)Unninger's Amazing Buzz Saw Illusion Prizes for Best Solutions

SEPTEMBER ti 11

)unninger's Amazing Buzz Saw Illusion Prizes for Best Solutions

Dr. Worden's $600,000 Hobby By Alfred M. Caddell www.americanradiohistory.com ßes4Gallonof CAS . ßt0 O ...

...... ES i. Humidifier to eit. Carbon Eliminatot Man with Car for Makes of Cars, Trucks, Tractors Spare or Full Time all and Engines $350 to $1500 a month An amazing Scientific Humidifier has been patented throughout the 1 man $4,939.66 in 3% months. Another $1,656.60 in 58 days. World that beats any ever got out. It makes engines run ALL THE $5,150.00 in 5 months to another. TIME with the same wonderful efficiency they do on a cool moist night. It gives MORE BIG MONEY can be-IS being made. pep and power, HIGHER top speed, eliminates hard carbon, and gives AMAZING mileage. Fords report 28 to 42 miles per gallon. Other makes (both American and Foreign) report Fitting Motors With Vix marvelous increases of % to double mileage. Some of the best records are: One man. sold 8 first morning. Another sells all 3 men can install. Miles Miles Miles Miles Another's profits as high as $100.00 Buick. 281/2 Essex 32 Nash 30 Pierce Arrow 22 a day. Cadillac. 211/2; Ford (Model T)....42 Oakland 31 Pontiac 31 VIX sells itself by 8 STARTLING Chevrolet 41 Ford (Model A)....40 Oldsmobile 341/2 Rao 261/2 demonstrations BIG, STUNNING, Chrysler 30 V, Hudson 23% Packard... 211/2 Studebaker 29 ASTOUNDING -DEMONSTRATIONS. Dodge 3111/2 Hupmobile... 241/2 Plymouth.. 29 Whippet 41 Successful VIX men make MORE MON- Durant;.... 41 V, Marmon 211/2 Graham-Paige.... 231/2 Willys- Knight.....29 EY than they ever made before. And Hundreds of Other Wonderful Records on ALL American and Foreign Makes Try This New Principle Free Trial Gas Saver AT MY RISK Try this wonderful VIX Moisture Humidifier and Carbon Eliminator AT MY RISK on YOUR OWN CAR to prove that VAPOR MOISTURE (drawn from Radiator to Engine) gives you that wonderful night driving effect ALL THE TIME with MORE mileage from gas and oil- eliminates hard carbon i accumulation - gives MORE power, a SNAPPIER, PEPPIER motor. FASTER acceleration, a SMOOTHER, QUIETER running engine and HIGHER top speed. VIX will PROVE ITS MONEY SAVING MERIT on your own car by 8 DEMONSTRATIONS- conducted by yourself AT MY RISK -the most SENSATIONAL, most ASTOUNDING, most CON- VINCING DEMONSTRATIONS you ever saw. If you don't find from your tests that it does MORE than I claim, return it and it COSTS YOU NOTHING. I want wide- awake, hustling, County, State, Province and National Agencies everywhere, part or full time, to make $350 to $1500 per month filling the great DEMAND for this wonderful invention wherever introduced. Write for my FREE TRIAL and MONEY MAKING OFFER. Use coupon below. WALTER CRITCHLOW Inventor and Manufacturer,863- KStreet, WHEATON, III., U. S. A. Pictures here and at top show Model `B" VIX attached to my own New Model A Ford. This car is wonderfully im- FIOEEV!IV proved in performance with the VIX Moisture of fer aII NOW Humidifier. So is every Auto, Truck, Tractor. WALTER CRITCHLOW Taxi, Bus, Marine, Sta- INVENTOR and MANUFACTURER tionary and Aircraft En- 1 gine, both American and 863 -K Street, Wheaton, Ill., U.'S. A. all Foreign makes. Please send me 'without obligation or charge III your FREE TRIAL and MONEY MAKING N GUARANTEED TO VIX OFFER. to 1/2 Gas Name Carbon AYE.1/4 Cleaning s Engine Repairs Address or Costs You Nothing Town State

www.americanradiohistory.com September, 1929 Science and Invention 385

!. Have your the Courage to take it?

--This $2000,000 Çuarantee of aJobanaRaise

OF course you'd like to earn $50 or $75 or $100 a week -you'd like to do J more interesting work -you'd like to get into a line that offers a real future -but do you know how to go about getting these things ? If you have been thinking of "taking a course" but have held back because you were afraid you didn't have education enough to learn better -paid work -if you have hesitated to take the risk that it would actually land you in the better position and increase your salary -then here's the best news you ever heard in your life! I want to tell you about DRAFTING, and show you that it offers you everything in pay and opportunity that you could hope for. I want to show you that a fine Drafting job is now easily within your reach. And I want to set before you an amazing plan which we have worked out with the co- operation of some of the biggest employers and engineers in America, to prepare you at home, in spare -time, get you the job and raise Get this your pay -absolutely without risk of a penny on your part. Come Into DRAFTING! 'No-Risk" Plan! "Only one other »tan and I, of six taking Cali- I wish I had the room here to tell you all about DRAFT- f ornia State Boardexa»t- Thousands of men -not a bit smarter than you, with no more schooling ING -how it has become the most important jitation for Archittti, or experience -have gone from poorly paid positions as clerks, mechanics, branch passed. Then I realized the of every kind of manufacturing and building thorough and practical building trade workers and laborers into Drafting positions paying $50 construction work-how fascinating the work is training given by Ameri- to $100 a week, with our help. Now with a job and a raise waiting for -the fine bunch can School. I»18 months of fellows I have gone from tracer to you as soon as you are ready for it, all it takes is the COURAGE to go you'll work with -the big salaries paid -the Chief Draftsman, in wonderful chances for advancement. charge of all architectural after it -now if you remain in the rut it's because you choose to, not How, while Draft- and engineering work in you have to. ing is white- collar office work, it is hooked up closely one of the oldest offices because here." with big projects and big men, and offers the thrill that R. L. WARREN, goes with making plans Los Angeles, Calif. which govern every move of the men who do the work. All this inside dope takes a Drafting Lessons 36 -page book to describe and I'll be glad to send you a copy free when you mail the coupon for my Actually FREE to no -risk job and raise.t_ plan. show you how interesting Director Extension Work. and simple Drafting is THE AMERICAN SCHOOL " tilteiz I started Ant r- Dept. 11.653 Drexel Ave. and 58th St., Chicago, Ill. ican School training in Maybe you think Drafting is "over your head" it 11 e Spring of 1915 I -that Please send without cost or obligation, 3 Drafting was working 14 hours a takes artistic talent or some ability you haven't got. In that Lessons, 36 -page book with the inside dope about t ght, seven nights a week case you have a pleasant surprise coming to you. For I'll be Drafting and your no -risk plan and guarantee to for $1.83 a night. That glad to send you the first three lessons from our home- train- prepare me, to place me and raise my pay, or no cost. Fall I got a job in the i ng to you drawing of s mechani- Engineering Dept. of a show that the plansi purely large firm near here. To- cal, easily learned and the mostinteresting kind of work you Naine day I work 5; days a ever tackled. It takes little enough courage to look into this week and my salary is wonderful opportunity -just mail the coupon and see for yourself how you St. No larger than I ever dream- like Drafting and our guaranteed way to get into it. ed of when I began that course in Mechanical City Slate Drafting." D -653 .B. H. SEAVERNS, Dept. Drexel Ave. Age Occupation South Bend, Ind. The American School and 58th St., Chicago, I11.

www.americanradiohistory.com This Issue Contains These UP-TO-THE-MINUTE Articles by WELL-KNOWN Authors

General Science Aviation California Wins !- Frontispiece 388 California Wins 1- Frontispiece 388 -Editorial 392 Crack Ups 402 Dunninger's Amazing Buzz Saw Illusion -Over Giant Voice Helps Zep Land 412 96250.00 in Prizes for Best Solutions 394 Aviation Up -to -Date 416 Dr. Worden's $600,000.00 Hobby 396 Smashing Aviation Records 420 By Alfred M. Caddell Building a Sport Plane Part 2- Conclusion.... 428 Slater Refuses Our Spirit Test 398 Hints on Flying a Glider 431 Television in Colors 400 By Dr. Herbert E. Ives, Member Technical Staff, Chemistry and Electricity Bell Telephone Laboratories Television in Colors 400 Crack Ups 402 Experiments With Little -Known Chemicals 426 By Joseph. H. Kraus Wrinkles, Recipes and Formulas 435 Stereoscopic Movies With Color and Voice in the Making 405 Home Movies By H. Winfield Secor Animals That Learned to Fly 406 "Home Movies " -A Monthly Department 421 By Dr. Ernest Bade, Ph.D. Conducted by Don Bennett Scientific Progress 408

Coal Miner's Job Safer Than .Yours ! 410 Automotive By Alvin F. Harlow The Truth About Gasoline Savers 422 Giant Voice Helps Zep Land 412 By George A. Lacers, Automotive Engineer The Modern Sherlock Holmes 413 Motor Hints -A Monthly Department 423 Valuable Time and Labor Savers for Your Home 414 Aviation Up -to -Date 416 Television Is Education Worth While Opinions a College ?- Television in Colors 400 of Eminent People 418 Smashing Aviation Records 420 Magic-A Monthly Feature 424 Radio By Dunninger You Can Call Your Home From Moving Train 438 How a Roller Coaster Demonstrates Relativity 425 A Radio Robot 439 By Donald H. Menzel, Ph.D. New Radio Devices 440 What Articles Do You Like Best in SCIENCE AND Radio Oracle 441 INVENTION ? 427 What Our Readers Think 436 How to Make It Scientific Humor 442 Building a Sport Plane-Part 2- Conclusion... 428 Latest Patents 443 Wood Turning 432 The Oracle 444 By H. L. Weatherby Financial Article -- "How the Stock Exchange How to Make It 433 Works" 446 Shop Mechanics -$10.00 Monthly Prize 434 By Alfred M. Caddell Wrinkles, Recipes and Formulas -Illustrated 435 EXT MONTH When Fate Tricks Tricksters! elimination of the "booming" and reverberation found Dunninger, peer of magicians, will relate some un- in many auditoriums. usual experiences of fellow -workers in the mystic arts, when the magic machinery did not always work accord- Glands ing to specification. Some valuable information for the layman on the why and wherefore of our glands -a subject everyone should Playing with Death! he familiar with today. The article is by Dr. G. A. Some unusually interesting pictures showing how "the Estabrooks. other half of the world" makes a living. Dust! Making Sound Behave How nlanv tons of dust do you think there are in How the latest scientific discovery has resulted in the the atmosphere of a great city?

AND INVENTION. Published 1879. Title registered at the U. S. Patent Office. possessions; Canada and foreign countries, $3.00 SCIENCE Publications, monthly by Experimenter Publications, Inc., at Copyright, 1929, by Experimenter a year. Mackinnon -Fly Publications. Experi- Inc. The contents of this magazine must not be menter Publications, Inc. Novel Magazines Corp. 184 -10 Jamaica Ave., Jamaica, N. Y. En- full credit to the pub- reproduced without giving Executive and Editorial Offices, 381 as second class matter, at the Post Office lication. Fourth Ave- tered N. Y. at Jamaica, N. Y., under the Act of March 3, Subscriptions: $2.50 per year in U. S. and nue, New York City, 386

www.americanradiohistory.com September, 1929 Science and Invention 387

Not by Correspondence All PRACTICAL Wortrat

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www.americanradiohistory.com 1929 388 Science and Invention September,

California Wins! Women's Altitude Record Unofficially Broken Miss Marvel Crosson, San Diego, California, flier, recently drove The present record of 20,270 feet is held by Mrs. Louis McPhet- her cabin monoplane to an unofficial height of 24,000 feet on May ridge Thaden, of Oakland, California. In East St. Louis, Illinois, 28 at Los fíngeles, California. Miss Crosson left the airport at on the same day that Miss Crosson made her flight, Barney 11:17 J. M. and landed at 1:23 P. M. The temperature was Zimmerly broke the world's altitude record for light planes when estimated to be about 15° below zero Fahrenheit, at the highest he reached a height of 24,600 feet. As yet both records are point of her flight. unofficial.

www.americanradiohistory.com September, 1929 Science and Invention 389 I Will TrainYou at Home to Fill a Big-Pay Radio Job IF you are earning a penny less than $50 a week, You can build send for my book of information on the opportunities in Radio. It's FREE. Clip the coupon NOW. A loo circuits with flood of gold is pouring into this new business, cre- ating hundreds of big pay jobs. Why go along at $25, the sixbig outfits $30 or $45 a week when the good jobs in Radio pay $50, $75, and up to $250 a week. My book, "Rich Re- of Radio parts wards in Radio," gives full information on these big Heres the jobs and explains how you can quickly become a Radio Igive you PROOF Expert through my easy, practical, home -study training Salaries of $50 to $250 a Week Not Unusual Get into this live -wire profession of quick success. Radio needs trained men. The amazing growth of the Radio business has astounded the world. In a few short years three hundred thousand jobs have been created. And the biggest growth of Radio is still to come. That's why salaries of $50 to $250 a week are 8375 One Month an not unusual. Radio simply hasn't got nearly the number of thoroughly trained men it needs. Study Radio and after only a Spare Time short time land yourself a REAL job with a REAL future. "Recently I made $375 in one month in You Can Learn Quickly and Easily my spare time installing, servicing, selling in Spare Time Radio Sets." Hundreds of N. R. I. trained men are today making big money Earle Cummings -holding down big jobs in the Radio field. Men just like 18 Webster St. you -their only advantage is training. You, too, can become a Haverhill, Mass. Radio Expert just as they did by our new practical methods. Our tested, clear training, makes it easy for you to learn. You can stay home, hold your job, and learn quickly in your spare time. Lack of education or experience are no drawbacks. You Jumped from $35 can read and write. That's enough. to $100 a Week "Last week I had the Many Earn $15, $20, $30 Weekly pleasure of earning $110 servicing and selling on the Side While Learning Radio sets. I have made My Radio course is the famous course "that pays for itself." I teach high as $241 in two you to begin making money almost the day you enroll. My new prac- as tical method makes this possible. I give you SIX BIG OUTFITS of weeks. Before entering Radio parts with my course. You are taught to build practically every Radio I was making $35 type of receiving set known. M. P. Sullivan, 412 73rd Street, Brooklyn, N. Y., writes, "I made $720 while studying." Earle Cummings, 18 a week. It is certainly Webster Street, Haverhill, Mass.: "I made $375 in one month." G. W. great sport to do this Page, 1507 21st Ave., Nashville, Tenn.: "I picked up $935 in my spare kind of work. time while studying." J. A. Vaughn 4202 Arsenal St. Your Money Back If Not Satisfied St. Louis, Mo. I'll give you just the training you need to get into the Radio business. My course fits you for all lines -- manufacturing, selling, servicing sets, in business for yourself, operating on hoard ship or in a broadcasting station -and many others. I back up my training with a signed agreement to refund every penny of your money if, after completion, you are not satisfied with the course I give you. Act Now -64 -Page Find ouf quick Book is FREE about this Send for this big book of Radio information. It won't cost you a penny. $450 a Month It has put hundreds of fellows on tho practical "I work in what I be- road to bigger pay and success. Get it. Investigate. See what Radio has obg pay y lieve to he the largest to offer you, and how cry Employment and best equipped Ra- Department helps you get into Radio after you graduate. Clip or tear out dio shop in the South- the coupon and mail it RIGHT NOW. west and also operate KGFI. I am averaging President 3. E. SMITH, President $450 a month." J. E. SMITH, Dept. 9WT, National Radio Institute Frank M. Jones Dept. 9WT Washington, D. C. 922 Guadalupe St. National Radio Institute Dear Mr. Smith: Kindly send me your big boots, "Rich Rewards in Radio," giving information on the big -money San Angelo, Tex. Washington, D. C. opportunities in Radio and your practical method of teaching with six big Outfits. I understand this hook is free, and that this places me under no obligation whatever. 'Joyme,,tSeivice to G Name .í pe Em all dddeces

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www.americanradiohistory.com 1929 1 390 Science and Invention September,

Jules Verne Comes ck to Life!

AMAGIC name -Jules Verne ! A name have huge heads and no bodies ; of the things that has brought untold joy to untold a man might well see and hear a thousand millions. years from now ! Who can fail to remember his famous novels, It's a thrill you've never had! For it deals "Twenty Thousand Leagues Under the Sea," with the Future, and the things your children's "From the Earth to the Moon," "To the Center children may some day actually experience of the Earth," and other equally imaginative and enjoy. triumphs of this world renowned novelist ? Few 6 Big Issues of AMAZING Jules Verne's vivid Get the next writers have ever equaled STORIES delivered to your home by the post- and still fewer have been able imagination, man. Read with a relish these profusely illus- these pictures of the mind so bril- to paint trated stories of a weird, but not impossible liantly in printed words. future. And now Jules Verne comes back to life! Comes back with stories that increase your As a special inducement we pulse and make your heart pound. For in offer all 6 Big Issues for a single SIMPLY AMAZING STORIES, the magazine of scien- $1. (The news -stand price is CLIP tific fiction, the famous school of authors who $1.50). And if you are not con- AND vinced AMAZING STORIES is have followed in Jules Verne's footsteps now MAIL offer you the fertile fruits of their imagination. worth twice the price, after read- In their colorful minds, the inventions and dis- ing the first issue, we will let you THE coveries still to come are already here. They keep it FREE, and send your COUPON dollar back. write of a voyage to Venus, that silvery star BELOW! -seen so often in the evening sky ; of cor- Sit down right now-, and fill out respondence with a mythical people on Mars; the coupon below. It is your in- of radio messages from still more distant surance against dull evenings

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www.americanradiohistory.com September, 1929 Science and Invention 391 CREEN GRID AC qER i R .5

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www.americanradiohistory.com SEPTEMBER, 1929 VOLUME XVII NUMBER I WHOLE NO, 197 ` a ARTHUR H. LYNCH, Editorial Director. Aviation Editor. H. WINFIELD SECOR, E.E., Managing Editor. AUGUSTUS POST, Financial Editor. JOSEPH H. KRAUS, Field Editor. ALFRED M. CADDELL, Marine Editor. T. O'CONOR SLOANE, Ph.D., Associate Editor. WILLIAM F. CROSBY,

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

CONSIDER for a moment the automobile. It We Can Relieve Congestion at suburban main is at once a great blessing and a great curse. highway intersections in many ways. The most Fundamentally it is more of the former. The obvious is the elimination of grade crossings -the manner in which we are using it -or failing to greatest single cause of delay on main arteries. We use it -is beginning to pull the balance more and more can utilize short detours, thus spreading the traffic toward the latter. Something must be clone about at congestion points and bringing it together again it. Something must be clone about it at once. on the open highway. We can educate folks to use There are at present many more cars than our the so- called "back- roads." Many of these roads are street and highway system can comfortably accom- in a better state of repair than the main highways. modate, and relief in the form of new and better We can have local newspapers point out the value of highways is not keeping pace with automobile pro- using these little -travelled roads, and publish maps duction. \\Te are going from had to worse and going showing their location. We can permit the intelli- fast. Automobile manufacturers now have a different gent use of higher speed on the open road and even sort of "saturation point" to worry about. through town on main highways. We can change Automotive executives and engineers have tried some traffic rules, now in force, which would be a to relieve the situation by producing cars that will hardship even on horses and buggies. accelerate and decelerate more rapidly. High speed Highway traffic, as bad as it. is, does not begin to engines and four -wheel brakes are doing their bit to compare with the traffic congestion in our cities. In enable more cars to pass over a given section of road this problem we have observed that most of the because they can be driven at a much greater safe traffic jams occur in certain comparatively small speed than older types due to the braking power and areas at just about the same time each day. quick acceleration. There have been better roads One of the greatest single contributions to this evil movements started in all parts of the country. They is the taxicab, but the fault originates with the pas- are of value but the problem continues to grow. senger rather than the driver, because the former Many urbanites refuse to own a car because the wants to get from one point to another by the short- city traffic takes all the joy out of the occasional trip est route -which many times is neither the quickest to the country. and the garaging facilities are too ex- nor the cheapest, because much better time can be pensive and they reach the conclusion that using a made where all traffic is made to run in definite car for business driving in the cities is more trouble channels with a minimum of dodging back and forth, than it is worth. Holiday traffic on the main arteries and with slow- moving vehicles directed in definite in and out of our large cities is a disgrace. It is not lanes. We should see to it that pedestrian traffic at all uncommon to find that we can make a run of should stop and flow with vehicular traffic. one hundred miles through the country in four And now we make a further suggestion and an hours and spend another two in covering the ten offer to assist in its execution. Located in the miles from the suburbs to the center of town. What traffic center of any large city we propose the station- can we do about it? ing of a captive balloon, similar to those used for ob- We can arrange for the laying of more, of wider, servation purposes during the war. In the observa- and of better roads now, with a view to the traffic tion basket we propose to have one or two traffic they will be required to carry five years hence. experts and a radio man, plus a radio transmitter We can take immediate steps to have our present and receiver. Located at several strategic points at streets and highways used to better advantage as the boundary of the heavy traffic zone, we suggest radio receiving equip- follows : police stations, equipped with We Can Prevent Parking, even for a short time, ment, under the direction of the observers. ill the busy sections of our cities, thus bringing about The observers could be supplied with special nearly the same result as widening the streets. cameras to photograph the traffic area at definite We Can Provide Many Garages specially designed intervals, and from these observations much helpful to enable cars to get in and out rapidly so as to information could be had and an immediate relief for house cars, which would, under our present scheme heavily congested areas could be provided by proper of things. block the street. The charges for a park- orders transmitted by radio to the street stations. ing service of this nature could he made on some We shall be pleased to co- operate with any city reasonable basis. A system or chain of garages, of traffic authority in working out the technical details this character might include many garages in a for the trial of this plan. fee could he - single city, and the payment of a single made to include the housing privilege for a definite period in any of the garages in the chain. A service of this nature would be of real value to the sales- man, the shopper, etc. Department stores and large office buildings could use garages in their buildings to good advantage. Many of the more modern buildings are being constructed along these lines. Certain "automatic" gar- ad- aging features could be used to extremely good Editorial Director vantage ill cases of this nature. 392

www.americanradiohistory.com September, 1929 Science and Invention 393

easy gays to Make 422an hour in Your Spare Time i', 1141110 Each of these plans, developed by the Radio Training Association of America, is a big money -maker. Set owners everywhere want to get rid of static, to have their sets operate from the electric light socket, the tone improved, and the volume increased, and transformed into single-dial controls. Phonograph owners want their machines electrified and radiofied. If you learn to render these services, you can easily make $3.00 an hour for your spare time, to say nothing of the money you can make installing, servicing, repairing, building radio sets, and selling supplies. Over $600,000,000 is being spent yearly for sets, supplies, service. You can get your share of this business and, at the same time, fit yourself for the big -pay opportunities in Radio by joining the Association.

Join the Earned S500.00 Spare Time Frank J. Deutsch, Penn.: "I have made Radio Training Association over$500outofRadio in my spare time." Radio Engineer In One Year of America Claude De Grave, Canada: "I knew nothing about Radio when I joined a A membership in the Association offers you year ago. I am now a member of a A membership need not cost you a cent! very exclusive organization of Radio the easiest way into Radio. It will enable The Association will give you a com- you to earn $3.00 Engineers, and my income is 225% an hour upwards in your prehensive, practical, and theoretical greater than it was." spare time -train you to install, repair training and the benefit of its Employ- and build all kinds of sets -start you in ment Service. You earn while you learn. Doubles Income in 6 Months business without capital or finance an in- Our cooperative plan will make it possi- W. E. Thon, Chicago: "Six months aflerl vention -train you for the $3,000 to $10,000 ble for you to establish a radio store. enrolled I secured the managership of big -pay radio positions - help secure e You have the privilege of buying radio larg2RadioStoreand doubled my income. " better position at bigger pay for you. supplies at wholesale from the very first.

ACT NOW -- If You Wish the Radio Training Association of America No -Cost Membership Plan Dept. RN -9, 4513 Ravenswood Ave., Chicago, NI. To a limited number Gentlemen: Please send me by return mail full details of ambitious men, we will give Special Memberships that of your Special Membership Plan, and also copy of may not -need not -cost you a cent. To secure one, write today. We will send your Radio Handbook. you details and also our Radio Handbook filled with dollars -and -cents radio ideas. It will open your eyes to the money -making possibilities Radio. of Nanne___

Radio Training Association of America Address .. 4513 Ravenswood Ave., Dept. RN49, Chicago, IFI. coy State . -

www.americanradiohistory.com September, 1929 394 Science and Invention

IiUNNINGFR'S Sensational Buzz -Saw lllusion Can You Solve This Mystery? More Than $250.00 in Prizes

together with INVENTION readers to this publication SCIENCE & More than $250.00 in prizes copy of Popular will be given an oppor- an autographed offering a solution 42 Awards Magic, Vol. 3. tunity of original idea was to to the famous Dunninger Buzz -Saw Mr. Dunninger's mystified hundreds of 1st prize $100.00 exhibit this illusion on the vaudeville Illusion that has fact that this thousands of theatre -goers the world 2nd prize 50.00 stage, but owing to the 3rd prize 25.00 stupendous sensation carries so much over. 10.00 Dunninger's travels, with his 4th prize necessary apparatus, machinery and a During 13 -5th prizes of $5.00 each 65.00 the illusion own two and one -half hour mystery corps of trained assistants, be too costly a proposition to pre- show, touring both this country and $250.00 would was known sent on the vaudeville stage today. abroad, the feature illusion 25 -6th prizes. This prize com- it Illusion, which not a subscription to With a full evening's performance as the Buzz -Saw bines year's matter. only created a sensation wherever pre- "Science and Invention" maga- was quite a different has baffled the most learned zine and a copy of "Popular Professional and amateur magicians sented, but ideas and minds of the entire world. Many ex- Magic and Card Tricks," Vol. 3, are invited to submit their offered, but up to date by Dunninger and autographed solutions and enter the contest to com- planations were him. Magazine value $3.00. not one possible solution of the actual by pete for the prizes. on page Dunninger modus operandi of this startling mys- See rules following The effect, in brief, of the Dunninger, Buzz -Saw Illusion is as follows: A tery, which was created by hypnotic has been forthcoming. contest, for ingenious minds, offering lady is apparently placed under After witnessing a private exhibition the sum of $250.00 (Two hundred and control, then lifted by two assistants the illusionist's fifty dollars) in gold to those submit- and put into a box just large enough to of this masterpiece of through art the editors of SCIENCE & INVENTION ting the best workable methods of pro- hold her. Her feet are put have arranged with Dunninger to pre- ducing this master mystery act. In two circular holes at bottom of the box sent to our readers the Buzz -Saw addition there are twenty -five prizes, where they remain in full view through- illusion and we are going to conduct a each consisting of a year's subscription out the experiment. Her wrists are

www.americanradiohistory.com September, 1929 Science and Invention 395

Here is an illustration which shows Dunninger's Buzz - Saw Illusion as it is staged. You are asked how this can be done in the most practical way. The awards in this contest are indicated in the blurb on the opposite page. Insert shows Dunninger who originated this illusion and successfully produced it.

placed under suitable steel bands on each side of the box and shackled in position by members of the audience, who are affixed to the box which are wound asked upon the stage FOR WAIST up on to a large drum manipulated to act as a committee by two assistants. and to see that every- FOR HANDS The girl being thus helplessly thing is done in a fastened in the box, it seems utterly fair and aboveboard impossible for her to move about, manner. The locks let alone make her escape. used to hold the SLIDES Next, a number of swords are wrist bands may be passed to committeemen and exam- A mñnnl:l' brought upon the CHAIN. ined, then taken by the performer stage by anyone in FOR FEET PIN and thrust through the box from the audience. These top to bottom. The swords enter locks may be of any the box at the top and project quite type desired. ,JI' a bit proving 1111111 c outside of the bottom, The box, contain- conclusively that the swords have ing the lady, is now entered and passed completely lifted on a skeleton era; Ka through the box and apparently track arrangement through the young lady. (see illustration), Here are the details of the fastenings in the wooden box of and two chains are the illusion. (Continued on page 455)

HERE ARE THE RULES

1. The lady is actually placed in the box, where 7. Each contestant may send in one or more solu- with those tied for will be paid to each contestant she positively remains throughout the illusion. tions which, if he desires, may be illustrated by so tying. diagrams or sketches. 2. No mirrors or special lighting effects are employed. 8. Solutions must be typewritten or legibly written 12. All entries must be in our hands at noon by hand on one side of the paper only. November 21, 1929. 3. Not for one moment are the projecting feet out of sight of the audience. 9. Solutions must be limited to 200 words or less. 13. From this contest are barred all employees of the Mackinnon -Fly Publications, Experimenter 4. No stage "traps" are used. 10. Prizes will be paid to those offering the best Publications, Inc., and Novel Magazine Corpora- tion, their relatives and members of their families. 5. Only "one" woman is used. workable methods for producing this illusion. 6. The box is actually sawed into two parts length- 11. Mr. Dunninger will be the sole judge. His 14. Mail all solutions to Joseph Dunninger, care of wise. This is not an optical illusion. word is final. In event of a tie, prizes identical this publication.

www.americanradiohistory.com September, 1929 396 Science and Invention Dr. Worden's $600,000 The World's Foremost Authority on Cellulose Chemistry Has Col- lected Upwards of Half a Million Dollars' Worth of Rare Postage Stamps

By Alfred M. Caddell

! Stamps ! Stamps ! The -boys are collecting That which started back in 1840, as a keepsake proposition, has now grown into one of the country's big home industries, numbering among its followers bankers, lawyers, doctors, the baker and the candlestick maker -and not to forget chemists, for this particular story is about a The above photograph shows Dr. Worden and Leo chemist. Millions of dollars' worth of canceled postage Rutstein in the laboratory. stamps, otherwise worthless in themselves, are traded in annually by thousands of business men hobbyists throughout Who Dr. Worden Is the world. Upwards of one hundred thousand stamp en- an thusiasts throughout the United States follow the trail of the DR. EDWARD C. WORDEN enjoys for as the foremost little square -inch stickers that provide transportation international reputation your letter and mine. The commercial value of odd and authority in the field of Cellulose Chemistry. rare postage stamps, both canceled and uncanceled, is be- He was Chief of the Aviation Chemical Division yond all computation, but it is safe to say that it approaches, of the. U. S. Air Service during the war and is if not surpasses, the billion -dollar mark. technical chemical advisor to the War Depart- The desire of possession, the same goal that gives dia- ment. He established aviation chemical stand- monds and sapphires their values, is behind the whole thing. ards for the United States Air Service, and also And aside from the commercial considerations, the building for the Allies behind the lines in France. of stamp albums is the basis of a most delightful hobby for For years Dr. Worden has been regarded as thousands of people, much as golf, bridge and radio supplies in the field of Chemical liti- an interest in life to others. the Supreme Court these stamp -collecting by sonne of They call themselves philatelists, gation. In addition, he is retained enthusiasts. And one of the most pronounced hobbyists in the largest chemical organizations in the world this line is Dr. Edward C. Worden of Millburn, New Jersey. on a yearly basis. Dr.' Worden does not possess the largest stamp collection Dr. Worden is the author of more than fifty in the world by far, but if he wanted to dispose of his col- books and papers on nitro -cellulose and his lection tomorrow he could probably cash it in for about compendium on that subject forms the basis of $600,000 -which means a hobby with a price. many of our collegiate courses on that subject. "I get a lot of enjoyment out of the game," is the way the hhe believe the reader will find the story about doctor puts it. "I went into it solely from the standpoint of of our a most interesting one, and we hope desiring to own rare, history- making mementoes his hobby it the profits that came with in- tell its about this eminent lives, and since I got into to have the author more creases in value have been amazing and tremendous. Not chemist in a subsequent article. that I make money from the hobby-I do not, for I do not -The Editors sell any part of my collection. I like to mount the valuable little things in my albums, and have stayed up many nights just to give an added touch to my designs. "Not all stamps of value are canceled issues, however. In fact, one may purchase what he believes to he an ordinary stamp or sheet of stamps at his post -office and find that he lias bought something of extreme value. Take the 100 inverted 24 -cent air -nail stamps of 1918, which appeared in the regular run of stamps. How much do you think they are worth? Well, today the value of these 100 stamps, which originally cost $24, is now $150,000, for less than a month ago one brought $1,500 at public auction ! "These freak stamps got into the hands of philatelists in this manner. One day, soon after the air mail was established, a young man appeared before the post -office window at Washington, D. C., laid down $24 and asked for 100 stamps. Howard A. Mount, the stamp clerk, handed out a sheet of the new issue and the youth started back to the he was employed as a messenger. Hardly is a of the Library, in may bank by which Above view Worden which -office when a postal inspector overtook be found more than 20,000 scientific volumes. The library had he left the post measures 40' x 80' and is 18' high. him. . " `Here, young man,' he called `did you just buy 100 24 -cent stamps ?'

www.americanradiohistory.com September, 1929 Science and Invention 397 Hobby

"`Yes,' replied the youth. `What's the matter ?' " `Something went wrong with the work when the plates Dr. Worden holding a sheet of reconstructed stamps. The were being prepared,' explained the inspector. `Four sheets border work surrounding this collection is done in pen and ink and is of those stamps were printed with the picture of the aero- the artistic handiwork of Dr. Worden himself. plane upside down. We caught three of the sheets before they got out, but you secured the fourth. So I'll have to issue ever made in this country. These stamps were put out ask you to return them and we'll give you 100 of the same by Robert H. Morris during his term as postmaster in New issue properly printed.' York City, which extended from May 21, 1845, to 1849. "But the youth refused to part with the stamps. He knew They were issued in 1845 and are known as a provisional that if there were only 100 of such freaks in existence that issue. That was at a time before the United States Govern- they must be worth considerable money, and he turned them ment started to print stamps. These stamps might stand at in at the hank with a report of the incident. The officials the head of provisional issues by postmasters. The stamp of the bank also refused to give them back and later they sold of this issue is black and the design contains a picture of them to a stamp expert for a reported price of $18,000. the head of Washington engraved from the famous painting 'Today Colonel E. H. R. Green, son of the late Hetty by Stuart. It is a five -cent stamp. Today, unused, it has a Green, famous financier, owns fifty -one of those stamps. I value of $100. Used, it would be worth $60. Of this issue own one and the other forty -eight are scattered. Dr. Worden's collection contains ten unused and fourteen "Then, too, fortunes have been made by persons who acci- pairs and fifty -six singles used. Their total value is more dentally found rare stamps. Sometimes valuable stamps are than $5,000. Each stamp, before being issued, was initialed. picked up in rubbish piles. Several years ago a junk man "With pen and ink the postmaster wrote his initials on brought into a New York stamp house a huge bundle of old the face of the stamp as evidence of its genuineness," ex- letters. Many of these letters, experts found, bore valuable plained Dr. Worden. "Think of what any postmaster would stamps. The junkman said that he had found them in two be up against today if he should attempt to initial every carloads of waste paper that were about to be sent to a New stamp he sold ! But those initials give these stamps a Jersey repulping mill. The stamp company immediately decided increased value." communicated with the owner of the paper and purchased In 1847 the Government started to issue postage stamps, the two carloads outright, hoping that further treasure and in that year two varieties were put out, one a brown would come to light. And it did, for they were rewarded five -cent stamp with the head of Benjamin Franklin and the with specimens with a value of about $15,000." other a black ten -cent stamp with the head of Washington. Dr. Worden has ninety -four postage stamps of the first Of the latter, Dr. Worden owns (Continued on page 477)

www.americanradiohistory.com September, 1929 398 Science and Invention

row -sumo it in the DAILY MIRROR. 37ontlay, ulne 24,1929: Spirit Mediums Reject $21 000 Chalkii e DISBELIEVER DRIVEN FROM At the left: El newspaper clipping f r o in "Daily Mirror," CONVENTION the 197i By FRANK CO$LING, describing what hap- rEW YO.RK:- ..:.;.:.__...... __:...... _...... lH:...... : ...... A, young reporter reports.prog pened to the "Science an intriguing assignment. sess.ozi and Invention Maga- AN OVE R BAN tCANC}7RUT.MSOf3ilftálì Several hünrlred spiritualists v...., field ' are having an ectoplasmic- zine" Investigating . ': - . r.. Qd%:_.-.° day at the Hotel Pennsylvania. Committee. Right: A -: Paávo Nurfni .. John .Slater, the k . of the spirit- chasers, is the prin- photo of the c h e c .: cipal attraction and the staunch- was for tMaa,. faith. He it which ready est defender of the if he was was who caused the unceremo- John Slater, :E %Pitti 1CATIONS.:.1N nious ejection:: :oí Joseph Dun. able to do what he finger, an avowed disbeliver --- who brought a certified check for claimed he could. We to the meeting, tò 136._ asked nothing more. paid on' proof of pychic accoin- ,TIIiA9.uant.:..

plishnient. - - Slater Refuses Spirit Test Medium Who Reads Messages Refuses One More for $21,000

newspapers had advertised that John Slater, the world- renowned medium, was going to demonstrate THE1spirit messages at the New York State Spiritualist meetings on June 21, 22 and 23 Left to Convention at their public at the Hotel Pennsylvania in New York. Repeated telephone right: H. desk to the effect that K. Fly, calls and letters arrived at the editor's Secretary we were afraid to challenge a real medium and that our and Treasurer prize award of $21,000.00 for spirit phenomena is merely of Experimenter newspaper talk. These individuals argued that here at last Publications, Inc.; was a medium who could and would take away the prize Dunninger,Chair- which we offer. In the interim other calls came from friends man of this maga- of ours ; newspaper men and women who had been talking zine's Investigat- and reported that these spiritualists ing Committee for to various spiritualists not even walk across the street for $21,000.00. Per- $21,000.00 check, and Joseph H. would Psychical Research, holding haps the sum was too insignificant, but if anyone will tell the Kraus, Field Editor of this publication, with the sealed message.

EVENINGVENING GRAPHIC The .ttnÖd Spiritualists Give Bounce To Inquisitive Doubters BROOKLYN -NEW YORK CITYL SATURDAY, JUNE 22 192 e- very Mollified i rstiettion committee of 6tochee and Invention YORK SUN usly thrown HE NEW THE NEW YORK TELL i of iÍ e conyntion of the general SPIRIT WORLD hSy I Spirltuaast^ f Now CTorkn State at the Hotel Penruyl -, last ton'. Shatters Thel,O. action followed the LINK REPEATS- 'SPIRIT' MESSAGES i Joe Dunninger furore causedCLLU ii b e challenge great" John W h a t a f w r "t he foreinmttcaeplatfor'tn AT SESSION Peace of Ghost Seance medium." to prove Ws supernatural of the newspapers $21,000 DEFI READ powers by reading a ten -word mes- se nm,Grtned i Baled had to say about If Slag could i!, m n ieveso teof of Harry Houdini Offers $21,000 to Slater, Hailed by do Friend the mitten d- above the our challenge to Spiritualists Give Dunning Investigator Is Ejected From Tumor, he would be given $21.100 Spiritualist General Assembly as "Greatest Medium of All," ort the spi and heck for that gee the. Air. at Their amountont waved to prove it. John Slater. Convention. ignored the challenge. A.. Annual Conference tor Answers to Two Questions in Sealed Envelope. group of huskies soon surrounded, members committee. of the thirty - ,Evert before the uproar¡ ribs- At n lively session ncluded Joseph wrprs -hi of the New John Slater, who In the expressed the Hanno,, Central Sank. He reader who urbances were reported' last e' third annual convention Gssioasl mind makes State. Assembly of Spiritualists, belles of the General Assembly of waved it aloft and he waved the en- l -lm t soprrnaturàl Meg among the local spirits, as the York ecptJ John Slater of Los Angeles sixty velopes, both with big red was seals. J ii. Krpas. Leld edti,, ai- :annual convention of Spiritualists, 1s the greatest meditm SOte e anq_)nyeatlptl. and H. H thirty -lhnd - Spiritualist platform In Medium Loses Calm. the New 'York General Assembly - an- Of them all ha, the spirits well un- I .l'n.ur coed vn night. At the Pcnn- It was [Hen that the spirits almost Spiritual., swung into stride a packed der control last Pennsylvania. éMime f 2.000 That .,ylvania Hotel they were nsweri deserted the athering of 2,000 - the Hotel l Johnnte evening's rink bedroom of of any ho mightht there was standing room only in the e Aoyond, felt h early n a last night for fir_t Of three Physical action with Great thequestionsore long and pay his 31, his 0.50 grand ballroom. , nt passed the word on to his 1,000 oublie.public demonstration, seemed forthcoming. Slater's cohorts : mer ccan his Itlew torhh nt -Il er'eTie order $2. a o Wok nanas on to But Slater, who, as related by the moved on Durminger. Dunnfrger'e ehetrei vol of a men, a said hl ma, regarded best met derssembly, left hème at the ten - rends stood up. sal Dunninger and who eie : >órean name mice of 20 because his family Slater, who had lust been preach- Spurns $21,000 t Spiritualist ir goat to represent the. scientific of calmness and Jilbn ell any claimed thought him crazy when he cheer, ing the advantages of Schnee Icon Dirt ávt you, mtigotlen ecommittee voices," reckoned without an old love, seemed to lose both fora mo- It - n. r. Sl terca!d ats T aga . Minn.., Onm enemy. Not Satan, whom lave will ment. Dunninger left protesting. Offer to Read Hidden Not r ep sg ás Te iieÓ.And as removedre bec from overcome, Ind Joe Dunninger. He offered to duplicate any ,Iirit- a B;Z rl.'"'' tutustatersmánsassed s'aie- r ual "feat performed by Slater. et nott hetic his -Routines Friend Pipes llp, t,%! religions wage -ft's not the (¡kale, though.' he 01 SI.ATr':1:. o ,il:,l.lpl,la- grew v h,thcten anda pepa ¿TU that ir,," able to to be associated with erpboys had predicted the same crater that h0 -was Joe, who used protested. "Any one who takes ltb. Ge, r.al eons sitting a. carry Houdini In exposing mediums. s previously). disproveandwin, Slatake Ablllty n "t 0 ey to talk to a,,i foe you 1n,bhyT'of ilh1piluali I.. is a'slu- ater e exasperated and Or. I on SILO Ì...rankly ayhe b 'I ¢ and would stake n a2 1,0!10 prize went to the moeting. lie paid Dunntnge 'was spluttering, gent of IMane spiritual, but he cares derml the would.he n be of and -' entey to New fork, There SHomans would not and got a good scat. So did four Mile fur materl'a1 t ux the bull- y left, but net Iv. ofm ate 'He's a vulture,. ' he finished with .a-such t ente ieurbanc anted Ina Homan -Catholicle'hu51h his friends. They listened while Slater. later why l he -nort here. .I've e,.ie heat. og messages to spirit - scurrilous asty. a Jewish plan rfdd Slater delivered While s ater a.ving Pkil t 'd not read Me letter and lleco calls: l U he In- young and old black and white. Will Continue Tonight. the money. T o scurrilous y t was said with lei [rom he platform, le,mnee foc an was m ,en.< Then Joe, who prefers to be called Slater, turrounded by admiring of delegates M o-annárd .I Wee og hitos .There tigatihhr nn- spoke up. ails had regained love and eçelved yTOné ai1e to- env "just Dunninger:' cohorts,. trual a but of tibor sag I had to lgntr' voice wasn't particularly gentle and pecce however, He will continue Mat nihuf . .1rAsturleance \o. F he was waving his arms. The sh ut tonight. 1,ciegates eerodned loyal to Ave x novas n su Ird sumota!e ssembl .vat up "And, my .dear MP! , there

www.americanradiohistory.com September, 1929 Science and Invention 399

AT THE SPIRITUALIST ASSEMBLY

fl graphic illustration of what happened. Strong -armed men promptly proceeded to JohnSlater, oust the members of the medium the "Science and In- who or- vention Magazine" In- dered the vestigating Committee. .N.Tryr Ammon; committee Inns ?2,1129. from the ¶1SPIRITUALISTS s é a n c e GIVE EDITOR room. `BUM'S RUSH'. While 1,000 infuriated spiritual 'F,qr YORK' HERALD TRiBt'NE21 Isis 000e1 "put him out," Joseph r Dunninger, editor of S tria lotlz oÍ-Iftz ZL"( : .'_ i .11 I Invention, got what is a gem Skeptic Oustéi,' known as Y cotheded $balllrrooRush" ts the i n. r :tij' eöm'eerno OOKLYN DAILY EAG r. Hotel Pennsylvania last night. With $21,000 The General Assembly. the of June 21, _. m.et 5 P. it::. CEPT(C EXPELLED Spiritualists were holding it meeting, John 0l s a npuncing HOTEL PENNSYLVANIA By 'spirit messages Saint mcnages Spiritualists MEDIUM SPURNS when Mì. Du - Left: A few ger'arose to say he had a ce titled check for $21,000 which he SLATER as BY SPIRITUALISTS more news- JOHN unninger Flaunts Check $21,000 OFFERED woulduld give Mr. Slater if he had' John Slater Is Relaying spirits answer questions in two paper clip- Baled envelopes Mr. Dunninger news From Other World FOR SPIRIT TEST Medium RefusesOffer to Tes held up- to the audience. pings. They Mr. Dunninger, equipped with a Skill for $21,000 nìlar tell a graphic ern It a, a Challenge offer, had been thrown out Man Who Tethers Cheak :of many spiritualistic meetings in story in them- the past,. and - e. was not disap- fl newspaper clip - istnrher, Disciple of Roo- WOMEti ACCLAIM 'tSEER'" pointed this time. selves. at Hotel Pennsylvania. Reporters tltén flocked aroùnd p i n g advertising dini, Acting for Magazine Mr. Slater, wanting to know why o h n he had the spirits slight Mr. Dun- J Slater's ap- While He john Slater of Pttiladel- Refuses to Answer Questions - By ishbel Ross ninger, but Mr. Slater severely hia, honorary member of the Gan- said to the members of the press: pearance at the s,y.nlne.yeer-nld Jon. Sidles. a m at Arlacmblp of Spiritualists, By Science Wgrker Yon must have been unary of,ree Nstlnnel was tj drinkinç" Hotel Pennsylvania ....hat, gi d refused to say more. latlon. w ln midst read - ving spiritual readings last nigh' lag messages t h e C in New York. spirit nihelied ual ention of spirit- John State;, mediad', was peaci100S a ttdience 1n the Pennsylvania lx night ualists ¿in the Hotel Pennsylvania, he when her of Joe nunnnger. m g people to their deceaseas ger5interrupted by Joseph DUnnin- who has Amur. the amie of Hou - cued ducones at the General Assembly o skeptic. dint nemesis of c voyance. a, end offered 521,000 Spirituals. In the Hotel Pennyivanla More than n50t if he would read the contents of a envelope. With this information fronight whenw which w moi in advance, Joseph H. might sea of sealed envelope. as convention te kantait- m splött oven, Slater ,,had been giving ding Kraus, Field Editor of SCIENCE AND INVENTION e piritruus s. snow "I have two queatlone' ham in seaters: MAGA- ras of letters for his dtenee `without envelopes. He tried ' ei Wit you undertake to ZINE, prepared andd epryeNx o .l two questions. One of them was a fac- ebaliruom.u However, clung epeaiO_JS,ignore Dunninger, who waved a cer- c onee or them without openings check he had o tiard.eheck back and forth as ht M nv lope for prim of 621,000/m simile of a question asked by a person now Mater I^the prrivalet wo rawer talked. Dunninger grew more lusts- eph Dunninger, mph, was epeaki deceased. e questions. tent, and a few personne sitting near Ir. The second was along the line of questions She meeting w ofdTar- I him Mined In, Slater became Pao him out! Throe him outi" then that Mr. mo and tenthuessm until Dun - aaperated and ordered the plrltual bellerera cried. ömger. a ' who is guardian of IM.000 ut of the haliyunor a!' 1ceptiic Is Expelled Slater answers. These messages were placed in en- nm offered by "Science end m uVe {IV- gMter tor e proor of the nsosnneson 14 /' velopes and appropriately sealed. sodlt message. cut in on the am la hle Ileeit al'Roman,CSthoitc astg flowing from tine platform. Church orb é Wow sñ synagogue, what wduld you Father hay So that there would be no question about the Gel. gmea Fromqp.Hefo s ou ", ta'H'nich'riley Sledlrltio a. proceeded to' $21,000.00 .. Dunningee in awards, Mr. H. K. Fly, Secretary and Ibnone H. Kraus, exof [aide at a L sña n r the dance Treasurer of our organization, appeared on the scene editors where they d Investigating a can get $21,000.00 r PsychicalPar orle1 Research. He nera Jed armed with a check drawn to John erx for e2í,000 on the ny Hne Slater, a photo- by walking either across the street or sank and 'Trust company Made graphic reproduction S by R. A. c- of which appears with this article. across the continent, we shall be more %;:n'4,`,;=11%`; Ezpeclme ter tr, Note that while the check was drawn on June 21st, it than obliged DunnSUS interruption. and at least will make an `óld _Wee be[ pen+ was not canceled until July 2nd, giving helf` Slater every attempt to do so. opportunity to put in his claim for it. Dunninger, However, the that is aside from the story. As long as the Chairman of the SCIENCE AND INVENTION MAGAZINE In- mountain wouldn't come to Mohammed, MohammeT decided vestigating Committee for Psychical Research, was on hand to go to the mountain. to start the ball rolling. H. Winfield Secor, John the Managing Slater is a world -renowned medium ! He demon- Editor, was ready to pay his respects to the winner, and strates his ability to read a message on the inside of a sealed three other committeemen, N. J. (Continued on page 460)

www.americanradiohistory.com September, 1929 400 Science and Invention

a CIRCUIT ! GREEN 8 TO 10 STAGE V.T. AMPLIFIER SCANNING DISC ARC LIGHT --- TO CURRENT SUPPLY D.C. /1 MOTOR) SYNCHRONIZING 9 o MOTOR

PHOTO -ELECTRIC) QUARTZ CELLS TO D C. OSCILLATOR SUPPLY

TO CURRENT f r SUPPLY

CIRCUIT 2

Miss Charlotte Papillon, dressed in bright colored cos- tume, seated before color television transmitter. CIRCUIT 3 The color television transmitter shown schematically; with vacuum tube (P.T.) amplifiers, scanning disc, quartz crystal controlled V.T. oscillator supplying synchronous motor, photo -electric cells, arc supplying scanning light pencil, etc. Television Moving images in natural colors are successfully transmitted and received over newly devised television system of Bell Telephone

SLOT FOR DIFFUSING SLAV Laboratories

Diagram showing how red, green and blue color screens cells which the re- necessary to obtain photo -electric -like together with their respective photo- electric (light or panchromatic plate -would be screen is modern orthochromatic sponsive) cells are arranged. A glass diffusing the visible spectrum. This requirement placed over the color screens. sensitive throughout has been satisfactorily met. Through the work of A. R. Olpin and G. R. Stilwell a new kind of photo -electric cell VER two years ago Bell Telephone Laboratories has been developed, which uses sodium in place of potassium. demonstrated a practical system of television. For Its active surface is sensitized by a complicated process O the first time successful representations of objects using sulphur vapor and oxygen instead of by a glow dis- at rest or in motion were transmitted electrically-over wires charge of hydrogen as with the former type of cell. or through the ether -for considerable distances. The re- The response of the new cell to color, instead of stopping production of the scene then transmitted was in monochrome in the blue -green region, continues all the way to the deep -the orange -red color of the neon lamp. Recent develop- red. Because the former potassium cells were responsive ments of the laboratories, however, have made it possible only to the blue end of the spectrum, objects of a yellowish to reproduce scenes with their true color values. The color appeared darker than they should have and the tone appearance of reality in the reproduced scene is thus greatly of the reproduced scene was not quite correct. This dis- enhanced. advantage applied particularly to persons of dark or tanned One of the most significant features of this new achieve- complexion. When the new cells are used in the original ment is that it does not require completely new apparatus. television apparatus and with yellow filters- similar to those The same light sources, driving motors, scanning discs, used in photographing landscapes in order to make the blue synchronizing systems, and the same type of circuit and sky appear properly dark -this defect is corrected and the method of amplification are used as in the monochromatic images assume their correct values of light and shade no system. The only new features are the type and arrange- matter what the color of the object or the complexion of the ments of the photo -electric cells at the sending end, and the sitter. It is the availability of the new photo -electric cells type and arrangements of the neon and argon lamps at the which makes color television possible by their use. receiving end. The outstanding contributions that have The development of color television has been greatly sim- made the present achievement possible are a new photo- plified by the fact that as far as the eye is concerned any electric cell, new gas cells for reproducing the image, and color may be represented by the proper mixture of just three the equipment associated directly with them. fundamental colors -red, green, and blue. This fact was To render the correct tone of colored objects, it was utilized in the development of color photography, and all the had been done in that field was available as Republished by Permission from Bell Laboratories Record. research that

www.americanradiohistory.com September, 1929 Science and invention 401

POWER FILTER,GREEN AMPLIFIER ARGON-* /E,) ® . TUBES SEMI-TRANSPARENT MIRROR

101- BLUE FILTER

RED FILTER

NEON TUBE OBSERVER

SCANNING DISC

Side view of color television receiver, si owing two argon tubes and one neon tube mounted behind scanning disc Note two disc driving motors L. Labs. POWER AMPLIFIERS and viewing hood used by the observer, A. Johnsrud, of Bell Tel.

