Modern Mechanix, July 1937

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EXPOSING STAMP COUNTERFEITERS NS © ——— ser miin NA namn aaki, Ii Wrenn TNS WT ee IA Ad heed PSSA a i ea NAN SASS my tiene tenga UW slaty pase NRA i PANN erties Sa ae one NAS a HOME-MADE LIGHTNING—SEE PAGE 94

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[aa was heavy that blistering hot Summer afternoon as Mr. E. P. Keenan of Chicago, returning from a business trip, sped along Waukegan Road. His passenger did most of the talking. Mr. Keenan was too busy keeping one eye glued on the oncoming traffic in the other lane. “We're making pretty good time,” Keenan’s pal said. He couldn’t reach “Home Sweet Home” quickly enough. A Close Shave Bang! Like a thunderbolt the stac- cato crack of a blow-out rose above the roar of the motor. In despera- tion he gave the steering wheel one final, frenzied tug. The car bolted—lurched to the right—and came to a stop at the brink of a deep ditch. They were safe — yes. But after that close call no wonder Mr. E. P. Keenan will tell you that he now “believes in miracles.” It took Goodrich engineers to fight this driving hazard for Ameri- can motorists and provide them with a real defense against high- speed blow-outs. They invented HE WAS HEADING FOR | HOME SWEET HOME’WHEN -BANG!A BLOW-OUT! @ eased Read TED HU SING’S eee terror- the now famous Life-Saver Golden Ply which is found only in Good- rich Silvertown Tires. This remark- able Golden Ply is a layer of special rubber and full-floating cords, scientifically treated to resist in- ternal tire heat. By resisting this heat, I am told, the Golden Ply keeps rubber and fabric from sepa- rating—keeps blisters from form- ing. Thus the blow-out that might have been, never gets a start. Are Your Tires Safe? You can bet your bottom dollar that Mr. E. P. Keenan of Chicago, is now riding on Silvertowns. My advice to every motorist who has his own and his family’s safety at heart is to see these life-saving tires at any Goodrich Silvertown Store or Goodrich Dealer’s. The sooner the safer. crowded moments experienced by a Chicago motorist. 2 ; E ofthe. SKY l Millions have joined the FREE Silvertown Safety League ë —-pledged to drive safely. See your Goodrich dealer and join now. Nothing to puy. He’ll get for you FREE a handsome emblem with red crystal reflector to protect you if your tail light fails. oodrich SAFElY Silvertown With Life-Saver Goiden Ply Blow-Out Protection

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IT jumped trom 98 a week to s0 ~~ @ tree Book started me toward this GOOD PAY IN RADI I had an $18 a week job in a shoe fac- tory. I'd probabiy be at it today if I hadn’t read about the opportunities in nanio, and started training at home for em. by S. J. E. (NAME AND ADDRESS SENT UPON REQUEST) ‘The training National Radio Institute gave me was so practical I was soon ready®to make $5, $10, $15 a week in spare time servicing Radio sets.’’ H sanas TELE] Zon “N.R.I. Training took me out of a low- pay shoe factory job and put me into Radio at good pay. Radio is growing fast. The field is wide open to properly “When | finished training | accepted a Job aS serviceman with a Radio store, In three weeks I was made service man- ager at more than twice what } earned in the shoe factory.” ‘Eight months later N.R.I. Employment Department sent me to Station KWCR as a Radio operator. Now I am Radio En- gineer at Station WSUI. I am also con- nected with Television Station W9XK.”’’ trained men.’ how I Train You at Home BE A RADIO EXPERT Many Make I trained have good jobs in these Find Out What Radio Offers You ; branches of Radio. mar Soe canes now for ene Rewards in H io. 's free to any fellow over 16 years J. E. SMITH 38 0 $50 $7 $ Many Make $5, $1 0, $15 a Week Extra old. It points out Radio’s spare time and full "President, ` 9 9 . i time opportunities, also those coming in Tele- National Radio in Spare Time While Learning vision; tells about my Training in Radio and Institute A Week ; Television; shows you 131 letters from men Established 1914 The day you enroll I start sending you Extra I trained, shows what they are doing, earn- Money Joh Sheets. They show you how to do ing Zy aoe hee. Do you too want a better job? Do you Radio papeis jobs; how to. cash in quickly. ment ‘MAN, CO. too want to make more money? Radio shroughout your training I send plans and PON in an envelope. a‘ . d full +i ideas that made good spare time money—from or paste on penny offers many spare time and full time $200 to $500 a year—for hundreds of fellows. Post: card—NOW! opportunities: for good pay. I peer, epos al Radio equipment, give you Ja a mr Prosi: ‘ practica adio experience—show you how to ent, ept. . , Get Ready Now For Jobs Like These conduct experiments, build circuits illustrat- National Radio In- ing important Radio principles. oi b C. ee RICH REWARDS Broadcasting stations employ engincers, IN RADIO operators, station managers and pay up G Ec EE ES DE Aas ES A N R E M D S DE A ON E A R O S L E a A A a to $5,000 a year. Spare time Radio set | servicing pays many $200 to $500 a E J. E. Smith, President, Dept. 7-GH, A year— full time servicing jobs pay many 3 National Radio Institute, Washington, D. C. z $30, $50, $75 a a sg Many Rago pa B Dear Mr. Smith: Without obligating me, send ‘‘Rich Rewards E peris are operating x HA ROSE ee B in Radio,’’ which points out spare time and full time opportu- m Radio businesses. Radio manufacturers @ nities in Radio, and explains your practical method of training a and jobbers employ testers, inspectors, g at home in spare time to become a Radio Expert. (Please vvite plainly. } B foremen, engineers, servicemen, paying a E up to $6,000 a year. Radio operators on E E a A R A O EAA A TREER OR merge AS reuse N i ships get good pay, see the world. Auto- mi i mobile, police, aviation, commercial A ET E E T A E perro wo eeu aa’ wa way ee x heres we Roeser en ees co Fi Radio, loud speaker systems, offer good a $ g opportunities now and for the future. a City ENAA Dh AEE Pardes ia D E O LOA Ta ENANA a7 MONNIK ACE Ka BRENNE BUA aa sma sa 5 Television promises good jobs soon. Men A AE MT A RO OW CB When Answering Advertisements Please Mention July Modern Mechanix 3

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JULY 15 CENTS Volume XVIII SAME PRICE Number 3 IN CANADA Circulation over 250,000 Copyright 1937 by Modern Mechanix Publishing Co. NEXT MONTH SPECIAL FEATURES inaa Backyard Railroad - - - ~- + = 30 30 Exposing The Stamp Counterfeiters By James N. Miller Fireworks For Festivals - - * s % 4.2 By Benn Hall s - Whizzing through the air at 440.68 The Subway City Grows E 2 E = 30 m. p. h., Lieut. Francesco Angello, Italian By Don Glassman ace, set a world’s speed record for aircraft on Oct. 23, 1934. Today, Premier Mussolini orders his airmen to build planes that will attain speeds of 600 ë ° m. p. h.! Whether or not aircraft will Carleton Ellis—Master Chemist 26 be able to reach such startling speeds is - explained in an interesting article—‘‘Is By Aubrey D. McF adyen There a Speed Limit?”—written by Don Glassman, appearing in the August issue of MM. The photo above shows Major Alford Williams, noted American speed 58 pilot, in the cockpit of a former Schneider Trophy racing seaplane. Fire Walking—Fact Or Fable? By Hereward Carrington World Radio Battle Looms - > ə ə £62 By Roland C. Davies FOR WORKSHOP FANS Among the many inter- esting projects tncluded in the August issue will be— Black Gold From Alaska > ə ə + 63 ice Tear tvosBavare a? Ace: By Paul Conant teur Telescope Making; Ex- periments For The Amateur Physicist; A 34-Meter Radio He Beat The Oyster At Its Own Game ~« 72 | Receiver; Making A Rain By Austin CL "e | Gauge; concluding install- y Austin C. Lescardoura | ment of Build A Bellanca “Gas” Model Plane, and other plans, suggestions, and practical workshop kinks. [Continued on page 8] Published monthly by Modern Mechanix Publishing Co., Fawcett Bldg., Greenwich, Conn., U. S. A. Entered as second-class matter under the Act of March 3, 1879, at the post office in Greenwich, Conn., with additional entry at Louisville, Ky. Editorial offices: 1501 Broad- way, New York, N. Y. Not responsible for unsolicited manuscripts. In U. S. and Possessions and in Canada, 15¢c a copy; $1.50 a year. Send subseriptions to Greenwich, Conn., address. Other Postal Unions, $2.00 a year. Printed in U. S. A. Advertising forms close the first of second month preceding date of issue. Advertising offices: New York, 1501 Broadway; Chicago, 850 N. Michigan Ave.; San Francisco, Simpson- Reilly, 1014 Russ Bldg.: Los Angeles, Simpson-Reilly, 536 S. Hill St. Member Audit Bureau of Circulation. W. H. FAWCETT, Publisher RALPH DAIGH. Managing Editor ROBERT HERTZBERG, Editor At ALLARD, Art Director THOMAS A. BLANCHARD, JOHN L. SCHERER, CLIFFORD PETERS, Associate Editors ROBERT PAGE LINCOLN, Hunting and Fishing Ccnsuittant $S. S. RABL, Naval Consultant

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I. takes brain to earn money—trained brain! The man without training is usually the man without cash. You can train your brain! Thousands of men have done it through spare- time study of I. C.S. Courses. Be a cash man—be a trained man—mail this coupon! , 3 2 ee INTERNATIONAL CORRESPONDENCE SCHOOLS * O Architect O Architectural Draftsman O Building Estimating OJ Contractor and Builder O Structural Draftsman (J Structural Engineer [] Management of Inventions 0) Blectrical Engineer [] Electric Lighting O Welding, Electrice and Gas O Reading Shop Blueprints O Heat Treatment of Metals CO Business Management CO Industrial Management O Trafe Managerment C Accountancy O Cost Accountant O C. P. Accountant O Home Dressmakiag SLT as vė Tf you reside in Canada, hey send BOX 2321-M, SCRANTON, PENNA, Without cost or obligation, please send me a copy of your booklet, “Who Wins and Why,” and full particulars about the subject before which I have marked X: TECHNICAL AND INDUSTRIAL COURSES O Sheet Metal Worker O Boilermaker O Telegraph Engineer CO Telephone Work D Radio O Mechanical Engineering O Mechanical Draftsman O Machinist O Toolmaker O Patteramaker O Diesel Engines O Aviation Engines O Automobile Mechanic O Refrigeration O Plumbing O Heating O Air Conditioning O Steam Engineer O Steam Electric Engineer O Marine Engineer O R. R. Locomotives 10 R. R. Section Foreman D Air Brakes O R. RB. Signalmen O Highway Engineering O Civil Engineering C Surveying snd Mapping O Steam Fitting O Ventilation BUSINESS TRAINING COURSES O Bookkeeping CJ Seeretarial Work D Spanish O French Salesmanship O Advertising [] Service Station Salesmanship (1) First Year Collese Subjects O Business Correspondence O Stenography and Typing O Civil Service O Maii Carrier Railway Mail Clerk DOMESTIC SCIENCE COURSES (] Advanced Dressmaking 1] Professional Dressmaking and Designing this eoupon to O Millinery * O Bridge Engineer O Bridge and Building Foreman O Chemistry O Pharmacy O Coal Mining O Mine Föreman O Navigation O) Cotton Manufacturing 1) Woolen Manufacturing O Agriculture O Fruit Growing D Poultry Farming O [] Fire Bosses Grade School Subjects O High School Subjects O College Preparatory D Ulustrating O Cartooning O Lettering Show Cards DO Signa O Foods and Cookery (i Tea Room and Cafeteria Management, Catering DP RUEG vexcnnasnsnkeoneanssvesesitsaannasvimasisest eisiisuse snbuavtasunareassarsiseaccesgyegusieces Eass A O E NE ASN NO SEERE r E Tramen Tra a Ni asa her. A } > Answering sidvertisements Please Mention July Modern Ee cone ae beea eee PHCSCHE POSTEO cc caisccrisrectennWeivorsivscentwoenpenssaesies the International Correspondence Schools Canadian, Limited, Montreal, Canada A { Ei h ER Ly

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AVID SARNOFF, once a poor lad e and now the famous President of the Radio Corporation of America, in an article in Liberty Magazine states: “Civilization means elimination of un- necessary labor. The sewing machine and the vacuum cleaner save millions of women from backbreaking toil. The tractor makes the farmer’s life bear- able. The automobile lends wings to us all. The airplane is our magic carpet. It would be madness to slow up invention because our trouble is not that mechanical science moves tco speedily, but that the governmental and secial sciences move too: slowly ... In a world reorganized to vibrate within cértain wave bands, human intelligence will be able to dis- tribute equally nature’s boun- ties from above and below, and make princes of paupers.” *® Since the ‘‘Horseless Buggy” Days, We have Helped Inventors ERHAPS you have already heard about our firm, because one client tells another—and we have served men in every state in the Union, and in nearly every Simple Inventions Vi ay is foreign country. We have been working with inventors since 4 F i| t G : 1898. If you have a good inven- ave xce en om tion—or an idea for one—and don’t know what Victor J. Evans mercial Possibilities & Co. can do for you, NOW is the time to find out. FREQUENTLY inventors confuse the size of the complication of a device with the question of commer- cial value and patentability. These How We Can two factors, of course, have no re- @ ey 9 lation to each other. Most of our W ii f t Help You : present-day complicated machines Both the Patent Office and the represent a process of evolution, a U. S, Supreme Court have made it se-ies of inventions. On the other VER since George Washington clear that the inventor needs the hand, every so often some inventor signed the first patent, America assistance of a competent patent comes along with a very simple has led the world in inventions. It lawyer when it comes to protecting “gadget” which possesses the ele- may be said that not a year has gone an invention. It is one thing to think ments of broad utility and is patent- by without some important inventions up a good invention—it is another to able. Some of the most profitable in- being patented and commercialized. Ret Pere patent acre ee ventions have been of- this latter David Sarnoff, president of the Radio he be to ove class. Shown above are a few such Corporation of America, sees a big sound advice and counsel to in- examples. Whether a device is simple future ahead for science and inven- ventors. Our free books (described or complex, if it represents a forward tion. Just as sure as the sunrise, 1937 on the opposite page) tell what steps step to save manufacturing costs, to will see new inventions come out— to take first, how to protect your- save labor, or to add enjoyment to new wealth made from patents. Your self, how the laws protect you, what human life, it may prove patentable tien maw be ous of then. Moa. Keven you must do, when to offer your in- and profitable. This subject 1s more k sie could vention for sale, how others have fully discussed in the booklet en- can tell. For this reason you shoul succeeded, and much more, You need titled “Patent Protection” shown on send for our books today and get the this information, the opposite page. facts about patents and inventions. 6 Accept No Substitutes! Always Insist on the Advertised Brand!

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ae i 7 These FREE books tell you Get the answers to your questions: How can I protect my invention? : When can I show my invention to TORNE ENES : RRS MET E CORRE pi i 4 «manufacturers? When can I offer sE oe ; me 3 eee ‘4 it for sale? How should I go about selling it? Can I get protection with- out a patent? What are my em-

The U: S; bas Liberal pat : 8 | ployer’s rights? These and other im- eae Rian and Me ME Oe Ie Mi Ba VIA 4 portant questions are fully answered. much of our national wealth is based on pat- ents. In. tact, a Japanese com- mission decided that American progress was mainly due to our patent laws. These laws are made to protect you. Find out about them now, This is for your own good, Vans es Ee SA ; j SE RA ji AAAI

Mail Coupon Today Delays are dangerous. If you have a good invention you should get protection for it just as soon as possible. Don't turn this page until you have clipped and mailed this coupon—vyou will hear from us by return mail. ñ & 2 i washi iG apio- N er pork I Qe purl 115 Mechanical Principles other Offers? yi, Moire BME» gan Francie Leer pmpve “nac., $a les a csgy hee ob povar, ters Los Ans”. protection ang py any 10 *aaauTtits 2”. 6s Patent Taes SU . : Shown 730-B ap vout pooks., k Same ook = io. OF eM (rott. z et a ie "ot > S ell vou what to ao and FM Tices B'S xi to inventors). Not only does it tell y n panch © ca ge r en for protection, and how to do it—it also shows you ii ee EE agra sa P S 115 different mechanical movements that you may Name =t ee a orien i . . Eau - 5 a : ° iC K- } rentors , -aanu n ro Ne pa PON ec” ase iñ developing your OWT m entions. Inv street and NO ance 8 tell us they have found these useful. eae ity 2 GS i He a 8 Se Ge os When Answering Advertisements Please Mention July Modern Mechans ST

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Shows How to Make $15 to $25 weekly in Spare Time | $35 to $60 Full | Time in Radio Do you know that ambitious men are making good money in Radio—that many are earning $10 to $25 ina week in their SPARE TIME—that even a cripple in a wheel chair is making a good living in Radio? Do you realize that YOU ico ean cash in fast? This is a FACT, and I prove it in my free book. PROFIT BY MY NEW TRAINING Twenty-five million Radio sets in this country require service and parts—just like autos. With my training a man can make from $5 to $25 a week in spare time. From good spare- time earnings you can quickly step into a busi- ness of your own, or a full-time job at good pay. I train you right in your own home—teach you Radio thoroughly—furnish you a big pro- fessional outfit—and give you my ‘Business Builders’? showing how to make the money. Earn while you learn. Fit yourself for a better job. Get the FACTS! Send for my FREE BOOK today! F. L. Sprayberry, Pres., Spray- perry Academy of Radio. “The equipment you furnish is all a man needs to get a good start in the Radio business’? — Suecessful Student, H. Hall, Balti- Md. more, READ THIS! This is no ordinary “correspondence course.’? I furnish you with a complete PROFESSIONAL RA- DIO outfit — exactly what you will find on any service-man’s workbench: Genuine tester. Bie set of manuals. Complete tools. Extra parts. Even an ‘Electric Eye’! O EEIN EOI ORT F. L. SPRAYBERRY, RADIO, Office No. 15-H, WASHINGTON, D. C. Please send me, without obligation, University Place, of training. Ol ee csc sinmwecmmoemee n= State... m Paste this coupon on a penny postcard and mail Today. SPRAYBERRY ACADEMY OF *‘Vfore Money in Radio’? and complete facts about your new type -— s s w. E | NAME and - ADDRESS - ate LEFT NE W COOK and BA Slips into Any Old Range or wren, OF Cecking Stove; Does Away tr, Mg a = lAa, aan _ a — With Coal or Wood; No Dirt or Ashes; Hotter, Cheaper. Cooks a Meal for Less Amazing oil burner which many users say beats any ever gotten out, burns cheap oil a new way. without pre-generating or clogging up; gives intense heat at less cost by turn of valve. One free to one person in each locality who will demonstrate and act as agent. Write quick, be first to learn A S wK P =. “os AGENTS Salesmen BIG MONEY how to end drudgery Its sweeping of coal and wood and the country. make big money spare GET YOUR or ae a le OWN BURNER postear oday. FREE UNITED FACTORIES nn MEK J-600 Factory Building REAL MONEY. Kansas City, Missouri Write quick. tyvee CHEAP OIL BURNER KE Without Coal Wood COOLER KITCHEN IN SUMMER g Accept No Substitutes! Always Insist on the Advertised Brand! CONTENTS—Continued from page 4 SHORTER FEATURES World’s Largest Switch—Frontispiece - - 39 Heart Operation Performed On Roach - - 40 Russia’s Air-Minded Women - - - = - 49 HOW-TO-BUILD FEATURES Build A Bellanca “Gas” Model Plane—Part 1 76 Building “Arlen Special’—A Midget Racer— Part II = =~ = - - - - 82 Rigging And Painting Complete “Flying Cloud”—Part IIT - - - - - - - -~ 8&6 Washing Machine Motor Powers Unique “Tri-Bike” =- =- = =- = = = = = = 90 Make Artificial Lighting With Giant Oudin Coil - - 94 Home Repair Problems That Are Easily Solved = = m že E S m = OG This Individuality Table Is A Profitable Workshop Project - - - - - - - - 9% A Midget Superheterodyne For Ten Dollars 102 Tapped Metal Accessories For The Home Study Desk - - = - = = - = = = 104. Converting An Auto Engine For Marine Use 106 ‘Instant Photos” Made With Ordinary Camera - - - - - 110 Photographing Animals At Night - - - - 112 Camera Kinks - - =- =- = =~ = = = =118 NEW MECHANICAL INVENTIONS Dental Office On Wheels Visits Outlying Towns - =- = = = = = = = = = = 33 New Bottles Can Be Stacked - - - - 39 Kinetic Energy Motor - - - - - - = 39 Radio Bares Oil Line Taps - - - - - - 39 Midget Streamlined Locomotive Thrills Crowds = = = = = = = = = = = 41 Apparatus Detects Gases - - - - - - 4l Flashlights Get New Bulbs - - - - - - 48 Meat Is Delivered In Mechanically Refrig- erated "Trucks = = = = = = = = = 655 Truck Carries Own Trailer - - - - - - 6l Mobile Microphone Boom Aids Voice Pickup 69 Transportable Transformer Fills Emergency Need - - - =- - = = = = = = = 65 Improved Gyropilots Adopted By Aircraft Operators -= =- = = = = = = = 66 Circuit Improves Radio - - - - - - - 66 Streamlined Engine Hauls 15 Cars At 80 M.P.H. —- = ee = me ke oe me ee = Micro-Wave Tube Produced - - - - =- TI [Continued on page 12]

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Business Demands Accountancy —because Accountants Command Business A better than av have been in demand — at far O. D. always thought stories about LaSalle training were fairy tales until the training helped him—a clerk at 975 a month—move up in six months to $125, and within four years to $250. Today he is General Auditcr es of a large national organization—and his income ee is more than seven times his starting salary. “ae As an assistant bookkeeper in a great Western bank, C. F. H. looked forward to slow progress. But LaSalle accoun- % better than average earnings. But teday—more than ever before—the compe- tent accountant finds his servicesat a tremendous and increasing premium. In the depression business tightened up the reins and is watching costs—prices—every move—striving to operate on that basis of close control so essential to profits. Then too, progressive business is building now for the return of prosperity—laying plans for expansion, for new processes, new markets—getting ready for the un- paralleled opportunities of the next ten years. The Home Study Way to | Accountancy Success ! Thousands upon thousands of men have trained for Accountancy with LaSalle at night—at home. Their success—their progress—is a matter of record. Whether their goal was a C. P. A. degree or advancement in business, our files are full to overfiowing with letters reporting income increases so far out of line with the time and cost investment that there is no comparison. Note, for instance, these four typical cases chosen out cf thousands more we might cite. (Names on request.) F. F. A. was a railroad yard clerk at $112 a month when he began accoun- tancy training with LaSalle. Five years later, hisincome was 500% larger and he was a Certified Public Accountant and attorney. F.C. was 22 years of age and general all-around man in an Arkansas lumber yard at $75 a month. Five months later, his firm made him man- ager at $125, and ten months later promoted him to a larger yard at $250 plus a commission on sales. O Business Manage- ment O Expert Bookkeeping OC. P. A. Coaching Cl) Railway Station Management LaSalle Extension University LA SALLE EXTENSION UNIVERSITY, Dept. 7493-HR- CHICAGO Opportunities in Accountancy—Check below and we will send you a free copy of “Accountancy, the Profession that Pays,” also information about our new training in Higher Accountancy, all without obligation. C Higher Accountancy Other LaSalle Opportunities: If more interested in one of the other fields of business indicated below, check that; OLaw: LL.B. Degree O Business O Commercial Law O Industrial Manage- ment ORailway Accounting (Modern Foreman- O Traffic Management ship / tancy training speeded up his climb to Assistant Trust Officer and to a salary increase of 400 per cent. These Men Won Success in Ordinary Times— You Will Profit by Coming Prosperity 7 Remarkable as is the success of thèse men— you will have a decided advantage over them—you will be entering accountancy when unusual business conditions work with you for success. Present conditions and theupturn to prosperity not only call for more capable accountants— but offer unusual opportunities for both quick and permanent success. Theaccountingstudent of 1937 will face real opportunity in 1938 and the accounting leaders of 1940-45 will be largely determined in 1937-1938. —If You Can Qualify Ask yourself three questions: 1. Are you ambitious? | 2. Have you determination ? 3. Can you see and grasp an opportunity? If the answers are ‘‘Yes’”—you are qualified. If you have determination; if you are am- bitious; if you can take advantage of cir- cumstances — prove it by investigating. A two-cent stamp, sixty seconds time, and the coupon below will bring you full informa- tion regarding Accountancy training and the opportunities to which such training leads. Then you can judge intelligently. Correspondence Ol Stenotypy Ol Modern Salesmanship [| Effective Speaking ğ Oi Business English When Answering Advertisements Please Mention July Modern Mechanix

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STEP NO. ONE Make a rough pencil sketch of your invention, describe it fully, and send it to us for pre- liminary search through United States Patents in the U. S. Patent Office. A Se pn STEP NO. TWO Our trained searchers will then make a preliminary search of the pertinent U. S. patents to determine if your invention is probably patentable. = mn Hy STEP NO, THREE Our complete report of search and opinion on patentability will be mailed to you with copies of U. S. Patents that we consider nearest to your in- vention. STEP NO. FOUR if you decide to make patent application, for customary fees explained in our booklet, our draftsmen will make drawings and proper papers will be pre- pared for presentation of your invention to the Patent Examiner in U. S. Patent Office. 10 Accept No Substitutes! CULL KNOW HOW TO START KNOW EACH STEP TO TAKE Before Going too Far with Your Invention o] Very often, the patent procedure is what we call a ‘‘simple’’? one— as illustrated here. Our FREE BOOK, ‘*Patent Guide for the Ln- ventor,’’ describes what to do and how to go about it. Send for it by all means—let us urge, however, that you take the first step (Step No. 1 at left) without further delay. It will prevent wasted work, mis-steps, and going ahead ‘‘in the dark’’—your whole patent pro- cedure depends upon the first step. If you have an invention that is patentable—and want to secure for yourself your inventor’s sole right to profit from the invention—you can’t afford to lose time in securing the protection of a U. S. Patent, Other inventors may be working on the same thing right now. Should they develop this invention and file patent application before you do—the burden of establishing priority will be upon you, Our Big Book—‘‘Patent Guide for the Inventor’’—will tell you the quickest possible way to secure Patent Protection for your invention. SEND FOR IT TODAY! Immediate Search Necessary A Search at the U. S. Patent Office will disclose one of three things: That you have hit upon an entirely original invention-—that you have suggested patentable improvements upon an existing invention—or that your invention has been anticipated throughout, and you should drop it. You should have this information at once. The next steps (the whole procedure of obtaining a patent) will be thoroughly ex- plained to you in our FREE BOOK. Our FREE BOOK tells everything you need to Know about patents. We will mail this book upon receipt of your letter requesting searen —or if you want to read it before having search made, simply till out the coupon on opposite page. FREE RECORD OF INVENTION è è è This FREE Record of Invention Form en- ables you to make in convenient form a sketch of your invention and have it wit- nessed in a manner of value to you should the occasion for evidence arise, MAIL THE COUPON TODAY and ob- tain our FREE BOOK and Record of Invention Form, $ i A ot CLARENCE A. O'BRIEN & HYMAN BERMAN 3172 Adams Bldgs. Washington, D. C. Registered Patent Attorneys Before U. S. Patent Office Always Insist on the Advertised Brand!

