIGFUN mediately does his hand cease to turn the Ytelar.pot tit lc ?tauI toil, . -I BOYSStone. anyt See Bone,inFle,h Address reciird. FREE-PKG. RADIO PICTURE FILMS.Take, pictures without camera.-You'll like 'em."I pkq. ea. 25c order. Now for Fig. 4-little Junior is playing MARVEL MFG. CO., Dent. 113. NEW HAVEN. Conn. tricks on Grandpa.Junior holds the cover ofabread pan-a reflector of sound-and he can thus project a beam of sound in any arc valt; direction that he mings the cover. Newest_ Psst-Fig. 5 is the "hug."The fellow VAN NORTON kneeling and blowing rings has offered to demonstrate that there are always "acoustic MURDERS RADIO forces- responsible for the propagation of sound. These forces-so goes the argument VALUES -can exertan interference -torqueupon wEs,®/ bodies resonant to the vibrations of sound. Mud, ," ;:Rqp: o.th Hence it must follow that a smoke ring- tog value, in SIIveli vortex-will ro- radio,. 245 push pullaudio, a most deucedly peculiar radioninsoles. kits.parts. d'. tate ninety degrees upon its axisif blown Guaranteed merchandise at wholesale Price& into tile path taken by a sound wave. WESTERN RADIO MFG. CO. pa. me LAKE ST CHICAGO ILL. Reflectors for Amateur NOW you can get the Movie Makers best new detective novels or only 25c at your near- (Continued front Page815) est newsstand. It's all the Wrestling Book result of a remarkable Learn at In a pinch the white -enamelled top can be newdevelopment in Home taken from the kitchen table and used as a publishing which enables FREEreflector. us to cut book -publishing costs to a few

B. S. DECREE Inexpensive Home -Movie IN 3 YEARS Sets By Don Bennett (Cannoned from page 806) big "drammers" and "spectacles."They have been the backbone of the motion pic- ..s greatest ture industry because of their universal itcl Master appeal.What should be more fitting than that the amateur club produce a Western, Says: especially when horses and open country are available.Overacting or underacting are not serious in a Western as everyone expects the villain to swagger around "COMPLETE equipmentwith Conninstru- and the hero to be stiff.P'ck your bestLearn ments enhances the musical value of any swaggerer for the "villin" and the stiff- band at least 50 %." Conne are the choice of the world's greatest artiste. est boy for the hero.Of course you must Especially recommended to beginners for quicker be diplomatic in picking the prettiest girl progress and greater musical success. Easiest to play. for the heroine, but she should have long Many exclusive features. Yet they cost no more., Electrical FREE TRIAL., Easy Payments blond curls to beatrue Hollywooden type. on any Conn. Write for interesting book. Tells everything you want to She needn't act.All she needs is to look know about your favorite instru- pretty and scared, by turns. ment. Full color illustrations of Engineering most popular models. Write today. With the boy's(small and grown-up) C. G. Conn. Ltd. 136 Conn Bldg. love for 0. Henry, why not pick on one Radio, Television, Talking Movies, Power, Elkhart, Ind. of his talcs for your Western. And don't i Aviation-all of these great industries de- be afraid to pick one with interiors.Have pend upon electrically trained men. you an old shed or barn that has an ell? Here in the School of Engineering of 'Milwau- 1014NWotan Gayest That's your western interior.Take a look kee,one of theforemost and best equipped elec- Manufartureacy trical schools in America we are training young BAND INSTRUMENTS at Figure 5.There is a typical barn with the last letter dropped as far as our movie men inthevarious branches of electricity, in a thorough, complete, practical manner.Jobs up to SEND FOR THIS FREE BOOK ON camera is concerned.It has been trans- $10,000.00 a yearare open to men of action nho YOUR FAVORITE INSTRUMENT formed into a western bar.The cowshed receive the highly specialized training given by becomes the back wall of the bar, bearing this 26 year old school. suchrepresentativemottoesas"Don't shoot the bartender." "In God we trust" Complete, Practical Electrical Education DRAWING COURSE $298and others of that day and time.The bar 1'. S. Gov't asks The biggest value you ever S. of E. to test is made of old lumber, the top painted with this huge electric saw advertised anywhere. yellow kalsominetorepresent a much - generating unit, Haven't you often wished that you -could timm built for Pan- cartoons, Illustrate some Idea, sketch some pretty scrubbed board.The sides car be stained ama Canal. face. ete.lb You can do all of these thing". One of Alnerica's must Nouns Cartoonists dark or covered with dark cri'pe paper. The andillustratorshasdevelopedagreat, window shotild be dirty with a few finger- simple system for succorsinall bombe: ofCkimmereialArt. Thissystem loos marks, as if it had been treated for trans- revolutionizedtheentiretheoryof parency on occasion.A round table in drawing.It meats that drawing CM! beaswowforyouaswriting - front of the bar with a kitchen chair or much simpler than looming Mort - hand,bookkeepingortymtwrititut. We are now placing this orliSted system for learning Drawing. Art and Cartoonlog.ent- misting of 34 lesions with over 500 illutor, Howe withinreachofeveryone. If will devote a few hours each week toth' Complete courses in Electrical Engineering-A.C. Course WE ABSOLUTELY CaTARANTLi & D. C. Armature Winding-Wiring & Testing- that you will learn to draw and draw w.! before you have halffinishedthe Grua.' Commercial Electrical Engineering-Radio Tech- If we fallto make this claim good we will nician-Automotive Electricity-Electrical Re- refund every cent paidus.By eliminating frigc, t large officeforcefor answering eortem md- ence, expensive catalog'.etc., we are enablod tt make a price of 52.95, the cheapest prh, EARN WHILE ever knownforahigh-grade home study course. Learn to draw.ItIs a big YOU LEARN meet, no matter what lir(id you are in. We help place students If you order the (ASIIrS, in part time jobs. Our Send No Money t once we will Ineluti. close cooperation with Just order the Course. and/talp drawing outfit several barge Milwaukee nnarrivalDay tiogrinan411 .4710 mistingofartist's industrial plants enables plus a few cents Tmlitage pencils, pens,paper, paymentInfullfortheentire "Western" saloon scene builtagainstan us to help ambitious stu (miler and Drawing Outfit. rimers, thumb tacks. ordinary barn. dents earn while learn- Be a "Registered" IfnotentirelyMt Wed.ret urn to ,enabling you to ins. Tuition, board and RainRadio Technician to within five days and we will workwithout room reasonable. 90 Days FUND MONEY. Address: tiny additional roost. Daily LedarerSehaeolaf Drawing ,Dept.2110G.0 hattaneega.reun broadcasting. School orchestra. Fraternities. Sta- two, a tall, small -necked bottle (borrow tion WISN is operated from this school. ()niers outside the U. S. A. payable $3.28 cash with order onefrom yourlocalmuseum because they're as extinct as the dodo), severalCLIP THE COUPON!State THE MIDGET SLIDEglasses, some poker chips, a pack of cards What Course Interests You RULE and a few water spots dress the table. Classes are now organizing. Don't delay. Get into Instantly adds, subtracts, mul- your chosen branch of electricity. Insure your fu- tiplies,divides.solvespropor- Sawdust spread over the dirt and smoothed ture in the great field of unlimited earnings and tion,givesallroute; and pow- outlevelbefore being tracked up with opportJnities. Send the coupon now! ers. Logarithms.Sines,Cos- ines. Tangents. Cotangents. etc. feet.The sawdust thin near the bar, a Also gives decimal equivalents, lettered and numbered drill and small ridge piled up about a toot and a SCHML rENGINEERING tap sizes. half away from it.An old hanging oil The Engine -divided scales are on whitennIehe3 aluminum and arc grease and water - lampissuspended from the ceiling(a Founded 1903 S.I. WI Milwaukee. Wis. Proof. Diameter 4'. Price with Instruction Book. stick nailed to the side of the barn above I Withmit obligating me in any way please mail free i $1.50. Pocket Carrying Case. .50e extra, ('ash or C.O.D. illustrated hook "Ili, ti. St Wee, i Through Elect rs- catalogue free.Your money back If you are not satisfied. camera range with a rope or chain sup- it y." andparticular-retest -ding the CutineIteasea GILSON SLIDE RULE COMPANY. Stuart. Florida porting the lamp. wailed with :tii X. I (SLIDE RULE MAKERS sINCE 1913) RESIDENT COURSES For "reverse angle" shots, that is, shots Electrical Engineering, B. S. Degree (3 Years). aI takenfromthe bar looking towards an im- Commercial Electrical Engineering. ( H. S. Grad- To -day for the uates 1 year: others 11: years). g aginary door we use the door further down Armature Winding. I "Electrical Worker's Friend" the barn, or even on the other side. Spread Light Motor Wiring and Testing. I Electrical Refrigeration. . Master Electrician. 1 [SendAnelectricalbookof 66motor some sawdust near it, thinning it out in a Radio Sales Service and Broadcasting. drawings with completeinstructions;AO Home Laboratory Service. V shape with the apex away from the door ( Home Study Course.) 11 forrewinding and reconnecting sill. ..I am interested In your "Earn You Learn" A. C. motors.Special at When shooting an exit or entrance, plan. ....Day ....Evening Cl Or Write for full particulars of this valuable give the effect that the door is opposite the Same Age book bar by having some one (the bartender) Address SMITH & SMITH PUBLISHING CO. look up when an entrance is due.Let i City Dept.It..V (!coria.l'a. your character walk on and later on slunot