TO COMMUTATOR TINFOIL SPIRAL WIRE r. SEGMENTS INSIDE OF TUBE

yj I RED Color television receiver in schematic form is here ¡CIRCUIT shown. Power amplifiers boost the incoming television RED TO -; i I I Ii II I ililil signals, which are led into argon and neon tubes as /l COMMUTATOR shown. Light fluctuations are viewed through scanning ai disc, thus the colored image. Ì reconstructing siüilililililAr- BLUE

GREEN in GREEN Color CIRCUIT TO POWER AMPLIFIER "A By Dr. Herbert E. Ives + OUTPUT REVOLVING COMMUTATOR GREEN FILTER -ARM CONTACT Member of the Technical Staff, Bell Telephone Laboratories SEGMENTS Above: How large CURRENT VARIATIONS IN PHOTO-CELL AN,NEON -ARGON TUBE glass tube screen CIRCUITS may be arranged for background for color television. A host of methods of reproducing c o l o r combining the three basic colors to form the reproduced television images. its BLUE image available but, in so far as the sending or scanning Each tube has was own color filter, the end is concerned, a method was developed which has no tinfoil segments be- counterpart in color photography. The method of "beam ing connected pro- scanning" -used in the first television demonstration*- gressively into cir- has been employed. cuit. RED To apply this method to color television, three sets of photo -electric cells are employed in place of the one set used Graphic curves at before. Each of these sets is provided with color filters right illustrate how made up of sheets of colored gelatine. One set has filters of different colors are -red color which make the cells see things as the transmitted and re- GREEN an orange ceived. When red hypothetical red sensitive nerves of the retina see them; green and blue are another set has yellow -green filters to give the green signal, equally strong, at a -blue filters which perform a RED GREEN WHITE RESULTING and the third set has greenish given instant, the re- PREDOMINATES PREDOMINATES OBSERVED COMPOSITE corresponding function for the blue constituent of vision. AT AT AT <- COLOR sulting color is white. PATTERN The scanning disc and the light source are the same as with If green predomi- RECEIVER RECEIVER RECEIVER the beam scanning arrangement used in monochromatic nates at a certain in- FRACTION OF A television. The only difference is in the photo- electric cells, stant, then that is the SECOND and thanks to the tri- chromatic nature of color vision, it is major color observed TIME only necessary to have three times the number of cells used at the receiver. previously to reproduce all colors. Three series of television signals, one for each set of cells, are generated instead of inverted "U" in a plane in front of the object. In the new one and three channels are used for the transmission of the photo -cell cage twenty -four cells are employed, two with television signals. "blue" filters, eight with "green" filters, and fourteen with The photo -electric cell container, or "cage," has been built "red" filters. These numbers are so chosen with respect to in a somewhat different form from that used in our first the relative sensitiveness of the cells to different colors that demonstration. There three cells were used arranged in an the photo -electric signals are of about equal value for the three colors. The cells are placed in three banks, one bank in Bell Record, June, 1928, page 325. front of and above the position of (Continued on page 474)

www.americanradiohistory.com 402 Science and Invention September, 1929

Risking Lives for Dollars MACK

This series of illustrations shows a plane crack -up which w a s disastrous. In This picture shows Al Wilson the filming of the mo- in the "early days." He was tion picture, "Hell's the first man to actually /Ingels," at Caddo Field, Bill drive a golf ball from Jones was operating the smoke the top of a plane's machines to simulate a ship in flames. wing. He was killed in the crash. Al Wilson, the noted stunt flier, who was piloting, jumped with- his parachute when he saw the hopelessness of the situation and escaped with a broken ankle.

I R stories are very popular among movie fans andd particularly among those who are going "air - minded." But ordinarily there is no thrill in watching an airplane make an ordinary flight, nor do scenes from an airplane make the heart beat faster. It is up to the aviators to provide a thrill. This they can do by any one of a group of sensational ways, but the most sensational one of all is to take out a plane and crack it up in the exact spot designated by the cameraman so that he will be able to film the crash. the audience knows Producers are usually able to filin a "dog" fight, substi- that there is some- tuting models for real planes. Such models are operated by thing missing, and the strings, and a moving cloud panorama is employed to indi- picture leaves no impression cate flight, but when it comes to crack -ups, the model gives upon them. but a poor showing. Even if one could use a "prop" plane, Skill Required- Science Enters ORDINARY flying skill is not the only requisite required to cracking up a plane. Nearly anyone can do that. It is different, however, to crack up a plane in such a position that the cam- eramen will be on the spot where the crack -up is to occur. It is also difficult to produce a different kind of a smash for

The photograph below was taken while "The Air Circus" was being produced. Sometimes the parachute lets down its burden easily, at other times the flier is bumped and dragged with more or less violence. Here a flier just missed a hay stack which would have broken his fall. Note how lie is being carried along.

Courtesy Fox Films Corp.

www.americanradiohistory.com September, 1929 Science and Invention 403

Science and Skill combine in properly crack- UPS ing up a plane without sacrificing life By Joseph H. Kraus

various parts of the film, and, last but not least, to come out alive. Most pilots and stunt fliers engaged in this work figure out their moves to a nicety. They know exactly what they are going to do before they do it, and they have laid plans for practically any difficulty that might arise. The cock- pits of the planes are usually well provided The three illustrations above show photographs from the film with padding. On occasion, the aviator also "Lilac Time," a First National Production, starring manages to place several hand or foot holds in Colleen Moore. Note that in several of the pictures the plane, so that he will not be in top photo thrown out the pilot can be seen. Observe the when the ship smashes. In one case the how the plane is made to dig its wing into the aviator ground. This is also true in the photo im- even went so far (Continued on next page) mediately above.

The last two photographs of the plane in air, and then at the right-the end. Ordi- narily the grim hand of death does not stretch out toward stunt fliers. This disaster prompted an inquiry from the Aero- nantie Bureau of the Department of Commerce.

www.americanradiohistory.com 404 Science and Invention September, 1929 as to tie an an- Crashing vil weighing your plane several hundred Crack ups into a house pounds under (Continued from previous page) or tree makes the front axle a wonderful of the plane, so smash and a that t h e plane marvelous would surely go scene. It thrills over on its back t h e audience, after its nose worries the was made to wife and fam- sink into the ily, and gives soft turf. the aviator $ 1,200.00. Spinning t h e Stunt Fliers plane to earth Receive Little in a crash gives One of the most remarkable photographs is shown above. The pilot may be seen at his the aviator the Money place in this plane, which executed a nose dive near hangars during the filming of Fox same price, Films' "The "hir Circus." but that is the ONE would limit of the V think that the reckless fliers engaged in these breath- big money. And now we come to the lower -paid attractions. taking stunts would receive very high salaries for risking For the sum of $500.00 you must loop the loop with a man their lives the way they do, yet there is perhaps no group on top of the plane, and changing from a plane upside down of persons who risk their lives as often and are paid more to another in mid -air nets you a check for $450.00. Fighting cheaply than these men who gamble with death. Mr. George on top of the wing and being knocked off gives you but M. Atkins, of Monroe, N. Y., has compiled a group of prices $225.00, if you are the fortunate individual that is thrown which the stunt fliers get for their tricks. The maximum off the top of the wing. Doing a double parachute jump salary for any trick is $1,500, but in order to collect this you gives $180.00 ; that is, two men on but one 'chute. Flying must take your plane upside down with a up in the air and blow man hanging on the it up in midair by landing gear adds to firing off a charge of the official account a dynamite. If you can sum of $150.00. A get away by taking to parachute jump nets a parachute and if only $80.00. For fly- you land safely, you ing your plane upside collect; if not, the down and holding on money goes for fu- you get $100.00; neral expenses. Don't changing from one f orget that this is plane to another in maximum salary, midair is worth but many aviators get less $100.00, and changing f o r performing the from a plane to a rail- same stunt. Also, as road train means Mr. Atkins put it, $150.00. "your parachute may But like every other forget to open, and in game, the one of stunt most scenes it is a Here is an illustration of quite a r emarkable crash. This picture was flying is thrilling. long distance to taken in 1927, and starred Milton Sil ls. Note man running to the wreck - Each time the flier earth." age. The clouds are not smoke but dust. (Coned on page 462)

Left: These unusually thrilling action shots were seen in the Russ Farrell aviator subjects, motion -picture versions of the well -known f l y in g stories by Thomson Burtis. Reed Howes is seen here making a sensational leap from a motorcycle to a low -flying airplane. Right: An exchange in mid -air from plane to plane. Courtesy Educational Pietures Courtesy Educational l'ie Ures

www.americanradiohistory.com September, 1929 Science and Invention 405

NEW FILM SOUND TRACKS

STANDARD FILM

The illustration above shows differences in film sizes.

This illustration shows the difference in the size of the screen between that on which the present -day movie is projected in a large show house and the screen used with the new system. The grains of silver on the film are not enlarged to any greater extent than at present. Left-the camera.

Stereoscopic Movies With Color and Voice in the Making By H. Winfield Secor

Details of the camera HALF -SILVERED MIRROR are not available, 1ENS but this gives a clear idea of how an effect of three dimensions is obtained. Images from both lenses are made A to register perfectly LENS on the same film. FILMI Shadow differences are produced.

THE movies took another stride forward recently, when a new photographic and projection system of producing a three -dimensional effect was demonstrated at the R. C. A. Photophone Studio in New York. This motion - picture system was developed by (Continued on page 456) The camera and its developers, P. John Berggren and George K. Spoor.

How three- dimensional effect is produced. Looking at mear finger makes distant finger appear double and vice versa. Look midway between and both fingers appear double.

www.americanradiohistory.com 406 Science and Invention September, 1929

Many Creatures of the Field and Stream Have Mastered the Prin- ciiiles of Gliding

Above is Vampirus (Phyllostoma) spectrum, the bat, which is capable of actual flight. At the left is a flying rodent, Petaurista oral (Pteromys petaurista). The young squirrels are equipped with a membranous fold where the arm joins the body. This fold forms a bridge between the rump and upper arm. Im the matured animal this fold has disappeared, as it would be a disad- \y** vantage. ï/ I 4.. , r ..

By Dr. Ernest Bade Animals that

THE name of Lillienthal will always be closely allied when the creature jumps. With its aid, it is said, the animal to the science of aeronautics, especially motorless can glide 240 feet when it hurls itself from a lofty tree. It flight. That such gliding flights are comparatively is not improbable that the strong and massive tendons which easy to accomplish is attested by the way nature has adapted project from the arm bone into the gliding membrane serve certain typically land and aquatic animals for this action, as the purpose of raising or lowering the fold while in flight. distinguished from flying. Such creatures differ greatly But observations on this point have not, as yet, been made. from the birds, true masters of the air. While the majority At any rate, very little is known about the life history of this of the birds are able to ,fly at will, other animals, with the interesting and unique creature. exception of the bat, must be satisfied with a more or less Far less developed is the gliding membrane of the flying gliding motion through the air, and such a gliding flight is squirrels. Our native species, Glaucomys volans, has a by no means rare in the animal kingdom. peculiar cartilage attached to the base of the hand which is A large number of tree -inhabiting creatures are able to used to spread the fold while gliding. These creatures be- employ it successfully and to utilize this gift as a rapid come exceptionally lively at dusk; their jumps can hardly be means of escape from danger or to capture their prey from followed with the eye. Like a ghost, they hurry from the above. Confidence and sure- footedness in the crowns of height to the depth and quickly reclimb the trunks of the the trees and ease in securing food undoubtedly have been an trees. Southern Asia is profusely provided with such forms important factor in the selection of such dwelling places. and the Sunda Islands are inhabited by more than half a But they could only feel at home after they had, in addition dozen species, the largest attaining a length of about 1% to their climbing and jumping proclivities, surfaces or "air - feet. foils" adapted for gliding, which protect them from missteps Dragons That Fly and sudden falls, enabling them, as it does, to glide grace - fully and uninjured to the ground far below. THE tiny dragon, Draco, of which more than 20 different species are native of the Sunda Isles, have solved Flying Squirrels the problem of gliding flight in an entirely different manner. The usually ridged ribs, movable only in snakes, have been THE necessity and value of such gliding surfaces becomes employed to spread the gliding membrane. In addition to evident in younger animals which have not, as yet, at- this these dragons pump this fold of the skin full of air. At tained the proficiency and agility in climbing of more mature rest, this surface is folded together and placed close to the individuals. It is for this reason that young squirrels pos- body. Such a structure, where part of the ribs fulfill'a dif- sess a peculiar membranous fold where the arm joins the ferent purpose, a purpose for strengthening another struc- body. This fold forms a bridge between upper arm and ture,.is not found in any other animal. rump. In the mature individuals this gliding surface has These little dragons are true arboreal lizards. They are disappeared, for that which is an advantage in youth is a never found upon the ground unless forced to descend when disadvantage in the more mature form. danger threatens them. High in the loftiest crowns is their Of mammals provided with gliding membranes, the ma- abiding place, sunning themselves in these airy heights. In jority belong to the order of the rodents, but certain mar - color these creatures, which are only about 8 inches in length supialia and lemurs are also represented. A lemur, Galeo- with their tail, are exceptionally vivid. Like glittering gems pithecus volitans, from the Sunda Isles, has a fold of skin they float through the air as they hunt their insect food. extending from the neck, taking in the forelegs to the While in flight they cover distances of approximately 60 fingers, and extending along the sides, encircling the hind feet, land lower than the starting place and quickly return, legs and ending at the muscles of the tail. This fold is running up the trunks of the trees. The grotesquely tinted thickly covered with hairs on both of its sides and is spread flying lizards, Ptvchós.00n, of the Malay Archipelago, also

www.americanradiohistory.com September, 1929 Science and Invention 407

The flying dragon, Draco limbriatus, is shown at left in flight. While in flight, the animals are capable of covering distances as great as sixty feet in one glide. Flying fish, Exoccetus (volitans) rubrescens, shown at left below, - have large pectoral fins which form an excellent gliding surface. T h e peculiarly formed tail fins also aid the fish in flight. Flights of approximately 600 feet made by the fish have been observed.

Learned to Fly have web -like structures on each side of their body. This extensible membrane has but little sustaining power, although it does aid materially in extending their jumps. The skeleton of the small dragon, Draco, is Aerial Frogs shown at t he right: The usual IT is peculiar that the region of the large Sunda Islands ridged ribs, is profusely inhabited by numerous gliding creatures movable only in of the most varied form. Even flying frogs are native to snakes, are used this section. Here the toes, which are already provided with to spread t h e a swimming web and suction disks for climbing, can also be gliding m e m - used for gliding. Such a frog; having a length of 2 inches brane. and a width of / of an inch while at rest, has a horizontal surface of approximately 1% square inches, while in flight more than six times this horizontal area is easily covered. On the level this flying frog can cover a distance of 6 feet in one jump, when the abnormally developed webbed feet come into play as gliding surfaces. As soon as the frog is in the air, it brings its body into a characteristic gliding position. The elbow joints of both front legs are tightly bunched against the body and the large webbed feet spread and held in such a position that they are turned outward. The same occurs with the hind legs. At the same time the loosely folded skin of the legs is (Continued on page 461)

A frog which can glide, Rhacoplzorus reinwardti, a native of the Sunda Islands, is shown above. The toes, which are already provided with a swimming web and suction disks for climbing, can also be used for gliding. While at rest, such a frog, two inches long and three -quarters of an inch wide, has a horizontal surface of about one and one -half square inches. In flight more than six times this area is covered.

www.americanradiohistory.com 408 Science and Invention September, 1929

RAIL -BED RENOVATOR: Above is a mechanical device, developed by the Pennsylvania R. R. Co. and the Industrial Brownhoist Co., for automatically renovating track ballast by excavation, removing the dirt, returning the stone to the track and leveling the renovated ballast to standard profile. Ballast can be cleaned at the rate of 1.200 ft. of track per hour. Scientific Progress

AEROCAR : A new type of vehicle, called the Aero- car, invented by Mr. Glenn H. Curtiss, is shown above. It is attached directly to the Latest News power unit, which may be in any type of automobile ca- Various pable of pulling the load. Fields as When drawn by a Ford roadster, the Aerocar will Caught by attain a speed of 55 miles per hour. the Cam- BOULDER DAM: At era's Eye the right is an artist's conception of the Boulder Dam across the Colorado River. It is estimated that eight years' time will be required to finish it. Note size of Washington Monument. SYNTHETIC SUB ESCAPE STONE : T h e photograph at TUBE: The illustra- shows tion at the left shows the left a new a escape tube samples of for submarines. A new composi- member of tion which can the crew is seen leaving it. be used to replace stone in all building construction. T h e Right : How crew material is po- can be transferred rous and nails from one submarine can be readily to another along a driven into it cable connecting the without s p 1 i t- two escape chambers. ting the block. The sailor enters The composi- and closes the lock in tion s t one is the "sub," then lets also waterproof in the sea w a t e r. and is not affect- When chamber is ed by changes in nearly full, he opens temperature. the external gate.

www.americanradiohistory.com September, 1929 Science and Invention 409.

AUTO TUNNEL : The three photos appearing here show views of the Zion -Mount Carmel Highway, in southern Utah, which is nearing completion and will be open to vehicles shortly. It is the longest tunnel outside of a city in the United States. A two -way illuminated bore. 1Y8 miles from portal to portal, runs through an unscaled mountain. The clotted line in the photo below shows course of tunnel. The photograph at the right shows a section of the tunnel, and the view below, to the right, shows the high scaffolds which were erected against the cliff faces during the course of construction.

DIVING SUIT: Miss Jane Daly, who plays in the motion- picture undersea fantasy entitled "The Mysterious Island," is shown here in her copper -plated diving armor, which she wore during the filming of the picture. Although cumbersome, the diving suit permits - free movement in any direction.

AUXILIARY TIRE: A new invention, which should become most popular with car owners, is shown in the photographs and drawing appearing below. Provision is made for a solid rubber tire of smaller diameter than the car DAREDEVIL: Mr. shoe, to he placed on the inside of Kambrinow, German the wheel. When the tire goes flat for daredevil, recently bet any reason, the car settles that he would drive his slightly on that particular side automobile without and the rest of the driving is pneumatic tires on done on the auxiliary tire. wires, which were stretched 100 ft. above the ground. The wires were 1,000 ft. long and the driver won his bet, making a speed of 15 miles per hour. The course was laid in the vicinity of limestone quarries in Berlin, Ger- many. The photograph shown here was made during the perilous trip The drawing above shows clearly the while the driver, show- action of the supplementary tire. By for life running the car up on blocks, which ing a disregard a limb, proceeded to support the solid tire, the need for and jack is eliminated. win his bet.

www.americanradiohistory.com 410 Science and Invention September, 1929 Coal Miner's Job Safer By Alvin F. Harlow

a sixteenth -century writer on the subject, "whether to work in metals is honorable employment for respect- able people or whether it is not de- grading and dishonorable." Not until within the last century - one might almost say within the last half century -have many medieval methods disappeared from the mines, even from those of America. As the workings were driven deeper and wider, and became more complex, and as our demands for speed and greater production goaded operators and men on to greater recklessness, the daily toll of disabling accidents and the record of large and terribly fatal mine disasters began to assume dreadful dimensions. The first moves in the direction of modern safety work in the mining industry were made in the Pennsylvania fl trained rescue crew furnished with the latest equipment about to enter a mine. Note anthracite field in 1869. Industrial modern entrance portal. prophets were arising who hinted that safety was desirable not only for humanitarian reasons but be- AHUMOROUS poem of fifty years ago pictured cause it made for economy and larger production. They Barney Buntline and Billy Bowling, at sea on a were among the earliest heralds of the age of modern busi- stormy night, as thanking their lucky stars that they ness efficiency. were not on shore, where houses were liable to be unroofed There has been more accomplished in the matter of mak- or struck by lightning and burned, or chimney pots blown clown on their heads, but instead they were snug on ship- board and safe from all those dangers. Even so, a miner, a The photograph at thousand feet down in the bowels of the earth, sitting on a the left shows a box of dynamite as he eats his noonday lunch and glances rock dust barrier over a scrap of newspaper, may be supposed to shudder as ready to smooth a he reads the numberless hazards of life on the surface coal dust explosion. -of Below is a view of the whistle of bullets and the crunch of automobiles over the rock dust shelf human bodies in city streets ; of shipwrecks, tornadoes and after the air wave crashing airplanes; of men teetering dizzily on skyscraper h a s passed. The skeletons hundreds of feet in air; of the deadly splash of tendency of c o al great ladles full of molten metal and the dreadful lunge of dust to explode is giant locomotives smashing through coaches full of tortured nullified by the humanity. For mining, though intrinsically a very hazard- rock dust. ous occupation, is now by reason of safety methods, mechanical safeguards and the safety instruction constantly being hammered into the workers, becoming a less dangerous occupation than many an outside job, and would be safer yet if ing life safer and it were not for that ever -weak link in any chain -the comfortable in thoughtless, perverse human individual, who is supposed to the mining indus- remember and obey the rules but doesn't ! try in the past Of course mining isn't the pleasantest of all occupations; fifty years than but it has been bettered enormously since the early days of in t h e previous coal production, some six or seven hundred years ago,, when five hundred. By the job was regarded with so little favor, that Scotch coal far the greater miners had to be chained at their work. When one remem- part of it has bers that no explosives were used in mining then nor for been achieved in several centuries thereafter, and that every foot of the way the last two dec- had to be dug with pick and crowbar and fires built against ades. the rock to crumble it, when one hears from some early After soine writers that the miner was compelled to work (possibly in years of groping gaseous pits) with no better light than the phosphorescent effort on the pa'rt of a few mine owners, it became apparent glow from certain kinds of dried fish, one marvels little that that a great national agency was needed to obtain the best the miner displayed an occasional tendency to run away possible study of the numerous problems. This need- was from the job. brought to public and Congressional attention in very tragic So unpleasant was the ancient and medieval miner's work fashion in 1907 by two of the greatest subterranean disästers that one of the favorite forms of punishment, for whatever in American history -the IIonongah Mine explosion in. West was called crime in those days, was a sentence to labor in Virginia, in which 361 men lost their lives, followed only the mines. It came to be questioned, said Georgius Agricola, thirteen clays later by the explosion at Jacobs Creek,

www.americanradiohistory.com 1929 September, Science and Invention 411

Explosive materials are placed in than Yours! whitewashed niches in the walls. The danger from explo- Workers' lives scientifically pro- sives has been tected and made tolerable greatly reduced. underground

Pennsylvania, in which 239 B elow: Miner men were killed. The United making repair on States Bureau of Mines was established by Congressional railroad system im- act in 1909 with the purpose, not only of conserving human mediately a f t e r life and health in the industry, but also of assisting in curb- trouble occurred. ing the waste from inefficient methods and excessive com- At bottom of page: petition. Example of care- To this Bureau much credit is due for the reforms and lessness - miner improvements of recent years. More recently the National smoking cigarette Safety all and opening pow- Council, sponsored by classes of industry and der can with pick. engineering, has done valuable work along similar lines; All photos courtesy and there are still other agencies-the manufacturers of U. S. Bureau of explosives, for example, whose interest it is to prove that Mines. their products when properly handled are as docile and gentle as any dove. covered to the astonishment of many The first great desideratum in mak- that explosions of gas and dust which, ing life more tolerable underground is because of their dramatic character, that it be made safer. The accidents seemed to the public to be the greatest having the greatest immediate possi- of mine dangers, in reality cause on bilities for danger to men working in an average less than one -fifth of all mines are explosions. These are of the coal -mine fatalities, and in some three kinds : those caused by man's districts a much smaller proportion, own blasting agents, those caused by while in metal mines in general the coal dust and those caused by gases. danger from such things is negligible. The two last named have been respon- By far the greatest percentage of sible for the greatest and most ap- deaths and disablements results from palling of mine disasters, but in a falls of rock, ore or coal from roof or. great number of cases these explosions side of tunnel, with haulage, loading of gas and dust have been set off by and other individual casualties follow- blasts of powder or dynamite or by ing close behind. flames or sparks used for or created But the spectacular disasters in in firing such blasts. which many men were killed at once The first labor of the Bureau of attracted the greatest public attention Mines was the collection of data re and were the problem first attacked by garding accidents. This work had not the new safety engineering. For years proceeded very far when it was dis- the most elaborate precautions were devoted to reducing this danger. After long study it was learned that explosions not only cause fewer fatalities and disablements, but that they were more easily controlled than certain other types of accident which kill or disable only one or two men at a time, but which take a steady toll throughout the year. In recent years the danger from the use of blasting media and from the explosion of the natural elements in the mines had been greatly reduced. In fact, if all operators could be induced to install all the known safeguards and all the workers could be induced to obey all the rules, the danger from explosions would be well nigh eliminated. This may sound extravagant, but it is true. Explosives are not in the habit of blowing up of their own accord nor do coal dust and gases do so. It appeared, therefore, that in the matter of explosions much good might be done by using some protection, some education and some elimination of hazard; but as to guard- ing against falls of material from roof, or against loading and haulage casualties, education must be relied upon; and because of human recklessness and forgetfulness this has proven to be a difficult proposition. It was formerly believed that all the great explosions in mines were caused by gas, or as it was popularly called, fire -damp. That coal dust could explode was for a long time unknown, and when miners began to talk of dust explosions, many authorities scoffed at the idea. But within the last ten or twelve years the explosive quality of bituminous coal dust when mixed with oxygen has been amply proven by the Bureau of Mines, which staged actual dust explosions in its experimental coal mine at Bruceton, Penn- sylvania. That mine, by the way, has been a remarkably useful laboratory. The (Continued on page 468)

www.americanradiohistory.com September, 1929 412 Science and Invention Super- Directional Horn Directs Safe Landing in Fog

The giant dirigible, Graf Zeppelin, flying low over the hangar at Lake - burst. The large horn, which will be used to direct the landing in RntTri,iwig{iexts9;, case of fog, is visible in the fore- will M 1Mi:ßt ground. The sound beacon ir l a r g e 5 C. yr1eY also aid in handling the . . crowds as well as furnish musical programs.

Giant Voice Helps Land ZEP

Details' THE huge horn will be placed on a turn- table, so that the direction of the sound can be changed at will and made to follow the path taken by the dirigible. Two standard auditorium amplifiers will be placed in the hangar. These will provide the necessary volume to enable the horn to be heard over the entire field. When used in conjunction with a phonograph, this equipment will be employed to entertain the crowds. Warnings and instructions can also be given to the sightseers through the medium of the huge horns and associated equipment. Construction THE giant horn consists of a cluster of small -mouthed conical horns, each equipped with a special unit. These A close -up view of the giant horn appears above. An horns are joined to a single mouth, straight sided, and as- excellent conception of the size of this horn can be deter- sembled in a space approximately 8 feet square and 12 feet mined by comparison with the man. long. Should fog make the visibility poor, the Zeppelin will be HEN the giant dirigible, Graf Zeppelin, arrives at signaled to follow the sound beam from the horn. Two horn Lakehurst an easy landing will be assured, even units will be mounted on the hangar. W though the weather is of the worst. The newest It is estimated that no difficulty will be experienced in development in sound communication, made by the Victor reaching as many as 350,000 persons with both messages and Talking Machine Company at Camden, N. J., will be used music through the medium of the giant horns. During to help the Zeppelin to a safe berth on the ground. recent tests individuals in cars as far distant as one mile from the hangar plainly heard the music but were, of course, Super- Directional Horn unable to determine the exact source of the sound. AHUGE horn having super -directional qualities will Cost and Tests enable communication between the ground and the Zeppelin while the ship is still several hundred feet above NAVAL officers are deeply interested in this develop- the field. Naval officers will thus be in a position to advise ment of sound beacons, and the results of the latest the Zeppelin commander as to the best way in which to bring aviation communication system are being watched eagerly. the ship safely into port. Representatives from the Guggenheim Fund will also con- A microphone is being placed in the Navy Communica- duct a number of tests with naval aircraft. tions Department at the Lakehurst hangar and several others Engineers supervising the installation stated that four will be positioned about the field at strategic points. All of five -ton trucks were required to transport the equipment these posts will be connected with the commandant's office from the Camden laboratories. The apparatus is valued by a special telephone system. approximately at $50,000.

www.americanradiohistory.com September, 1929 Science and Invention 413 The Modern Sherlock Holmes "Homicide Kit" Is Part of the Equipment The above illustration shows how a of Present -Day Sleuths bullet is removed from the wall, so as not to destroy any markings which may have been imparted to it as it was pro- pelled through the gun barrel.

THE forerunner of our present -clay scientific detective was undoubtedly that fictional character, Sher- lock Holmes, well known to all. The modern sleuth is aided by science in his investigations, and if he does not go so far as to deduce from a torn shred of cloth that the wearer of the garment was a middle -aged man with a sandy mustache, who walked with a limp and had a large wart on the back of his neck -nevertheless, some of the present -day deductions are nearly as startling. "Homicide Kit" ACTING CAPTAIN DONOVAN and Sergeant McGuire, of the Homicide Division, Police Department, New York City, are the inventors of what has come to be known as a "homicide kit," which is now part of the equip- Various accessories ment homicide five which are included of squads in the boroughs of New York in the police de- City. partment "homi- The case contains a number of tools, such as hammer, cide kit" are shown chisel, screw -driver, pliers, saw and scissors. The accessories above. for securing fingerprints include a special camera, a blower for powder, a brush and a pair of rubber gloves. Various other miscellaneous articles, such as a magnifying glass, pen- cils, tape measure, mirror, flashlight, cord, cheesecloth and test tube, are also provided. Aluminum powder, sprayed upon the Uses of the Kit walls or furniture wit h an electric at the scene of the crime, photos the blower, quickly re- UPON arriving of fingerprints body and surroundings are taken; the detective then veals uses his tape measure and notes the exact position of the body, also taking fingerprints of the deceased. The magnifying glass is used to reveal fingerprints on objects. Next the electric blower is brought into use and aluminum powder sprayed over the walls, floor and possibly large of A mirror and a articles flashlight permit furniture. Fingerprints are thus revealed and are then pho- the detective to in- tographed by means of a special camera, which is placed vestigate inaccess- directly against the wall or other object over the fingerprint. ible nooks and cor- Illumination is provided by small electric bulbs placed in the ners. front of the camera. Where dark objects are to be investi- gated for fingerprints, aluminum (Continued on page 465)

The photographs below show a group of kits used in the five boroughs of New York City and a view of one of the kits with trays removed.

Fingerprints on the walls of a room are photographed with a special camera, illustrated at the right.

www.americanradiohistory.com September, 1929 414 Science and Invention Valuable Time and Labor Savers

Plug This is a new kind of soft rubber: plug. It can be stepped on or struck with a hammer and is not damaged. -

Sink Stopper This device fits into the drain. of the kitchen sink. When it is turned, it stops up the outlet, making the sink a basin, in which the dishes can be washed. In- Owl Clock sert shows close -up of the device. In this clock the rotating eyes tell the time. The time indicated here is 6 :02. Each orbit is marked with radial lines. Four -Way Outlet An outlet for the table top which enables the housewife to plug in four utilities to the lines. It is made in figured bakelite.

Zerometer Don't wait until the winter-sets in before you prepare your car for cold weather. This simple meter tells you instantly the freezing point of the mixture in your radiator.

This shows a close -up view Attachment of the clock -work Iron operates the The photo at bake- which shows This plug, made in colored eyes in the owl clock. the left lite, has a grip for the fingers. The h o w the drink grip moves back dispenser is op- and forth in a erated. ball -like joint.

Electric Hot -Water Bottle Attachment Drink Dispenser type of drink dispenser for fountains. This plug will heat the water in fI new nozzle is pushed into the main- It is made of bakelite. fI pump beneath the When the glass the hot -water bottles and the stream, the cup is filled. tain an even temperature. fountain produces a continuous liquid stream. path of

www.americanradiohistory.com September, 1929 Science and Invention 415 For Your Home

Paint Sprayer By aid of this sprayer, m o d - ern furniture can be easily and quickly dec- orated. Illustra- tion at the right shows the details of the sprayer itself. The tank has a pump and an air - pressure gauge.

Rubber Stamp This new type of stamp permits a perfect impression, regard- less of how the A Dangerous Weapon handle is held. This looks like an automatic pistol, and it is actually filled with The ball joint al- powder, but the powder is for facial use. Mirror and rouge are lows freedom of also contained in the article. No matter how used, it's dangerous. motion of the stamp proper.

Slide Rule !I new slide rule extended. It is equivalent to an 88 -inch rule.

Electric Pen This shows a new type of pen provided with a heated metal point. The heat intensity is regulated by the size of the l a mp connected in series Can Opener with the pen. Gold, Placing this can opener on a silver, and other can and turning metallic foils the key, cuts e an out the top and leaves a smooth be burnt into báke- edge. lite or leather by its aid.

The insert here is a close -up of two pieces of the new solid fuel.

Modernist Furniture Much difficulty is found in painting straight bands on new furniture. Adhesive tape makes an excellent straight -edged stencil. Tape is left in place until paint is dry.- George W. Sutton, Jr. Portable Utensils, Stoves and Solid Fuel At the right are shown a few portable utensils and different styles of stoves which use the new solid fuel. This fuel comes in stick form and produces a greater quantity of heat than alcohol. The flat -iron folds up and in every case the stove fits the utensil to be used with it.

www.americanradiohistory.com and Invention September, 1929 416 Science AVIATION

HELICOPT vention of the helicopter, an ì zontal propelle the others on e

SPEED : The above photograph shows Captain Frank M. Hawks with his Lockheed express monoplane, in which he lowered the coast -to -coast non -stop record. A cowling protects the motor and lends greater speed. Arrows show, air current.

striking illustration of the United States dirigibleNavy's giant ZRS -4, now l Under construction, as it will appear when completed. This huge aircraft will be provided with guns at the bow, the center and stern. These guns are clearly visible in the picture.

be at the .21 LARGEST HANGAR, shown below, is soon to erected WORLD'S and the Statue Municipal Airport at Akron, Ohio. The Washington Monument end to end, could be fitted within the hangar and still leave : Aeronauti- of Liberty, placed AÌRPLANE TERMS carriers, "Saratoga" and "Lexington," the two largest ships are now being explained in room for the airplane 200 feet cal terms The immense hangar will be 1,200 feet long, 360 feet wide and diagram form, as shown above. No. 1 is afloat. square feet. The doors at the longi- high, having an unobstructed floor area of 389,000 the stabilizer, which controls and are operated automatically. The structure No. 2 is the elevator; each end will run on forty wheels tudinal stability; in the world without supporting pillars or posts. No. 3 is the fin and No. 4 is the rudder. is the largest building

_- i/fIIorm í / ;; , ` i;iii//_U1 /`t i e ` ,,i,i"i"i ;. /i %o_ ; .l1 ( -a -/ , iaííí//l%%Ö//%/%/ / /i/ / /%u%-r/_%u%=%.%r-/. )_iiíï itLIA ,y,; :% .a l ' .. n ;"¡Nit

www.americanradiohistory.com September, 1929 Science and Invention 417

AMPHIBIAN: We give three views of a new amphibian, with a speed of Up- To-Date 115 miles per hour. The cabin will hold six persons.

THE PLANE, shown above, is a new monoplane capable of attaining a speed of 95 air miles per hour. The craft is equipped with tires that eliminate the need for shock absorbers.

AVIATION CLASSES : The above view shows students and their instructor studying the various parts of a large biplane, which is part of the equipment of the George Washing- ton High School in Los Angeles, California. This is the first high school to offer classes in aviation to the students.

HELICO PTER: Below is a view of a vertical rising plane of a type which may revolutionize flying and eliminate the need for large landing fields. The skeleton shown is of steel. The new craft will be first tested in a trial STEAM DIRIGI- flight some time during the fall at the Munici- BLE: The photo- in pal Airport Chicago. The inventor and graph above shows a five - his wife are shown inspecting the plane in bladed "blower" propeller hangar, it the army where is now stored. for the steam- driven all - metal dirigible "The City of Glendale." A speed of 100 miles per hour is expected with 40 passengers.

"SHOVEL- NOSE" PLANE: Above is a plane of odd design, driven by a propeller which whirls through an aperture in the large wing. The wing covers the suspended cabin, motor, and landing gear. Due to its construction, the airplane will lift 5% pounds per square foot. The ordinary plane can only lift 2% pounds per square foot. Mr. E. E. McClary of Long Beach, California, is the designer.

www.americanradiohistory.com 1929 418 Science and Invention September, Is a College Education

Helps more after success has been attained W. O'Neil President of the General Tire and Rubber Company

Yes, but lack of it is not necessarily fatal to success Frank Melville, Jr. President of the Melville Shoe Corporation

Few leaders in Amer- depends upon the boy. If he is willing to fight, to ican industry can practice self -denial and to forego immediate rewards in match the romantic interest a better job, he will eventually reach career of Frank Mel- the of doing ville, Jr., president of the top, college trained or no. the Melville Shoe Cor- Now, it seems fairly simple for us to understand that poration. He was born if we would be active in sports, we must exercise our seventy years ago in physical equipment. The body must be groomed for its the old Ninth Ward job ; the nerves, (Continued on page in New York City the son of a schoolmaster father and a cul- particular 454) tured, talented mother. At fifteen he ran away from the Ft. Edward Academy (N. Y.) because, he explains, no one even translated the word education to him. His first job was clerking in a shoe store; but for ten years he drifted from one employ- W. O'Neil is presi- ment to another. He was master of a sailing boat, owner of a dent of one of this bathing concession; he worked in a factory where they made country's largest tire straw hats from canton flannel and he tried his hand at punching and rubber companies, cows in the Dakotas. known as the General It was as a rider for the famous S & G outfit in the Black Tire and Rubber Co., Hills that Mr. Melville first tasted the life of the plains country at Akron, Ohio. Mr. and found it good. Later he drove stage and farmed for a space. O'Neil's opinion on Then Fate upset all of his plans. Returning East to spend Christ- the value of a college mas with his parents, he became engaged, and with the announce- education in business ment of his troth, all idea of again going West left him. He is interesting because went back to selling shoes; perhaps, he told himself, it was a good it presents the subject business if one stuck to it long enough! from the viewpoint of His idea of mass production -and chain distribution -of low a man at the head of priced good shoes came during a visit to the cutting room of a' a large business enter- New England shoe factory. He saw shelf after shelf crowded prise. with rolls of leather- scraps. There was imitation alligator and real; kangaroo and calf and vici kid. These were the left -ovens, he was told. "Supposing," said he, turning to the manufacturer, By W. O'NEIL "that I gave you an order for all the shoes of one style you could make for one week, and on the following week I gave you a simi- P r e s i d e n t lar order, to be followed out week after week. What saving General Tire and would it mean in manufacturer "It would mean a tremendous saving," the factory man said Rubber Co., finally. Akron, Ohio. "All right then," said Mr. Melville. "I'll bring you the orders, you make the shoes." THE value of a college education is a hard thing to Since that day his career has been one of steadily mounting measure by any mathematical calculation. It is some- responsibility in the shoe retailing field. In 1906 he lead eight like the benefits of a spring training trip modern stores; in 1920, nineteen. Today there are eleven great thing debating factories making shoes for his 430 Thom McAn, Rival and John for a baseball team. The spring training trip cannot Ward stores in 222 cities. make a baseball player out of a dub but it does seem to help Babe Ruth. The analogy of the baseball training By FRANK MELVILLE, JR. trip is not exactly paralleled, since this training involves from which President of the Melville Shoe Corporation the actual practice in the business of baseball they turn immediately to the full swing of baseball ALMOST every boy starts out with a burning am- activity. With a college education, however, the training bition to win fame in some particular field. Usu- is general and they do not step immediately into the full ally he wants to be a soldier, a sailor or an swing of any activity and whatever business activity they

engineer 'neath tropical skies. . My own case was the step into is going to be entirely different from the train- exception; when I ran away from school at fifteen, my ing they have gone through. motivation was not a consuming impatience to encounter The field of business is a university itself. There are romance and adventure ; rather it was because I never no rules and theories laid down as accurately as those had had the word education translated to me in its in mathematics text -books. Thus we often find that a simple, human values. man who has been very good as a student while all the So I can state unreservedly that I believe a college rules and regulations were exact and laid down for him education is worth while ; at the same time I do not be- in book does not seem to be able to continue his educa- lieve the lack of it is necessarily fatal to success. It all tion in the field of business. He sometimes doesn't seem

www.americanradiohistory.com September, 1929 Science and Invention 419 Worth While?

Desirable, but not necessary Edwin Franko Goldman Conductor, Musician, Composer

That depends on the kind of college education -- -Prof. T. N. Carver Professor of Economics, Harvard

able to grasp the more or less indefinite and even more Professor Thomas necessary principles of ordinary business life. Nixon Carver was I do not think that a college education born on March 25, to the average 1865. He has an B.B. man of business has very much to do with his initial suc- degree from the Uni- cess but the country is going to be better off and the suc- versity of Southern cessful individual happier if he possesses an education California, a Ph.D. and a knowledge of the things outside of his line from Cornell and own LL.D. from Oberlin. of business. A knowledge on (Continued page 454) He was a professor of economics at Oberlin College from 1894 to 1900 and since then at Harvard, where he still is professor of Edwin Franko Gold- political economy. He is a profuse writer on economic subjects man was born on Jan- and was at one time adviser in agricultural economies to the U.S. uary 1, 1878, in Louis- Department of Bgriculture. ville, Kentucky. He began the study of the cornet at eight years By PROFESSOR THOMAS NIXON CARVER of age, and at four- Professor of Political Economy, Harvard teen was awarded a free scholarship at the THERE is no reason for believing that a college edu- National Conserva- cation, as such, is either a help or a hindrance in tory of Music of New business. It all depends upon the kind York. Bt the age of of a college edu- seventeen he was a cation one has. A college education pursued mainly for cornetist in the Metro- the purpose of breaking intò good society, of acquiring politan Opera House expensive tastes, or being able to speak disparagingly of Orchestra, where he the bourgeoise, the Babbits or the middle classes, is remained ten years. In 1918 he started to probably a hindrance in any honest career. A college give band concerts to education pursued exclusively for the purpose of per- audiences o f over sonal enjoyment, of 2esthetic cultivation, or of self - 20,000 people, and his expression, while having a peculiar and sufficient value band concerts on the its "Mall" in Central of own, is probably neither a help nor a hindrance in Park and the "Green" business. But a college education pursued for the pur- at Columbia Univer- pose of fitting oneself into the world of which one is a sity are well known. part and of training one's powers for participation in He has been a guest productive work the is is conductor in five New whatever of world doing cer- York theatres, has tainly more often a help than a hindrance. been honored by the state in recognition of services rendered to Of course we are all familiar with the facility with the people. He is a composer of note. which round pegs get into square holes and square pegs in round holes. A college education is no insurance By EDWIN FRANKO GOLDMAN against that error. To train oneself for work for which Musician, Conductor, Composer one is by nature unfitted may be disastrous. On the other hand, a college education does not increase the AS to just how necessary a college education is, I frequency of that error. In fact it may be supposed to should say depends entirely upon the individual in- diminish that frequency because, if for no other reason, volved. I do not believe that a college education is essen- it somewhat delays the choice of a career, giving the tial for success in business. young man a longer time to think about the problem, I should say that a college education is always a desir- and a somewhat wider outlook on life before the choice able thing to have, but not a necessity, or perhaps not is made. even a help in seven- eighths of the mercantile pursuits. ,I order to be of use in a business career a college To my mind, college does not always educate, but life's education does not have to be definitely vocational, school of experience does, and only those who are awake though a vocational purpose has a legitimate place in to the opportunities offered and ready to grasp them, every plan for a college education. It need not be a make a success of their careers. selfish purpose. The world needs trained men in many There is no reason why a college graduate should not fields. To train oneself for some of these fields is less achieve success in business, but, what is needed more in selfish than to seek an education without regard to the business than book knowledge (Continued on page 454) needs of the world or to any useful (Cont. on page 454)

www.americanradiohistory.com September, 1929 420 Science and Invention

INSTRUMENT BOARD WIND DRIVEN GENERATOR RUDDER photograph above ta CYLINDER V WATERC OLED WING TANKS FOR RADIO The HISPANO SUIZA / shows the "Yellow Bird," 150 GALS. and the illustration at the INDUCTOR right shows the internal COMP SS construction of this same plane, which took Cap- tain Armeno Lotti, Jr., the sponsor and co- pilot, with Jean Assollant, Rene Le- fevre and a stowaway, OIL TANK ELEVATOR Arthur Schreiber, across 50 GALS j' STORAGE the ocean to Spain. BULK HEAD TAIL SKID. RETRACTABLE OBSERVATION RADIATOR HATCH

Left: The route taken by the "Yellow Bird," showing where the plane was reported as having been sighted. This plane kept in communication with ships along the route. It was finally forced to land at Santander, Spain.