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DELAYS ARE DANGEROUS IN PATENT MATTERS The Free Book shown here must take to secure a PATENT. ONCE. must furnish your attorney, and what steps he must take in order to protect your interests, member, inventing an article is one thing —securing the exclusive right to manu- facture it, use it, or sell it is another. Without a U. S. Patent, you cannot expect to reap the profits that your invention may make possible. Send at once for this book. After you get that, yowll know exactly what tò do to protect yourself. WHAT A PATENT DOES FOR YOU Every vear thousands of Patents are ‘ranted. Very few, however, represent Phe discovery of entirely new principles. Most of them provide new methods of do- ing some everyday thing in a better way —changes for greater efficiency, useful- ness, adaptability, or beauty in some pre- viously Patented thing. These IMPROVE- MENTS are Patentable if new, and ac- tually represent new inventions. These improvement Patents offer large chances for profit if commercially useful. The business world wants improved products and services. WE SERVE YOU QUICKLY AND SECRETLY Anything you write us or strictly confidential between us. All letters and drawings are kept in strong, steel, fireproof files, which are open only to ourselves or authorized members of our staff. We have se- cured patents for inventors located in every state in the Union. Our organi- zation is a large and efficient one. Our practice is confined entirely to Patents, Trade-Marks, and Copyrights. We have had years of experience in Patent Matters. When you place vour invention in our hands, we are in posi- tion to proceed at once to secure pro- tection for you. Our fees are reason- able, and, if vou desire, we can arrange convenient terms of payment. IMPORTANT! Please understand that vou under the slightest obligation in send- ing for this book. We will mail it. together with the Record of Invention form, the same day we receive vour request. Use the coupon to save vour- self time and trouble. After that, vou send us is are not will be in position to proceed or not as you choose, to make your application for a patent. When Answering Advertisements Please Mention July Modern Mechanix ee Se ee ee ee ee ee en ee se eae a ee a ee eee es ee was prepared for inventors, to show them exactly what steps they If you have an invention, you should send for this book AT It will tell vou exactly how an application for a Patent is made, what information you Re- THis FREE spook oeoo Tells How / How your Patent Ap- j plication is madle? $ what kind of sketches / or drawings are nec- essary; what other papers must be made out; how the Patent Laws protect you; why itis important tie, to avoid loss of time in getting your application filed; and many Í other important j points. Even a į very simple in- ; vention, if new j Š ; f and useful, ; may prove # very valuable. You may have much to sain and nothing to f lose by f sending for pes this book ; CLAREN CEA.O’ yt € HYMAN BERMAN 3172 Adams Building WASHINGTON, D.C. REGISTERED PATENT ATTORNEYS BEFORE U.S. PATENT OFFICE Please send me at once your Big Free 48-Page Book, “Patent Guide for the inventor” and your Speci ially Prepared “Record of Invention” form. This request does not obligate me. D E E a E E an ry ee ae O ADDRESS sorang en UST 6 SSE BTWG GF ESS Nn d yS pS a S a PLEASH WRITE OR PRINT NAME PLAINLY Poe we a ss se es es mas 11

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CONTENTS—Continued from page 8 Electrici at your Tin Electric Fan Fits Purse - -° - - - - - T1 Small Utility Tools Are Attached To Finger- pS =- = = = = =e ete = = ow = £4 Cre NDEZ ELp oE DE Ezy WWDELF ; Singly nk NEW -| NEW -ENEK F AEW FAZE I UNEW I. S ecial Truck Rec T i 14 ELETRIC eTRIC Hite sf l overs la Ps : a Ta ce LECTRUC FELECTREC FELECTRIC HELTCTRI Price = Teme ores SM IVEY $1.50 FOR THE WORKSHOP FAN pir he AUtLENay as F Shute PULES = J2CMOTORS F TESTING MATING TACHUTORS £ RELAYS `E WIRING CURRENT WINDINGS LERDEISERS MUSE Lt } theres MSTRUMENTS gy NDINI SEKSE EUGHT = 9 3 hi patra nau] Eis Dota ecg mt feos oneng Book | Workshop Hobbies - - - - - - - - 1 ATURE PMMANCE | STORALE I Fowgp - anien METERS Pea Tension ; Px SHUTS ETT OH Nisy ON > Bs . Z s fanien fan Sre a aanst a Projection Box Makes Sketching Easy - - 8i me Fn LE MEIAIAS.. forces ican | È PACTICE vis ni = a = = a S . . e N L E Bae Tin Can Creates Smoke Rings - - - - 8l a eis About-The-Home Handikinks - - - - - 93 Leng Ropes Remotely Control Garage Doors 108 S FINITE e eera À Sri a i I ee | Rear Mirror Improves Vision - - - - - 108 Parts Tray From Battery Box + = = = -%108 PHOTOGRAPHY ¢i, TIONARY Yi Sees 4) A | g X | wi er eA Ny ueit il l i Tea || LA DER i + P \NGi | 9000 Words STERN sob ii, F AUDELS NEW ELECTRIC LIBRARY—A progressive Home Study and Reference Course’ in applied electricitv. Easy to understand. Ques- tions and answers plainly written for a complete working knowledge of modern electrical practice, necessary to every electrician, engineer, mechanie and student, ie LEARN THE AUDEL WAY! You ask the question—Audels New Elec- tric Library gives the answer—9500 simplified outlines, graphic illus- trations and precise explanations covering Construction, Operation and BOOK A MONTH PLAN Order tl lume that interests you—today! -1 a —Order the volu £ sts — l . We will send that volume on 7 days’ free trial. If the book helps Camera Kinks - =- = = = m m = = = 113 you, send us $1.50. If it does not help you, mail book back to us. On receipt of your first payment, we will send your, second book. Darkroom Aids For Amateur Photographers 114 We allow 306 days to pay for this and for each following book until E 2 you complete the Series. , a j Candle Stops Frilling Of Film Edges - - - 114 Jf you are not satisfied, you may cancel your subscription at any time. JAAA ‘Theo. Aui a con 49 W. 23rd St, New Serie ise Newspapers Make Substitute Blotters - - 114 Theo. Audel & Co., 49 W. 23rd St., New York City Tail Vol. I, Electric Library on 7 days’ free trial. If ge > . -m m s w= TD OK. T will remit $1.50, otherwise Iwill return it. Bent Ferro plate Dries Prints 114 I also request you to mail one book each month on same terms. No obligation unless I am satisfied. Amateur Photo Puzzlers -= = — =— = =~ 116 EXAMINATION COUPON @-@ @ @.e: ee u atao see ep @envaoeeee Niece, & wiewis as a. SSE ome mn nea ae DEPARTMENTS Oceupation ssa scese sses WD e PIYA Random Chips From The Editor’s Workbench 14 Solving The Readers’ Problems - =~- = 26 Nic Sprank’s Science Oddities - = = = S Workshop Hobbies - - - - - = = - 75 ...the Radio Sparks - - - - - - - = = = 101 PADLOCK New And Timely Kinks For Motorists - - 109 dil Amateur Photo Puzzlers - - =- - =- = -116 MISCELLANEOUS Smithsonian. Gets 1902 Car - - - = = 83 Six-Foot Ship Model Features Radio Control 39 Model Steamship Functions - - - - - 41 Model Trains Actually Run - = = = =a 48 Chureh. Goes To Sea-- - =- =- = = = = 48 Trailer Camp Brings Back Tepees For Sleep- Ing - =- - - =- = = = = = = = = 55 Customer’s Car - - - - - - = = = 99 Scrap Metal Becomes Engine - - - ~ - 6% Swamp Furnishes A!l Material For Unique House - - - - =- =- = - = = = - 61 Concrete Weight Cut - - - - - = - 65 Schoolboys Build Model Rockets - - - - 66 Crane Serves As Temporary Ship Lock - - 67 Angler’s Kit Carries Motor - - - = - 67 U. S.-Soviet Air Line Planned - - = - 67 Botany Taught In Solarium - - = = = 74 Master Jock (@.. Milwaukee World’s Largest Exclusive Padlock Manufacturers | | | Hose At Gas Station Entrance Announces OVER 52,800,000 IN USE 12 Accept No Substitutes! Always Insist on the Advertised Brand!

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To help you answer these $ questions: What are today’s = opportunities in Drafting? a Will f like the ieee . 7? = work? Can Í learn Draft- "ing readily? 2 drafting Free Drafting Opportunities Growing Daily Before anything can be made or built, the Drafts- Prove That You Can Qualify man first must draw it. Building trades, transportation, The 2 lessons will be sent absolutely with- - - i pa ' y+ 4 out obligation. In the privacy of your own manufacturing — ALL depend on him. That is why any SE ee ee eee pickup in any line means first call for the Draftsman! —how gradually you areled step by step—how thoroughly you master each point—how, as Fit Yourself for a Job with a Future time goes on, you can pass granri i i al to complete mastery of Drafting—able to get Drafting welcomes ambitious men — offers good pay to and holda pisdsant, profitable steady Jon Auei start, with splendid opportunities for promotion. Ore of the aaO co Gust mail the coupon! ,, : ` gy ee NOW, s0... just mail the coupon! steadiest of alllines. Right from the start, the beginner works side by side with experienced men—inking in their drawings, making tracings, constantly profiting by his contact with ee mee Pema s RANNAR ieira Mee dorianp ți Se f aajo dnai eeey ws ee eon es, pane + “ seas” seasoned engineers. The “higher ups” see his work. If it is | instruments and 4 sa neiples of the | good, advancement is sure and steady. aa paed. O E sptos ETN E PO eine $ AP Ahi Pleasant, well-lighted offices are the Draftsman’s work- room. He keeps regular hours, with congenial, high grade fellow workers. The work is fascinating—embraces not just one line, but hundreds. Drafting Experience NOT Necessary You can master Drafting readily by home study because you learn and advance exactly as professional Draftsmen wal ee ees eget and tramin poate: s omal ci og working conditions are duplicated to the final detail. Thou- T sands of successful graduates enthusiastically endorse Amer- „Mail Co veon, for 2 Le S sons FREE _ ican School methods, nowhere better exemplified than i E American School, Dept. DDB 28, our Draftin © Course., g Drexel Ave. at 58th St., Chicago a g Without theslightest obligation, send 2 beginning Draft- We want you tosee for yourself—before you come to ANY ing Lessons and free Bulletin. I am not to return them. oo eae tee 2 E decision—exactly what Drafting is like. We want you to E ome eee judge your own interest in the work—and our ability to : SE eee teach you. So we make this 2 Free Lesson Offer. E Aarne anaana A American School, Drexel Ave. at 58th St., Chicago, Il. -E Bitpsclcccencencs aa gate aaa A nee ade When Answering Advertisements Please Mention July Modern Mechanix 13

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Using MM plans, 75-vear-o'd W. L. Farmer, of Waukegan, lil., constructed this novel and attractive typewriter desk. It provides ample room for a typewriter, letterheads, and books. KADERS who own typewriters and desire a to possess a compact cabinet-desk that is not only attractive, but which features space for paper, books, and other items on a scale not found in ordinary desks, will -do well to follow the example of W. L. Farmer, of Waukegan, Ill., and build one. His letter, which was awarded the first prize of $5 in this month’s Workbench, states: Dear Editor: I am enclosing photos of the typewriter desk I built from plans that appeared in the February issue of MM. The desk not only excites the admiration and envy of all my friends, but it is the most comfortable and convenient typewriter desk I have ever used, which is saying a lot. The excelience of MM plans deserves loud acclaim when a 75-year-old man with bad eyesight and pos- sessing only a few aged hand tools can produce a desk like this one. My desk features a small secret compartment, access to which can only be gained by the initiated. W. L. Farmer. Our sincere congratulations are extended to Mr. Farmer. His craftsmanship surpasses that L o* many younger men. Rokok Midget racers still roll from home workshops 14 in increasing numbers. A let- ter from Tom Nicolosi, of Kan- sas City, Mo., describing his racer was awarded the second prize of $3. He writes: Dear Editor: I am sending a photo of my midget racer. Built by my brother and myself, the tiny car is powered with a 34 horse- power engine and travels about 25 m.p.h. The gas tank holds a quart of gas which takes the car about twenty miles. I enjoy your articles on midget racers and hope you will run more of them. Tom Nicolosi. Tom and hundreds of other MM midget racer fans will un- doubtedly enjoy the article on the Arlen Special front-drive racer continued on page 82 of this issue. We will anxious!y await photos of the first Arlen Special to be completed by an MM reader. kokok The boating season being full upon us, it was only natural that we received more photos of completed boat projects than of any other type of project. One of the best project letters was received from Arnold L. Topham, of Bangor, Me., winner of a third prize of $3, who wrote: Dear Editor: Here is a photo of my “Moth” class boat which I built from MM blueprints. I had never built a boat before, but this little craft was easy to construct. Traveling 20 miles on a quart of gasoline at a speed of 25 m. p. h., this midget racer is powered by a *4-horsepower en- gine. Tom Nicolosi, of Kansas City, Mo., is the proud owner. Modern Mechanix

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And—tis she fast? I think I have the classiest and fastest boat on the river. I think MM is a fine magazine and I have studied your “How To Build 20 Boats” books from cover to cover. They certainly are complete and I’m anxious for another issue to appear. Arnold L. Topham. We don’t blame Topham for being so proud of his Moth. She certainly appears to be a trim and well constructed job. Hs oh ae When a boat fan builds one boat it’s news, but when he builds two of them it’s more news. Eugene Trivaudey, of Litchfield, Conn., is the reader whose double boat project was awarded fourth prize of $3. His interesting letter reads: Dear Editor: Last fall a friend of mine loaned me two issues of MMi from which I built the sailboat “Nomad.” Since then I have become very much interested in boat building. During the Spring I buiit “Sun Ray” from your boat book plans and gave it to my nephew. We both belong to the same boat club and the two heats have been consistent trophy winners. I am look- The cockpit of this trim Moth sailboat looks very inviting as ig forward to a new boat book so please hurry it it noses against a pier. It was built from MM plans by aleni Arnold L. Topham, of Bangor, Me., who claims it is very fast. I have found your magazine very interesting, par- ticularly the home workshop section. Please keep up Stuart Joyce, of North Hollywood, Calif., was the good work, awarded a $3 prize for his project letter, which Eugene Trivaudey. states: It pleases us to learn that the two MM boats are Dear Editor: consistent trophy winners. It is conclusive evi- I have just completed a “Handy Henry” Ford dence of Trivaudey’s craftsmanship and speaks tractor built from MM plans. The machine has proved well for MM boat book plans. [Contthued on page 16] Eugene Trivaudey, of Litchfield, Conn., liked MM boat plans so much that he built a Nomad sailboat (left) for himself and a Sunray for his nephew. Both boats proved the excellence of their design and construction by winning trophies. July. 1937 15

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NEVER TOOK A LESSON FROM A TEACHER —yet Bob is the envy of his music-loving friends You, too, can learn to play any instrument this amazingly simple way. No expensive teacher. No needless exercises or practicing. You learn at home, in your spare time. Yet almost before you know it you are learning real tunes! Then watch the invita- tions roll in—see how popular you become. Yet the cost is only a few cents a day. Easy Method You don’t have to be “talented.” You can’t be too young or too old. No teacher to make you nervous. Course is thorough, rapid, simple as A-B-C. First you are told what to do—then a picture shows you how to do it—then you do it yourself aud hear it. In a short time you be- come the envy of your friends, the life of every party. Demonstration Lesson Free Write today for Free Demonstration Lesson, together with big free booklet which gives you details and proof that will astound you. No obligation. Instruments supplied when needed, cash or credit. U. S$. School of Music, 2627 Brunswick Bldg., New York, N. Y, HANDE: TOOL OF 1001 USES Grinds - Drills - Cuts - Polishes : Carves ~ Routs ~ Saws - Sands Sharpens - Engraves A whole shop full of tools in one for work on all met- als, alloys, bone, resins, glass, / stone, wood, etc. Uses 200 * accessories. Saves hours of rite tedious work. 13,000 r.p.m.% Socket ACor DC, 110 volts. $10.75 and up, postpaid. 3 i i LEARN TO PLAY BY NOTE Piano Guitar Violin Saxophone Organ Mandolin Tenor Banjo Hawaiian Guitar Piano Accordion Or Any Other instrument Accessories Free. DE LUXE MODEL For constant service, nothing com- pares with this easy-to-handle pro- duction tool. Saves time and labort. Fastest, smoothest, most powerful tool for itstypeand weight. 25,000r.p.m. $18.50 postpaid, 6 Accessories Free, Get a Demonstration at Your Dealer’s or Order Either Model on 10-Days Money- Back Trial. Catalog Free. CRAFISMAN’S PROJECT BOCK “Pleasure and Profit with a Handee”’ Easy working plans for making many G interesting and unusual projects, 25c stamps or coin. te # : 2102 W. Monroe St., Depi., H Chicago Wheel & Mig. Co. Chiteene Hineie + tem ë ees n a- eee ee ees H eee a a a eo aa a GU ee Å 1 O Send Catalog O Project Book ~ { O $10.75 Model [| be Luxe Model O Send C: 0O. D. MM1-7 j i j ET ate cc ae a Gee ay Gaal A eb DR ae aaa cc Ginigiin Gas! Mie ce ans Ecs aa A E A T 5S ee 16 Accett No Substitutes? Alwar ° ’ sop ek L YS Insis Editor's Workbench Chips [Continued from page 15] Powerful enough to do the work of three horses, this "Handy Henry” tractor was constructed by Stuart Joyce. Metal cleats replace the tires when the tractor is used on adobe soil. to be very satisfactory, doing the work of three or four horses with ease. The wheelbase is 70 inches to permit short turning. Metal rims and cleats replace the rubber tires when I use the machine on adobe soil, the tires being used only when plowing sandy soil. Sandbags are used for weight to insure traction. I did all the work in building the tractor with the exception of some welding, the total cost being only twenty-two dollars. A few jobs and it will pay fer itself, Stuart Joyce. It is doubly satisfying to construct a tractor, both for the pleasure and pride of craftsmanship involved and the fact that through its use one can often earn a few dollars. Good work, Joyce. ate ate te > n> “= The Bellanca “gas” model project that starts on page 76 of this issue should have great appeal for the army of model aircraft fans who read MM. By starting construction at once, interested readers will be able to complete the model in time to enter it in some of the contests that are scheduled to be run at various airports through- out the country. The flying of “gas” models has increased tre- mendously during the past year and undoubtedly will continue to do so. Next to piloting a real airplane, there are few hobbies that afford the thrills encountered while launching one of the “put-putters.” With miniature gasoline motors increasing in efficiency while decreasing in cost, it will enly be a matter cf time when the flying of “gas” models will supersede the butiding and flying of large rubber-band powered models. ois of sf Talking of “gas” models, a letter was [Continued on page 18] on the Advertised Brand!

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Beginning Lessons in is Your Job Safe? Just as the gasoline engine changed or wiped out the jobs of thousands who depended on horse-drawn. vehicles for their living—just as electricity changed of light and power—so now the Dieselengineisfastinvading both the power and transportation fields, and threatening the present jobs of thousands of workers. If jobs in your line are steadily growing scarcer, you owe it to yourself to investigate this new, progressive, uncrowded line, that in our opinion will offer good openings for the next 25 years. the entire set-up in the fields | American School, Diesel engines— because of their high efficiency, dependability, and economy of operation—are fast replac- ing steam and gasoline engines in power plants, motor trucks and busses, loco- motives and ships, aircraft, dredges, drills, pumps, etc.—opening up an in- creasing number of well-paid jobs for Diesel-trained men. The field of Diesel Engineering is on the upgrade and con- tinually expanding. It will provide steady employment, advancement and good pay forthose properly trained in this new industry. What This New Field Offers You Now is your chance to get into a big new industry and grow up with it to an important position. Today there is practically no competition in the Diesel field, but the increasing use of Diesel engines will result in keen competition for jobs in the near future. By starting your training now, you Diesel Engineering To Men Over 18 and Onder 40 This offer is NOT open to boys under 18 or men over 40. But if you are WITHIN these age limits, youowe it to yourself to investigate this unusual opportunity. Test Yourself Without Cost See how readily you, too, can earn Diesel At your leisure in your own home, read these 2 Diesel lessons carefully. Judge for yourself our abil- ity to teach — and your ability to learn — this fast- growing new line of work, No experience needed, Diesel — the New, Fast-Growing Power can keep ahead of such competition. You get complete information on all the latest Diesel developments—two- and four-stroke cycles; low- and high- speed and heavy duty types; Diesel- electric generating systems, etc.—in our course. Includes all text material —with special diagrams for quick un- derstanding of this new power. Real Opportunities for Tralned Men Get our Free Diesel Booklet and learn all about this new, fast- growing line—its opportunities and re- quirements. Find out what the Diesel field offers you—how rapidly the Diesel industry has developed during the last three years—the large number of Diesel engines and accessories being manu- factured today—how quickly you can obtain a complete understanding of Diesel engine principles and operstion by home study during your spare time! .. -36 your own pace—without inter- fering with your regular work. Dept. DB28, Drexel Avenue at 58th Street, Chicago Get These 2 Diesel Lessons When you learn what worthwhile op- portunities Dieseloffersand howreadily you can cashinon them through Ameri- can School training, it may mark the turning point in your life. If you are over 18 and under 40, write TODAY for FREE lessons and FULL informa. tion. No obligation. Free Lesson Coupon American School, Dept. DB28, Drexel Ave. at 58th St., Chicago I am over 18 and under 40 years of age. Without obligation, please send me 2 Diesel lessous and Diesel booklet FREE. When Answering Advertisements Please Mention July Modern Mechanix 17

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Built-in adjustable countershaft, com- plete V-belt drive, automatic, reversi- ble power feeds, gears to cut 4 to 96 threads per inch—these are but a few of the extra: features Atlas provides as regular equipment at no extra cost. Send for the catalog. Check all the plus values that make Atlas the outstanding lathe buy today. ATLAS PRESS COMPANY 752 N. Pitcher St., Kalamazoo, Michigan BEALDIRECT...FACTORY PRICES! Many models tose lect from: AC-DCG;All-Wave Farm sets that operate like f city radios! Your nameand f: address on postcard brings fg: you NEW Bargain Catalog f: in colors FREE. Get details of 30-DAY TRIAL plan and agent-user zoposikion! GOLDEN RADIO CO. HeFe DEARBORN, MICHIGAN Here’s a lot of fun and sport. Fly model airplanes, a real popular, he-man sport. Send your name and address and we'll rush you (1) A “H T A” Flyer Glider— long-flying model plane (2) A **Heathe’’ Solid Model Air- plane, complete in every detail, sturdy attractive (3) Booklet “3 EZ’ —Steps to Model Build- ing (4) 16 Page Catalog of amazing HIA games, supplies, sports, and kits. Please enclose 10c coin or stamps to pay postage and cler- ical expense. Write your letter now to: Hobby Institute of America Dept. MM-7 438 E. 98th St., Brooklyn, N.Y. AMATEUR CARTOONISTS IN $2500 Wanted—Amateurs with humorous ideas. No drawing ability necessary. The amateurs of today are the professional cartoonists of tomorrow. Ideas judged and prizes awarded by Applause-O- Meter test before movie audiences. Everyone hasan equal chance. 26 eash prizes in all. Rush name on penny post ecard for ‘*‘Valuable Tips on How to Make Money With Simple Cartoons and Humorous Ideas”, Cash Prize Entry Blank and Rules—SEND NO MONEY. CARTOONISTS’ EXCHANGE Dept. 357-A Pleasant Hill, Ohio Editor's Workbench Chips {Continued from page 16] NIE Woks Readily convertible into a land plane, this 7-foot “‘gas” pow- ered seaplane model was built by Paul Broccard of N. Y. City. Aerodynamically stable, it has made more than 50 flights, from Paul Broccard, of New York City, which was awarded a prize of $3. He writes: Dear Editor: I am enclosing a photo of my latest seaplane model. It is powered by a G.H.Q. miniature gasoline engine and has a wing span of seven feet. The model weighs six pounds including pontoons and engine, and is readily convertible into a land plane. More than fifty flights have been made by the model without a single crackup. Paul Broccard. It would be trite to say that Broccard’s model plane is well built, for the fact that it made fifty flights without cracking up indicates that it is aerodynamically perfect. As the pilots say— “Helmets off to you,” Broccard. ES Readers are invited to send in photos and descriptive letters of their projects for the Work- bench. Just send one or two clear photos of your project with a short note giving a few details and your contribution will be eligible for entry in the monthly contest. When possible we prefer to receive photos in which the builder is shown with his completed project. However, all photos will receive equal attention, so send along your letters. NOTICE Due to the need for larger office space, the editorial staff of MM has moved to the Paramount Building in N. Y. City. However, all orders for blueprints and MM publica- tions should be sent to our Greenwich, Conn., office. 13 Accept No Substitutes! Always Insist on the Advertised Brand!