a shot front square on to the door with theInEdneationIv ,c; Science and Invention January, 1930

(Continued frontpage857) character walking through the door towards the camera. Ship Models The same location, with a slightly different treatmentisused as the rustlers' With Electric$ Li 50 cabin. The barisrenb.ved, and inits place we have a bunk made of rough tim- Lights-only... II9 bers and holding a mattress stuffed with leaves. .\ few dark blankets rumpled up We furnish you with all the on the bunk and a wad of cloths for a parts cut perfect.No trouble to fit them together and in a very little time you will have a beautiful ship model that you will be proud to own, placed on your Raclin or mantle and lighted with the electrical equipment that comes with each model.They give the effect of a ship atsea sailing along on the WIN QUICK POPULARITY quest of adventure.We have the following models, all parts cut tofit and PLAY THE TENOR BANJO! ready to be put together, and a complete "T NETER multiligute%thyallthe iristurned toe andinstructionsheetnum- down until Jima Belli said to toe. you're a ithe diagram chap-but you're "dead." Why don'tyou"pep up" 1 bered so that you cannot go wrong. You'll bore gel anyttltele the tiny you ale now!' "Jim was right.lint what could Ito about It? Then Long Wide High I saw an ad-'My Banjo Matte Me Popular titer Nigio' Here was my big chance.Isent for details...and 19" w ell -- Flying Cloud 26V." 7/2" A"miner's kitchen" setting arranged 'In almost no time.It,C1.111,. 1003 (dole to play men SantaMaria 27 10 25 cheaply with the aid of an old barn. the most .11111eult look no- banjo to our nett Mayflower 30 10 26 party. (.10Ssleill (UM, jarz.'hutnumbers.' they CAW' as easyasrolling otT a log. Thatnight(forted La Pint's 27 12 26 towards popularityand has min me a 'whirr lob anti the 32 10 30 pillow complete the dressing of the corner. sweetest girl In the mi. lit."Do you want to lie popular Constitution to win (wick success and make money on the side?Tat, ( Pig. 6) A rough table with a cowboy's your first step by senility:today. now,tor details asto Every Model Guaranteed. candlestick (a liquor bottle with a candle hoe you ranlearntoplaythetenor banjo attonne- Money Back If You Want It. in the neck) and a few dirty dishes oc- es:Hy-4)1'1PR IsVi. We will send you any of the above models cupy the center of the stage. A chair or TENOR BANJO STUDIOS C. 0.1). anywhere inthe United States. two (different from the two in the saloon Dept. D-402 9th Floor Woolworth Bldg. Money order or check must accompany all set) an old wood -burning cookstove and a New York City foreign orders. pile of wood forit are against the wall. All model. shippedsante day as orderis A light piece of cloth over the window in- ructiV side the barn will serve for daytime shots, removing the cloth for "night" scenes.If MODEL WOODWORKING CO. the door happens to be located as shown ill the drawing, use it as the door of the Perkasie,Pa. . . Dept. C -I cabin.butnever showitopentothe - ' camera. When an entranceisrequired, place the camera where the opening door 4,644 i will cover any "outside" shots of the in- a rte. sideofthe barn, exceptfor the night scenes when this careis not necessary. _.1110.4 Drive a few nails around the walls and TypEWRITERhang some old clothes or riding gear on Ciherei. an air of them...... m...-iii..a,s, hospitality that youll hhe 4'.. .\ little ingenuity in following out these AT THE HOTEL iAPRICEI.It. -:-.-1114..,94 , suggestions, as far as local conditions will Now ,,.1.:71.ti.. - permit.issure toresultinlots offun ICC AD I LLY MI Standard Makes I-",:-:-/4,;1".,' both in making the films and in showing 227 WEST 454 ST to DROAOWAV .4:4::::,..r them.* cvIEWYOPKy ( Also Portables) 4 ' "..slit ' A ' Tear choke of tbs. World's best''' ADJACENT To CVERYAcnvine typewitere-Underwod.Rensing- Every organized club should have as a R0/10 - full else. tats model. raga 600 BRIGHT SUNUT ROOMS completely rebuilt and refinished brand ' it, . TRIAL clubprojecttheproductionofafilm. new. Prices below half. Sold on gees Terms. And as a word of caution, don't try com- -. EACH W iTN CLAIN, Just send your name CLECTOIC CAN,lCE WATER SEND NO MONEY!and address and we edies. They are the hardest ofallto win matt you our complete Free Catalan prepaid, fullydescribing SINGLE ROOM N.. BATH 4392 end showing actual photographs of eget, beautiful =seems infull make.Stick to drama and Nvesterns, they colors. Tells every detail of our dirselLo-roc small p-smentplan - DOUBLE POOMno OATH $4 Write now for tremendous wiring. No Mid/ration what, ereAnis/- are more in the amateurs' line and are lug issues -Act quirk. ,Yew (litre Supplies with eachTmiinsriler). ExceptionalRestaurant &Grille Easier to produce. Wag AT Oini Copcwscout RgagnianTIONS International Typewriter Exchange F.D.S0i I BUD ...... 0,twrree 231 W. Monroe St. Dept. 117 Chicago, Mine.* Contest Announcement TRANSFORMERS *(Editor's Note: If you have any dif- FOR RADIO POWER SUPPLY ficulty in applying these suggestions scud Power tor all receiters. Primary 105 to 115 cotta several photographs of your location front HOW TO O3TAIN 50orGO cycles Secondaries -2% various angles with an outline of what is A Better Looking Nose! volts. 9 amperes -2% volts.3 am- wanted. The Editor will gladly advise Improve your personalappearance peres -5 rolls center -tapped. 4 am- Itstwo Model '25 Nose shaper In you, in return for a photograph of the tic.ignedto improve the shape of peres -300 volts each side of center - dressedset,howbest toconvertthe the noseby remouldingthe car- tap, 125 milliamperes. All lugs tilage and ureic' Parts. safely, and "natural" into what you want.And in Tlikisaeconiplished mounted on bakellte, concealed in- give a copy of an Biro the very tine and precise ad- side rase, completely shielded. addition to that he justments which only my patented NIounting for sub -panel or regular, interesting one hundred foot, sixteen milli- Model 25 001,,e,. Itesults are lasting.ran be it at night, or Price 511.90.Write for our liters - meter library film to the club or individual during theclay. Money refunded tine.Ile:tiers getIn now. That scolds a photograph of the unique ap- ifnot satisfiedafter thirty days' trial. Write fortree bookletto JEFFRIES TRANSFORMER CO. plication of this article.All photographs M. TRILETY 7427 Alameda Blvd. Los Angeles, California must reach the Editorial Offices of ScIENcE NOM, \'.r. Shapinq Nprriariet AND INVENTION not later than midnight. Dept.74 Binghamton. N. Y. January 31,1930. The prize, or prizes will be azvarded as .coon after that date as ;a...line Engines, Steam Engines, Motors, Dyna-Motors. Lathes, possible.The right is reservedto publish eny photographs enteredinthecontest. CHALLENGE Drills,Gears. Books, Blueprints. ,./11.