Smashing Aviation Records Two Trans- Atlantic Flights, Trans -Continental Speed Record and New Refueling Record Made and Smashed a Week Later

Paris Flight to land in Los Angeles on June 29th, after a total elapsed time 55 minutes and 47 8 o'clock on June 15th, 5 of 43 hours, P. M., New York, seconds. His flight east was A Eastern standard time, accomplished in 17 hours, 38 the French airmen, Jean Assol- minutes and 16 3 -5th seconds. lant, Rene Lefevre and Ar- His flight west was made in 19 mendo Lotti, together with a hours, 10 minutes and 32 sec- stowaway, Arthur Schreiber, onds. His average speed on landed on the beach near San- the east-west flight was 152 tander, Spain, 29 hours and 52 miles per hour. By this flight minutes after the start from Captain Hawks broke all pre- Old Orchard beach, Maine. vious records for the trans- Two- thirds of the way the fliers continental journey. had to contend with storms. They were further hampered New Endurance Record by the extra man who had crept into the plane just before BYRON K. INEWCOMB it took off from Old Orchard. and Roy L. Mitchell set a Forced to swing south of the new refueling duration flight steamship lanes because of on July 6th of 174 hours and storms, their flight covered a 59 seconds. This was done at distance of 3,128 miles. They Cleveland in a plane appropri- then took two hops before they ately named The City of Cleve- reached Paris, which was their land. By this r e c o r d they destination. passed the former record set by James Kelly and Reginald New Trans -Continental Robbins at Fort Worth, Texas, Record Càptain Frank Hawks standing beside the plane in which only a short time ago. When he made a new trans -continental record. refueling, the gasoline is deliv- ON the morning of June 27th Captain Frank Hawks left ered to the endurance plane at the rate of a gallon a second. Mines Field, Los Angeles, California, traveled to At the time of going to press the American monoplane Roosevelt Field, Long Island, and again left Roosevelt Field Pathfinder, en route from Old (Continued on page 456)

www.americanradiohistory.com September, 1929 Science and Invention 421 Hoene Movies How the Movie Can Use This shows how Amateur Maker night flare is Smoke and Fire to Make Unusual Scenes arranged in' front of reflector,tin all and Titles for His Films mounted on stake driven By Don Bennett into the ground. Figs. 1 and lA. To take successful pictures of a large area, many flares and reflectors are needed, an expensive proposition unless the event warrants it. Usually manufactured by the same company is another movie- maker's aid, the opposite in effect of the flare, the smoke-pot, so- called because of its shape. Whereas the flare brightens up everything, the smoke -pot darkens it, laying down a heavy black smoke that gives the effect of burning buildings - buildings can burn in this way for 365 days a year without harm. Smoke -pots offer the amateur many opportunities for tricks. The smoke is so thick that it obscures everything before the lens. Under its curtain sub- stitutions can be made Showing how to place night flare in front that produce of reflector and also how to use a second either novel or comic effects. Let's reflector to kill shadows on the faces, etc. work out a scenario for a little episode and see what will happen. Of course Fire and Smoke careful editing is necessary in working the news -reel out any trick, so that the lapses are not AVE you ever seen seen on the pictures made at Lake George screen. resorts show- Down the road comes a flivver with H and other winter the hero and heroine. They on the ice at night? must be ing the skaters eloping, for they keep looking back as Have you ever wondered how they are i f watching pursuers. They approach you even light a small a made, when can't fork in the (Continued on page 472) room successfully without several high - powered lamps? This night work out -of -doors is made possible by the use of flares, sticks of an especially prepared compound containing magnesium powder that burns slowly, producing an intense white light. These flares are furnished, ready to use, in a cardboard tube with a socket for mounting. A stick is inserted in the hollow tube to support the flare at the required height and a piece of bright tin is tacked to the stick to act as a reflector (see Fig. 1). The top is torn open and a fuse is revealed which, when lighted, ignites a slow- burning yellow composition containing the magnesium mixture. Magnesium flares are furnished in sizes according to the time they will Novel effect by placing flare on far side of burn. The smallest burns half a min- camp -fire. Note the reflector. Fig. 2. ute and from that, in half -minute steps, the time for the flares increases up to four minutes. One flare provides suffi- BLACK CURTAIN -of- WIRE ON WHICH LETTERS ARE cient light for a small group out HUNG BLACK' FLAT" doors, if a reflector is used on the flare and an additional reflector is placed to one side to kill shadows on the features (Fig. 1 -A). A novel effect is secured by placing a LAMP--,N ¿._LAMP flare beside a camp -fire on the side away from the camera, sunk in a small pot, so `- CAMERA not reach lens Smoke -pots lend themselves nicely to the that it does the (Fig. 2). making of fancy or mystic titles. Here a One flare used in this manner will pro- Top view of setting for making "smoke' wood- sprite emerges from the smoke and vide enough illumination for five or six title, illustrated above at right. Letters are hangs up the letters, òne by one, which persons. hung on wire indicated. Fig. 4. eventually form the complete title. Fig. 3.

www.americanradiohistory.com 422 Science and Invention September, 1929 The Truth About Gasoline Savers

Revealed By George A Luers, Automotive other devices in the carburetor which are there to Illustration A, above, shows a Engineer compensate for this great change in air speed; how- carburetor of a moderate- priced these are and none can is ever, none of perfect compen- car. The throttle stop screw sate precisely or to the greatest advantage. shown at A, the idling adjustment and the filter plug at C. at B, Gasoline Economizers

MAINLY the inventor starts in to work out the diffi- CARBURETORS culties of changing the imperfect mixture, which are not perfect, goes through the carburetor, which fact ac- into a more perfect mixture counts for the adjust- AIR before it reaches the cylin- ments provided by the INTAKE ders. Where the invention manufacturers f o r me- PENINGS has been worked out to the tering the gasoline, the extent that it has proven a also the heat. WHEN THE r air and DIAPHRAGM means to give better carbure- ever owner is IS Almost y j DOWN HOLES tion and do this with less satisfied if he can set the j , REGISTER fuel, it becomes a marketable carburetor so that the invention and is made avail- engine hits on all cylin- lí able to the public. ders at all speeds. III dt1 INTAKE Illustration E, above, shows Fix Even running and the MANIFOLD mileage from the completely automatic device, best which dilutes gas mixture is a much -MANIFOLD]INTAKE the fuel burned and adds moisture according to sought and desired com- ON CAR WHIRLWIND GAS SAVER the needs of the engine. bination, but even the Illustration B, above, shows the service -station a t t en d- working principles of a gas saver. )ftUTOMATIC AIR ants cannot adjust the INTAKE carburetor to do both. The mechanic may adjust for mileage, and you will find the car limping along at low speeds. SCREEN If he adjusts to give even running without skipping, you MIXER find your gasoline bill mounting. Much time and money have been spent by individuals, in attempts to correct the faults in carburetors. Inventions of merit have been made, which inventions improve the operating conditions of the engine and at the same time provide III mileage from the gasoline. for much increased CARBURETOR A brief description Man- of the operation of a CONNECTION TO GENERATOR The J. B. Stransky carburetor in a mod- ufacturing Co. make the in erate- priced car w i l l MFÓ The gasoline saver made by the device shown above of Whirlwind Manufacturing Co. illustration C. This is a show the difficulty manifold attachment, but setting the adjustments is shown above in illustration &NO(I NDTOnjNTAKEI' F. This device is fastened be- with valves and adjust- to give high mileage. AIR VALVE ''¡ tween the flanges of the intake ments for individual In the carburetor at il- 114(CG, manifold and the carburetor. fittings. lustration A the a i r ELECTRICAL HEATER passes through the inlet INSIDE CONNECTION-TO RADIATOR Gasoline economizers, featuring special methods but with of the carburetor, OVERFLOW. the same ultimate aim of gasoline economy, are available to across a nozzle in Drawing D, above, shows the product drivers of various makes of cars. Some of these are priced which there is gasoline. of the Electro Gas Saver Manufac- very moderately, while others, due to their more extensive The gasoline is held at turers. and exacting details of manufacture, are correspondingly a specific level through higher priced. means of a chamber and a float. Illustration B is given to show the working principles of When the engine is running slow or is being started, the one of the inexpensive types of gas savers. This device Pistons pull air through at a very low speed. Not having screws into the intake manifold, above the carburetor. In much capacity to pick up gasoline, this nozzle must be opened this device there is a diaphragm, operated by the suction of up quite wide, in order that sufficient gasoline will be picked the engine pistons. At low speed the diaphragm is stiff up and carried into the cylinders. enough to resist movement. At high speed the diaphragm When the engine is operating at a high speed, the piston is moved, causing a hole in the attached tube to register with suction is great. If the nozzle is not immediately closed, the an opening in the manifold pipe. As a result a stream of gasoline is fed in at an excessive rate. Of course there are cool air is brought into the (Continued on page 456)

www.americanradiohistory.com September. 1929 Science and Invention 423 Motor Hints Conducted by George A. Luers Practical Ideas for Autoists

DO YOU KNOW -when the en- CO gine stops suddenly it is due to one of three causes most frequently? These are lack of fuel, loose wires or a broken mechanical part. for ì¡111111pil'1.\.\ Test iÍle:'i0 fuel at the carburetor. Examine for 'Ivrea1Glarelil%Ia loose wires at battery, plugs, switch and at coil. For broken mechanical parts, determine if the rotor in the distributor turns. If the motor cannot be turned by hand, a piston or bearing may be seized.

Home -made Rim Spreader Adjusting Breaker Points AWOODEN rim spreader which can be readily duplicated is shown in the above illustration, where 1 is the joint of rim ; 2, side view of tool ; 3, Tool Pockets ends of iron ; 4, hinge. The two pieces of wood are 2" x 4" in cross- section, ADDITIONAL tool pockets can be and an ordinary strap hinge fastens the fitted to the automobile, as shown short member to the handle. Pieces of in the above illustration, where 1 indi- iron are placed across the ends to grip cates the tool compartment; 2, the the rim. The extended length will vary pocket made of rubberized cloth; 3, hole according to tire size. cut through facing inside body ; 4, wire staples holding bag to facing. The pockets are made by cutting an opening 6" x 4" in the lining inside the car. In- side of these holes are fitted bag -shaped Testing Car Wiring pockets made from heavy material. The pockets are secured with small steel staples, often used in clipping letters and papers together. Compartments so located can be used for storing tools used most frequently, the grease gun and other articles which could not be THE breaker con - kept in. the usual fancy door pockets. tact points require attention each Care of Fan Belt 1,000 miles, and the gap between them Pr HE illustration below should be equal to shows at 1, the fan ; at .02 inch. It is advis- 2, the belt ; 3, generator ; 4, able that the points belt drive. The fan belt be removed and should be kept free from dressed clown flat on grease and adjusted an oil stone. To ad- tightly at all times. Once just the eontact the belt becomes oily, it points, proceed as should be changed. Wipe follows : Lift off the off all grease from pulleys distributor cap and remove rotor. Turn engine slowly with crank until the breaker arm rests on one of the six high points of the cam. The points are then removed and finished ONE of the simplest aids in testing smoothly. Replace the electrical circuits áf a car is the points and ad- an ordinary buzzer of the 6 -volt type. and install new just the gap. The il- By means of this, the lead to each part, belt. Clean old lustration shows at coil, lamps, stop -light and horn can be belt with rag 1, oil stone ; 2, con- safely tested prior to connecting. In moist with gaso- tact points ; 3, cam; the illustration, 1 is the buzzer ; 2, small line and pack 4, distributor; 5, battery clips; 3, test leads; 4 is the dis- away in box of thickness gauge; 6, tributor, the circuit of which is under sawdust as at 5. spacing. test; 5, test lead, and 6, buzzer.

www.americanradiohistory.com 424 Science and Invention September, 1929

WRITTEN LIGHTLY WITH SLATE PENCIL

- - -.:'t =:iv=-

ASSISTANT MIND- READER

Large audiences throughout this country have been mystified by amazement of the spectators, the drawings upon them are found this trick, originated by the writer. At present, various so- called to be identical. Secret: The slate handed to the volunteer is "dealers in magic" are charging fabulous prices for the secret. apparently clean, yet upon close examination one will find a mes- Effect: The mind reader exhibits two clean slates. One of them sage lightly written with slate pencil. It reads, "Kindly draw is handed to a spectator with the instruction to go to the far side this picture and we both will get a good laugh." Thus, if you of the hall and draw any picture he desires with the chalk with are clever enough to pick the right assistant, he will do as the which he is provided. While doing this, the "mental marvel" message indicated. Both he and the magician will find much sketches a picture upon the duplicate slate. When the spectator amusement in the thunderous applause, and the assistant will returns, both slates are held up for examination, and to the not acknowledge his complicity to any except closest friends.

NUMBER 73 ti1AGIC OF A SERIES Materializations Demon Swordsmanship The Talkative Coin HIS is an interesting spirit effect. IN previous articles in this series, I The wizard is stripped of his have mentioned "talking" coins T clothing and examined to prove wherein the coin beneath the cover is that no apparatus is concealed about his the one manipulated. The effect : A coin person. After dressing in a borrowed is examined, marked and dropped into a suit if desired, he is securely bound in a glass which is placed by the spectator on is then seated position to an ordinary office BACK an end table. A handkerchief chair. The lights are extinguished and borrowed and used to cover the glass. a few moments thereafter a small Any questions now asked are answered sphere of a ghostly green color becomes by clinks of the coin. At any moment visible, gradually grows larger and takes the coin can be examined. The secret :

SAME DE AS CARP \\111111/11/

COIN

HANDKERCHIEF With the aid of a card, on the back of which a piece of cloth has been pasted, the STAND magician can catch a card in air on the muTmlt;,,' point of a previously examined sword. THREAD THREAD ELASTIC ALL kinds of mechanical swords have _^ 7ß,..w been constructed for catching a BAND SMALL - \ previously selected card in midair, but in which the sword ... HOLE I °,' this is the first trick can be passed for examination before COIN The effect is and after presentation. / / /1111 briefly as follows : A card is selected Even though the magician has been thor- from a pack, shuffled into the pack again f1 duplicate coin in a glass, concealed in oughly searched and securely bound, he and the spectator, upon request, tosses the performer's hip pocket, produces the can materialize a ghost in a dark -room the entire deck into the air. The wizard sound which spectators believe comes from séance. thrusts the point of the sword among a glass and coin on the table. the falling cards and mysteriously on the form of a face. After a few catches the chosen card. Secret : The All of the paraphernalia on the table is minutes, the sphere again shrinks and card is forced. A duplicate has been absolutely innocent of deception. The disappears. The secret lies in the fact prepared by pasting a piece of cloth of performer has prepared himself by plac- that a small toy balloon painted with a the same color and design as the carpet ing a duplicate tumbler in his hip pocket. non- poisonous luminous paint was con- upon the back. When the card is faced This contains a coin attached to a thin cealed in the mouth of the performer; down on the carpet, it is quite invisible. thread which runs down his sleeve and the balloon, on being blown up, pro- The magician pushes the sword point is fastened at the vest. By moving the duces the materialization. The face into the card on the floor and then string the duplicate coin in the pocket is should be artistically finished. brings this up among those in the air. made to produce the sound.

www.americanradiohistory.com September, 1929 Science and Invention 425

Fig. 3 -When the car starts, the scale registers the Fig. 4-As the car rushes up the grade, the scale not mal weight of the man or 175 pounds. reads 250 pounds. The weight is now greatest.

How a ROLLER COASTER Demonstrates Relativity By Donald H. HE characters in this trialogue Menzel, Ph. D. of gravity is only an illusion, due to are a Relativist, a Physicist, and the fact that an object is made to T a Layman; the latter being a deviate from the path it would natu- mere dabbler in the theory. To all rally take if nothing disturbed its appearances they are bent upon pleas- motion. ure, for they are entering an amuse- R.- That's about right. ment park, where the din of merri- P. -I'm not satisfied with your call- ment, the cries of the barker and the ing gravitation an illusion. It seems gay music of the merry -go -round are very real to me. heard. Strange occupation for men R. -In what way ? of science? We shall see. The rela- P. -Well, I should think that the tivist carries a large suitcase, to what movement of an object is caused by purpose will soon be made apparent. some force acting upon it. In the following, for sake of brevity, R. -How will you measure the much of the irrelevant conversation force? has been omitted: Fig. 5 -When the car is at A, the curved P. -One of the most common means Relativist (paying for the tickets) path develops a centrifugal force that is by weighing the object. My - treat, boys. I brought you here throws the man against the scale. At B the R. -I think you are reasoning in a on this wild goose chase for the ex- f orce is upward. circle. The object moves when you press purpose of demonstrating to weigh it, causing a pointer to move you some of the more interesting truths of Relativity. also. Are you not guilty of saying this, "A force, acting on Chorus- Relativity ? a body, produces motion. The presence of a force is de- R. -Yes. Both of you, particularly my friend the Lay- tected by the tendency of the body to move." man, are always insisting that Relativity never comes within P. -That does sound a _little shaky, I'll admit. Perhaps I our experience. I'm going to prove that you're wrong. can fix it up. The object does not have to move. I could Physicist- There's a dip- the -dips (roller -coaster). I'll weigh it on scales rather than a spring balance. (Fig. 1.) take a chance that gravitation will hold the car to the tracks. R. -No, that is still unsatisfactory. In that case you are Layman -If I remember correctly, you claim that the force merely balancing the tendency (Continued on page 466)

Fig. 2-The earth seems to Fig. 1 -The pull of gravity on weight A attract the weight with a is equal to that on weight B. Conse- force of one pound. It is that Fig. 6 -The "world lines" of a falling quently the tendency of the pointer to force we have called gravi- monkey -wrench are shown above. The move in one direction is compensated by tation. However, gravita- track of a body through space -time is a line its tendency to move in the other. tion is as mysterious as ever. called a "world line" or geodesic.

www.americanradiohistory.com and Invention September, 1929 426 Science Experiments with Little-Known Chemicals

By Dr. Ernest Bade

Acetamide can also be made by refluxing a To acetamide in a large flask add bromine mixture of dry ammonium acetate and and shake. Then add a solution of potas- glacial acetic acid. sium hydroxide to decolonize the solution. shaking occasionally, the liquid will The Amides and Amines appear homogeneous. As soon as the described as liquid is uniform and does not separate THE amides may be slowly from ammonia, NH3, in into two layers, it is distilled derived and wide air condenser. which the hydrogen has been partly with a long acid radi- As soon as the vapors in the flask or entirely replaced by organic the re- are prepared by the action reach a temperature of 170° C., cals. They and another substi- of ammonia on the acid chlorides, an- ceiver is removed The amines, on tuted. Save this fraction and continue hydrides or the esters. aceta- hand, may be considered as until all has come over. If the the other it distills in the coming from ammonia (NH3), one or mide crystallizes as hydrogen atoms being re- air condenser, heat the condenser and more of the into the replaced by an alkyl group. Both of the acetamide will run C. and boils at these groups, the amides and the ceiver. It melts at 82° secondary and 222° C. If it does not crystallize at amines, give primary, Remove compounds, each group having once, let its stand over night. tertiary on filter paper. its own distinct reactions and thus its the crystals and dry distinguishing chemical differences. The remaining liquid may be again a primary amide, is When the mixture of ethyl acetate and am- distilled and the higher boiling frac- Acetamide, it is distilled slowly with its hydroxyl radical monia is homogeneous, tion saved for another crop of crystals. acetic acid with a small flame, using an air condenser. acetamide removed and the amido group (NH3) Another way to prepare A secondary amide is is by refluxing a mixture of dry am- in its place. more gla- formed when a primary amide and an monium acetate and a little react, thus replacing cial acetic acid. After boiling for acid anhydride with an air another hydrogen, while the tertiary about four hours, distill is formed entirely differ- condenser as mentioned above. amide, which acetamide rather ently, is prepared by the reaction of an Dry the crystals of nitrile, all the three quickly, for they are deliquescent, that anhydride on a from the air hydrogens of the NH3 group being re- is, they absorb moisture acid radicals. and liquefy. placed by the of the Methyl amine is a primary amine of A characteristic reaction lowest sort. It is am- amides is the formation of the acid by the simplest or Acetamide monia (NH3), with one hydrogen reacting with nitrous acid. atom removed and a methyl group sub- gives acetic acid. The secondary amine has two The amines form a group of com- stituted. exceptionally inter- of the hydrogen atoms of ammonia pounds which are for two alkyl radicals, while esting, although not readily prepared substituted means. It is with their aid the tertiary form has lost all of its by simple using alkyl that one can pass from one member of three hydrogen atoms, to in its place. The preparation a homologous series of a compound radicals is a fascinating of these amines is usually difficult in the next. This, truly, laboratory, although some study, especially in this age where all the smaller are produced from of the simpler ones may be prepared. sorts of chemicals from the so- called waste. Take wood alcohol. Since the amine is prepared dis- is first made. The reac- This compound of the destructive amide, acetamide (as well as other tions are simple and just require time. tillation of wood volumes, say 40 c.c. of substances) can be converted to grain Mix equal Naturally the method is not a ethyl acetate and 40 c.c. of strong am- by alcohol. Collect the gas of methyl amine passing commercial process, but since similar vmonia. water, in a flask. Stopper loosely through a condenser and into an inverted two layers vigorously. in a solution of equal vol- reactions in the building up of com- and shake the funnel placed page 464) After a lapse of two or three days, umes of hydrochloric acid and water. pounds is (Continued on

www.americanradiohistory.com September, 1929 Science and Invention 427 Which Articles Do YOU Like Best in Science and Invention? Be Sure to Vote on the Ballot Below Your Particular Choice of Articles FROM time to time the editors make a survey naturally be guided as far as possible by the final of SCIENCE AND INVENTION readers' opinions as results obtained in computing the number of votes to their likes and dislikes. Here is your chance cast pro and con for the various subjects here listed. to vote for more or less of the various classes of If you do not wish to mutilate your magazine, you articles which appear in SCIENCE AND INVENTION. may copy this list either in pen and ink or else have As the editors and publishers of SCIENCE AND IN- it typewritten, and mail it to the Ballot Editor, VENTION aim to please their readers, they will Science and Invention, 381 Fourth Ave., N. Y. City.

MORE LESS MORE LESS Physics Magic Experimental Chemistry and Electricity Scientific Fiction Scientific Problems and Puzzles Automotive How to Make It Botany Editorial Wood Working Construction Articles Wood Turning What Our Readers Think Patent Advice Aviation- General News Book Review Airplane Construction Articles Home Movies Glider Construction Articles Home -Made Furniture Astronomy Agriculture Oracle Medical Shop Mechanics Spiritualism Exposés Finance Radio -New Sets and General Articles Articles Radio Set Construction Hobbies of Famous Men Exposés Interviews With Inventors Motor Hints "Perpetual Motion" Articles Latest Patents Are you a subscriber? Geology Newsstand buyer? Biology What other subjects would you like? Naval Advances Model Department Radio Oracle New Radio Devices Wrinkles, Recipes and Formulas

Making Professional Movie Tides at Small Cost

HOSE who desire neat looking titles for their home - leum or type may be used on a linoleum -block printed back- produced movies, and yet do not feel skilled enough ground. In the latter case, one or more good designs may to attempt hand lettering, will find a small press and be used over and over again, with change of title on each. outfit a great help. A small machine, which may be pur- Making your own Christmas or birthday cards from linoleum chased together with the type, ink etc., for around $18.00 blocks printed in anywhere from two to. seven or eight col- complete, will answer every purpose. Black type can be ors, is much in vogue nowadays, and this may also be done printed on white cards or the reverse -white characters with the same small press. may be used on black cards. Most amateurs find printing in The owner of a small printing outfit for movie titling will black on white cards the most satisfactory. find it very convenient to print his or her own personal sta- If artistic backgrounds for the titles tionery, cards, and other similar work. are available (these can often be cut Bookplate designs in linoleum may be from magazines) the printing can be also made, and for those who want to done right on the background. There put a little more money into the hobby, are no limits to the possibilities and pen -and -ink sketches may be made, the first expense is practically the zinc cuts produced from them by the only expense, except for the trifling company furnishing the press, and cost of the cardboard. Handsome printing can be done from the cut. poster backgound effects may be ob- Just as in the case of a linoleum -block tained by cutting designs in ordi- title background, several good pen - nary floor linoleum, mounting the and-ink or painted backgrounds may be linoleum on a wood block and printing developed, and these may be made into from the block in the press. The The amateur movie p roducer will find this cuts and printed with your press. The words may be either cut in the lino- printing press invali cable for title work. makers carry quite a variety of type.

www.americanradiohistory.com 428 Science and Invention September, 1929 Building a Sport Plane

PART II The completed sport biplane is shown above in flight. It will attain a speed (Conclusion) of 100 miles an hour when powered by a 30- horsepower motor.

BY looking at the drawings, if you are somewhat famil- Dependent upon what type of engine you elect to fit on iar with airplane controls, you will see that the stand- your sport plane, the matter of the engine mounting frame ard control as used in all the Army planes, is here at the front of the plane will vary. The steel plate mounting utilized. The so- called "joy stick," as will be seen from the shown in the drawings here is for the Anzani three -cylinder drawings, is pushed forward or backward in order to raise 30 -35 h.p. motor. This engine mounting plate is made from or lower the horizontal rudders which cause the tail to rise No. 12 gauge sheeet steel, and the very important point to or fall, as the case may be. By moving the joy stick side- be watched here is that this engine mounting plate is rigidly wise, the outboard ailerons are moved up and down for secured to the fuselage. This feature is taken care of by turning and banking. The vertical rudder of use in turning means of turn buckles and the / -inch stranded steel cables, and banking is moved sidewise as required by means of the as drawings clearly show. two vertical rudder wires running back through the fuselage It is practically impossible for an amateur to make a sat- from the foot control lever, which can be seen in dotted isfactory propeller, and so this is to be purchased. It can lines in the top view of the airplane. be obtained from various airplane companies or. from the The fuselage or body of this designers and builders of this - sport plane is made up of sport plane. The wheels of strips of wood, such as spruce, the landing gear are fitted with and after being built to the SO great has been the interest pneumatic tires, and the land- proper shape, is covered with in air- ing gear is made doubly resili- shown by our readers diame- airplane linen, which can then plane construction articles and so ent by means of / -inch be given several coats of ni- ter rubber band, several turns trate dope and then Val spar. excellent is the design of the of which are placed around the many of the accidents axle and the landing gear V A great Lincoln sport plane which orig- indi- which have occurred in flying in the July and frames, as the drawings airplanes has been due to the inally appeared cate. The tail skid, as will be has a wing breaking off, especially August, 1926, issues of this maga- seen, is adjustable, and when making a turn due to the resilient feature, thanks to sev- zine, that we are again publishing -inch diameter great stress put on the wing this data. The first part of the eral turns of / which crumpled up or simply round rubber band. broke off at this critical junc- article appeared in the August If the prospective builder of ture. issue and is concluded here. Many this sport plane is a swimmer, Therefore it is important to have been success- it will probably be a very good remember before attempting to of these planes idea to first try out the plane fly any airplane, whether fac- fully built and flown. The plane is as a seaplane, fitting pontoons bottom of the landing tory or- home built, to stand on will fly 35 miles to the economical and gear vee's, instead of the the wings and pull on them so of gas. The cost with as to see that they are good on a gallon wheels. With the pontoons, and strong. The "flying an Anzani motor totals about the weight of the plane will be course" cited above, as well as $1,250. greater and no smaller engine many of the leading books on than the Anzani 30 -35 h.p. flying, tell how to check up all three -cylinder type should be of the angles of the wings ac- tried. A little experimenting curately and also how to put a test on them, so as to know will have to be done in order to find the best position of the just how strong they are. As pointed out in the U. S. Army pontoons under the plane. Flying Manual, it is very important to carefully check up the It is strongly recommended that the builder secure flying various angles of the wings and the angle of one wing with instructions from a flying school or licensed pilot. However, respect to the other, for on these factors depends the stability if this is impossible for financial or other reasons, the fol- of the airplane when in flight. lowing hints will be useful. Taxi slowly around the field, getting the feel of the flipper and rudder control. When Selecting Wood once the pilot can taxi in a straight line, short hops may be Taxi fast into IN selecting wood for airplane construction only straight tried. Keep a foot or so above the ground. which is very tough, should the wind or slowly with the wind. In making the first flight grain wood, such as spruce, fly and, furthermore, it should be free from knots. ascend to an altitude of only about a hundred feet and be tolerated, climb lies a piece of furniture or a model out of wood over a good landing place. The best angle of Unlike building upon the power with glue and a few bolts, it is not sufficient in building an between 3 and 8 degrees, depending you through the air safely, that the finished plant. airplane to carry sharply. The job simply looks strong; it must be strong, and as afore- The stick should never be pulled back too it is the best idea to get the opinion of an ex- first turn should be shallow and should cover two or three mentioned, be found in the perienced flyer before you venture aloft in any airplane, miles. Additional instructions on flying will whether home or factory built. July issue of this magazine, on page 279.

www.americanradiohistory.com September, 1929 Science and Invention 429 Details of Home-Built Plane

-AILERON HORN AND RIB ASSEMBLY' ALL OTHER AILERON RIB WEBS ARE CUT OUT AS SHOWN BY DOTTED LINES.

TRAILING EDGE CLIPS SOLDERED 3/16 DIA. TO -8- 3 HOLES TRAILING EDGE-, AILERON HINGE '- MAKE 8 o NO.16 GAUGE

BOTTOM WING creL-ti6r DIA.- STEEL TUBE REAR SPAR

AILERON HINGE EDGES LOWER FRONT WELDED AILERON 4 ASSEMBLED SPAR TOGETHER FITTING N\ PULLEY MAKE TWO '66 HOLE TURNBUCKLE CLIP N. 16 GAUGE ST. HINGE WASHER 3' MAKE 8 - N2.I6 GA.

SPAR 4,100

AILERON --END SIDE PULLEY WING VIEW- VIEW SECTION CLIP SIDE 1111111111 Ti VIEW SPAR

AILERON HORN MAKE 2 OF N2. 20 GAUGE STEEL

3/16' DIA. BOLT END UPPER FRONT VIEW SPAR FITTING FLYING WIRE MAKE TWO SHACKLE N2. 16 GAUGE STEEL

r X Ng. 18 -GA. TUBE -SIDE. VIEW-- i 25" a1111/et FRONT STRUT 7/e:TDuIsAE. X Algol* DIA. X N2.I6 N2.I8 GAUGE , 1---1-1-"D GAUGE STEEL TUBE 8 .;,,,,cr 27 '

REAR - TOP STRUT, 'A

, VIEW- , , Ng. II -- , s \*0411111 , GAUGE , , STEEL TUBE ,,,,,,,,,,LANDING AXLE METHOD OF BRACING COLLAR BOTTOM WING SUPPORT AXLE "i MAKE TWO - FRONT VIEW

The details of the aileron horn and rib assembly are given in the The tubular construction shown, at the lower right-hand corner is drawings at the top of the page. The illustration at the center for the landing gear vees, the axle being resiliently mounted at left shows how the aileron horn is made from a piece of sheet the lower ends of the vees by means of standard airplane rubber. steel, bent to the required shape. The details of the lower and The method of bracing the bottom wing support is also illustrated upper front spar fittings appear at right center. in the above drawing. (Additional drawings on next page)

www.americanradiohistory.com 430 Science and Invention September, 1929 Sport Plane Control Features

ELEVATOR DIAGRAM OF CONTROLS RUDDER ON SPORT PLANE ELEVATOR CONTROL ELEVATOR CABLE . AILERON. RUDDER CONTROL \ \ CABLE -STICK

! -- - ' - ELEVATOR CONTROL -- - CABLE ELEVATORCRANK ! PULLEYS AILERON LINEN OR COTTON WING COVERING TO PULLEYS .i CROSS N EXT STITCH' !RUDDER BAR ---- SECTION OF RIB SHOWING -- STRING AILERON CONTROL CABLE HOW COVERING PULLEYS -- IS FASTENED WING WINGS ARE COVERED WITH A FRAME COVERING LINEN OR CLOTH. TO GOOD GRADE OF ALSO DOPED THE CLOTH IS SEWED IN THE FORM STRIP WITH TO E NTERING AND OF A SACK CONFORMING TRAILING EDGES. THE SHAPE OF THE_WING. TAPE DOPED TO RIBS NEEDLE KNOT

WING SECTION LONG NEEDLE IS PUSHED THROUGH WING FROM THE TOP, THEN BACK THROUGH ON OTHER SIDE OF RIB, TIE A KNOT AND PROCEED TO THE NEXT STITCH. METHOD OF COVERING WINGS, WHEN WINGS ARE \AFTER APPLYING ONE OR AILERONS, FUSELAGE, RUDDER COVERED WITH CLOTH AND TWO COATS OF DOPE, A AND ELEVATORS. SEWED APPLY ONE OR TWO CLOTH TAPE ABOUT 11/i WIDE COATS OF DOPE AND COATS OF DOPE. DOPED ONTO EACH RIB TO FINISH WITH FOUR IS THREE COATS OF A GOOD GRADE STITCHING. TWO OR COVER OF SPAR VARNISH. I STRUT FITTING BOTTOM WING_

I STRUT FITTING UPPER WING END VIEW SIDE VIEW END VIEW SIDE VIEW UPPER REAR SPAR FITTING LOWER REAR SPAR FITTING MAKE TWO - GAUGE STEEL MAKE TWO N°. 16 GAUGE STEEL

The control system for the sport plane is shown in the above The airplane cloth is sewn to the ribs of the rudders and aile- drawing. The cables leading from the control stick to the ailerons, in the same manner as that shown for the wings. These are composed of standard steel cable 3/16" control members have their cloth treated with dope, which is rons and tail rudders and in diameter. The horizontal and vertical rudders as well as the followed by two or three coats of spar varnish. The upper ailerons are strengthened with a number of ribs. lower rear spar fittings are shown in the lower drawings.

www.americanradiohistory.com September, 1929 Science and Invention 431

Hints on Flying a Glider By Henry Townsend Gliding Is Undoubtedly the Great- est and Most Rapidly Growing Sport We Have Today

Above we see a glider of the enclosed fuselage type in flight. Note launching rope on ground.

THE greatest sport in America today is undoubtedly that of gliding. Not all of us have the financial means to afford one of the better built gliders, such as that shown in the photo opposite, but by following the plans given in the past few issues of this journal, a group of young men may readily build a successful glider and receive a vast amount of pleasure and thrills with it, not to mention the real aviation experience they obtain. It has been said by many aviation experts that it is more difficult to skilfully fly a glider than it is a regular engine -driven plane. With the airplanes of today, especially those fitted with the Handley -Page slotted wings, or else having a design of wing giving great stability in flight, the engine will pull the student aviator through the air, and his major difficulties lie in the successful taking off and landing of the Chicago glider enthusiasts ship. Gliding is therefore a desirable ready to launch one of their man -carrying gliders. first step. After being started by pulling on the rubber cords, the glider to a With gliders, one has rose height a very good control of of 50 feet and was then flown by the pilot for a distance of 500 feet. the whole situation, and the student flier does not have to take unnecessary chances at all when he is learning to manipulate the controls of the glider. By the ailerons at either end of the wing, as well as the horizon- having the glider towed behind an automobile, for example, tal rudders at the rear of the glider. a low speed of say ten to fifteen miles an hour may be em- Gliders have been launched by attaching one, or in other ployed, so that the glider just flies cases two, cables, as the diagram along a . short distance above the MORE GL herewith shows, the cables being earth. In this way the student pilot IDER DATA either pulled by men running down learns how to keep the glider on an COMING a hill or else attaching the cables to even keel, by working the control automobiles. One of the cleveres t stick and changing the position of Watch for it! tricks lies in the utilization of rub ber shock cord, such as that used on the under -carriage of planes, suitable lengths of this rubber cord being secured to ordinary ropes, as the diagram shows. A tail rope is either held by a group of men or preferably secured to a release trigger mounted on a stiff peg driven into the ground. The two groups of men walk forward at a diverging angle, as indicated in the picture, and when the rubber cord has been stretched to a fairly high degree, the pilot gives the signal -the tail rope trigger is released and the glider is shot into the air at a high velocity. It goes without saying that a green pilot who has never flown a glider should never be catapulted into the air in any such manner as this. He should have learned through previous lessons how to keep the glider on an even keel when being towed behind an automobile. We presume some The diagram above shows arrangement of rubber cords Al and B, joined to manila ropes of our glider friends will shortly be C and D, also self -releasing ring on hook of nose of glider and position. of men at wing building gliders with pontoon hulls, so ends X X and men at tail release rope. that they (Continued on page 451)

www.americanradiohistory.com September, 1929 432 Science and Invention L. Article No. 13 By H. Weatherby in a Series Wood Turning

Quaint old pictures make excellent plaques. They are glued Frames to the wood and varnished. Round picture frames are easily made and solve many of the and framing problems for wood Plaques workers who have lathes.

Turn rabbet in frame Turned Picture Frames

/1/i" IN order to secure a truly professional -like job of picture framing, we usually have to Turn chuck to fit rabbet take our work to one who is 1111111111111111111111111 equipped to handle this sort of a job. The ordinary home mechanic doesn't have facilities for making Press freme to chuck moulding; and if he buys the i moulding, it costs him nearly as

1 111 1 1 11IIIIIi 11 much as the frame made up would cost. He doesn't have a miter clamp, and probably lacks a fine For cutting circles of Turn ° ' opening outside cutting miter saw ; and, viewing all glass, a template is first of the arguments against framing made. After the circle a picture, he usually decides that has been scribed on the the easiest and cheapest way out of glass with the cutter, the glass is tapped gently on it is to have it done for him. the bottom side. Drawing do not hold, Steps in turnreg. These arguments at bottom of page shows however, for a round frame. The types of molding. most beautiful and delicate of mouldings may be turned and deco- about /" smaller than ration may take any form desired. size is to cut a template, It is true that all pictures cannot be either of thick card- framed in round frame, but on the board, using knife or other hand there are a great many scissors, or out of a pictures that would look better in a piece of thin wood on round setting than in the square or the lathe. This must be rectangular one which they perhaps the glass size desired. already occupy. This is particu- Lay this template on the glass and with larly true of portraits and espe- an ordinary glass cutter, purchased cially of old ones that have been in from the "five- and -ten," cut carefully the family for years or generations. around the template, being careful to Nothing sets them off like a simple get a good cut the first time around and ri round, black frame. avoiding a going over. The construction itself is simple. Now, tapping gently from the under The thing that will probably worry side, work around the circle until the the prospective builder first, if he circular section, if it is carefully han- is already familiar with his lathe, dled, will drop out. In case difficulty is is the cutting of the glass. Of experienced in getting results this way, course a professional glass cutter sections on the outside may be removed could do this with little trouble, but by cutting into the circle and breaking why take it to a professional when loose a piece at a time until all outside Upper-frame in first one can do it himself ? glass is removed. These steps are fully stage. Lower -finished The first step in cutting a piece illustrated and with some slight possible frame. of glass to the desired shape and breakage, a (Continued on page 4i 1)

www.americanradiohistory.com September, 1929 Science and Invention 433 How to Make It

Bending Sheet Metal

WITH the aid of two pieces of wooden block. For final forming, the angle iron, one about 3 inches rough bend is placed in the groove long and the other a foot or more in of a large piece of angle iron and the length, sheet metal can be bent ex- smaller piece placed pertly in a professional manner. on top, as shown After in the photograph. A cold chisel rest- the bend has been indicated by a line, ing on the small piece is struck a sharp the metal is bent slightly with a pair blow, forcing the of pliers or with light metal into conforma- blows of a tion with the shape of the angle. cold chisel. Next, the metal is This further will result in a sharp bend having a turned by means of a hammer and a clean edge. -Walter E. Barton. Constructing a Heliograph By L. B. Robbins

-- UNSILVERED SPOT because the signals can be made absolutely secret. They cannot be even seen or read out of line of the two instruments in action.

The base should be cut from % -in. REAR VIEW hard wood, wedge- shaped as indicated c TOP VIEW MINUS MIRROR by "A." The back is 4 in. wide and tapered to 1A in. wide at the front and is 12 in. long. Scribe a line down its SPRING FOR KEY exact center. Then drill a ;A -in. hole 4 in. from the back, on this line, for the pivot hole. Also drill a second -in. v / SIDE VIEW hole close to the front end and a small hole right DETAIL OF KEY at angles to it through the edge for a set screw. Then cut out a } sub -base, B, 6 inches VANE , square. A A-in. t - -_-- POKER hole should be drilled through its center CHIP 4.= and countersunk below. Pivot the two together with a wide, flat washer he- LIGHT SPRING,,. + - tween and countersink the bolt head in the recess in the A' top view of the instrument without the sub -base B. Tension mirror and details of the key are shown in between the two should be fairly stiff, the above illustration. but must allow them to turn smoothly. TRIPOD SOCKET- Just in front of the bolt in B drill a 12" NOTWITHSTANDING the advent second hole and force in a tripod socket of radio for long- distance signal- taken from a discarded camera. Use ing the heliograph still is extensively cement or glue to hold it firmly. ! side and rear view of the heliograph used by appear above. The instrument operates the armies of many nations for Screw two metal uprights, C, to the with a key signaling in exactly as a telegraph is oper- bright weather. This is sides of A (Continued on page 460) ated and is readily portable.

www.americanradiohistory.com 1929 434 Science and Invention September, Shop Mechanics Waste Ball Kink FIRST PRIZE, $10.00 Flooring Remover 21 handy flooring tongs The usual ball Blow -Pipe Guide can be made by taking of waste k e p t two pieces of five - HANDLES on a bench or eighths -inch steel r o d , in a tool box about 3 feet long, and can be handled bending them to shape more easily by shown. Drill for a or as 3- cutting four three -eighths -inch rivet five bands from and sharpen the points %ií /PV-tit"V- " an old inner well. To use, place the tube about one - to n g s over the floor STEEL eighth inch in and press the f RÚBBER BANDS width and snap- board RODS BALL CUT FROM OLD handles together.-Cleo INNER TUBE ping them OF WASTE, around the W. Morris. loosely packed ball. As the ball gets smaller, the bands compress it, holding the waste together. Frank W. Bentley, Jr. RIVET Grindstone Repair

PATCH

SHARPENED The above illustration shows a blow pipe TO POINT equipped with an ,adjustable gauge or guide. With the aid of this adjustable How to Read a gauge, a more narrow and much neater Micrometer cut will result. The distance between the tip and the iron can be adjusted according In the most to the thickness. Both edges of the cut will usual form the be sharp and the lower one is almost free micrometer com- from oxide. Fred Kautz. prises a frame, Chipped grindstones may be repaired by A, carrying the drilling two holes at the point of breakage anvil or fixed and patching with a mixture of one part of measuring point, cement and two parts stone dust. -August B, and a spin- Jeff ers. dle, C, attached Soldering Cylinder Scores to the thimble, E, which latter Flushing Surfaces moves over the 111111 sleeve, D, fixed to the frame. Both sleeve and spindle WOOD BLOCK One of the best carry graduations as shown. The part of ways to flush one within the sleeve and the thim- surface up against the spindle CUT TO FIT ble has a thread of 40 to the inch, which HEAD another is by fits a nut in the frame. Hence, one complete using the device turn of the screw moves the spindle one- illustrated. This fortieth of an inch or 0.025 inch. The consists of a MACHINE BOLT number of turns given the screw is shown spool, a machine on the sleeve D, each sleeve division, bolt and a block marked 1, 2, 3, 4, etc., representing tenths of wood cut out an inch. The beveled edge of the thim- to of receive the ble has 25 divisions, and rotating one of head of the bolt. moves the spindle in spool these marks to the next, Place bolt one -twenty -fifth of one -fortieth of an inch block of wood and or 0.001 inch. To take a reading, multiply on bolt. Delmar the number of marks shown on the sleeve Overstake. by 25, and add the number of divisions on the thimble. Harry S. Wake.

Removing Rusty Screws PRIZE AWARD RUSTY SCREWS Anyone who is handy with tools may re- Each month $10.00 will be given pair a score in the cylinder block with to the contributor of the best shop solder. Very strong acid must be used wrinkle. Shop Mechanics is a new when soldering the score, which should be department, and garage men, shop .,. well cleaned and scraped; otherwise the solder will not stick to the cast iron. The workers and those engaged in RED -HOT SOLDERING IRON solder can be applied while the motor is in similar occupations will find much the car, or the block may be removed and of interest on this page and are the To remove a rusty screw, apply a red -hot set up as shown in the illustration. After asked to submit their own favorite iron to the head for a short time. The heat solder has been applied, the surplus is re- will readily loosen the screw and it may be moved with a half -round file. The solder kinks to the editors. removed with a screw-driver while it is will remain in the score until the cylinder still hot.--A. C. Wilson. wall wears away. A. C. Wilson.

www.americanradiohistory.com September, 1929 Science and Invention 435 Wrinkles Bottle Trick Recipes Exhaust Pipe Hose and ._.

k ®«AIKI, riiummr;alimmmaumu Formulas PIPE !IIJIIIIIIIIIIIIIIIMMI1IIIIIImf !`(. -:.t w i %/il Remedy for Poison Ivy V-447-111/? _ Swab the poisoned area with a five - TO EXHAUST per -cent. solution potassium PIPE of perman- While working ganate. This solution leaves a in the garage with the brown motor of the car running, the deadly car- stain, but can be removed by repeated bon monoxide gas can be led to the outer washings with soap and water. -Con- air with a piece of two -inch pipe with hose . Fill a large bottle with water to one -eighth tributed by Clifton Ask. attached. The hose is slipped over the ex- inch of the top. Grasp neck firmly with haust pipe and the other end of the pipe is left hand and, using a glove or cloth as led outside the garage. -Ray H. Balken. protection, strike the mouth of the bottle Door Pulls with a short, swift stroke of the right hand. Pry the cross chains off an old tire The sudden compression of air in the neck chain and fasten the ends to the door, Stencil Roller of the bottle is sufficient to shatter the glass. leaving a little slack. Wrap the chain -E. R. Vass. with tire tape, so it will be easier to grasp. -Contributed by Clifton Ask. PLUSH WOOD Electric Pot ''COVER ROLLER

TIN CAN HANDLE THREAD Model Airplanes d Model airplanes are generally made of wood. A very good substitute for wood in some parts of the plane, such STENCIL as the body and wings, is viscoloid or celluloid, which can be obtained in THE ENDS many colors and any thickness. It is OF WIRE TWISTED AND PUSHED easy to cement and 'can be sawed and INSIDE drilled the same as wood, also it can be For neat work a plush roller not only HANDLE CIGAR LIGHTER heated and bent any shape. Transpar- makes a cleaner stencil, but is much quicker in operation. PLUG ent viscoloid can be used for wind- fl roller for spreading sten- shields, etc., or to go over and protect cil colors is shown above. -Frank H. . Carlberg. An electric cigar lighter, purchased in the letters or figures.- Contributed by Les -` five-and- ten -cent store, a small can and an lie Carpenter. old handle can be assembled to form an electric melting pot, as shown above.-W. Lentil Separator H. Happe, Jr. Keeping Workshop Hardware A good method for keeping screws, Small Vise nails, washers and various workshop supplies is to use glass jars with screw tops, several sizes of which may be purchased in the 5- and -l0 -cent store. May- onnaise jars also may be used. When buying screws, etc., by the box, tear off the top label and place it in the jar for identification. As the jars are of glass, you can always see what you have got on hand. Edmund Mills. Auto Trouble or Spotlight Con- nection Secure an ordinary porcelain base electric light socket and a screw plug from the 5- and -l0 -cent store. Locate the socket in a convenient place on the body of the car just below the instrument board and on the driver's side. Run one wire to the ignition switch or other convenient place, connecting with the positive side of the battery, and the other to the metal body of the car (for one -wire system). A metal can, provided with a hole with the upper section indented, can be used for sep- By cutting off tips of lettering pen and Attach pronged part of the plug to arating lentils. The lentils are thrown into soldering to brass plate as shown, a vise the wires on the lamp and you will have the box and follow the water current run- f or delicate work may be had and can be a handy connection for your lamp. - ning out, while the small stones remain in screwed to work bench. E. R. Vass. Edmund Mills. the bottom.- Charles Mohr.

www.americanradiohistory.com 43 Science and Invention September, 1929 Readers' Opinions and Comments Will Be Welcomed by the Editors What Our Ionaeo and Oxygenator in my practice for quite a while, and it is really remarkable how fast it works in relieving neuritis pains. In fact, in almost any Editor, SCIENCE AND INVENTION: condition, it seems to have a powerful action for good. Espe- I have been a reader of your magazines for many months, cially with my old patients, or folks past 70 years of age, it seems being a true scientist at heart, and ready at all times to investi- to have a remarkable rejuvenating effect. Now I realize that gate and fairly try out all things given to science by the great it is only a bundle of wire, but "boy, oh boy," how fast that minds of the day for the cure of disease. I wish to set you bundle of wire will cure a case of sciatica or neuritis or cure a right in regard to two of the most wonderful things ever given case of varicose veins. In view of the fact that I am a successful drugless physician, with a large practice, I think I can, after a large experience, speak with authority on these two instruments. urlxmitori ifee Pros Why is it that wonderful inventions and even the wonderful science of chiropractic, which is recognized now in many states of our Union, is condemned and criticised? SATURDAY, NOVEJIBER 5, 1930 After all, gentlemen, clinical results are what tell the tale. Also, I wish to add here that the Ionaeo I have been using was given to me by one of my patients who cured herself of a long- standing complaint. Proof of the pie OXYGENATOR SALE is in the eating. I am simply writing this to you because I like to see credit given where credit is due. D PROHIBITED NERE Concerning Mr. Wilshire's death from two diseases which the Ionaco is supposed to cure, I would answer you thus : There comes a time in every man's life when the disorganizing Vermont State Board of Health powers of nature are greater than the physical body cells can Investigates Claim. of Mana. stand, and we have the dissolution of the physical and mental, factums of Instrument. which is death. No doubt in A reproduction Mr. Wilshire's life had come that of the first part particular time, the same as nature has decreed that- it shall come to everyone of a long article M through some means, even to you and me. appearing in the DEVICE PRONOUNCED A FAKE The polarizer of the Oxygenator is filled with coke dust, so Vermont news- you claim. called the Well, I don't care it is filled paper Tests Show a Tube Filled with what with. I'll tell you what Burlington Free can be done with it in a case of pneumonia. When all other a Black Powder Which Is e. Press. This is methods fail to make a patient perspire and the temperature is Crude Mixture of Inert descriptive of high, I can, by placing the polarizer in the ice water and proper the results Substances connections made on which the Ver- wrist and ankle with contact plates, room mont State properly aired, cause the patient to perspire freely in a short Board of Health time. Many lives thus have been saved by the reduction brought got after inves- STATE OF VERMONT STATE about in the temperature, through more rapid oxidation of the tigating the effi- BOARD OF HEALTH toxins. cacy of the de- LABORATORY OF HYGIENE So, if it is the coke dust in the polarizer which accomplishes vice known as the desired result, many congratulations to the man who had the Oxygenator WAANJICL NOTICE brains enough to discover that coke dust would do this, and I (Oxypathor). know it will do it, and I don't mean maybe. Vlolatioe .f Vermont Pare Reed Lew Now, dear friend, I am not writing this letter in a spirit of ob Laeeratery N.. sofa antagonism. I am simply writing this letter that it may be Mr 14 J. Preston. Mgr. Vermont published, and some poor sick individual may be helped in seek- Oxygenator Ca- Burlington, Vt. You are hereby Informed that the ing health. following material ^O O. Duplex Thanking you again for further consideration of this matter, Oxygenator obtained of you Oct 106. 110. does not campy with the I am Vermont Pure Fold Laws. Re- D.C., Ph.C., marks: misbranded: claim. on label L. P. Roys, are misleading and extravagant Little Falls, New York. Your attention la called to Regu- lations X111E and section. 6,167 -6.- (In the October, 1927, issue of Science and Invention maga- 171. Chapter 734 Public statutes. A entitled, violation of the above Yonder* you zine an article appeared on the subject of the lonaco, liable to pre.eeutloe. consists of a coil large Very truly pouce. "The Ionaco Swindle." The apparatus B. D. 6HOLSON. 1L A liscr.try Brattleberq flat. 31. 1610. g all :ed swindle. according to n

to sick and suffering humanity outside the science, art and philosophy of chiropractic, namely, that wonderful something called Ionaco and Oxygenator. I believe that after eight years of use of the Oxygenator and two years' use of the Ionaco, I can speak with good authority in defense of these wonderful modalities. My mother was cured of a stoppage of the nasal passages by the Oxygenator after all other methods had utterly failed. Specialists were all stumped on the case. After seven days' The Oxypathor itself. For this piece of metal pipe, filled use, eight hours per day, of the Oxygenator, the condition in her with an inert product, the sum of $35.00 was paid. This was sinuses broke loose, and her head condition cleared at once, called the Oxypathor, but was originally sold under the name enabling her to breathe through her nostrils, the first time in of Oxygenator. weeks, except when the silver tubes were inserted. This is only one case; I could cite you hundreds of them. enough to encircle the body, even though it is generally worn Now as to the Ionaco. There is no question but that it is hanging over one shoulder. This coil contains 626 turns, or a specific for all types of rheumatism. I have been using one 3,411 feet of ordinary No. 22 single cotton covered enameled

www.americanradiohistory.com September, 1929 Science and Invention 437

Questions and Discussions of Readers Think General Scientific Interest

copper wire. In the original advertising, Mr. Wilshire claimed attached to the wrists. Yet at the trial hundreds that of witnesses there was a mile of wire in it. He evidently never meas- came forth with testimonials. Subsequently other organizations, tired the length of the wire himself. There is also a separate such as the Oxygenator and the Oxybon, were declared fraudu- coil, a miniature of the large one, to the two ends of which a lent and were excluded from the mails. It follows then that you have been using a product officially declared fraudulent by the U. S. Government, and you commend it from the standpoint of clinical results, which results cannot, by the greatest stretch of the imagination, be ascribed to the piece of gas pipe.- Editor.) Athlete's Foot Editor, SCIENCE AND INVENTION: I have recently heard of an ailment known as Athlete's Foot. Can you give me some further information about this? J. E. D., New York City. Athlete's Foot is the name commonly given to ring -worm of the foot, and Dr. Chas. F. Pabst, chief dermatologist of the Greenpoint Hospital in Brooklyn, says that, as a rule, it begins between the toes where it is often overlooked, and spreads gradually along the sole and the sides of the foot. The skin becomes pink or red in color, and the affected part is frequently covered with a white scale or crust. The scales may be dry or moist, and when peeled, leave an inflamed area. The condition extends very slowly, and is accompanied with slight itching. The ailment This line illustration is reproduced from the October, is caused by a parasite which is a vegetable fungus. The fungus 1927, issue of SCIENCE AND INVENTION Magazine, is very common and is found on the floors of gymnasiums, where the photographic illustration was used for ara swimming pools and bathing establishments. The fungus takes article entitled "The Ionaco Swindle." easy hold and grows rapidly when the feet are warm and moist. The disease can be cured by applying a mild antiseptic, and it must be completely eradicated, otherwise it may start anew. Hence the treatment in some cases is quite long. Dr. small incandescent lamp is attached. If the large coil is con- Pabst claims that the condition is very prevalent nected to a source of alternating current and the small coil held in America.- Editor. near it, the lamp will glow. This test is supposed to indicate Shortening Hours of Sleep the efficacy of the coil of wire. Attempts at scientific explanation are made in the advertising literature of the Ionaco. The Editor, SCIENCE AND INVENTION : If science understands just what chemical phenomena apparatus itself can be built at a cost of approximately $5.75. takes place within us when we sleep, why can't It sold for $58.50 originally, although (judging by the literature some means be devised that will enable us to get a full night's rest equal to hours which we received) some organizations have cut down the eight sleep in a much shorter period? As it is, a man spends twenty - price to only $40. Testimonials for this product have come five solid years of his life sleeping if he lives from all over the country, just as they have for every fraudulent to an age of seventy -five. A lot of people would welcome the opportunity medical treating device. As a cure -all it is as worthless as a of being able condense rabbit's foot. to their sleep. Perhaps a glass- enclosed bed with added oxygen and sun As for the Oxygenator, this product was originally sold under rays (arc lights) playing over the naked body would help us to this name for some time, and then its name was changed to cut the time down. Has anything ever (Continued on, page 459) Oxypathor. It is merely another of the gas -pipe cures which have been foisted on the public, and is comparable to the Oxy- genor, the Electropoise, the Oxydonor, the Oxybon, and the numerous other products of similar ilk. The article was examined in the laboratories of the University of Vermont to THINGS do not always run determine the composition of the material with which the cylin- smoothly for the man who der was filled. The laboratory stated that "The hollow interior . . . is filled with a black powder, which analysis discloses chooses magic as a professional to be a crude mixture of inert substances, apparently the waste - cu- or by- product of a manufacturing plant. The powder is a rough calling. Hair breadth escapes, mixture of iron filings, clayey material, and a dark colored rious accidents, ludicrous moments carbonaceous mass, apparently nothing more than coke dust, or carbon black. As a result o fthese findings, the State Board and interesting anecdotes are of Health of Vermont declared the Oxygenator or Oxypathor, ladled from the caldron and placed as it was subsequently known, to be physically and therapeuti- cally inert, and on Saturday, November 5, 1910, the Burlington before the readers of this publica- Daily Free Press announced that the Oxygenator sale was pro- tion in a new series of articles to hibited in the state of Vermont. An official proclamation was issued by the Australian Government, prohibiting the importa- commence with the next issue. tion of the Oxypathor (Oxygenator) into that country. On November 14, 1914, E. L. Moses, of Buffalo, N. Y., the General Intimate glimpses of the lives of Manager of the Oxypathor concern, was found guilty of using conjurers and escape the mails to defraud and was sentenced to serve 18 months in artists never the Federal Penitentiary. He appealed, but the Appellate Court before published will be featured confirmed the judgment and he had to serve sentence. At the in trial it was brought out that the Oxypathor (Oxygenator) costs the new series called, "When $1.23. It sold for $35. Purchasers of the Oxypathor could Fate Tricks Tricksters," by have obtained just as valuable curative effects from an empty tomato tin, filled with coke dust, closed, a string attached to it, Dunninger. and the product dropped into water after the strings were

www.americanradiohistory.com 438 Science %and Invention September, 1929

The photograph at the left shows the Canadian National Railways train which was used during the telephone demonstration just before it left on its run. Below is Mr. W. D. Robb, the Vice - President in charge of Telegraphs and Telephones of the Canadian National Railroad, phoning the first message from the moving train. Note the antenna stretched across the top of one of the cars.