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= New G6-Volt TRIN ResElectric ARC WEL S Works Off Any Storage Battery Or Ordinary Light Socket E f This new electric arc welder is made possible by the FOR invention of a low voltage carbon. Auto batteries ; may be used without removing from car. Uses 2 about the same current as four headlight buibs. Z Can be used on electric light socket by using a 42— Trindl converter in place of battery. Broken parts =— are simply melted together by the white hot electric arc, in just a few seconds. Produces about 7,000 degrees heat. HOTTEST FLAME KNOWN Melts iron and steel instantly. Welds fenders, radiators, AGENT Men vee ears to sell holes in bodies, milk cans, tanks, brazes broken castings. ene ene tee eee Payee ae Works on anything—iron, steel, brass, copper, tin or gal- shops, factories, Five-ininute de vanized metal. Permanent repairs made almost for noth- monstration makes sales. UP TO ing. Used by factories in many operations. Positive 150% PROFIT! Write Today! money-back guarantee by a responsible firm. Act now! 7 TRINDL PRODUCTS, 2229-RU CALUMET AVE., CHICAGO, ILL. SE FROUS 7) MARKETS WAITING! NUFOND GIANTS WEIGH x= z UP TO 3 LBS. EACH M gA s Season Just Starting! Frog FRE E Y y legs in big demand at good prices the year round. Millions used yearly! BG OK We have one of the largest Tog markets in the wor rid. Sell to us in addition to Rae other waiting markets. Men & Women starting in every state and Canada! Now’s the time to begin. Small pond starts YOU. FREE BOOK explains unusual offer to beginners. Get this year’s eggs. Write today! American Frog Canning Co. Dept. 119-M New Orleans, La. NEW BRUSH PLATING OUTFITS | |! tor auto parts. Connect to a battery, no tanks used. Almost as simple as painting. Your opportunity to make good income plating auto parts, reflectors, mirrors, ete. Free Particulars and Proofs GUNMETAL co. Ave. P TEA AND COFFEE ROUTES PAYING UP TO $60.00 IN A WEEK — National company needs more men at once te J make regular calls on local routes. No experience needed. Operate on our capital. I give producers brand-new Ford cars as bonus. Rush name on posteard for FREE Facts. ALBERT MILLS 3947 Monmouth Ave., Cincinnati, 0O. Decatur, Til. aca tenn eS AUTOPOWER tells you how in plain, easy, simple, and illustrated instructions ¥ that anyone can follow. Change auto generators into useful, practical A. C. and È D. C. generators and motors with voltage from 2 to 1,000 volts, for power, light, welding, radio, sound, ete. No previous experience nor special tools needed. Generators can be driven by wind, water, fan belt, etc. Already used and endorsed by thousands. Send today ‘for your copy, and also receive FREE a copy of PRACTICAL ELECTRIX, the new publication for the man who wants to KNOW, BUILD, REPAIR and READ about. electrical apparatus and machinery. Book and Magazine postpaid only $1.00. ood AUTOPOWER, Dent. 0, 412 S. Hoyne Ave., Chicago, When Answering Advertisements Please Mention July Modern Mechanix 19

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AN ase CLOG BIG VOLUMES Don’t send us a cent—just your name and address and we ship all of these books to you for ten days free examination. Look them over carefully, see how easy it is to find out the things you want to know, and then decide whether or not you want to keep them. The price and terms are so low that everyone should have them on hand for ready reference. Billions of dollars are being used to make jobs and the Home Modernization Program offers the biggest chance to make money carpenters have ; ever known. Are YOU ready? Can you remodel from start to finish—do you know the tricks of estimating, laying out, ete.? Here’s your chance to get these facts—quickly—easily, without study or work—just put your finger on what you want to know instantly. Carpenters, Architects, Contractors, Home Builders A gold mine of facts can often be converted into a gold s mine of dollars, for builders save money and learn how to make more money With the five big books on architecture, carpentry and building. Carpenters make themselves contractors by learning how to estimate correctly; contractors are able to handle bigger and more profitable jobs by learning how the big fellows do it. Men who want to build homes can save money by learning how it should be done. The new Jiffy Index puts before your eyes without wasted time, the things you want to know. Nothing overlooked. Use of tools, building construc- tion, heating, lighting, plumbing, architectural drawing; all covered. These Drawing Instruments (590°) Included

Value Complete set of drawing instruments if Srael 52 = eames RS you send for these building books NOW, yh SERS KSh N These instruments are made of the finest German silver, are absolutely accurate and are packed in velvet lined leatherette pocket case. Real $10 value, but free to you with these books. American Technical Society, ; Drexel Ave. at 58th St., Oept. GB320, Chicago, III. I would like to look at the five books described above. Send them on your free offer. I will pay the few cents delivery charges only and will examine them thoroughly and return them in ten days unless I like them, in which case I will send you $2.00 and after that $3.00 per menth until the total price of only $19.80 is paid. You are also to send me the drafting instruments and consulting membership eertificate of the American Technical Society, without extra charge.

ISAING sccric meno vanneeeemerie i erenarens owen ec et ec case seco gem tees ago pe AE ADS NT Sg PS ts Address -_ <a ee ee ee ee ee ee ee ee ee “see wee eS Ke Please attach letter stating age, employer’s name and address and that of at least one business man as a reference.

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Page 21

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Send $2 Deposit on radio shown above only Balance C.O.D. plus postage Mo Why pay faney priori for radios? Buy from us and save up to 50%, O88 ya WEER CATALOG FREE ‘guarantee, INO-TIS om iful dels, & to 15 tubes, —money, back if not abso- 7 pears. HOMES and AUTOS: | lutely satisfied. ONE YEAR GUARANTEE WORLD-WIDE RADIO CO., 2868 Elston Ave., Dept. M, Chicago. til. SPECIAL Only elena ncn ana oleate TUOMMRS IRL CVMA Aesth e ELECTRICAL ENGINEERING Oct erect Prepare yourself, at Low Cost, for secure future. Modern course. So simplified anyone can understand quickly. ; RADIO ENGINEERING Extra fine course in radic, public address, : photo-electric work. Trains you to be super-service man, real vacuum tube technician. Experimental kits furnished. Diploma given on completion. Tuition, ONLY $25, either course, Deferred payment plan available. cal neld. E EIl Send name quick for free copies of school catalogs a student magazines, complete details. SEND NOW. 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Page 23

Full size, heavy duty Aladdin Electric ARG WELDER only $359.25 with De Luxe Accessories! Has efficiency of machines costing $145 to $800. ` Wolds all metals and alloys from heavy motor block and castings to fenders and light sheet metal. Also fine for soldering and brazing. Fully guaranteed. Approved by Automotive Test Laboratories. Easily portable on casters. WORKS FROM 110-VSOCKET. Simplyplug into 110-Volt or 220-Volt electric socket— costs only few pennies an hour to use. Has complete heat controls. Anyone can use easily. Full instructions included. AMAZING DETAILS FREE! Write today for sensational facts about Aladdin Are Welder for $39.25 including De Luxe Accessories. COMMONWEALTH MFG. CORP., Dept. X-52 4208 Davis Lane Cincinnati, Ohio erm STRIPE YOUR OWN AUTOMOBILE Anyone can stripe a car with a ROLL- A-STRIPE. You can save the price of your striping job and earn money doing others. Specially knurled roller and aependable gauge. Paint, lacquer, ename or varnish may be used. Stripe signs, furniture, models, etc. See any Duco Dealer today or send direct. Postpaid $1.50. Send for FREE circular on compressors and spray guns. MODCRAFT INDUSTRIES, Dept. D-27, 2908 N. Nordica Ave., Chicago, Ill. AVIATION COURSE FREE: BOYS, GIRLS, MEN, WOMEN ... NATIONAL ATIRMEN'S RESERVE wants members! This non- profit organization is forming flying eseadrilles in all parts of the United States. Join now and receive FREE ground course in aviation . .. official air- men’s identification card . . national lapel emblem. One dollar membership fee starts you Jearning aviation. Send today! NATIONAL AIRMEN’S RESERVE Adams Airport, Box MM, North Hollywood, California AFTERNOONS FREE for life’s pleasures. Drive to the country or go to the “Movies” afternoons. Work each morning till noon at HOME. Unusual Business “Plan” (Treatise No. 1). No Canvassing. Prepare for Surprise! Write now in ' time for a happy summer! NATIONAL FOLIOS-C, Station “D”, Los Angeles. TO GN cee Ai eit Pah wanes S para Tae AS A ANNEN E e= bs Most educational hobby n i Se ee any boy can have! 29 pieces AV NA Ea ort genuine commercial apparatus. Illustrated manual shows how to build radio circuits, 110-volt motor, extension phone, thief detector, are light, are furnace, electric stove, elec. door lock, generate ultra-violet rays. 3 99 AC to DC rectifier, scores more. Value $14. ONLY. a S Rooks Value $4.50, given with kit. Radio-Elec. ~ Short Courses, ete. Complete value $18.50, for only $3.99. Price back if mot pleased. Order now, or get free book! ELECTRICAL SALVAGE CO., Box 524-A44, Lincoln, Nebr. (2 —— ates WX 6 BOONS Wit re ett AY Glecthic OUTBOARD MOTOR| Ideal for boats or canoes. Assures variable speed from standstill to maximum. Operates 8 to 12 hours on 6 valt battery, 12 volt battery doubles the speed and power. Reverse by snap of switeh. No fuss or muss and so simple a child ĉan operate it. You ean use both hands for fishing as special device holds its course. other features make it an ideal motor. Write for complete free details and give dealer’s name, LEJAY MFG. CO. 814 LeJay Building Minneapolis, ie phe ightweight - lean - Silent Minn. Many CITY CARRIERS GOVER JOBS START $1260 to $2100 a Year OVER 42,000 APPOINTMENTS LAST GOVERNMENT YEAR Railway Postal Clerks Railway Postal Clerks get $1,900 the first year regular, being paid on the first and fifteenth of each month. ($79.17 ach pay day.) ‘Their pay is automatically increased yearly to $2,450. Advance may be had to Chief Clerk at $2,700 a ($112.50 each pay day.) year. i UNITED: STATES MATL RAILWAY POST COFFE PERT ee ELL y h EEN f T THE i l oy á f 3 Days On—3 Days Off—Full Pay ree Se Railway Postal Clerks on long runs usually work 3 days and have 3 days off duty or in the same proportion. During this off duty their pay continues just as though they were working. They travel on a pass when on business. 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Page 24

ij A —— eee en PRD Tey aR Peo ~~ 2 W —i oe o -8 E me p E ; == EES- F mm e oe = aS ge |} — |} tk a a ae Be ee E Debra oped =E a =] -a n oe cut aur E peA -W E ELE S] mee UTA —— Å a C SS ee a TEA EN or E mo oo oo on hd — — a BOOKS SENT FREE! ON APPROVAL 5 VOLUMES BRAND NEW EDITION Only 15 minutes a day with these WON- DER BOOKS can prepare you for a good drafting job in less than a year. Mechani- cal and architectural drafting from simple straight lines to important complex plans. A step at a time! Built especially for be- for men with only grammar school- For Beginners Written, so you can wotont hep ginners, l understand every, Yogis ing, Drafting room practice, PLUS EN- oae and architects, GINEERING, made easy and clear. In- DeLuxe flexible binding, cludes complete course in blue-print nearly 2,000 pages, reading. ; 1546 blueprints, charts Big Field Big Demand Big Pay and diagrams; prepares you for a good drafting job in mechanical or architectural lines. Sent for 10 days’ free exami- nation if you mail coupon immediately. These Instrument Included Competent draftsmen are urgently needed right now in all building and manufacturing lines at $30.00 to $75.00 a_week. That’s just the beginning—FOR DRAFTSMEN HAVE THE BEST CHANCES FOR ADVANCEMENT. Pleasant, fascinating work, easy to learn and do. Learn quickly with these hbooks—send coupon for a set and see for yourself. A year’s consulting membership in _the American Technical Society now given to all readers of this famous cyclopedia of drafting. Many say that tt is worth more than the cost of the books. Complete set of drawing instruments if you send for these drafting books NOW. These instruments are made of the finest of German silver, are absolutely accurate and are packed in velvet lined leatherette pocket case. Real $10 value, but included with these books. AMERICAN TECHNICAL SOCIETY Dept. DB320, Drexel at 58th St., Chicago, rie DB320, fil. volume set of drafting. ; fils = o cae m | L =n American Technical Society, Drexel at 58th St., Chicago, Send for 10 days’ trial New 5 | the few cents delivery charges, If I wish, I may return books in 10 days and owe you nothing, but if I decide to keep them, I will send $2.00 after 10 days, then only $3.00 a month until $24.80, the adver- tising price, is paid. Send latest edition and include drawing instru- ments and membership certificate. I will pay Name AdGYeSS. ....--_sssaseun se seen en nee ep a a a Attach letter stating age, occupation, employer’s name and that of at least one business Man as a reference, rROTARY TYPELESS PRINTER Sensational PRINT-O-PRESS DOES WORK $995 Complete Stencil Duplicator. Prints post OF $150 cards and up to 8%x11 letters, MACHINES circulars. Many advance features. Details free. Fully Warranted. Professional Products Dept. 715, Silverton, Ohio HAVE YOU A RADIO IN YOUR CAR? Do you know that the RADIO BUILDERS’ MANUAL describes a fine G-tube auto set? Why not get a copy and build your own? Send 50c today to MODERN MECHANIX PUBL. CO., Fawcett Bldg., Greenwich, Conn. GAS MOTORS FREE finished, Never in the history of gas en- 7 mounte | gines was a motor ever offered Ar ed fly wheel at so low a price. All America us) with every has acciaimed this engineering tri- $ motor! z umph—accomplisned by outstand- ing G. Q. designers and engi- neers after years of exhaustive, scientific, aercdynamic research. Has broken all vecords for amazing per- formance. Flies model planes up to 10 ft. wime'spread. Also used for boats. And look at all these extra features! Easy starting—just a_ twist of the wrist. Steady running—runs 27 minutes on ounce of gas, Precision, replaceable parts. Cylinder and Piston Lapped. Longest erank shaft ever made on miniature motor. Chrome nickel steel shaft with 11%” bearing surface, Connecting rod of high speed bronze. 1⁄5 horse power at 3000 to T7000 R. P.M. This famous motor complete, entirely as- sembled on a stand. Tested and run before shipment— ches ee ponten, No oil, gas or batteries in- d, Only $12.5 sostpaid. One D ice. 3 trated catalog 3c. è ; = Sy Sere Irug G.H.Q. MODEL AIRPLANE CO. 854 East 149th St. Dept. A New York, N.Y. a Accept No Substitutes! Awais ARREST HIM, OFFICER! LL HAVE COMPLETE FACTS ON THE OTHER FELLOW TONIGHT! Secret Service Operator No. 38 is on the job . .. FOLLOW HIM through all the excitement of his chase aft:r the counterfeit gang. Write NOW for F R E Confidential Reports No. 38 Made to His Chief! Tt may open your eyes to the great opportunity for YOU as a well paid Finger Print Expert. The kind of work you'd like. Excitement! Travel! Thrills! A REGULAR MONTHLY salary. REWARD MONEY. Grad- uates of this school HEAD 47% of all Identification Bureaus in U. S,! Write for Free Reports, Finger Print Book, low prices, Easy Terms Offer, if IT or over. Literature will be sent only to persons stating their age. INSTITUTE OF APPLIED SCIENCE 1920 Sunnyside Ave., Dept. B-235 Chicago, Illinois STO CARBON KNOCK Without Removing Cylinder Head PAT. PEND. ELIM-0-NOCK surrressor A MECHANICAL DEVICE, inserted BETWEEN each spark plug and the cylinder head. ELIMINATES CARBON anil VALVE JOBS. STOPS SPARK PLUG FOULING, SAVES GAS and OIL. INCREASES POWER, GIVES ANTI- REGULAR GASOLINE. KNOCK PERFORMANCE on SIMPLE TO INSTALL. LASTS for LIFE of CAR. Ob- tainable direct from us or through your local dealer, Price 35¢ each, at our plant, or mailed to you C.O.D. When or- dering be sure to order one ELIM-O-NOCK for each cylinder, Print name and address plainly, and specify year, model, and make of car. Mail your money order or check to MERCURY MOTOR PRODUCTS CO., Dept. E., 1258 Boylston St., Boston, Mass. Live agents wanted. WHAT STRANGE POWERS Did The Ancients Possess? Wives was the source of knowledge that made it possible for the ancients to perform miracles? These wise men of the past knew the mysteries of life and personal ower. This wisdom is not lost—it is with- held from the masses. It is offered freely TO YOU, if you have an open mind. Write for free sealed book. Address: Scribe D.F.Z. She ROSICRUCIANS San Jose (AMORC) California available at $125-$175 per month, steady. Cabin. Hunt, trap, patrol. Qualify at once. Get details immediately. DRILLS, GRINDS, POLISHES, SHARPENS, SANDS, SAWS, J CARVES — easily, quickly A whole shopful of tools in one. Most sensational value of 1937. sturdy power tool needed by all home owners, mechanics and carpenters. POWERFUL~—SPEEDY—DEPENDABLE 110 volt, A.C.-D.C. Motor. Triple geared for extra power. _ Drills steel, wood, all materials. Univer- sal chuck 14’ capacity. Ball-bearing thrust. Self- enclosed fan. Highest quality workmanship and materials. Uses 50 different accessories, instantly interchangeable, 10-DAY money-back TRIAL. Accessory outfit, including set of FR EE drills, mounted grinder, sanding discs, mandrel, mounted brush, ete., sent free with each WHIZ tool ordered now. Take advantage of this offer. Complete outfit for only $6.95 postpaid. PARAMOUNT PROD. CO., Dept, 8B, 245 Broadway, New York, N. Y. [ustst on the Advertised Brand!

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Help Kidneys Don’t Take Drastic Drugs Your Kidneys contain 9 million tiny tubes or filters which may be endangered by neglect or drastic, irritating drugs. Be careful. If functional Kidney or Bladder disorders make you suffer from Getting Up Nights, Nervousness, Loss of Pep, Leg Pains, Rheumatic Pains, Dizziness, Circles Under tyes, Neuralgia, Acidity, Burning, Smarting or Itching, you don’t need to take chances. All druggists now have the most modern advanced treatment for these troubles—a Doctor’s prescription called Cystex (Siss-Tex). Works fast—safe and sure. In 48 hours it must bring new vitality and is guaranteed to make you feel years younger in one week or money back on return of empty package. Cystex costs only 3c a dose at druggists and the guarantee protects you. HANDY MAN'S HOME MANUAL New 1937 Edition 144 Pages 800 Pictures How To Repair Broken Furniture, The Home Radio Set, The Basement Furnace, Home Plumbing and 1,000 other items for the ailing home. How To Make— All-Steel Auto Trailer, World Wide Radio, Colonial Furniture, Toys and Games, and other interesting home shop projects. Get your copy now at your SO favorite newsstand or order direct from: MODERN MECHANIX PUB. CO. Fawcett Building :: Greenwich, Conn. “ar OMAN TEND AMAZINGLY WAY TO GET INTO |ELECTRICITY Send Today for Details of My “PAY-AFTER-GRADUATION” PLAN Don’t spend your life never sure of a job. Let us prepare you for your start in a good paying field. Let us teach you how to pre- pare for positions that lead to good salaries in Electricity— NOT by correspondence, but by an amazing way we teach right here in the great Coyne Shops you get a practical training in 90 days. Mail the coupon below. If you are short of money I'll send you all detailsof my **pay-after-graduation plan’’ where many get my training first and start paying for it 5 months after they Start school and then have 18 months to complete their payments. LEARN BY DOING=—IN 90 DAYS BY ACTUAL WORK —In the Great Coyne Shops I don’t care if you don’t know an armature from an air brake — I don’t expect you to! Coyne training is practical ‘‘learn-by-doing”’ training. Don’t let lack of money hold you back from getting all de- tails of my amazing plan, MANY EARN WHILE LEARNING If you need part time work to help pay your expenses, we may be able to help you as we have hundreds of others. When you graduate we'll give you lifetime employment service. And, in 12 brief weeks, in the great shops of Coyne, we train you as you never dreamed you could be trained .. . on one of the greatest outlays of electrical apparatus ever assembled .. . real dynamos, engines, power plants, autos, switchboards, housewiring, armature winding and many other branches of Electricity. ELECTRIC REFRIGERATION AIR CONDITIONING Right now we are including additional instruction in Electric Re- frigeration and Air Conditioning without extra cost so that your training will be complete and you can get into this marvelous, rapidly expanding field. GET THE F ACTS Coyne is your great chance to ; get into Electricity. This school is 38 years old — Coyne training is tested. You can find out every- thing absolutely free. Simply mail the coupon and let us send you the big, free Coyne book with photographs ... facts - - ; opportunities. Tells you how many carn expenses while training and how we assist our graduates in the field. No obligation to you. So act at once. Just mail coupon. BIG FREE BOOKS? soon eee absolutely FREE. aee stoy M.E, Pewi gaa a COYNE ELECTRICAL SCHOOL 500 S. PAULINA ST., Dept. B7-$3, CHICAGO, ILL. ee aS aS aa ae eel, AN rT H. C. LEWIS. Pres., COYNE ELECTRICAL SCHOOL i Dept. B7-53 500 S. Paulina St., Chicago, Ill. Dear Mr. Lewis: Without obligation send me your big, free | catalog with facts about Coyne Training and details of your ! ‘““Pay-Tuition-After-Graduation’”’ Plan. NE e eaa oae orans PEE OEE a eao AE o aa aG zi Adress d © 0:0) etes eooeaoowoatooooooaan ooo eoa‘’‘a oou ooooooooo’ o’ *. . i When Answering Advertisements Please Mention July Modern Mechanix ju

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Editor’s Note: > not require special research or involve trade secrets. reply. Address: OPERATING AN AUTO ON DIESEL FUEL Having read much about the conversion of gasoline motors into diesel engines I am wondering whether you could enlighten me, somewhat, on the subject. I own an American-built car, of the six cylinder type, built in 1927. Is it possible to convert this motor into one that will burn diesel fuel and if so, where might I find plans for doing it? —Ivan A. Hughes, Tempe, Australia Several years ago, T. S. Redmond, a Pacific Coast auto- motive engineer, developed a diesel fuel burning car from a standard four cylinder automobile. intended for operation only on gasoline. The construction of this fuel oil attach- ment was described in detail in the 1936 edition of Modern Mechanix’ “How To Build It” along with several other diesel conversion plans. The original Redmond car was designed for operating on both gasoline and erude oil; the motor first being heated by running it on gasoline and then switching over to crude oil. Later a car, operating only on diesel fuel, was designed which involved the use of a special cylinder head. Both of these fuel oil motors can be built by anyone possessing some knowledge of the operation of internal combustion engines. Those desiring copies of the “How To Build It” manual for 1936 can still obtain them from Modern Mechanix Book Dept., Greenwich, Conn., for 50e postpaid. MAKING A GREASE REMOVING HAND SOAP Like many other readers, I enjoy working with machin- ery, but as this is, by no means, a clean pastime, I find it extremely difficult to remove grease from my hands with ordinary soap. I am sure that you know of some formula for making a soap that will remove grease and grime in a hurry and hope that you will pass it along to the many mechanics who read MM.—L. Farkus, Charleroi, Pa. A good quality hand soap that will effectively remove erease and dirt can be made from materials obtainable at your corner drug store. The following formula is suggested: Cocoanut oil, 50 parts; Caustic soda (40° Be’), 25 parts; Powered pumice stone, 50 parts; Lavender oil, 4 part and Caraway oil, 1/10 part. Heat the cocoanut oil until melted and add the caustic soda, stirring it into the oil where the temperature of the solution has reached 90° F. Last, add the powdered pumice stone and the perfumes and stir the mass thoroughly. To prevent evaporation, store the soap in metal containers fitted with friction lids. B ELIMINATOR FOR MM AUTO RADIO I constructed the six tube automobile receiver which 26 Your questions will be answered personally and free of charge by MM experts provided they do Names and addresses of manufacturers of new products de- scribed in this issue can also be obtained free upon reqitest. Problems Editor, Modern Mechanix Publishing Co., 1501 Broadway, New York City. ee $] i mah CEEE UA Cia =. T A m Enclose a self-addressed and stamped envelope for appeared in the “Radio Builders Manual” and secured very satisfactory results, but as this set is several years old, it requires the use of B batteries for supplying plate vol- tages. Do you know where I might obtain plans for a B eliminator of the vibrating armature type which could be used in conjunction with my present receiver so as to bring it up to date?—George W. Eveleigh, Cos Cob, Conn. Readers who constructed the six tube auto set which appeared in the “Radio Builders Manual” can easily build a B battery eliminator so as to dispense with the use of B batteries. A unit that will work well with this set was described in the May 1937 issue of Modern Mechanix in conjunction with the All-Wave Farm Receiver. The B power supply used with the farm set is interchangeable with the MM Auto Radio. By employing a B battery eliminator, only the car’s storage battery is required for supplying current to the receiver. GALVANIZING METAL BOAT FITTINGS Having been unable to secure any practical information on the galvanizing of metal surfaces, I am wondering whether you could supply any helpful suggestions? I am building one of the MM boats, as described in your blue- print catalog and wish to chemically treat the metal fittings so as to reduce corrosion as much as possible. Is there any method whereby metal can be treated in this manner without the use of elaborate equipment? — George E. Smart, Toronto, Ont., Canada. Iron can be chemically treated so as to provide an effec- tive galvanized surface that will reduce, considerably, cor- rosion produced by salt water. Application of the chemical solution requires only the use of a cheap paint brush; the solution being applied to the metal surface in liberal quantities and allowed to react for 24 hours. To make the galvanizing solution, mix 1 ounce nitrate of copper; 1 ounce sal ammoniac, dissolved in 2 quarts of soft water and 1 ounce of commercial hydrochloric acid in an earthenware vessel. Do not mix these chemicals in a metal container as the reaction of the chemicals on the metal will render the solution useless. After the chemical has been allowed sufficient time to react on the boat fittings, a coat of marine paint or varnish applied over the galvanized metal will further aid in pre- venting corrosion. MOULDING NOVELTIES WITH PAPIER MACHE T am desirous of obtaining some information relative to the making of papier mache novelties. Can you furnish me with information regarding the making of the papier mache, [Continued on page 28]

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Locomotive Has Metal "Ears” PEEDS in excess of 120 m.p.h. are claimed for a new type streamlined locomotive constructed by a leading French railroad. In addition to the usual streamlining, the huge locomotive features two protruding “ears” at its front end which tend to create the visual impression of some prehistoric monster as it hurtles over the rails. The “ears” are made of metal and can be manipulated from the control cab, their purpose being to deflect the air at different angles along the locomotive’s body as a pick-up in speed is achieved. Metal “Bug” Bores Mines NEW mining machine, which theo- -& retically could bore a hole to the center of the earth, has been developed. The device operates in the manner of a burrowing insect and in California tests bored to a depth of 1,125 feet through dirt and hard rock forma- tions. The “bug” is made of metal and has 15- foot jaws. The body of the device houses an electric motor, while screw jack legs are used to hold it in position against the sides of the hole being drilled. The jaws of the machine consist of an empty barrel-shaped device, the edges of which are fitted with teeth that cut in a circular track as the jaw is revolved by a drive from an engine. The empty barrel receives the loosened rock and dirt debris and upon be- coming filled is detached and hoisted out of the hole by means of a cable arrangement. The machine drills a hole large enough to accommodate a crew of men in an elevator. ANNED HEAT 4 © ‘Or Ny È CONTEST CASH _ PRIZES Ist Prize, 50 $2 Bills ($100) 2nd Prize, 50 $1 Bills ($50) 3rd Prize, 50 Half-Dollars ($25) 4th Prize, 50 Quarters ($12.50) Sth to 50th Prizes, 50 Dimes ($5 each prize) IT’S EASY Just answer this one question: “What one event has contributed most to American prosperity in the last 50 years (the period during which the Sterno Cor- poration has been in business)?” OUR answer might be “‘The invention of the automo- bile,” or any one of hundreds of other events. Put reasons in not over 100 words. Send entry with one STERNO label or facsimile, and dealer’s name and address. DEALERS: There’s at least $5 for you (or your clerks) if your customer wins on entry blank you signed. Display Sterno during the contest. Explain conditions relating to it. Enter the contest and win a prize yourself. FOLLOW THESE RULES 1. Anyone except STERNO employees may enter. 2. Write on STERNO GOLDEN JUBILEE PRIZE CONTEST blank (ask your dealer for one) or on a plain sheet of paper: (a) What you consider to be the event that has done most to contribute to the prosperity of America during the past fifty years (the period during which the Sterno Corporation has been in business) and (b) give reasons for your choice in not more than roo words. Literary style isn’t important — awards will be based on the merit of your reasons. 3. All entries must be accompanied by label or facsimile. 4. In case of tie, duplicate prizes will be awarded. Judges’ decisions are to be final. 5. All entries must be postmarked not later than September 30, 1937. STYLE No. 25 RETAIL Price 50¢ IN U. S. For sale at Your Regular Dealer Sterno Canned Heat is smokeless, odorless. Ignites instantly. Safe, clean, can’t spill. The convenient fuel for cooking light meals, warm- ing baby’s bottle, heating water for shavings. Use it for picnics, camp- ing; on yachts and trailers. MAIL YOUR ENTRY TODAY TO DEPT. MM-7 STERNO INSTITUTE 9 East 37th Street, New York, N. Y. When Answering Advertisements Please Mention July Modern Mechanix 27