\!, itlol tale. le, no. Pulleys, Hangers. Bench Saws. ii 'rite name and address on hack of eachoar'snetsimplest. meth ii ran 10 101101t.0 eyle's'uof rt7enrt. Display Tables, Model Makers' photograph submitted.None will he re- chum.sneelbeael.err. Allfor 1.110. Praised byNets Materials and Supplies. turned unless postageisenclosed. The lurk.Boston.Montreal Police chiefs;colleges, Thurston; Blackstone,etc. Iffake,letthemarresttoe. Calais{ sealpostpaid20c, rebottled first artier fudges grill be the Editors of SciExcF. Axn HOWARD ENGINE & MFG. CO. INVENTION andtheirdecisionswillbe A. HONIGMAN, Dept. 35 2415 N. Ashland Are. CHICAGO. ILL. final.) Sta.E.P.0.B.fri Montreal. CAR January, 1930 Science and Invention 859 The Savings Bank--Li vin g Insurance He Left His 0asipitODU:1 VA itCE13"MAICBy Alfred M. Caddell, Financial Editor WE have been hearing alotlately Combined with Calling Card about stocks and bonds asinvest- 210 Power A onplitier and ments, but little attention has been "II"Supply Unit given by the pressto,\merica'soldest. -Telltale Finger Prints! standby-the savings bank. Last year approximately $40,000.000,000 .50 was on deposit in the savings banks of the nation, earning from 3% per cent com- This (annuls genuine Bolster pounded monthly to 5 per cent if left over K-5. AC Electro-Dynemic Re- producer Is complete with a 210 a period of time, and with little or no Power Amplifier and "B" Sup- risktoinvestors. True,thesesaving - Height 42" oly.Intlallself-containedon Width 25. a" steelframe. Thisrealfine banks reinvest their depositors' accumula- Depth 19" matched rugged Unit weighs 45 tionsinstandsecurities,such asfirst lbs.o [Moutthe Cabinet. The Cabinetitselfis Pend I -Striped mortgages tin business and home proper- Walnut. beautifully designed ties, government bonds and the like.In tr ith Cathedral grille. If fleshed. the 210 Power Am- a sense, therefore, the savings bank is the plifier still also supply 22, 67 and 90 volts "B" current, first real investment trust, and the deposi- sufficient for any set using up to S tubes.An automatic voltage regulator tube, UX-874, maintains the "B" volt- tor'spass -bookishisshare of stock- age silent and steady. good for itsface value plus accrued in- This Eleetro-Dynande Reproducer ran Ise used with any terest or dividends. battery or Al' set, replacing the last audio stage, or be used o ithalltubes of the set.Wherever used itwill In bygone days, the long lines of de- lit ins out every shading and range of tone: every note is leittodtteed tutuutmost Wadable,. pure alitl undistorted. positors at the savings banks on Satur- ItoIll modernise any radio receiver. day nights constituted one of the outstand- Ises 1-1'X-210. 2-1'X-281 and 1-I'X-S74 tubes. ingfeaturesoftheinvestmentworld. A 20 -ft. table Is liwitified with each instrument.Oper- ates direct from 50 -Oil eyele, 110-120 volt AC current. Owing the bank for one's own personal ac- Brand new Inoriginal factoryrases and guaranteed. count was a wonderful form of debt to get Ever Reproducer I, serial -numbered and ha: factory guar- into. But, nowadays, the long lines are giving way to Uncle Sam's mail -carriers. Three bloody finger prints on the cash regis- AMER ICAN SALES COMPANY Deposits by mail constitute a large and ter! He might as well have left his calling 19-21 Warren St. New York Cityever-increasing way of paying the bank card-his doom was already written! These silent witnesses told the story- identified him something for yourself. -convicted him!Mail coupon below and get Progressive savings banks all over the this gripping story FREE, with 12 others just 30 country have goneinforsae-by-mail as exciting! rSvFDIAYSgnA0 RA D 10 campaigns. TheFranklinSocietyfor -10Months to Pay Home -Building and Savings, in New York 13 True Detective SAVE $25 to $100 City,is an outstanding example of save - All Electric With by -mail institution.Their advertisements Dynamic Speaker have brought them depositors from all over StoriesFREE SersainGrid ***** the country, not that they of The Ranger &al becoming Gripping Mysteries!Gruesome Tragedies! the most favorably known radio- taking customers from other banks, but Daring Deeds! Hair -Raising Climaxes! Every now leading the field. es it% pre- rather to interest the man or woman, boy story will thrill you-grip you! fordecewor. 30years-grid-tirid the Ranger Bicycle, Tube has RangairNentrenlyn twitb 9 When) or girl, who otherwise would fritter away Think of it!Real Secret Service Operators fith 2 No. 245 Tubes in"Push-Poll.. give you "inside dope" on real crime cases made under patents of R. C. A. hishard-earnedcash intomeaningless assures you and how they won handsome rewards! These reception from ne 41sta.distanttive nothings.The Emigrant Industrial Sav- stories are YOURS FREE!-if you act quick! dons.You may nowown one ,.f thew itinctive Rangers with Dynamie ings Batik, another New York City insti- Mail the coupon NOW! OpeakerinaDeLuse Cons.de itypuy tog IAA low NA $10.0 down and bid- tution, reputed to be the largest savings srice in 10 months. Table models is., ow as $40.0U. Rangers came all bank in America,isanotherinstitution ready to liiii-tOmply insert tube. Liberal ut..1 plug into your elictric light Discount Where which has added the names of many de- t ..k et -no more tr.olible i ban tucon- We Rave No r., an electric floor lamp. Eactusive Dealer' positors to its hooks through the facilities '2500 '10,000Year MeadWelfare, catalog and ma rvel o us new Introductory of ter-easy terms offered by Uccle Sam.Also the National CycletCo., DepLZ-173,aimless. City Bank (New York 1,which has in- Finger Print Experts solved every one of augurated a statement plats as a means of these weird, blood -curdling crimes!Finger reminding depositorsthatthey owe the Print Experts gathered in the great big re- DEAFNESS IS MISERY wards! Every day more and more trained Multitudes of persons with deity tie Luring hanksomething, forthemselves every men are needed. New Bureaus of Identifica- and Head Noises entity conversation, nsonth. They mail out a statement about tion, new positions are opening up all the go to Theatre and Church because they the 25th of every month, notiiying deposi- time. The field is uncrowded! Opportunities Use! efmard Invisible Ear Drums which tors that another payment to their own are unlimited! resemble Tiny Megaphones fitting in thef. at entirely out of sight account isdtti2. This statement serves as No wires, batteries or head piece a depositslip and umin receiptthe de- They are I nonpon,i,e. Write for The Knock of booklet and sworn statement of p)sitorsimplyfills intheamounthe the inventor who was himself deaf. wishes to deposit, enclosesitwith his re- A. 0. LEONARD, Inc., Smite 615,70 5th Ave., New 'fort mittanceinanenvelopeand sendsit Opportunity merrily on its way. Is the knock of the postman an he bring, thin book, So that no error in Prints," to you.It brings you fascinating JENKINS $ sddress shall take place, these banks pro- true detective stories-lt fellis you how YOU can be- 97 come a Finger Print Expert quickly and easily. Write tk=t=I -4.IxWatch -Lighter vide self-addressed envelopes. for FREE copy of confidential report operator No. coacifilieed 6,1enel watch and new design 38 made to His Chief. elegant cigarette lighter in one. Watch in A large number of savings banks now of excellent Swiss make, tested and ad- payinterestonsavingsfromthe day justed. Two years' written guarantee. YOU ran learn Finger Print Identification easily, In Radium dial-tells time in dark. Lighter received to the day of withdrawal. Modern a short timein your opero time --at hornet YOU can is of sturdy cornitruction and can be opened business equipment. interest tables and the snake MOO to;10,ttitila year as a Finger Print with one hand. time, instant flame.Largfluid Expert,Find out how you can enter this most CillileitY.Easily replaceableflints. Zlee irant like make itpossible for receiving tellers thnllicg, adventureaome profession and make covered ease. SENT, NO MONICY. Pay on big money fast! SI.n7 postug,,tetisfactIon to make an entry, post the hank's ledger te...1, JENKINS, 681Broadway, Mew York.Dept. 65 -A 1 . and bring an account up-to-the-minute all InstituteofAppliedScience in one operation.This makes itpossible 1920 Stuutyolde Ave ,Dept14.21Chicago,Ill. to effect short-cuts in bookkeeping, guar- RADIO BARGAINS! antee precision and speed and for one man Bland Less 7 tulle t' . guaranteed $29.75 to handle thousands of accounts in one ..MailTnisNaleforFreeBookIMO Short Wave 1tube s.. 4.75 day. Institute of Applied Science, Dept.14-21 Used 5 luteI ns .1. 9.90 1920 Sunnyside Ave., Chicago, M. Power Transformers and Conden,r Slink+atrat rem,' I As an example of growth in the use of Without any obltsiation whatever, send me your mew lineprices. S. nilforhit litof.stew-orlr- the save -by -mail plan, the mailing depart - fully illustrated, FREE book of authentic detective an.1 1"."3. CHAS. HOODWIN CO. men of The FranklinSOcietyhandled tales, "Finger Prints"; also foil particulars about 4240 Lincoln Ave. Dept. A-3, Chicago your Low Prices and Easy Ierms. DEALERS IN BANKRUPT RADIO STOCKS 100.151pieces of incoming mailinthe twelve months ending June 30, 1927. The Name be sure of getting your copy each month, following twelve months showed anin- subscribe to Science and Ins ention, $1.50 a year. crease to 128,171, while its the last twelve Address EXPERIMENTER PLAWICATIONS, months ending June30.1929thetotal 351 Fourth As enue, New York City. (Con!inuedon page861) City and ::tae Are Science and Invention January, 1930 Shoal Waters WhereinYoung Channing Meets the Toughest Trio North of Rio Old Pawlins A Desperate Gang of Bootleggers Dare Everything to Run Uncle Sam's New Coast Guard Blockade