You Can Now Call Your Home From Moving Train ON May 5th of this year the engineers of the Cana- dian National Railways publicly demonstrated a system of radio telephony whereby passengers on a moving train were enabled to communicate with stationary points served by ordinary telephone service. There are many advantages present in such a system. Those on board the train need not lose touch with the outside world, so to speak. In making a transcontinen- tal trip it often happens that a day or more passes before the traveler can reach a telephone center of a size sufficient to warrant placing a call and completing it before the train pulls out. Not until the next stopping place is reached can the traveler communicate with points past or ahead. Shortening the time of communication and making such contact available at all times will mean much to business men. Germany is perhaps the only country where a train radio communication system is used, but the Canadian arrangement is superior in some ways. A special test car, equipped with a laboratory, was Mr. W. G. Barber, General Mana- used by the Canadian National (Continued on page 463) ger Canadian National Telegraphs, receiving the first message. TRANSMITTING RECEIVING

ANTENNA ANTENNA TELEPHONE , TELEGRAPH LINES, ETC

Mr. H. Lang, assistant engineer, is shown at the panel of the terminal station control board, at Davenport Station, Canadian National Railways, Toronto. The drawing at the left illustrates how the telephone system is made possible. The telephone and telegraph lines paralleling the railroad tracks pick up the signals from the train by induction and also transfer signals to the moving train in the same manner. Filters are placed in series with these lines, so that there is no interference with the existing telegraph and telephone messages which are carried by these wires.

www.americanradiohistory.com September, 1929 Science and Invention 439 The Radio Robot An Electrical and Mechanical Set Tester By J. E. SMITH, President, National Radio Institute AMECHANI- CAL and electrical trouble- shooter -a radio Robot, as it were, for the service man-has been designed and built by Ralph Stair of the Bureau of Standards. The functions of a tube tester and rejuvenator, the trouble -shooting f o r condensers, t r ans- formers, and other Above is a photograph radio parts, and the of Ralph Stair with his testing of complete portable set tester, radio receivers have which is entirely self - been combined into a contained. single unit-withal, a test kit without a counterpart in the completeness of its diagnosis of sick and crippled receiving sets. The average human trouble -shooter, detailed on service errands by retail radio stores, is properly equipped to test a vacuum tube for filament The above photograph shows the radio Robot in use. The tester can be used emission, and with a pair of head telephones he with all types of receiving tubes as well as with parts and complete sets and may be enabled to determine a broken circuit in is provided with both d.c. and a.c. meters. a transformer. However, his facilities are often inadequate to locate many common troubles with which is unmistakable proof of a short -circuit between the plate receivers are afflicted. For instance, a rectifier tube may and filament elements of the vacuum tube under examina- light and yet not function properly and a short circuit in the tion; if, on the other hand, the other tiny lamp lights, there receiver may necessitate a disjointing of the parts. If the is indication of a short-circuit between the filament and grid service man is pretentiously equipped with test kits, the elements of the tube under test. If the two lamps light latter are so numerous as to defy ready transportation, and simultaneously, there is indication of a short- circuit between their sum total of testing deficiencies are too glaring to' enu- the grid and plate elements. merate. This conspicuous absence of a unified and complete radio Tube Testing tube, and set test kit, one that would test all types of receiving tubes, as well as parts" and complete sets, prompted Ralph HE tube-testing section so thoroughly comprehends the Stair to design the compact and thorough- working outfit we diversified needs of a trouble- shooter that practically are about to describe. The finished product gives added every type of radio receiving and rectifying tube can be virtue to the threadbare adage that fiecessity is the mother accommodated, including past and present models. The test of invention. For Mr. Stair was impressed with the needs board contains three sockets which, with the aid of a set of for such a trouble- shooter in diagnosing sick and crippled adapters, accommodate all tubes of the old and new 199 -type sets of his neighbors and at home. base, the WD -11, old and new 1A-type base and UY -227 or its equivalent (the new alternating current detector tube). Mechanical- Electrical Tester Since the WD -12, the alternating current amplifier tubes and most rectifier tubes have the new UX -type base, all common HE mechanical and electrical trouble- shooter or radio tubes of American manufacture are readily accommodated. 1 Robot weighs approximately 25 pounds and is relatively This is not the case with the ordinary tester. small. It is completely self- contained, with the exception of The tube -testing compartment of this radio Robot, by use two insulated wires having metal feet for associating the of resistance units in parallel, will indicate the filament test kit with a transformer or other source of suspected emissions of vacuum tubes having a plate current as high as trouble. The panel on which the testing devices rest is 2/ amperes. By the same token of completeness which rectangular in shape. Underneath this trouble- shooting characterizes the entire outfit, if the prongs of the three ele- equipment proper is a compartment .for holding soldering ments in a tube are touching this undesirable condition is irons, screw- drivers and other instruments necessary to the disclosed. With a plate voltage range from zero to 200 vocation of a radio service man. This convenient compart- volts, this critical test can be applied to rectifier tubes as well ment for tools reduces the practice of scattering them all as to conventional receiving tubes. Types of tubes subject to over the service man's car to a suitable location, where they the rejuvenation process are accommodated, which includes are readily available when needed. This tool compartment type 201A -a flash of 15 volts on filament for 60 seconds is sufficiently roomy to install all the necessary radio tools and aging at 7% volts for ten minutes. Also types UX -120 and possibly space for a "C" battery or an "A" dry -cell and UV -199 are likewise accommodated, a flash of 10 volts battery. for 30 seconds and an aging process of for 10 minutes. The 7 -by -8 -inch panel for testing as well as rejuvenating The turn of one switch gives filament voltages variable by radio receiving tubes contains two small automobile lamps. predetermined steps. These tiny lights occupy a position, in miniature, on this The human trouble- shooter, upon the introduction of this trouble -shooting board corresponding to coastal lighthouses radio Robot, would not be required to carry his inseparable as they flash their beacons to troubled navigators. For in- head telephone set for testing purposes. By opening the stance, if one of these miniature lamps radiates a glow, his circuit in this new test kit and (Continued on page 475)

www.americanradiohistory.com September, 192 440 Science and Invention New Radio Devices

Shield Grid Clip vided. The needle merely fits loosely into a steel NEW England manufacturer is tube and is held there by A now making a shield clip or magnetism. The only grip for use with UX -222 and UY -224 attention which the tubes. The clip is made from spring needle holder requires is Figs. 1 and 2 metal in one piece. A slight pressure an occasional applica- above show the of the thumb and forefinger allows the tion of a small quantity internal connec- clip to be opened so that it may be of vaseline to the inside tions of the im- the control grid terminal holder pedance adjust- slipped over of the needle ing transformer. screen grid tube. The control tubing. This prevents of the Fig. 1 shows the grid is brought out at the top of the corrosion and allows the input connec- bulb to a special contact cap, which has needles to be removed tions, and Fig. a maximum diameter of .369 inch. The easily. No special coup-. 2, the output con- opening of the clip has a slightly smaller ling transformer is re- nections. The diameter than the control grid terminal quired as the pick -up is instrument ap- so that good contact is assured. By wound with a high im- pears in the referring to the illustration it will be pedance winding which photograph at seen that one end of the clip is provided works satisfactorily the right. with a lug for connecting the control through an ordinary in- grid lead. The lug is stamped out of put transformer or di- the single metal piece. The cap is rectly into the grid circuit of a vacuum frequency. With different types of easily removable and is provided with tube. units the impedance - frequency charac- a handy finger grip. Radio set con- The lower pick -up has excellent re- teristics are different. Transformers are structors will save niuch trouble and sponse characteristics as shown in labo- inserted to approximate the proper re- will be enabled to make a good connec- ratory tests. It is equipped with a lation between the impedance of the tion to the control grid by using the mounting plate for attaching directly load and the impedance of the source. grip described here. When repairing It is usually only possible to the receiver or replacing tubes, the con- obtain the correct relation of trol grid connection can be removed in impedances at one frequency a second's time. because the impedance -frequency characteristics of both Phonograph Pick -Ups the source and the load do not rfl HE two pick -ups shown vary at the same rate. herewith are of latest An impedance adjusting design. The upper one is of transformer, the product of a large size and is a theatre New England manufacturer, is pick -up which has been de- designed to adapt various loads signed for home use as to the output of a power am- well as in auditoriums. A plifier. Loud speakers of sev- suspension bridge counter- eral types or different combi- balance makes it possible to nations of reproducers may be use the pick-up on the same connected to the power ampli- record over and over again fier and best results obtained. without destroying the re- The impedance adjusting Two of the latest phonograph transformer of two thereon. . A volume consists cording pick -ups are shown in the above control and adapter are fur- identical primary windings and photographs. The upper has four identical secondary wind- nished for four or five prong been designed for use primarily 1 and tubes in the event that the re- in theatres and auditoriums. ings, as shown in Figs. ceiver is not equipped with a 2. Fig. 1 shows the input phonograph jack. The head terminal block and the connect - of the pick -up is simply tipped back to the phonograph, with leads brought tions for series or parallel operation of and stays in that position while records out through the center of the support the coils. The input leads are always are being changed. This is made pos- standard. The pick -up head is held by connected to terminals 1 and 4. Fig. 2 sible by a perfect balance. a double bar. As in the case of the shows the connection of the secondaries. The needle holder on this pick -up is other pick -up, this one also rests upon The output leads should be fastened to entirely different from those of the the record with but a few ounces pres- terminals 1 and 4. A table is furnished usual types, as no clamping screw is pro- sure. The instrument is finished in a by the manufacturer which shows the pleasing color combination and is among load impedances and connections for the the best which have come to the atten- output terminals when working from tion of this department. an impedance of 2,000 ohms. By proper T h e i11ns- connection of the coils, the desired im- tration at the left Impedance Adjusting Trans- pedance ratio can be approximated. shows t h e former Each primary winding will safely carry shield grid 150 milliamperes of current and each clip at- AMAXIMUM transfer of power secondary winding 300 milliamperes. tached to occurs when the internal imped- When two windings are placed in paral- the control ance of a source is equal to the load into lel, the current -carrying capacity of the grid termi- which this source is working. Most of circuit is doubled. With primary wind -` nal the apparatus used for reproduction ings in series, the transformer works have impedances which vary with the out of a 2,000 -ohm impedance Names of manufacturers furnished upon request

www.americanradiohistory.com September, 1929 Science and Invention 441 Radio Oracle A Monthly Question and Answer Department Conducted with a View Toward Helping Radio Constructors and Experimenters

How a Loop Antenna Operates peres of current may be found to flow in the grid circuit. An oscillating condition in the push-pull amplifier may be (724) B. Selig, Muncie, Ind., writes : corrected by connecting a 50,000 ohm resistor in the "C" minus Q. 1. How is it possible for a loop aerial to function when lead at the point marked X. In some cases, in order to sup- it is only a few thousandths of a wavelength in length? press the oscillations completely, it will be necessary to connect A. 1. If a loop antenna is ro- a choke coil in the "B" plus lead tated so that its horizontal wires at the point marked X. If a resis- are at right angles to the direction tor is used in this position there in which the signal is traveling, will be a loss in plate voltage. then the loop has no length in so far e as these signals are concerned. As Short Wave Transmitter the wave passes, it strikes both IN sides of each turn in the loop at OUT (726) C. O. Burton, Albany, exactly the same instant and the N. Y., writes : voltages generated are, therefore, Q. 1. Will you please give me equal and opposed and there is no a circuit diagram of a 10 meter terminal voltage. This gives the 410 short wave beam transmitter, to- loop antenna its directional charac- gether with the necessary data for teristic. If the loop is turned making the coils? slightly from the zero position. MILLIAMM ETER 1#40'1i A. 1. On this page you will then the voltages no longer cancel find the circuit diagram of a short each other and a voltage will ap- wave beam transmitter having a pear at the terminals. The maxi- e wavelength of 10 meters. As may mum position of the loop is very B+ be seen in fig. 1, the transmitter is broad and the zero position exof the Hartley type. The plate tremely sharp. When a loop an- The test for oscillation in a push -pull amplifier is shown coil consists of a single turn of tenna is used with a radio receiver, above. A milliammeter is placed in series with the C wire about 17 centimeters in diam- it is necessary to tune it to reso- minus lead. eter, and the grid coupling coil is nance with the desired signal. The of similar construction. These maximum inductance of the loop with the maximum capacity coils, together with the capacity between the elements of the of the condenser must give resonance to the longest wavelength vacuum tube, form an oscillatory circuit. The antenna system to be received. The loop should not have an inductance value shown in figs. 2 and 3 is coupled to the transmitter by means of a greater than that required for tuning. The inductance of a coil coil which is of the same size as the plate and grid coils. The an- of wire increases considerably as the tenna consists of two sets of vertical turns are wound closer together. The wires, each set being composed of six maximum inductance is obtained with parallel wires arranged in a circle as a minimum number of turns when shown in fig. 2. The wires are they are wound closely. In order to spaced about three centimeters apart, get the maximum number of turns as shown in fig. 3, and are 1.8 meters for a given inductance which the in length. The parabolic reflector loop requires, the turns should be can be used to obtain directional beam wound as far apart as possible. transmission. Such an antenna can The turns of wire on the loop are be made in the form of a segment of in series with each other, forming a a parabolic cylinder by suspending continuous winding. If the maximum 40 wires from a frame in the forni voltage is to be generated in any one of a parabola. Each of these wires turn of the loop, then the voltage is tuned to 10 meters and they are generated in the two sides of this turn spaced one foot apart. The focal dis- should be in opposite directions so tance should be equal to 2.5 meters, or that they will not oppose each other. 8 feet 2.4 inches. Oscillation. Test for Push -pull Substitute Electrolytes Amplifier (727) H. Scott Roan, Racine, Wis., (725) W. C. Beach, Mt. Hamilton, asks: Calif., writes : Q. 1. There are a number of substi- Q. 1. Will you please give me some tutes for battery electrolytes of sulphuric information, together with a circuit dia- acid on the market. Are these harmful gram, showing how I may test a push -pull to the battery? amplifier for oscillations? A. 1. In reply to this question, we can A. 1. On this page you will find a cir- do no better than to cite several of the cuit diagram of a conventional push -pull important paragraphs from a report issued amplifier. The test consists of placing a by the National Better Business Bureau. meter in the "C" minus lead in order to The principal ingredients found in the determine if any current is flowing in the majority of both liquid and solid prepara- grid circuit. The location of the milli - tions have been Epsom Salts and Glauber's ammeter is shown in the diagram and Salts. Manufacturers of batteries do not under normal conditions there should be approve Figure 1 shows the schematic diagram of the use of such ingredients as no deflection of the needle. However, if of the short -wave transmitter, Figure a substitute for the electrolyte in a lead the circuit is oscillating, several william- 2 and Figure 3 the antenna. (Continued on page 456)

www.americanradiohistory.com 442 Science and Invention September, 1929 Scientific Humor A Monthly Fun Page for Those Who Enjoy a Laugh SOUNDS WINDY NEITHER HARD NOR CARPET Two men were spending the night at CURIOUS LAD -Pa, what does Uncle a hotel where they had their first expe- Sam live on? rience with electric lights. Upon retir- FATHER-Tax. ing, one of them tried to blow out the CURIOUS LAD -Does he ever have a light. The other seeing him, said stomach ache from eating them? ``Don't show yer ignarance; y'u can't -Robert J. Dobbs. blow these lights out." "Well, how do y'u put 'ern out then ?" A STICKY LINING was the reply. MR. BLACK - What's this cream "I don't know, but I heard the feller cheese doing in my den ? downstairs say soniethin' about blowin' MRS. BLACK-Slight mix-up, dear. I out a fuse somewhere." must have spread the sandwiches with R. James. -H. First Prize -$3.00 library paste. -Lida C. Hill. HIGHER MATH NOT RELA- CHERRY -O TIVITY TICK -Say, the amoeba must be some InathematiC+ian. CLANCY -LaSt HARD-BOILED night Í went to (in a crowded TocK -How come? he a party ; while I street - car) TICK -Well, multipljes by di- - viding. Motheral. was talking Why don't you -John someone gave put your feet me a drink. where they be- MIGHT GET PALE POP (in cellar) can't be done. It DINTY -What long? -It was it? HARDER- can't be done. CLANCY- VOICE UPSTAIRS - What can't be BOILED-Listen, done? Gold paint. if I put my feet where they belong, you DINTY-HOW do you feel? POP-Drink Canada Dry ! wouldn't be able to sit down for a -C. Kantarunas. CLANCY- Gilty, very gilty. week! -L. D. Peckenus. -G. Daniel. CAN'T PLACE ME iJ LL jokes published Itere are paid THEN SHE BEANED HIM "Did you ever kilowatt ?" C1 for at a rate of $1.00 each; WIFE -In my opinion, sheep have "Ohm, yes, I often choke coils, too." $3.00 is paid for the best joke sub- very little brain. "Oh, A. C.! mitted each month. HUBBY-Yes, my lamb. -Martha Betty Barton. Jokes must have a scientific strain (Author please send name.) and should be original. - ANATOMICALLY SPEAKING? Write each joke on a separate sheet A base ball park is a regular ball -and- of paper and add your name and ad- CAN'T FACE THIS socket joint! -George A. Field. dress to each. Run upstairs and get my watch. Unavailable material cannot be Wait a while, and it will run down. A BLANK returned. No, it won't; ours is a winding stair - EXPRESSION case. -Fred $rdos. F L A P P E R TEACHER - WIRE YOU SO DUMB? SOME What is the dif- ELECTRICIAN - Where did you get CHEEK ference between that wire? ABSENT- concrete and ab- ASSISTANT -That ain't wire, that's MINDED PRO -

stract ? - yarn made out of steel wool. FESSOR-I want SCHOOL B o -Leslie F. Carpenter. some powder. -Concrete is DRUGGIST - / that which can TOO CIRIUS Some that goes be seen; and abstract is that which can- PRoFEssoR- Shooting stars are the off with a bang? not be seen. - the most disorderly things in the uni- ABSENT- FLAPPER TEACHER -Give examples. verse. MINDED PRO- Smoot, BOY-My face is concrete AMATEUR-Then why do the direc- FESSOR -It's for my sister; I think she and yours is abstract. tors allow them to carry guns. wants the kind that goes on with a puff. -Robert J. Dobbs. -Robert J. Dobbs. -Leslie F. Carpenter. SCIENTY SIMON SCIENTIST

cJow I'LL TH15 IS SCIENCE. L E.550N GONNA 'BE THE 13E AO LE TO No. 34 LACE 13E5T AERIAL GET ALL KINDS 'HE LADDER, SIMON f oN THE OF DX re$DENcy IT , MAH I-F AVE NO .LOCK ITSELF -co SLIP 8Y PD- P5 HE ASceNDS, THE AL C-rfA- THE T' USIH WIC1AN LADDER F_XERTS AGAIr+ST THE TREE ... C'oNSEQueNT- THE HORI20NTAL. L' LOW . THRUST of THE O NO .MD ALOIH, THE C BC CxReç TER -COMES POSH virk 3 THIS. LATERAL INCREASeS ?O THE POINT WHerzg CC IS POLE -ro OVER- COME THE fR(CTION OF THE G2oONO, Me LADDER WILL FALL

www.americanradiohistory.com September, 1929 Science and -Invention 443 Latest Patents Holder for Notice to Readers: Fire Extinguisher Flower Pots and Cut Flowers These illustrated and described devices have recently been issued patent protection but are not as yet, to our knowledge, available on the market. We regret to advise that it is impossible to supply the correct addresses of inventors of the devices to any of our readers. The only records available, and they are at the Patent Office at Washington, D. C., give only the addresses of the inventors at the time of application for a patent. Many months have elapsed since that time, and those records are necessarily inaccurate. There- fore, kindly do not request such information, as it is practically impossible to ob- No. 1,712,986, issued to Joseph Favata, Jr. tain up -to -date addresses. The object of this invention is to provide a water supply for potted plants and to make provision for surrounding the potted plants No. 1,708,869, with cut flowers, the stems of which will be issued to Sound Reproducer Hartmut Buddecke. h i partly submerged within the T s water pro- fire extinguisher is provid- vided for moistening the ground within the pot of the ed with a fuse which trans- potted plant. Provision is made mits fire to a to accumulate rain cartridge by water and deliver it to which the extinguishing sub- the water reservoir of the device so that stance is then thrown automatically upon manual replenishment of water is not re- the burning object. It is so quired except during dry designed as to spells. be adapted for use in connection with a dry pulverized extinguishing substance as well as a liquid one. The casing has an open Eyeglass Cleaner and Polisher ejecting end and the walls are adapted to resist high internal pressure. The cartridge is located at the top of the vessel from which a fuse extends through a tube.

Clinging +l_\If41P `' Figure No. 1,710,989, issued to .Indrew Kelly. This invention relates to toy or decorative figures, which are preferably inflatable. The figure may be bent in any position and No. 1,712,325, issued to David Brandfon. No. 1,712,920, issued to Frederick .4. Kol- is provided with vacuum The device shown above has two pockets ster. The loud speaker shown here com- cups at the fingers and supported on arms pivotally connected. prises a conical- shaped diaphragm, a toes. The vacuum cup The pockets are of chamois or other flex- frame, a flexible membrane for suspending is hollow and made of ible material and receive the. finger of the the diaphragm at a position intermediate rubber, so that by press- hand and the thumb, so that the chamois to the apex and a pair of cord members ing the cup against an may be pressed against opposite surfaces fastened at opposite ends to the frame and object the arms and legs of an eyeglass and permit the desired pres- extending through the diaphragm at right may be held in any de- sure for cleaning. angles thereto. These permit the dia- sired position. Since the phragm to be centered. The conical -shaped figure is flexible, it may diaphragm of this electro- magnetic repro- be made to assume a ducer is free at the peripheral edge and is great variety of posi- Shadow Letter Production supported solely at points intermediate to tions and can be sup- the apex. ported by one or all of the vacuum cups.

Toy Parachute No. 1,713,432, issued to Theodore G. Griggs. The toy shown at the left is composed of a hollow ball of two sections, held together for a predetermined length of time by suction or partial vacuum. These sections separate while the ball is in the air after being thrown and release a parachute enclosed within and connected to the sec- No. 1,712,371, issued to Frank J. Wilkins. tions of the ball, so that the device will de- This device provides for the production of scend slowly to the ground. 4n elastic shadow letters or shadow figures and de- channel -shaped ring is located between the signs which may be used in the production sections of the ball, secured to one section of signs or lettering for any sort of print- and held to the other section by suction or ing or painting, by allowing the shadow to partial vacuum. One of the sections is fall upon the blank card upon 'which the provided with an opening to regulate the sign is to be painted. The device is placed passage of air. The two sections of the between a light source and a screen. The ball are pressed toward each other, and figures or letters are stretched across a when the pressure is released a partial frame on slender cords. vacuum is created. -

www.americanradiohistory.com 444 Science and Invention September, 1929 A Monthly Scientific Question and Answer Page Lightning Dual Ignition

(2323) J. B. Marlow, Atlantic City, (2324) O. T. Bausch, Manhattan, N. J., asks : Kan., asks : 1. the wir- Q. 1. What are the known types of The Q. Will you please publish lightning and how are they characterized? ing diagram of a double ignition system A. 1. Probably the most familiar type such as that used in the Stutz series R of lightning is streak lightning. Not classi motor cars? fled as distinct types, but variations of A. 1. On this page you will find illus- of the dual igni- streak lightning are the following : Rib- Oracle trated the wiring diagram bon, rocket and bead lightning. Forked tion circuit. The motors used with dual and zigzag lightning are also in- ignition system have two spark cluded. Other types more rarely plugs per cylinder. The Stutz observed are ball or globular LEFT HAND engine is a dual valve engine, LEFT HAND RIGHT HAND IGNITION COIL with intake valves on one side of lightning and sheet lightning. DISTRIBUTOR (DISTRIBUTOR Streak lightning exhibits a the cylinder, and exhaust valves white or pink path of rather on the other. There are two spark small diameter, from an inch to g plugs per cylinder, one on the in- a foot, and up to a mile in length, take side and the other on the ex- depending upon the conditions of haust side. In the illustration the discharge. In many cases the 1 these spark plugs are marked path is sinuous and forked, in left -hand and right -hand plugs. others it appears as a single GND The ignition primary circuit (left -hand coil) is as follows: streak. The discharge may take Y v oo place within a cloud, between RIGHT HAND From the positive (ground) of separate clouds, between clouds /gyX p IGNITION COIL the battery, if starting, or ground and the earth, or between a cloud of generator, if generator is run- and surrounding air. L.H. SPARK R.H. SPARK ning at proper speed, to ground Occasionally a flash or streak PLUGS PLUGS of contact breaker points, of lightning assumes the form of through points, through ignition a number of parallel streaks c o resistance, through primary coil, called "ribbon lightning." Most L.H- BREAKER R.H.BREAKER. to switch, to ammeter. The igni- streak discharges consist of sev- tion primary circuit for the right - eral successive discharges, with The wiring diagram of the dual ignition system is shown hand coil is exactly the same as each an appreciable time interval be- above. Two sets of spark coils are employed in that for the left -hand coil, ex- cylinder. tween them. In the intervals be- cept that the contact breaker tween discharges the path may points for the right -hand coil are be shifted by the wind. Thus, several clouds and haze. This constitutes a dis- at the lower part of the interrupter. The successive discharges displaced by the tinct type of lightning. Such discharges secondary circuit from the secondary coils wind may appear as parallel streaks due to are somewhat similar to a brush discharge of both spark coils can be traced to the the persistence of vision. and are usually of white color. The dis- center terminal of the distributor to the Rocket lightning is a term applied to charge appears to occur as a sheet, al- spark plugs, to ground, and so on to the streak lightning discharges, the growth of though it is more likely a volume effect. other end of the secondary winding. which is so slow as to appear like a rocket. It is distinguished from the aurora by the Bead lightning is that form in which fact that it takes place in the cloud layers, Dermatitis from Oil the path of the discharge appears as a while the aurora is only observed in the string of luminous globes or beads, sepa- rarefied upper atmosphere. The name (2325) T. C. Novak, Pasadena, Calif., rated by darker intervals. Several ex- sheet lightning is falsely given to the writes : planations are given for this form of illumination arising from streak lightning, Q. 1. Several men working in a ma- lightning. One is that it is due to varia- the source of which is visible clue to cloud chine shop and handling lubricating oil tions of the path of the discharge with banks or because the discharge takes place used for cleaning and rust removal, have respect to the line of sight. Another holds below the horizon and is so distant that the acquired what seems to be a skin disease that the striae of haze obscure portions of thunder either comes too late, to be asso- of the hands. The oil has an odor similar the path. A third is that it is a combina- ciated with the illumination, or cannot be to wintergreen and is of a purplish color. tion of streak and globe lightning. heard at all. Sheet lightning is distin- A. 1. The type of oil mentioned is Forked lightning refers to the branching guished by its persistence and comparative- known as "penetrating oil" and the basic of the streak discharge at its lower end in ly slow variation of intensity. ingredients are kerosene, benzine, benzene some cases. Two or more objects are and paraffin oils. These may be employed often struck at the same time by the forks. singly or in various combinations. A The term zigzag lightning is applied to heavier lubricating oil in small quantities The "Oracle" is for the sole benefit of is usually added. In order to be patent- streak discharges which assume an ex- all scientific students. Questions will be tremely sinuous path. Such discharges answered here for the benefit of all, but able, these oils may contain special agents only matter of sufficient interest will be pub- such as phenols, cresols, toluene, coloring present entirely different appearances from lished. Rules under which questions will different points of observation. be answered: agents and deodorants. According to the Globular lightning is a discharge which 1. Only three questions can be submit'.ed Journal of the American Medical Associa- consists of luminous globes, or ball -shaped to be answered. tion, dermatoses may be expected from the masses which are seen to move along the 2. Only one side of sheet to be written use of any penetrating oil or similar lubri- on; matter must be typewritten or else ground, or through the air. These globes written in ink; no penciled matter con- cant. This may be due in part to the defat- sometimes explode with a loud report and sidered. ting of the skin, which property is shared serious damage. It is a brilliant 3. Sketches, diagrams, etc., must be on by substances such as gasoline, benzene and cause separate sheets. Questions addressed to this brush discharge moving along a path of department cannot be answered by mail free turpentine. In part, dermatoses may be the low dielectric strength in an electric field of charge. direct results of chemical burns from of a storm. This discharge probably pro- 4. If a quick answer is desired by mail, a irritating agents found in the oils. nominal charge of 50 cents is made for each ceeds or follows streak lightning, immedi- question. If the questions entail consider- Phenols, when present; may produce sys- ately. This would account for the appar- able research work or intricate calculations, temic poisoning from skin absorption. a special rate will be charged. Corre- ent explosions. spondents will be informed as to the fee Aldehydes and particularly acrolein are Sheet lightning is a term applied to before such questions are answered. detectable in this type of product and may silent discharges occasionally observed in contribute to the cause of skin lesions.

www.americanradiohistory.com September, 1929 Science and Invention 445 FREE PROOF YOU CAN MAKE BIG MONEY "ILADIOT

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www.americanradiohistory.com 446 Science and Invention September, 1929 How the Stock Exchange Works T'S a far cry How Brokers Execute Orders pose in 1792, may from the launch- rightly be regarded ing of the Amer- as the nursery ican republic up By Alfred M. Caddell wherein American to the present ; from Financial Editor industry has been the days of the canal - cultivated. For with- boats and Indian out liquidation fa- trails up through the early railroad and cilities, the sale of securities, no matter telegraph era to the telephone, the elec- how promising, would have been an impos- tric light, electric and gasoline motors sibility. Railroads, the telegraph, the tele- and the radio age. And it is an equally phone, manufacturing, public utilities, long story from the year several men gath- mining and the other vast enterprises with ered under an old buttonwood tree in front which we are now familiar, could never of what is now 68 Wall Street, New York, have been launched and built into dividend - to establish a market for the buying and payers without the facilities of sale of- There's the Man Who's selling of securities. fered by the Stock Exchange. An out- In the year 1790, the first Congress of growth of industrial ambition supported by Holding You Down the United States authorized the issue of public financing, it is at once a financial mirror of the public's investment desires Yes, sir! There's the man. You see him every $80,000,000 in bonds, which were promptly time you look in the mirror. His name isn't taken up by investors. About the same and a clearing -house of security values. Brown or Smith or Jones, but Y -O -U. He's your time three important banking institutions To conceive of the workings of the real boss. He's the man who decides whether sold to Stock Exchange in the days of the old your salary will be $35 a week or $100 or $150. were incorporated and their stock IF you want to get ahead there's just one sure way to do it -train yourself to do the day's work better than any other man in the office. Ability is bound to count. Your employer will be glad to pay you more money if you show him you deserve it. Left -The first "Stock Ex- A home -study course with the International Corre- change" in America. Under spondence Schools will prepare YOU for the position you want in the work you like best. All it takes is the old buttonwood tree an hour a day of the spare time that now goes to which used to stand in front waste. of what is now 68 Wall St. Write for Free Booklet

INTERNATIONAL CORRESPONDENCE SCHOOLS "The Universal University" Box- 6195F. Scranton, Penna. Without cost or obligation on my part, please send me a copy of your 48 -page booklet, "Who Wins and Why," and tell me how I can qualify for the position, or in the subject, before which I have marked an X: TECHNICAL AND INDUSTRIAL COURSES Architect Automobile Work Cl Architectural Draftsman Aviation Engines Ll Building Foreman Plumber and Steam Fitter Concrete Builder Plumbing Inspector Contractor and Builder Foreman Plumber OStructural Draftsman Heating and Ventilation Structural Engineer ® Sheet -Metal Worker Electrical Engineer Steam Engineer Electrical Contractor Marine Engineer Electric Wiring Refrigeration Engineer Electric Lighting CI R. B. Positions Electric Car Running Highway Engineer Telegraph Engineer Chemistry Cl Telephone Work Pharmacy Mechanical Engineer Coal Mining Engineer Mechanical Draftsman Navigation Assayer Machine Shop Practice Iron and Steel Worker Toolmaker Textile Overseer or Supt. Patternmaker Cotton Manufacturing Civil Engineer Woolen Manufacturing Surveying and Mapping Agriculture Fruit Growing Bridge Engineer Poultry Farming Gas Engine Operating Mathematics Radio BUSINESS TRAINING COURSES Right -The present home Business Management Business Correspondence of the .New York Stock Industrial Management Show Card and Sign Personnel Management Lettering Exchange at the corner Traffic Management 0 Stenography and Typing of Broad and Wall D Accounting and C. P. A. English Coaching El Civil Service streets, New York City. LICost Accounting Railway Mail Clerk Bookkeeping Iliad Carrier Secretarial Work Grade School Subjects Spanish French High School Subjects Salesmanship Illustrating Cartooning Advertising Lumber Dealer Name Street Address City State Occupation if yods reside in Canada, send this coupon to the International Correspondence Schools Canadian, Limited, Montreal, Canada

Left -The new stock ticker shortly to be installed in brokerage offices throughout the country. This ticker will work three times as Only 4 Motions used in playing this fascinating used. instrument. Our native Hawaiian Instructors fast as the ticker now being teach you to master them quickly. Pictures show how. Everything explained clearly. Playin Half Hour Easy Lessons After you get the Even if rou don't four sy motions know e note from 3,013 r harmonious another, ehotds very printed and little practice. clear pictures make learn not require much knowledgey+eeded. iy`aPayto ls play. the public. The sale of these securities buttonwood tree would GIVEN-sehen you enroll created a demand for a market in which stretch of the imagination. But the im- a sweet toned the purchasers could liquidate their hold- portance of the stock market commanded HAWAIIAN GUITAR, Carrying Case and a formal organiza- WRITE AT ONCE for attrac I and Playing Outfit ings for cash, if desired. And many people early recognition Live offer and easy terms. A of twenty -four will do. ACT! Value S28 to S20 did desire to dispose of what they owned tion with a membership Postcard No extraseverythseg included 1792. The War of OTHER Tenor Banjo, Violin. Tiple, Tenor Guitar, Ukulela, and invest in something else, so trading brokers was effected in COURSES Banjo Ukulele. Under well - known insteoetory. in securities began. 1812 resulted in the government offering FIRST HAWAIIAN CONSERVATORY of MUSIC. Ina. the, subsequent 9th Floor, Woolworth Bldg., Dept. 240 New York, N. Y. The establishment of this market in more bonds and this, with School the Laws 1790, to be administered by a rapid development of the nation, broadened Staff New York-Member aional Calmed. afterwards f formal organization effected for the pur- (Continued oit page 448)

www.americanradiohistory.com September, 1929 Science and Invention 447 No More Razor Blades To Buy!

365 Keen Shaves A YEAR WITH ONE SINGLE BLADE "I want to say that KRISS -KROSS Stropper is the best thing I ever saw. I have been using one blade continuously for one year and nine months and have no idea how much longer it will last." C. S. Stephenson, Okla. l wentor Discovers Amazing NewWay to Shave! -Without Buying Blades! EEN velvety shaves forever and no more But that's not all, KRISS -KROSS embodies zips right through the toughest crops of whiskers. blades to buy ! That's what the astonishing still another feature that has hitherto baffled Made of rustless metal. Comes with 5 special - K invention of a St. Louis man offers the great mechanical reproduction. It strops from heavy process blades and is entirely unlike anything you army of American shavers today ! to light. It's absolutely uncanny the way the ever saw before ! KRISS -KROSS is destined to revolutionize all strokes start with strong pressure and grow existing traditions ! of shaving Its performance is lighter and lighter until an adjustable, auto- Get Free Offer . so sensational that it seems hardly fair to call it matic jig flies up and notifies you that your blade a stropper. Rather it is a super- stropper or blade - is ready -ready with the keenest cutting -edge that Send for full information on these surprising rejuvenator! Almost literally it makes a new steel can take! new inventions today. KRISS -KROSS products blade out of an old one every day. No longer do are never sold in stores. You deal direct with me you find that your blades "die" after five or six Fits All Makes of Blades or my authorized representative. Write for illus- shaves. KRISS -KROSS "brings 'em trated description and full details of free razor to life" a surprising way, week after KRISS -KROSS produces unbeliev- offer. It's even more remarkable than I can tell week and month after month and enable sharpness and prolongs the life you in this short space. Clip the coupon now. dows them with a keenness that they of any razor blade for months and even Mail it today. never possessed when brand -new! Ac- years. Fits all brands and makes ex- tually you can take a blade right out Mystery cept Durham. Eliminates 83% of shav- of a fresh package and improve it as ing costs. No more "raking" and much as 100% in eleven seconds with Razor scraping with dull blades. No more KRISS- KROSS! No wonder experts stinging and smarting that has to be Agents $30.00 a Day pronounce it one of the greatest in- FREE relieved with messy lotions and harsh ventions ever patented! astringents. KRISS-KROSS solves Stake big money with KRISS- KROSS. Giving your blade problem for all time and away FREE razors boosts your profits amazingly. gives you keen velvet- smooth shaves TI. King made (66 in one day. N. C. Paige made Magic Diagonal Stroke $104 in 3 days! Others average $350 and up to forever ! $750 a month! Spare -time workers. Office and Fac- until you've seen KRISS- KROSS, fitted its tory men make $6 -$12 extra a day showing KRISS- sturdy nickeled smoothness into the palm of your Sensational Offer KROSS to friends and fellow employes. S. Kantala hand and tested its uncanny dexterity yourself, made $154 extra just working evenings 3 weeks. Get details at once. Cheek bottoni of coupon and you'll never know how amazing it really is ! It And now for my surprising offer. To introduce mail it today! employs the famous diagonal stroke, same as a KRISS -KROSS, I am giving with it Free a new master barber uses. Never before has anyone kind of razor. Possesses remarkable features. captured the secret of reproducing it automatic- Instantly adjustable to any shaving position. A ally. Eight "lucky leather grooves" do the trick flip of the finger makes it (1) T-shaped ; (2) in 11 seconds with a precision it takes a master straight (old style) ; (3) or diagonal (new way). KRISS -KROSS CORP'N, Dept. M.3104 barber years to attain. Gives a sliding instead of pulling stroke. Simply 1418 Pendleton Ave., St. Louis, Mo. Without obligation, please send me illustrated description and full details of your special intro - duetory offer on KRISS -KROSS super- stropper and FREE 3 -sway razor. Name I 'z ISS KRO Address gel( Canadian Address: Town KRISS -KROSS CORP'N CANADIAN KRISS -KROSS CO. Cheek here if interested in making money as Dept. M -3104, 1418 Pendleton Ave. 39 Wellington Street East authorized KRISS -KROSS representative. St. Louis, Mo. Toronto 2, Canada L J

www.americanradiohistory.com 448 Science and Invention September, 1929 How the Stock Exchange Works (Continued frotte page 446)

the scope of the securities market. In order. Telephone clerks are not permitted 1817, rooms were engaged at No. 40 Wall to leave their booths. Street and it was there that the first in- With your order in his hand, your broker door securities market in the United States must buy for you 100 shares of U. S. began to function under a constitution and Steel at as low a price as he can buy it for set of rules. in the market at that time. In a word, he Before the coming of the telegraph, all becomes your personal representative on offers to buy and sell were carried the floor of the Exchange and must act in THE between STEALTHY brokerage offices and the Stock Exchange your behalf according to his best judgment. TERROR by fleet runners, who also conveyed the In order to facilitate execution of orders, by latest quotations and market news. But the system of trading posts was established. A JOHN in 1867, an invention called the ticker rev- stock, such as Steel, is as- FERGUSON olutionized this primitive means and put signed, among others, to a certain post, security quotations on an instantaneous and there it may be found by any broker basis. interested in executing an order. Simi- The ticker was invented by a telegraph larly, each of the several trading posts operator by the name of E. A. Calahan, throughout the room is the market for who conceived the idea of transmitting the twenty or thirty different stocks. various sales taking place on the floor of On his arrival at the post designated for the Stock Exchange to brokers' offices by Steel, your broker hears this stock being electrical means. There are two parts to offered at, let us say, 142% ($142.25) He New this system -a transmitter on the floor of also hears another broker bidding 142% the exchange and a ticker or recording in- (142.12%) for it. Thus he is at once instrument in the office of the broker, which formed of the true market for the stock- records the various sales as they are made. $142.12% a share bid, offered at $142.25 a The transmitter employs the principle share. Detective of permutation control of a printing device As your broker has authority to buy the (the ticker) which is located in a distant stock for you "at the market," or at the office. Permutation control means control lowest price at which it can be had, he of that printer to bring about various com- says to the broker offering to sell at 142% Novels binations of a small number of units to (142.25) : "Take it," and the transaction control a large number of symbols and is consummated. No written agreement or figures. By means of the telegraph prin- memorandum of any kind is exchanged by ciple utilized in connection with a polarity the contracting brokers, the purchasing by Famous reverser, the transmitter causes the type broker making a notation on the form wheel of the distant ticker to rotate in bearing your order who sold it to him and synchronism with the typewheel of the at what price, and the selling broker mak- transmitter. The typewheel is made to ing notation on a pad who bought the stock Authors rotate back and forth by this system of from him, and the price. All contracts reversing polarity and come to a stop at a made on the floor of the Exchange, in- combination of the right letters from which volving in the aggregate, frequently up- symbols representing various securities and wards of three or four hundreds of millions figures representing various price combina- of dollars in a day, are made in this ap- 5 for $1 tions are composed. Thereupon the com- parently informal way, and yet such bined letters and figures become imprinted contracts are always held inviolable by on a paper tape, from which brokers and members of the Stock Exchange. Now just $1 brings all 5 of these new their customers may learn what is taking Your broker now sends to his telephone book-length Detective Novels (shown place in the market. clerk a memorandum that he has bought above) in the new magazine cover 100 Steel at 142/ from Broker So- and -so. form. The same stories that are being How Orders Are Handled The clerk promptly telephones the report sold in the book shops for $2 each - to his office, and it is telegraphed to the LET us suppose that you, John, and you, written by the most popular authors. Kansas City branch office where you are Edna, desire to buy 100 shares of U. S. Steel common stock. Let us waiting, and if you are watching the ticker America's greatest leaders read these suppose, you will see the following quotation ap- stories to also, that you live in Portland, Oregon, or stimulate and exercise their : X 142 Kansas City, Missouri these days pear /, which means a transaction minds. -in of of 100 of has taken place at electrical communication it makes no shares Steel dif- that price, X being the symbol for U. S. ference where you live so long as See if you can solve the strange epi- you Steel. If the transaction had been for 500 sode of the Marsh Murder. See if you have access to a ticker in a brokerage office or are shares, the ticker tape would read 5X can find out how a great American de- content to conduct business and so on. with a broker 142/, tective outwitted England's famous by phone or telegraph. We It has naturally taken quite a few words Scotland Yard. See if you can discover will assume, however, that you are sitting you in the to tell the story of the transaction set who murdered the beautiful Chicago customers' room of a broker's office in motion, but due to the efficiency with in Kansas and have heiress, and why. Make a single $1 City that you author- which your order is executed, it is possible ized your broker 100 fill your evenings with long hours of to buy shares of that the ticker will report ''he transaction fascinating, inexpensive pleasure. U. S. Steel "at the market," which means you have regained your seat in the at the then prevailing price. before Your broker's office. So swiftly are orders put MONEY BACK IF NOT SATISFIED order is recorded by a clerk and through that there are instances on record Simply pin transmitted over the broker's private tele- a dollar bill to graph where orders given in San Francisco have the coupon -mail it to address wire to his New York office. Here been executed on the floor of the Stock it is received, given, and we'll send you post- practically instantaneously, Exchange in New York, 3,000 miles away, paid all 5 novels complete. and turned over to a telephone clerk in and reported back to the customer within the New York house for transmission by Write today. one minute's time ! And since branch of- private wire to the floor of the exchange. fices and correspondents of Stock Exchange The floor telephone is MI, MIN=.1, situated in one of firms can be found in practically every city Ilia' the many booths set aside for brokers and I of size in the United States, it will be seen Novel Magazine Corp. is manned by clerks employed by the that the Exchange to all intents and pur- 381 Fourth Ave., Dept. 2509X brokers. New York, N. Y. poses succeeds in bringing to its floor, face As the telephone clerk receives your face, investors in the land interested Gentlemen: order over his telephone he to all jots it down in buying or selling listed securities. I enclose $1 to pay for the 5 novels shown on an order slip and at the saine time above. It is understood that I can return presses a button in his booth, which oper- them and get my money back if not per- Outstanding Features fectly satisfied. ates a number on the large annunciator board. This particular number has been THE buying and selling of securities ME assigned by the Exchange to the floor has long since entered the realm of Big E member of the brokerage firm with whom Business, but a few facts setting forth the Y STATE you are dealing, and upon seeing it the floor magnitude of this business may prove of k--_ member goes to his booth to receive your interest.

www.americanradiohistory.com September, 1929 Science and Invention 449

The membership of the New York Stock Exchange, for years restricted to 1,100. 66 has lately been authorized to total 1,375 memberships, or "seats," which at present are valued in the neighborhood of $500,000 each. best - The branch offices of these members, to- The paying taling 1,192, are to be found in nearly every state of the Union and in Canada, England, France, Hawaii and Cuba. For the year 1927 (since then the sum I ever made the value investment total has been greatly increased) of securities dealt in on the Stock Ex- change totaled $59,814,924,265.70. Stock and bond tickers in operation throughout thirty -five of the forty -eight -a 2c stamp" states number 7,916. Thus, thanks to the wonders of this electrical age, security traders in California or Washington may obtain the market quotations just as quickly WHEN I invest hundreds of as a broker whose office is next door to the dollars, I look for a safe Stock Exchange. return on my The Stock Exchange is open five hours seven per cent per day (two hours Saturday), and during money. I want dividends, and a those hours approximately 2,000,000 calls minimum of risk. The same thing are transmitted over the private wires connecting members' offices with the floor of applied when I decided to buy the Stock Exchange. There are about a car wanted dividends in 2,000 members' private wires to the floor -I and between 1,050 and 1,100 telephone pleasure and trouble -free per- clerks are engaged on the floor in handling formance, without too great a orders. The telephone booths on the floor of the risk. I saw this free booklet ad- Exchange are connected with the trading vertised, "How to Judge a Used posts for exchange of messages by a pneumatic tube system which contains 35 miles Car," and figuring that I couldn't of aluminum tubing and six 75- horse- go wrong for only a 2c stamp, I power compressors delivering 30,000 cubic feet of air per minute at 1% pounds sent for it. That 2c stamp has pressure. been the best paying investment On June 12, 1928, when total sales not only amounted to more than 5,000,000 shares lever made -because it (since then the day's record of sales has saved me about $200 on my car's reached 8,000,000 shares), approximately original cost but it told me how 17,500,000 feet of paper tape or 3,314 miles (enough to span the continent) were Pledge to the Public to buy a used car wisely!" used on the stock tickers alone. You will find the 2c stamp As of October 1, 1928, there were 1.513 on Used Car Sales bonds and 1,131 stocks listed on the New you use to get your free copy of York Stock Exchange. These had a mar- "How to Judge a Used Car"just ket value of $47,059,543,168 and $59,332,- Every used car is conspicuously marked figures, 123,511 respectively. 1 with its lowest price in plain as good an investment! It tells and that price, just as the price of our you trade secrets. It illustrates, New Stock Ticker new cars, is rigidly maintained. in 32 pages of interesting text SO great was the volume of business All Studebaker automobiles which are handled by the Stock Exchange during 2 sold as CERTIFIED CARS have been and pictures, just what to look 1928, that the machinery for handling the properly reconditioned, and carry a for in the used car you buy large number of security transactions fairly 30day guarantee for replacement of - creaked under the burdens imposed upon it. defective parts and free service on ad. what speedometer readings On various days the ticker service was all justments. mean, how to avoid "orphans," as far as recording transactions but useless Every purchaser of a used car may mean, how to was concerned. It was not unusual for the and then, if not what code prices to one hour 3 drive it for five days, ticker to be from half an hour for any reason, turn it back set a fair price on a used car forty - satisfied late -on one day it was one hour and paid as a credit it was and apply the money offered by a friend, and a host two minutes behind the transaction on the purchase of any other car in reporting. stock -new or used. (It is assumed of other important points in used To take care of big share days which damaged in fu- that the car has not been car buying. Send today for your will inevitably occur in the not distant the meantime.) ture, the Exchange has been experiment- free copy -spend 2e and avoid which is ing with a kind of ticker service a 1928 The Studebaker Corporation d America reported to be three times as fast as the $200 mistakes! one now in service. When finally installed, this instrument will be capable of a maximum speed of about 900 characters per with 300 characters on ' THE STUDEBAKER CORPORATION OF AMERICA minute as compared Indiana the ticker now in use. One of the prin- Dept. 179, South Bend, cipal improvements made in the new ticker Please send me copy of "How to Judge a Used Car" is that printing of the characters selected from the typewheel for impression -such I Name as GM 126 or TC 173/8-in accordance with the master tape cut by the operator of Street the transmitting apparatus, will occur simultaneously with the selection, instead of State the typewheel stopping after selection be- City fore printing, as at present. Financial Questions and Answers Edited by Mr.Caddell, Financial Editor Question -I own 200 shares of Timken S'UIJEBRKEA Roller Bearing. and would like your opinion on the future earning possibilities Builder of Champions of this stock. C. H. H., Chicago, Ill.