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| i | + —ss- on approval. Just mail the coupon and we'll send you a set of these remarkable auto books, just off the press. Whether you are a mechanic or helper, ex- pert or apprentice, auto owner or driver, if you’re interested in knowing all about automobile mechanics, take advantage of this FREE OFFER. Nearly 100 pages on DIESEL Engines A better job—in the gigantic auto in- dustry. BIGGER PAY—a chance to go into business for yourself and get a share of the huge profits, are waiting for any man who even half tries to improve himself. Learn auto engineering with these wonder books a new way—without studying or memorizing. Simply use the JIFFY IN- DEX to look up the answer to any auto Built by eleven of America’s CAN YOU FIX IT: These wonder books tell step by step HOW to take out ‘‘play’’ in dif- ferential — to kill the shimmy in steering—to set TIMING—how to put your finger Instantly on engine trouble and then the quick expert way to FIX it. Newest im- Problem. i E ; provements fully cov- greatest automobile engineers, and written ered. Equaltoacomplete jn simple language so you ean understand trade course at less than it a fourth the cost. it. 6 G VOLUMES Brand New Edition 2500 pages, 2000 illus- trations, wiring dia- grams, ete., including Marine Engines, Avia- tion Motors, Diesel en- gines, etc. De Luxe edi- Very newest cars, all covered. FREE! Send NOW and we will in- clude FREE an extra loose-leaf volume No. 7 with newest cars and diagrams and also that famous book ‘‘Automo- bile Service Shop Management." AMERICAN TECHNICAL SOCIETY tion, gold-stamped fiex- DrexelAvenue & 58th St., Dept. AB320, Chicago, II. ible. binding. AMERICAN TECHNICAL SOCIETY, Drexel Ave, & 58th St., Dept. AB320, Chicago, Ill. I would like to see the new 6-volume edition of your AUTO BOOKS. I will pay the few cents delivery charges only, but if I choose to, I may return them express collect. If after 10 days use I prefer to keep them, I will send you $2 and pay the balance at the rate of only $3 a month, until $24.80 is paid. Please inelude free consulting membership and the two extra books as per your offer above. INSSIOWE Seat aoe see oe LU a Address City ee ee em ee ee ee ee ee ee ee Attach letter stating age, ployer and that of at least one business man as reference. HAVE YOU SOME SPARE ROOM ‘a basement or garage where you can do light work? We ean offer you a profitable proposition for 1937 casting new 5 and 10c Novelties, Ashtrays, Toy Automobiles, ete., as Manufacturer for firm of Many years standing. No experience necessary and small outlay starts you. If interested in devoting your spare or full time to profitable work write AT ONCE as we are now closing arrangements for Supply cf our goods. METAL CAST PRODUCTS CO. 1696 Boston Road, New York, N. Y. BE A POULTRY EXPERT Make $1000 to $2500 a Year Free book shows how to get started quickly. You'll be surprised at the amazing profit opportunities in the poultry business. Wherever you live—whatever you do—it is easy to start on a spare or full time basis. Free book tells all. Send for “How to Raise Poultry for Profit.” Learn at home in spare time. The famous N. P. I. home- study course is endorsed by colleges and leading poultrymen, Know how to get the maximum profits from interesting, healthy work. Iron- clad agreement protects you. We have prepared hundreds for good jobs and businesses of their own. Write now for free book. No obligation. National Poultry Institute, Inc., Dept. 131-C, Adams Center, N. Y. Dept. 2, Does many jobs speedily, easily—grinds, drills, engraves, sharpens, routs, carves, polishes, ete. Universal motor—about 20,000 R.P.M.—plugs in any light socket A. C. or D. C. Handles as lightly as a pencil. Weighs only 6 oz., yet is amazingly powerful. Oilless — self-aligning — ball thrust hearings. TEN DAY TRIAL. Satisfaction guaranteed or money back. 20 pe. general utility tool set $5.75 extra, Send for FREE BOOKLET. DREMEL MFG. CO., Dept. 1019-CT, Racine, Wis. 28 Problems [Continued from page 26] itself. Can this compound be made in the home workshop and if so, how?——H. F. Schollion, Panama City, Florida. Papier mache can be formulated in the home workshop from common household ingredients. A moulding material that should well meet your requirements is made as follows: Secure several sheets of old newspaper, cut it into small pieces and boil in water until it becomes a tacky mass, then squeeze out the water. Next, place the pulp in a bowl and add 4 tablespoonfuls of hot glue, mixing it well into the paper in gradual quantities and at the same time adding plaster of Paris until 8 ounces have been mixed into the mass. As the compound has a tendency to dry out quickly it will be necessary to mould the novelties at once. The papier mache, though, can be kept in a workable condition by wrapping it in a damp cloth and storing in an airtight metal container. INSTALLING BRAKES ON AUTO TRAILER I have, just recently, completed the building of “Aloha”, the 14!⁄2-foot house trailer which was described in a past issue of Modern Mechanix. Since the original plans listed brakes as optional equipment and gave no details regard- ing their installation, I would like to know where I might secure some information regarding trailer brakes and in- structions for installing them. Has any trailer brake data been compiled by Modern Mechanix? If so, will you tell me in what issue or issues it appeared ?—David Lurring, Akron, Ohio. Aloha, as well as all other Modern Mechanix trailers, can þe equipped with brakes. Either mechanical or vacuum brakes can be installed in Aloha; both will perform well if care is exercised during the installation. Many trailer builders are under the impression that only the front axle assembly, salvaged from a wrecked car, can be used for the running gear of a trailer, but this is, by no means, correct. The rear-end assembly, obtainable from any car wrecking yard, will provide the trailer builder with the necessary materials for building a sturdy running gear that is already provided with the necessary braking mecha- nisms. By connecting a cable control between the car brakes and those of the trailer an effective braking system, which will stand up under the most severe conditions, will result. Complete instructions for trailer brake installa- tions of both the vacuum and mechanical types will be found in the new MM manual, “How To Build Trailers’, which is available fron’ Modern Mechanix Book Dept., Greenwich, Conn., at 50c. HOW TO TINT WOOD VENEERS In a past issue of Modern Mechanix there appeared an interesting article on wood inlays. As I am quite some distance from the city, I have not been able to secure colored inlay wood. Is it possible for me to stain or dye natural wood inlay material to the particular shades re- quired. If so, what method should be employed in coloring the natural wood veneering?—Roland Gustwhite, Cape Charles, Va. If you have been unsuccessful in securing colored veneer- ing for inlay work, you can tint the natural wood to any desired color with ordinary liquid egg dyes. These dyes can be purchased in packages of six bottles, each containing a different color, from your local druggist or grocery store. The dyes can be applied to the wood with a cotton swab until the correct color shade is obtained. Since the dyes contain an alcoholic solvent, they will dry almost im- mediately after being applied. Accept No Substitutes! Always Insist on the Advertised Brand!

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SPORTSMEN'S Manual — —NEW 1937 EDITION— No sportsman should | | ~~ eS be without a copy of this | . = all-new edition of the Sportsmen’s Manual. If you hunt, fish, camp or indulge in other outdoor sports you will find in it numerous articles to meet your particular fancy. In addition to its many out- door features the new 1937 edition contains | RESERVE YOUR COPY NOW complete plans for building two sportsmen’s trailers, two boats and many kinks and short cuts for the outdoor man. AT YOUR LOCAL NEWS- STAND OR ORDER DIRECT 250 PICTURES MODERN MECHANIX PUBL. CO. Fawcett Building Greerwich, Conn. When Answering Advertisements Please Mention July Modern Mechanix 29

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Mn Acting as motorman for the miniature North Jersey Railroad located in the yard of his Yonkers, N. Y., home, E. J. Quinby presses the “dead man’s button” of the controller, yanks the handle a notch or two and speeds the train on its way. The controller was salvaged from a real car. Right—The model terminal of the “system” pro- vides utmost realism. HAT automatic block signaling system, devoid of switches, relays and elaborate circuits, looked mighty good on paper. In fact, it seemed too good to be true. Surely somebody must have thought of it before. Unable to demonstrate his signaling system on a regular railroad, E. J. Quinby, of Yonkers, N. Y., did the next best thing. He built 4 model electric road in his own back yard. For utmost realism, he actually copied an interurban electric line even to the last detail. The block signaling system was installed, demonstrated, patented. A lead- ing company secured the patents and today the signaling system is acknowledged to be the simplest and most practical of any. It must have been tried. But where was the hitch? Modern Mechanix

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The “crack flier’? of the line enters the prize section of the layout. Note the neatly strung overhead powet wire, the care- fully graded right-of-way, the trestle, and the natural topog- raphy. Left—A touch of the Gay Nineties is afforded by the line’s open trolley car, which is operated by a worm gear motor- drive. Note the “cow catcher”. Meanwhile, this man boasts of one of the country’s outstanding electric miniature railroads. Wearing his good old motorman’s cap and gloves, with one hand resting firmly on the “dead man’s button” of the controller handle and both eyes glued to the track ahead, Quinby dashes along with his electric trains over a most picturesque interurban route. Tunnels, bridges, trestles, cuts, fields, hills and dales—all offer the thrills of a high-speed trolley line. Little banjo- | type block signals flash red or green as their blocks are occupied or cleared. Yet it’s just make believe. For aside from the real full- sized controller at which he sits, this engineer is riding his miniature trains purely in spirit, since the little cars he controls over his back July, 1937 he whens

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The photo at left shows ¢ told No. yi the only locomotive on the line. With a polarized relay in its cab, this locomo- tive can be reversed from the ` remote, stationary controller. s Note realistic trestle. Operating the trains with the skill of an old-timer, Jackie Quinby (left) is the most envied boy in the neighborhood when he runs his father’s miniature rail- road. Circle—Teols, insulators, etc., are stored jn concrete huts along the right-of-way. EINEAN I Local boys vie for the honor of being appointed members of a maintenance crew so they can operate the miniature work train shown above. The coveted “Prize. Section’? award goes to the crew doing the best work each month. “A smn

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Dental Office On Wheels Visits Outlying COMPLETE dental office housed in a specially built bus is being used by Dr. Free- man L. Blunt of Albert Lea, Minn., to aid toothache sufferers living in outlying communities in the southern part of the state. The twenty-five-foot office was built on a one-and-a-half-ton truck chassis and all the features of a permanent office, with hot and cold running water, were perma- nently installed. Dr. Blunt, with an assistant, fol- lows a regular schedule of twice- weekly visits to five villages of Freeborn County, none of which has a resident dentist. The spacious interior was de- signed to please the eye of the patient. Paneled walls of mason- ite are oyster white in the labora- tory and operating room, while the waiting room is done in a rest- ful silver green satin finish. Lino- leum used throughout is in Span- ish red, with woodwork matching walls. New Bottles Can Be Stacked William Fehr is shown holding two of his “stackie” bottles. The hollow bottom makes it possible to stand one on top of the other. At the right is shown a large pile of the bottles. owns Dr. Blunt is shown with his unique dental office on wheels which is used to pay bi-weekly calis to outlying towns without resident dentists. Top photo shows interior of the office. NEW bottle, called the “Stackie,” has been invented by William Fehr of Sac- ramento, Calif., making it possible to stand one bottle on top of another. Holding twelve ounces, the bottom is shaped so that the crown capped neck of another bottle will fit into the hollow and allow the bottom of one bottle to fit onto the shoulder of another. A ridge on the shoulder keeps them from slipping. The design is said to open new merchandis- ing possibilities, being adaptable to mass dis- plays where bottles are stacked one on top of another to form various types of displays and designs. For shipping, approximately forty per cent less space is required. Smithsonian Gets 1902 Car O THE Smithsonian Institution’s collec- tion of historic automobiles has been added the first Franklin car that chugged away from the plant’s gates in 1902. This car, pioneer of a long line of air-cooled autos, was in service until 1916. 33

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License Spells Car Owner's Name Nic Sprank Offers $5.00 For Best Oddity

CAR LICENSE SPELLS NAME/-OLE |) LEE,OF BADGERMINN., HAS THE oo a =; o UNIQUE DISTINCTION OF HAVING AN E =: — — AUTOMOBILE LICENSE WHICH WHEN GT gh res -VIEWED UPSIDE DOWN, SPELL HIS NAME. -Milton Waldron, Nopewing, Mina. 5 = n OO

REW YORK CITY A MINERAL MINE 7- BESIDE BEING THE LARGEST CITY IN THE UNITED STATES, NEW YORK HAS THE ADDED DISTINCTION OF BEING BUILT ON THE BEST MINERAL LOCALITY IN THE UNITED STATES. ALTHOUGH d. 175 MINERALS ARE LOCATED IN THE EARTH OF MANHATTAN ISLAND. GARNETS HAVE BEEN FOUND AT BROADWAY AND 651! ST. OPALS AT 65TH AND 66 HSTREETS AND TOPAZES HAVE BEEN FOUND AT 164 1H STREET AND ST.NICHOLAS AVE. Aifrg Berm, MI. a E238 EN MONUMENT TO CHICKE NS/ RHODE ISLAND REDS ARE BELIEVED TO BE THE ONLY CHICKENS IN THE WORLD TO WHICH AMONUMENT HAS BEEN ERECTED. THIS UNUSUAL MONUMENT IS LOCATED IN LITTLE COMPTON,RI., ORIGIN OF THERHODE ISLAND RED BREED.— Laul Bergeret, (xiral Flis Rode lsiand.

E i

eon

hare so? : IG scat Wor. hs WHAT IS BELIEVED TO BE A RECORD nese aE D BUNCH OF PEARS ON ONE STALK WAS Z IA GROWN BY JOHN MALAN OF CAPETOWN, SOUTH AFRICA.THE MATCH BOX SHOWN FOR —, COMPARISON, INDICATES THE SIZE OF THE FRUIT. wee: - —A. Gordo Lee, Cape lown, South Atria. Five dollars will be paid for the oddity used by Nic Sprank as his central illustration. One dollar will be paid for all others used on this page. Send your oddity to Nic Sprank, Modern Mechanix Publishing Company, 1501 Broadway, New York, N. Y. Source ot proof of each oddity must be given. Send all oddities separately, not with other manuscripts or letters. 34

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World s Largest Switch ee See y" Wit Ui “ee These giant circuit breakers in the switchyard at Boulder Dam deaden the flash when the circuit is broken on the 287.500-volt. 1,200-ampere line carrying power to Los Angeles, 250 miles away.

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Petts Ari EXPOSING The fiagi i p ne f) "a e y Eg x 2 y Fa y # * -f : H Pi mp mM 3 : : z tye = Beery Shy ot plea T > i è E ina orie ea OT avri N sass i oe? MA AA Bee DERS o Collectors with money to spend find counterfeiters ready to meet demand for all “copies” needed. ECRET SERVICE sleuths, working on a private tip-off, recently achieved a sensational “snatch” in New York City. In an out- of-the-way office, on a back street, they located headquarters of a gang dealing in counterfeit and stolen stamps. Elaborate by | manufacturing paraphernalia was seized, including en- } rela : sta graving gadgets, perforation machines, coloring apparatus J ames N ‘ | and various kinds of gum. Miller | | Federal officials, after a laboratory study of some of the newly made stamps, of the current two-cent variety, declared they were about the best ever faked. Had it not been for the vigilance of Uncle Sam’s undercover men, the nation might now be flooded with the spurious stickers. Almost simultaneously with this important discovery, police in Barcelona, Spain, arrested two gangs dealing exten- sively in bogus postage stamps. They had been imitating the widely L. Stewart Barr trying out one of his newest inventions, a self- illuminating magnify- ing glass. This device is useful for detecting forged, repaired or otherwise ‘‘fixed up” stamps. It has its own battery and may be carried in the pocket.

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9TAMP Counterteiters used Spanish 30-centime issue so adeptly that the government found it necessary to with- draw the real stamps from use and to manu- facture, in their place, a new kind of en- graved variety. Just how widespread is the counterfeiting of stamps, not only of the “rare” issues but of the current varieties? And what protec- tion, if any, has the average collector against illegal imitations? These questions may now be answered, for readers of MODERN MECHANIX by two outstanding world authorities: H. A. Robinette, Washington dealer, and L. Stewart | Barr, collector and resident of the nation’s nee capital. In days gone by, dealers did not iia es want to own a single counterfeit. But Mr. Robinette has developed his collec- tion of bogus varieties to one of the largest in the world, so he can have Right—Mr. Barr ex- amining damaged copies. A micrometer and compass are shown at his right. Upper tight——Examining some fake Confederate stamps. At bottom of the page is seen a group of forged stamps. At extreme left, on the opposite page, is the only gen- uine stamp in the group.

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a measuring stick for good and bad stamps offered for sale either to himself or his friends, As for Mr. Barr, he has spent a consider- able portion of his past twelve years of extensive travel in studying counterfeit stamps in every section of the world. Today he probably knows as much about bogus European varieties as any American. First of all, Mr. Robinette points out a revolutionary development in philatelic circles: Not long ago the Treasury Department de- cided that it is legal to illustrate the stamps of dead governments. In other words, the postal issues of all defunct nations or states may now be reproduced without risk of con- flict with the law. “Approximately 130 stamp-issuing nations and colonies of the past are affected, in- cluding: the German Empire, the Russian Empire, the former kingdom of Hungary, Portugal and Spain, the Spanish regimes in Cuba and the Philippines prior to 1898, and the erstwhile empires of Brazil and Mexico. Above——A device invented by Mr. Barr for detecting frauds. It is a very powerful, self-illuminating microscope holding its own battery. This device magnifies stamps 30 times and has already proved its efficiency by reveal- ing counterfeits which otherwise would have been extremely difficult to detect even by the most expert philatelist. “As most collectors already know, there is a strict American law forbidding the illus- trating of all stamps of present-day national governments. Certainly the ruling is a good one. It has prevented the manufacture of counterfeits which would have flooded the philatelic markets and hurt philately as a recreation, a cultural study and a business. “However, now that the statute has been liberalized by the Treasury Department, col- lectors will have to be on guard against frauds and fakes as never before in a genera- tion.” Japanese stamps are counterfeited most prolifically of any in the world, Mr. Robinette says. Particularly is this true of the early issues, of the period between 1871 and 1875, when most of the Nipponese stamps were ornamented with dragons and chrysanthe- mums. Today the finest genuine varieties of this group catalogue up to $100 apiece. Numerically speaking, Swiss counterfeits run a pretty close second to the Japanese fakes, claims Robinette. Next in order come [Continued on page 120] Below — Illustrating methods of stamp counterfeiting. By deft maneuvers with pen and ink, the dishonest “expert” can fake can- cellations, and with the help of water colors, he can fake almost every color known. Some of these changed stamps are almost per- fect reproductions.

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Six-foot Ship Model Features Radio MINIATURE radio op- erated ocean liner that can be controlled within a one-mile radius by its “skipper” on shore has been constructed by Felix La Vallee, of Hugo, Minn. The Radio Lady, as the ship model is named, operates on five- meter ultra-short waves, and twelve different controlling op- erations can be performed. A selector switch and a time relay inside the ship make the elec- tric contacts that cause the ship to respond to the control signals transmitted from the shore. The ship model is six feet long, with an 1ll-inch beam, and weighs about 100 pounds with batteries and radio equip- ment installed. The hull, of glued and doweled wood layers, is divided into water-tight compartments that hold the various units of the controlling ap- paratus and other operating mechanism. Kinetic Energy Motor A KINETIC energy motor developed for marine use has only four working parts —three valves and a rotor. The rotor has four vanes which act as pistons and the valves perform the work of cylinder heads. Steam admitted through an inlet port passes into a space automatically opened by the timed action of a valve. As the valve turns, the steam expands and pushes a vane, propelling the rotor shaft, after which the steam escapes through an exhaust port. Twelve impulse strokes per revolution are imparted by the motor which is claimed to be the most efficient of its type. ces 1

-pi - aens eTe A ER AADS 1 : é Ky Geren Fh rT Te Maximum power at low speed is available with this kinetic energy motor, shown covered and uncovered. Steam entering through an inlet port activates the vanes of the rotor, moving its shaft, to which a propeller can be attached.

ka ot. AS ae t 1: Sad T a ` ESTERS Fog aie Controlled by radio, this ship model built by Felix La Vallee executes 12 differ- ent operations, such as turning, reversing, moving forward at quarter, half, or full speed, tooting a whistle, and turning navigation lights on or off. Radio Bares Oil Line Taps NOVEL radio tap-finder system patented by J. D. Munton and William O. Reeves and assigned to a leading oil producing firm enables pipe line inspectors to detect illegal underground taps no matter how cleverly they are concealed from the human eye. The. system is expected to reduce the “bootleg- ging” of oil from isolated sections of the buried pipe lines which lead from the oil fields to distant refineries. The system sets up electrical oscillations in the pipe line, forming an electric field which has a characteristic pattern if the pipe line runs along without side taps. Inspectors walk above the buried pipe wearing ear- phones connected to a radio detector device which is activated by the pipe line signals. When a buried tap is reached, a warning hum is heard in the earphones. Auxiliary instruments, more ac- curate than the audible signal de- vice, are then used to tell roughly the size of the buried object caus- ing the hum. The inspectors quickly learn to tell the exact point where an illegal tap-off has been made, eliminating the former expense incurred by the oil com- panies in sending out crews to dig at points where taps were falsely believed to have been made by the oil bootleggers. 39

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a D e a ee ee ee “Heart Operation Performed on/R Above——Roach with heart exposed after oper- ation. Heart is fastened to a glass needle by a single hair. Bright light thrown across the needle casts a shadow on the film, thereby showing each pulse as heatt moves needle. Above, right—Another view of the delicate n — surgical operation. Dr. J. Franklin Yeager TRANGER and more precise than any- is shown anesthetizing the roach just before thine of the sort ever attempted before its heart throbs are recorded. Below— d i i Prints of the heart beats telling a story was the surgical operation recently per- never before revealed to medical science. formed in Washington on a lowly cockroach. With an ultra-sensitive instrument called the “mechanocardiograph,” Dr. J. Franklin Yeager, Department of Agriculture ento- mologist, recorded the heart-throbs of the insect and for the first time in history re- corded their every movement. The idea was to get at the fundamental facts of insect heart action to help man in his never-ending efforts to outwit the millions of bugs that cost the nation billions of dollars annually in de- stroyed fruits, vegetables and trees. Dr. Yeager’s instruments, procedure and results were unlike anything hitherto known. The first of his many delicate tasks was a surgical maneuver. He put a bit of anes- thetic on the cockroach, cut open its body so the heart was exposed, and pinned down the [Continued on page 131] 40 Modern Mechanix T = Liles À l . l git a £ 7 p i-a LUE J S hi | eer ee aiana ne eet bees ba ms Fes tN a a k o e E

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Ea special chassis featuring a Ford Midget Streamlined “Locomotive” Thrills Crowds HILDREN and grown-ups alike are thrilled by a ride in a miniature excursion train at Seaside Beach, Md., which is pulled by a midget streamlined ‘“Jocomotive.” Pulling a string of open observation cars, the stream- liner shuttles back and forth over the heads of bathers in the water below a half-mile long pier. The “locomotive” consists of a auto engine and covered with a body resembling a Union Pacific streamlined engine. The train’s wheels are guided by a narrow- gauge track. Apparatus Detects Gases C ed Bae ee a or wr a Oe eee ad Developed by M. Kling in the chemical laboratory of the Paris (France) Police Department, this apparatus detects presence of poisonous gases by discoloration of liquids. N APPARATUS for detecting the pres- ence of poisonous gases by registering the discoloration of special liquids placed within its chambers has been developed by M. Kling, director of the chemical laboratory maintained by the Paris (France) Police De- partment. Conversely, the apparatus indi- cates when danger has passed. July, 1937 This miniature Union Pacific streamlined “locomotive” is powered by a Ford automobile engine. It pulls a train of observation cars over a half-mile pier at a Maryland beach. ee Model Steamship Functions PRACTICAL miniature steamboat has been constructed from scrap metal parts by James Pierce, a power plant engineer of Milwaukee, Wis. The hand-made model has an alcohol lamp which heats water in a small boiler to provide the steam power for motivating the boat. The steam is run into alternating triple pistons which drive a shaft connected to paddle wheels on each side of the model. Tests have proved that the boat can travel quite some distance before it is necessary to refuel. The craft is four feet long, nine inches wide amidship, and weighs eighteen pounds. The model’s design resembles that of large boats now in general use. Built from scrap metal parts by James Pierce, of Milwaukee, Wis., this model steamboat has a steam engine that enables it to travel short distances on a very small amount of fuel. 4] oe NA

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Ree. e eh ane i se i KOS ix ae ghai ma i T, er. ae wea P REY =» = Taeng by Benn Hal MERICA spends more than $5,000,000 each year to ex- press, by means of colorful and noisy fireworks her patriotic and religious fervor. It’s a neat little business, the B pyrotechnic industry, and has grown tremendously since prehistoric man dabbled in his mute way with the wonder of fire and the fury of sound. It has expanded, too, since that more modern occasion in the 13th century when gunpowder was given to the world and changed history—and methods of celebrating those historical changes. The industry of fireworks grew with leaps and bounds through the 17th, 18th and 19th centuries and today it is an international trade, with its manufacturers, workers, op- ponents, bootleggers, sweatshops and all that is part and parcel of the American industrial scene. Fireworks manufacturing has developed, in its own spe- cialized fashion, into a luxury business. The way to celebrate 42 less Rade! ¥ a | à i i ks i r i Aji Tr sd w ue 2) . o tua w Seat bies plat S a Š i ina ainmin A ala Yo a aa a aa oa da a" a ddaa ta aia ne aii ae i oaeoi anaa aiai i pe ie ae Fa E = Cie

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America’s freedom and her religious feast days is to ignite little, cylindrical red stubs or to light longer, fused affairs which dart through the air with great speed and con- siderable ease. It isn’t utterly essential, of course, that we celebrate thusly, but it is a tradition, and traditions have a way of per- sisting. Hence the fireworks manufacturers are nicely established, although they are thought of only once or twice every year. The patriotic or religious display of fire- works, with its booms, smells, sky pictures and appeal, is a peace-time symbol of the battlefield—the child’s way of viewing war —some of the thrills, noise and flashes and little of the danger of actual bloody combat. It isn’t altogether a realistic picture, if one is to see the thing through, but it possesses Americans pay more than $5,000,000 annual- ly to express patriotic and religious fervor. the appeal of the parade, if not of the casualty list. America has, of course, no monopoly on the celebrating of holidays with fireworks. China and Japan use them for many oc- casions; France on Bastille Day; England on Guy Fawkes Day. Most other European and Latin American countries have their holidays when fireworks are in demand. Not all the fireworks sold in the United States in 1936 was bought to amuse Junior. About fifty per cent of the sales was to in- dustrial and governmental bureaus. The Opposite page (circle)-—A July 14th celebra tion in France known as “Bastille Day.’ Fire works are used to celebrate the fall of the Bastille very much in the same manner as the; are used in the U. S. to celebrate July 4th. Above——Here is a large aerial display showing the various levels at which different pieces “open.” Left—A worker preparing the dis- play which, when ignited, will produce a large palin tree effect.