THE beam of the searchlight movedglasses.While he had been enemy tries to pull a in a wide circle as Ensign Channingthinking of Hogan these en- fast one; "Four - followed its course with his binocu-listed men had located the footed Fury," where- lars.The Coast Guard cutter was run-boat with their naked eyes. ina famed Spanish ning parallelto the shore and severalHe removed his glasses and matador is outdone miles out. They had run south from Capefigured rapidly. by an American cow- Fear River to Snake River Inlet and were "They'reheading for boy in a thrilling duel heading back to the station. Dead Man's Inlet." Flem- of the hull -ring; "The Old Pawlins was standing beside theing cried, waiting nervously Ace of Death," a fiery ensign. for commands. tale of South Ameri- "The sea is running high tonight. Good Dead Man'sInletwas can intrigue, with a night for the rum runners to try to makeone of the numerous inden- fabulousgoldmine a landing," he said. tures which dotted the Caro- as the winner's stake; linacoast.The water at "There's Gold Across its the Seas," an unusual its mouth was jammed with tale of an old news- "His gun, islands. Several narrow, paper reporter who thank God, winding creeks flowed out sets out to obtain the wasstill ofitthroughtheheavy strange fortune willed dry" brush of the swamp.Once Channing to him by his former lost in that inlet, the rum major inFrance; boat would be safe. "Red Diamonds," in "Stand by to fire," Channing ordered.whichan Africanmissionarystumbles So begins but one of the greatrip-upon King Solomon's fabulous wealth and roaring stories of he-man adventure to hethe fight of his life: and "Flying Gold," found inthe NEW BRIEF STORIESinvolving a thrilling tight in the air for a for January. Getacopy today fromfortune. your nearest news-stand and follow Chan- They areallinthe NEW BRIEF ning and his shipmates through the mostSTORIES for January. now on sale at bewildering experiences ever to happen toall news-stands for only 25c.Get a copy a Coast Guard crew. today, and settle down to an evening's "Shoal Waters" is only one of a dozenreal reading pleasure.(Adv.) greatadventureetorieswhichappear Bart Charming nodded.He could feelevery month inthefascinating NEW the boat riding the huge swells as heBRIEF STORIES.Read "SOS'edto watched the white caps, iridescent in theVictory."a story of the stream of light. Great War inwhich the "He shoved "It was on a night like this that Lieu- her hard tenant Hogan made hiscapture."said sport, and in Fleming. asplitsec- Always LieutenantHogan. Channing - wasand the half hoot thought.He heard of nothing but that __c_ capture since he joined the Coast Guard filledssi t _ water" Station.Hogan himself seemed to feel superior because he was an Annapolis graduate, and more than once he had spoken inslighting terms of the Coast Guard Academy from which Bart Chan- ning had recently been graduated. "Look! To the starboard!" shouted Carey from his position beside the electrician on top the small cabin. "She's a rum runner. and one of them fast ones," Paw!ins exclaimed, looking at Ensign Channing Channing cursed himself as he picked the speedin' rum boat up through his January, 1930 Science and Invention 861 MAKE (Continued front page 859) numberofdepositsbymail numbered 142,224. GOOD RECEPTION Saving by mailisvery easy.If you have no accountN\ ltilthe bank of your --"NEAS1( choice, simply send your first payment, and your passbook will be sent you by return Thousands ofmail, together with a card for you to sign users marvelattins difference in recep- for purposes ofsignatureidentification. tion with a Towns- To make further payments.it end "B" Power is merely Unit.Full, sweetnecessary to enclose your check or money tone, clarity, vol-order, or if currency issent be sure to ume and greaterregister the letter.The pass -book should. distance arc among the many advan-of course, accompany each remittance. tages reported daily. Withdrawals are just as simple. You send your passbook to the hank with a The only man who TOWNSEND withdrawalvoucher,or aletter,ifno )54/Q C "II"POW=vim voucher or form is at hand.The bank's could talk to Hooked up in a few minutes; check, which is charged against your ac- just plug into the lightsocket the Superintendent andforget it. Delivers up to 100count, goes back to you the same day your volts on any set-D.C. or A.C.-withdrawal request is received. "Soot.; after I began studying." a student wrote to us auy cycle. the other day, "we had a change in management at Such a simple way of creating Living our plant.I certainly was glad then that I had de- CC M Approved and passed by lb*Insurance-the kindwhichhasproven cided to study in my spare time.For, thanks to my rigidlaboratorytest s of riiprh.very handy in countless instances-is cer- I. C. S. course, I was the only man in the organiza- tar Rudi.,- olia"1111.1i11 s. tion who could talk to the Superintendent in his own Over 150,000 Now in Use! tainly \veilworth trying and adopting..\ language. As a result, I was promoted over men who There's no longer tiny few dollars at hand are often worth more had been here from ten to twenty years. My salary immure' for putting up with than all the prospective dollars which may has been increased 90 per cent in the last ten months.' the expense and undepend- be tied up in other forms of investments. able performance of "B" That's atrue storyof what just one I. C. S. studentbee Batteries -when you can Brats 135 done.There are thousands of others.Every mail Wings own a good"B" Power rnit Volts of "B" letters from men and women telling of promotions andin- for$6.85.Over 150.000 Batteries creasesin salary due directly to spare -time study. Townsend"B" Power Units YourEliminator Questions and Answers One hour aday. spent with the I. C.S.in thequietof now in WCP-(11 substantial iseery satisfactory. Conducted by Alfred M. Caddell your owu borne. willprepareyou for111MenIn the hock ',roof of satisfaction. Ihadbeen wine you like best.Yes, it rill!Put It up to us to proseit. three 46 -colt "B" Financial Editor Mail this Coupon for Free Booklet Send Only $1.00 batterieswithrim tot. Ind I yet better Ouestion-What is the outlook for Radio Cor- =Maim...mg Send name and address resultsfromyour porationofAmerica? I owntenshares with only $1.00. On arrival h0-roltEliminator 'oughtat80. E.I.. B., Ridgewood. N. J. IN fERNATIONAL CORRESPONDENCE SCHOOLS of Townsend Power Unit than I Pot from the Answer -For the long pull thereishardly "The Unierrait .1 tty" pay postman $5.85 plus 1.15rolls of "8" any question but what Radio Corporation will Box 6206-F, Scranton, Penna. postage. Try out ten days, batter ire. prove to be a good investment.This corpora iTihntitcostor obligationon my part. please sentme then,ifitfails to do Joseph Mallen. pion is the holder of basic radio patents which a eonw of your 48 -page booklet, "Who Wins and Why," everythingwe say, return Pr -06(1(11m R. I. are used largely by other manufacturers. It andtell me how I can qualify for the position, or in the it and money paid us will isalso affiliated wills other promising enter subject, Wore which I Inane marked an X: TECHNICAL AND INDUSTRIAL COURSES be refunded. Make a prises in the amusement world, as well as be- Are'litect I Automobile work BEALreceiver of your set. "4.v. ,""` ing one of the world's leaders inradio -tele-8ArenitecturalDraftsman LI Allation Engines