www.americanradiohistory.com 450 Science and Invention September, 1929

Answer-Timken Roller Bearing Co. enjoys the distinction of being the largest domestic manufacturer of tapered roller bearings, its equipment being used on about 90% of all makes of passenger automobiles, trucks and buses, including Fords. At present 116 steam railroads and 26 electric railways are using Timken bearings. The company owns steel and tube mills and sells a large part of its pro - Advertisements duction in this division to outside customers. Capital stock consists of 2,407,824 no- are a guide par shares. There is no funded debt and the formerly outstanding preferred stock was wholly redeemed in 1922. Present to value dividend rate on the new common is $3 a share annually, equal to $6 a share on the stock before the split -up last January, compared with a total payment of $5.25 in 1928, $5 in 1927 and $4.50 in 1926. Balance sheet as of Dec. 31, 1928, was exceptionally strong. In the first quarter EXPERTS can roughly estimate the value of a of this year the company reported net of $4,264,225, equivalent to $1.77 a share product by looking at it. More accurately, by on the $2,407,824 no -par shares of capital handling and examining it. Its stock. With motor production at record appearance, its levels, Timken's report for the three texture, the "feel" and the balance of it all mean months ended June 30 will undoubtedly be highly satisfactory. Steel production con - something to their trained eyes and fingers. tinues to remain at high levels, and inasmuch as farm purchasing power is large and railway equipment buying is on a satis- But no one person can be an expert on steel, factory basis, the outlook for this company brass, wood, would appear to be continuously prom- leather, foodstuffs, fabrics, and all ising. of the materials that make up a list of personal Question -What is your opinion regarding a purchase of New York Title & purchases. And even experts are fooled, some- Mortgage 5 /s? P. P. L., Chattanooga, Tenn. times, by concealed flaws and imperfections. Answer -New York Title & Mortgage 5/s are sound first mortgage certificates, There is a surer index of value than the senses backed by one of the leading title and mortgage companies in the field, with cap- of sight and touch . . . knowledge of the maker's ital and resources of more than $60,000,000. This company sells title insurance policies name and for what it stands. Here is the most which constitute the basis of sound mortgage loans. certain method, except of that actual use, for Question-I would like to have a report judging the value of any manufactured goods. on Credit Alliance Corporation stocks. C. H., Cheney, Kan. Here is the only guarantee against careless work- Answer -This company finances the sales and purchases of necessary indus- manship, or the use of shoddy materials. trial equipment, and is similar in operation to the General Motors Acceptance Corp., This is one important reason why it pays to buying equipment for manufacturers and permitting them to pay the purchase price read advertisements and to buy advertised goods. by means of monthly notes. On March 1, 1928, this company's entire The product that is advertised is worthy of your issue of preferred stock was called in at confidence. $110 a share. There are still some deben- ture bonds and equipment trust notes ahead of stock dividends, but the latter are being retired every six months and the company expects to retire them completely within titis year. The class A stock, of which there are 45,543 shares outstanding, pays $2 in dividends, which at the present market price yields a little better than 5.75%. The company is now in its biggest year, the first five months of 1929 being far STUDY AT HOME ahead of the similar period last year. The Become a lawyer. Legally trained securities of titis company men win high positions nd big would appear in busiueea and public life. to Be independent. Greater opportuni- offer a fair speculation. ties now than ever before. Big corpo- are headed by men with legal Question-I would thank you to give me raining.trations Earn information regarding oENTsTRY $5,000 to $10,000 Annually Cities Service Corn - M We you eton by atop. You can train at home dur- pany as a safe investment. B. C. H., St. Learn in few months to make plates, crowns, bridges, ing sparepare time. Degree of LL.B. conferred. LaSalle tuddente found a o g practicing attorneys of Joseph, Mo. etc.. for dentists. No books. Day or night schools in Mate. We furnieh all text material, including fourteen -volume Chicago, Detroit Cleveland Boston, Philadelphia. Imw Library. Low st, easy terme. Get valuable 64 -paer. Answer -The year 1928 was the most WRITE FOR FREE BOOK Law Guide" and "Evidence" books FREE. Send for them NOW. successful McCarrie School of Mechanical Dentistry LaSalle Extension University, Dept. 9384 -L Chicago year in the company's history. 1338 S. Michigan Avenue Dept. 305 Chicago, III, The World's Largest Business Training institution Large increases were made in assets, gross and net earnings, and also the number of security holders, who now total more titan M MYSTERY GAS LIGHTER M 450,000. Excess of current assets over r OUT LIGHTS INSTANTLY Amazing Discovery JUST GAS WITHOUT current liabilities increased 26.75%, from SPARKS OR FLAME SELLS LIKE WILDFIRE I positively guarantee to increase o WHEREVER GAS IS USED -RETAILS FOR 250 your arms one -half inch in size, $52,932,000 to $67,094,000. Consolidated o chest one full inch, strength 25%, net 1 MAKE $')S A DAY health 100% in one week's time, earnings of Cities Service and its sub - N N by following my instructions and sidiaries exceeded $64,000,000, equal to using my exerciser 10 minutes 9.43% on the total capitalization E PACKED l#11NDIVIDLWLCAN05 MIN INS/I{UCpONl -OM mornings and at night. Send $1 and for complete course and exercisers. R USN ea E funded debt. Total consolidated assets of ilO°° FOR GROSS ioOFOR DOZ. Satisfaction guaranteed or $1 refunded. Proof Free. this nation -wide organization increased Y NewMethedMfg.Co.,Box23-9,Bradford,Pa. Y Prof. .1. A. DRYER; But 1850 -L, Chicago,lll during the year front over $809,000,000 to

www.americanradiohistory.com September,. 1929 Science and Invention 451 more than $913,000,000; quite a growth. This stock recently underwent a 4 to 1 split -up and while the dividend policy on the 11ew stack has not been announced, it can be stated withreasonable certainty that the 6% in cash and 6% in stock paid on the old stock annually will be cut one - fourth, making the payment on the 24,000,- 000 shares now outstanding exactly the 1.? BELL same as that received on the old shares. ;!i!.1à11110,:P, nuI1.ni:.c At current market prices the stock yields 7929 only slightly less than 7 %. At the present market prices, however, the future of this stock has been somewhat discounted, a factor which influences the rise in value of the stock only and not its dividend earning capacity. Information on securities will be fur= nished readers of Science and Invention free of charge by mail and through these columns. A 2 =cent stamped, self= addressed envelope should be included in your letter. Address your inquiries to The Financial Editor, Science and Inven- tion, 381 Fourth Avenue, New York City.

THE BELL SYSTEM IS BUILDING AHEAD OF THE GROWTH OF THE COUNTRY

Hints on Flying a Glider By Henry Townsend (Continued from page 431) This is the telephone's job and goal can be towed along by a motor -boat on the flu fldvertisement of the water, the glider of course rising a fair distance above the water as the motorboat flmerican Telephone and Telegraph Company moves along. The advantage of using two ropes for launching the glider as shown in the diagram, lies in the fact that when the glider snaps into the air and is in free flight, as shown by the dotted lines in the diagram, THE United States is de- This outlay is required the ring attached to the two ropes and rubber cord will drop, but it will not fall veloping a new civilization. because the telephone is a on someone's head. The ring, by the way, The telephone is an indis- universal servant of this should be considerably larger than the hook so that there will be no question of its pensable element in it. The Bell democracy. Business uses it to cre- falling off. If so desired, a special release System is building ahead of the ate more prosperity. Homes use it dog and lever arrangement may be worked out by the glider constructor. A low - growth of this civilization. In 1929 for comfort and protection, for nriced glider which young boys of twelve the telephone budget for land and keeping friendships alive and en- to fifteen years of age can build at small cost and have a lot of pleasure with, as buildings is 54 million dollars, with riching life. Its general use enables well as learning the first steps in actual new buildings rising in 200 cities. each personality to extend itself flying, was "described with working drawings in the last issue of this journal. Pre- New equipment for central offices without regard to distance. vious to that there appeared complete work- will cost 142 millions; exchange The telephone ideal is that ing drawings of a professional type glider and blueprints of this larger glider are lines 12o millions; toll lines 119 anyone, anywhere, shall be able available. millions. The Bell System's total to talk quickly and at reasonable The two photos accompanying this article are very interesting, the smaller photo expenditure for plant and service cost with anyone, anywhere else. showing an American built glider, with en- improvements this year will be 559 There is no standing still in the closed fuselage, in free flight just after the launching ropes have dropped. The million dollars. Bell System. large photo showing a glider about to be launched, depicts the first glider made by the members of the German -American Glider Club of Chicago. Quite a few of the members of this club gained their practical glider experience in Germany. Mr. Joseph Steinhauser of Chicago was the designer of the particular glider shown in the picture. An illustration of a beautiful EarnMore Money glider trophy, as well as the cash awards 1 knef,. offered for glider flights, were described ea in California,, in the July, 1929, issue of this magazine. ' for Your Model Plane N40 ío75 a week Feather- weight airplane wood will make Men. in for Auto your model airplane fly better. Cut Don Sterling makes $75 a .reek. Victor Wright. Glider Builders ! 10e $60 eek Paul Driggs - IsNauso all sizes ready for building. Send of National training. l5í000.y, e for you. too, in California. ar ,ll will r t afew for instructive illustrated booklet explain- weeks as echa oelectncian salesmrntetcy If you have successfully to fill big pay jobs now open -$50 to $75 a week.' built ing all details on model airplane construc- Million dollar school established 1905, thousands and flown a man = carrying f su essfflgradua . ew method of practical tions, also for interesting informatiön on FREE shopctr u . glider, take some photos of it, the wonderful Balsa Wood and supplies EARN WHILE YOU LEARN and send them Auto Book Oar Ne employment service finds you a sW+a along with a de= for model airplane building. Write us to- m e jab, if yms wish. You can earn st hiey, learn. FREE! :i j`es Tsin, scription, to the Editor. delay. and ' NATIONAL AUTOMOTIVE day -don't only. AUitpostal orowlritetfor big free eighty -four page auto book, Dept.300-AE,4004 South Figueroa HAWK MODEL AEROPLANE CO. with 150 illustration- gives all fact,. Les Angeles, California 4944 Irvin,/ Park Blvd., Dept. 13. Chicago, Ill.

www.americanradiohistory.com September, 1929 452 Science and Invention PATENT ADVICE INVENTORS CONDUCTED BY JOSEPH H. KRAUS.

Protect Your Ideas In this Department we publish such matter Should advice be desired by mail, a as is of interest to inventors and particularly nominal charge of $1.00 is made for each HOW Send tor our Guide Book, to those who are in doubt as to certain patent question. Sketches and descriptions must TO GET A PATENT, and Evidence Only one side of sheet of Invention Blank, sent Free on phases. Regular inquiries addressed to be clear and explicit. request. Tells our terms, methods, "Patent Advice" cannot be answered by mail should be written on. etc. Send model or sketch and free of charge. Such inquiries are published NOTE :-Before mailing your letter to description of your invention for readers. If the this department, see to it that your name INSPECTION and INSTRUCTIONS here for the benefit of all FREE. TERMS REASONABLE. idea is thought to be of importance, we make and address are upon the letter and envelope BEST REFERENCES. it a rule not to divulge all details, in order as well. Many letters are returned to us to protect the inventor as far as it is possi- because either the name of the inquirer or ble to do so. his address is incorrectly given. RANDOLPH & CO. Perpetual Motion as yet been devised in which the axe is Dept. 172, Washington, D. C riveted to the handle, with the exception of (1184) Charles C. Laney of Fair Play, the steel axes. However, these axes are Mo., suggests a system for attaining per- not employed in preference to the wooden petual motion which comprises an auto- Name handled ones, because of the concussive mobile, which moves back and forth on a effect which the steel construction pro- track. The track is supported on a ful- duces on the hands of the user. Street crum at its center so that it will teeter back You will note that practically any axe and forth. A pendulum hangs from the you, have used slides on the wooden por- center of the track. A spring at either City tion. If the head were pinned to the end is supported to facilitate the action of handle either the handle or the pin would. the machine. He asks our opinion. suffer. A. 1. One can no more expect that a We advise no action in this case. pendulum with a shifting weight will operate longer than an ordinary pendulum, than one can expect to get something for Toaster PATENTS analyzed, nothing. In your device, when (1187) George N. Buntin, Hermitage, one finds merely a pendulum which works Tenn., asks whether he could secure a MUNN & CO. back and forth combined with which there patent on a toaster, the nature of which is a shifting weight. Just as much energy PATENT ATTORNEYS he does not disclose, and which is to be is required to compress the springs as marketed for five and ten cents store trade. Aseociatert since 18 46 ieith the Scientific American give when they rebound, those springs will A. 1. An electric toaster is not ordi- in such actions. AMER. BLDG. minus a few losses inherent narily a patentable article. While a design SCIENTIFIC per- Washington, D. C. As a consequence, your machine for patent is possible on such a toaster, the SCIENTIFIC AMER. BLDG. petual motion will come to rest within a 40th St., N. Y. C. basic idea consists of a wire which is 24 -26 West few seconds after it has been started. TOWER BUILDING - Chicago, Ill. heated by means of electrical current, a built, if you HOBART BLDG., San Francisco, Cal. The system is so easily that grid which prevents the piece of bread con- VAN NUYS BLDG., Los Angeles, Cal. doubt our word you can proceed to from tòuching the wires and some means struct it and see for yourself the absolute of supporting both the wire, grid and the Books and Information on Patents impossibility of obtaining motion in this and Trade -Marks by Request whole contrivance. fashion. We doubt if you will have very much All Foreign Countries Associates in difficulty in manufacturing the product Talking Home Movie provided that it is different enough from the market. But unless the (1185) George N. Buntin, Hermitage, others on is divided into two or three parts, Tenn., suggests a method of connecting a article it be difficult for you to phonograph with a small movie camera, a we believe will PATENTS sell same at a profit in the stores to the BOOKLET FREE HIGHEST REFERENCES microphone and an amplifier for the pur- PROMPTNESS ASSURED BEST RESULTS which you intend to offer it. Send drawing or model for examination pose of making talkie movies at home. and advice. A. 1. The idea which you have ad- WATSON E. COLEMAN, Patent Lawyer 724 9th Street, N. W., Washington, D. C. vanced for a combination movie and Sign Painters' Guide new and we are quite Phonograph, is not (1188) Victor Elder, Pittsburgh, Pa., not secure a basic confident that you could has designed a sign painters' guide and part is now patent thereon. The talking asks whether he should patent it. in any store catering to the obtainable A. 1. We do not see any material ad- PATENTS wants of the movie enthusiast. WWWRITE FOR FREE INSTRUCTIONS vantage in the sign painters' guide, which no further action on Send drawing or model for examination. We would advise you have built. While it is possible that CARL MILLER, Patent Attorney suggestion. Former member Examining Corps, U. S. this you might be able to secure a limited Patent Office market on a device of this nature, it is 261 McGill Building, Washington, D. C. Axe Head Fastener extremely doubtful that patenting the (1186) Henry L. Ledoux, New Orleans, product will result in material gain from La., asks whether it would be worthwhile a financial standpoint. TORS'MODELS' to patent an idea in which a pin or rivet is There is nothing to prevent someone your idea and also labor Saving driven through an axe -head and through else from duplicating pecialists handle so as to prevent the axe -head placing that on the market. 20 years. Rendering Machinery. the ion ptete Service to from coming off. Protractors with levels thereon are old the man with IlesignedtBuilt 1. have been made to se- and have been known for many years. The - Guarantee -Free A. Attempts Circular -References by placing slightly different shape which you give BERNARD &HELIER -'31 East17th St.,NY.C. cure axe -heads to handles screws and rivets laterally through the your protractor will not constitute a basic To Insure your copy reaching you each axe and handle. patent claim. month, subscribe to SCIENCE AND INVEN- The difficulty is that the pins shear off We advise no action on the above TION, $2.50 year. Experimenter Publications, handles are destroyed. No axe has mentioned idea. Inc., 381 Fourth Avenue, New York City. or the

www.americanradiohistory.com September, 1929 Science and Invention 453

At the right is a view of my drafting and specification offices where a large staff of experienced experts are in my constant employ.

All drawingsand spec. My Law ifications are prepar- Patent ed under my personal Offices supervision. Just Across Street From U.S. Pat. Office V Protect Your Ideas Take the First Step Today- Action Counts Inventors if you have a useful, practical, novel idea for any new article or for an improvement on an old one, you should communicate with a competent Registered Patent Attorney AT ONCE. Every year thousands of applications for patents are filed in the U. S. Patent Office. Frequently two or snore applications are made for the same or substantially the same idea factizene, (even though the inventors may live in different sections of the country and be entirely unknown to one another). in such a case, the burden of proof 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 offices are directly across the street from the U. S. Patent Office. We understand the technicalities of patent law. We know the rules and requirements of the Patent Office. We can proceed in the quickest, safest and best ways in preparing an application for a patent covering your idea. Our success has been built on the strength of careful, efficient, satisfactory service to inventors and trademark owners located in every state in the Union. Strict Secrecy Preserved -Write Me in Confidence All communications. sketches. drawings, etc., are held in strictest confidence in strong. steel, fireproof files, which are accessible only to author- staff. Feel free to write me fully and frankly. It is probable ized members of my and get that I can help you. Highest references. But FIRST -clip the coupon my free book. Do THAT right now. No Charge for Information On How to Proceed The booklet shown here contains valuable information relating to patent procedure that every inventor should have. And with it I will send you CLARENCE A. O'BRIEN my "Record of Invention" form, on which you can sketch your idea and establish its date before a witness. Such evidence may later prove valu- Registered Patent Attorney able to you. Simply mail the coupon and I will send you the booklet, and and Attorney -at -Law together the "Record of Invention" form, with detailed information on how & Commercial Bank Bldg. to proceed and the costs involved. Do this NOW. No need to lose a 53 -V Security Savings minute's time. The coupon will bring you complete information entirely WASHINGTON, D. C. without charge or obligation. -or- Suite 1106, Woolworth Bldg. NEW YORK CITY Clarence A. O'Brien Please send me your free book "How to Obtain a Patent," and your `Record of Invention" form Registered Patent Attorney without any cost or obligation on my part. Member of Bar of: Supreme Court of the United States; Court of Appeals, District of Columbia Supreme Court, Name District of Columbia; United States Court of Claims. PRACTICE CONFINED EXCLUSIVELY TO 4 Address PATENTS, TRADEMARKS AND COPYRIGHTS 1 (Important! Write plainly and address office nearest you)

www.americanradiohistory.com 454 Science and Invention September, 1929 Is a College Education Worth While? Views `of Frank Melville, Jr. PATENTS (Continued from page 418) TRADE -MARKS muscles and tendons which are to be called fulness which wasn't necessary in college. upon to function at the right moment and The college which develops these character- Service istics in go a long way to Without charge or obligation, we in the right way, require training, pains- its students will will inform you on any questions you taking preparations. That is the physical make its graduates successful in business. may put to us touching on patent, side. The man who leaves college thinking he trade -mark and copyright law. You need identical You has learned everything generally finds that may ask: "Should I protect myself Our minds training. by patent, or register under the can probably take more out of the brain in the field of business he has learned trade -mark or copy -right laws? What than you put into it, principally because of nothing. kind of a patent should I obtain ?" its faculty of putting things together and and many other questions that may occur to you. These are vital points multiplying the number of its products. But to consider and questions will be it must be nourished and exercised. It must cheerfully answered. be fed with sound, basic facts, with the What Edwin Franko Goldman, Evidence of Conception best standards in all things ; with the ob- Famous Bandmaster, Thinks Before disclosing your invention to ligations of life and the conventions which anyone send for blank form, "EVI- we all are better off for observing. (Condoned from page 419) DENCE OF CONCEPTION," to be Many ambitious young men have asked signed and witnessed. As registered is experience, integrity, common-sense and patent attorneys we represent -hun- me what constitutes true happiness in busi- dreds of inventors all over the United ness. This is perhaps easier to answer in- personality. States and Canada in the advance- directly by defining what true happiness is Some of the world's greatest men, both ment of inventions. The form, "Evi- not. The millionaire isn't happy because in the business world and in the world of dence of Conception," sample, in- letters, structions relating to obtaining of he is a millionaire ; he's happy in spite of arts and were not college bred. patents and schedule of fees sent it. So my idea is that if an individual puts They were students by nature, acquiring upon request. his whole heart in his work, doesn't worry, knowledge and information from each and LANCASTER & ALLWINE but concerns himself solely with doing a everything with which they came in con- 270 Ouray Bldg., Washington, D. C. better job than the other fellow ; if he does tact, and having the capacity to grasp and Originators of forms `Evidence this without continually asking himself, retain any and everything worth -while. of Conception" "How much am I going to make out of Such men have vision and judgment, and this ?" that chap is going to awaken some have a natural aptitude for assimilating day to the fact that he is earning a lot of knowledge. They are "self-made"-"self- money ! taught." Happiness consists in being busy, being If my son were bent on a business career, A `This Needed InventionPaid content and being well. Money doesn't fig- I should feel that a college education was ure in it at all. My own idea was to regard not necessary for him. Inasmuch as he is business- life! -as a game. I wanted the not to follow a business career, he is at $135,000 best value in my merchandise; wanted the present at college. A YEAR. Beverage manufac- As for my own career, I graduated from turers immediately adopted best store first in the block, then in the this simple crimped tin cap. section, then in the city. I wanted to do public school and did not even have the Vii This invention would have the biggest volume of business and strove opportunity of attending high school. My made you independently wealthy. Fortunes success has been achieved through the await inventors working along right lines. Con- to have the most satisfied customers. The centrate on things that are NEEDED. Get Ray- question of money was one I figured would school of experience. mond Yates' new book. take care of itself. As I said before, a college education is "1000 NEEDED INVENTIONS" always a desirable not a Costs only $1.50 and may lead to a big idea. Find out My precepts in merchandising? I believe thing, but always what industry needs and the public wants. That's where I can make them clear in a single para- necessity. the money is ! Mr. Yates' book tells you what these things are. Send no money. This revised 1929 edition contains graph- valuable chapters on Aviation and Television. Just write Try always to sell a better product at a postal. Pay mailman $1.10 plus postage when book arrives. Your money back if you want it. This offer limited. write better price than the customer can get any- now and get on the right track. (Outside U. S. $1. 70 rash where else. In buying, practice the same What Prof. T. N. Carver Says with order. ) BUREAU OF INVENTIVE SCIENCE rule. Buy so that the seller can make a (Continued from page 419) 79 Wisner Building Rochester, N. Y. profit, too. Maybe it will be only a small NEW YEAR - NEW IDEA one on the individual purchase, but on large work that one might do. To seek an edu- PATENT YOUR IDEAS orders it will mount up. This keeps both cation with a fairly definite idea as to what Call or send me a sketch of sides contented and happy. the world needs, even though the world is your invention. Phone LONgacre 3088 You might call it the practical application willing to pay well for it, harmonizes per- FREEInventors Recording Blank of the Golden Rule in business. It has fectly with a social purpose. The fact that Confidential Advice been our cardinal principle from the time a young man with high ideals will be well U. S. and Foreign Patents secured by example, Reg.PatentAttorney our first store was founded. For paid for his work need not deter him, pro- Z.H.POLACHEK Consult. Engineer when we sell a customer a pair of shoes vided the work is useful. Of course, he MN 1234 Broadway, New York MR for four dollars, we consider that we are does not need to spend his high earnings making him a present of a dollar. And in selfish indulgence. There are too many when you realize that we sell 7,000,000 pairs opportunities to reinvest them in produc- of shoes a year you can appreciate the sav- is As one of the oldest patent tive industries, which also social service, firms in America we give ing we enable our customers to make. to permit one easily to adopt a life of Inventors at lowest consistent charge, a service noted passive enjoyment. forPATENTS results, evidenced by many well -known Patents of extra- The study of economics, for example, Patent -Sense, free. of ordinary value. Book, The Opinion W. O'Neill may have a definitely vocational purpose. Lacey & Lacey, 644 F St., Washington, D. C. Estab. 1869 (Continued from page 419) There is a large and growing demand for well trained economists, not only as teach- of history, the arts and sciences broaden a ers, hut in business as well. Business be- man's viewpoint and enable him to meet comes a more and more intellectual calling INVENTORS the problems into which his larger sphere as civilization advances and the industrial of influence brings him. While he is at- system becomes more and more complicated. in- We have been in business 30 years. If your so neces- Problems of investment, of valuation, of vention or patent has merit, send details or tending college this doesn't seem model, or write for information. Complete sary but once he has attained this education co- ordinating the factors of production, of facilities. References. and has entered a business life, the ever - forecasting business tendencies, are not ADAM FISHER MFG. CO. increasing value keeps unfolding in the field solved by men whose chief qualification is 205 -D St. Louis, Mo of business. the ability to "hustle." They are solved To my mind the college education helps by men who have a grasp of facts and prin- 11B 117TÉß CHARGING, a man more after he has attained success ciples and the ability to think about them. than it does in the actual attaining. to distinguish the relevant from the irrele- Only $16 Monthly The bright, intelligent college graduate vant facts in a situation, and to see what Start your own big business now. Small payments brings complete who lets his education stop with his diploma principles apply to the problem in hand. outfit for recharging auto and radio batteries. Easy terms. can never equal the man who recognizes This grasp of facts and principles may, Moneyback guarantee. Write to that in the field of business there is a still of course, be acquired without a college HOBART BROS. CO. greater university for Isis continued educa- education. So also may the facts and prin- Box Troy, Ohio 599, tion. He must keep studying and show a ciples of law, of medicine, of engineering tn CLEARS $ I50 ^ OO PROFIT' certain amount of originality and resource- (Continued on page 465)

www.americanradiohistory.com September, 1929 Science and Invention 455 Dunninger's Sensational Buzz -Saw 'Illusion (Continued from page 395) Attention is now called to the buzz -saw, which stands on a specially built platform and skeleton stand contrivance. The saw OUR OFFER is rotated by a powerful motor. The saw For Me Protection of Your Invention is put in Qperation and at the same time assistants, operating the drum slowly, set YOUR FIRST STEP - The in- the sane into motion and to the surprise, ventor should write for our blank horror and mystification of the entire form "RECORD OF INVEN- audience, the box containing the lady is your in- seen, slowly but surely, inch by inch, to TION." Before disclosing approach the whirling circular saw. vention, a sketch and description At last the box comes in contact with should be made on the blank sheets the buzzing saw and as the box continues of our "RECORD OF INVEN- to slowly slide along the skeleton tracks inventor of the platform, the saw whirls its way, TION" and signed by the buzzing loudly, through the box. When and witnessed, sent to us, and we kfl'' the box is in the position indicated in the :TTs . amount - will place it in our fireproof secret diagram, the slaves are ordered to stop OUR 1,1 6tF files. WE WILL ALSO GIVE while the magician closes the top of the - inven- box, covering the girl's head completely. OPINION as to whether the Then the command to proceed is again tion comes within the Patent Office given. The box is now completely sawed definition of a patentable invention. in half lengthwise ... a feat never before, This "Record of Invention" will in the annals of magical history, accomplished by any magician the world has serve as "proof of conception" until ever known ! VICTOR BUILDING the case can be filed in the Patent The box is then pushed back to its Our New Building, Nearly Opposite U. S. Office. THERE IS NO CHARGE former position, after committeemen make Patent Office, Specially Erected by Us OR OBLIGATION FOR THIS a thorough examination, proving to their for Our Own Use own as well as the audiences' satisfaction SERVICE. that the box is completely sawed through; Write for Our Five Books Mailed Free to Inventors the box is then opened, the lady is freed of her manacles, brought out of her hyp- Our Illustrated Guide Book notic trance by the performer and she HOW TO OBTAIN A PATENT trips daintily to the footlights to take her Contains full instructions regarding U. S. Patents. Our Methods, how. Terms, and 100 Mechanical Movements illustrated and described. Here is a problem to tax the mind of the cleverest thinker. OUR TRADE -MARK BOOK Shows value and necessity of Trade -Mark Protection. Information re- How can it be done? garding TRADE -MARICS AND UNFAIR COMPETITION IN TRADE. That's what we want our readers to conjecture upon. OUR FOREIGN BOOK One hundred dollars in gold is the re- We have Direct Agencies in Foreign Countries, and secure Foreign ward for the ingenious brain who offers Patents in shortest time and at lowest cost. the most workable method. We have in PROGRESS OF INVENTION our safe the blueprint and correct modas Description of World's Most Pressing Problems by Leading Scientists operandi written and sketched by Dun - and Inventors. ninger, but we want you, our readers, to develop a solution to this sensational Delays Are Dangerous in Patent Matters buzz -saw illusion. WHEN THE INVENTOR WISHES THE APPLICATION FILED WITHOUT DELAY, HE SHOULD HAVE HIS CASE MADE SPECIAL IN OUR OFFICE to secure protection, save correspondence and secure early filing date in Patent Office. He should send us a model, sketch or photograph, with a description of his invention together with $25.00 $21,000.00 FOR on account. We will make an examination of the U. S. Patent Office records to learn whether the invention is patentable. If SPIRITS it is we will prepare the official drawings immediately and forward them for approval and execution. If the invention is not patentable we will return the fee less the cost for the search. $1,000.00 offered by this publication for spirit manifesta- Payment of Fees in Installments It is not necessary that the total cost of a patent be paid in one payment. tions which cannot be dupli- Our custom is to permit our clients to pay for their applications in three installments as the preparation of the application progresses in our office. cated or explained by scien- Our Large, Comprehensive Organization has been established for 30 years and offers Prompt, Efficient and PERSONAL SERVICE by experienced tific means. Patent Lawyers and Draftsmen. Every case is in charge of a Specialist. Our Lawyers practice in all U. S. Courts and defend clients in suits involv- ing Patents, Trade -Marks and Copyrights. ALL COMMUNICATIONS AND DATA strictly Secret and Confidential. We shall be glad to have $10,000.00 for spiritual phe- you consult us or to answer any questions in regard to Patents, Trade - nomena offered by Joseph F. Marks or Copyrights without charge. Rinn. Highest References- Prompt Service -Reasonable Terms $10,000.00 offered by Joseph Dunninger for manifestations i which he cannot explain or FREE ; VICTOR J. EVANS & CO. duplicate under identical con- COUPON Registered Patent Attorneys Established 1898 : 715 Ninth St., Washington, D. C. ditions. MAIN OFFICES BRANCH OFFICES: 1007 Woolworth Bldg., New York City; 828 Fidelity Phila. Trust Bldg., Philadelphia, Pa.; 1640 -42 Conway Bldg., Chicago, Ill.; 514 Empire Bldg., Pittsburgh, Pa.; 1010 Hobart Bldg., San Francisco, Calif. Total: $21,000.00 now of- Gentlemen: Please send me FREE OF CHARGE your books as described above. fered. Name Address

www.americanradiohistory.com September, 1929 456 Science and Invention and Lewis A. Yancey. The average speed Stereoscopic Movies with was 107.2 miles, the date July 9th. They in the later completed the trip to Rome. Color and Voice Meanwhile in California Pilots Loren 62(CELLO Making W. Mendell and R. B. Reinhart broke the Radio Consoles new refueling record established a week By H. Winfield Secor previously by the Cleveland fliers and (Continued from page 405) listed. Their time was 246 hrs., 43 mins., and George K. Spoor, and P. John Berggren made in a plane named The Angeleno, of the Essanay Studios of Chicago. The powered by a Wright Whirlwind motor. notion pictures can be produced in color They landed on July 12. and are synchronized with sound. The pictures were projected on the world's larg- Radio Oracle was variously est screen the size of which (Continued front page 441) given of 48 feet wide by 26 feet high to 52 feet wide by 30 feet high. The pictures acid battery. In 1925 the U. S. Bureau of could have been projected on a screen 70 Standards tested a number of preparations feet wide. advertised as substitutes for the usual elec- As will be noted, the film itself is four trolyte and published their findings in a times the size of an ordinary film and as bulletin. Their report stated that changing a consequence the picture from it can be the solution in a storage battery does not projected on a screen 4 times as large charge it. Tests have shown that batteries as ordinarily employed without enlarging containing these solutions, contrary to the the grains of silver more than at present. claims made for them, behave in accord- A noteworthy advance is made in the ance with well -established laws of electro- attempt at getting the three dimensional chemistry. Comparison was made between effect. This was explained by Mr. Berg - batteries containing these solutions and gren in the following way. If you hold batteries containing electrolytes of sul- your two hands in front of you and raise phuric acid of equivalent strength. No the index finger of both hands, and if you essential differences were shown in the look at the index finger of the hand nearest charging, the voltage, the efficiency or the your eye, the index finger of the hand temperature. It takes as long to fully furthest away will appear double. If in- charge a battery containing one of these stead, you look at the distant finger, the solutions as to charge a similar battery A beautiful Walnut Cabinet with sliding one closer to your eye will appear double, containing the ordinary electrolyte. doors of matched Butt Walnut and but if you look midway between the two Although the materials and coloring selected Japanese Ash sidepanel overlays. fingers both of them will appear double. matter considered individually may be Accommodates Buckingham, Crosley, At- It is on this basis that the new camera harmless, the disadvantages in using such water Kent, Fada, Sparton and all stand- was developed. An object or a person is solutions more than offset any temporary - ard receivers. Ample space for Receiver, from two different points, Speaker, etc. photographed gain. The usual electrolyte of pure sul- the lenses of the camera being separated by phuric acid and water, adjusted to the Write today for Free illustrated folder of a distance of approximately 4% inches. proper specific gravity at the completion all neto styles, including Phono - Radio Each of these lenses transmits a different of a full charge, is believed to be the best. Combination Consoles. view of the object, and as a consequence EXCELLO PRODUCTS CORPORATION the shadows photographed on the film are The Truth About Gasoline 4832 West 16th St., Cicero, Illinois slightly different. Instead of using two frames for a picture Savers as has been the practice heretofore, in any attempt at stereoscopism the inventors per- By George A. Luers same frame ELECTRIFY YOUR fectly align the pictures on the (Continued from. page 422) x`685 of film and in that way get the shadow FOR ONL variation spoken of in the hand experiment. manifold at right angles to the mixture, RADIO COMPLETE Because of the fact that patents of the diluting and agitating the same into a Why discard your present good set when you system are now pending and it was not uniform desirable condition. As will be can electrify it for only $6.85, and banish the obvious, this air adds volume to the gas annoyance and expense of buying new e`B" desirable to release the details for publica- batteries? tion, the diagram appended to the text of mixture, reducing the quantity which must OVEll 100.000 TOWNSEND this article is not exactly accurate but it is pass through the carburetor and conse- "B" POWER UNITS IN USE quently results in saving fuel. Hooked up in a few minutes. schematic enough to give an idea of what Use same tubes -no changes. goes on in the camera. As will be seen Illustration (C) is a device of similar You'll be amazed at the im- characteristics, manufactured by the J. A. provement in reception and a picture of a circular object is being taken. distance getting. Send name The lenses of the camera are 4/ inches Stransky Manufacturing Co. This is a and address today for full device, ad- details, proof and Free Trial apart, and while prisms are used in the manifold but with valves and Offer. original construction to direct the rays of justments for individual fitting to the needs cf the car to which it is to be attached. TOWNSEND LABORATORIES, light upon the film, and to make the two 725 Townsend St., Chicago, Ill. views register on top of each other, we have As will be noted by comparison with the Please send me full information on the Townsend hand in the illustration, this device is com- "B" Power Free Trial chosen to use reflectors and a half silvered and Offer. mirror to explain the principle. pact, yet is rugged and not capable of being Name The inventors exhibited the film on the easily put of order. Address biggest screen in the world. Some of the The ingenious product of the Electro Gas Manufacturers, is a combined elec- City State shots were of Niagara Falls. Here one Saver could see the splendid depth but strictly trical heater, with automatic injection of speaking the pictures are not stereoscopic. moist air taken from the radiator. The device connects to the car gen- Learn ... They merely give the illusion of much electrical greater depth than has ever been heretofore erator, while the gas saver is piped into the presented with any device which does not intake manifold. The advantages of moist necessitate looking at the screen through air in preventing the formation of hard ctric and tending to keep down carbon tY colored glasses or through a revòlving carbon, Ele Men Wanted You and the For World's Highest Paid Proie sslea E arnsbo shutter. The screen itself was made of deposits, have long been claimed, to s loo a which manufac- Big.pay jobs now open for electricians Ny- Week Up- finely headed glass. Appropriate music was periods of tests through inhere. We train you far tapotes Pa b> his Gua, turers of these devices have operated them most complete coure, in bean a Actual furnished by loud speakers operated 'th de)P\NPTraining Method! of electrical projects. National through the R. C. A. Photophone system. must be evidence enough to substantiate training has made thousands Leann a fascinating. easy in Iaboratories and With this method pictures have been taken these claims. of 'mums successful arkina en $250.000.00 word .. new equipment. Special Cam. of objects five miles from the camera lense, Steam and water vapor devices, which ¡h1TnNAL) i erne!1 Radio Courses. Big elecnical to trained gas mixture, go ELECTIt1CAL Q F always want National. and the full feeling of depth has been inject moisture into the awns Wrist now (m in/amwtion aba,u $a001 .,r here and engine. Apart 11 opportunities awaiting yea inculcated. improve the running of the ti tiriplti from the fact that the engine functions FREE HANDBOOK in damp weather or at night Td1soss how to be a high.paid Smashing Aviation Records more efficiently elanneal expert quickly. when the air is moist, laboratory tests show NATIONAL °=`A` (Continued front page 420) water vapor is added, ¡lI that gasoline to which .t. Barbara Sta..L sAngei ss Cal. Orchard, Maine, to Rome, Italy, was explodes with less detonating effect. forced down because of a lack of fuel The explosion is made gentler and instead To be sure of getting your copy each month, near Santander, Spain, after having made a of kicking the piston down, a more gentle subscribe to SCIENCE AND INVENTION, is applied, exercising power more Publications, Inc., non -stop flight across the Atlantic of 3.401 shove $2.50 a year. Experimenter Q. The addition of water vapor, 351 Fourth Avenue, New York City. miles. The pilots were Roger Williams uniformly.

www.americanradiohistory.com September, 1929 Science and Invention 457

thus causing this slight delay in the explosion of the gas or the more uniform application of the thrust, allows for a more advanced spark position, without the usual New Endland Mills BII*aUi "pinking." Obviously driving with the fullest advanced spark is effective in reducing the gasoline consumption. Radio Cata10 is Ready( One of the latest and most improved devices, embodying full automatic vapor air injection means to improve the operation of the engine and to reduce the quantity of fuel required to operate the car, is known as the Automatic VIX Vapor Humidifier and Gas Saver. This device is shown by illustration (E), 4 the manufacturer of which has spared no send pains to make this complete in every de- for it tail. Costly castings and other parts are NEW England Mills of- made of bronzes and other rust -resisting fers everything in ra- TODAY materials. dio at wholesale prices that The operating details of the "VIX" are spell real savings ! That's -a special trap connecting to the overflow what you will find in this for of the radiator, providing a continuous great catalog just off the RADIO supply of moist air. This trap is fitted with press, featuring Radio's v`wc a gravity shutter to keep any water which newest creations in sets, DEALERS overflows in filling the radiator from en- kits, parts and supplies. tering and interfering with the starting Everything in our catalog is SET BUILDERS of the engine. The trap is connected by backed by the guarantee of means of a flexible metal hose to the this old, stable concern and its vast resources, accumulated AGENTS injector or humidifier valve. Connecting through 17 years of faithful service to its customers. tj this valve is a piston, operating in a & SERVICE cylinder which connects to the exhaust pipe Why Our Prices are Low of the engine. The pressure of the exhaust, We are one of the largest outlets by mail to the MEN varying with the speed of the engine, is trade. Our connections with many of America's constantly changing the piston position. leading factories enables us to buy on our own This provides for automatic regulation, re- terns. Our cash resources makes it possible to lated exactly to the engine speed and con- command the very lowest prices from manufac- A.C. Electric Radios needs in turers in most cases merely a small margin sequently the carburetion. - Our new catalog contains a large selection of The "humidifier" is connected through above the actual manufacturing cost - and frequently at lower than cost. This in turn is re- the finest A. C. Electric, 6, 7, 8 and 9 tube chas- pipe and couplings into the intake manifold flected in the net wholesale prices we show in our sis and complete sets obtainable at the amaz- of the engine. catalog. We give our customers the benefit of ingly low prices we quote. Every modern radio our vast purchasing power. improvement is embodied in these marvelous The entire assembly of the "VIX" pro- electric radios. All are sold by us with the guar- vides a wholly and completely automatic antee of satisfaction backed by this 17 year old and self -regulating device, diluting the gas All Radio Dealers institution. mixture and admitting moisture according to the speed and needs of the engine, with- Save Money BATTERY SETS FOR by trading with New England Mills. This saving out any attention whatever from the driver applies to complete radio sets of every descrip- UNWIRED HOMES while running. The entire design and con- tion, dynamic and magnetic speakers, A. C. and The vast number of rural communities with struction shows that the inventor has given all other types of tubes, eliminators, batteries, homes that are not wired for electric radios offer much study and months of tests in the radio cabinets -in fact, everything required by a tremendous market for battery sets, repairs development, to make the detail parts op- dealers for resale or servicing. Every dealer and replacements. We have not overlooked this erate in unison and accomplish the gasoline knows that by buying right he is in position to important field, as evidenced by the large stock sell at prices that meet all kinds of competition, of batteries, eliminators, speakers, tubes, trans- dilution automatically. thereby increasing his profits and good -will. formers, coils, and all kinds of accessories need- The gasoline saver manufactured by the ed for battery sets. These supplies include some of the best known nationally advertised goods, Whirlwind Manufacturing Co., shown by SET BUILDERS AND such as Cunningham, Sonatron and Arcturus illustration (F), mixes air with the gas tubes, Burgess batteries, Jewel Instruments, mixture at the period of high vacuum and Belden Products, Utah, Temple, Farrand and other REPAIR MEN! popular dynamic and magnetic speakers. in addition attains a secondary mixing of A tremendous amount of business will be done the fuel, by means of a special screening this season in rebuilding sets which users want disc. This device is inserted between the to keep, and by modernizing old models. Our Send for Free Book - NOW! Radio dealers, agents, net builders, service men, etc., flanges of the intake manifold and the catalog contains everything required for this cannot afford to be without the New England Mills carburetor. The air injecting nozzle is work. Besides, we have a supply of the latest catalog. It contains everything you need for a more models of nationally renowned kits - either profitable radio business. We maintain a complete ra- automatic in operation requiring no dash knocked down or completely assembled chassis dio service department, supervised by expert radio engineers who will help you with all your radio problems. connection or manual control. ready to install in table or console cabinets, all All goods catalogued are stocked for immediate ship- at wholesale prices that permit of excellent prof- Blancke Auto Devices ment. Write for this book today. It's FREE ! Send The manufacture its to you. on your business a small and compact fuel saver, which also request stationery. connects into the intake manifold. The Catalog also contains complete Unes of electrical goods, tires, tubes, and auto supplies manufacturers of this device have on file AU hinds of sporting goods and hundreds of other items at wholesale prices many affidavits from users, which show extremely high gas mileage. 851 WASHINGTON BLVD, While there are a large number of ex- NEW ENGLAND MILLS COMPANY DEPT.] CHICAGO, ILL. cellent gasoline economizers available to owners, capable of reducing gasoline costs, it is not possible to explain all in this short article. The writer would point out, WN PLUMBERS however, that the more perfected of these Old style plumbers are fading like 3 yr. euarantae the horse and buggy. The world de- Factory to you. Save 50% on devices do materially aid in proportioning AC-8 L= ==- latest AC Electric or Bat - the fuel mixture, diluting it with air and mande modern Plumbing and Skilled r- ter Radio. Free return Trained Mechanics to do it. Unlim- $409 =-'' privilege. reducing the amount of fuel used. The ited, swift growing field. Make $50 . Big choice simpler and less expensive devices also have to $100 a week or start own shop. We of cabinets train you quick. Learn in8 -12 WEEKS the same facility to reduce the quantity of to do any Job with skilland science. Need $3229 Ligaaá AN.ILMO fuel used ; however, perfection in operation no previous experience. Strictly toolue- ing system. Opportunity knocks. hives. Radio's most amazing bargains direct from big L. most usually attained by perfection in reliable maker. Don't buy unless 30 days` tigate today -amazing offer -low tuition. old, proves entire outfit unbeatable at 2 to 3 times all details. This means more parts and World's greatest school. Write the price, for tone, selectivity, distance, volume. more mechanism, testing and designing, and - Catalog andd BIG SPECIAL OFFER UNIVERSAL PLUMBING SCHOOL m MIDWEST CORPORATION consequently a higher- priced article. 2157 Troost Ave. Kansas City. Mo. rigOgg$ MiraBScoBldg..cmannato o The purchaser of one of these fuel savers will find that it is a good investment. The savings in fuel costs are generally such that SQUAB BOOK Cp FREE the price is returned in a few months, i Breed squabs and make money. Sold by millions. through reduced consumption of fuel with Cards,_ntYQur ircolara, Advertising Own Label. Tag. Write at once for free 40 -page book beautifully "etc. Save money. Print for Others, Big Profits. printed in colors telling how to do it. Yon the additional advantages of smoother run- - Easy with printed ROCK SQUAB CO. he PLYMOUTH ^J1..ß $11. 5149. will surprised. b1\ sioß. Presss Rotary Write for catalog of prou e,. 506 H St., Melrose Highlands, Mass. ning and lessened carbon deposits. t tcti type etc. The KELSEY Co., A.47, Merlden. Conn.

www.americanradiohistory.com 458 Science and Invention September, 1929

How Would You Like to Be Another Lindbergh?

YOU, too, may win huge prizes for Men daring feats of aviation. You, These Can too, may earn the honors heaped on Help You heroes of the air by admiring With this ideal (to help the youth nations. You, too, may gain the sup- of America learn Aviation) firmly in port and friendship of the great mind, we have brought together a financial leaders of the world. But staff of men who KNOW Aviation. you've got to start, and start soon! Years of practical experience in the Only a little more than 2 years ago Aviation School of Hard Knocks nobody knew Lindbergh. Only a have taught them how to conquer little more than 2 years ago, he was the air. And now, they want to give just an obscure young man trying to this knowledge to you in AERO learn all he could about aviation. MECHANICS, the new magazine that tells all about Aviation in easy - to -read language. Within its pages We Are Looking for you will learn how a pilot controls Men Who Dare ! his airplane; how the propeller works ; what you have to do to be- Today his fame is probably greater come a flier; how to build model air- than that of any other single man. craft; how to build a glider; and At the age of 27 he stands a model of dozens of other practical, helpful the way to gain fame and fortune bits of information every aviator quickly. must know. We are looking for men who dare to conquer the air! We are looking Complete Cost Is for men who realize that the quickest route to success is in a field of Only $1 endeavor that is new and growing As a special inducement we are fast. We are looking for men who offering you the next 6 Big issues of- want to learn all about Aviation. We AERO MECHANICS all for a single want to show them how to get $1. Simply clip and mail the coupon started right! below with your dollar.