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flares and signal lights used at sea and for military signaling and aeroplane use are all part of the pyrotechnic industry—half of it, in fact. The United States government conducts a “fireworks college’ in Washington, D. C., where bombs, flares and other military de- vices are studied. That American fairyland, Hollywood, consumes a share of the firework output. Movieland needs pyrotechnics for effects in battles and explosions, and uses smoke bombs for artificial blazes. And fireworks are used for sham battles. There is the yarn told of a Central American general who faced a revolution. He is said to have ordered several cases of fireworks and to have frightened off skittish revolu- tionists with them. The trade calls about forty-five per cent of its sales “commercial”; that is, the goods John J. Public buys for his children—and for his own fun. This buying is seasonal. Part of the sales, five per cent or so, is known as “display” sales—goods sold to amusement parks, fairs, municipalities for celebrating the Fourth and other occasions. Many amuse- ment parks have found it a paying policy to devote part of one evening each week to a fireworks display. Several state fairs have reported increased attendance because of nightly showings of fireworks. Such large- scale exhibits include eye-dazzling spectacles —much more than mere noise for noise’s sake. The sky serves as a stage background for elaborate displays of rockets, candles and more complex displays. It is possible that if the Dionne lassies were “done in pyrotech- nics” they would possess far greater “human appeal” than any other display! Several cities that have banned the sale of fireworks have taken it upon themselves to furnish their taxpayers with safer displays, handled by experts. Milwaukee is one city which has done so. The “commercial” or public trade is divided into two seasons. The Fourth of July is cele- brated in the north and in most other sections of the country with fireworks. But in -the south it is Christmas that is celebrated with pyrotechnic outbursts. The reason for the southland doing this is not clear. Evidently several factors are involved. The intense July heat may discourage the added heat wave generated by fireworks. And it may Below——Fireworks dried in the sun are more effec- tive than those dried by other means. Manufac- turers employ extreme caution to prevent acci- dents. Each worker or group of workers is kept separate from the rest.

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ele ot be that the Fourth of July is, to some southerners, some- thing of a lesser holiday, that is, compared to the way in which it is celebrated in the northe When there is snow on the ground, the spectacle of the colored displays against a white blanket is a gorgeous pageant that the northern Fourth lacks. In any event, it suits the manufacturers and gives them two seasons, just like the makers of clothes and other commodities. “Commercial” fireworks may be grouped into five gen- eral classes with various subdivisions. These five are: (A) Firecrackers—the most popular. (B) Roman can- dles which discharge flaming colored balls or stars or both. Salts of various metals are used for coler—barium for green, aluminum for white, copper for blue and strontium for red. (C) Skyrockets are very popular. At one end is a cap and at the other a stick to stabilize the Hight to the heavens. The tube itself is filled with a rapidly-burning composition in which are mingled the stars or pellets. A composition of quick and slow burning powder is packed in very lightly. A fuse runs down a hole through the length of the powder.’ When ignited, the fuse fires the powder. Gases are generated and the rocket is propelled into the air. At its hight, the explosive powders are ignited and the stars and serpents and other objects fly in all directions. (D) Pinwheels. Spitting fire rotates a burning wheel supported by a central pin. (E) Set pieces which give showers of colored sparks or flames or form pictures of fire in the air. Pictures over 600 feet long and 50 feet Right—A striking view of the tall, thin spire of the Washington Monument. illuminated by the glare of bursting bombs and fiery steamers, that climaxed the observance on the 156th anniversary of the signing of the Declaration of Independence.

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high have been produced at Crystal Palace, London, where set pieces have been highly developed. The material for fireworks — gunpowder and other ingredients — is purchased from various manufacturers and then mixed by the pyrotechnic manufacturers. Discoveries and inventions made within the past two hundred Left—One of the last

Je te egal AR Kane

i P steps in manufacture of $37 | rockets. In one of ; $ many small buildings à eee comprising the plant, ea =a worker fills the card- board tube with various figi nee =, - k ifi TIR wii yey m aag “ i y . . Shits she's iS =a it, s 1 & i NN y rx $ types of powder neces- sary for obtaining de- sired effect. Extreme caution is used in the handling of material. ar Below—Climax of a monstrous display. A battleship outlined by fire forms major part of the spectacle. Care- fully constructed bombs and flares are responsi- ble for this final scene. Although lasting but a few seconds, hundreds of hours of preparation were necessary before result shown could be achieved. aia eae ee Bi siy pee EE NTR et WS ee i EEESTIS KERE ANEN TEA T aake ao roana a Sti wna nate aH ree ay ae epee ti t

:

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years have made many of the now-common effects possible. Yellow sand is introduced to secure golden glows. Camphor produces a fine flame; it is used with aromatic perfumes which mask the unpleasant smells of other ingredients. Manufacturers are extremely cautious as to the handling of fireworks material. One plant consists of about 200 tiny buildings spread over 100 acres of meadows. Workers, one or two to a shack, keep but a small supply of materials on hand—enough for a half an hour or so. This supply is constantly re- plenished from a central source. Precautions are taken to see that no accidental combina- tions of chemicals occur. Workmen in one building handling one type material may not enter on that day another building housing different material. The charging houses are very frail, and will practically fall apart at the suggestion of an explosion. The wind, too, is watched, and when it blows the wrong Above—A worker giving the final touch to a large fire wheel. Carefully con- structed and in good balance_ this wheel, when ignited, will turn slowly or rapidly as desired, and show itself in flaming outline. way or too strongly, the plant, which is lo- cated in Staten Island, N. Y., is shut down. The $5,000,000 of reported sales were made, for the most part, in America. The export trade is quite meager because of the expenses involved and also because salt air would in- jure some of the fireworks. But the import- ing of Chinese “flash” crackers bothers American manufacturers. Statistics show that about 65 per cent of all firecrackers used in this country are made in China. This means that Chinese coolie labor is in fairly direct competition with American labor. Manufacturers say that our workers’ daily pay of from four to six dollars equals a [Continued on page 122 | 47

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n AA Melni. Ila E SL TS Si vt ee EN a - 7 Ee v m r + en mo a í ’ k eit aol fu n AEE as ; ie -m Y Cali 7 Dine r, mee “or x r i Ane a? “4, mere g zr Ee, ` j CORT N an ? r SPN LA 71 F z i, > ein T Z Taar f, - COMPLETE working model of an early type railroad lo- comotive has been made by Lynn Rolen, head machinist of the Little Rock, Ark., railroad shops. The model is complete to scale in every detail and required nearly four years to complete. A scale model of the famous DeWitt Clinton also was constructed by Mr. Rolen. He makes most of his own tools and constructs his models from plans of full size machines. A patient and painstaking work- man, Mr. Rolen admits that his biggest thrill comes from finding inaccuracies in original drawings and having his discoveries ac- knowledged by the company which issued the drawings. Church Goes To Sea HEN the congregation can’t go to church, the church goes to the congregation, along the Parana River in the Argentine. This floating church, 108 feet long, has steeple, stained glass Lynn Rolen, Little Rock, Ark., railroad shop machinist, and two of his scale- windows and altar. Built in the model locomotives. At the top is seen a model of the famous De Witt j : i: Clinton. Besides making models, he also makes many of his own tools. government's Buenos Aires ship- yard, the hull of an old vessel was Flashlights Get New Bulbs transformed into a church by the Lincoln arc-weld process. UNIFORMLY more powerful and more Before this floating church made its ap- concentrated beam of light froin flash- Pearance, many of the church-goers of that lights is produced by this new prefocused section were unable to attend formal worship. flashlight lamp, according to Westinghouse lamp engineers. Accurate alignment of the filament is as- sured by placing one end of the filament sup- a port wires in pit of pear-shaped glass bulb and by positioning bulb in the new lamp base within ex- ceedingly small clearance. Photo shows size of new bulb a as compared to ee ee ae world’s Se ieee in pas on Lee rea : : the Parana River, Argentine. Vessel was built because the con- pencil p oint, gregation many times found it impossible to attend church. 48 Modern Mechanix

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Right—-Claudia Schacht, champion parachute jumper of the U. S. S. R., is shown with full paraphernalia just before entering a plane for a leap into space. Aviation officials say that women jumpers have less fear than men and never hesi- Sa ies = a ia Re. tate before jumping from the plane. In contrast fee , to Miss Schacht, who is about to take off for her 3 jump, Valya Lazareva, a student at a parachute school, is shown as she landed after her first jump. e a CPA he te) Y; fer Above—DMirra Zeidenberg, first woman airplane me ` chanic of the Soviet Republic, is shown at work ~ motor at a military flying field. The daughter of Kiev slaughter-house worker. she started her air studies after having worked 14 vears in a glas c tory. Completing her studies. she was stationed at the Military-Technical Institute of the Air Force. m to ’ a la July, 1937

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ee — -> po Sas : ‘ | y

pes Street traffic goes on as usual while gigan- tic construction project approaches comple- tion many feet below. by Don Glassman

TOWER FOR HOISTING i EXCAVATED N] -MATERIAL > D i 3 Dat i E x J £ . N S ; i = a tel ees s= ° s oji T. $ Ye ; + > i : i= if a= r 4 Lare x A ~*~ — A at ay Se Se ea eN i g N s a 4 : M “a afd 23 P ——— > ~ X S = 2 , sn sas sue! | | BUCKET | FOR UN- | LOADING _ INTO CHUTE

ost NDERGROUND flyers crashing through eaves of ' darkness serve the largest metropolitan population in the world—New York. They carry people to and fro every minute of the year; storm, rain, snow or ice —nothing stops them. Under rivers, streets, skyscrapers, occasionally coming up for a breath of light and air, the trains for the most part run underground where the running is good and the tracks are clear. Fancy running New York or London with- out subway traffic. It can’t be done! So long as huge cities flourish, so long as we have street congestion, underground travel is the easiest solution to our problem. Experience proves it. The world’s greatest cities keep pace with

Vio LFA) |= STORAGE TANKS wl hii} FOR OPERATION OF ABOUT 75 AIR DRILLS Modern Mechanix TOWER BASE | 53 FEET BELOW _ STREET LEVEL

n © n Ji ‘ *, maiae T- nent are i e, d ° of ike Ae mit (fd 4 ce ates | " p Toe h eat j i 7 N Da 4 f s 7 A na s eh oe ed a l o ain aa a ee o et E ee, ree eee r E a anan a

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g SIXTH AVENUE 3 NOW R ED SHOWING ELEVATED RAILWAY AND TEMP — Ta ORARY SUPPORTS oe = B d -ai "en NVEYANCE OF OE CONCRETE i = = TO. WHERE B IS REQUIRED —*. timate OH eS METHOD a ll | a + SEN OLUM ae the growth of population and street traffic by constantly extending the routes of under- ground transit. Subway building began as a twentieth-century industry, and it seems destined to go on forever. Before one project We eee is finished, another is under way. The process eg te fae i goes on and on, because people are insisting eo TRAFF j on motion without waste of time or effort. ; _ And speed is not a luxury any more. The population spreading over the wide expanse of New York uses the most elaborate network of underground transit ever built. The city is distributed over something like 0,333 miles of streets, and about 848 miles of subway track are required to serve these thoroughfares with speedy subway transit. The newest link in a $1,000,000,000 subway system is a two and one-quarter-mile stretch under one of the city’s busiest thoroughfares —Sixth Avenue. The cost is $57,000,000, more than $25,000,000 per mile for a quad- ruple-lane subterranean highway, surely one of the most costly bits of rail construction on record. Merely a brief examination of what engi- neers must contend with will give one an appreciation of why it takes so much money and five long years to build so short a subway section. REMOVAL OF v “SS ze) EXCAVATED MATERIAL Ciry Grows —- S July, 1937 | n E g 2 AE a. a es, tt Bins Dee

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y z es Tx ies si ELI z TAL APZ i E aes SEEEN, IA aa rA y7 7) T el zt g F AI AE aS . pa Sita! cs 3 f B } $ j e yi A i “sas a “SIXTH AVENUE ELEVATED RAILWAY QUEENSBORCUGH SUBWAY PASSES UNDER NEW SUBWAY AT 4] 8? STREET NEARLY 80 FEET BELOW STREET LEVEL (> 42ND STREET CBVEL PASSAGE TO TIMES SQUARE SHUTTLE TRAINS sees ete teeter te me = , (ee. Ee | = mn spe ee 0 1 e An artist’s drawing of the intricate network of subway arteries below the busy streets of New York City. The Sixth Avenue Elevated line continues its operation and business goes on as usual during the period of subway construction many feet below. In the first place, the overhead street traffic the pillars of an elevated train structure on must go on day and night as if there were no which passenger trains are always running. construction below. Heavy busses, trucks For twenty-four blocks of the distance, the and other surface vehicles travel the roadway new subway route runs above the tunnels constantly. Also, the same street supports of a high-speed interurban train, Under one Newest link costs more than $25,000,000 per mile as public continues demand for more and more travel aids. AX to Modern Mechanix f Ma. pe Ae Ah v ; 7 ba z = ` b LAT Wiese eh a dhed a a EE bay Ase | lL . A i lie Lia : fid im es È h pew” f n e -e i£ — Dm LEE a i) ee C. ae a t pa . = = ps P n

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FOUR TYPES OF TRANSIT FACILITIES AT 42 NE ST. AND SIXTH AVENUE ee Sees 2B) BWAY CONNECTING TIMES SQUARE ™ DG L STATION AS |T PASSES OVER SIXTH AV SUBWAY AT 42 N9 STREET > SES O XT AVENUE $ — panic a Gris x f Va et wv qh’ OGF eR ` e: = wie EP “a “ee = ‘ae yie: r » AA le 2 an g` f OA 3 N "r > va (= Ps ~ y Y it ; w : ar 4 =. sri 2 ~~ A . + A > os aba a Wh md eS ee Ae i —~2 K F 3 Q TAH S ` o O F aie g tar bee S| ey ¥ t m . a s 9 $ pd ty Sir 7B: ee ` ER mosis -a Va a a i i í a "ý G r rh

RAMP TO EXPRESS TRAIN LEVEL

ees ARCADE aT STREET LEVEL

ea ~~ Rp A e Aea n PC le a ee hacan ei 7 THE DEEP-DOWN QUEENSBOROUGH SUBWAY Yat He a mem, -e a pyn — i ‘ . jae \ - EESE EPET yp Pa ~

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Shuttle train connecting Grand Central with Times Square will pass over Sixth Avenue subway at 42nd Street. Queensborough Subway operates at a depth considerably below Lexington Avenue line. Above both is complicated track system at Grand Central. street intersection, it must leap over the cf a seventeen-foot aqueduct from the Cats- Pennsylvania Railroad tunnels, dive under kill Mountains, carrying a stream of clear another subway and a tunnel, and support water for the city’s daily use. Gas mains, the elevated structure over the street. steam pipes, electric conduits, sewers, cables, © To all this difficulty is added the presence sub-basements, and underground freshets subway travel gives public one of its biggest nickel’s worth in form of a 26-mile trip under city streets. July, 1937 53-

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Se cme NS ‘a SAPD, Below—Patrick Halloran, a sand Ore” ao ed gas “yf hog, climbs out of a 30-inch pipe under the Hudson River Cn where the new Midtown Tunnel . is nearing completion. Depth at which these men work regulates the amount of their pay. One of their most serious dangers is “bends,” afflicting those who go from ome pressure area to another too rapidly. a, P i Y a y s - ` W V y - f S E S AN F vt 4 r Th « n G T N EON AS. s J h ’ ` Toa 3 i -Yeb Riges is E ANEP FET E N oar t 0 , 5 Se sees k yo ae at id a AN n g ors x sna vb a ats Ty + Tsien k ` ">i y 5 Bes at fi oe .. ai ee ae iran] >) ges _ wa “tae SR be ee ee ed ele eS ee PEERS ets A om iad Ps “rN Amd Excavators at work on the New York Midtown Tunnel. Thou- sands of tons of rock are lifted to the surface in huge buckets, Drill marks are still visible on the sides of the stone. add to the difficulties. Sky- scrapers must be pinned up, foundations carried down, cables separated, excavations removed, and concrete poured. Steel beams are pushed through nar- row openings. Air drills attack the hard granite and drive holes for dynamite. Then there is the underground blasting, most ticklish job of all. Every blast is “in the lap of the Gods.” If it fails to go off ac- cording to plans, something gives way and perhaps the whole struc- ture may tumble down. Careful calculations and the most pains- taking labor enter into subway construction. Hundreds of thousands walk on the rough planks covering the streets, but few know what actually goes on Above—Surveyor W. H. Fran- below. Underwater tunnel construction is another in- cieco hecki the alignment oi ths dustry that bids fair to develop into permanency. The iane coe eee ae DR East River takes the world’s record with ten double- tion of the tunnel so that the : : s t tart n opposite track underwater tunnels. Five immense bridges span a AE ie eke ade caactly this same channel. where planned. Ever since the completion of the Holland Tunnel [Continued on page 131] J Ja

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Trailer Camp Brings Back Tepees For Sleeping NDIAN tepees as_ sleeping quarters for guests is a novel arrangement offered by Bob Callahan of Los Angeles, pro- prietor of an auto and trailer court. The entire court takes on an Indian atmosphere mixed with a touch of early California. Be- lieved to be one of the most un- usual courts in the country, an opportunity to sleep in a tepee is finding considerable favor with the visitors. Although rooms are available for guests, the proprietor reports that tepees bring as high a price as the best of the regular rooms. Before opening this court, Mr. Callahan spent a por- tion of his life studying and writing about Indian life. As trailer design gives more and more of the convenience and comfort of home, This trailer camp supplies tepees for its guests who do not wish to sleep in their trailers. of sleeping in this ancient style brings as high a price as for the best rooms. Receiving considerable favor from the visitors, the privilege many trailer camp proprietors are offering a more interesting instead of a more luxurious place to sleep. In keeping with this trend, Mr. Callahan has introduced this sleep-in-a- tepee idea. Meat Is Delivered In Mechanically Refrigerated Truck Se= inthe aay oes’ r LEERS Uan nanoa iu Dressed meats travel from wholesaler to retailer at a correctly mantained tem- i _A mechanical refrigerating plant operating from car engine gives 35-degree inside temperature regardless of outside conditions. perature in these trucks. MECHANICALLY refriger- ated meat delivery truck, believed to be the first of its type in the country, is being operated by the Frank Banfield and Sons Dressed Beef Co., of Tulsa, Okla. Delivering its products to the retailer at a correct temperature, the company has found the method so successful that de- liveries are being made as far as 60 miles from the cold storage room. Each truck is equipped with a power driven refrigerator unit. Hose At Gas Station Entrance Announces Customer's Car LENGTH of rubber hose laid across the entrance to a gas station in Fort Wayne. Ind., is used to announce the arrival of a car, by means of a buzzer in the station. Air pressure caused by the car driving over the hose causes a switch to close, which in turn operates the buzzer. With this device, waiting on the part of the customer is minimized, and it is not necessary for the attendant always to be watching for a cus- tomer’s arrival. The attendant may carry on other duties without slowing service. Pressure caused by a car passing over a rubber hose causes a switch to close which in turn operates a buzzer at this Fort Wayne, Ind., gas station. Needless waiting of customers thereby is eliminated. 59

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by Aubrey D. McFadyen ARLETON ELLIS is one of the truly great chemists of the age. He was among the first to crack and refine petroleum to get anti-knock gasoline. He is the man who met Uncle Sam’s war-time plea for a fireproof “dope” for airplane wings by extracting it from petroleum, even while Gov- ernment chemists were saying it could not be done. He is the man who taught the world how to separate out of petroleum all sorts of important chemicals, isopropyl alcohol, for instance, thus bringing to the public for less than $1.00 per gallon a commodity which previously sold for $5.00 a gram. He is the man who revolutionized automobile paints by making a durable coating from tung oil and soy beans. In short, he has made over a thousand inventions—676 already patented, and approximately 400 applications pending before the United States Patent Office. The inventions of no other chemist in history enter into the daily life of the public in such variety of ways as do these of Carleton Ellis. Though best known for his work in connection with the petroleum industry, paints and varnishes, synthetic resins, and urea plastics, his inventions touch nearly 56 Producer of more than 100,000 new products finds time to serve as consultant and write many books about chemistry. Carleton Ellis, whose inventions enter into daily life more than those of any other chemist in history. Though best known for his work in con- nection with the petroleum industry, his inven- tions touch nearly every branch of the chemical arts. Soaps, cosmetics, chewing gum, butter, floor wax and dog biscuits are some of the products in- corporating improvements worked out by Mr. Ellis. every branch of the chemical arts Soaps, cosmetics, chewing gum, butter, floor wax, the dog biscuit, even the ink of this print, may be mentioned as some of the familiar things incorporating improvements worked out by Carleton Ellis. Several years ago Mr. Ellis went to Ger- Modern Mechanix

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many armed with letters of introduction to the heads of certain chemical concerns. The first note was received cordially, but incredu- lously, “What,” one of the German scientists was heard to inquire, “is Carleton Ellis doing with letters of introduction? Why, every scientist in the country is already well ac- quainted with the name.” It appears on too many patents on ideas they had ardently wished to claim as their own. Indeed, his fame is world wide. From all corners of the globe come proposals from chem- ists and chemical students seeking experience in his Montclair, N. J., laboratory. A Japanese chemist once offered to work four years without pay for the simple privi- lege of learning under Ellis! Mr. Ellis is not the sort of scien- tist who keeps his sight focused on a test tube. To the contrary, he is ever looking about the world, into industry and especially agri- culture, with an eye to its future needs and resources.. Seeing a need, he looks for the right <6: an Lass medicine. When he finds the right medicine he administers it back to the world. The uncanny thing about it is that he finds the right medicine—and patents it—long before the industrial chemists come across the idea. Consequently many manufacturers pay Ellis royalties. Tuty; 1937 ' « 2 tee bl Ò nel i a, aa aT A... = _* A camera received upon his eleventh birth- day as a present from his father switched the boyhood ambitions of Carleton Ellis from electricity to chemistry, and started him upon his brilliant career as a research chemist. The wonders of the chemical reac- tions of photography seemed to ignite the experimental bent of the lad. Every picture

Left-—Mr. Ellis (left) and his assist- ant, Dr. Root, inspect an assortment of articles developed in the Ellis- Foster Laboratories. These articles include such things as lamp shades, radio and clock cases, toilet articles and buttons. Above—Mr. Ellis in the petroleum division of his laboratory discusses progress on Diesel motor fuels with an assistant, Dr. Swaney. he made included some chemical experiment intended to improve photography. When his thrifty New Hampshire parents protested his experiments as wasteful extravagance, young Ellis resorted to exploiting his photographic skill throughout his neighborhood as a means [Continued on page 118] outta nate ar thas s S.A ite

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Kuda Bux as he walks over the hot stones in a demon- stration of faith. He claims that those who are able to walk through fire unharmed do so because of their religious faith. CIENTISTS have recently tested the , Jr famous “fire walking” ceremony under me tS OA A ere: ; A eps $ $e 8 ute eA Bing their own stringent conditions of control. OO is et fh ad A young Kashmir Indian by the name of A , e — Kuda Bux walked barefooted back and forth a n across a trench of glowing embers—emerging #5 unharmed from the ordeal. We have all heard of these fire-walking ceremonies, which have been undertaken by natives in Fiji, Tahiti, Trinidad, Japan, the A spectator tries Walkin TATON OR tite Nedi Straits Settlements and in other parts of the ately after Kuda B NEARE AERE O : š > ing but few steps, hlm as Porce tO leave Hre pit, Wol ld. And, just as Shadz ach, Meshach and Examination of his f6@R0giselosed severe wurtis: 58

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bare teemwalk through fire Without being burned as Science watches and fails to Oller G@ Suildble explanation. Abednego emerged from the “fiery furnace,” in the Old Testament story, so do these mod- ern fire-walkers seemingly escape burns or injury. How can such a seemingly impossible feat be accomplished? All the witnesses are agreed that there are no burns upon the feet.

Hereward Carrington What happens? Kuda Bux says “faith” is the answer. His contention is that all those who are able to walk through the fire un- harmed do so because of their religious faith. Sceptics, on the other hand, have asserted that either the fire was not . really hot enough to burn, or that Sh the skin of the feet of the par- m= ticipants was calloused or ù chemically treated in such a Wa manner as to give protection ri P from the flames. * . But can this be true? ©. The fire has been tested ee,

by means of ther- ae <8 mometers, and fe found exceedingly

Bn + - hot—as we shall per ele „see. Also, the e Reet of the Walkers have peen examined By medical men, andiih ey have stated that they are motepme pared in any way.» Na- tives Nagy e walked, Eure- peans have walked. Cases of injury are rare-— and when they have occurred it is usually because the participants did some- thing they had been warned not to do! Let us give one or two illustrative cases of firé walks of this character, which are typical of many. The first is from’ Fiji, and is reported by Dr, T. M. Hochen, F, L. §., Dr. Colquhoun, 59 Fire Walker Kuda Bux being examined immediately after a ‘stroll’? through fire trench. He showed no sigh of having been burned or even scorched.

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An Indian fakir entertaining a crowd in Delhi, India, by treading on a bed of live coals, which is one of. the most spectacular and unexplainable feats of these mystic performers. and Mr. Vaughn, of the Meteorological Department of the Island of Suva. Three days were oc- cupied in the building of the oven and the prepara- tion of the fire, which was lighted from thirty-six to forty hours before the ceremony took place. Stones were pulled over the fire, which in the course of a few hours be- came white hot. The oven was circular in shape, 25 to 30 feet in diameter and about 8 feet deep. It had slightly sloping sides. Three photographers were present to take pic- tures of the firewalk in actual progress. A ther- mometer was held over the center of the oven, by means of a long pole, about five feet above the surface. It showed a temperature of 202 degrees F. It was [Continued on page 133] Ir group demonstration of faith. Although the youngster does not appear to be enjoying the experience, it is claimed erg when a person does not have sufficient faith to walk through the fire alone, mahy. times iz is possible to acquire immunity by holding the hand of one more versed in the art. Tests of fires used show the inside temperatures to be as high as 2,552 degrees F. (hot enough to melt steel), while surface tempe rature of 800 degrees ate’ not uncommon.