TOWNSEND LABORATORIES graph communication.Long pull ac emulation has BUI1,11111:Foreman lumber and steamFitter been proceeding in Radio in the belief that the Cons.rete Builder Li Plumbinginsi.etur 725 Townsend St. Chicago, Ill. stock has inviting potentialities Over the next few jeorCrartorand Builder[J Foreman Plumber ListlueturalDraftsman 0 Beating and A'enillotion years, but the recent high prices have discounted UStructural Engineer LI Sheet -Metal Worker the future several years. Electrical Engineer CI steam Engineer Question -I am a business woman with two Elodrieal l'entractur Marine Engineer WANTED MEN children to support.llave $5,750 in the say Electric Wiring la Refrigeration Engineer To Manufacture Metal Toys and Novelties lugs hank which I would like to invest. What Elect rie Lighting Pi It. N. Positions nig nd Electric CarRunning C.1Highway Engineer tor 3 and 10e store do you suggest?Mrs. C. R. It,, lima, Ohio. Telegraph Engineer Chemistry Nincil it, .111t rays. Toy Soldiers, Answer -Ii you now have a steady income. Telephone Nl'ork Animal-, AutoRadiatorINna- Illelit . I would suggest investing $5.000 ju good stocks Mechanical Engineer P0iP'ohour MiningnmeEngineer ele. WC ... opera t eIn and bonds,leaving $750 Merttanlenl Draftsman LI Navigation 0 Assayer telling totals you make; also buy for emergency pur- Machine these lions you.Small insestment poses.For your purposes, ten shares of Utah shop Wattles UIron and Steel Worker needed to Toolmaker Textile Overseer or Supt. start andWehelp you Power & Light $7 preferred stock, ten shares Patternmaiser Cotton Manufacturing build up. WE FURNISH COM- American Water Works & Electricfirst pre Civil Engineer 1 WoolenManufacturing Phrri: OUTFITS and start you furred, ten American BrownBoveripreferred. Surveying andMappingElAgrieulture 0 Fruit Grovel/11 in9 ell-PaYingbusiness. Abs.). American Steel and Foundry preferred. Pacific IBridge Engineer I Poultry Farming hurls. Nat EXPERit:NCEandon LJUas Engine OperatingU Mathematics 0 Itadio nr \ .1. -111.1101 111, net/led. l'il:11111. ora To. & Tel.preferred, or anymultiple that Met ilne for lolls with small capital. you may desire.This will provide diversitica BUSINESS TRAINING COURSES Wri:e AT ONCE if .0ow:di strictly1,11Ine*:old tion with safety and yield you 7 per renton 0BusinessManagement 0 Business Correspondent* o ant to laaalle 1.431, ,1,..a...ile mil.,110. 1.1.i111:Plared ytrurcapital. For bonds, New York Title & fJlinti.strlal Management U showCard and Sign METAL CAST PRODUCTS COMPANY Mortgage, $:.000 Lawyers Mortgage,5'Is 0 Personnel Management Lettering DEPT. E 1696 Boston Road New York City 0Tralhe Management [j stenography and TYnitilt S. W. Straus first mortgage 6s and National Accounting and C. P.A. ElEnglish Mortgage 5! -isoffer gooddiversificationwith Coaching DPhil Service nominal income. Elenst Areonliting U Railway Mail Clerk nuestion-I have been offered 100 shares of Bookkee dog IA Mall Carrier ORRECT Ford Motor, 1.1d.. at 20.1)o you consider this 1j:seen-tar al work flttrade School Subjects a good buy?P. 1.. A., Houston, Texas. Ugmnigh n French fillighSelmolsohiect, Your NOSE Answer -Ford Motor, I.td., an English com- USslesnianship II Illustrating0 Cartooning pany, offers a good speculation. LJAdvertising U Lumber Dealer appearancewith The company A : I'1' A Nose isan cs.trnsionof the Ford Motor Co. and NAM! Adjuster.should become a dividend -earner.But why 'I rent Shapesfleshandcartilage -pay 20 fcr this stock when it can lie purchased Add, a (hi 'sly,safely andpainlessly, nile in the open market for less?Stock recently yousleep. Resultsaresoldas low as10!x and atthiswritingis City State laing.Doctors praise it.68,00 about 14. users.Vritefor30 -Day Trial Information on securitieswill be furnished Oct tip..tion Offerand FREE BOOKLETreaders yon residein Canada,send this coupon to the ANITA INSTITUTE. 171 Anita of "Science and Invention" freeof Internstionat Correspondence 8. hootsCanadian, Limited, Bldg..Newark.N. _J. chargeby mail and throughthesecolumns. Montreal. Canada A 2 -centstamped,selfaddressedenvelope 111 should be Includedin your letter.Address The Financial Editor, Science and Invention, WHY NOT spendspring, ?hisBOOKIOf Fourth Ave., New York City. Summer,Fall Amazeand MystotYourFriends! gathering butterflies, insects. Earn at toolParties. I buy hundreds of kinds for No 1 i n,1 1.1 '1 "The collection. Some worth $1 to IMPORTANT $7.Simplework with my Instructions, pictures,pricelist. Send10c cataitg. Sci,11V..Ludo. (NOT IJtzWOHDLRS TO NEWSSTAND READERS STAMPS)formyProspectus before send- Wiesen LYLE DOUGLAS TN order to eliminate all waste and unsold ing butterflies.Mr.Sinclair, Dealer In In- Station A-3 Dallas.Texas opies it has become necessary to supply sects, Dept. 41, Box 1424, San Diego, Cal. .s -nand dealers with the actual number of owes for which they have orders. This makes itadvisable to place an order with WADE BENCH LATHE Learn your newidealer, asking him to reserve a Cap: 4" dia. x 12" length. copy for you every month. Slidet esthastravelen - Otherwise he )1..- tirelengthoflied. will not be able to supply your copy.The 4 Lead -serest indde bed. dealer will then be in a position to sup- ltullow spindle. Turn- Make m110tOgaterv3IEtaking pictures. P ulckly during spare time. Also earn while you learn. No fence ply copies to you regularly every month. ing.facing,boring. necessary. New easy method. Nothing else like it. If you are interested in ing your copy wlnJing. thr,o1- Send at once for free book,Opportunities an Modern every month, do notfailto do this.It ,11,1n.....No. I Lathe. plain headstock $40.00. Ns. 2 Lathe Photography,and full particulars. costs you nothing to do so. back -geared headstock $68.00. Either lathe. 4.'3E18" 00 AMERICAN SCHOOL OFPHOTOGRAPHY estla.l'.aophde line ofaeceNorieiat ...nosilylase prices. Dept. 1,21. 3601 AlsthIgan Ave. (.Menge, U. S. h Ca,a1..4snittroy. THE GEROLD COMPANY Dept. S-24 120 Liberty Street New York 862 Science and Invention January, 1930

Read Classified Advertising It Pays ! I Advertisements in this section fifteen cents a word for each insertion.Name and address must be included at this rate.Cashshutiii... accompany all advertisements unless placed by an accredited advertising agency.Not less than 10 words accepted.Objectionable or misleading advertisements not accepted.Advertisements for these columns should reach us not later than 1st of 2nd month preceding issue. Classified Advertising Manager -Experimenter Publications, Inc., 381 Fourth Avenue, New York City

We make necking models forinventors .4 dvertising Airplanes -.-1 viation For Inventors and do experimental work andtarrya i Isle filele 1,111Ckofbrass gears and model Get into Advertising. Learn quicklyat Biggest. Best Catalog Model Airplanes. Inventors, useourspecialservicefor supplie-. Semi for catalog. ThePierre home. Experience unnecessary.New, easy Parts, Supplies; 5e postpaid. Ideal Com- presentingyourInventionsorpatentto Model Works, Tinley Park, Ill. No text -barks used. Practieal work. pany, 23 West IStli Street, Neu York. manufacturers. AdamFisherSlfg.Co plan. 2.1 A Enright. St. Louis, 510. Old established school.Send name and ad Wanted -anopportunitytoback en- dress for intereding free booklet. Page SIMPLEX AIR MODEL CO.. Auburn. gineer;551111 IICWidea,for the improve- Davis School of Advertising. Dept. 533-A. Nlaaa, Model Airplane supplies.ga:,en- FREE BOOKLET ON PATENTING New Sterling Buck, S-1.29- F. Wash- ment of airplanes.If we feel you Poen- 3601 Michigan, Chicago. gines.s. intsections.gliders. hooks on inveution.. t are practiealwrsi ill helpyou tootle'building.gliderconstructionand ington,D. C. iieselopthem. AlexanderA irritatt aerodynamics. Send 5e for catalogue. Dept.15, Colorado Spring., Colo. Agents W anted Blanking and firming dies. Light stamp - Propellers4ft..$6.00; 5ft..$10.00: Machinework. B.L. Nortised. Stiteliell,So. Dakota. Gigantic Mail;send me 25e(coinor iirt..014.001; Propeller. for stem and ice sump.. forone pmts.! of mall. Strange newelectricironcard' P is sled,. boats. road speedsters, canoes. hydro- Ted Cannot kink Armour. 