AERO MECHANICS Dept. 2509a, 381 Fourth Ave., New York, N. Y. Gentlemen: I am interested in Aviation. Please send me the next ABRO 6 issues of AERO MECHANICS, for which I enclose $1. Name Mechanics i Dept. 2509a Street and Street No. i 381 Fourth Avenue, New York, N. Y. City State

www.americanradiohistory.com September,. 1929 Science and Invention 459 What Our Readers Think (Continued from page 437) been done along this particular line? Amos Utterback, Hammond, Ind. (The unfortunate part is that science does not understand what chemical phe- nomenon takes place within us when we sleep. It is known that there are certain bodies in the nerves which become smaller as fatigue comes on, and that after sleep these bodies again enlarge. Whether or not the bodies produce the energy necessary to carry on work is something which no scientist has as yet discovered. Sleep is largely a matter of habit. Some individuals will be thoroughly rested after a sleep of but four hours. Others require as much as twelve. We do not see how a glass -enclosed bed with added oxygen and sun -rays would help to cut down the amount of sleep required. As a matter of fact, an increase of oxygen increases metabolism. Decreas- ing the amount of oxygen decreases metabolism. At the same time it adds additional losses because of the necessity of more rapid breathing.- Editor. ) ACTUAL EXPERIENCE PRACTICAL MODEL BLUEPRINTS LESSONS Correct -Easy to Follow And Enjoy New York While Learning 1 -2 Horizontal Steam En- ABOVE is pictured a corner of one ACTUAL EXPERIENCE gine details set $1.00 of our two seven -story buildings. PRACTICAL 3 -4 Boiler construction for Here, actual work is accomplished and LESSONS above set $1.00 practical experience is gained -plus THOROUGH KNOWLEDGE 5 880 Ton Bark 50c a thorough course in electrical theory, 6 -7 Twin Cylinder Steam under highly competent instructors Write today for the 48 -page booklet Engine and Boiler.set $1.00 who are themselves Electrical Experts. giving full information about the r N. Y. E. S. Course 8 -9 Gasoline Fired Loco- New York Electrical School -this is and showing pic- motive set $2.00 a school noted throughout tures of the equipment available for the world your personal 10 -11 U. S. S. Constitution, for its extensively equipped, modern use in our two seven - "Old Ironsides" set $1.00 shops, and for the high standard story buildings. IT IS ABSOLUTELY of FREE TO YOU. 12 13th Century Man -of- electrical men released each year. The War thousands who graduate 50c are eagerly The New York Electrical School 13-14 Chinese Junk ...... set 50c placed by the big electrical companies 15 -16 Electrically driven who recognize the real value of men 29 W. 17th St., New York Automobile ...... set $1.00 trained by the New York Electrical Established 1902 School. 17 -18 How to Build a Re- Mail Today flecting Telescope $1.00 19 Roman Ballista 50c The New York Electrical School 20 -21 Simple Steam Engine, 29 W. 17th Street, New York set 50c Please send me 22 "Santa Maria," complete 50c FREE your 48 -page booklet. It is understood that this puts me tinder no obligation. request i 23 -24 Model U. S. S. Ports- mouth set $1.00 Name 25 Building a Model Tug- boat 50c Address 26 Twin Cylinder Marine Engine 50c Town State I 27 -31 U. S. S. Truxton $2.00 32 Sopwith Biplane 50c 33 Speed Boat 50c 34 Airplane Engine 50c 35 LEARN CARTOONING -36 Motor Winch.... 75c At Home -In Your Spare Time 37 -38 Vertical Steam Engine $1.00 The famous Picture Chart Method REST GERS of teaching original drawing has 39 Cannon 50c opened the door of success for hun- Men, get Forest Ranger job; $125- dreds of beginners. Whether you 40 Steam Roller.. 50e think you have talent or not, send 41 $200 month and home furnished; hunt, for sample chart to test your abil- Prairie Schooner... 50e ity, and examples of the work of Lincoln fish, trap, etc. For further details, write students earning from $50 to $300 Sport Mono- per week. Please stale your plane (man- carrying) $6.75 NORTON INST. DENVER, COLORADO THE LAN DONSCHOOL Gerber Monoplane 1460 National Bldg., Cleveland, O. (man- carrying) $1.00

Send Orders to Wind Can Blow I'LL PAY YOU We quickly It BLUEPRINT DEPARTMENT teach you by mail, or Out at school, in pare time. agdemand. Bigfuture. Interest- $20 A DAY SCIENCE AND INVENTION ing work. Oldest, foremost school. To 'EARN $50 TO $200 WEEKLY Show My Mystery Lighter to Otto Md.,home -study graduate, Men. What Makes It Light? All 381 Fourth Avenue made $12,000 from hie business in ono year. Jan Vaseue N. Y., gate $25 fora show card. Guaranteed. Sample With Sales New York City Crawford, B. b., writes: Earned $200 while talc- If STARTING Plan 25c. Sample Gold or. Silver Plated, course." Writs for complete information. $1.00. Agents write for proposition. DETROIT SCHOOL OF LETTERING NEW METHOD 179 Stimson Ave. Eat. 1899 DETROIT. MICH. 11! MFG. CO. IIIInI l Desk S.I. -9 Bradford, Pa.

www.americanradiohistory.com J 460 Science and Invention September, 1929 This Man Made Slater Refuses Spirit Test Constructing a Heliograph. $51700 (Continued front page 399) By L. B. Robbins Stone, E. de Lopatecki and Dave Lustig (Continued front page 433) were also present. Songs and serinons occu- exactly opposite the pivot bolt. Bend in 3 Weeks! Then amid pied the first part of the program. slightly so they are 5 inches apart and OVER $170.00 weekly much applause, John Slater mounted the stand them exactly vertical as shown. profit is averaged by raised dais and proceeded to read messages W.V. Jones. W.D. Fauley, Select mirror D with care. The surface in sealed envelopes. He repeatedly im- should be free from waviness. It should W.Va., earned $257.00 in his audience the fact that he 21 days. Shedrick, of Ohio, pressed upon be about 5 inches in diameter. Turn the cleaned up $177 in 4 days. had no way of telling the contents of the mirror over and strike the exact center These are typical examples sealed envelopes ; that he did not know the with dividers. Scribe a / circle from w. v. JONES, Texas of earnings with this most people for whom he read these messages, this point, scraping away the backing with- amazing, gorgeous and beautiful line of electric that they never saw him, nor he them, and in this circle. Drill a small hole in the signs. No experience is needed to take orders for that there was no other possible way in metal edging of the mirror in line with Dazzler and Rainbow Glow which he could have gotten the information. the center. Then at the exact top drill To forcibly impress upon his hearers the two small holes in the glass for the ELECTRIC SIGNS magnitude of this mysterious power that trunnion X which is secured by two small Gorgeous, colorful signs with Rainbow Glow Slater claimed to possess, he stated that he bolts. Trunnions are made by bending a flasher. Sizes and styles to suit any kind of store, had a standing offer of $5,000 that he piece of stiff brass U- shaped as detailed. garage, theatre, etc. Cash or time sales. Commis- would give to any one who would prove holes in sides are for the pivoting bolt sion of $12.50 to $50 per order. The Unlimited field. that he tampered with or in any way ex- as shown. You Can Easily Earn amined the contents of any of the sealed Mount the mirror between uprights CC envelopes. This was the occasion for by drilling a hole in the top of each $100.00 a Week! action. Dunninger jumped up and asked, threaded for small machine screws to fit Only a few orders a week puts "May I say a few words, please ?" He in pivot holes in sides of mirror. When you in the $5,000 class. We work was promptly booed down, told he would properly assembled the bottom of mirror with our men -give them detailed get a chance later, and advised to resume should swing 2 inches clear of A and the instructions -show them in an his seat. A strong arm squad found its diameter line across mirror should be ex- easy, understandable manner how way to that part of the hall where the actly parallel with surface of A. to figure and and help quote prices Science and Invention Magazine committee is metal rod them sell through our intensive co- The mirror arm E a small operation. Commissions on sales were seated. sliding inside a tube which is adjusted by are paid promptly. This is a digni- Knowing that Slater absolutely refuses to a thumb screw. Drill several closely placed fied proposition -a permanent connec- answer any more questions after his séance holes in the top of the rod and pivot to the tion and the money earning possibilities- are unlimited. period is over, and knowing that he un- trunnions with a cotter pin. Flatten the Dazzlers Are the Lowest Price High doubtedly would evade a test, Dunninger bottom of the tube and drill a hole through Grade Electric Signs on the Market. let slide to the ; Sold to was reluctant to the matter the center attach to key as at F. Merchants on Easy Terms. he to Leuy sleln nf- end of the séance as was requested The key consists of a wood bar 5 inches Write atueuBo k do. At quarter of 11, Slater had about 1 high and inch thick. Cut Signs and long. inch / TodayElectricY full details of big money- 10 more minutes to go. He had just com- one end down half the thickness and fit making proposition. Some exclusive no know- territory still available. Write or wire pleted saying, "And I had way of with a poker chip to act as a knob. Drill at once for complete information! ing the contents of your letter, did I ?" and pivot the other end as indicated inside CHICAGO SIGN SALES COMPANY While he was being roundly applauded, Mr. an inverted U- shaped metal piece Y fas- Dept. es Charlotte, North Carolina Kraus jumped up and waving the sealed tened to base A and straddling the center message in his hand, exclaimed in a voice line. The washer should rest over the that could be heard above the handclapping, end of A. A second piece of metal forms FREE FALL "Mr. Slater, will you read the contents of an adjustment bridge over the middle of this envelope for $21,000? We have the the key. This bridge Z is fitted with an check on hand made payable to you." adjustment screw that can be turned down CATALOG Dunninger added, "Will you do this, Mr. from the top. A flat spring fastened to Just off the press Slater ?" A under the key near Y holds the key Showing Hunting Slater's response was, "If this man had solidly against screw Z. Drill several Shoes, Duck Hunt- adopted these tactics in a Roman Catholic holes through the key just back of Z and ing Boots, Leather Caps, Innersoles, Church, or a Jewish Synagogue, what cut into a slot. Then drill a hole through Sleeping Bags, etc. would you have said? Throw him out !" sideways and, letting the flattened end of L. L. BEAN, Mfr. With that, the strong arm squad started to mirror arm E down into the slot, secure 424 Main St. descend from all directions and to carry it so it pivots easily with a small bolt. Freeport Maine out Slater's order. Again Dunninger re- Two tangent screws GG must be fixed peated, "Will you do this ?" Slater re- near B at each side, near the back and fused, but his refusal could not be heard work in tapped metal uprights fastened THE him of PO NTEDPEÑ above the din of "Put out! Throw to B as shown. These adjust relation N KOGRAPH !" The Managing Editor tarried on B. A white painted wooden dowel 10 DAY FREETRIAL \- { tref him out A smoothly, from coming up in the small end of A, answeringan hink pe. and prevented the squad standing vertical and pencil. Never blots ISANESlZE AS ; he trans- scratches, ieaksordries \ in back. Slater heard the challenge with thumbscrew, completes the Makes 3 carbon \ ST ANDS875 refused it! mitter. copies at one time FOUNTAIN withoriginalinink PENS The editors of SCIENCE AND INVENTION Set the sub -base B on a camera tripod .J MONEY.Paypostman$1.50 plus postage. Sent prepaid if cash is uere asking Slater to do nothing more than or other firm support. A short tripod aco o Elar a' twi h order. Moneyback if netut- he a can on the isfied,within 10 professed to be able to do. In Cath- or box so the operator sit w,atr'n,crw days. to Ea .INKnoRapH COMPANY, INC. olic Church, in a Jewish Synagogue, or in ground makes for a steady beam. Sight 199 -563 Centre St.. New York [ Send for Inkdgrapn or write for Sales pian booklet. any other religious assemblage, of this na- along the key so adjusting nut on Z and ktki Bite value. - cella on sight - no investment. ture, any member of the congregation has vane come in line with the point to which a right to question the minister and expect you wish to transmit. Then with the the courtesy of a reply. It seems that in mirror at angle shown while key is held 30 DAYS ,yra spiritualism one entertains no such right. down, adjust the tangent screws so the TRYFREE RADIO One cannot expect the preacher or the vane turns in its horizontal plane and the The Ranger Radio is a resu t of 7 years development. It i to-day fast becoming the moat favorably- known radio -now leading he minister to do the very things he claims sun's rays are played upon the receiving field its predecessor, the Ranger Bicycle, has for 80 years. The Screen-t;ri0 Tube Ranger Neutrodyne (with 9 tubes) is made he is able to do. spot. Make final adjustment with mirror under patents of R. C. A. Ranger assures you of selective reception from near and distant stations. You may now own one of It seems that in spiritualism the mediums sliding rod and lock in position while key hese distinctive Rangers with Dynamic Speaker in DeLuxe Console by paying as low as $10.00 down and balance in 10a months. are not supposed to accept $21,000 for a is down. When ready send the code ex- Table models as low as $40.00. Rangers come all ready to use- simply insert tubes and plug into your electric light socket -no test séance, even though they could turn actly as with a radio or telegraph key. trouble than to connect an electric floor lamp. The name MEAD has been known for Ranger Precision Products for 30 Yearn. that money over to charity or to the fur- The length of time the key is down deter- Write today for Catalog, Prices and Terms and marvelous new is or a dot. introduc- Mead Cycle Co., Dept. ,X -i7s, Chicago therance of their cause; that evidently mines a dash tory offer. unethical. By throwing the beam of a powerful And so we conclude with the statement searchlight on the mirrors at night mes- that if this man who is advertised as being sages can be sent after nightfall. BIG MONEY The sighting is checked up by having Newest and Easiest Gold Sign Letters the world- renowned medium, John Slater, in the market. MAKE 95.00 to $10.00 and who since the age of 22 has been the unsilvered spot in the center of the an HOUR. You don't have to be a on sign painter to make signs with our producing similar effects, is not capable of mirror cast a shadow the white -painted NU -WAY QUICK SLIDE -OFF WIN- giving just one for the benefit of not only vane in front of the mirror. This should DOW LETTERS. Instantly applied without varnish. Guaranteed to outwear any hand - his audience, but also science, can we not appear there at any angle of the mirror painted sign. Write quick for FREE SAMPLES. flash is correctly on the Street. consider all mediumistic manifestations as when the centered RALCO SUPPLY CO., Dent. 90. Boston. belonging to the same category? receiving point.

www.americanradiohistory.com September, 1929 Science and Invention -461 Animals that Learned to Fly Cet two wonderful You get then Cen By Dr. Ernest Bade books by mailing aine High Quality, coupon below. Imported Drawing (Continued from page 407) Instrumenta, I4 Other Tools and a Drafting Table - all included in pumped full of air and the lungs filled to my Home capacity. In this position of gliding the These Two Training flying frog always lands upon some solid Course. object. These creatures are only active Books - at dusk at which time they seek their food. Mail Coupon! During the day they cling to the leaves, the green coloring of their body blending Yes, Absolutely with the foliage, the gayly colored parts being hidden between the stomach and the folds in the joints. FR E' Money-Back Flying Fish Agreement ITHOUT question the so- called fly- I train you at home under ing fish are mere gliders although a positive Money - Back they do throw themselves Agreement. If my training comparatively does not satisfy you after high into the air. This is not the case with any other gliders, you have finished, you get as they are not built for 2 every penny back. an upward flight, and are not provided with a driving muscular device attached Books Age both to the skeleton and to the organ of or Lack flight, as is the case with bats, birds and of Education, insects. Here it is nothing more than an FREE No Drawback adaption for enlarged bodily surface area Just Send the Coupon Below! which increases the resistance Previous experience is of the air not necessary. to their falling and so enables You do not the creature Jobs for Draftsmen need to be a college man to glide downward gradually. The flying or high school graduate. fish prolong their flight over the water in Great Industries -Learn At Home - who are Automobiles-Electricity-Motor Busses making from $3,600.00 to $9,000.00 their fall -but they can not fly. -Aviation -Building Construction. year. There is a big future for draftsmen be' cause you plan and supervise the work of Help As Long There are jobs for Draftsmen in all of these you go into business for yourself. industries and in hundreds of others. Get started now toward a better position, pay- AsYou Need It is expanding to enormous ing a good straight salary, the year around. Aviation proportions. Comfortable surrounding.. Inside work. Electricity is getting bigger every day. As my student you can Motor Bus building L becoming s leading Earn As You Learn write to me any time you world Industry. I tell you how to start earning extra money a few weeks after beginning my training. want to and as often as you Building of stores, homes, fsctoites and office buildings Is going on all the time. Employment Service like and I will give you No structure can be erected 'without plans After training you I help you to get s job with- help on any subject per- drawn by a draftsman. No machinery can be this built without plans drawn by a draftsman. ployers of Dyraftsmment ome to me for men taining to draftsmanship. I train you at home, in Drafting. Keep the because they know that Dobe Trained Men I will advise you about job you have ow white learning drafting. make good so they have learned drafting by actually doing the work themselves, io n jobs, extra work, fees and will traineyou in drafting right where you practical way. Employers not are in your spare time. I bane trained men taking chances an men trained by me. how to make extra money. If You Earn Less Than $70.00 a Week FREE BOOK COUPON Schematic diagram of the wing of a bird. Ask for My 2 FREE ENGINEER DORE Books 1951 Lawrence Ave., Div. 1 -4, thumb feathers; 2 -10, 14 -26 Chicago hand or primary Send me free of all cost your book, "Successful Draftaman- feathers; 3 -17, forearm feathers; 4, shoul- hip". also plan to earn money while learning and pr f of Man this coupon. at once. Get "My Pay Raising big mng paying positions. Also your new book. "MrPay - der feathers. Plan" and "Sueeeesful Draftsmanship ". Both of Raiei Plono an. them point the way to Success. You owe it to yourself to find out what a big opportunity there is in practically all for Draftsmen. These two hooks are Free. They come to you postpaid. Noma______-.______s_ _ Mail the Coupon for them TODAY. Very few of all the so called flying fish ENGINEER DOBE Rddrses_.. are true gliders. The majority hurl them- 1951 Lawrence Ave., Div.14 -26 Chicago selves out of the water and then employ re,t ohtea their comparatively large and well developed pectoral fins as gliding surfaces. In this way the butterfly fish, Pantodon buchhol.^i, an African fresh water fish, jumps out of the water after those insects flying just above the surface. The large pectoral fins are spread and these carry Win a Nash Sedai the fish for a short distance before it Clip falls hack into the water. In the same way This Or $2,750.00 in Casn Someone who answers this ad will receive, absolutely free, a the Indian fish Muria danrica glides when Ad fully equipped 7- Passenger, Advanced Six Nash Sedan, or its the pectoral fins are full value in cash ($2,000.00). We are also giving away a spread. The same is Dodge Sedan, a Brunswick Phonograph and many other val- also true of the South American species uable prizes-besides Iundreds of Dollars in Cash. This offer Gasteropelecus stellatus and the related is open to anyone living in the II. S. A. outside of Chicago. form Canegiella fasciata. When their life is endangered they cut through the Solve this Puzzle There are 7 cars in the circle. By drawing 3 straight lines surface of the water. Breast and tail are you can put each one in a space by itself. It may mean usually left in the water but the pectoral winning a. prize if you send me your answer right away. fins heat the surface, and sometimes they rise into the air and glide 2 $750c00 Extra for Promptness for or 3 yards. In addition to the many valuable prizes and Hundreds of Dollars in Cash. we are also giving a Special Prize of The organs of flight, or better, gliding, $750.00 in Cash for Promptness. First prize winner will re- are far more perfect and ceive 52,750.00 in cash. or the Nash Sedan and $750.00 in more highly de- cash. In case of ties duplicate prizes will be awarded each veloped in the salt -water fish. Two species Send one tying. Solve the puzzle right away and send use your i answer together your name are of - special importance; the flying fish Answer with and address plainly written. E rocoetus and the flying Today $4,500.00 in prizes- EVERYBODY REWARDED. gurnard Dacty- John T. Adams. Mgr., Dept. 3796,323 S. Peoria St., Chicago. ID. lopterns. The large pectoral fins of these animals when extended horizontally, produce a very good gliding surface and in the flying fish the peculiarly formed, tail fins also aid in its flight. The tail fins of To be sure of getting your copy each month, subscribe to Science and Invention -$2.50 a year. all fishes act like propellers in driving or Experimenter Publications. Inc., 381 Fourth Avenue, N. Y. C. "sculling" the creature through the water,

www.americanradiohistory.com 1929 462 Science and Invention September,

and in Exococtus, the flying fish, the lower body is bent into a quadrant and the large flap of the tail fin is much longer, broader tail fin becomes the rudder and the air re- and stronger than the upper flap. sistance turns the direction of flight. Under normal conditions the course of When this fish swims through the water, flight lies just above the surface of the the large pectoral fins. are folded closely to water but when caught in rising currents the body and, by means of a sculling move- they may be lifted as much as 18 or 20 ment of the tail fin, the fish is driven for- feet. Like large blue darning needles ward rapidly until the force is increased schools of these creatures, frightened by sufficiently to hurl it above the 'surface a steamer, skim over the water, sink into, of the water. Then the pectoral fins are spread and the creature glides through the air. As its speed decreases, the heavier tail sinks back into the water. A few re- newed vigorous driving blows with the tail fin, suffices to lift the animal into the air again and permit it to continue its glide. The fish, therefore, can not remain continually out of its natural medium. Since the tail fin can not act upon the air, it must be used in the more resistant water to be effective. Flying fish represent an incomplete air- All 3 for5fj plane and the lower, somewhat lengthened tail fin may be considered as acting like a propeller when the fin is partially su'o- Complete New Novels merged. Then, too, the flying fish take advantage of rising air currents produced by 3PFamous Authors at the crests of the waves. They cover considerable distances in the air, and flights of approximately 600 feet have been ob- Real he -man stories, these ! New served. Seitz noticed the flight of these Stories of the West of Old-when animals from the bottom of a boat and guns flamed and the covered wagon said that the jump from the water was was a familiar sight. Now a half - aided by a lively fluttering movement. 8 inches in length beat their 3 novels in mag- Specimens dollar brings you all pectoral fins from 4 to 4/ inches when azine form (shown above). Each they reached the crest of their flight. Then written by a famous author of West- the gliding membrane is stretched hori- ern Tales -J. Samuel Sisco, Charles zontally or slightly upward and the fish Alden Seltzer, and Charles Wesley glides gently downward without any con- scious movement. A fluttering of the pec- Figures 1 to 5 show the fingers of the bat. Sanders. toral fins is noticeable when the fish rises the second time. Then, too, the same Men Who Made History! flutter is observed when it glides over the the valleys of the waves, carried upward crest of a wave, but this probably only again by the rising currents of the follow- i\Ieet young Benson, that fighting occurs when the wind lies in a certain di- ing crest, and disappear in a graceful glide, fool who enjoyed bucking odds with rection from the axis of flight. back into the water. with his gun. Hit the trails of gold The muscles of the pectoral fins are And so, watching and studying, during Dutch Schultz, happy -go -lucky ad- strongly developed to produce both a lift- centuries of restless activity, the brain of venturer of the mining camps. Meet ing and a forward driving force. In birds man has attempted to solve the problem Parson Bill, that strange combination the muscles comprise about 1 /6th of the of building a flying machine which would and fighter, who could entire bodily weight, in flying fish it is carry him at will into the dizzy heights of of preacher 1/32d, in non -flying relatives it is only the air just as a boat is carried upon the handle a gun with the best of them. 1 /154th, while the bats stand between the ocean. It was in our age that the problem Meet them all -reckless, fighting, ro- birds and the flying fish with a muscular was successfully solved by building a light mantic adventurers. They wait to give weight of 1 /13th of their entire weight. motor to drive a propeller. you many an hour's reading joy with- When the flying fins are spread they in the pages of these 3 great novels. seem to be slightly curved, the curvature being 1 /10th the height of the chord or the These Same Novels Would Ordinarily Cost You $6.00 Crack Ups if you bought them in the bookstores. By printing in magazine cover style By Joseph H. Kraus 11 cost we save you times what they (Continued from page 404) you. Imagine paying only 50c for 3 complete V novels. tries to execute a more spectacular scene than his last and he tries to come being killed as possible without Send for them by enclosing as close to Mail This 50e with the coupon below, actually arriving at this destination. and we will forward Coupon Today all 3 vowels by e- flier himself rarely gets any pub- At 1 we see the muscle of a flying fish. At The turn mail. Do it now, while they last. licity, although once in a while, if he en- 2 is perceived the muscle of a relative of a Man ism se sal gages in a particularly severe crash and - -__1 flying fish. is quite badly mangled, his name appears NOVEL MAGAZINE CORPORATION as a filler in the local newspapers. He 381 Ave. , New York, N. Y. Dept. 2509Z, Fourth of the fins. They also possess, if may eventually occupy a little more space width columns, but such pub- Gentlemen: only to a moderate degree, a strengthen- in the obituary Please send me the 3 complete novels shown licity will never do him any good. above. I enclose 50e (in stamps or coin) to Day ing of the front of their gliding surface for them. as well as a certain curvature which aids Yet it's all in the game, plenty of fun, the forward movement just as it is the exercise, a real good thrill, and the avi- case with both bats and birds. ator can see himself doing the trick as Name don't we duration of flight lasts longer. if often as he desires. After all, The all take as great a chance daily? Street the fish is flying into the wind, than if it glides with or at an angle to the wind. The photographs on these pages indi- While in flight, the fish is capable of cate that, if you know how, you can fall City State steering a course diagonal to the course with a plane and land as safely as if you L -- -- selected at the beginning of the flight. The, fell off a motorcycle or horse. www.americanradiohistory.com September, 1929 Science and Invention 463 You Can Call Your Home From Moving Train TRAVEL (Continued from page 438) FOR telegraph engineers in their experiments, and it was on this car that much of the preliminary work was carried out. Many problems had to be "UNCLE solved and a special modulator circuit developed. Difficulty was experienced in the design of a suitable antenna system, the proper carrier frequencies SAM" and the establishment of a reliable duplex transmission. Circuits and Apparatus

ARADIO telephone transmitting and receiving set are placed on the train and similar apparatus positioned near the railway right of way constitutes what is RAILWAY POSTAL CLERKS known as the terminal station. It was found necessary to employ a separate antenna for transmitter and receiver. The Commence $1900 Year telegraph lines paralleling the railway Many other U. tracks are used for this purpose at the S. Government Jobs open to Men and Boys 18 up terminal station. Filters are interposed POSTOFFICE CLERKS CITY MAIL CARRIERS between the terminal receiver and trans- RURAL CARRIERS GENERAL CLERKS mitter and the telegraph lines so that there PROHIBITION AGENTS - - is no - -- interference between the new system These are steady positions. U. S. Government employees get their pay for full twelve FRANKLIN and the existing telephone and telegraph months every year. INSTITUTE systems already operating over these RAILWAY POSTAL CLERKS Dept. A -177 ROCHESTER, wires. The Railway Postal Clerks now commence at $$1900 train antenna consists of two a year, being paid the first / N. Y. pairs of parallel wires strung along and fifteenth of each month. $79.16 each pay day. Their pay is quickly in / the creased, the maximum being $2700 a year. $112.50 each pay day. They get roof of one of the cars. The antennas extra allowance for hotel expenses when away from home. / Rush to me without charge (1) a full de- used in the German system are wires ex- PAID VACATIONS .' scription of the sr, position tending along the roofs of several Railway Postal Clerks, checked below; (2) Free cars, and all Government employees, get a yearly vaca- /.3) cony of 32 -page illustrated tion of 15 working days (about 18 book, thereby necessitating the employment of days). On runs they usually work 3 ,e..,1/4) "How to Get a U. S. (lays and have 3 days off Government Job "; (3) coupling devices to allow the cars to duty, or in the same proportion. During this Tell me be off duty and vacation, their pay continues just as how to get the position checked. separated. The radiophone working. though they were o messages are When they grow old, they are retired with a pension. ... Railway Postal Clerk ($1900- transferred from the train antenna to the CITY MAIL $2700) CARRIERS -POST OFFICE CLERKS O Post Office Clerk ($1700- $2300) Clerks and nearby telegraph and telephone lines, are Carriers get $1700 the first year regular and automatically in- ..City creasecre Mail Carrier.... ($1700-$2100) $100$ a yyear to $.100 with further increase to $2300. They also have ti conducted along these wires and received 15 days' vacation. Examinations Rural are frequently held. City residence is Mail Carrier ($2100- $3300) at the terminal station. unnecessary. ..Bookkeeper GENERAL CLERKS ($144041920) General Clerk (Open to men or women 13 or over) / ($1260 -$2100) Salary to Prohibition Agent Frequency of Signals $1200 $2100 a year. Pleasant clerical work in the various / " ($230042800) departments and offices at Washington, D. C., and throughout the country. The 1030 Census will mean hundreds of appointments. Name CONSIDERABLE research Get Free List of Positions work was / Andress PILL OUT THE COUPON. Tear it off and mail it TODAY entailed in the determination of the -NUW' / Use this coupon before you mislay it- correct carrier frequency, since the at- / WRITE OR PRINT PLAINLY tenuation of high frequency currents on wires is opposite to that experienced when these currents travel through the ether. Compromise frequencies had to be chosen, so that the minimum of over -all attenua- tion would be experienced. Experiment showed that frequencies between 90 and 200 kilocycles (3,500 and 1,500 meters) were the best suited for this purpose. A different frequency is used for the carrier from the train to the terminal station than that for the carrier from the terminal station to the train. The power of each transmitter was set at 20 watts, as this is sufficient to bridge the maximum distance of transmission that separates the trains and the telegraph wires. At places KLAXON where the lines are more than 200 feet HORN Here you are boys and girls! It's just what you from the train auxiliary pole lines are GOOD BRAKES have been waiting for. The RED BUG erected. PLENTY OF V7' j42.7-, RACER -a real auto for young folks. SPEED 4 % A real classy, electric roadster that Phone Lines "Tied -in" ¡, ;t ., has plenty of speed and will do almost t li anything a big car can. Strongly _ -í4O` built FOR connecting the terminal ` horn-electric lights, station lßlíI* 1 good brakes.Nothing with the ordinary telephones a circuit 1, `-IJ' / -K ge known as out of order. Drive dad to the conjugate Wheatstone bridge ^t' work, < runmother's errands circuit is used and enables the two pairs i.!i/G and betheidol of your town of wires from the receiver jír and transmitter with a RED BUG RACER. to be connected to a single pair of wires Ill!!!"- / constituting a telephone line without having // ////// FREE TO BOYS AND GIRLS the transmitter and receiver interfere /. I with each other. am going to give away a limited number of RED The voice currents are BUG RACERS to boys and girls allowed to pass from the receiver whowrite me quick.You to the "r0 may get one absolutely free and FREIGHT PAID to your telephone line and from the telephone line home. I do not to the transmitter. want one cent of your money-just a little of your spare time before or after school. Be first in your neighborhood to The design of the signal /`\geta / RED BUG.Write circuits permits TODAY -QUICK. Justsay, "I want a Red Bug Racer." the transmitting amplifiers and power os- cillators to be turned off when the line is RED BUG BOY, BOX 3799, BATAVIA, ILL.

www.americanradiohistory.com 1929 rt6a- Science and Invention September,

not in use, and yet it is possible for either a boiling point of -6° C. This gas is col- operator to signal the distant station by lected by passing it into a dilute solution ... A New IDEAL simply turning a key. This transmits sig- of hydrochloric acid where a soluble salt nals to the station, which ring a telephone of the compound is formed. Then, by of Model Airplane bell. In order to eliminate the possibility the addition of an aqueous solution of false signals, the circuit is so arranged sodium nitrite, methyl alcohol will be ob- that only a specific combination of im- tained. Thus the op- Methyl amine is prepared with the aid pulses will ring the bell. the erators need not be connected with each of acetamide, the final product being salt, methyl amine hydrochloride. Place other continually. flask. A traveler on the train wishing to com- 10 grams of acetamide in a large home or make a busi- Add 9 c.c. of bromine and shake lightly. municate with his cold ness call asks the train operator to ring a Then add a previously prepared and The certain number. The operator signals the solution of 12 grams of potassium hy- him nec- droxide in 50 c.c. of water. Pour the terminal operator and gives the solution "American Eagle" essary information. When the connection alkali slowly into the bromine Wing Span 26 h,. Weight: 3 ox. has changed to a bright is the notifies the pas- until the red color Distinctive in design . new In construc- made train operator flask a light, durable, fast -flying model yellow. During the mixing the tion.... senger and he will then be able to con- is with IDEAL'S twenty years' experience be- called. should be kept cool. If a precipitate hind it, and months of dependable per - verse with the individual few drops of water to dis- formance before it! Wonderful stability in The first installation of the equipment formed, add a This is the first reaction, and a the air, and GUARANTEED to FLY when will be between Montreal and solve it. hand or ground launched. Many new con- probably mono -brom derivative of acetamide is struction features; motor can be wound Toronto. A number of the important with winder without removing from fuse- formed. This is now placed in a dropping lage; landing gear; new type trains between these two cities will be so is placed in a flask indestructible months. funnel and the funnel propeller. Construction is easy. fitted within the next two or three containing a solution of 30 grams of po- Construction Assembled tassium hydroxide in 80 c.c. of water. A thermometer reaches to the solution. Set $2.50 Model $5.00 of Sold by Toy. Sporting Goods and Depart- Then gently heat until a temperature ment Stores. Ask for the IDEAL "Amer- Experiments with Little - 70° C. has been attained. Then slowly ican Eagle" Model. If unobtainable, order reaction mixture from the f unnel direct. West of Denver, prices are 50c drop the higher. Known Chemicals into the hydroxide solution, taking care 64 -Page Catalog of Models, not to heat it above 75° C. If the tem- Parts and Supplies for Builders 5C By Dr. Ernest Bade perature rises above this, cool the flask Keep this temperature & SUPPLY CO., Inc. (Continued front page 426) with water. at IDEAL AEROPLANE mixture is colorless. 22 -24 West 19th St., New York City until the reaction being used, its explanation is of value. This may take from ten to fifteen min- First iodine is added to wood alcohol utes. Then add a few pieces of broken to forni methyl iodide. This process is glass or pumice stone to prevent bumping similar to the preparation of ethyl iodide, and heat gently to drive off the gas methyl Complete, practical home-study but greater care is necessary in its pro - amine which is collected in a mixture of courses prepared by some of the it boils at 43° C., just a and 20 c.c. of hydro- fr best -known chemists in this duction, since 20 c.c. of water country, including little more than half the temperature re- chloric acid in a beaker. The gas is led ALLEN ROGERS, B.S., quired to boil ethyl iodide. The methyl to the beaker by means of a funnel in- M.S., Ph.D. -Head of Department of In- iodide is then caused to react with potas- verted in the acid and which dips just dustrial Chemistry, sium cyanide in an aqueous wood alcohol below the acid level. This prevents the Pratt Institute; L. solution, whereby methyl cyanide (ace - acid from being drawn up into the dis- M. TOLMAN, Ph.D., Vice -president, tonitrile) is obtained. At the same time tilling flask. As soon as the liquid in the United Chemical potassium iodide is formed. Methyl cya- condenser shows no alkaline reaction, the and Organic Prod- nide is a colorless liquid, soluble in all is discontinued. ucts CO.; BRADLEY distillation it boils at 82° C. hydrochloride is ob- STOUGHTON, B.S. - proportions in water and The methyl amine Head of the e- The methyl cyanide is then reduced with tained by evaporating the solution in the partment of Metallurgy Lehigh University, and methyl cyanide being bath. When the OwEN L. SHINE, Ph.D.-Professor of Applied metallic sodium, the receiver over a water Chemistry, University of Pennsylvania. dissolved in wood alcohol. Four mole- salt is dry, place in a beaker after pow- Mail Coupon for Free Booklet cules of hydrogen, which are liberated dering and add 15 c.c. of hot absolute al- alcohol, enter the methyl cya- cohol. This dissolves the methyl amine INTERNATIONAL SCHOOL OF CHEMISTRJ from the Division of the nide and convert it to ethyl amine, a very hydrochloride and, on filtering, the am- .Intonational Correspondence Schools. at 19° C. It is also present will remain on Box 6196 -F, Scranton, Penna. volatile liquid boiling monium chloride I amine is methyl amine Without cost or obligation, please semi me full I soluble in water. This ethyl the filter. Recrystallize the details of your home -study course in readily converted to ethyl alcohol by dis- hydrochloride and dry in a dessicator. I Analytical Chemistry Metallurgical Chemistry I amine in dilute hydro- may also be spread upon an Chemical Engineering D Short Chemistry Course solving the ethyl The crystals I Industrial Chemistry Pharmacy chloric acid and then adding an aqueous unfolded filter paper and placed in a pint warming, chloride. The Name I solution of sodium nitrite. On jar containing calcium must fit tightly. I bubbles of nitrogen are evolved and ethyl cover of the jar Address I alcohol will be found in solution. As a whole both types of reactions are This process adds a carbon atom. It complicated but well within the range of c. is a building -up process, which, as time advanced laboratory work. The breaking goes on, will become more and more im- down and building up of a series will al- portant in the chemical industry. The ways remain vital factors in chemical SI MAIM ME(1113 those on a commercial scale Excellent results obtained with tearing down or splitting up of a complex work, the procedure short wave receivers. y batteries on -De- compound into one or more of a simpler probably taking short cuts, using entirely 100-Volt Edison Element. Non im- ich Rechargeable ` B" nature is also a process extensively different reactions and, which is more Shipped dry,Ra with with charger. charger, employed. Here, for instance, a higher portant, entirely different raw products solution, $12. 140 -Volt with Power Linit, with is which the desired end products may $17. 180 -Volt no member of a homologous series con- from Prickle Charger, $24 Send member. That be more easily and more cheaply obtained. Money-peg verted into the next lower Write for our Free Literature means that ethyl alcohol may be converted But the values, for the laboratory, of to Ill to methyl alcohol, just the reverse of the changing from one member of a series previous process. the next will always be great, for often a Here the ethyl alcohol is oxidized by member, difficult to obtain in the open sulphuric acid and potassium bichromate market, will then be within the range of to, first, acetaldehyde, which is not dis- production in the laboratory of a compe- tilled off, but, on heating with a reflux tent chemist. ORRECT condenser, it is further oxidized to acetic Your acid. The dilute acetic acid obtained is NOSE concentrated by making a sodium salt of Improve your appearance with the the acetic acid, and on distilling this salt ANITA Nose Adjuster. Shapes flesh is In the Next Issue- and cartilage-quickly, safely and with sulphuric acid, pure acetic acid painlessly, while you sleep. Results obtained. This acetic acid, which may are lasting. Doctors praise it. 68,000 be in the vinegar fermenta- article on users. Write for 30 -Day Trial Offer also obtained Another valuable and FREE BOOKLET. tion of ethyl alcohol in dilute solution Finance- ANITA INSTITUTE, K -73, Anita Bldg., Newark, N. 1. with more ethyl alcohol, forms ethyl acetate with the aid of sulphuric acid. The To be sure of getting your copy each month, is changed to acetamide M. Caddell Invention, $2.50 a year. ethyl acetate then By Alfred subscribe to Science and acetamide to methyl amine, which EXPERIMENTER PUBLICATIONS, Inc., and the 381 Fourth Avenue, New York City. is a gas at ordinary temperatures having

www.americanradiohistory.com September, 1929 Science and Invention 465

Is a College Education Worth While ? NOW- America's Great Electrical School (Continued from page 454) i and of any other subject. In every field TrainsYou For SUCCESS in there are great scholars who never went to college. The question is, however, can that grasp be as easily acquired, or when acquired will it be as comprehensive, when tLECTRICITY 'PIIAA in ÑtlórG1.N11taNG acquired by serving an apprenticeship in 1611 practical work as when acquired as a result Your AI rv:ó,av,o ? In of specialized and systematic study Own Home ,;,,U law, medicine and engineering, there does IA' not seem to be much doubt as to the advan- school. There is a growing rec- Same course, same methods, same tage of the faculty of skilled engineers that ognition of the advantage of the school have made the School of Engineering business. internationally famous now trains you method of training for in Practical Electricity right In your Of course the school does not entirely own home. Here is your golden opportunity to get out of the rut of un- displace the apprenticeship. The graduate skilled, low -paid labor and, through of the medical school serves as an intern, supervised home training, enter the law school serves fascinating field of Electricity. and the graduate of the BIG PAY for ELECTRICALLY TRAINED MEN as assistant in a law office, to learn the QUARTER OF A CENTURY OLD $3,000 TO $10,000 A YEAR! practical sides of their professions under Electricity is the "heart" of modern industry. Big man- veteran experts. General principles are OVER 25,000 GRADUATES ufacturers are pleading for men trained in Practical For over 25 years the School of Engineer- Electricity. Salaries of $3,000 to $10,000 a year now ing has learned in the schools, practical details are pioneered the way in Practical Elec- are common. Prepare yourself for this field NOW ! trical Training. Over 25,000 graduates learned under experts in a hospital or in from every state and most foreign countries. an office. No college education, not even Not a mere correspondence school but a GREAT fully established college specializing- in Elec- OPPORTUNITIES IN THIS GROWING FIELD a course in a business school, will fit one tricity. Recognized by U. S. Government. Electricity is forging ahead with mighty strides. Important deveI- has a long Endorsed by leaders in industry. Graduates opments in recent years have revolutionized its possibilities. In Ra- for business until one served eagerly welcomed dio, Television, Aviation, Automotives, Refrigeration, Moving Pic- apprenticeship. But as in other professions by large manufac- tures, Super -Power, Lighting- Electricity is the key. Here is a vast there seems to be some advantage in learn- turing concerns. field for you, with unlimited opportunities. Now is the time. Start Through its Ex- FREE! on the road of Electrical Training that leads to bigger pay -bigger ing general principles in a school and prac- tension Division this opportunities -and SUCCESS I in great Electrical Write for free illus- tical details an office. School trains you trated Catalog EARN Cash In on your Electrical Even if one does not take a professional for advancement Practical Electric-- AS YOU LEARN Training while you're learn- and MORE PAY in ity -the Key to Suc- ing. Many students report increased earnings, advancement, even business course, there is something to be Electricity. One of cess"- and full de- while studying. Train in your spare time at home. Employment Serv- said for a general college education, pro- the most complete tails of Extension ice renders FREE aid for life. Lifetime Consultation Service. and practical cours- Division Training. Many exclusive features available nowhere else. Mail the coupon vided courses are chosen which are related No obligations. Send today for full par- es available any- the ticulars. ME. MO MN* MD OM MI gad.. to the world of men and affairs. Courses where ! coupon TODAY! in economics are peculiarly adapted to that COMPLETE LABORATORY OUTFIT is included SCHOOL OF (ENGINEERING without extra cost ! Enables you to "Learn by Doing." Milwaukee, Wisconsin end. One's education ought to initiate one Please send me without obligation into the intellectual life of the world. When FREE illustrated catalog, "Practical Extension Division Electricity - the Key to Success," the learning of the world was limited to a and details of Extension Div. training knowledge of ancient literatures, no one SCHOOL of ENGINEERING Name could be called an educated man unless he Dept. 20 Milwaukee, Wisconsin Address shared that knowledge. Without it he could UMW, .AIM .Ams_ not understand the language of educated .r a men, nor enter into their thoughts and feel- ings. To an increasing extent, the world is thinking and talking about great economic questions. The "thoughts that shake man- kind" are economic thoughts : the revolutions and the attempted revolutions of the world are economic revolutions. To enter intelligently into the thought of the world one must have some training in economics. To achieve any kind of constructive lead- ership in this field, or to be able to direct the thinking of the world into constructive channels, requires specialized training in economics. I emphasize economics for no other reason than that it is my special interest. Courses in history, in government, in mathematics, and in all the sciences which underlie the technique of production, should all be positive aids in the grasp of business principles.

The Modern Sherlock Get Holmes Auto Out 20 OTHER BIG CASH PRIZES GIVEN AWAY (Continued from page 413) Anyone with a sharp eye may win Solve this puzzle and solve it quick. is of Field Take a pencil and draw a line showing powder is used, and if the object very this BIG CASH PRIZE of $2000.00 how the auto can be driven out of the light in color, a bronze powder is dusted field pictured above. There's all kinds HERE, and in addition a brand new HUD- of fences in your way and there's only over the surface. Finger -prints on small SON TOWN SEDAN for promptness, one gate out of the field, but if your objects are revealed by dusting the surface I* May eyes are sharp you MAY find a way So//o**nBe if on time -or $3500.00 In all. Why through the various gates in the fences lightly with powder applied with a brush. not you? Think of having a new and get your auto out. If a bullet is found lodged in the wall or OURS HUDSON TOWN SEDAN given you If you find the way out, cut out ceiling, it is carefully extracted by using the puzzle and SEND YOUR for your very own, and $2000.00 in CASH to do ANSWER QUICK the tools provided in the kit. Care is taken with as you wish, or if you prefer, $3500.00 in all. Remember, all these BIG CASH PRIZES in removing the bullet, a rather large hole and thé new Hudson Town Sedan are to THIS IS NOT A MAGAZINE CONTEST be given away as a part of our big adver- cut completely around it so as to preserve Who tising campaign. You might lust as well Anyone Can Solve Puzzles May Win have the $2000.00 and the Hudson too, as certain tell -tale markings which are im- We are spending $125,000.00 to advertise the name and products of anyone else, and if you are keen enough to passing through the Paris-American Pharmacal Company and make them better and prompt you may win. Send your parted any bullet after known. We will give away a first prize of $2000.00; a NEW HUD- answer today, and we will forward you at the barrel of a gun. Bits of hair, cigar SON TOWN SEDAN for promptness, and 20 OTHER BIG CASH once complete rules of this prize offer. prizes -That's not all. We will award hundreds of others with $1.25 telling you of your success, how to get the ashes, threads of cloth, and the like, which worth of our goods, and duplicate prizes in case of final tics. $2000.00 Cash, first prize, and make the must later be examined are placed in test Remember you do not have to buy or sell any magazines to win any Hudson yours. There will be no delay in of the 21 CASH PRIZES. You have everything to gain and nothing giving you your award, so mail your tubes and brought back to headquarters. to lose by solving this puzzle and sending your answer quick. answer at once. A mirror and a flashlight enable the detec- PARIS -AMERICAN PHARMACAL CO., 5th and Court Ave., Dept. S15A, Des Moines, Iowa tive to look into inaccessible corners.