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oe oe oe ———. | Me man ee fiies = ok me ee oe le eee pl Pee ee ee wp i —_ ee Pa i Swamp Furnishes All Material For Unique House HEN George Daynor, ex- prospector from Alaska, found himself with but $4 as his total capital, and in the country near Vineland, N. J., he spent those last dollars to buy four acres of swamp land that was being used as a dumping place for dis- carded automobiles. From this desolate, mosquito infested land, Mr. Daynor has built a dwelling such as is seen only in fairy tales. Working alone, and with few tools, he felled lumber and col- lected stones in his woods, dug clay in his swamp and tore apart | the rusting motor cars to obtain their struc- tural steel. Using the clay as mortar for outside ma- scrap Metal Becomes Engine A model of a logging donkey engine has been constructed from scrap metal by Sydney Woods of Vancouver, B. C. Using wood as fuel, this foot high model operates realistically. WORKING model of a logging donkey engine was constructed of scrap metal by Sydney Woods of Vancouver, B. C. Tin cans, odd pieces of metal and old lead went into the construction of this foot-high model. A “depression palace”? was constructed from the material found in a swamp by George Daynor, shown standing on the chimney structure. Arch doorways are shaped like giant keyholes, fenders of old cars supporting the masonry. sonry and plaster for the inside walls, and heavy timber or steel from the cars for roof beams and columns, he erected a house both grotesquein design and sturdy in construction. Arch doorways are shaped like giant key- holes, the fenders of old cars supporting the masonry. Numerous tall spires made from car rods covered with clay, rise above the roof like a forest of lances. Inside, the clay walls are tinted with pow- der from crushed brick and stone. Truck Carries Own Trailer TRAILER truck which folds up when not carrying a load, is being used in the west for logging purposes. Controls operated by the driver in the cab, causes the rear section to be drawn up on the truck, thereby giving greater safety when operated on the highways. It may be unfolded and made ready for receiving a load within a few seconds. Eee , an EW OF As an aid to highway safety, this trailer truck was developed for western logging purposes. When not loaded, rear portion is carried by the truck. Machine is equipped with air brakes. 61 ee ee ee eee Oe ea ee ee Ly tan

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2 | Wal | Above-—Looking up at the giant radio towers located at R. C. A.’s “Radio Cen- ter,” Rocky Point, L. I. These towers support the antenna for the largest radio station in the world. At right, in marked contrast, is the antenna system for an Egyptian Government station near Cairo. © THE smoke of foreign conflict rises above the horizon, students of world affairs realize that international broadcasting is perhaps the most potent arm of propaganda to dump nations into the inferno of war or to maintain peace. Almost daily the press tells how foreign nations are using that marvel of modern science to tell the world via short-wave radio of their nationalistic aims, armed strength and economic prestige. Within the next few months, the doling out of the coveted radio frequencies on a world- wide scale will be taken up by two inter- national parleys, with the allocations of ether channels to international broadcasting as the outstanding and most controversial problem. First is the biennial meeting of the Inter- national Radio Consulting Committee, com- 62 D RADIO Priceless radio fre- quencies will be doled out at international conference to be held in Cairo early in 1938. by Roland C. Davies = Modern Mechanix

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a as T —— “Se hd a-t T ULNE m eS a ~ ` < r i 8) ae Oe aa) we a DAAE NEEE rcv RINAS . erry S BATTLE LOOMS epii ay eas iki

ie iif: “fic i

Miili T

4 Lat ae Above——Parliament Building in Cairo, where the Third International Radio Conference will be held in February, 1938. World diplomats will gather here to allocate the much-coveted radio frequency spectrum. monly termed the CCIR, at Bucharest, Rumania, in the Spring of 1937. Then will come the Third International Radic Conference, which meets every five years, to be held in February, 1938, at Cairo, Egypt. The Cairo conference will capture the eyes of the entire radio world, because it has treaty-making powers in drawing up the rules that govern frequency allocations, in- terference and use of radio. The findings of the CCIR at Bucharest, however, are purely advisory and are confined to techni- cal problems. They carry the weight of a world consensus for the guidance of the treaty-making assembly at the Egyptian capital in 1938. During the last six months a score of American government radio experts, aided by the leading technical brains of the nation’s breadcasting and communications companies. have been busy drafting the United States pink ees boy ruler of Egypt, wie may open proposals to be presented at the Cairo con- the conference when it convenes early next year. s à - £ The American delegation probably will be assisted ference. The American program Is to be for- by leading radio authorities as unofficial advisors. warded by this coming November to the other nations, which in turn send their proposals kna te.) we iil es d's Êt aaa ge k l à ) -ea o i a

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ia aoa ee ee ee ee ee en | eee eee a), = if et ? f tr i a l oh to the United States so that all may study in advance the plans that will come before the international con- ference. There is a saying in world capitals that the United States has not only never been defeated in a war but also has never lost an international radio conference, although this nation may have been the victim of shrewd diplomats in recent arms and economic parleys. Back in 1927, when the nations first assembled in Washington for a world radio agreement, the United States took the leading role. At that time the use of radio by ships was the principal international problem, with broad- casting limited chiefly to national boundaries. At Madrid in 1932, broadcasting became the critical prob- lem, but the squabbles were confined in a large degree to European nations. However, the Cairo Radio Conference is expected to become the scene of a bitter fight. The larger European powers—England, France, Germany, Italy and Soviet Russia—together with Japan, are to be pitted against the smaller countries, while the United States will hold the balance of power. The short waves for international Gerald C. Gross, engineer of the broadcasting will be the issue at stake. In the past the Federal Communications Commis- . ; sion, who has participated in most of larger nations, due to greater technical progress, have the international radio conferences. grabbed the better allocations for broadcasting and [Continued on page 151] ets Ae eee The Federal Communications Commission, which will have charge of preparing the United States Position at the Cairo Conterence. Left to right, front row, E. O. Sykes, Broadcast Division chairman; Anning S. Prall, Communications Commission chairman; Irwin Stewart, Telegraph Division chairman. Back row, left to right: George H. Payne. Norman S. Case. Thad H. Brown and Paul A. Walker. 64 Modern Mechanix

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Mobile Microphone Boom Aids Voice Pickup SPECIAL long boom and microphone now are being used by the motion picture studios to pick out the conversational lines of any actor being filmed. Even though it is used on a large setting, the boom, having a 25-foot radius, is ample for pick- ing out the desired dialogue and controlling the sound effect by selecting what is to be recorded. The unit rests on rubber tires for silencing, and may be pushed about during filming, while the sound man controls the movement of the boom to follow the move- ments of the actors. Concrete Weight Cut NEW road surface contain- ing a material light enough to float in water is making a marked reduction in highway sur- face weight. Used in the concrete slab on the San Francisco Bay Bridge, a 30,000,000-pound weight reduc- tion was noted. Called Gravelite, the substance effects the weight reduction be- A mobile microphone boom having a 25-foot radius makes it possible to f j pick out conversational lines of any actor during filming. The unit rests on cause it weighs but half as much rubber tires and may be pushed about while sound man operates boom arm. as the sand and gravel it replaces. | It is made by burning clay and shale in such a manner as to cause them to expand into a light weight material having unusual strength qualities. Transportable Transformer Fills Emergency Need PORTABLE transformer at- tached to a railroad flat car has been constructed by the Ger- man State Railway. For use dur- ing emergencies, the transformer will be used for temporary re- ne f placement of defective trans- ae T renee Because installation of units of large size sometimes entail a con- siderable transportation problem, this unit, permanently fixed to the special railway car, may be sped to the scene of an emergency and service may be continued with a This portable transformer, used in Germany, may be moved rapidly to replace minimum of interruption to the a stationary unit out of service, thereby reducing the service interruption to a minimum. Special car was constructed by the German State Railway. consumer. July, 1937 65 Weds He ~ .,, | oa ee eee ee ee 4 k a —

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qv Improved Gyropilots The rectangular section of the instrument panel visible between the two pilots of a United Air Lines “Mainliner” represents the installation. of the latest type Gyropilot device which helps maintain level flight despite rough air. YROPILOT devices, the “automatic humans” that actually pilot giant air- planes, have proved to be so efficient that installations in commercial and private air- craft have increased from a single device to more than 400 within three years. The latest type weighs only 60 pounds and its action is based on pneumatic and hydraulic principles, having no clutches, motors, or electric contacts. The improved devices detect the slightest change in an aircraft’s course or flying position and instantly apply corrective movements to the controls. Thus, in rough air the plane is not sub- jected to the larger angular displace- ments resulting from delayed manual control, insuring smoother flights. ne sess Circuit Improves Radio N INGENIOUS circuit intended to eliminate the detuning of a ship’s radio transmitter and receiver caused by rolling seas has been patented at Washington, D. C., by Jean Rebotier, of Paris, France. Adopted By Aircraft Operators model rockets, these English schoolboys hope to build rocket that will travel to Mars or some other distant planet. When a ship rolls at sea its radio antenna tilts toward and away from the water. This causes a change in antenna ca- pacity which may throw the receiver out of tune and the transmitter out of control so that the radio signals received or sent out may vary in in- tensity or be totally lost. To compensate for this trouble, the inventor connects the antenna with a variable tuning element, an adjustable condenser, which is worked automatically by the rolling motion of the ship. No matter what position the ship is in, its antenna capacity remains con- stant. Signals sent and re- eeived, therefore, cannot vary with the rolling of the ves- sel, but remain constant. Schoolboys Build Model Rockets XPERIMENTING with model rockets in the hope that their research will some- day enable them to construct a huge rocket which will travel to the planet Mars, a group of 14 schoolboys in Man- chester, England, have organized the Inter- planetary Society. The members attend weekly meetings at which each boy takes an active part in constructing the model rockets used in experiments. Forming the Interplanetary Society to conduct experiments with a huge Modern Mechanix

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Crane Serves As Temporary Ship Lock GIANT crane has been” pressed into service as a novel ship lock at the Bonne- ville Dam project on the Columbia River in Oregon. Tugs and other small craft navigat- ing the river are lifted over a bulkhead pend- ing completion of the dam’s permanent water lock which will permit passage of ocean going vessels and other river craft. The Bonneville Dam is located 40 miles above Portland, Oregon, and the entire Pacific Northwest will benefit from the power, navi- gation, flood and irrigation facilities which it will provide when completed. The waters of the Columbia River will be confined be- hind the 1,250-foot dam, creating a 100,000- acre reservoir. Engineers of the War Department are con- structing the dam under an initial allotment of over 32 million dollars from the Public Works Administration. Angler’s Kit Carries Motor ESIGNED especially to provide fisher- men with a convenient way of trans- porting a small outboard motor and fishing tackle while enroute to a distant lake or stream, a compact metal carrying kit has been developed by a leading manufacturer. Completely loaded, the kit weighs less than 30 pounds and is carried like a suitcase. The cover of the kit provides room for three casting rods, while the kit proper pro- vides space for a small outboard engine, a one~gallon fuel can, a 17-inch tackle box, three or four reels and a tube of grease. tetas oa Be eae alte ee ee ae et eee ee aoe ned $ a i E 3 _&. Fis oe F Kus - Waterproof in construction, this compact fisherman’s kit provides ample storage space for a small outboard motor, tackle box, one-gallon fuel can, and three fishing rods. July, 1937 De NEPRC DRA Ste ies ee eee eS fii tees a Nee tee Pressed into service as a temporary ship lock, this giant crane hoists tugs and other small craft to higher water levels of the Columbia River at the Bonneville Dam project in Oregon. U. S.-Soviet Air Line Planned NEW and direct international air route between Moscow, capital of the Soviet Union, and U. S. territory, is being discussed in Moscow. The route, as planned, would provide air communication between the two nations without the need of traversing the frontiers of Europe or other foreign countries. The proposed route would be 10,000 miles long, running from Moscow to Nome, Alaska, and then to Seattle, Wash., via Fairbanks and Juneau, Alaska. With good airports and modern high-speed airplanes, it is estimated the route could be covered in four to five days. Several Soviet aviators have already pio- neered part of the route, crossing the sub- arctic regions of Siberia. An agreement be- tween the U. S. and Soviet governments is needed before the route can be projected further. 67

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LACK GOLD Lone soldier of U. S. Army's farthest-flung outpost invents methodofconverting Alaska’s j useless surface oil tocrude oil. Master-Sergeant Stanley R. Morgan, Signal Corps, U. S. Army, inventor of the process that may make Alaska a new source of wealth. OWARD America’s last frontier the march of empire drives, and a day may come when the white and mysterious Arctic Coast will be transmuted—through the twin alchemy of black and yellow gold—into a thriving pioneer country, a new Eldorado. This is the dream, a dream fast taking shape and substance, of Master Sergeant Stanley R. Morgan, lone soldier of the United States Army’s farthest-flung outpost, who possibly knows more secrets of the Land of the Midnight Sun than any other white man alive. Sergeant Morgan, Uncle Sam’s Law North of 68, brought the bodies of Wiley Post and Will Rogers out of the wreck of their Siberia- bound plane near Point Barrow, and at once skyrocketed into world fame when he wire- lessed from the top of the world the news of an American tragedy—the death of heroes. As a result of his part in that drama of the Polar No-Man’s-Land, he was promoted by the War Department to the highest enlisted grade, and granted an extended furlough to visit “the States” and receive high honors from Washington officialdom. The furlough he found a mixed blessing. On one hand, he soon became homesick for 68 PVla lt es. Above-——Time honored method of transportation in the Arctic. This photo was taken near Barrow. This is in sharp con- trast to the newer method de- veloped by Sergeant Morgan. Right—Huskies look at their new rival, the snowmobile. Frotit end rides on skiis to make steering possible over the snow. Sergeant Morgan takes long trips in this machine. the white solitude of Point Barrow, but, on the. other, his presence in civilization served the needs which are his leading motives; development of the Arctic Coast and practical help for the Eskimos. Morgan’s Alaska is not the Alaska of timber and mountain torrents. It is a flat and silent stretch of coastline a thousand miles long, without a tree or a bush anywhere. It is like a spectral prairie on a dead planet, facing for eternity toward the mute snow wilderness of Modern Mechanix

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jai FRO by Paul Conant Right-——Map showing area sur- rounding Pt. Barrow, and the location of the oil lakes. tt Me en ee Eiee i f yii 7 x { T TA y Si NDIcoTt Mi N we topo warps the North Pole, a prison land guarded the whole year ’round by the grinding Arctic ice pack. And yet—here are natives who need the things that make even primitive life en- durable, and here are glittering treasures which have always delighted white men. To bring the natives the things they want, and to open the Northland’s ice-locked treasury to the whites—these are the prob- lems that Sergeant Morgan believes he is solving. But how? July, 1937 Sergeant Morgan, working in the labora- tory of the Eighth Signal Service Company in Seattle, waiting for the summer breakup of the Arctic ice pack that will allow him and his family to go “home” to the top of the world, tells about himself and his dreams. “There are two things,” he says, “that the Arctic Coast needs more than all others. They are things you take for granted here in the States: transportation and fuel. “You know, the whites up there—and there 69

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ey BOS | AP Brel 5 Corre eee T Sa ee ot tN od ITAL er eles Ie A en De i SAT a he ied Ct Oe ee yee ne ie ae | NE! ed Oo ee eee ee etree 24 Oat 2 ee ee Ls LO ee, ayy yeh sos. len Nese Sd SPS AS] oie ee is ret tes Ore Nese) oreo Rr ont tel aS Tree Sl tetas eee PSAP ATR oe ia aa te Ree ott Seer! C9 ee TA a et] Qos tes © eee č Ern Ea AEN r E ed arts et eat: i Fimm iA T ANC ois eee ce aot Nie ees eel Ieee tee, ete i : p G 3 : Sd ma I c Rs TE; a ea i - = Lae R3 Ged a = G ; " a ot D AR n j E "n I TROE E 4.5 O x ` = F š ; Si ) ai eee So es ; poe as Mes he Rite thas E aa y bag SA as rae ae em AS e ee = y pois E moneys f ia wee ‘ icone a Right—Mrs. Morgan, wife of Sergeant Morgan, and official weather observer at Pt. Barrow. Above—A group of Eskimo boys. Sergeant Morgan says that Eskimos of the Arctic Coast are the most unspoiled cf any primitive people. His chief official duty is that of performing marriages. are only twenty-five of us on the whole Arctic Coast—have to import coal, which costs around $45 a ton. The natives, well, they have always used whale oil and they still use it. But the whales are disappearing. “As the whales disappear, the natives will disappear, too. They’ll move to other hunt- ing grounds and they’ll die out.” This poverty of fuel hurts Eskimos and white men alike. For the Eskimos, it spells tribal death. For the whites, it closes to them a land of dazzling promise, of immeasurable potentialities. Faced by the grim hostility of this far Never-Never-Land, most men would have given up the whole problem as a bad job. But not Sergeant Morgan, who has in his blood the vital resourcefulness of the American soldier and the American pioneer. One day, many years ago, when he had first come to Point Barrow to establish a Signal Corps radio and weather station on the farthest north tip of the continent, he was exploring the country fifty miles southeast of his new post of duty. It was then that he dis- covered for himself a strange manifestation of nature that may be a key to the icy treasure vaults of the Arctic. “Suddenly,” he says, “I came upon a dark lake in the snow. At first I didn’t know quite what it was. It seemed rather weird and mysterious and impossible. Investigating, I found that it was oil—heavy, gummy surface oil—a whole lake of it! It proved to be five miles across, and later I found three other [Continued on page 140]

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> Sep ey eee ae ye ae m pN eee i E le Streamlined Engine Hauls 15 Cars At 80 M.P.H. ESIGNED to haul a 15-car train at a maximum speed of 80 m.p.h., the first of a fleet of ten streamlined steam loco- motives has been placed in service by the N. Y., New Haven & Hartford Railroad. The huge engine is 97 feet long, including a 16-foot tender that carries 16 tons of coal and 18,000 gallons of water, enough fuel for a non-stop run between New Haven, Conn., and Boston, Mass. The boiler of the locomotive carries a maximum steam pressure of 300 pounds, with a working pressure of 285 pounds, providing initial trac- tive effort of 44,000 pounds. Completely equipped to run, the engine and tender weigh 694,500 pounds. The tractive equipment con- sists of four small wheels under the leading truck, six 80-inch dise driving wheels, and four trailing truck wheels. The engine frame is a 50,000-pound one-piece steel casting, eliminating over 250 bolts and rivets for- merly used in engine construction. Micro-Wave Tube Produced IMILAR in size and shape to the seed of an oak tree from which it derives its name, a midget “Acorn” radio tube has been produced by a leading manufacturer. In- tended for micro-wave work, the novel tube is robust in construction and although designed primarily for use on one-meter wave lengths, it is said to be equally efficient on ordinary wavebands. Radios as small as an average cigarette case may soon be possible as a result of the development and perfection of the new midget tube, considered one of the world’s smallest. , At present it costs Equipped with automatic stokers and powerful enough to haul 15 passenger cars at 80 m.p.h., this 97-foot steam loco- motive is the first to be specially designed as a “streamliner.” Electric Fan Fits Purse PERATING on two small pen-type batteries, a novel electric fan has been developed by a New York City manufacturer. Small enough to fit into a lady’s purse when not in use, the tiny fan is specially designed for use at the theater, being noiseless. The fan blades do not revolve fast or hard enough to injure the fingers should they ac- cidentally contact them while whirling, yet they provide an ample, steady breeze. Bat- tery refills are available. $12.50 to produce one of the tubes, despite their tiny size. As in other fields, increased production in the fu- ture should lower the cost materially and make the tubes more The micro-wave radio tube shown available to experi- Two batteries in a compact metal holder supply above is dwarfed when placed beside t the power for operating this novel fan designed an ordinary tube for comparison. menters. for use at theater or opera, being noiseless, 7 | g a J fo boos ; ee eer ee be gy a eee jte = : gii i i | i le ce ae Ss ep ee a ee a . fell Bsa eh ete MR ow) cad a a eae ee

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Ww k eee “a a a Aa 4 Ti re tn Ws Se eS > : ee E tye Sy T DG z a he, s Piia ie, 2 “2 > Á -A X na o Left — Glass bead on metal wire before lacquer is applied. Acid dissolves wire leaving bead with hole. Below—Bead op- erator with automatic twirler turning the wire forming several beads. Note the battery of gas flames and glass rods. Whipping a sticky necklace around the head of an imitation- pearl importer, irate actress un- consciously started new industry and gave women a new jewel. by Austin C. Lescarboura Left—Carl G. Pfeiffer. in- ventor of the indestructible imitation pearl, is shown studying examples of his handicraft. Only an ex- pert is able to tell differ- ence between the oyster’s product and Pfeiffer’s. WOMAN’S temper turned the trick. When that musical comedy star whipped the sticky necklace about the head of the imi- tation-pearl importer, she started a new in- dustry with a bang. Staged in a Fifth Avenue jewelry shop two decades ago, that episode furnished the incentive for an outstanding eareer of research leading up to the present American indestructible pearl industry and the emancipation of our ladies from the hor- ror of gelatinous black rings about their fair necks. Pearl necklaces today no longer run at the first sign of warm weather. Nor do they cost a fortune. Fresh from the Wild West of Colorado and Above—Worker placing glass beads on wires or toothpicks and then placing them on circular discs for dipping in lacquer. After dipping they remain on discs during drying operation. Repeated dipping and drying gives desired sheen. Modern Mechanix

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OYSTER At ITS wearing a seventeen dollar Stetson with genuine hand-tooled leather band, Carl Pfeiffer stepped into the picture as his cousin, that pearl importer, stood pondering over the future of the imitation pearl necklace trade. Carl was the friend in need. Despite his pro- tests—he had never seen the ocean, much less an oyster at work—Carl was told he must now turn oyster and produce indestructible pearls forthwith. To complicate matters, this cowboy was neither chemist nor mechanic. He had come to New York to seek fame and fortune on the vaudeville stage. But no mat- ter: he was now commissioned to create artificial pearls which would defy warm weather, perspiration and age, and which would. match the natural product in shimmery beauty. And so the erstwhile cowboy and would-be actor went to work. For months he haunted the libraries, poring every bit of literature on pearis. He supported several translators. From the start he ruled against the alabaster support heretofore used for making imitation pearls, and insisted on glass. Soon he evolved . 7 . 7 a means of making glass beads in quantities and of various graded sizes. Above — Better grade ee ie . . . beads are sprayed with . With suitable glass beads available, Carl teers ia clea turned to the intricate subject of coating. He as many as 14 coats. i ; ey Coats are varied for decided to retain the essence d’orient or desired sheen and hue pearly solution used by the French and other pearl artisans. But he flatly rejected the [Continued on page 142] appar ater Ek D Y iri g y y i RTE F on E ae N r ip o DEEE P aie & er. 5 Above—Dipping a number of beads at the same time. They are then placed on automatic dryer in background. Right—Hand dipped pearls coming off automatic dryer after half hour twirling period. July, 1937

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Small Utility Tools Are Attached To F inger Tips Miss Lillian Greneker, New York artist, illustrates her invention which she claims may revolutionize the use of hands and fingers in aits, crafts and industry. Thimble- like devices are attached to the finger tips. Special Truck Recovers Tank RECOVERY squad has been attached to the Royal Tanks Corps for the purpose of recovering tanks which have become stranded. Mobile repair shops have been provided for necessary repairs after the tanks have been brought back from the field. A special tank carrier, known as a trans- porter, is capable of pulling the stranded tank up onto its platform from the ground. A hawser, operated by the transporter’s engine, pulls the tank onto the runners leading to the truck platform. Stranded tank being loaded on special truck used by the Royal Tanks Corps in England. Equipment makes possible fast loading from ground to truck. Truck engine furnishes power. 74 MALL utility tools fitted on the finger tips are the invention of Miss Lillian Greneker, New York art- ist. This invention, she claims, may well revolutionize the use of the hands and fingers in the arts, crafts and in- dustry. Tentatively named “Fingertips,” the thimble- like devices extend verti- cally from the finger tips. The tools, in fact, become ex- tensions of the fingers which are thus released as inde- pendent agents capable of performing the work nor- mally required of the hand or a combination of several fingers. Among the objects at- tached to the fingers in this manner are various sizes and types of brushes, a crochet needle and pencils. Botany Taught In Solarium cee ee o ms Students attending botany class in the new domestic science school in Ilford, England. Building is designed to permit students to have a maximum of sunlight during class periods. NEW domestic science school recently has been opened at Ilford, England, in which the students attend botany classes in a solarium. Designed along modern and original lines, the school building permits a maximum of sunlight to the class room. The school has its own telephones, gas and electric cookers, a model drawing room, bed- room, bathroom, and kitchen for teaching. Modern Mechanix oe ee

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Only simple tools are needed to make these proj- 3" DIA. STIFF PAPER WHEEL HOLD IN 7 PLACEWTH § METAL STRAPS y TO PORCH ARAIL: This decorative window box will add beauty to the surroundings of any home. Censtruct the box from any stock to the dimensions indicated above. Cut the trimming from ply- wood and paint it a color that will contrast well with the flower box. 3/16" —> ROUND STICKS TOY MAY BE HEAT BENT INDICATOR lay j HERE SPRING ROTARY ALPHABET WINDOW AND 3 LETTERS Installed over a heating or ventilating grill, this colorful pinwheel provides an interesting toy for small children and at the same time shows the amount of air circulating through the room. Cut the blades from colored paper and glue to a cardboard hub. Assemble the propeller to the end of a 3/16” dowel with a pin. This ingenious spelling box pro- vides the growing child with a toy that has a consid- erable educational value. The box, fashioned from ply- wood as described above, contains five discs on which are painted the various char- toa ei acters in the alphabet. A -—— e The discs revolve on a Any small child would be proud to own this clever little play-horse. All materials dowel shaft fitted with necessary for its construction can be found in any home workshop. The body is a small wooden knobs which length of floor beam cut and planed to the shape shown, while the legs are salvaged project from the ends. A from an otherwise useless chair. Cut the head and saddle from pine stock and make friction drive provided by the tail from a length of frayed manilla rope. Complete the horse by mounting it on the two light springs on a suitable base, fitted with small wooden wheels, and paint it in bright colors. each end of the dowel and the rubber spacer washers be- tween each alphabet disc per- mits spelling any 5-letter word. i4 1/2" FASTEN LEATHER STRAP WITH 4 BLACK UPHOLSTERER'S TACKS | -=— CHAIR LEGS | SCREW LEGS IN Æ FROM BOTTOM LONG NAIL WITH STRANDS [ FRAYED OUT © A ARERR 7 pully, 1937 | z5

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woe ee Fy m p P AU CF A a MPI m NNT O n e L- Aom ou ae Powered by a mini- ature gasoline en- gine, this realistic model will thrill you with its flights. The large wing sections of the Bellanca gasoline-pow- ered model can be re- moved, enabling the craft to be carried to the flying. field in a convenient manner. Fred C. Tuxworth, of Huntington, Ind., who ; designed the model, shows nie the method of carrying it. 3 e Dada ed jè t aata le hand anl OO a uild A Bellanca by Fred C. Tuxworth PART i HE gasoline-powered model deseribed here is a scale reproduction of the Bel- lanca Skyrocket, a six-place ship powered by a Pratt & Whitney 550 h.p. Wasp. This ship lends itself admirably to model building. Its 7’ 542” span and narrow chord wing, large tail surfaces, lift-type fuselage, lift-type struts, streamlines and characteristic airfoil section insure good stability along all axis. Because of its structural arrangement, the construction of the model is simple, differing very little, except in size, from that of de- tailed rubber powered models of the scale flying type. The original model was designed and built within three weeks. This was made possible by the simplified fittings and the methods used in construction. However, since com- pletion, the model has undergone several minor changes, receiving more strength in scme places and a reduction in weight where strength had originally been over-empha- sized. As a result, the model presented is a “tried-till-proven” one. By adapting the mctor mount to its dimensions, any engine of one-fifth or one-sixth horsepower can be used. By following the methods explained here, you can build this model in a minimum of time and at a minimum cost. One of the time-saving tools used in con- struction was a piece of white pine approxi- mately 34” by 3” by 12” to which was fastened, by small tacks, very coarse sand- paper of the type used on large power- sanding tools. This made it possible to sandpaper many parts only partially shaped while assembling. This not only saves time but improves the appearance of the model generally, as all joints should be gone over before the fuselage and wings are covered. Almost all of the parts can be cut from a plank of hard balsa wood, except where otherwise specified. You can have the cutting done at the nearest lumbermill for a surprisingly small cost. A small, home-workshop circular saw, Modern Mechanix Sen wee, ‘eather r a Titiak e a ar aar eae

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wll hl CY “Gas” Model Plane

a _a— ADJUSTABLE AILERONS SLOT IN BALSA COVERING TO a oa ES SUPPORT SPAR REAR SPAR COMPRESSION TRUT

SOLID LONGERONS FWD. OF SPLICE TRAILING EDGE

BALSA LEADING me ne sa aaan Ss S rr T3 p P a a ED SAS aS an Pee EDGE HOLLOWED = >] aS Yiz E FAIRED WING STRUTS y% a ? S

BAFFLE MOTOR BEARERS Z REAR MOTOR ZZ BEARER BULKHEAD | CUTOUT FOR COWL AT TACHM’T. BLOCK | SKID & WEBB BUILT UP DETACHABLE N.A.C.A. COWL a TEMPLATE OF FIREWALL BULKHEA LINED INSIDE WITH .OOS" SHEET ALUM.