1 5.; East 35th St..N411 'V k. scorching. Sakes electricity. planes and airplanes. Specialpropellers Unpatented Ideas Can Be Sold. I tell or snarl. Used on telephonesalso. $25 builtto order for all types of craft.We 3111 how and help you make the sale.Free Samples FREE. Neverktiot, Dept. daily. carry the largest stock of small propellers Partirulars. (Copyrighted 1 Write W. T. 1-K. 4503 Ravenswood, Chicago. inthel'nitedStates. Twenty yearsof (;reeve,9518 Barrister Ilidg.,Washington, Music and Musical Instruments propellerbuildingplusmassproduction D. C. Amt. -New Patented. Automatic Von means better propellers for less money. We SONGWRITERS: Submit yoursong - tintingSafetyWindou Lockthatbaf- ship the same day. Writefor ourfree Inventions Commercialized.Patented er poem or romplete song.Quid: des Lion en flesburglars. Endorsed leypolice.Insur- prim. list.The Crawford Motor and Air. untosented Witte. Adam Fisher 311g. Co., 2'42i12bIlityforpulfilrat Ion -unaiseptablc ance men eveweliere. $15 to$23 daily glance Manufactory incorporateel. Seal 205 Enright, St. Louis, 51o. manuscript returned. ChesterE.Escher, easy. No eonefeetition. Nothing else like Begat.r'alifornia )twitPutili-lier.121 W. 17thSt., Niw it on mulls.Sells in homes, banksstore: Formulas. processes; all lines. Individ- York l'ity. garages. every place there are ulnelows. Business Opportunities ual Service.Moderate charges.ltx ('lore, minute demohstration.3 to 12 needed In Industrial Chemist. Crawfordsville. Ind. SONGWRITERS! Melodyfor words every house. Elinuorei Mfg. Company. 1001 one dollar. Frank Litlig. .Nloonin. Cali- Elmwood Place, Cincinnati. Ohio. Unusual tunities in the Neon Tube fornia. RiauBuines! Newindustry. Help Wanted -Instruction Reliable. authentic Make, Sellyourawn profits. Big salaries. Be Independent. information. $1.110. Neon Laboratories. goods. Immense profit:.Catalog depend- Work for "Uncle Sam." Life Jobs.eSteady Old Money Wanted able formulas, special selected agent.' best Box 203, Houston. Texas. work. $101-$200month. Sten-Women. 4211 Cottage 1,11-50. 'Thousands 1930 appointments. sellers FREE. E.Ludro, order $500 EACH paid for Old or Odd Grove, Chicago. FreeBook. Startlittlemail Many examinations coming.Common edu- $5 to business. Hash, II. 53-74 Cortlandt Street. cationusuallysufficient. Experience un- Coins. Keepalloldmimes. many 5,5 New York. necessary. 1.1stpositionsandfullpar- valuable.(letposted. Send to sent-for FreeBookletdescribes67Plansfor ticulars - Write today sure. Ulu:Crated Coin Value Book, 4 x is.Guar- making $20-01110 weekly in home, or on, Amazing Patented New Tool Specialty! Franklininstitute,Dept.El,Rewhester. anteed Price, Coin Exchange. Room 1O, Business ofyour own.Elite Co.,84-11. Faelories. Cilrages, workers buy on sight! Le Roy. N Elizabeth St., N. Y. Preffit75e. No competition!Treniendoui demand! Exclusiveterritory. Merchan- Be aDetective -Biggest paying work; B ig money and fast sales.Every owner diseinvestment required. FREE trial everywhere.Write National Headquarters, Patents buys gold Initials for his auto.You charge offs r. 31111enco, 1307WinthropBldg., 109 East 83rd. New York. 01.50; make 81 35 Ten orders daily easy. Boston. Inventions Cemniercialized.Patented er Writeforparticular:andfreesamples Wanted Immediately.Men -Women. I8- impatiaited Writ, Adam Ft hr rMfg. American Monogram Co.,Dept.71. East Amateur Cartoonists: SellYour Car- 74. ellialify for permanent Government Posi- Co.,911 Erwishi.St.1,oti., Mo. I range. N. toonsNew 1.1311. S111 Ith's Sen ire,Es. tions. $105i$250 month; experience notre- 1194. Wenatchee, Wash. quired; Vacation a Rh pay; common esluesi- 500 Formulas and Big Illustrated Cata- t ion; many needed soon.Write, Instruction Patent Attorneys log 25c.Ideal Book Shop. Park Ridge, Ill. Novelties.Bar- Bureau. 293, St. Louis, quIckis. gains! LargeCrosits! l'artieularFree I.-Etter,. 525 South Ilearhorti, a birago. Railway Postal Clerks. $158-$225 month. Patents Procured: Trade -MarksRee- Import Time Own Goods. German export Steady. Spring examinations likely. ntered -Preliminary oils i,s' fund 'bed w msgazine publi.liedin English. offers outcharge. Booklet and formfordi.- B IG MONEY AWAITS YOU HERE. CO11110011 education, Slen 10-35. 25 numerousbargain..latestnovelties;op- awl pictures an hour ssithout Write immediately.Frank choing idesfree. Irving I.3111'atliran. portunity for obtaining profitable agencies; no Signs 1020101 free. it.;Intern 'Ilona'Blinding.Washington, ormachinery. Samples and . V, press,type lin Institute. Dept. E13. Itirlsenrr. N copy60e. Square DealSupply. 210 particulars]tor. Soar.,1015Mulberry, D. C. Fifth Ave., Ness York. Springfield, Ohio. How to Entertain Inventions patented: confidential advice: Succeed With Your Own Products.Make invention, developed -represent at ire f. r them yourself. Formula:. Processes. Trade - Camera and Photo Supplies Blair Tool and Machine Corp.; trade -marks Ploys. Musical comediesand resist's, Kiiivarsi Gottlieb. Patent At- Secrets. .%1I lines. Catalog.51re ular. minstrels, comedy and tall registered. free. D. Thusly Co., Washington, D. C. in Learn torney.5 Beekman Street, New Yolk. Make money Photography. faceskit.VaUdil I Ileart quiekly athome. So.sre or full time. New logs.recitation.enteria , sues sic Make your own products. Employ agents Plan.Nothing like it. Experience imnerie.- plays and songs. musical readings. make- JAPAN; Yoshijiro Nakane.Registered souraelf..Toilet articles. soap. extracts. Me sary. .1ineriiianSchoolofPhotography, up goods.Catalog free.T. S. Denison & Patent .Attorney, 21. . furnisheverything. Valuable lankFree. Dept. 5332. 3 # # I Mishigan .An.. co. 1.3::So. Wabash, Dept. 99, Chicago. Teimijiku. il.ak.i. National Scientific Laboratories. 1932W W. Broad, Richmond. Va. Patent Sense. As one of the oldest firms Chalk Talks Insects Wanted In.knierica se goerimt tato,.at 100 c.1 service noted forre- $60-$200 a week. Genuine Gold Letters runs) den! char,. a Free Laugh-Produeing P m. $1.00 Catalog Cosh paid forbutterflies.Insects. See sult.. eviii-nresi by many well-known for store 'sleekest, Easily applied. patent, of value. Boo... Liberal sittertogeneralagents. Inc. Bahia Art Service. Dept. 4, Oslik.)11. Sineheer'sAtilCrtiSe211.11t 1.1. page Sill. ektraordinary samples. Wis. Patent -ea,. free.Larry & Lacey,644 Metallic Letter Co .441II..Noll!' ''lark. Estals !costs Chicago. I" Street, M'sibin.rion. D. Chemistry Inventions Wanted $10 daily silvering mi plating and Patents. TimecountsInapplying for riitinIshinglamp-.reflectors,autos,bests. Inventions Commercialized.Patented or patents. Don'tri.k delayinpretesting chanilellers by new meth..1. ilutlittar- Chemical Experimenters -ISOdifferent impateuted Write. Warn 1111Cr Slfg. your ides..Sind sket. Is or model forin- ofII ighed Quality. Sunicient nished. Write I:unmet:it Co Ave.Is. Di- cheinieals .1557. Enright. St. Louis. 51o. stals tions orwrite for Free book. "How to quantitiesfir hod of experiments. Appa- atur.111. included. Obtain a Patent- awl "Reeord of Ins, - ratusto performexperienced Inventions Wanted -patented. unpatented. Price $5.00. 50 pieces of High Grade .Ap- If you lime an idea for sale write. Mart- lion" form.No chars', for information on Are You Tired if working long hours for paratus. peke $7.00.Lslerrai,1 ItsIllIgh i,. Box 920, Bangor, Maine. how to proceed. l'ornnuitilcatIonssubtly small pay?lie your 0011 bo-! 1'1/ show School. l'ollege Students and Home Labo- confidential. Prompt, careful. efficient yriu how to make $15 profita day.Easy ratories. Send Money Order for your out- Clare.... A. O'Brien. Register,' work. No capitalneeded.Albert Mills, fits now to Pine Chemical Co_lr,2(Sr. service. 4996 'lonmouth. C inci heat I. 0. Marks Ave., BreeeklYn, N. Y. Machinery and Tools PatentAttorney. Security Bank Building (directly arras street from patent office,. ConcreteBuildingBlock Machines and W.,10141.ot.1/ C. Seepage 893. You Are Wanted to resilver mi at Your Chemical problems sashed and work- Concrete Alarhine furFiveDollars. Catalogue tree. home. Immense profitsplatingantopart s, ingprove.:fs oil shed Louis,Ito. tableware. rte.Write Sprinkle, Plater, 955. Write me. W. StedmanItleharri.Con- Co.. 5 First St.. St. "Inventors' Guide" free on request: gives Marion. Indiana. sulting Choi. I I .Box 2402. Boston. Mass. valuable Information and advice for all who Igoe original Ideas or improsements. Frank Magic and Games RegisteredAttorney and En- B igMarley applyingGeldInitialsen Lederman. Automobiles.Easiest thing today.No ex- Correspondence Courses gineer. 