www.americanradiohistory.com 466 Science and Invention September, 1929 How a Roller Coaster Demonstrates Relativity By Donald H. Menzel, Ph. D. (Continued from page 425)

of one object to move against the tendency ciple, it is plainly more unnatural for the of another to do the same thing. car to swing up hill than to fall ór remain P. -I see my difficulty. Really the ten- motionless. Therefore my weight, or the dency of an object to move and my hypo- apparent force of gravity, is greatest under thetical force are one and the same thing. these conditions. It is not legitimate to speak of them sep- P. -But it is very easy to explain these arately. (Fig. 2.) facts without the help of relativity. Former Plasterer R.- Exactly. You have never seen R. -I am quite familiar with the ex- gravitation. You cannot tell me whence planations, but I must remind you again it comes or how it acts. All you can say that the various laws you are about to Now Earning is, "If there is a force, an invisible, intan- enunciate are little more than statements gible force that makes bodies attract one of what we observe. Pardon me for dis- $12,000 a Year another, then they will tend to come to- agreeing with you, but I do not think it gether, a stone to fall, for instance." Your "When I enrolled with the International Cor- easy to explain these observations on the respondence Schools,.I was a plasterer and I assumption that the force is attractive in- basis of modern physics. didn't know a thing about blueprints. Today stead of repellant is simply clue to the fact I have my own contracting business and I am that you observe bodies tend to approach P. -But we can foretell these events ex- able to figure the most difficult jobs and exe- actly. cute them to the satisfaction of everyone con- each other instead of to separate. cerned. My income is between $12,000 and P. think I begin to understand. The R. -A man drops a monkey wrench $15,000 a year. It certainly was a lucky day -I from an airplane. You can calculate the for me when I sent in that I. C. S. coupon." savages note the sun goes south in winter. That's a true story of what just one student of the Everything freezes. When the sun re- path the object will take, how fast it will International Correspondence Schools has done. Every fall, where and when it will strike. Yes, mail brings letters from other ambitious men and wo- turns, the earth blooms again. Their super- men telling of promotions and increases in salary due stitious minds sought for some explanation the law of gravitation tells you all these directly to spare -time study. things. But you have not told me why the One hour a day spent with the I. C. S., in the quiet of the observed fact, hence they decided of your own home, will prepare you for success In the that the sun was a god who smiled upon wrench falls. Gravitation is as mysterious work you like best. and who became angry as ever. You have borrowed from Peter Mail coupon for Free Booklet them each summer in winter. Their theory accounted for the to pay Paul, and, by doing so, have only INTERNATIONAL CORRESPONDENCE SCHOOLS observations every bit as well as do our postponed slightly the day of judgment. "The Universal University" modern ideas of the nature of the sun. A Why does the earth attract or at least Box 6194 -F, Scranton, Penna. monkey- Rela- Without cost or obligation on my part, please send me theory, obviously concocted to fit the facts seem to attract the wrench? a copy of your 48 -page booklet, "Who Wins and Why," is tivity is an attempt to dig more deeply into and tell me how I can qualify for the position, or In the should fit the facts, but that it does so subject, before which I have marked an X: no proof of its truth. So with gravitation. the nature of things. TECHNICAL AND INDUSTRIAL COURSES why objects Architect Automobile Work It was developed to explain P. -But there seems to be an obvious Architectural Draftsman Aviation Engines fall. Therefore we cannot legitimately re- explanation for your apparent loss and Building Foreman Plumber and Steam Fitter Concrete Builder Plumbing Inspector verse our reasoning and say that the ob- gain in weight. The track of the dip -the- IQ Contractor and Builder Foreman Plumber served fact of falling objects is a proof dips is highly curved. Here, I'll draw you C] Structural Draftsman Heating and Ventilation Structural Engineer Sheet -Metal worker of gravitation, any more than the savage a picture (Fig. 5). Now when the car is Electrical Engineer Steam Engineer Electrical Contractor Marine Engineer could argue that the recurrence of summer swinging around a curve, a certain amount Electric Wiring Refrigeration Engineer and winter proves the sun to be a god. of centrifugal force is developed that Electric Lighting R. R. Positions Electric Car Running Highway Engineer R.- You're on the right track. Now for throws you toward the scales when you are O Telegraph Engineer Chemistry when you are at B. This Telephone Work Pharmacy the "Dip- the -Dips," where I think I can at A and away Mechanical Engineer Coal Mining Engineer a little more graphic. explains why your weight is greater in the Mechanical Draftsman Navigation Assayer make the subject Machine Shop Practice Iron and Steel Worker (Opens suitcase and takes therefrom a former instance. I could calculate in ad- Toolmaker Textile Overseer or Supt. small "bathroom" scale. Puts it on the vance exactly what the scales would read Patternmaker Cotton Manufacturing point of the track. p Civil Engineer . Woolen Manufacturing of one of the cars and sits down at every Surveying and Mapping Agriculture Fruit Growing seat Bridge Engineer Poultry Farming upon it. *) R. -I'll grant that you could tell me the O Gas Engine Operating Mathematics Radio R.-According to relativity, as you well figures. But how about the scales? Can BUSINESS TRAINING COURSES so it Business Management Business Correspondence know, the apparent force acting on a body it handle arithmetic and algebra that Industrial Management Show Card and Sign to disappear when the object is will know just where to set its pointer? Personnel Management Lettering is supposed Traffic Management f7 Stenography and Typing allowed to "take its own course." Now, When you make your computation you (]Accounting and C.P. A. El English what would be the most natural path for say, "So much of the deflection of the " Coaching Civil Service Cost Accounting Railway Mail Clerk myself to follow? scales is due to gravitational force, so Bookkeeping Mail Carrier force," and you add or Secretarial Work Grade School Subjects L. all supports and obstacles were re- much to centrifugal El High School Subjects -If that Spanish French O you would fall toward the center subtract the two. We have noticed Salesmanship Illustrating Cartooning moved, no between the Advertising Lumber Dealer of the earth. the scales made distinction various forces. This behavior is more in Name R. car is starting. Note that my -The : that the car's Street 3). accord with my explanation Address normal weight is 175 pounds (Fig. most natural path would be toward the The physicist would say, I am sure, that City State center of the earth. If allowed to fall the earth is attracting me with gravita- freely no force would be felt on it or in it. Occupation tional force of 175 pounds. Here we are is made to If you reside in Canada, send this coupon to the The forces arise when the car International Correspondence Schools Canadian, Limited, at the top- Now watch the pointer . . . deviate from its natural path by some ob- Montreal, Canada (The car sweeps dizzily down the struction, in this case the track; the grade.) greater the deviation the greater the appar- L.-Twenty -five pounds! ent force. Cert AZi popularity,/ R -I think you will agree that the car L. -But why is it "more natural" for a and eaves to more nearly followed its most natural path body to fall? I do not feel that you have when it went down the incline than when made any simplification. I see that gravi- .earn to Play it was standing still or moving uniformly. tation does not really tell us why an object In ten days you start play- Consequently the apparent force of gravity falls, but neither have you told us. You ing popular airs on your motion is more new Pan -American saxo- as evidenced by my weight was much less. must tell us why downward phone, clarinet, trombone If the car had been allowed to fall freely, natural than upward. or any other instrument.- You'll be in demand - the scales would have read zero. Now knew would come to that you'll lead in popularity R. -I you wherever you go. watch. question sooner or later, and, to be per- now Act -write today for up a steep incline.) it ; not FREE illustrated catalog (The car careens fectly frank, I have been dreading and get our easy payment L.-Two hundred and fifty pounds. because it cannot be answered but because plan and Free Trial Offer. it is difficult to explain in elementary Pan - Americans are the R. accordance with my general prin- very only moderately priced, -In language. factory guaranteed band instruments in the world. the Write to: a Since the question may be raised, we should P. -The mathematical part of theory PAN -AMERICAN BAND remark that the relativist and the manager of the enters here, does it not? INSTRUMENT L CASE CO. amusement, park were great friends. The latter to make the diffi- freely gave permission and arranged for the per- R. -Yes. And I'll try 905 Pan -American Building analogy. Elkhart Indiana formance of the various experiments. (Ed.) culty plain by means of an Sur-

www.americanradiohistory.com September, 1929 Science and Invention 467

veying a piece of land is a simple task to through space alone, the wrench will fall a surveyor. Suppose that an engineer is in the straight line AB, striking the earth laying out a farm. The owner of the land, at B, say 1,000 feet below, one minute later. although entirely ignorant of geometry But A and B both have progressed through and trigonometry, does not wish to be one minute of time. Representing this by Give Strongfort A cheated and asks that the process of meas- the horizontal direction, B will have pro- urement be explained. This turns out to gressed* to B' during the minute. be a very difficult task, for the man is Chance To Restore extremely ignorant of mathematics. After The "world line" of the falling wrench some trial, the owner admits defeat and will be AB'. After it strikes the earth it remains motionless in space, though it decides that he will have to accept the sur- progressed Your Shaky Nerves veyor's measures faith. in time to B ". If, however, the on solid earth had not prevented, it would If your nerves are all a jangle; It is much the same way with relativity. have gone to C" in the interval. Accord- if you are fearful of everything - afraid of everybody; if you have The mathematics of relativity are rather ing to Einstein then, the path AB' is the gloomy forebodings; if your di- complex ; although they are no more mys- most natural, the gestive apparatus is all dis- simplest thing that could ordered; if you suffer from all terious to me than arithmetic to you, it have happened to the wrench. Similarly sorts of ailments; if you are would timid and - nervous in society; take more time than we have at our B' C" is simpler than B' B ", but the earth if you haven't the manly courage disposal to go over every step in the de- prevents the motion. Nevertheless, to go after what you want -if the you are lacking in all the manly velopment of the equations of relativity. wrench, in an attempt to follow the attributes that win favor and For the present, you will have to take my "greased path" B' C ", success in life, you are to be presses against the pitied -you are on the toboggan, mathematics on faith. earth with a force that you call gravita- chinning swiftly into mental and tion, but physical chaos. Like the engineer, the relativist deals which actually originates in the geometry of world lines. There is obvi- with geometry. There is only one differ- ously ence. Where the a natural tendency for world lines of Do You Know surveyor deals with different objects space only- length, breadth, height-I deal to intersect. What This with time -duration-as well. In other L. --I think I understand it better now. words, I deal with four dimensions instead Your expression "greased path" helped me. Means? of three. There is nothing curious about Do you not mean that among all the pos- this.* The surveyor's world sible paths the wrench If you allow this nervous con- was built of could have taken, dition to continue, it is going to points in space, mine from points in space - AD or AE for example, the smoothest lead you on to utter demoraliza- route tion and disaster; It will drag time, events. It may be somewhat new for of all was AB'? you down and down -at first you to think of time as a geometrical rela- mentally and then physically R.- Correct. The wrench could have and then, worst of all- spirit- tion, but it isn't difficult. Take this dip - ually. You soon followed either of your will be a the -dips. The track we have followed is a paths only if some- shattered wreck, suffering the thing material, a gust of STRONGFORT torments of the damned, and it wind perhaps, had will be only a geometrical path in space. But we have Builder of Men matter of time caused it to deviate from its natural path. when, in hopelessness and progressed through time as well ; we are Now you are able to see why despair, you will become a dere- some minutes older than when we left our our ups and lict, an outcast, a poison booze victim or a degen- downs on the dip- the -dips apparently erate dope fiend; and then plunge down into the starting point. And we can represent our pro- black abyss. duced changes in the earth's gravitational dual path through space and time in geo- force. metrical form. Here's a Helping Hand (Next month, the Relativist Einstein was one of the first to investi- and his two Don't go on slipping further and further into the friends ride the Merry-Go-Round.) canyon of despair. Don't suffer all kinds of ailments gate the geometry of space -time. He and become a wretched weakling. Don't think your found that there were certain general case is hopeless. You are in no worse plight than * Note that I do not say gloved. I have sup- thousands of men have been who came to Lionel mathematical relations that this geometry posed B stationary in space, for the sake Strongfort for help and who found in his Course in simplicity. of STRONG FORTISM the real science of health and must conform to. Out of several alterna- strength, and who quickly turned face front and were tives he chose the simplest. This choice built up into real men again. was somewhat arbitrary. It is as though I might say to you, some time when you Strongfortism are at my house, "You are welcome to Science of Health and Strength in IMPORTANT leave any way that you please. You STRONGFORTISM harms no one: It helps everyone may climb through the chimney, jump out TO NEWSSTAND -that is the assurance given you. There are no READERS drugs, no dope, no patent medicine, no useless expen- of the window, saw a hole in the roof or sive contraptions introduced or recommended. You go out the door." Of course, you may order seed have no doubt about it-no matter how you've IN to eliminate all waste and heen fooled by pretenders and quacks. Get right down adopt one of the three former alternatives, unsold copies it has become to brass tacks -give Nature a chance to rebuild your but I think you would prefer the simplest necessary to supply newsstand waning powers. method. dealers with the actual number of copies Send for My Free Book So it is with Nature. While there are for which they have orders. complicated alternatives, it This makes it advisable to place an "Life's Energy Through Strongfortism" is a revela- seems that she, order with your tion of inside facts about the human body that makes too, prefers the simplest, for the various newsdealer, asking it a priceless possession to men seeking to banish him to reserve a copy for vitality sapping ailments and weaknesses unfitting predictions of Einstein upon that basis you every them for life's duties and consequent mental depres- month. sion. have been amply verified by Otherwise he will not be This book points the way to a newer, better, experiment. ** able to supply your copy. For your more joyous life. One of the chief consequences of the convenience, we WRITE for your FREE copy TODAY. Don't delay. are appending here- Use the coupon below. Relativity "World Geometry" is that ob- with a blank which we ask you to jects appear to attract one another, to a be good enough to fill in and hand first approximation, with a force that cor- to your newsdealer. He will then RTR®NGIF® T IN T TUTS responds to Newton's gravitation. That is be in a position to supply copies to PHYS(Cgy AND HEALTH SPECIALIST why I say, "The most natural path of an you regularly every month. If you DEPT. 948, -...NEWARK. NEW JERSEY. U.S.A. object is toward are interested the center of the earth" - in reserving your copy - -Send this Coupon the most natural because it is the simplest. every month, do not fail to sign ------this blank. It costs you nothing to Free Confidential Consultation There is another way of looking at the do so. matter. Einstein's geometry, as I have Mr. Lionel Strongfort, Strongfort Institute, Dept. said, dealing as it 948, Newark, N. J.-Please send me absolutely free does with space and my ropy of your book, `LIFE'S ENERGY THROUGH time, is a geometry of events. STRONGFORTISM." This does not place me under any obligation. I hare marked (x) before the sub- L. (interrupting) -I don't follow you at jects in which I am most interested. all. I still don't see how To ..Catarrh ..Overweight events and geom- Newsdealer ..Colds ..Weak Back etry can be related. ..Asthma ..Weak Eyes ...Headache ..Short Breath R. Address .. Rupture ..Weak Heart -Very simply. Geometry, among ..Thinness ..Lung Troubles other things, treats of lines. The orbit of ..Pimples ..Round Shoulders Please reserve for me ..Insomnia ..Stomach Disorders a body in space is a line. The track of a copies of :.Constipation ..Increased Height body through space -time is SCIENCE AND INVEi7TION every ..Rheumatism ..Muscular Development aline -a world ..Nervousness ..Great Strength line (often called a geodesic). A (Fig. 6) month until I notify you otherwise, and is the monkey -wrench dropped by the care- greatly oblige, Private Ailments less airplane mechanic. Considered as a path Nano

Name. . Age Occupation * The idea was developed to sonie extent in previous article. (Ed.) Street Address...... ** See last month's article. City State

www.americanradiohistory.com 468 Science and Invention September, 1929 Coal Miner's Job Safer Than Yours! By Alvin F. Harlow (Continued front page 411)

Government experts have had no respect known to the mining industry as permis- whatever for it, having repeatedly blown it sible explosives. These are the result of up with dust and gas, and inflicted other intensive study of the problem by the min- indignities. An explosion clue to anthracite ing and powder -making industries, and the dust is practically out of the question, the system first began to be used about 1902. ignition point of the anthracite dust and air About four out of every ten of the more mixture being so high as to make it im- disastrous mine explosions in this country probable that the dust will ever be fired have been the result of ignition of gas or in the ordinary processes of mining. dust by explosives. Black powder is the One of the greatest nuisances under- most dangerous of all. It ignites very Save Cigarettes ground has always been the gases -most of readily, and being in powder form, is very them noxious, even deadly to the human apt to be spilled in handling, and thus lay - add to smoking enjoyment organism, and some of them explosive the train for a serious explosion. It has when ignited. Fire damp, for example, the also a long, hot flame which is very apt to WHENEVER YOU WANT the comfort variable explosive gas, usually consisting ignite gas or dust. Very few coal oper- and companionship of a good smoke, press gas- the button on the EJECTOR and your largely of light carburetted hydrogen, be- ators whose mines are at all dusty or favorite cigarette, like a welcoming hand, came a nuisance early in the history of the eous now venture to use black powder. JUMPS OUT to meet you! Cigarettes are were killed before Dynamite is somewhat less dangerous fresh and firm in this case. industry, and many men its dangers were full understood. In the than black powder, but it too is very tricky No more fumbling for cigarettes-no more first primitive pits and tunnels, gases were stuff, especially when it has been frozen or waste through crushing! Live dealers every- it is heated or when it begins to age where sell the strong, beautiful, modern a problem serious enough, but if they had when EJECTOR. Satisfaction or money back. had the enormously complicated mine sys- a bit ; and it has a very hot flame. The permissible explosives vary more or Send $1.50 for Model "C" tems of today, extending several miles f rom mouth, they could not less in their formulas, but at present they THE LYONS MFG. CO. the shaft or tunnel have fought the hazard with the simple con- are all made to conform to certain stand- Dept. K Mt. Carmel, Conn. trivances then in existence. ards set by the Bureau of Mines. They The first clumsy attempts at forced ven- explode with a flame much shorter and being made four and cooler than that of black powder and much tilation of mines were When un- years ago; but fan ventilation cooler than that of dynamite. MMCGir five hundred confined they are difficult to ignite, and She One Hand American mines Perfect was not introduced into are therefore far less likely to ignite gas until about 1850. Previous to that time not CIGARETTE CASE and dust ; and many of them will con- our workings had been neither deep nor tinue to burn unless continually reignited. extensive enough to make artificial ventila- With their use accidental explosions are tion imperatively necessary. very unlikely to occur. Easy A hundred years and more ago there Although the use of these permissible were men employed called "candle watch- compounds is increasing rapidly, yet metal to PLAY in detecting The choice of Sousa and ers," who were highly expert mines and coal mines not gaseous or dusty leading artists. The keyy to by the appearance of the candle flame or mines in particular) still con- success for beginners. Easy (anthracite to blow, responsive in action, other open light the first hint of fire clamp tinue to use large quantities of black pow- crystal clear in tone. Special in 1815 Sir Humphry rules for patented features and more in the mine air. Then der and dynamite. But the specific than 60 years' experience are Davy invented his safety lantern, in which handling them and other safeguards thrown assurance of supreme qual- of ity. Yet they cost no more. the flame was encased by a cylinder around them today are such, that even with FREE TRIAL, Easy Payments gauze through which the gas could not high pressure production and with the on any band or orchestra instru- very recent years ment. Write for special offer. penetrate. This was until mines extended into vast labyrinths strung Dorothy Mention instrument desired. considered the greatest boon ever devised with trolley and light wires, the hazard Johnson C.G. Conn, Ltd 956 Conn Bldg. talented for miners. But even it was not perfect. from explosives is not increasing but is young Elkhart, Ind. happen to be not prop- artist If the lamp should rather decreasing. with her erly assembled or if the gauze should One of the chief reasons for this is the Conn WORLD'S LARGEST become torn, then it is no longer a safety care used in handling and trans- Saxophone MANUFACTURERS eI extreme r HANDINSTRUMENTS lamp ; and furthermore, the gauze prevents portation. Magazines are strongly built, its giving forth a very brilliant light. barricaded and guarded and are remotely In recent years carbide or acetylene lamps located. A recent clever idea is that of YOUR IDEAS have been much used, but these also have making the magazine roof of a special can bring you immediate cash returns The latest and best six parts sand to without cost of patents. Manufacturers will their disadvantages. concrete consisting of pay cash and royalties for good ideas. Send. idea for the individual light is the electric one of cement. This would crumble to $5.00 for information how to sell your ideas lamp. This gives the most brilliant light in case of an explosion in the maga- to manufacturers and for contract form dust that will protect you. of any yet devised for use in mines and is zine, and no large chunks of material P. A. BENEDICT, 3291 Romulus Drive by all odds the safest. It is worn in the would be thrown about the neighborhood. Loa Angeles, Cal. usual place on the front of the cap and is Specially constructed closed cars are used connected by an insulated wire with the to transport explosives in and around the storage battery, which is preferably fas- workings, and are usually preceded by a tened to the back of the man's belt. The man carrying a red light. In these cars battery casings of approved lamps are pro- no metal is used on the inside. A lining of vided with locks ; first, to prevent malicious thoroughly seasoned wood, attached to the ; to Send your name and address for free booklet giving interesting in- tampering with the battery second, body by wooden pegs and wedges, covers formation and vital facts about Advertising. Find out how wo rn.pare Sou at borne bison:. spare time. for the opportunitiee open In this prevent the use of the battery for firing all inside bolt -heads and other metal parts. tinting busineee. Practical work. No test book.. Old estab- ig- lished Joist the pian oa blasts ; and third, to prevent accidental A layer of asbestos comes next and is held always wanted sWrttetoday. No obligation. nition of explosives by inadvertent contact in place by a second wooden lining, also PACE -DAVIS SCHOOL OF ADVERTISING thorough Dept. 1426, 3601 Michigan Ave.. Chicago, U.S.A. with the battery terminal. fastened with wooden pegs. Thus The lamps are turned in at night to the insulation is secured and there is no danger lamp room and their keys are also kept of explosion from contact with live wires. G?'tisBOOK10f by the lamp room attendant. A card in- A severe test was made of a car of this dex of the miner and his lamp record is kind at an Illinois colliery. It was filled Amaze and Mystify Your Friends! was Earn money at Clots and Parties. kept by number. No matter what happens with kegs of powder and loose powder No skill required. It's easy. The will never let his lamp poured all over and between the kegs. The Book of 1000 \Venders" tells how and below, the miner teaches you many startling tricks of get away from him ; and in case of ex- doors of the car were closed and copper Magic. Also contains a complete serves to the body in all direc- catalog. Send 10c. today. plosion, the lamp number often wire wound around LYLE DOUGLAS identify its bearer's body. If a man's lamp tions. A current of 275 volts was then Station A -3 Dallas, Texas is not turned in at the end of a working turned through the wires ; but though the shift, the lamp house attendant at once sides of the car were charred and some of gives his name and working place to the the wires melted, no explosion resulted. foreman of the following shift, so that he At least one State now has a law against may be looked up, lest he may have suf- carrying explosives in mine cars hauled by i con make. agood penman of you at home during True electric locomotives, and many mines forbid spare Ume 'Write for my FREE BOOK. NOW TO fered an accident. BECOME 0000 PENMAN." Your Darn* Another great advance in safety has been it. Men are not allowed to carry more than on e Write ttooda into the F.W.TAMBLYN. 42I Ridge Bldg., K City. MO. brought about by the invention of what are one day's supply of explosives

www.americanradiohistory.com September, 1929 Science and Invention 469

mines, and there are many strict regulations .ld regarding blasting. In some of the most up -to -date mines the blasts are not fired by , the miner himself but by a shot- firer -a man appointed solely for that work because of his long experience with explosives, q-111 sa expertness in testing the air for gas before "W firing a blast and general temperamental =t:' fitness. The miner may be allowed to carry sat s.r_ - ft., 1 his day's supply of dynamite or other ex- Á rr+. : plosive to his working place, but detonators are entrusted only to the shot -firer, who ghere . an air of must account for every cap and make for- hospitality that you 'll /i/re mal report of every one that is defective. AT THE HOTEL At many mines all blasts are now fired , just at the end of a shift, or if there is no PI CCA U I LLY night work, they are set off after the men 227 WEST 451/ ST. of BROADWAY quit work for the day. The use of hand - CHEW YORIÓ lighted fuse is decreasing rapidly, being ADJACENT To FvvRYACnvnY replaced by electric firing, which is posi- 4500 Ri IG}IT SUNIJT ROOMS tive, instantaneous and permits the men to EACH WITH DATH, - . be ill safety before any move is made to CLECTRIC FAN, ICE WATER explode the charge. The battery or blast- SINGLE ROOM"... BATH Saes ing machine is locked, and no one but the DOUBLE ROOM"No DAM $visa Exceptional Restaurant & Grille shot -firer carries the key. WIRE AT OUR EXPENSE FOR RESERVATIONS F.D.SOFIELD -M.w.aTfl D,arcroa The greatest difficulty found in dealing with the hazard of explosives is that of inducing the workman to treat them with due deference. Nowhere has the adage that familiarity breeds contempt been more EARLE E. LIEDERMAN -"The Muscle Builder' New beautifully demonstrated than in the miner's Author of "Muscle Building." "Science of Lyres Auto Finish tliw," `Secrets of Strewth," "Here's Health,' attitude towards the peevish and touchy "Endurance," etc. LOO in Color agents used in blasting. Here is one re- Here is just what every car -owner has long lation where it would be supposed been waiting for-an easy-flowing, quick - that drying Auto Finish in a choice of 15 brilliant, familiarity would breed respect; but in- MUSCLES permanent colors. "ELASTISHINE" is quickly stead, we find that the old -style miner applied right over the 5 Cents Apiece present color. Makes old, would (and does yet at mines where he is shabby cars look like new not properly coached and restrained) work Wouldn't it be great if the could buy muscles by Guaranteed for 1 year the bag take them home and paste them on our against cracking, chipping, around loose black powder with a pipe in shoulders? Then our rich friends. with money to peeling. Amazing! Sensa- his mouth; punch a hole in a powder can buy them, sure would be socking us all over the lots. tional! with a blow from the point of a pick; open But they don't come that easy, fellows. If you want muscle you have to work for it. That's the $90 WEEKLY cases of dynamite with a hatchet or a reason why the lazy fellow never can hope to be hammer and chisel, both likely to cause a strong. So if you're lazy and don't want to work Agents! Salesmen! Distrib- you had better quit right here. This talk was never- utors! Here is THE auto spark if they strike a nail; send dynamite meant for you. finish for the car owners- down into the mines in the original box nothing like It Anyone can apply it Comes in cans with the lid removed, furnishing a fine op- I Want Live Ones ready for instant use. Amaz- portunity for somebody to stand over it I've been making big men out of little ones for CAUTION Plan col - Don't confuse "ELASTI- ing Order lets you with a lighted candle or torch and start an over fifteen years. I've made pretty near as many SHINE" with liquids that lect your liberal profit. We strong men as Heinz has made pickles. My system merely brighten the original deliver. Write quick for explosion ; put frozen dynamite inside his beautiful Folder and FRED never fails. That's why I guarantee my works finish and fail to cover to it ; crimp detonating caps full Offer. shirt thaw to do the trick. That's why they gave me the name "rough spots." of highly explosive fulminates with his of The Muscle Builder." I have the surest bet SOUTHERN PRODUCTS CO. that you ever heard of. Hopkinsville, Ky. teeth; throw a sack of dynamite down a Dept. 43 bank rather than have the trouble of carry- What I'm Going To Do ing it ; cut fuse so short that if he stubs In just 30 days I'm going to increase your arm CARTRIDGE PISTOL his toe as he runs for shelter, he may not one full inch. Yes. and add two inches to BLANKProtection against Burglars. Tromps. & Dogs Speelal Offer your 1 Blank Cartridge Pistol arrive; stuff sticks of dynamite into several chest in the same length of time. But that's noth- (' ,....,;_...1110 Blank Cartridges ing. I've only started; get this -I'm going to put 1 a60 -page Novelty coat pockets or a bundle of them Catalog $1 carry knobs of muscles on your shoulders like baseballs. I a50 swung under his arm, put blasting caps I'm going to deepen your chest so that you will Well made and ] The Lot into another pocket and a coil of fuse double your lung capacity. Each breath you take effective, mod-m shin will flood every crevice 1 tee! '43.7....21.,""-, s around his neck and thus laden, go stum- of your pulmonary cavity tappearanceype off Revolver; C ÓOnly n with oxygen. This will load your blood with red appearance alone Is Cash bling through dark tunnels or climbing up corpuscles, shooting life and vitality throughout buráiLt hen'iou dIt _ - -- and down ladders, when a slip or fall your entire system. I'm going to give you arms might set off a blast that would wreck the and legs like pillars. I'm going to work on every p'o inner muscle as well, toning up your liver, your edge. evart- mine, and leave perhaps not even a trace heart, etc. You'll have a snap to your step and a where.5Special ecial cash with it. flash to your eyes. You'll feel the real pep shooting order often 1 Piss of the human cartridge which caused 100 Blank Cartridges,, led ournCartridge O ge up and down your old backbone. You'll stretch out De Luxe Catalog of latest novelties; all for ONLY your big brawny arms and crave for a chance to $1.50. Shig dhyEO r a ly. Cannot go br Among the ironclad rules now framed v rc 1 t, Extra Blank Cart)ridges 50c per 100. crush everything before you. You'll just bubble vp to overcome this form of carelessness are WtS over with vim and animation. JOHNSON SMITH & ZOrgelPANY,platDept. 268, O ACINE. clauses forbidding the carrying of caps and Sounds pretty good, what? You can bet your old ukulele it's good. It's wonderful. And don't forget, fellow -I'm powder or dynamite together ; imperative not just promising all this -I guarantee it. Well, let's get orders that boxes of explosives must be busy, I want some action -so do you. opened with a wooden mallet and wooden Send for My Free Book wedge; specifying the length of fuse to be used; directing that fuse must be tested `"1Xl[t6cactIaleadofHtettit-, every two weeks for speed of burning; in- Make money taking pictures. Prepare quickly during spare time. Also earn while you learn. No experience sisting that men handling explosives must -IT'S FREE- necessary. New easy method. Nothing else like it. be English; forbidding the Take it and read it. It's the peppiest piece of literature Send at once for free book, Opportunities in Modern able to speak You ever flashed your glimmers on. And 4S full -page photos Photography, and full particulars. use of frozen dynamite, and many others. of myself and some of my numerous prize -winning pupils. AMERICAN SCHOOL OF PHOTOGRAPHY This is the finest collection of strong men ever assembled Dept. 1426, 3601 Michigan Ave. Chicago. U. S. Af To supplement this rule -making, a con- into one book-Look them over- Doctors, lawyers, mer- tinuous campaign of education is being car- chants, mechanics, and every line of trade you can think of. I swear you'll never let this book get out of your hands ried on by the National and State mine again. And just think- you're getting it for nothing. bureaus, explosive manufacturers and trade Don't hesitate -there's no string attached to it. Grab it. Take your pen or pencil and fill out the coupon -But do journals. it now -before you turn this page. By these various means the danger from EARLE E. LIEDERMAN Wonderful, new device, guides your hand; corrects your writing in few days. Big improvement in three explosives has been reduced to a minor Dept. 2709 305 Broadway New York City hours. No failures. Complete outline FREE. place among mining hazards. During a Write, C. J. OZM ENT, Dept. 44, St. Louts, Mo. EARLE E. LIEDERMAN, recent ten -year period, when an average Dept. 2709, 305 Broadway, New York City of more than 900,000 men were employed Dear Sir -Please semi me absolutely FREE and without Houdini Debunks Spiritualism in any obligation on my part whatever, a copy of your latest The master magician now describes how the the mines of the United States, the book, "Muscular Development." (Please write or print spiritualist fools the public -all in this big, well deaths from the use of explosives averaged plainly.) illustrated book. Size 9" by 12" -112 pages. Book 216 per year, or one for every 4,279 men Name Age complete, only 50c. Send for it today to EXPERIMENTER PUBLICATIONS, Inc. employed. In a group of ten of our larg- Street 381 Fourth Avenue, New York City est cities, persons were killed in almost the City State

www.americanradiohistory.com 470 Science and Invention September, 1929

same ratio by automobiles ; and this hazard increasing efficiency and decreasing the is increasing rapidly, whereas the death number of accidents. As a fire extinguish- /ate from explosives in mines is slowly er, rock dust is said to be safer than either decreasing. Today, therefore, the average water or chemicals. citizen runs an even greater risk of being killed by an automobile than does the miner As to the expense, it is claimed that in by the explosives which he uses daily. British mines rock dusting costs only one - tenth of a cent per ton of coal mined. In Dust explosions were formerly harder to America its cost as spread over a period of combat than those of gas ; but in recent years will probably be no more than one years a remarkable discovery has gone far cent per ton. Some mines are now using towards controlling them. This idea, when what they call "mudite," a mixture of rock fully and properly used, will practically dust with a little earth and plenty of water, eliminate the hazard. The remedy is rock - which is sprayed on the walls of the mine, dust. like paint, where it hardens and stays in place better than the dry rock -dust. In For a long time the only device that . START TO PLAY anybody could think of to keep down coal some cases a coating an inch thick has dust was water. Now, water is highly been applied, and in addition to its other VERY FIRST DA desirable when drilling rock, especially in functions, it is said to act as a preservative mining, to hold down the sharp - for the mine timbers. Even if you can't read a note of music right now, metal you play a simple melody on the very day you get pointed siliceous dust which gets into the Free, easy lessons show The Bureau of Mines, as well as other your Deagan Xylorimba. lung's and tends to bring on miner's phthisis authorities, that majority of you how. Soon you are amazing friends and relatives. But it is extremely diffi- declare the Then a new life begins -long, happy evenings of joy; parties; and tuberculosis. accidents are preventable, and are due to popularity; radio engagements -and the same chance to cult to wet coal dust. It has been proven make $5 to $25 a night as Ralph Smith, Chicago-"Played forgetfulness, carelessness or deliberate ig- 20 minutes at wedding,¡ received $20." Or the Hellmann that sufficient coal dust will lie dry upon family, Reading, Pa.,- Made $300 in 5 weeks, spare time." noring of safety rules and instructions. the surface of water to cause an explosion The greatest difficulty is that of keeping FIVE DAYS' FREE TRIAL -Our big FREE book if thrown into the air. It is also impossible tells all about this fascinating instrument -the 5 -day free the human mind constantly on the alert triel offer -the free lessons -the easy payment plan. Send to make coal dust stay wet in a mine in the coupon today -the booklet will be mailed promptly against danger. Among men who come in without cost or obligation. through which the necessary ventilation contact with hazards daily for years, there currents are constantly passing. MAIL COUPON TODAY is not only forgetfulness but a disregard The. only expedient left was to nullify of danger amounting to contempt. Many J. C. Deagan, Inc., Dept. 1566, 1770 Berteau Ave., Chicago the explosive tendency of the coal dust. It a miner will calmly step over a barrier Send me, without obligation, full details of Free Trial offer and easy -payment plan on the Deagan Xylorimba was found that this could be done by mix- upon which a danger sign is hanging and Naine ing rock dust with it. The specific heat walk into the forbidden entry, confident of rock dust is low, and when half -and- that the danger is exaggerated, and that Address half mixture of rock and coal dust is even if it isn't, he can take care of him- thrown into suspension in the air, the rock - self. At bituminous mines which are gas- dust absorbs heat and lowers the tem- eous the men are forbidden to take matches perature of the flame of propagation below or pipes underground; in some States this attá five professions the ignition point of the coal dust. Also is prohibited by law. But so persistently the particles of rock dust getting between do the men violate this regulation, that the particles of coal dust act as a cold many collieries in desperation, have found AIT and curtain, impeding the progress of the flame it necessary to search the men's pockets for from one coal atom to another. the tabooed article before they enter the. AD`VEIZTISI SIG mine. Meyer Both Company; a dominant It is declared that this remarkable rem- factor for 28 years in art and advertis- edy -which has begun to be employed only There are some foreign born miners who ing service, with over 5,000 clients in America, though some are unfamiliar with the English language, thruout the English speaking world, very recently offers practical instruction in these British concerns have been using it for and some illiterates who are unable to two fascinating fields open to both fifteen years -will eliminate at least 85 or read and digest the safety instructions men and women. This instruction- 90 of the dangers of a coal dust and advice offered them. Many of foreign based upon so wide an experience- percent translates the maze of vague theory explosion. Hereafter, such dust explosions stock are fatalists, who regard it as a into demonstrated fact. Individual- as may occur in coal mines should be small, waste of time to take precautionary mea- ized home study instruction. If in- by little if any sures for or against the inevitable. In terested in a career in either of these and trifling affairs, attended well paid professions send for free loss of life. their opinion, if a man's death is not sched- (1) or (2) Advertis- for he could lay a blasting cap book on Art (...) contain little uled today, ing(...). Thedust to be used should a -top of a can of nitro -glycerine and swing or no free silica, which is so detrimental a twelve -pound hammer on it with -perfect MEYER BOTH COMPANY to the mucous membrane. Either limestone MICHIGAN aLVD.AT 2OTILJT Dept. 64, CHICAGO confidence that nothing untoward will or shale is good for the purpose. It is' happen. Needless to say, it is difficult to ground extremely fine, and according to get this type of mind interested in safety the best practice a carload of it is sent measures or precautions. through the various tunnels at intervals of a week to a month, according to' conditions, It is human weakness, therefore, which spraying the stuff on walls and floor with counts to a considerable degree for the fact an air ejector. Some assert that even a that falls of material from roof or wall ten percent mixture of rock dust with coal cause the greatest number of deaths and dust will reduce the pressure and corre- injuries in the entire mining industry. A New sponding violence of an explosion by 90 About half the fatal accidents to men em- percent. ployed underground in coal mines and one - Lightweight As an additional safeguard, quenchers, or third of those in metal mines result from Electric Drill barriers of rock dust are placed at various this hazard; also a large percentage of the Sturdy and practical. Fully guaranteed for in a mine so as to confine an lost time. Many such accidents are diffi- S and points intermittent work.Weighs only 411bs.t explosion to a small area. These consist of cult to foresee, it is true, but it is never- Uses direct or alternating current, and is supplied to you for 110 to 125 volts. 200 to 250 volts or 32 volts. Special Jacobs light shelves near the ceiling piled with theless true that a miner will often fail to Chuck. Bore up to one- fourth inches. Stop and start switch in the handle. Comes complete with 10 feet of cord and rocket. rock dust, or boxes full of it suspended on examine the roof and wall in his working Price postpaid anywhere in U. S. A.- $18.75. or If not return pivoted supports. When an explosion of place for loose rock after a blast, or make andmoney beefu ded.l e spe= fy voltage used. WRITE FOR OUR CATALOG. either gas or dust occurs in the vicinity, the the inspection carelessly, perhaps tapping Jones Motrola Sales CO.. Dept. 209, 370 Gerard Ave., N.Y. air wave preceding the explosion upsets the the roof directly over his head with a pick box or shelf and fills the atmosphere with and bring down a loose flake or stone which large enough to kill him. NB PAINT SPRAY a cloud of incombustible material "DOES THE WORT' Paint Spraying Brinar smothers the flame. Some German miners Quick, Easy Profits -11B About 18 deaths in coal OF FIVE does work of 5 brush painters. even hang a small paper bag of the dust percent of the OP MEN" Paints autos, furniture, houses, at hole it is mines are due to haulage accidents ; that lowest prices, with big profits for you at the mouth of a drill after Pays for iteelf -only $ 2 0 monthly. Easy loaded. If the flame blows out of the is, men are struck or run over by cars, lowestones erais brings it. Practically crushed between cars or between cars and no investment. 30 days' trial. drill hole, the bag of dust, bursting, quickly EAT w rile for valuable bulletins quenches it. walls. Haulage causes relatively few fatal- jO DAYS TRIAL Hobart Brothers Co., ities but many disablements. Next come QUICKLY PAYS Box 209, Troy, Ohio. FOR ITSELF- Other benefits are derived from rock accidents from the use of hand tools, and dust. About 90 percent of the light under- after this, injuries from falls, accidents the To be sure of getting your copy each month, ground is absorbed in the blackness of connected . with machinery, electricity, subscribe to Science and Invention, $2.50 year. coal. Rock dust, especially if it is lime- shafts, cages and so forth. EXPERIMENTER PUBLICATIONS, Inc., stone, is so light in color that a tunnel 381 Fourth Avenue, New York City. coated with it is much better illuminated, (To be concluded)

www.americanradiohistory.com September, 1929 Science and Invention 471 Wood Turning By H. L. Weatherby In the September Issue of (Continued on page 432) AMAZING STORIES perfectly round piece of glass will be the esult. Turning the frame is done with the aid of a chuck and the whole process is face- GOLD DUST AND STAR DUST, plate work, which is a familiar operation by Cyril G. Wates. This time our to the readers of these articles. first prize winning author tackles The first step in the turning is to turn the fourth dimension -a favorite 1 the back surface of the frame cutting the subject about which so much is rabbet which holds the glass, picture and written and so little is known. It backing. This is, of course, taking it for is no wonder the author finds it granted that a picture has been selected necessary to put a detective on the job. and that the size is known ; and that a satisfactory piece of wood has been mounted on a face -plate for this purpose. THE PERIL, At RED by Capt. S. P. this time also the outside diameter and Meek, U. S. A. If it is interesting you pledge even the opening, can be cut square if to watch the advance of the Ma- care is taken that the frame does not jump chine Age, it is equally interesting yourself to secrecy we will off of the lathe and break up. A word and perhaps more of caution in important to give teach you the secrets of is order when considering a thought to the possibilities of fu- the opening. The cut should be made, ture warfare. Being an army man working from the middle out, otherwise himself, our author goes beyond Real Professional a border frame may be the the result. "war in the air" period and shows After cutting the rabbet at least, remove us possibilities far more the frame piece from the face -plate and dangerous. attach to the face -plate a block that can be used for a chuck. Turn this to the THE YOUNG OLD MAN, by Earl exact size of the rabbet cut, which is also L. Bell. When the meaning of elec- the glass size, and carefully fit the chuck tricity is discovered, many new, and to the frame. This should be a tight press today unthought -of, uses would fit, or the frame will slip during the sub- probably be found for it. For in- sequent operation, which consists in turn- stance, if by a strong enough elec- ing the beads, fillets or curves which make tric shock life can be taken away, the moulding. Cut the opening through, might it not also be a means if for this has not already been done, sand- making or perpetuating life? It is paper and the job is ready for finishing. an The interesting theme to play with writer cal-Mot help but feel that, for and Mr. Bell does so in a manner most small frames of this type, a dull absorbing to the reader. black finish is the most satisfactory. This is, however, entirely up to the builder, and a stain and varnish finish or a polychrome OUT OF THE VOID (an Dr. Harlan Tar inter- bell, internation-n- effect might suit better. ally own maai planetary serial in two parts), Part á teacher the II, by Leslie F. Stone. The con- world'lm . cluding chapters of this story gain ,nap ;cxin.. Plaques momentum as they proceed. The adventures of Dana Gleason on this AS another suggestion as to what planetoid beyond Mars are particu- may be done along the line of circu- larly fascinating Learn to be a lar because of the frames, the woodworker, who has a wealth of scientific detail that is lathe, may use it to get beautiful results included in the story. in making plaques. For example: The Magician writer has prepared a great many imita- For the first time in the history of Magic the tion miniatures by securing circular prints age -old, sacredly guarded secrets of the Mys- THE DOG'S SIXTH SENSE, by tic Art are being revealed. Now at last you representative of the miniature period W. Alexander. What is it that en- can learn to be a Real Professional Magician. (such prints may be secured from firms ables a dog to understand his mas- Yes, and you can learn this wonderful advertising in art magazines) and mount- ter's wishes and commands? What art easily and quickly AT HOME. You are ing taught the mysterious Principles by which them on the surface of a turned would be likely to happen if this the Professional Magician works. You are plaque, painting the curved surface with extra sense -and there must be one taught everything an ivory enamel or lacquer and the frame from wonderful im- -were combined with man's intelli- promptu effects to Earn $250 a black. After this had been allowed to gence? Much might happen -and massive stage illu- dry, the whole was given a couple of nilich does happen in the story. sions. But before to $1000 coats of varnish and rubbed. The effect you can study, you a Month is must sign the Magi- There's a big demand beautiful, the operations are simple, and cian's Solemn for Magic entertain- the possibilities are practically unlimited. THE WHITE ARMY, by Dr. Pledge of Secrecy. ment. Magicians get This means that big money. Dr. Tar - Paste may be used to fasten the picture Daniel Dressler. Even the layman bell gets as high as to the unpainted you are getting the $250 for a half hour's wood, or in case the wood is greatly concerned over the guarded secrets of work. Unlimited op- is painted first, varnish allowed to become mechanism and mechanical arrange- the Magic Profes- portunities for yon! tacky before the print is applied will hold ment of various machines. Only the sion. Thuile of thatl it in place. In any event the print will human machine seems to be taken probably require one or more coats of Write for Details entirely for granted and is treated Mail coupon now white shellac after setting; before it is NoSaleamen Will with a vast amount of indifference. Bother Tou! for the free Magic varnished, to act as a filler, before the Yet it is the most literature telling all marvelous ma- about the great Tarbell Course in Magie. Get our varnish is used on the outside. chine of all, and as yet has not been Low Prices and Easy Payment Plan. No sales- For truly professional -looking work, the capable of reproduction in even the man will ever can, bother or annoy you. turned frame answers the amateur's prob- slightest degree. Dr. Dressler, with Tarbell System, Inc., Studio 14 -26 lems, where it can be used, and it opens an expert's knowledge on the sub- up wonderful possibilities for the expres- ject, weaves a romance around it 1926 Sunayside Ave., Chicago, Me sion of ideas. worthy of anybody's careful study. Tarbell System, Inc., Studio 14-26

1926. Sunnyaide Avenue. Chicago, Ill. THE Gentlemen: Without any obligation send me your CORAL EXPERIMENT, by .free literature and information all about your won- DON'T FORGET TO Alexander Snyder. If you are a derful "Tarbell Course in Magic." Also tell me about dentist you will be interested in the your Low Prices and Easy Payment Plan. VOTE! story professionally. If you are not Name If you have not indicated to the a dentist, the interest will be en- personal. editors just what kind of articles you tirely Anyway, you ought Address to know what it is like best, don't fail to mark ballot all about. appearing on page 427. Age

www.americanradiohistory.com 472 Science and Invention September, 1929 Home Movies By Don Bennett on Nationally Popular (Continued from page 421) 2I -JEWEL -Thin Model road, the camera shifts, approaching the bombs are necessary, one exploded at the fork but on the other road is papa in his moment of impact and the other before you STl,1DEBAKER car urging his driver to hurry and catch start the camera when the wreckage is The Insured Watch those young fools. revealed. The only high -grade watch At the intersection is a line of trees that Going from the ridiculous to the sub- solddirect fromfactoryl screens each road, cars on one road can't lime, very pretty effects may be obtained Imagine being able to purchase these magnificent thin see cars on the other until they reach the with smoke -pots, as they can be used in model watches at lowest intersection. The camera shifts again, this many ways. There are several ways of factory prices on easy payments out of your income, or time so that we can see .down both roads setting the stage and carrying out the ac- forcasht Let us send you one and we discover the two cars rapidly ap- of these marvelous watch tion, but we will consider just one, an -you are under no obligation proaching the intersection -they pass the introductory episode for a film concerning to keep it. You'll agree it is the world's greatest watch trees and discover each other but are going a fishing trip. This episode also includes value. Write for free 6 -color too fast to swerve, they crash, a flash, and the main title of your film as well as the book and learn thetruefacts! a black pall covers the whole scene. It end and will not consume more than twenty slowly clears and we see the wreckage in or thirty feet of film. FREE the middle of the scene, papa and his chauf- The scene fades in on a man reclining feur ringed with tires, faces black and against a tree. He is dressed in outdoor 6 -Color Book sooty, their clothes in tatters, looking at If you write at once we will garb, various accoutrements of the fisher- send beautiful style book. each other. Over them in the background showing lowest factory prices man lying on the ground around him. He on these lifetime insured are the two kids running down the road, is sleeping but has been nodding only a few watches. Thousands save papa and the driver relax into oblivion and moneythis way. Write todayf minutes, as his pipe still smoulders in his we fade out. hand. A wisp of smoke arises from it. WRITE! Slapstick and hokum, you say. But from Luxurious strap and bracelet Near his feet is a fire on which he has watches at remarkably low such situations as this you will derive much evidently just piled some wood. As we prices l Write for free style fun and enjoyment, both in making and in ! watch it starts to throw out a heavy column book TODAY showing, and it gives one good experience WATCH COMPANY of smoke which gradually covers the scene. STUDEBAKER for tackling heavier problems of drama. A tiny wood -sprite emerges from the smoke Three- quarterStudebakera yof fa dealingor Let's analyze this episode from the pro- Dept. N11199 South Bend, Indiana and gestures that he is going to play a Canadian Address: Windsor, Ont. duction standpoint, and see just how it was trick on the fisherman, pointing down to the done. The first two scenes are easy, the position the fisherman occupied before the camera is mounted on the running board smoke obscured him. He reaches down and of the car for the moving shots. The ap- picks something up, it is a letter "F." He Build This Model Airplane proach of the two cars requires careful hangs it up on the air and reaches down YOURSELF timing and rehearsal as well as expert driv- again, picking up "I" and so on, until he ing. If your drivers are not expert enough has hung the words "Fish Stories" up on to handle the situation, have them start the curtain of smoke. Then he vanishes from a collision position and rapidly back and the words fade out. (Fig. 3.) away from the camera. The camera of course must be upside down for this shot, Here is how you do it. The fire conceals is lighted remote so that the cars going backwards will ap- a smoke -pot which by 3 -ft. model pear to go forward. Or you can use your control. If the smoke does not cover the set up, mask box (described in May, 1929, issue), whole screen, have a still camera BELLANCA "Columbia" cutting off half the scene for each exposure. covering the same angle as your movie True scale, exact replica, guaranteed to fly, This requires very careful timing or the camera and snap a still. The wood -sprite materials and instructions, $9.00. with all cars will not crash. Use it only if you is of course double exposed on the black GET YOURS ! cannot get the smash -up any other way. portion of the film against a black curtain Send for your copy of our 56 -page booklet Now comes the trickery. When the cars and the letters he hangs up are painted which contains the scientific knowledge we meet at the intersection they should both white on cardboard. The letters are hung experience in model and on a black wire or two wires strung in gained through 20 years' swerve so that they almost collide have airplane construction. It illus- then sheer off. The expressions of your front of the curtain and the cards describes famous must fit the scene of course. hooks on their backs for support. If the trates and actors scene, airplanes, also all parts required plant an old wreck so that it looks smoke has completely covered the experimenters Now in any by model builders, C like two. A trip to the local junkyard will you simply fade in on the sprite, and inventors. This booklet is portion of the scene, and he carries out his mailed to you upon receipt of.... secure a fine looking wreck for practically Your dealer can supply you. If not, write its. nothing. Lay some torn cloth on the wreck, action, until at the end, he steps behind a and disappears from sight. U. S. MODEL AIRCRAFT CORP. have eight or ten tires lying around and black "flat" the fade out. (Fig. 4.) 397 -399 -A Bridge St. Brooklyn, N. Y. any odd bits of junk that are available. after which letters Have the actor who plays papa bring an If the smoke has only covered part of the suit along and tear one sleeve out of scene, the sprite must confine his action to old a it, cut it into ribbons and wreck it com- that part covered by the smoke, and as safety precaution mask off the other por- Course for men of ambi- pletely in every way you can find. Do the tion and limited time.ime. same to the chauffeur's clothes. Blacken tion, so that it will not be fogged. The Electrical Over 5000 men trained. use of a gauze on the first exposure will Condensed course In Theoretical and Practical Elec- their faces and lay them in the wreck in trical as grotesque a position as possible, even heighten the beauty of the scene. Engineering the closely related upside down. Then put a short smoke -pot While our "sleeping fisherman" is still subjects of Mathematics and Mechanical Drawing. -pot, Students construct motors. install wiring, test elec- in the wreck and light it. It will lay a in position, we start another smoke trical machinery. Course designed to be completed heavy smoke over everything. As soon as fading in just before it is ignited, but with in one college gene. it has started to burn out, start the camera. the camera upside down. We then double BLISS This will give you a black screen and as expose again on our sprite, but this time he ELECTRICAL SCHOOL the smoke blows away your wreck will has the words "The End." This must also Prepare for your Profession In the made in reverse motion and therefore most interesting city in the world. appear and as soon as the smoke is cleared be Catalog on request. away sufficiently, start the boy and girl all his actions must be the reverse of the tilt 149 Takoma Ave.. Washington, D.C. have way they appear on the screen. Suppose running down the road. They, too, been concealed by the smoke. When all we want to fade in on the title, then have desirable action has been recorded, fade out. the sprite take the letters away and dis- Now for the editing. When the two cars appear, the smoke returns to the fire and - FREE BOOK TELLS HOW are closest together, cut the film and splice the fisherman ,wakes up and rubs Isis eyes. You can quickly qualify for po- on two or three frames of clear film. That Then, on the start of the scene, that is, sitions paying $50 to $250 a film where we fade in on the fisherman, -have Learn week in Motion Picture, Com- is the explosion. Then take the where mercial or News Photography the smoke has started to clear away and him rubbing his eyes and stretching, then and Projection, or start your own sleep. our PHOTOGRAPHY business. No experience needed. cut it about two feet before anything is he relaxes and goes to With Camera or Projector Given discernible through the smoke. Splice this camera still upside down, the sprite appears (04 Learn at home or In our great film is as if by magic, merely by stepping out from New York Studios. write for to the two clear frames and your and Big Free Book of amazing op- complete. A somewhat better effect is ob- the flat, which should be on another part portunities. Job Chart and hangs the letters up and Motion Pictur Camera or projector offer. tained by using a white smoke bomb which of the set and Projectio contains phosphorus and emits an opaque then we fade out. The effect on the screen N. Y. Institute of Photography is above. Dept. A -903, 10 W. 33rd St., New York white smoke screen. In this case two as described