~ ` if available, is fine for this. If you wish, you may also make your own glue—one part of clear airplane dope to one part of alcohol, with enough celluloid (old airplane wind- shields) added to thicken it. This will do fine but will not dry quite so rapidly as the commercial products. The fuselage is undertaken first. It pre- sents no unusual difficulty but does, however, necessitate careful construction and study of the plans. The forward part is much more strongly constructed than the after part. This is natural because of the more extreme forces it must sustain. The fore end of the lower longerons, to which the landing gears are at- tached, is of basswood. cut as shown, and the fore part of the upper longerons is cut from 7s” hard sheet balsa. The after end of both July, 1937 FACILITATE ADJUSTMENT OF SHEER PIN TUBES WHEN RIGGING THE WINGS \

BATTERY SLIDE COIL AND CONDENSER ARE ` CARRIED ON THIS GUSSET LANDING LEG HINGE POINT sz A BINDBET WEEN HINGES ) “XA\FOR ADDED STRENG Tr WHEELS — 34 DIAM. EXACT TYPE TO SUIT

ZA HINGE POINT - RUDDER é & ADJUSTABLE STABILIZER EN oe WIRE— HOOK TO FiN “NE STABILIZER GOES CLEAR S THRU OPENING IN FIN W WIRE FITTING RADIUS OF ADJUSTMENT FOR TAIL SURFACESA, AF IN r e- =

Mui WAN i i L ` i 4 ` = a a ee tW — ` ; F-

T i A

-I SECTION LONGERONS AFTO 2 SPLIÇE

IAYEN E PIa REKE 3 CAA FITTING ck EEN Vex 2/32" A \ EY) ub eeu eZ, yy) h 3416" SPRUCE DOWEL, 5” LONG Ga

PHONE JACK FOR BOOSTER BATTERIES

PIANO wiRg __ SPRUCE TEn

LANDING LEG 2

The perspective cut-away drawing of the complete medel (above) shows proper relationship of the integral parts. The smaller sketches show firewall bulkhead template and manner of attaching strut braces. Left—-Three-quarter rear view. Below—Sketch of motor mount details.

REAR MOTOR BU LAHEAD FIREWALL BULKH’D LINE GO 1/4" X 578"

er ere

af 3-PLY BASSWOOD < STIFFENING PLATE | —SECURE TOBEARER WITH GLUE AND BRADS 3/8" X 5/8" A BASSWOOD | J CONSTRUCTION AD DETAIL- MOTOR MOUNT ZA <a a ie ~~ “I “I N 2 Sa

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mm. =) yi : HARD BALSA THROUGHOUT NOTE: UNLESS OTHERWISE INDICATED I" 24 k] — || = 7 H en 3/16" X 1/8" FAIRING STRIPS rs == * a fel) RA oe i l | -aik 4" 4a | 5 FORMERS CUT | (LANDING LEG SEE DETAIL ®@ FROMV/8"SHEET| ` STOP BLOCK OF SPLICE ; : TOPALAYOUT LINE : 5 I/86" DIAM. | STABILIZER APPROXIMATE |5, SEE DETAIL OF PORNERNING | DRILL ROD | FITTING BLOCK | DIMENSIONS it SIDE FAIRING 2% WING POSITION LONGERON SPLICES |, SEE DETAIL | | TO UPPER J43" 34 SEE DETAIL 33 gr OF COWLING i 7 51" \LONGERONS / 16 2 63 8 BALSA FILLER NOTE: THESE DIMENSIONS TO LOWER LONGERONS SEE DETAIL a OF JOINTS a ` SEE DETAIL OF WHEEL MOUNTING FAIRING FORMER © TAIL POST « = 9 > BUILD UP WITH SOFT BALSA AS REQUIRED TO MAINTAIN CONTOUR SPRUCE TIP GLUED TO LONGERON BIND WITH THREAD GLUED JOINT CUT TO SHAPE FROM 5/16! SHEET BALSA DETAIL OF LONGERON JOINT UPPER SPLICE AT STATION #6' 5/16" SQ. (“Sun A E E OL BALSA 178" PLYWOOD (BASSWOOD) FIREWALL. CUT FROM 1/4! SHEET BALSA- DETAIL OF FWD. LONGERON SPLICE LOWER LONGERONS SPLICED SIMILARLY §/16" SQ. BALSA THREAD 1/8" X 3/16" NOTCHES- SPACE EQUIDISTANT LY DETAIL OF BOTTOM FAIRING CONSTRUCTION WIDTHS & DEPTHS TO SUIT STATION- SEE FUSELAGE SIDE VIEW — || FORMERS REQD. 8" X 1/8" H. BALSA DETAIL OF JOINT BETWEEN ANGULAR i y oh LONGERONS AND COMPRESSION STRUTS DETAIL OF SIDE FAIRING FUSELAGE DETAILS 78 402"- TAILPOST TO FIREWALL FRONT SIDE VIEW OF FUSELAGE —SHOWN IN LONGITUDINAL SECTION THROUGH g HY oe ae at oO Ja ee ee Rens EP AÈ Fal = RT SON SH ae _» —— Te rH PeSrittina wei ne | ie Gusser / 33" See af 5/16” SQ-SPRUCE ER PIECES $ KST FORM era a, D S) Dera, es DIMENSION a ni] AT #7 IN eet | AT #8 AT#6 i o ENI j na z i 74 # 40 LINEN THREAD, 5 STRANDS = S) SEE DETAIL OF SPLICE BOTTOM TRUSS PLAN ~S) CELLULOID GUSSET AE ‘ Pi Poor AI BASSWOOD A — y WPA OFF BALSA SIDE A ZAK FORNER TO SUIT ea Ky } 3/4" BRAD 2 BALSA : ETAIL OF SPLICE AT #7 NOTE: STRUCTURE SAME AS TOP FROM STATION #6 AFT- FAIRING STRIPS NOT SHOWN HERE FOR SAKE OF CLARITY Completed fuselage (left) is sturdy in construction. Above— Fuselage layout diagram. Hard balsa is used throughout ex- cept where otherwise indicated. Lower left——Fuselage details. upper and lower longerons is of angle section to provide greater area for the glue joints. Splice the longerons and assemble one side of the fuselage on a full size lay-out using brads for a jig, and with the inside of the framework facing upward. While it is still in the jig, each bay in the after end of the frame should be cross-braced with five strands of No. 40 linen thread. This is done by pressing and gluing pins in the end of each of the cross members and lacing the thread around the pins. The thread is given several coats of dope and when dry the pins may be cut off 4%” from the members. When the whole assembly is well dried, remove from the jig and turn it over, so that now the outside of the frame faces upward, then build the other side of the fuselage on it, again using brads to keep them alike. When the sides are finished, join them with the top and bottom members in the usual Modern Mechanix

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ACTUAL LOCATION OF THIS FORMER I/2"” FWD. OF STATIONS

DETAIL OF SPRING CLIP BEND FROM .020 GA. PIANO WIRE

[V2 LENGTH OF ORDINARY SCREEN DOOR SPRING STOP BLOCK

HINGE POINT 1/32" SHEET

HATCH FITS SECTION _ UP AGAINST THRU HATCH __ ° THIS FORMER a3 46 @ T-8

SCALE IN INCHES SECTION THRU FUSELAGE AT STATION NO.8*SEE CONSTRUCTION DETAIL BELOW

1/8" 3-PLY BASSWOOD SS OR PINE =A O

Ca f dh | $ : RA, MEER NS N | OS™ VS : Sr > FIREWALL Se 5 X 1/20" SHEET BALSA

HARDWOOD BLOCK LET INTO 1/4" BALSA FORMER F | ER FOR SCREW HARD ALUM. HATCH CLIP CONSTRUCTION DETAIL LOOKING AT STATION # 8 manner. The spruce bottom members, im- mediately fore and aft of the landing legs, are joined to the longerons by one-inch brads. Pins and cement will do for the joints of balsa cross-members and solid longerons. The fire wall, of basswood plywood, is held by screws and glue to four small pieces of spruce, which are in turn attached by glue and thread to the frame, as shown in the drawing. The landing gear legs are made and at- tached next. They are cut from basswood with a jig saw and faired with balsa. The hinges, which were purchased at 5-10c store, have the pins pressed out and a piece of 4%” drill-rod substituted. The landing legs are detached by removing this drill-rod pin and the shock absorber springs, which are sec- tions cut from a screen door spring. Screws and glue hold the hinges in place and the longerons are bound afterwards to prevent splitting. Be sure to use at least =” diameter July, 1937

57/16" BASSWOOD HARDWOOD BLOCK TO RECEIVE CLIP

he te pe Pe Koa A AMR VE RA Tr ET oem. digr. E NANA - - ~

1/4 X 5/8" STOP BLOCK SUPPORT PIECE RUBBER PAD _.. 3/32" X 3/8" ti F.H.SCREW Ail

SS LOWER LONGERON

£ HINGE DETAIL

1/8".SHEET BALSA SAND TO STREAM- LINE FORM

COILEDIRON WIRE SPACER CLOSELY

BIND 1/16" BETWEEN EACH WRAP

CEMENT TOGETHER

CROSS-SECTION THRU LANDING STRUT A-A

— SLIP UNDER a ; BOTTOM STRUT s FIBER TUBE ü RUBBER Iae mu E

BANDS PT

K 5 * z. OE -

ee HARD ALUM. CLIPS. BIND TO SLIDE BOTTOM AT EACH END V8" SECTIONAL VIEW (LENGTH 14 TO ISIN) 5/16" DETAIL OF BATTERY SLIDE

A scale pattern for making the landing gear struts is shown in the top-center drawing. Method of hinging and attaching to fuselage is shown in other drawings. The details of the battery slide-holder are shown in drawing directly above, spring steel for the axles. These are bent to shape and ground, so that they will be flush with the grooves cut for them. Pneumatic- tired wheels should be used to insure shock- proof landings. When the basic fuselage framework and the landing gear are completed, the motor mount should be undertaken. The bass ply- wood is secured to the basswood skids with glue and %” brads. The motor bearers then are attached to the fuselage as shown in the drawing, glue and brads being used through- out. Use screws to fasten the engine. The placement of the gas tank depends, of course, upon the engine used. The forward part of the fuselage is covered with 1/20” hard balsa veneer. The curved part immediately aft of the fire wall is formed 79 A - -

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FIT IN SOLID BALSA END PIECCS AT ENDS OF HINGED SEGMENT. SOLID BALSA SPACER ; | LINE CYLINDER | || i fj CUT-OUT WITH | banida Sinan i i aa Aa i i hai a A a ; ALUM, SHEET I i 1 | H ) s \ | | | I ficat | | | | A ‘ | ag ty at = \ TOP VIEW AND PARTIAL SECTION pJ SMALL SCREWS HINGE HERE HOLD WIRE CATCH DUMMY VALVE FAIRINGS CARVED FROM 2" LENGTHS OF 3/8" X 172" SOFT BALSA - MAKE I8- SPACE EQUALLY AVOIDING CUT-OUT SPACER PIECES — SHEET ALUM, BAFFLE PLATE - SCREW TO MOTOR BEARER ENDS POINTS OF ATTACHMENT TO FIREWALL. (SEE DETAIL) FRONT VIEW COMPLETE DETAILS OF THE N.A.C.A, COWLING by using a 644” diameter Shown above are ring former which is cut from 44” sheet balsa. Build up to it with blocks of medium hard balsa, and sand to shape when dry. The bottom of the fuselage is covered with x” medium balsa veneer over formers and fairing strips as shown. The hatch in the bottom, for access to the interior, is also veneer covered. This is held in place with very small screws through sheet aluminum fittings. In all cases when a screw is to be removable, use a basswood block to receive it. The celluloid for the windows and wind- shield and the rounded wooden strips on the fuselage sides are not put on until the fuse- lage is covered and ready for finishing. Easy access to the power plant is obtained by providing the N. A. C. A. cowling with a hinged segment. The construction is simple. The curved forward former is made from several blocks of balsa, cut as shown in the detail, glued, and then finished to shape. This is connected to the rear 1⁄4” balsa ring former by seven pieces of 33” square balsa equally spaced, with a solid block of balsa at top 80 the engine cowling, which is hinged at the top, making the engine readily accessible for minor adjustments. baffle plate adds to model’s appearance. qi CUT OUT LATER TO 6s SUIT MOTOR USED cs one ae “~~ 5/16" SQ. SPACERS METHOD OF BUILDING p ! UP NOSE RELIMINARY CONSTRUCTION PINS FORMER SMALL WOODSC REW LINE WITH 005" SH'T. ALUMINUM BEVEL TO FIT SPACER S/A6" SQ. E] hi4" 3-PLY i6 he | 4 WUA n ne PROFILE SECTION THRU CENTER LINE ATTACH THUS TO FIREWALL fe | LIFT HERE FOR INSPECTION BALSA SHEET GRAIN RUNNING FORE AND AFT construction details of (see drawing), and then covered with 3,” hard balsa. The streamline bumps are made from balsa blocks cut to fit the cowling contour. Shaping and sand- papering are done after they are glued in place. The segment to be hinged may now be cut and provided with solid ends to hold the hinge and wire hook catch. A block is placed between the two formers at the top from which the hole for the cylinder may be cut. This hole of course must be adapted to the engine used. The fire wall and the entire interior of the cowling are covered with .005” sheet aluminum held in place by small wire staples and fireproof metal cement. The cowling is held in place by removable screws in three small basswood blocks that are secured by glue and screws to the fire- wall. The baffle in front of the crankcase is cut from the rounded bottom of an aluminum pan and held in place with screws running into the ends of the skids. This baffle plate improves the appearance tremendously. (Concluding installment will appear in August issue.) Modern Mechanix The aluminum a > _ a.

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PROJECTION BOX MAKES SKETCHING EASY SKETCHSCOPE CABINET DESK Be a; 2 ` N N S "SK Drawing enlargements of photographs, cartoons or ! other illustrations is simplicity itself with this unique | ae enlarging device. Consisting of a cabinet fitted with a glass top and a magnifying lass inside, it projects pictures for rapid tracing on the paper placed on top. LTHOUGH the making of enlarged sketches of photographs, car- toons and other illustrations usually requires some artistic talent and the use of a pantograph, such is not the case when a “sketchscope” cabinet like the one here described is used. Containing a projecting device similar to the familiar magic lantern, pictures placed in the bottom of the cabinet are thrown on the drawing paper on the top of the cabinet for quick and accurate tracing to any desired size. The cabinet is built from 34-inch plywood or solid stock to the dimensions which best suit the user’s particular needs. A suggested height for the cabinet is 32 inches with the width and depth left to the discretion of the builder. Fit the interior of the cabinet with shelf brackets of quarter-round moulding to allow for the insertion of the projection shelf. The projection shelf is merely a board which can be slipped into any one of the cabinet’s shelf brackets and provided with an adjustable magnifying lens working in a sliding tube. The underside of the shelf is fitted with two porcelain cleat sockets and tin reflectors. The photograph to be projected on the top of the cabinet is inserted in the ‘bottom, the lights turned on and the image brought into focus for copying. If a thin grade of drawing paper is used the projected picture will show through it with sufficient clearness for tracing. July, 19827 GLASS TOP CORD TO OUTLET f4 SCOTCH TAPE EXTRA SHELVES FOR PANEL. ADJUSTMENTS CROSS SECTION OF PANEL CONSTRUCTION DRAWING ee CARDBOARD DRAWING IN CABINET IS TURNED BACKWARDS OF CABINET Tin Can Creates Smoke Rings ERFECT smoke rings can be produced with this simple device which is formed from a coffee tin. In the bottom of the can cut a 34-inch hole and over the top stretch a tissue paper drum held in place with an elastic. To produce smoke rings blow smoke into the small hole and tap the drum with the finger tips. t, TOMAKE SMOKE » RINGS, FILLCAN WITH SMOKE AND TAP ON WAX DRUM OE aa COFFEE CAN ba) Fill Perfect smoke rings can be formed with this device. can with smoke and tap the wax drum with the forefinger. 81

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Constructed from old auto parts and powered with a motorcycle engine, this tiny car can be built by any me- chanically -minded man for $100. HAT sporting man, after witnessing his first auto marathon, hasn’t wished for a racing car of his own even though he has not the slightest intention of entering it in competition? While the more familiar full- size racer is a costly piece of mechanism, there is the Lilliputian version, which is not only capable of terrific speeds, but which can be assembled from standard auto parts sal- vaged from the nearest wrecking yard at a cost which should not exceed one hundred dollars, including the motor. The “Arlen Special” is an excellent ex- ample of what can be accomplished with a little ingenuity and a few tools. Designed by Don Arlen, a noted Holly- wood stunt racer, this tiny car is capable of speeds exceeding 108 miles-per-hour. It has the distinction of being the first American designed midget racer to re- ceive the official sanction of the A.A.A., an honor which speaks for itself. If you are not already familiar with this midget car, we refer you to the first in- stallment, which appeared in the June issue of MODERN MEcHANIX. For the many Constructed from parts salvaged from the nearest auto wrecking yard, “Arlen Special” offers the auto racing fan a real chance to develop his creative talents. Power is supplied to the trans- mission by a motorcycle engine. BUILDING “ARLEN SPECIAL- SIDE RAIL PLACE DRAG LINK BALL. N NM E NN SEM > U7 TAS ts FLATTEN AND DRILL | = SS FOR '4’ BOLT BALL SOCKET END a OF DRAG LINK A TA DETAIL OF FRONT RADIUS ROD WELD by Manley Mills REAR RADIUS ROD ANCHOR cope MAKE FOUR OF > j STEEL, BEND AND a WELD AS SHOWN WELD ANCHOR eZ BOLTS TO TUBING eg Cg DETAIL OF REAR RADIUS ROD n 3/, 18 GA. TUBING

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; Se A b = xa he Hh pe OEA Eoee WA. ray we yh he baby~auto fans who have already started” building the “Arlen Special,” no further in- troduction to this unique front-drive racer is necessary. And now to continue with the actual building. You have probably assembled the car as you made each part. Now here’s a way to make the front-end assembly: Since the car is a front-drive and the motor is mounted backward, you must turn the differential up- side down, so the ring gear will be on the left side. If you don’t, imagine your embarrass- ment when you find that the car runs back- ward! After attaching the differential, bolt the radius rods to the front axle, and fasten the ball joints to the side rails. Then, install the spring shackles. Now take the spindle shafts, to which the “U” joints are welded, and put them through the front spindle bodies, it being assumed that the bearings are in place. Put the keys in, and slip the front hubs on the shafts, screwing on the nuts and locking them with cotter pins. Bolt on the steering arms. Insert the large splined end of the coupler shafts into the sleeves in the i 4 tala = esa! mi te s ah KANUNA pi e : p es yee! £ z i att, ‘ G > . ae splined part of the universal joints over the differential. Then, slip the oiea guter end of the shafts, and install the Left—-Front radius rods are formed from 3/9" Be Pa te: Se indle-body king-bolts. Finally, attach the gauge steel tubing, rigidly welded. The ends’ "© tie-rod and drag link. are flattened and drilled for fastening to` front v~ ‘ . . sale. The reat rods ace made th ees Regarding the front wheel setting, it has. manner except that anchor bolts are :welded in — already been mentioned that the caster is 2 the ends. Spindle body details appear:“below. ; a sit degrees, which has been taken care of, and A MIDGET RACER Sonna il 5" TIMKEN TAPER BEAR- —1%.—e| ING NO.07024 CUP Aaaa NICKELADIUM STEEL, ; TORA HEAT 3 S S TREATED Bee Te Íe 2.043 |||| GROOVE E EA E EE Le ake } YA BEARING _ PACKING 3 NO.14276 CUP T LY E TEA -FRONT SPINDLE BODY AS Rs sm Zon: TREAT We QU Soin Fee 14138 a A E Y Tp TAG AY ae is bay D TEA 7 a | ri TIMKEN TAPER BEARING ees ys NO. 14276 CUP % SAE n AOT o AO A Ge : al AUSTIN BRAKE FISH PLATE BEARING CHANE NO.07024 CUP iARM REAR SPINDLE BODY se Hg 07098 CONE OON A.L.40 STEEL, HEAT TREATED

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DETAIL OF SPINDLE SHAFT TIMKEN BEARING NO. 7204 CUP | 7098 CONE HUB FITS TAPER / KEYWAY FOR r y. x He KEY \ USE A MODEL"T’ FORD AXLE SHAFT NUT SPINDLE SHAFT IS WELDED TO UNIVERSAL JOINT Form the spindle shaft from a Timken cone and cup and weld it to the universal joint. COTTER PIN BEARING 3 SHEET = WELD TO FIRE WALL CONNECT TO >} CARBURETOR rr, | 3/ Le f 7 Gan A 46 “4 FIRE WALL CLUTCH jj Les A BRAKE l f be SS S y 6 BELL CRANK TUBING DETAIL OF TAROTTLE| Y LEVER f CONTROLA Y LL E DETAIL. OF ACCELERATOR PEDAL __ The center illustration shows the method of installing the throttle pedal on the brake cross-rod. Two ;%;" bushings hold it in position. Make steering wheel as shown above. 84 the camber is zero. Toe-in is 1%”, taken care of by the bend in the steering arms. It is highly important to get the-toe-in and caster correct. If they’re not, the car will wander all over the road at ordinary speeds. And at high speed, it would act dangerously, possibly getting completely out of control. Make the-front radius rods from 34” x 18 gauge steel tubing, welded, with a fish-mouth joint, to the ball-socket ends of a Chevrolet drag link, Flatten and drill the ends for the 1%” anchor bolts by which they are fastened to the front axle. The balls must be located on the side rails in the correct position to give the proper caster setting to the front axle, which is 2 degrees. All large garages have instruments for checking up on this setting. If you'll locate the balls with their center 13g” above the bottom of the side rails, the setting will be correct. The steering gear bracket is cast from bronze or aluminum, or iron. A 1925 Chev- rolet steering gear should be used. It is dis-assembled, the large end of the housing placed in a lathe chuck and the other end turned down to 13” diameter for a length of 144”. This part should fit tightly in the mounting bracket, with the shoulder against the inside, when bolted to the left side rail. Shorten the steering rod to the proper length and make the steering wheel, which is 13” in diameter. The spider is made from ;;” thick crucible steel, or the spider of a large wheel is cut down. Any pattern-maker can make the wood rim. It should be bound with friction The cowl frame, pictured here, is shaped from '2"-20 gauge square tubing. The dash panel is alumi- num and fitted with spark control, oil gauge, tachometer, air gauge, Fahrenheit gauge and A. A. A. seal. Modern Mechanix nee N

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DISC WHEEL (SEE TEXT) 6 STUDS EVENLY SPACED TO MATCH FORD BRAKE DRUM V32 CLEARANCE FOR STUDS — ee — Z A N ZLILA EA pon == = XN y y BEARING ON “21.18, | 14276 CUP 3 n Yj 14138 CONE TTF VY S.A.E (l p a a er en 7 NUT liu py | RAR t = by z t ) ; ia AF 3° > : ~N 3 4 Ya ci ' t g= 7 ES SSS SS IX a 13 USE THIS METHOD ON Yj | REAR HUBS +" This close-up view describes, better than words, the assembly of the front WM Kiplin, — KEYWAY FOR OI Ye, X Ye Xo KEY drive wheel mechanism. The hub, spindle body, axle, king-bolt, uni- versal joint, coupler shaft, spring leaf and radius rod can be distin- guished in their respective positions. 44 WHEEL LOCK NUT (MAKE FOUR) y 4 —— 7 SS MANN NNN MESS eae be 4| aee | Kise Fe HOLES FOR | SPANNER SS ash asa BRAKE DRUM f hi Lh Le wy) SSS DETAIL OF HUB AND WHEEL LOCK NUT I ENG TH PROF Detail of hub and wheel lock nut are described above. Brake drums are sal- vaged from a 1925 Ford to form the novel disc wheel assembly. Rims are drop-center airplane type for 20x4 tires. tape where the hands will grip the wheel. Make the drag link by welding the ball- socket ends of the regular Chevrolet drag link to a piece of 34” x 18 gauge steel tubing of the proper length. The drag link con- necting arm, electric-welded to the lefthand steering arm, is made by cutting off the con- necting arm of a Chevrolet or made in the same manner as the steering arms. Weld a 38” steel rod between the ball end of the connecting arm and the one on the steering arm, forcing a triangular brace. Rear spindle bodies are cast from A. L.-40 steel, heat-treated. Note the depression be- tween the anchor-bolt. eyes to provide clear- ance for the spring eyes; also the “V”-shaped grooves around the inside for holding the felt-packing retainer. The rear spindle shafts are turned from chrome-vanadium steel and are like the front ones except the large flange isn’t needed: [Continued on page 124] July, 1937 a Aa (MAKE FOUR) H. WRENCH SRA FACES MILLED FLAT TO i ERN FIT STEERING KNUCKLES |» | STEERING ARM \ ARM (MAKE TWO) CENTER LINE OF SPINDLE BODY DRAG LINK BaL s% TOP VIEW OF STEERING ARM a — = CENTER LINE OF COUPLER SHAFT were giti STEERING ARM IS BENT AS SHOWN TO GIVE PROPER TOE-IN ES THIS LINE EXTENDED PASSES THROUGH CENTER OF REAR SPRINGS PARALLEL WITH , WHEEL AT RIGHT ANGLES JTO CENTER LINE OF COUPLER SHAFT This diagram describes construc- tion of the connecting arm of steer- ing gear. Insert shows assembly. 0O cn