213 Broadway, Niw York Illy. $1.45 profit every $1.501 Magic Catalog 20e Lynn's. 105 Beach perience needed. Dept. 6.Jersey City. N..1. boom Flee Sample "Rahn." 111043 Wash- Used denseschool coursessold Patents --WriteforFree Instructions. ington. Boston. %lass. 0,i 111,111-111a ita...14 Also rented and es- 'tend drawing or Models for Examination. fluurzed Money -look guarantee. r ',tabor CarlMiller,Registered PatentAttririsey Male Help Wanted thinner Patent office examiner(. 238 Mc- Letters and Script I ree. (Cour,. bought). Lee NI...twain. GoldLeaf Window Pisgah.%Loots, CIII Washington, D. C. stens; no expel jence; Soar} profit; <221111C; Firemen. Brakemen. Be men (white tree. Consolidated. 09-11. West Van Buren, Cis r 'I'ra inPorters hicatto or tailored).Sleeping "Inventor's Adviser." Valuable Patent - Detective leribire.11,$17.0 $2i) monthly. Fittserienee hook sentfree. Labia,. 15Park untie...5,4:4re. $97 Railway Bureau.East New York. Men Wanted -To demonstrate and take Detectives.Work home or travel. Ex- St.Louis. 111. ordersdirect f motorists. .Amazing unnecessary. Parthiulars free. Unpatented Ideas Can Be Sold. Itell Statuette Trouble Light. Sticks on metal- nerienee Manufacturer wants distributer for 300 - WriteGeorgeWagner.2190Broadway. "Sells itself how and helpDill make thevale. Free licsorfares. Our men earnas highas New York. mile -Parket" Radio. particulars. (Copyrighted.)Write W. T. 025.00 u .eekly Writefordemonstrator. with musk.- l'ay's 100'7.Spencer Radio, Greene, 903 Barri-Ler Bldg., Wasl-Ilitttn, Memos Beacon Bldg., Dept.491,Boston. Ds pt.21. Akron. Ohio. D. C. Mass. For Boys and Girls Miscellaneous D on't sellforethers -Employ B OYS. GIRLS Earn Christmas Money! Patents sourielf.Make sour own produels.Toilet Order30 setsSI. NicholasChristmas PracticalConcentration.$1.60. Mag- xrt Irks.lunnehold specialties. etc. 500% Seals. Sell for 10cset. When sold re- Inventions Commercialized.PatentedI $3.00.keeping$2.00. No Work - net leForce.$2.00. %Alining Personality. Fl profit.Valuable book free.Notional Sci- turn free. Martens Pub- unpatented. Write. Adam -her entific Laboraturies, 1332W Broad.Rich- Lust Fun. St.Nieholas Seal Co., Dept. $2.10. Circulars co 201 Enright. St. Louis. Mo. mond. Virginia. Itroniclyn. N. V. lisher,1St'. Burlington,Iowa. January, 1930 Science and Invention 863 Classified Advertising-Continued Photoplays Real Estate Punchboards-Hottest. largeststoney. Free! Song Writers' Guide. B making line ever offered. Season starting. 1)-::4.13-.7Elio. Green Ilia). Wis. S For Photo.lay Plots.Stories ac- PECAN. Orange -Figgroves "On the Ite.1 commissions. Nothing to carry. cepted any form, revised. criticised. copy- Gulf." Monthlypayments. Guaranteed t'atalog FREE.Art!NI & 1, Sale, Sul righted. marketed.Estab. Ed:.Booklet core. 111g quirk return,Sigitirban Or - M. Adams. (Itleago. free. Universal Scenario Co.. 293 Western choral. Dept. N..HIloNi.BI--. Stamps & Santa Monica Bldg., Salesmen Wanted EARN a year's pay every month: others 105 Stamps.Egypt.etc.. 2e. Album do; you ens.Neon Electric Meng. Belo. coteillustrationAL3e. Bullard,Boston. Punchboard Salesmen. 510.1100 Yearly. K. 3912 N. Western Ave.. Chicago. BB, Mass. Printing Outfits and Supplies New Line.All fast seller,. Lowest price.. Pull commission on repeat business.Cata- logFree. Hurry! Puritan Novelty Co.. Telegraphy Print Your Own cards, stationery. circu- 14119 Jackson. Chicago. Songwriters lars. advertising. etc.Junior press. $5.90; Sell 51.500 Insurance Policy $1.00 joh Pr,:Seq. $11: rotary. 8149.printfor Yearly. Learn Morse and wireless telegraphy. Big Every man. woman ',respect.Big salaries. Tremendous demand. Expense. others;hig print!. Easy role:furnished. profits. Establishedlifeincome. 17iiited Song Poem Writers:"Ittel"Prop.:J. low. can earn part. Write for catalog presses. one. paper, etc. StalesIteeist ry.Tnwn,end and Superior, lion. Catalog tree. Dodge's is,: 'mender, pilot.210-1N, hey tone. Institute,StoneStreet.Valparaiso.In- ri.pany, (16. Meriden. Conn. lo'Is 3-, Chicago. diana. MODEL BLUEPRINTS Correct-Easy to Follow 1-2 Horizontal Steam En- 12 13th Century Man -of- 22 "Santa Maria," com- 34 Airplane Engine 50e gine details set$1.00 War 50c plete SW: 3-4 Boiler construction for 35-36 Motor Winch 75c 50c 23-24 Model U. S. S. Ports- above set$1.00 13.14 Chinese Junk ....set 37-38 Vertical Steam Engine $1.00 mouth set$1.00 5 880 Ton Bark sac 15.16 Electrically, Driven 39 Cannon 6-7 Twin Cylinder Steam Automobile set $1.00 25 Building a Model 50c Tugboat 50c 40 Steam Roller 50c Engine andBoiler 17 Roman Ballista 50c set$1 00 26 Twin Cylinder Marine 41 PrairieSchooner... 50c 8-9 Gasoline Fir d1.oco- 10.19 Simple Steam Engine. Engine 5Uc Lincoln Sport Biplane motive set$2.00 set 50c 27-31 U. S. S. Truxton $2.00 (man -carrying).... $6.75 10-11 U. S. S. Constitution, 20-21 How to Build a Re- 32 Sopwith Biplane 50c Gerber Monoplane "Old Ironsides"set$1.00 fleetingTelescope.. $1.00 33 Speed Boat 50c (man -carrying).... $1.00 .I n3 One :OW Ca I: cad ',Nein'sits up,/ is at all handy with tools, Toll find no difficulty in following Nor simple explanatory diagrams.Many sport planes and mown/Janes builtfront our plans arc flying daily, thus attesting to the accuracy of the blueprint details.Satisfaction gua,antecd. Send Orders to BLUEPRINT DEPARTMENT, SCIENCE AND INVENTION, 381 FOURTH AVENUE, NEW YORK CITY INDEX TO ADVERTISERS

A D K P PAGE. PAGE PAGE PAGE. Airplane Spruce 850 Drake, Frederick J. & Co. 851 Kirk, \V. J. 855 Page Davis School Advertising.844 Allied Radio Corporation 864 Dryer,J. A. 856 Patterson School . 851 .\ mericati Correspondence School L Piccadilly Hotel . 840 E 858 of Law Laboratory Materials 836 Polachek, Z.II. . 838 American Sales Company 859 Evans & Co., Victor J 341 I.acey & Lacey. 940 Projectionist Sound Institute American School 842-773 8.1.1 Excello Products Corp. 850 Landon School, The 834 Publishers' Classified Service S47 . 836 American School of .\viat' I.a Salle Extension University 836 American School Photography.. 861 Lederer School Drawing 857 R \ merican Technical Society 854-846 First Hawaiian Conservatory of Leonard, A. 0. 859 Radio Institute of America . 829 Music, Inc. 844 American Telephone & Telegraph Liederman, Earle 832 Radio Training Association Co. 845 of Fisher Mfg. Co. 840 . Lincoln Airplane Schopl 848 America 775 Anitainstitute 861 Franklin Institute 853 Randolph & Company 838 Arkograph Pen Co...... 844 Loconta Publishing Co 852 Freethought Press 835 Lyons Mfg. Co. Roat & Lohman 845 Arms, I..\. 850 846 a R. B. Specialty Company 854 Andel & Co.. Theo M . Inside Back Cover .... Gaston Mfg. Co. 845 S McCraw -Hill B Gerold Co., The 861 843 Sasnett, Edward C. 838 McSweeney Electrical School 857 Schoolof Engineering ofMil- Bastian Brothers Company... 850 Gilson Slide Rule Co 857 Marvel Mfg. Co. 856 waukee 850.857 Ilatenburg, P. J. F. 855 Gotlieb, Edward 838 Mead Cycle .. 859 See -JayBattery Company 853 Bernard & Heller. 840 Graphologist 848 Metal Arts Company 840 Shure Bros 848 Bliss Electrical School 838 Gregg Publishing Co 856 Metal Cast Products Co 861 Sinclair, Jas 86t Bogue Institute 848 H Miller, Carl 838 Smith & Smith 857 Brown, A. M 949 High Frequency Laboratories. 847 Miniature Ship Models.., 830 Strongfort Institute 844 Bureau of inventve Science.. 840 High School Home Study Bureau 855 Model Woodworking Company. 858 Studebaker Corporation of Burns, Farmer 856 America, The I Tolta rt Bros 850-853 Motor Institute of America....848 777 Studebaker, Jr. 854 C lIoniginan, A. 858 N Campbell, Co. Wm. 851 Hoollwin, Ch'ts 859 T Howard Engine & Mfg. Co National Electrical School Chicago S:Ivage Stock Store 858 848 Tamblyn, F. W. SecondCover National Model Aircraft 852 840 Telepex Company 842 Chicago Stock Cear Works 844 National Radio Institute . 769 Thorola Radio Products Conn, Ltd., C. G. 857 Ideal Aeroplane & Supply Co , National S...hool Visual Education 852 846 Inc. 852 Townsend Labs Coyne Electrical School 771 New Method Nlig. Co., inc. 846 861 Independent Electric Works 853 Tenor Banjo Studios 858 Craftsman \Yowl Service.... . 846 New York Electrical School....844 International Correspondence Trilety, M Crusader Apparatus Co. 842 Newell Pharmacel Co. 850 858 Schools . 834.844-861 New York Institute of Pho- U D International Typewriter Ex- tography change 858 848 U. S. Model Aircraft Corp Dayton School Aviation S50 851 inventors Service Bureau 840 North American Institute 846 Deagan, Inc., J. C. 842 Universal Aviation Corp. 856 Institute of Applied Science 859 Northwestern School Taxidermy 842 Delta Specialty 831 O Detroit School of Lettering . J 848 Western Radio Mfg. Co. Dolte, Engineer ...851.856 949 Jeffries Transformer 859 O'Brien. Clarence A. 839 Whirlwind Mfg. Co. ....Back Cover Douglas, Lyle 861 Jenkins Corp. 859 °nal', D. W. 834 Wilson, George 849 While everyprecaution is taken to insure accuracy. we cannot guarantee against the possibility of occasional change or omission in the preparation of this index. an Science and Invention January, 193(1