www.americanradiohistory.com September, 1929 Science and Invention 473

Many other settings can be used with this as a basis ; in fact, a whole story can be carried through by merely fading out on the sprite and fading in on a story. This will be a dream sequence and is ended, the same as the other episode was ended, by having the sprite in pantomime express his i approval or disapproval of the story and then, as he disappears, the smoke returns to the fire and the actor wakes up in won- WHERE ,-'"{/. derment at his surroundings. A cut from '\\ reverse to normal action is easily made in LIN DßERGH a case like this by inserting a close -up to cover the change or discrepancy in match- ing the camera angle. The camera may LEARNED! then be placed right side up and ( the action resumed in normal direction. (George Blake and his shadow, Jones, We were absent this month on their respective We Can't Supply the Demand vacations, but a "wish you were here. Good movie weather" postal advises the Editor for Lincoln- Trained Men! that Blake is going to tell us a lot about capturing autumnal colors next month, both EXECUTIVES of big aircraft companies and airports call on us constantly for mechanics and pilots. We can't supply them with enough -the demand for in black and white and in color.) Lincoln -trained men is too great! So we want more students. We want you ! Come where Lindbergh learned! Let us train you to fill one of these Big Pay Jobs. Complete Ground Course-We put you correctly from the start. Learn to handle through a complete Ground Course on a plane safely under all conditions. Our actual planes furnished by the Lincoln training planes and pilots are all Govern- Aircraft Factory. Teach you to repair ment licensed by the U. S. Dept. of Com- Sport Plane Blueprints aero motors, emphasizing the Wright merce. Our pilots have taken up more Whirlwind. This is one of the few than 100,000 passengers from our airport Available at Nominal Cost civilian air schools possessing a Wright without a single accident. engine. We teach you to construct and Write Today for FREE full information repair wings, fuselages, ribs, etc. about courses, low tuition and the Story Complete Pilot Course -You learn to fly of Lindbergh training at Lincoln! If Complete Set of Blueprints of Lin. coin Sport Plane, $6.75. LINCOLN AIRPLANE SCHOOL WHERE LINDBERGH LEARNED Tr Gerber Monoplane Blue- -set of 223 Aircraft Bldg. Lincoln, Nebr. prints, $1.00. Send Orders to Blueprint Dept. SCIENCE AND INVENTION Money Making 381 Fourth Ave., New York City Opportunities I'll Start 'You Without a Dollar. Sell all wool highest value $19.95 You Don't Need Money You'll make $85 weekly, taking orders suits. 54.00 Commission. 9x 13 big or experience. We put you in Men's for finest shirts, ties. Free Outfit. Dept. samples, Line free. Davis- Rogers Shirt-Tie- Underwear Business. You PC 9, Roseeliff, 1237 Broadway, N.Y. Tailoring. 901 W. Adams. Chicago. make $4.50 every hour easy. Spare Big Money Maker Tailoring Line. WIthoutonecent investment make time or full. Write Now! Vanderbilt Pays 34 to $7 an order. Quality Suits, $65.00 every week selling finest work Mills, Dept 134 -P 29 W. 32nd Topcoats, Overcoats. Free suits to pants made. Every man buys 3 pair Street; New York, N. Y. producers. Giant outfit free. Dept. for $5.50. Outfit Free. Dept. L.C.S. 9, Earn $100 Weekly Selling Banks. PC -9, Olympic, 5th Avenue. cor. Longwear, 489 Broome St., New York. business, professional and society peo- 19th Street, New York. MakeBigMoney. Selishirtsandties. ple. America's greatest Xmas Greeting IN RADIO NEWS Win Big Pay with New Shorthand. Tailored broadcloth, 3 for $6.95, com- Cards. Large cash commissions daily. Written in ordinary A- B -C's. Learn mission $1.50. Beautiful Rayon lined liberal monthly bonus and samples to- its fundamentals first evening. Write ties. Outfit Free. Dept. BC59. gether with full instructions sent Free. for shorthand in few hours. Send for Free Big Bob. 489 Broome St., New York. II you want to earn $2,000 before Xmas September book! Speedwriting, Inc., 200 Madison Make Big Weekly Earnings. Be a apply now to Mgr., Dept. M -1, Procese Ave., Dept. BM -5242, New York, N. Y. children's wear specialist. Mothers buy Corporation, Troy at 21st Chicago. We Put You in Hosiery and Lingerie- on sight. Free outfit. Dept. PC -9. Bob- $100 weekly selling all -wool union business! Make $95 weekly. You don't by & Jane, 303 4th Ave. New York. made -to measure suits and overcoats at THE RADIO NEWS FOUNDATION need experience TUNER. A tuning unit embodying ex- or money -we furnish Hotels Need Trained Executives - $23.50 up. Build big repeat business. tremely everything -$40 worth actual samples. Nationwide demand for trained men Big Pay daily-monthly bonus extra. compact design and incorporating Noe -Equi, Dept. 113, Reading, Pa. and women; past experience unneces- Large samples Free. W.2 .Gibson, Inc.; the new A. C. screen -grid tubes, power If You Are 40 or More, and Want sary. We train you by mail and put 500 S. Throop, Dept. J-672, Chicago. detection, plug -in coils to cover a wide $35 weekly for dignified spare time you in touch with big opportunities. Something New range of wave- bands. This unit has been work, with splendid Guaranteed House- Write at once for particulars. No house to house canvassing. A designed especially for adaptability to a hold Products Line, Write Blair Labo- Lewis Hotel Training Schools; proposition in which you can build wide variety of uses; a feature to gladden ratories, 12 -M-14 Lynchburg, Va. Room BR-W637, Washington, D. C. up real business. No investment. Agents sell personal Christmas $8 Daily showing friends, neighbors Badger Company; Fort Atkinson. the heart of the dyed -in -the -wool radio Cards. Full comm. In advance. We de- our all wool made- to-measure clothes Wisconsin. experimenter. liver and collect. Samples Free. Hill $23.75. Everything furnlshedFree.Your $95.00 weekly selling union made - WHY NOT GET THE UTMOST FROM Studio, 272 Lafayette St.. New York. for to-measure, all -wool suits and over- RADIO ON YOUR PLEASURE BOAT? America's Greatest Tailoring line Fairrbanks 2307 Wabansia, hicago. coats at $25, $30, $35. Biggest commis- Lloyd free; 175 samples; guaranteed pure Agentsearnbigmoneytakingorders sions paid daily. Extra bonus besides. Jacquet points out some of the virgin wool: tailored to order; low Price; beautiful Dress Goods, Silks, Wash Write for details. Nearly200 pure -wool uses and pleasures -as well as some of big commissions daily; also cash bonus; Fabrics, Hosiery Fancy Goods. 1000 fabrics Free. Pioneer Tailoring C o.,Con- the pitfalls -of radio as it applies to get outfit now. Address Dept. 201, samples furnished. National Importing gress & Throop, Dept. J -1272, Chicago. pleasure- boating. Goodwear, 844 Adams, Chicago. Co., Dept. V 89, 573 Broadway, N. Y. Forest Ranger jobs pay $125 -$2Q0' SellThreeBeautifulDresses for$5.00 if you want to make $15 profit a day mo. Home furnished; plenty hunting. WHAT HAS BROUGHT RADIO TUBE with dollar profit Tor yourself. Amazing and get a new Ford Tudor Sedan free fishing, trapping. Write Norton Insti= PRICES DOWN? A pictorial description proposition-workers earn $35 to $75 of cost, send me your name immediate- tute. 1523 Temple Court, Denver. Colo. of the ingenious machinery and produc- weekly.Your own clothingFree.Malloch ly. No experience necessary. Particu- A Business of Your Own, Bankrupt tion methods which have made your ra- Frocks,Dept.9 -P, Grand Rapids, Mich. larsfree. Albert Mills. 3786 Monmouth, and Bargain Sales. Big Profits. We start dio tube dollar worth ten times what it A Paying Position Open to Repr. of Cincinnati, O. you, furnishing everything. Distribu- was a few years ago. character. Take orders Shoes -Hosiery Big Pay Daily, selling Shirts, Pants, tors, Dept.279, 429W .Superior, Chicago. direct to wearer. Good Income. Perma- Overalls, Sweaters Leather Coats. Women 18 to 45 wanting to increase FACTORS AFFECTING THE INSTALLA- nent. Book 'Getting Ahead" Free. Tan- Lumberjacks, Underwear, Hosiery, their income. Pleasant work. Will not TION AND SERVICING. OF SOUND ners Shoe Mfg. Co. 2149 C St. Boston. Playsuits! Outfit Free. Nimrod Co., interfere with present duties. 0 Write AMPLIFIERS. This is the second of a Sell 2 suits for $34.50. Big Advance Dept .85.4922- 28LincolnAve.,Chicago. Brown Co., Dept. A, Paducah, Ky. series of articles by S. Gordon Taylor commissions. Build permanent business. Make $12 a Day and get new Ford W't'd immediately. Men -Women. and takes up the practical angles which Become dist. mgr Liberal guarantee sedan Free, taking orders for fine, 18 -55, qualify for Gov't. jobs; $125 -$250 must be considered means 100% repeats. Rex Woolen all -wool, union-made,made -to-measure mth. Paid vacations. Thousands need- by local servicemen Corp., Grants Rapids, Michigan. suits at $23.50up. Biggest commissions ed. Instruction Bureau, 137, St. Louis. who wish to capitalize the decidedly We Start You Without a Dollar. paid. We train the inexperienced. Fine Free Suits earned by 67 men plus worth -while business in their communi- Soaps, Extracts, Perfumes, Toilet carrying -case outfit of large real cloth cash profits of $75.00 to $425.00. ties. Goods. Experienceunnecessary.Carna - samples free. Spencer Mead Co., Har- Nationally known line. Great Western DR. LEE DeFOREST WRITES THE REM- tion Co., Dept. 670. St. Louis, aio. rison Jr Throop Sts., D't.J -972, Chicago Tailoring Co., Dept. 305. Chicago. INISCENCES OF A RADIO PIONEER. All the way back to the early days of trying to put the first soprano voice on the air by means of an arc transmitter, as well as some of the pioneering which ZIP -ZIP LEARN TELEGRAPHY has lead to developments far afield from S H O O T E R Be an expert Morse WITH the original experiments. or Continental code Thousands of boys are made happy operator! BIG PAY- TELEPLEX FOR REAL THRILLS, GET DOWN IN with this wonderful Zip - Zip TRAVEL - FUN - shooter, scientifically and prac- ADVENTURE. After a few short THE AMATEUR WAVE BANDS. Lieu- tically made. If you like hunting tenant Wenstrom writes of fascina- weeks of practical study with Tele- the and outdoor sports, get a Zip -Zip plex you will be an expert operator. tions of amateur radio, both as a spare - shooter with plenty of pep and force. This amazing instrument teaches time hobby and as a service of immense If your dealer happens you right in your own home. Works value in times of disaster as well as in not to have them, or- like a phonograph. No knowledge of der from us. Zip -Zip needed -beginners learn at once! the more thrilling field communication shooter 31e or three for with explorers in all parts of the world. NOT A SCHOOL. Free 10 days' $1.00; send stamps, trial. Write for FREE booklet J -11. coin or money order. ryas Automatic Rubber Co., Columbia, S. C. TELEPLEX CO.. 72 Cortlandt Street, New York City

www.americanradiohistory.com 474 Science and Invention September, 1929 Hotter than Coal Television in Color and no dirt By Dr. Herbert E. Ives Tt OR DO away forever with the drud- InDeP t fiery of wood or coal. The most simple and economical invention (Continued front page 401) on the market is now giving perfect satisfaction to enthusiastic users everywhere. Burns 96% Air-4% Cheap Oil the scanned object, one bank diagonally to the thin glowing layer of gas and thus in- The Internatiónal Oil Burner fits in the the right, and another bank diagonally to creases its apparent brightness. Even so fire box of any range, stove or furnace. the left, so that the cells receive light it is necessary to operate these lamps from Installed in a few minutes. No noisy motor Or complicated parts. from both sides of the object and aboye. a special "I" tube amplifier to obtain cur- In placing the cells they are so distributed rents as high as 200 milliamperes. Costs Only a Few Dollars by color as to give no predominance in Reats just as well as a $400 or $500 oil burner without electricity or gas. Simply any direction to any color. In addition turn one Valve and you have all the heat large sheets of rough pressed glass are Standard Scanning Disc Used you want. Cleaner and better for heating set and cooking. Approved by National up some distance in front of the cell con- Underwriters' Laboratories and engineers THE receiving apparatus at present con- everywhere. Over 100,000 In use. tainers so that the light reflected from the object to the cells is well diffused. sists of one of the 16 -inch television 30 Days FREE Trial discs used in our earlier experimental work. Offer The television signals produced in the Behind it are the three special lamps and a Try this wonderful burner right in your own color sensitive photo- electric cells through home at our risk. Act quickly and get our lens system which focuses the light into a special low introductory price. Sold under the color filters are no different elec- small in absolute money -back guarantee. Write at aperture front of the disc. The Liumie en ou r once for free booklet on home heating and trically from those used in monochro- observer looking into this aperture receives, Radio Pn' rarafree burner offer. matic television. Three sets of amplifiers through each hole of the disc as it passes AGENTSS -our men are making big money intro- are required, one for each color, and three ducing International Oil Burners. The demand is enor- by, light from the three lamps-each con- mous. We want spare or full time workers immediately. communication channels in place of one, but trolled by its appropriate signal from the If $500 a month and more interests you, write or wire the communication channels are exactly us for our protected territory offer. sending end. When the intensities of the Clip This Coupon similar to those which were used with the three images are properly adjusted he INTERNATIONAL HEATING CO. same scanning disc before. 3808 Park Ave., St. Louis, Mo., Dept. .e-3 therefore sees an image in its true colors, Send your free booklet and free details on home beating For color television the three images and with the general appearance of a small for stove D furnace D. Also free burner offer. must be received in their appropriate Name colors, colored motion picture. Address and viewed simultaneously and in superpo- Satisfactory television in colors is a far aCheck if interested in making money as an Inter sition. The first problem was to find light snore difficult task than is monochromatic national representative With protected territory. sources which, like the neon lamp previ- television. Errors of quality which would ously used, would respond with the requisite pass unnoticed in an image of only one fidelity to the high -frequency signals of color may be fatal to true color reproduc- . television, and at the same time give red, tion where three such images are superim- High School green, and blue light. With such lamps posed and viewed simultaneously. In three - available a decision would have to be made color television any deviations from correct Course in as to how the three colors could best be tone rendering throw out the balance of the combined to form a single image. colors, so that while the three images might 2 Years Several methods of reception are possi- be adjusted to give certain colors properly, This simplified. complete High School ble. For displaying the transmitted image others would suffer from excess or defi- Course -speciallyprepared for home study to a large audience a grid* could be em- ciency of certain of the constituents. A by leading professors -meets all require- ployed similar to that used for the earlier ments for entrance to college, business. and further source of erroneous color exists at leading professions. ( demonstration but it would consist of three the scanning end. If the light from the a one. 20 Other Over 200 noted Engineers, Bus- parallel tubes instead of single object were not distributed equally to all CoursesInessMren,andEducatorshelped the cells, the object would appear as if Y prepare the special instruction Thus far the television images have been whichwhleh you need for success. No matter what received in a manner similar essentially to illuminated by lights of different colors your inclinations may be, you can't hope to succeed without epecialired training: Let our method for monochromatic television. shining on it from different directions. wgive sou the practical training Pounced. The surface of a disc similar to that used Color television constitutes a definite fur- ' American School at the sending end is viewed, and the light ther step in the solution of the many prob- D Dept A í1.668 Chicagoo from the receiving lamp is focused on the lems presented in the electrical communica- pupil of the observer's eye by suitable Money Back When You Finish If Not Satisfied lenses. To combine the light of the three SCANNING AMERICAN SCHOOL, Dept.H4$3 lamps, they are placed at some distance GREEN Drexel Avenue and 58th St., Chicago ARGON FILTER DISC Send me full Information on the subject chocked and behind the scanning disc and two semi- TUBES DIAPHRAGM how you will help me win success In that line. transparent mirrors are set up at right SEMI- TRANSPARENT ....Architect / ....Electrical Engineer angles to each other but each at 45° to the MIRRORS ....Building Contractor ....General Education ....Automobile Engineer ..__Lawyer line of sight. One lamp is then viewed ....Civil Engineer ....Mach. Shop Practice directly through both mirrors and one lamp ....Structural Engineer ....Mechanical Engineer R fl from each, as illus- \ÌÌ: LENS ....Business Manager ....Steam Engineer is seen by reflection ....C. P. A. & Auditor ..._Draftsman &Designer BLUE by the accompanying diagram. FILTER .___Bookkeeper ....High School Graduate trated HOLES The matter of suitable lamps to provide IN Name Age NEON *\ RED the red, green and blue light has required TUBE FILTER REVOLVING DISC St. and No a great deal of study. There is no diffi- Town State culty about the red light because the neon This diagram shows clearly how the three glow lamp which has been used previously light beams from the red, green and blue in television can be transformed into a suit- filters and their associated tubes are all Radio able red light by interposing a red filter. gathered together and viewed simultane- IR[EWholesale Catalog For the sources of green and blue light ously through a single hole in the scanning Set Builders -Dealers! Save Money! nothing nearly so efficient as the neon lamp disc at the receiver. There are 50 holes Send for the most complete book of nationally known Parts, Kits, Cabinets, Consoles, Speakers, Power Units, was available. The decision finally made in the whirling disc, but at any given in- Sets, etc. All at lowest wholesale prices. Quick service was to, use another one of the noble gases visible, in on all your needs. Write now, it le FREE- stant all three color beams are -argon -which has a very considerable their respective strengths. Lenses and a SHURE BROS. CO. number of emission lines in the blue and diaphragm help to make the image clearer. Dept. 323, Romberg Bldg. Madison and Market Su. CHICAGO, ILL. green region of the spectrum. Two argon lamps are employed, one with a blue' filter to transmit the blue lines and one with a tion of images. It is, however, obviously STOP TOBACCO green filter transparent to the green lines more expensive as well as more difficult Banish the craving for tobacco as of its spectrum. than the earlier monochromatic form, in- thousands have. Make yourself free and happy with Tobacco Redeemer. These argon lamps unfortunately are not volving extra communication channels as Notasubetitute, not habit forming. Write for free booklet telling of the nearly so bright as neon lamps and it was, well as additional apparatus. deadlyeffectof tobacco and the pos- to use various expedi- itive, easy way to remove therefore, necessary all craving in a few days. ents to increase their effective brilliancy. FREE high current den- Newell Pharmacal Co. BOOK Special lamps to work at of Dept. 884 Clayton, Mo. sities were constructed with long narrow and hollow cathodes so that streams of cold LATEST TELEVISION NEWS them. The cathode' is To be sure of getting your copy each month, water could cool appears every month in the columns of this viewed end -on. This greatly foreshortens magazine. If you have an efficient television subscribe to SCIENCE AND INVENTION, $2.50 of a year. Experimenter Publications, Inc., 381 receiver, send photos and description it to Fourth Avenue, New York City. a BELL RECORD, May, 1927, page 319. the Editor.

www.americanradiohistory.com September, 1929 Science and Invention 475 The Radio Robot By J. E. Smith LOOK AT THIS PHENOMENAL VALUE! (Continued from page 439) K O L S T E II using a pair of wires a condenser can be tested for leakage by impressing any volt- Electro Dynamic age from 0 to 200 volts direct current Reproducer across it and then noting the milliammeter Combined with 210 Power Amplifier and "B" Supply Unit I eading. Any kind of condenser, variable Gr fixed, may be tested for short circuits. This famous genuine Kolster K -5, AC Electro -Dynamic Reproducer is The complete with a 210 Power Amplifier and "B" Supply Unit all self - method of procedure is to plug tester contained on a steel frame. This real fine matched rugged Unit weighs cord into house lighting circuit and hook 45 lbs. without the Cabinet. The Cabinet itself is Pencil -Striped Walnut, the test wires on two binding posts after beautifully designed with Cathedral grille. inserting a vacuum tube in a socket and if If desired, the 210 Power Amplifier will also supply 22, 67 and 90 volts it shows filament emission, then open a "B" current, sufficient for any set using up to 8 tubes. An automatic volt- double pole double throw switch and bring age regulator tube, UX -874, maintains the "B" voltage silent and steady. the ends of the wires in contact with the This Electro- Dynamic Reproducer can be used with any battery or AC rotor and stator plates of the condenser. set, replacing the last audio stage, or be used with all tubes of the set. Wherever used it will bring out every shading and range of tone; every A reading on the milliammeter indicates note is reproduced with utmost faithfulness, pure and undistorted. It will a shirt-circuit ; absence of a reading sug- modernize any radio receiver. gests that the condenser is not a fit subject Uses 1 -UX -210, 2-UX -281 and 1 -UX -874 tubes. or patient for a radio hospital. A source A 20 -ft. cable is included with each instrument. Operates direct from cf alternating current voltage is also pro- 50 -60 cycle, 110 -120 volt AC current. vided for testing condensers ; there being Brand new in original factory cases and guaranteed. Every Reproducer is serial -numbered and high voltage and low voltage switches has factory guarantee tag enclosed. available for testing, as well as a shunt switch for the milliammeter when using direct current as rectified by a vacuum tube List Price $175.00 Never of any type. (without tubes) Q49.50 This test kit provides both direct current Before kivr and alternating current voltmeters. The AMERICAN SALES CO., 19 -21 Warren Street, New York City latter, with a range from 0 to 6 volts, may be employed for testing both a.c. and d.c. receiving sets. For instance, in testing transformers of a.c. receivers, connections are made to the two posts of the a.c. volt- meter and the condition of the secondary windings of the transformers is revealed. A BIGGER JO B - and you're the man Are Also, a test can be made you hunting a bigger job, or does the bigger LaSalle Problem Method. Let na Show you how to determine job hunt you? Why waste years learning through you can do just as well or better. The coupon whether the voltage of the filament wind- routine work, when you can acquire at home in a will bring you complete information. together ings is correct for the type of vacuum tube comparatively few months the specialized knowl- with details of our convenient payment plan; also employed. The same wires and same edge which brings promotion and salary increase? your free copy of a remarkable book -"Ten Years' set -up Thousands of men have increased their incomes Promotion in One." Make your start toward that may be used in diagnosing the troubles by home -study business training under the bigger job today. of loud- speakers, telephones, choke coils, Find Yourself Through LaSalle! and other types of coils. A milliammeter LASALLE EXTENSION UNIVERSITY, Dept. 9384R CHICAGO reading indicates that the circuit of the The World's Largest Business Training Institution Tell me about your salary- increasing pion for my advancement in the business field checked. Send also copy of coil under test is in satisfactory operating "Ten Years' Promotion in One," all without obligation. condition; at least, it gives proof that wire Business Management Industrial Management p Business English in the coil is not broken. Modern Salesmanship Banking and Finance Commercial Spanish Higher Accountancy o Modern Business Correapondence Effective Speaking ' In an attempt to confound the manifold Traffic Management Modern Foremanship Stenotypy- Stenography and almost uncanny performances of this Railway Station Management Personnel Management Telegraphy mechanical Law: Degree of LL.B. Expert Bookkeeping Credit and Collection and electrical trouble -shooter, Commercial Law C. P. A. Coaching Correspondence the writer inquired of the designer what provision had been made to test shielded Name grid vacuum tubes. Quick as a flash Mr. Present Position Stair offered a somewhat improvised meth- Address od and yet an effectual one. By use of .r, extra piece of wire, he pointed out, the four -element tube could be subjected to test by associating the two grid elements IntrOfferory and thus short -circuiting them. Then, Doaostur Electric search for "shorts" in the other tube ele- Now! Nickel Plating ments and after bringing the wire in con- ONLY Nickel, Brass, Make $150 $500 tact with the plate, if there is no light Copper, Silver, to a Week No experience required. $6.50 in the tiny automobile lamps on the test Gold, etc. Do YOUR OWN Electro- Plating in Your Rome. Plus Postage Garage, Office, or Place of Business. Electrically Deposit Metal- Nickel, board, the shielded grid tube is not short - Brass. Copper, Silver or Gold. You can Successfully do all the plating on circuited. In addition and your Automobile, Electric Fixtures, Faucets, Spoons, Forks. Chandeliers, Tools, Coffee to this test those Urns, Surgirai and Dental Instruments, Utensils large or small, Iron Stoves, Music Instru- already enumerated, there are three termi- ments; recondition scorn plating or plate New Work; do it Instantly without interrupting the Service or nals for testing batteries. without censoring the parts to be plated with the - This radio Robot can subject the entire ALADDIN PORTABLE ELECTRO- PLATER Simple and Economical to operate. Not a toy, but a practical Plating Outfit with which receiving set to the searching "eye" of a Perfect and Durable Work can be done. Positively Guaranteed to do as we claim. BE trouble -shooter, with a minimum disturb- YOUR OWN BOSS! Build up a Profitable Aladdin Electro- Plating Business of your Own. This offers wonderful ECONOMY to users and BIG MONEY-MAKING possibilities ance to the completeness of the set. The to AGENTS. Thousands in Service. Write for FREE Booklet and Testimonials and two voltmeters and one milliammeter, when 30 -Day Trial Offer Today. AGENTS and DEALERS WANTED EVERYWHERE Thousands in Service since 1924 P. J. F. BATENBURG, Dept. 110, RACINE, WISC. applied independently, determine the volt - ages of A, B and C batteries. A flexible five -wire lead and plug with adapters to fit all radio sets is easily plugged successively Real into each socket of the radio set. The A Gas Engine Flies battery, its lead wires, and the rheostat of Life's Secrets! Model Airplane 1 Mile Amazing new book, "Safe Counsel ! one vacuum tube are examined and their .7 you At last A ,practical engine know etiaight rom[ the Shoulder Gives ad- condition revealed at a single reading. Sim- vice to newly married. Explains anatomy f (not an experiment) has been reproductive organs, Impotence, laws of -Sex ilarly, by use of the direct current volt- Life. mistake. to avoid, diseases. pregnancy. perfected to fly model airplanes. etc. Containe 9 startling sections: 1-Science meter, the conditions of the B battery or Eugenics, 2 -Love, 8- marriage, 4- Child- Develops % h. p. Will also run b'irth, 6- Family Life. 6- Sexual Science, 7- I-i eliminator unit and the primary winding Diseases and Disorder., 8-H eel t h and small rowboat or light motor Hygiene. 9-Story f Life. In all. 104 chap - and the loud- speaker are checked at one 77 cycle. - at risk. Máúdinup:toewr'aExamine reading. And, finally, the milliammeter at onceo f or FREE il- causes to pass in review the condition of Send No Money FREESendlustrated Bulletin No. 46. Write for your copy today. Don't send s the grid biasing battery as well as the cent. Pay postman only 51.98, plus postage. 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www.americanradiohistory.com 476 Science and Invention September, 1929 BOOK REVIEW A Test Every Bladder ASPECTS OF SCIENCE, Second Series, The author of the present work is a Pro- by J. W. N. Sullivan. Stiff cloth covers, fessor and former Director of Physics at Mc- Sufferer Should Make 5" x 71/2", 205 pages. Published by Al- Gill University, in Montreal, and some time Medical authorities agree that 65% of fred A. Knopf, New York City. Price ago wrote a book concerning ice formation. all men past middle age (many much $2.50. The volume reviewed here deals with the rapid made in the science younger) are afflicted with a disorder of Fifteen essays incorporated in this volume advance which has been ice The structure and forma- the prostate gland. Aches in feet, legs cover a wide field, such as is indicated by the of engineering. tion of various kinds of ice are covered, to- and back, frequent nightly risings, sciatic : On Being Oneself, On Pri- following titles ice navigation and pains, are some of the signs -and now a vate Universes, Relativity Theory, Structure gether with chapters upon A has also been devoted well -known American Scientist has writ- of the Atom, The Materialist Creed, The Sci- expansion. section use of steam, ther- ten a remarkably interesting Free Book ence of Everything, which are among some of to ice remedial work with calcium chloride, and oth,or that tells of other symptoms and just what the chapter headings. The main theme illus- mite, hot water, be used in controlling they mean. No longer should a man ap- trated in these essays is that science depends chemicals which may book is written primarily proaching or past the prime of life be not only upon the nature of the external world winter floods. The in immediate work of content to regard these pains and condi- but also upon the constitution of the human for those engaged the and undoubtedly will not be of tions as inevitable signs of approaching mind. -P. L. W. ice engineering age. Already more than 50,000 men have interest to the layman, as it is quite mathe- used the amazing method described in this matical in its treatment. Engineers, however, book to restore their health and vigor - AND MISLEAD- will find much. of interest and assistance in SCIENCE: LEADING their problems in this text. L. W. and to restore the prostate gland to its ING, by Arthur Lynch. Stiff cloth cov- solving -P. proper functioning. Send immediately for ers, 5" x 71/2", 376 pages. Published by mail your this book. If you will request Dutton & Co., New York City. 4521 E. P. to The Electro Thermal Company, Price $3.00. Morris Avenue, Steubenville, Ohio-the THE STARS AND THE is great and the true scientist is one THE SUN, concern that is distributing this book for Science by W. W. Smart. Stiff who always searches for the truth and holds UNIVERSE, the author will be sent to you abso- 51/2" x8 ", 288 pages, illus- -it this paramount above all things. Despite our cloth covers, / lutely free, without obligation. Simply Published by Longmans, Green & schools and universities, the' average man is trated. send name and address. But don't delay Co., New York City. Price $5.00. for the edition of this book is limited. prone to accept a false interpretation of science, which in many cases may have been This book presents a historical review, to- If you live West of the Rockies, mail your inquiry to gether with an account of recent astronomical The Electro Thermal Co. partly due to the scientists themselves. The 363 Van Nuys Building, Dept. 41X author examines physics, chemistry, biology, discoveries, the constitution of the heavenly LOS ANGELES, CALIF. mathematics, physiology, psychology, relativity bodies, and the modern view concerning their and psychoanalysis, together with other sub- characteristics. It has been written for the jects and exposes the untruths in them which general public interested in science, and there- Start to llay" fore, the use of technical language has been have been accepted as fact by the general and illustrated with line Day too gullible public. Popular misconceptions avoided. The text is well Very First drawings and photographs and has been ar- Be the life of the party. Xylor- are upset and we are told that many things are imbists make $5 to $55 a night. not true, simply because tradition tells us that ranged in a systematic manner. Fundamental No knowledge of music required. concisely and a Wonderful for home. Free, easy they are. -P. L. W. concepts have been treated lessons; five days' trial; a year to chapter is devoted to stellar evolution. The p Send Coupon for first seven chapters deal with the sun, planets BIG FREE BOOK! ICE ENGINEERING, by Howard T. and comets, and the others with the movement J. C. Deegan. Inc.. Dept. 1566 -A. 1770 Berteso Ave., Chicago Barnes, F.R.S. Stiff cloth covers, of stars, their distances, light characteristics. Send me, without obligation, full details of Free Trial offer double stars, star clusters, the origin of the and easy -payment plan on the Deegan Xylorimba. 6" x 91/4", 364 pages, illustrated. Pub- lished by the Renouf Publishing Co., planetary and stellar systems and the structure Name of the universe. Address Montreal, Canada. Price $5.00

INDEX TO ADVERTISERS

PAGE PAGE PAGE PAGE P A E L 454 Page -Davis School of Adver- Thermal Co., The 476 Lacey & Lacey Adams, John T. 461 Electro Lancaster & Allwine 454 tising 468 Allied Radio Corporation 391 Evans & Co., Victor J. 455 Landon School, The 459 Pan -American Band Instru- American Sales Co. 475 Excello Products Corp. 456 LaSalle Extension Univer- ment & Case Co: 466 American School, The 385 -474 sity 450 -475 Paris -American Pharmacal Co 465 American School of Photog- Liederman, Earle E 469 Piccadilly Hotel 469 raphy 469 F Lincoln Airplane School 473 Plymouth Rock Squab Co 457 American Telephone & Tele- Lyons Mfg. Co., The 468 Polachek, Z. H. 454 graph Co. 451 First Hawaiian Conservatory Publishers' Classified Service 973 Anita Institute 464 of Music, Inc. 446 Audel & Co., Theo., Fisher Mfg. Co., Adam 454 Mc R Inside Back Cover Franklin Institute 463 Radio Institute of America 445 Automatic Rubber Co. 473 Franklin Publishing Co 475 McCarrie School of Mechanical Radio Training Ass'n of Dentistry 450 America 393 Ralco Supply Co. 460 B Randolph & Co. 452 H M Red Bug Boy 463 Batenburg, P. J. F. 475 Bean, L. L. 460 Ilawk Model Aeroplane Co..... 454 Mead Cycle Co. 460 S Benedict, Paul A. 468 High School Home Study Meyer Both Co. 470 Bernard & Heller 452 Bureau Back Cover Midwest Radio Corp'n 457 School of Engineering of Mil- Bliss Electrical School 472 Hobart Bros. Co. 454 -470 Miller, Carl 452 waukee - 465 Bureau of Inventive Science 454 Munn & Co. 452 See Jay Battery Co 464 Shure Bros. Co Southern Products o 469 C N Strongfort Institute 467 Ideal Aeroplane &' Supply Co., Studebaker Corporation of 449 Chicago Sign Sales Co. 460 - Inc. 464 National Automotive & Elec- America, The Coleman, Watson E. 452 Inkograph Co. 460 trical School 451 -456 Studebaker Watch Co. 472 Conn, Ltd., C. G. 468 International Correspondence National Radio Institute 389 Coyne Electrical School 387 Schools 446 - 464 -966 National School of Visual Edu- T Critchlow, Walter,.. International Heating Co. 474 cation 477 Inside Front Cover Newell Pharmacal Co 474 Tamblyn, F. W. 468 477 457 Tarbell Systems, Inc. 471 Crusader Apparatus Co. New England Mills Co 473 J New Method Mfg. Co 450 -459 Teleplex Co. N. Y. Electrical School, The.. 459 Townsend Labs. 456 D Johnson Smith & Co. 469 N. Y. Institute of Photography 472 Jones Motrola Sales Co. 470 Norton Institute 459 U Deagan, Inc., J. C. 470 -476 U. S. Model Aircraft Co 472 Detroit School of Lettering.... 459 Universal Plumbing School 457 Dobe, Fred'k 461 K o Douglas, Lyle 468 W J. A. 450 Kelsey Co., The 457 O'Brien, Clarence A. 453 Dryer, Prof. 480 Dynamic Mfg. Co. 475 Kriss -Kross Corp'n .447 Ozment, C. J 469 Whirlwind Mfg. Co.

www.americanradiohistory.com September, 1929 Science and Invention 477 Dr. Worden's $600,000 Hobby By Alfred M. Caddell Save00 (Continued from pape 397) with this eighty -two separate stamps, fifteen pair tremendous proportions is further attested OFFER.' and three joined in a strip. Their total by the fact that the Government in Wash- Send no value is over $2,500. ington conducts a special office where the niotlel A five -cent stamp, with head of Thomas first run of stamps may be purchased by Jefferson, was issued in 1851. Like its pre- collectors. This office alone, at current decessors it had edges not perforated and stamp prices, does an annual business of therefore the stamps, turned out originally nearly $500,000 a year. These issues may in sheets of 100, had to be separated by subsequently have a greatly enhanced value. cutting. The 1851 stamp was brown. There Dr. Worden keeps his valuable stamp are twenty -nine of them in Dr. Worden's collection in a huge fireproof vault, in Gà*rong collection, five unused, twenty -four used, which are also housed other records of in- ITH four pair and three strips of three. An- calculable worth. For his business is the other Jefferson stamp in brown, issued in assembling, indexing and furnishing of very These 1856, is the first of the stamps with per- valuable chemical information to any and forated edges. There are twelve of these all who may wish to purchase it. In this Muscle Builders unused and sixty -seven used possessed by vault, adjacent to his library, is all the Dr. Worden. The seventy -nine stamps knowledge of the world pertaining to cellu- which he owns of these two issues-1851 lose chemistry, which knowledge he sells to llfori5e patent attorneys and in- and 1856- represent a value of $5,000. industrial concerns, Why pay an extravagant price to turn page ventors anxious to safeguard their ideas by for strength -get all equipment As Dr. Worden continued you require and excellent course rare stamps of a by- patents. He has a copy of every chemical for only $5.00. after page of costly, of instructions super -man. he came to a page bearing three patent issued in the United States and for- Develop muscles of a gone age, in- Get strong and amaze friends. We stamps which are decidedly rare. Close in- eign countries, each of which patents is show how to easily master feats and cross -indexed, one patent alone which now seem difficult -if you spection showed that the picture in the dexed want physical culture for your health'. by 3,015 index cards, so in- rake, th', muismret hat you center of each stamp was printed upside- being covered need. save t teast tarthall. We turnieh a ten cable achest expander volved are its ramifications. Besides, in o detobinew,of down. That was the first time this error ee. u strength, eDringY rubber oto his he has more than 20,000 scien- live, extra 'e u on the part of the Government Printing library, e long a a d giv< ro7mtanee B1,0 eor xpai eat developmenr. 1'or tific books, each of which has been ab- hand gripe for Office ever occurred and such stamps are aim evget pair of patrip pin wertnl grip and forearms. and the information therein placed which eagerly sought by collectors. These stamps stracted We include ue e sine parts all, he has more than 6,000,000 permits you to develo 'youc back, - were issued in 1869. One, a fifteen -cent on cards. In nd legs -a al cPe ece ity. allied scientific references, a d leg firer jet. stamp, unused, is worth $5,000 ; a second, chemical and their legs. Develop lee will give seventeen years. which we furnish.fdureo' will ¢ a twenty- four -cent, used, has a value of the work of about you that And this man started on less than the yiln your zwi.ndIn° addition de a $600, and the third, a thirty-cent stamp, is e0eoraily written course which 'nccontains and diagrams ehowin¢ bow to proverbial shoestring. Born in Ypsilanti, pictures you worth $2,000. develop a Y part.a your body..o quickly get f ex in 1875, his father died when he agi "Of course, a famous stamp has a his- Michigan, gain Orel test advantage from their cod was less than a year old, leaving nothing Act now tory," said the doctor, "just as a famous SEND NO MONEY they i diamond may have. There is the interest- to his widow and child. Somehow, All item pictured included ' ,Oecial Ver. Sign name d to attend t} n ing British Guinea, 1 cent, 1856. To the existed and the boy managed addressádre. to pon and rn ñ to e rend your ten cable cheat de- means nothing, school and earn enough money to keep the veloper, wall parte, e pair of hand ordinary mortal this phrase e asp t home together. Later, he shot sparrows to a pur[man but to the stamp collector it is the acme 5Y' ntu cents each of- $5.w. Aloe ct ge arrive? of ambition. It is an octagonal bit of paper obtain the bounty of three (If send county, and with this money rder in advance. we Puy preage.) comprising about one square inch. On it fered by the - GUARANTEE and a few $35.04 -paid his first year's tuition at the All Crusader product, are guar- are engraved a full -rigged ship foci to give mire Batir Latin and English words, almost obliterated Michigan School of Pharmacy at Ann faction pr mopes back. now by time and the cancellation mark. Arbor, riding a bicycle ten miles there it was red, but now it is worn and and ten miles back every day. And on the Crusader Apparatus Co., Once N. J. faded to anaemic cream. It would be hard way to and fro, over the actual road made Dept. 409, 44 Parker Ave., Maplewood, to imagine a more insignificant appearing famous by Will Carleton in his poem "Over I accept your offer. Send me everything described he used to in your advertisement by return mail. I will pay hit of paper. And yet it sold for $32,500 the Hill to the Poorhouse," postman $5.00 plus postage on arrival. It is under- 1 price look at that same poorhouse as he pedaled stood if I am not entirely satisfied after examination. at a Paris auction in 1922, the highest I can return the goods and you will refund my money. to date ever paid for a stamp. It gains by, and wondered if he would ever be able fact that it is to pedal through life sufficiently strong to its great value from the Name the only one of its kind in existence. Arthur escape riding within its gates ! Utica, N. Y., one of America's Hind, of Street leading collectors, paid that price for it. of Great Britain, who is "King George State an enthusiastic collector, had an agent at City that sale and bid $31,500 for this famous $5,000 FOR PERPETUAL I- _J stamp. Mr. Hind secured it by paying a thousand dollars more than the King of- MOTION fered. But the American did not know at he was bidding against the The editors have received thousands of the time that motion de- Mr. Hind was a guest at a different designs of perpetual I in King. Later, of dr- BIG PAY JOBS in Buckingham Palace. There, vices, and have received hundreds reception letters soliciting finances for the in conversation with the King, he expressed cular regret that he had bought the famous stamp building of perpetual motion machines. ELECTRICITY his host, and offered if receive Amazing new method Trains in competition with The editors know that they $6000 you quicker and better. Motion the stamp as a present to the King, but these letters, there are thousands of others Pictures in your own home make every point clear. Genu- the latter replied that he could not think of in this country who get similar letters ine DeVry motion picture pro- his guest of so rare a possession. made in the to jector at no extra cost. Thou - depriving and who fall for the claims sands of feet of film furnished. "Many stamp collectors specialize in numerous prospectuses giving the earning $15022 We pledge to give you training show errors in and employment service nec- freak stamps -those that capacities of the various machines.. essary to secure a better job at design or printing. It would seem that bigger pay or refund money. would be lim- Most of the shares of stock for these WEExLI Get full facts. No obligation. the scope of such collections Write quick while offer lasts. ited, yet hardly a year passes that some perpetual motion machines are being sold country does not blunder in one of its at a rate of $1.00 per share, although some "I*4 issues. inventors are trying to sell shares of Motion Pictures Dr. Worden's collection of stamps is stock at $100.00 per share. i Train You QVIfK° mounted in eighteen large volumes, bound made to order Therefore, the editors of this publica- National School of Visual Education. Dept. 9 -N in Morocco, and the books, come in and show us- 537 S. Dearborn St., Chicago, III. contents, about tion say, "Just cost alone, without their SHOW us working model of a Send book, "The Film Way to Bigger Pay." with is nothing merely -a facts about this new, easier way to master electricity. $1,100. But $1,100 practically perpetual motion machine and we will compared with the value of the stamps. Name Age was issued give you $5,000.00. But the machine must The first stamp, it developed, by tides, winds, St. or R. F. D 4 and is known as not be made to operate in 1840 in Great Britain, natural evaporation or hu- City in honor of the person of waterpower, the Mulready, midity. It must be perpetual motion." State that name, who was a member of the Royal Academy of Science. That the business, MAIL THIS COUPON NOW! which is a hobby for some, has grown to

www.americanradiohistory.com 478 Science and Invention September, 1929,

OPPORTUNITY AD-LETS OU will find many remarkable opportunities and real bargains in these columns. It will pay you I. made to read and investigate the offerings every month by reliable firms, dealers and amateurs from all over the country. No matter what you may be seeking, whether supplies, automobile accessories, the opportunity to make money, or anything else, you will find listed here of the month. the best and most attractive specials Advertisements in this section fifteen cents a word for each insertion. Name and address must be included at the above rate. Cash should accompany all classified advertisements unless placed by an accredited advertising agency. accepted. No advertisement for less than 10 words Objectionable or misleading advertisements not accepted. Advertisements for the November issue must reach us not later than September 1st. EXPERIMENTER PUBLICATIONS, INC., 381 Fourth Avenue, New York, N. Y.

Advertising Agents Wanted (Continued) f Business Opportunities (Continued)

Get into Advertising. Learn quickly at homo. Experi- ence unnecessary. New, easy plan. No text -books used. Make your own products. Employ agents yourself. Artists and Art Students are printing 250 signs and Practical work. Old established school. Send name and Toilet articles, soap, extracts. We furnish everything. pictures an hour without machinery. Sample and par- for Valuable boor Free. National Scientific Laboratories, ticulars 10e. address interesting free booklet. Page -Davis School 1975 Straco -1015 Mulberry, Springfield, Ohio. of Advertising, Dept. 533 -A, 3601 Michigan, Chicago. W. Broad, Richmond, Va.

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$60 -$200 a week. Genuine Gold Letters for store win- Two new Patent Auto Accessories, exclusive territory, Caneras and Photography Supplies dows. Easily applied. Free samples. Liberal offer to no competition. Wholesale and Retail Sales, Satisfac- general agents. Metallic Letter Co., 441 B., North Clark, tion guaranteed, samples 50e. Desk 8, Ball ,Maisufac- Chicago. taring, 9441 Pleasant, Chicago. Make money in Photography. Learn quickly at home. Spare or full time. New Plan. Nothing like it. Ex- perience unnecessary. American School of Photography. Big Money applying Gold Initials on Automobiles. Strange new electric iron cord! Prevents scorching. Dept. 5332, 3601 Michigan Avenue, Chicago. Easiest thing today. No experience needed. $1.45 profit Saves electricity. Cannot kink or snarl. Used on tele- every $1.50 job. FREE SAMPLES.. "RALCO," 81043 phones also. $25 daily. Samples Free. Neverknot, Dept. Washington, Boston, Mass. 9 -K, 4503, Ravenswood, Chicago. Chemistry 510 daily silvering mirrors, plating and refinishing lamps, reflectors, autos, beds, chandeliers by new method. Airplanes- Aviation Outfits furnished. Write Gunmetal Co., Ave. D, De- catur, I11. Your Chemical problems solved and working process furnished for Fine Dollars. Write me. W. Stedman Richards, Box Simplex Air Model Co. Auburn, Mass. Send 5e for Consulting Chemist, 2402, Boston, Mass. $50.00 Weekly. Men wanted to demonstrate and take supply catalog. ten orders daily direct from motorists. Amazing Magnetic Trouble Light. Sticks anywhere! More orders, bigger pay. Write for demonstrator and particulars. Magno, Attention Chemical Experimenters! 100 chemicals con- Beacon Bldg., 49, Dept. -C, Boston, Mass. Biggest, sisting of complete selection for the experimenter's labora- Best Catalog Model Airplanes. Parts, Supplies; tory. Chemicals of highest 5e postpaid. Ideal Company, 23 West 18th Street, New quality obtainable sufficient York. quantities for hundreds of experiments. Apparatus with this outfit to perform many experiments. Really ideal for Agents-I'll pay you.$19 daily to wear fine Felt Hats any laboratory. Price $4.00. 50 pieces high grade chemi- and shoe them to friends. Smartest styles. Latest shades. cal apparatus containing most essential equipment for .$$5 laboratory. Worth $2 to saving on every hat. Samples Free. Write 2c Postage Stamp brings you complete Model Airplane three times price asked. Our price Taylor Hats, Dept. MC -170, Cincinnati, Ohio. Supplies Price List. $7.00. Postage prepaid. Send money order or C. O. D. A. A. C. Model Aircrafters; 340 to l'inca Chemical Co., 1524 St. Marks Ave., Brooklyn, East 188th Street, New York. New York.

Succeed With Your Own Products. Make them yourself. Formulas, Processes, Trade -Secrets. All lines. Catalog. Industrial Chemist furnishes and develops formulas, Circulars free. D. Thaxly CO., Washington, D. C. Books processes; all lines. Moderate charges. Inquiries invited. Lex Clore, Industrial Chemist, Crawfordsville, Ind.

You Are Wanted to resilver mirrors at home. Immense profits plating autoparts, tableware, etc. Write Sprinkle, Three Big Wild West Novels in magazine form -all for Plater, 955, Marion. Indiana. 50c- titles are "Gold," by'. Charles Snow; "Hell on Correspondence Wheels," by John Breck, and "The Border Wolf," by Courses 'Robert Anses Bennett -all illustrated-all individually bound novels. Send 10e for them to Mackinnon -Fly Publications, Inc., 381 Fourth Avenue, New York, N. Y. Big Ohio Corporation wants county manager. Oppor- tunity $50 to $75 weekly. Earnings start immediately. Used correspondence school courses sold on repurchase Good for $5,000 yearly. We furnish everything, deliver basis. Also rented and exchanged. Money-back guarantee. Catalog free. (Courses bought). Lee Mountain. and collect. Capital or experience unnecessary. Fyr- Five Popular Detective Fyter Co., 1906 Fyr-Fyter Novels in magazine form - Pisgah, Alabama. Bldg., Dayton, Ohio. written by famous authors of mystery fiction-titles are- "Star of Death," by R. T. M. Scott; "The Secret De- fenders," by Anne MaeMahoa; "Stealthy Terror," by John Ferguson; "The Taxi Slander," by J. L. Byrne, Big Money Weekly. Newest window letters out. and "The Marsh Slander," by N. B. Mavity -all five for a Easiest to put on. No experience needed. Free samples. single $1. Write to Madrinnon -Fly Publications, Inc., Detectives " Raleo," 5 -1043 Washington, Boston, Mass. 381 Iourth Avenue, New York, N. Y.

$2.45- Raincoats Detectives. Work home or travel. Experience un- all Colors. Trenchcoats, Tweeds, Beauty Secrets worth hundreds of dollars-nose yours necessary, Particulars free. Write George Wagner, 2190 Alligators, Leatherettes. Sample Coat and bonus to for only 50e. A complete Encyclopedia of the art im- Broadway, N. Y. workers. Beautiful Outfit Free. Bradley, Dept. AD -9, proves your beauty and personality by that famous Beauty 230 S. Wells, Chicago. Culturist, Eva Nagel Wolf. Large 9" by 12" book, with dozens of illustrations and over a hundred pages of helpful, invaluable advice. Send 50e to Experimenter Pub- lications, Inc., Nery York, N. Y. Sell High Life Cigars. Big money made. Write for For Inventors information. John S. Davey & Co., Stop 25, Schenectady Itoacs, Albany, N. Y.

Business Opportunities National Distributor with tremendous sales organization desires to add another article of merit on exclusive Gold Leaf Window Letters and Script Signs; no ex- basis; patented preferred; must be household or office ap- perience; 500% profit; samples free. Consolidated, 69 -R, pliance that will retail around $1. Write only full de- West Van Buren, Chicago. tails; send sample; references exchanged. E. H. Bauerle, Sell By Maill- Books, Novelties. Bargains.! Large 80 Boylston Street, Boston, Mass. - .... Profits! Particulars FREE! b. Elfco, 525. South Dear- born, Chicago. Carter Window Washer. Exclusive Distributor wanted. Big profits. Cleans, Dries, Polishes, one operation. Unpatented Ideas Can Be Sold. I tell you how and Territory closing fast. Art quick. Carter Products, help yea make the sale. Free particulars (Copyrighted). 9701/2 Front Street, Cleveland, Ohio. Make big profits, Chinchilla Rabbits. Guaranteed Write W. T. Greene, 908 Barrister Bldg., Washington, plan returns your investment. Real money makers. It. D. C. Mueller, U. S. National Bank, Denver, Colorado.

$12.00 Daily Showing New Tablecloth. Looks like Linen. Inventors. Use our special service for presenting your Wash like oilcloth. No laundering. Sample free. Best - Free Book. Start little mail order business. Hadwil, ever, 651 Irving Park Station, Chicago. invention or patent to manufacturers. Adam Fisher Mfg.. 5A -74 Cortlandt Street, New York. Co., 205 -A Enright, St. Dallis, 11e. ..

www.americanradiohistory.com September, 1929 Science and Invention 479

Formulas Miscellaneous (Continued) Patents Wanted

Artificial lee- Making formula (without machinery), Any possible help for anything Scientific. References, Inventions Commercialized. Patented or unpatented. 25c. Money -making proposition, stamp. Ten guaranteed etc. Least expense. Obvious. Investigate. F. Jones, Write, Adam Fisher Mfg. Co., 205 Enright, St. Louis, Mo. original formulas 25e. Neil Tasker, Shamokin, Penna. 426, G. P. 0., New Ycrk.

Free Formula Catalog. For agents. Pitchmens, Houdini Debunks Spiritualism. The master magician Western Chemical, Salem, Oregon. now describes hove the spiritualist fools the public -all Photoplays Wanted in this big, well illustrated book. Size 9" by 12" -112 pages. Book complete, only 50e. Send for it today to Experimenter Publications, Inc., 381 Fourth Avenue. New York, N. Y. $ $ $ For Photoplay Plots, Stories accepted any form, re- Help Wanted -Instruction vised. criticised, copyrighted, marketed. Estab. 1917. Booklet free. Universal Scenario Co., 223 Western & Santa Smatter Pop -the famous comic strip artist now brings Monica Bldg., Hollywood, Calif. you 50 comic strips all nicely hound in a colorful book. Wanted Immediately, Men -Women, 1S -55, qualify for Price only 25e. Write Experimenter Publications, Inc., steady Government Jobs; $125 -$250 month. Paid vaca- 381 Fourth Avenue, New York. N. Y. tions, common education. Thousands needed. Write, In- struction Bureau, 293, St. Louis, Mo. Printing Outfits and Supplies Oi Oi t I'm Letting. The Jewish Joke Book that keeps then laughing. Plenty of wise- cracks and plenty of f un- only 25e complete. Write Experimenter Publications, Inc., 381 Fourth Avenue, New York, N. Y. Instructions Print Your Own cards, stationery, circulars, advertising, etc. Junior press, $5.90; job presses, $11; rotary, $149. Print for others; big profit. Easy rules furnished. Write for catalog presses, type, paper, etc. Belsey Company, Men -Women, 18 up. G. S. Government Life Jobs. 24 Famous Screen Stars in Scenes of Passionate Em- Q -6, Meriden, Conn. $105.00 to $280.00 month. Steady work. Paid vacations. brace. It's a series of snappy lessons in how to make Common education usually sufficient. , Valuable book love. Poses by Greta Garbo, John Gilbert, Billie Dove, with list positions, sample coaching and full particulars Nils Asther, Douglas Fairbanks, Jr., Lupe Velez and Free. Write immediately. Today sure. Franklin In-- others equally famous. All Free with a one year substitute, Dept. A -4, Rochester, N. Y. scription to Screen Rook, the magazine that publishes a complete novel of the best movie of the month. Send Radio only $2.50 to Mackinnon -Fly Publications, Inc., 381 Fourth Avenue, New York, N. Y. Mail Carriers -Postoffice Clerks. $1700 -$2300 year. Steady work. Men 18 -45. Frequent examinations. Com- mon education. Particulars free. Write immediately. Get Commander Byrd's messages from the Antarctic Franklin Institute, Dept. A -15, Rochester, N. Y. with a Short Wave Radio Set. Complete Short Wave- Manual with instructions for building and full size blue Patents prints -all for 50e. Write today to Experimenter Pub- lications, Inc., 381 Fourth Avenue, New York, N. Y. Inventions

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www.americanradiohistory.com / 480 Science and Invention September, 1929 Over the Mountains from Los Ânfe1es - -- 5591esori

, Gallons of GAS

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