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Address 711 W. Lake St. Dept. D-4 Chicago, III. J City State .1 JUSTOUT!-Latest Exact Information from A to Z! We take pleasure in announcing: "AUDELS NEW ELECTRIC LIBRARY" New and More Uses for Electricity offer great opportunities tomen who can handle this power correctly. Modern electrification of industrycalls for trained men who know how to handle electricity accurately. Simple as A. B. C.-"Audels New Electric Library" gives latest, exact information from foundations of electrical practice to latest modern applications. This is a NEW practical and theoretical course in electricity for home study and ready reference. Here are the answers to your questions, giving ycu the real dope that every electrician must know. They chart your knowledge, taking away the uncertainty of guess work. As Easy As ABC

kffr;)01 Latest information, fully illustrated, covering: Fundamental Principles and Rules of Electricity, Magnetism, Armature Wind ing. Repairs, Dy- namos.D-CMotors,Construction, Installation, Maintenance and Trouble Shooting. Tests and Testinginstruments, Storage Battery. Construction and Re- pairs, Alternating Current Prin- Books C ciples andDiagrams. Power Fac. tor, Alternators. Transformers, A -C Motors. Windings. Recon.Now on Sale netting, Converters, S witches & Fuses. Circuit Breakers, Relays,5 in Preparation Condenses*. Regulators, Recti- fiers. Meters. Switchboards,The Library contains 12 Power Station Practice. Housebooks-the first 7 books Light & Power Wiring, Circuits,containing 3600 pages with High Teision, Transmission. Plans. Calculations, Code, Elec-thousands of diagrams and il- tric Railways,Signals, Elevators,lustrations are now ready; the Hoists & Cranes, Gas Engines,remaining 5 books are in prepara- Auto & A ero Ignition, Starters, Radio, Telephone. Telegraph,tion. A pocket-size, flexibly bound Bells & Sip mils. Motion Pictures,seriesthatis valuable wherever Talkies, Lighting. Illumination,electricity is used. Electric Refrigeration, Heating. X-Ray.Plating.Welding,Pumps. Beautiful, timely books for service- NEW! Compressors. Domestic & Farmpocketsize; completely illustrated withdia- Appliances. An Electric Calcu- SATISFACTION GUARANTEED! lator for Engineers and Mechan-izrams and charts; simplified, easy to read `AudelsNewElectric Library" ics, Practical Mathematics forand understand. No electrical man can afford is backed by our 50 -year record Ready Reference. A New Elec-to pass up this opportunity.Extremely low tric Dictionary & Encyclopedia as helping hand publishers.Satis- of Words. orice; buy on your own terms. faction always guaranteed. IM 4mm. WIN= IMM IM= f=1. BUY ON YOUR OWN TERMSTHEO. AUDEL & CO., I D PLAN I-ONE BOOK A MONTH 65 West 23rd St., New York, N. Y. Please enter my subscrip to "Au tele New Electric Library" to consist of twelve volumes. price 11.50 s. volume o10.50 for the seat,' Please ship me the NEW "Audels Electric Library" on the volumes now ready). Mail one volume each month and as they are re- plan marked (X) - ceived. I will mail you 11.50 -prompt IY PLAN 1 -.PAT 50E OR MORE A WEEK PL use strip me fur one week's free trial the first seven volumes of "Audels New Electric Library." $1.50 each (110.50 for the seven vol- NAME umes now ready). The remaining live volumes to be mailed as issued at $1 50a volume. It satisfied. I will mad you 50c or more each week as payment for the first seven hooks and I will pay for the last five numbers as I receive them at $1.50 each. ADDRESS CI PLAN s-CASH PRICE 09.198 Please ship me postpaid "Audels New Electric Library" for which I encloseremittance$9.98 in full payment for the seven volumes now ready. OCCUPATION You are to ship me on one week's trial the remaining five volumes as they are issued for which I will either pay 41.50 each as received or return to you. This price is based on 5'cash discount. EMPLOYED BY 3. 1.Jan. Over the Mountains front Los An des 559 Miles GAS on GAS

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GallonsofGAS Think of it!FIVE HUNDRED FIFTY-NINE MILES over rough mountainous country burning only ELEVEN GALLONS OF GASOLINE. Imagine more than FIFTY 'MILES to the GALLON. This is what the WHIRLWIND CARBURETING DEVICE does for D. R. Gilbert, enough of a saving on just one trip to more than pay the cost of the Whirlwind.

THEWHIRLWIND SAVES MOTORISTS MILLIONS OF DOLLARS YEARLY Whirlwind users,reporting theresultsoftheirtest:,are amazed at the results they are getting. Letters keep streaming into the office telling of mileages all the way from 22 to 59 miles on a gallon. resulting in a saving of from 25 to 50'; in gasbills alone. Mark H. Estes writes:"I was making 17 miles to the gallon on my Pontiac Coupe.Today, with the Whirlwind. I am making 35 5/10 miles to the gallon.Am Iglad I put it on?I'll say so!" P. P. Goerzen writes:"I made an actual test both with and without a Whirlwind, getting1.3!.; miles without and 94 6/10 miles with the Whirlwind, or a gain of 21 miles to the gallon.The longer the Whirlwind isin use on the machine, the better the engine runs, has more pep and quicker starting.It makes a new engine out of an old one, and startsatthe touch of the starter button." R. J. Tuip:"The Whirlwind increased the mileage on our Fordtruck from 12to 26 miles to gallon and 2151inspeed. We placed another 'on a Willy's Knightand increased from 12 to17 miles per gallon. Arthur Grant:"I have an Oakland touring car that has been giving me 15 miles to the gallon average, but I can see a great difference with the Whirlwind, asitclimbs the big hills on high and gives me better than 23 miles to the gallon of gas, which is better than 50!',1 saving ingas." W. A. Scott:"I had my Whirlwind for three years.Winter and summeritgivesthe same perfectservice.instantstarting,smoother running, and what I saved in gasoline these last few years has brought other luxuries whichIcould not have afforded previously:. Car owners all over the world are saving money every day withthe Whirlwind, bes:des having better operating motors.Think what this means on your own car.Figure up your savings-enough for a radio-a bank account-added pleasures.Why let the Oil Companies profit by your waste.Find out about this amazing little device that will pay for itself every few weeks in gas saving alone. FITS ALL CARS GUARANTEE In just a few minutes the Whirlwind can be installed on any make No matter what kind ofa car you have-no matter how big a gas ofcar, truck, or tractor. It's actually less work than changing your eaterit is-the Whirlwind will save you money. We absolutely guar- oil, or putting water in the battery. No drilling, tapping or changes antee that the Whirlwind will more than save its cost in gasoline alone of any kind necessary.It is guaranteed to work perfectly on any make within thirty days, or the trial will cost you nothing.We invite you of car truck or tractor, large or small, new model or old model. The to testit at our risk and expense.You are to be the sole judge. more you drive the more you will save. FREE TRIAL COUPON MI= 11=111 =El SALESMEN AND DISTRIBUTORS WHIRLWIND MANUFACTURINI: CO. WANTED I 99'0.70.A Third,.treet, Milwaukee. I Gentlemenl'ott may send me full particulars of your Whirl, wind( arbureting device andfreetrialoffer. This doesnot Free Sample and $100.00 a Week Offer I obligate me in any way whatever. I Whirlwind men a -e making big profits supplying this fast -selling device Name thatcar owners cannot afford to be without. Good territoryisstill open. Free sample offer andfullparticularssent on request. Just I Address check the coupon. City I County State ...... WHIRLWIND MANUFACTURING CO. IriI 0('heckhere if you are interested in full or part timesalesmen position. 999-70-A Third Street Milwaukee, Wisc. m mai =MI EMI NM WWI NI=