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Rigging and Painting by Sam Rabl Naval Architect Flying Cloud is so designed that it can be used either as a sailing craft or motor cruiser. When used as a motor cruiser the keel should be reduced as described in the text. Power is supplied by a marine auto conversion such as described on pages 106 and 107. PART III ITH the major parts of the hull com- plete, the fittings may be installed. The chain plates to take the shrouds must be in- stalled before the sheer moulding is in place. The freezing port in the bow well should be cut in and covered with a door of the same material as the raised sheer planking and arranged to swing out so that it will spill water should a wave come over the bow. The companion slide and cover can next be fitted as shown on the plans. A strip of copper should be used to cover the joint on the for- ward end, or many of popular weather-strip sections on the market may be used at this point. Before the interior woodwork is fitted the drains from the cabin top should be con- structed of one-inch lead pipe set as close to the cover board corners at the after end of the cabin as space will permit. The cockpit drains should be made from the same material with a leather flap tacked over their overboard ends to prevent a wave from work- ing back into the cockpit. The rudder is constructed of steel or brass plate with the stock of the same material. If the rudder is of brass, its thickness should be 1⁄4” and the stock of 134” diameter material. The rudder stock is slotted and brazed to the 86 plate as is also the short stub at the bottom of the rudder which forms a pivot through a hole bored in the returned end of the rudder shoe which should be of 1%” brass, three inches wide. If the rudder is to be of steel plate, the stock will be of cold rolled steel bar electrically welded to the blade. The shoe will then be of steel also and the whole assembly galvanized after welding. The rudder stock is carried through the hull, in- side of a piece of brass pipe or galvanized pipe to correspond with rudder metal, screwed into a proper size hole in the stern knee. At the top of the stock there should be fitted a tiller or quadrant, which in turn is connected to the drum of the steering wheel with flexible steel cable. Should the builder so desire a hand tiller may be fitted, in which case the stock is carried up through the after deck. As there will be a reversing gear fitted to the motor, some means will have to be arranged to positively stop the rudder from turning any further than thirty-five degrees each side of the centerline. The spars may now be constructed from Oregon pine or spruce. They are first worked square with all the proper tapers incorporated. After the spars are squared and all humps worked off of their surface they are again worked to an octagon shape. The corners of Modern Mechanix

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COMPLETE Fling Cloud SINGLE BLOC WITH BECKET MAST 3" DIAM. | ee ie fxs AT SPREADER~ TEEN A SPRING STAY >>> l E SPRING STAY ee 1150" LONG PIN TOPIN } OF SHACKLES MAIN TOPSTAY MAINMAST DECK TO WITHE.26'-6" DIAM. AT DECK . 4.1/2" eras i SEN - DIAM. AT WITHE. 2 1/4" EN AEE AEAN URE l) qs DECK TOFOOT..5'-7" #2 sieeaeeu tastes ——\ : SAIL PLAN" Å *SEE THEBILLOF { LONG. TAPER FROM 2 |/2" DIA.AT CENTER TOI 3/4" DIAM. AT ENDS ALL RIGGING SIZES OR SHROUD MAIN BOOM 13" 6" LONG. TAPER FROM 3 [/2" DIAM. TO 2 i/2"AF ENDS MAIN SHEET SLL July, 1937 PEAK HALYARD SHOULDER CLEAT WOODEN BOLSTER TO KEEP BLOCK FREE OF MAST DOUBLE BLOCK WITH N BECKET SEE FIG.9 FOR GAFF JAW DETAIL FORESTAY In this concluding installment, final fittings and basic rigging details are outlined along with suggestions for painting the auxiliary cruising craft. the octagon are again worked off, and finally the spars are rounded. A hollow sparplane will be a lot of assistance in this operation if one can be procured. At least five coats of hot linseed oil should be painted on each spar and after being sandpapered they should be given three coats of good spar varnish. If bright work is eliminated in the construction the spars may be painted. This of course excepts the fore- mast as far as the gaff will travel. This section should be oiled and given a coat of mastine grease. The bands and withes should be purchased before the spars are made and the JIB HALYARD SHROUD a N : wae yh sji FORE -MAST DECK TO WITHE... 20-0" DIAM. AT DECK .... 4 i72" DIAM. AT WITHE ...2 1/2" DECK. TO FOOT... ..5=3* Rigging details for “Flying Cloud,” when used for sailing pur- poses, are shown above. Complete bill of mater- ials listing all rigging sizes and types is avail- able from Modern Me- chanix Publ. Co., 1501 Broadway, N. Y. C.

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8" CHAIN PLATE- SEE FOOT RAILS -| 1/8" MAHOGANY FIG,9 FOR DETAIL COVER BOARDS 7/8" MAHOGANY FAIRLEAD JIB SHEET — r COMPANION WAY COVER SLIDE RAIL- SHAPE FROM | 3/4" X 3" MAHOGANY ree ECONOMICAL X: AEN CANVAS MAST JACKET OR COVER FILL PLATE e S a aas] ti > E ME h r es Oa 8, 6 fy OF WÚ NCN JL ei “= TRAVELER te " MAIN HALYARD = $ bl m G IT PEAK wl SINGLE DECK BLOCK ——> jam aeee a —— . PN he cn —-— i T THROAT # me -a B Tie SPARE CLEAT des W Soe RAN JIB SHEET ——> ee No SS LEAD SCUPPER PIPES TO DRAIN OUTBOARD | r SPARE CLEAT FORE SHEET DOUBLE DECK BLOCK We ree hE TT L" 62 SKENE CHOCKS ; r- as y rk I = tale are CHAIN PIPE TO CHAIN LOCKER ALL 4" APART eg Doe SINGLE DECK BLOCK GALVANIZED MOORING BITT | . states FIG.10 DECK FITTINGS- SHOWING ARRANGEMENT OF CLEATS AND BLOCKS 8" CHAIN PLATE 7/8" X 3" DECKING LAID IN CANVAS 3$ FOOT RAIL 3'-O" 4! -6§" A! æ 6" = 4’ - 6" , Successful rigging depends largely upon the proper THIMBLE placement of cleats and blocks. This deck plan makes SAET clear the proper arrangement of these vital fittings. MARLINE spar worked to a diameter a little larger than the band at the point where the band is to be located. On the masts it is good practice to allow a shoulder at least an | eighth inch larger than the band so that the a ee Ve Ee band will not slip down the mast when the Qt SSS, \| servina $ turnbuckles are set up. At points where the duono a blocks or stays are looped around the mast, ARA SEaMNe T shoulder cleats of hardwood should be fitted. These cleats should be slightly mortised in the mast so that they will not put all of the load on the screws attaching them to the masts. The foremast should have a thin brass SUBSTITUTE | | “OVER | plate attached at the point where the gaff will ye wif swing so as to eliminate wear on the spar at LACINGEYES senco A T Wy wv this point. This plate should be carried at E a TA ww least three-quarters around the mast and 2 REQ'O- FORE & MAIN BOOM tag D nae fastened with escutcheon pins. The center- CONNECTION FOR THROAT HALYARD ES ge Ns line of the plate will face aft. ONUA E SBER R eae | REEND The wire rope rigging should now be made 2 TRY Z eo exc with all ends aloft spliced or looped as re- MAKE. JAWS Cie Fe. of RAD quired. Splicing is highly recommended as L A MOULDING it will give the rigging a professional look. In event of the builder being unable to splice wire rope it may be turned back on itself and served and soldered as shown. All loops 4 wherever fitted should be served with Italian DETAIL AT | yacht marline to prevent wear on the metal Bee- Reene DETALLS TURNBUCKLES | |p and improve its appearance. After the spars are stepped the lower ends of the shrouds and BEADS ae ro | DETAIL Any blacksmith will fashion these rigging fittings stays are spliced to the correct length to fit at a nominal cost or they can be purchased ready ` i Stade from any boat builder’s supply house. Spars the tur nbuckles when they are three-quarters are shaped from Oregon pine or spruce and treated open. This allows them to be set up properly. with at least five coats of hot linseed oil except for ba if i the foremast, as far as gaff travels, which is oiled. No wire should be tightened beyond the point 88 Modern Mechanix apars Hin oe ee ee ee eee o ee -y —_— a |)

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at which it is reasonably taut so as not to set up undue strains in the hull and spars. Be sure that all manila ropes are rove and all blocks shackled or set in their proper places before the spars are sent aloft. All ends of manila line on the boat should be securely served with sail twine waxed with beeswax so that they will not fray out. Here the builder will be able to show his marline-spike seamanship by producing work that the old sailors loved to term “ship-shape and Bristol fashion.” The sails should be of six-ounce canvas and provided with sail covers as the foresail will not be convenient to remove after every run. Khaki sails look well on this type of yacht, especially so if the hull is finished in a dark shade. The sails should be thoroughly reinforced in all corners and the mainsail should be fitted with sail battens. As the sails PLANKING ee CHINE INTERMEDIATE FRAME Ss — JOINT AT CHINE LOG BOTTOM i EE No detail plan for the intermediate frame joint at the chine log was given in past in- stallments. The joint construction, though ex- tremely simple, is shown here for convenience. are in this case auxiliary to the motor they need not be constructed with the precision that is required of racing sails. Strength rather than shape should be the rule. The sails are laced to both main and fore boom with lacing eyes as shown. All halyards and sheets should be led to the end of the raised deck and belayed on cleats as shown on the deck plan. The locations of these leads should be memorized so that even on the darkest night, in sailors’ lingo, you will “know the ropes.” While ordering the running rigging it may be well to include two moor- ing lines of 34” manila, twenty feet long, which should be neatly eye- spliced on one end. The free end should be seized or served. July, 1937 DIAM. BOLT DRILL FOR 3/8" DETAIL OF MAINSAIL HEAD aluminum is used for the pulley and shackle. use‘! in rigging auxiliary cruiser is illustrated at the extreme right. Flying Cloud’s cabin is amply large for bunking craft is cruises. several adults or a small family. This designed especially for inland vacation With the exterior finished we can turn our attention to its painting and finish. There isn’t a prettier job afloat than those whose woodwork is of mahogany finished natural. In connection with this also there are none which occasions more work to keep them looking this way. For the man who has plenty of time and likes to fuss around cleaning varnish and scraping down whenever it is needed, the bright work will have a lot of appeal, but to the man who really wants plea- sure afloat I would strongly recommend fish- erman finish with all woodwork painted. My own preferences would be a green bottom, black hull and buff decks, with all trim painted white. This of course will not appeal to at least half of the people who build this boat and their preference is respected. In any event secure good marine paints which are the cheapest in the long run. Every coat applied to the hull should be sanded and all seams of the planking puttied flush with a good seam compound. Completed, “Flying Cloud” will furnish its builder with endless hours of enjoyment such as only the deep blue waters can offer. Care- ful construction will result in a truly beauti- ful craft that can be looked upon with pride. * 378" DAM, al E J l" STEEL BOLT a lie ICAL BLOCK WITH BECKET Dura! A typical block as SECTION THRU HEAD. Construction of the mainsail head is described at the left. 89

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neal z = Er Toy z =J Af T petal gyen ‘ a a ` aay r= TA BAR FROM REAR FORK CROSS PIECE TO 7 . Y@\ Top OF MOTOR TO GIVE STABILITY . ae BRACE BOLTS TO TOP OF | REAR FORK BOLTS / | : | FRAMEWORK 1172" X 174" STRAP IRON aen, 4 LOOPED STRAP. SUPPORT AROUND FORK BAR > SUPPORTS FOR C STARTING ROD The motor frame is formed from 11⁄2 by 14-inch strap iron bent and assembled with machine bolts in the manner shown. No dimensions for frame are given since sizes of bicycles vary. REAR BOT- TOM FORK “~ O DRILLED Mabe eae tase ge FOR > BOLTING Fs} TO MOTOR 3: BLOCKS — Oe n ALa TER E WASHING MACHINE MOTOR by M. R. Cullen Attachable to any bicycle, this motorized unit pro- vides young cyclists with a novel form of transpor- tation. Speeds ranging up to 15 miles-per-hour are possible on open concrete pavements and highways. STRAP IRON SUPPORT BENT TO SHAPE SHOWN TO FIT SIZE OF BASE OF MOTOR USED. BOLT TO MOTOR BASE FLANGES SS] FLANGED HUB ON FLYWHEEL STARTING ROD h ENAN ánaran a S ed WASHING MACHINE TYPE MOTOR LOOPED SUPPORTS TO STRAP IRON FRAMEWORK a bicycle can be quickly converted into a motorized “tri-bike” to provide new thrills in cycling. Designed especially for young riders the motor attachment converts the bicycle into a tricycle, the power being supplied by a washing machine motor belted to a midget doughnut tired wheel. On con- crete pavements the motor attachment is capable of carrying the bicycle along at a maximum speed of 15 miles-per-hour which is amply sufficient. Where the bicycle is used in conjested localities a governor can be attached so as to keep the maximum speed down to about 8 miles-per-hour. Any standard washing machine motor can be used for supplying the power. Since nearly all of these motors have similar mountings the supporting frame described in the accompanying illustrations can be used with any motor with only slight changes in construction. Slight changes that may be required for the particular motor used will make themselves evident during con- 90 WIRE !S TIED TO LEFT PEDAL FLANGED PULLEY WHEEL ATTACHED TO SMALL AUTO WHEEL MIDGET AUTO TIRE Power is delivered to the doughnut wheel by means of the pulley arrangement described here. The “Tri-bike”’ is set into motion when the starting rod bar is pressed. The small pulley takes up the slack in the drive belt. Modern Mechanix aan E

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Shown here is a head-on view of the motor unit after being installed on the bicycle. The motor can be started either by pedal or with the kick starter located in the rear. SHOWING CONSTRUCTION OF FRAMEWORK WITH MOTOR BASE AND STARTING ROD AXLE BEARING BEARING BOLTED TO BASE OF FRAMEWORK The simplicity of the starting rod and motor frame is made evident in the upper perspective diagrammatical view. Below it is shown the axel bearing assembly which can be fashioned from materials available at any automobile wrecking yard July, 1937 ; À 4 E n bói i i lll Pee a «2 "aa le n eel BELT) struction and can be adjusted accordingly. The motor frame is formed from 1% by 14-inch strap iron. No dimensions are given for its construction since its size depends largely upon the bicycle and motor used, as previously mentioned. First form the main “L” support which clamps to the bicycle just under the rider’s seat and extends down to a point slightly below the bottom of the rear fork. The axle supports are made next. These consist of “U” shaped brackets bent as illus- trated and fitted with bearings for inserting the axle for the doughnut tired wheel. The “U” brackets are bent to the width of the holes in the base of the motor and the flanges drilled at each end for inserting the mount- ing bolts. A loop strap is bent around the lower fork and attached to the “L” bracket with a stove bolt so that the assembly is sufficiently rigid. An additional bracing bar is connected from the seat bolt to the top of the motor to further strengthen the motor attachment. The power take-off is next given consideration. Referring to the accompanying 91

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Since it is not necessary for the rider to maintain his balance, the ‘‘Tri-bike” is safe enough even for small children. This young lady demon- strates the method of stopping, by applying the coaster brake which releases the tension on the belt as soon as reverse pedal pressure is applied. illustrations it will be noticed that a friction belt drive is used to transmit power to the doughnut wheel. This necessitates the use of a flanged wheel mounted on the inside of the pneumatic drive wheel for attaching the motor belt. If the builder has access to a wood turning lathe a satisfactory’ pulley can be turned from maple or any other hard stock. Other- wise, a manufactured pulley can be used. In order that the belt clears the tire the pulley should be mounted on a metal collar or mounted to the wheel with bushings. A sec- tion cut from an old auto generator housing, and tapped so that machine screws can be inserted for fastening the pulley to the wheel, can also be used. The assembled pulley and wheel are ready for mounting on the axle. The axle fastens to the motor frame “U” brackets with clamps made from a pair of bearings salvaged from an automobile. After inserting the axle draw the bearing bolts tight and insert cotter pins so that vibration of the motor will not cause Q2 , PULLEY AND AUTO WHEEL ASSEMBLY ROLES IN PULLEY HUB FOR BOLTING them to drop off. At this point the frame should be attached to the bicycle and the motor mounted in place so that the proper tension of the belt drive can be determined. A loose fitting belt should be secured and slipped over the motor and wheel pulleys so that the starting rod can be inserted. Form the rod from a length of %-inch iron rod with one end bent crank-shaped and a small c Mua wooden roller attached so that when it is installed in a pair of loop straps at the front of the motor frame the roller will push against the belt and take up the slack. The opposite end of the rod is bent to right angles and a wire attached to it and the left- hand panel so that when tramped upon the wire pulls on the starting rod, forcing the roller against the belt so as to take up the slack and set the motor into operation. This ingenious arrangement permits the cyclist to apply the brakes instantly without the motor being engaged. As soon as pres- sure is reversed on the pedal the starting rod releases the tension on the belt and the motor idles until the pedal is drawn forward. The simple clamp mounting arrangement permits the motor to be removed from the bicycle in a few moments when not desired. Except for the purchase of a doughnut wheel and tire the cost of materials, if a washing machine motor is available, is slight. In most states the “tri-bike” can be operated without a vehicle license. To determine whether or not a license is required in your state write the Motor Vehicle Department. Modern Mechanix Ps ee VO $ ay 1}

Page 93

ABOUT-THE-HOME HANDIKINKS F PAINT Brush Removes Clothes Shine WIRE brush, purchasable at any ten cent store, will effectively remove the shine from clothing which otherwise would have to be cast off. Lay the material on a flat board and brush over the shine with light, short strokes. Do not brush the material exces- sively or the fabric may be damaged by the sharp wire bristles. After completing the brushing operation clean the treated surface with a cloth saturated with benzine. PIECE OF TIRE CASING ABOUT 2" WIDE Clothes Pins Hold Rugs On Line ey MELE as it may appear, this rug and blanket cleaning kink will prevent a sudden gust of wind from blow- ing them from the line when hung out to air. After throwing the covering over the line clip the two sides together with clothes pins as near to the wire as possible. No matter how hard the wind blows, the material will remain on the line without danger of it blowing off on the ground. Housewives usually place the pins over the line, forcing them down over the blanket or rug which results in either the pin breaking or slipping up when the slightest breeze strikes the article being aired. —A. H. Waychoff. July, 1937 Te ee Painting Gadget Made From Funnel HEN using paint directly from the original con- tainer the continual wiping of the brush bristles across the edge of the can results in paint running over the sides and causing considerable smear. A simple and effective way to eliminate this trouble is to fit the can with the funnel gadget shown. Purchase a cheap tin funnel and cut off the spout so that only the upper portion remains, attach spring slips formed from clock spring to the sides and the device is ready for use. The device will eliminate further can smearing. ra n EA ay CHEAP 10 CENT PAINT BRUSH OF ais THE WIRE TYPE BRUSH SHINY SPOTS ON THE TROUSERS, SEAT, KNEES, Tire Casing Forme DoorCheck UTSIDE basement doors that are con- stantly dropping backward, when opened, and straining the hinges, can be fitted with a pair of tire casing catches which will permanently eliminate this trouble. With a hacksaw, cut two 2-inch sections from an old auto tire casing and mount them to the side of the building with long wood screws or nails. When opened the doors engage in the tire casing catch where they are rigidly held until released. BANS, «LAP CLOTHES PIN OVER - THE DOUBLED RUG, SE- SO- LOW THE CLOTHES UNE AGS

Page 94

362 TURN WIND 510 TURNS OF #10 D.C.C.WIRE IN 4 LAYERS WITH 6 TURNS OF WAX PAPER | SETWEEN LAYERS ENDER 4 Above is shown the construction of the reactance choke which regulates the flow of current into the low-frequency transformer. A 5,000-volt heavy duty radio transformer supplies current to the Oudin Coil. The rotary spark gap described at right consists of a slotted copper disc rotated by an electric fan motor. The complete Oudin Coil hook-up is shown below. CHOKE COIL TO LIMIT CURRENT ante eee ee TO 110 VOLTS AC. e 94 POWER TRANSFORMER COMPLETE HOOKUP — meteo mmea — ee oe annus - mecena- p t & & > C aS — asui —^ $ t z ev Fau — T - - * oe by John L. Welbourn EDITORS Note—This equipment is particularly suited for science class-room demonstrations. At no time should a demonstration be attempted by one unfamiliar with the apparatus. Although the giant brush discharge is harmless to the average person, a shock from any part of the equipment other than the high-frequency transformer will carry: with it serious consequences to the person involved. It is suggested that when this apparatus is demonstrated before a group of persons, they be warned not to touch the apparatus and to stand a respectful distance from the low-voltage equip- ment. HE apparatus about to be described is capable of throwing a spark four and a half feet long. In spite of its deadly ap- pearance, this spark is quite harmless. The operator may hold a metal rod in his hand and let it jump to the end of the rod and run COVER WITH 10 LAYERS through his body to ground, not only without vue harm, but without any sensation of shock. BAKELITE TUBE A rather spectacular stunt is to hold one 2" DIA. X 16" LONG wire leading to an incandescent light, and (A Aaa tue bring the other end near the coil. The lamp 3/4" X 16"

will be lighted by the current passing through yee the body and may in a few minutes even be FILL WITH I6” LENGTHS OF #20 SOFT IRON SHIELD CAN y

sinc boeken OR STEEL 2 TEETH 1/2" DEEP UON EREQUENET j D EUENED TO 10" DIA.ON LATHE 5/16"BRASS TYPE OF POWER Ti 3 TRANSFORMER INSULATE FROM 7 MOTOR SHAFT WITH 3” DIA FIBRE CENTER a inate Sue V4"X 4" FIBRE SUPPORTS

CONDENSERS CONNECTED IN SERIES— PARALLEL

HIGH FREQUENCY TRANSFORMER

SECOND.

5000 V.

n7 ROTARY SPARK GAP

GROUND TO WATER PIPE

ean cet lS are eesti ————- —— ee YE EE eee a a ana a ae Modern Mechanix

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SL Ret eae PE Se Lec ey eee WITH GIANT OUDIN COIL POLISHED METAL _-—~ BALL 5"DIA-HOLLOW

burned out. A mystifying trick is to hold a short length of neon tube in one’s hand, and approach the coil. Long before there is any , sign of a spark jumping to the tube, it will PS light with its characteristic glow. 7 Many interesting experiments can be per- formed from an insulated platform. Since the spark jumps to grounded objects, if one stands on a board supported by glass in- sulators (milk bottles will do temporarily) and touches the discharge ball with a metal rod, sparks may be drawn from one’s body by anyone standing on the ground. Care must be taken not to draw sparks from the bare skin, as they might cause a blister. A finger ring, or even a spoon in the mouth, can be used as good contacts from which to draw the spark. A peculiar and weird effect can be had, when one is so charged, by raising the free hand above the head in a darkened room. The person will then be [Continued on page 136]

I" X6" LONG BOLT

GLUE COPPER STRIP AROUND TOP-I" WIDE . SHELLAC WOOD STRIPS, COVER WITH LAYERS OF PAPER BEFORE WINDING ON WIRE WOOD STRIPS I/2" WIDE, 4" THICK, 53” LONG. FASTEN IN PLACE WITH GLUE AND WOODEN PINS J 14-172" DIA.PLYWOOD ~” DISC AT CENTER, TOP, AND BOTTOM OF COIL CYLINDER CYLINDER FORM ¥ 15" DIA. BY 53" HIGH SECONDARY 700 TURNS : | OF #22 D.C.C.SPACED SSS a jli AT 14 TURNS PER INCH SOAK AND SCOUR IN HOT COPPER RIBBON SSS) 9.2 LBS. OF WIRE NEEDED ETNEA a tial a 3/8"X BS SOLDERED ‘i Lo SSS S AA “EMULSION BEFORE USING TO TIN FOIL FOR =. OO RSS AS A PRIMARY-10 TURNS LEADS 7 » a. HH I-72" COPPER li GLASS PHOTO “Sey, ) at rN , RIBBON 53FT.REQD. PLATES 8"x10" A PP “A SSS na a COPPER STRIP i" WIDE GLUED AROUND BASE - WOOD BASE 16" SQUARE HEAT PLATES ion YS > A VEFES EIN | SHEETS OF HEAVY TIN FOIL IN CENTER OF ONE oN ars US uN he SSSR P ALI A SIDE OF EACH PLATE . NA aa EAEN ; RRR IIA WooD BASE ~ Og ; — LL AM pe. MOUNTED ON CASTERS

TWO THICKNESSES OF J \ 174" RUBBER BELTING suit a = > =e ooe ai f -1 LSC eee L COPPER RIBEON 2 NEON SIGN WIRE ah GROUND TO WATER PIPE 7 œ~ BIND EACH UNIT WITH FRICTION le TAPE.THEN DIP 2" INTO BEESWAX AND ROSIN EQUAL PARTS BY WEIGHT ON ALL FOUR SIDES CONNECT AS MANY UNITS IN SERIES- PARALLEL AS NECESSARY TO GET BEST SPARK b | N CONDENSER BANK SPACE RIBBON WITH OF i2 UNITS TWO THICKNESSES OF 1/4" RUBBER BELTING

\ i Y FIBRE SUPPORT \

SECTION. THRU PRIMARY COIL The Oudin Coil is assembled in the manner described above. Condensers are made by sandwiching tin foil between glass plates which are connected in a series-parallel arrangement. To prevent voltage breakdown, submerge condensers in oil. July, 1937 95

Page 96

Home Repair Problems That LOGGED drains, faulty gas burners that

REMOVE RDENED need cleaning and adjustment and dirty N i GREASE OR : GE chimneys are a few of the common house- WITH BAKING ory hold problems which confront the home- ON A ND eS à ; OR BY, SOAN KEROSENE TE ~ =) maker at some time or other. In every in- stance these repairs are simple enough for anyone to correct without the use of special tools. For example, the unsightly grease that collects on enameled ranges can be removed easily with a cloth saturated with kerosene or with a damp cloth and baking soda. Gas burners which fail to burn properly can be restored to proper working order by re- moving from the stove and boiling in a solu- tion of water and baking soda. Where the burner flame is white the trouble is in the air vent. By loosening the set Waar SOMMERS ON CROP ER screw and closing this opening grad- GAS AND AIR MIXTURE ually the correct flame can be de- Aim ENTRANCE termined. The small holes in the burner should be cleaned from time to time to remove all grease that collects in them. Pilot lights

BOIL GAS BURNERS IN WASHING G SODA SOL- | pE-

Sg « J) GAS AND AIR HEX-NUT NYL” MIXTURE - SET SCREW

FOR PILOT LIGHT THAT p i DOES NOT HOLD IT'S FLAME, CLEAN OUT HOLES WITH HAIR PIN USE HAIR PIN TO CLEAN OUT HOLES IN GAS BURNERS

Following these suggestions the kitchen range can be restored to its original condition. Grease on enameled parts is removed with kerosene. Dirty burners should be boiled in baking soda and holes opened with a hairpin. Adjust air vent for correct burner flame. “SIPHON OUT WATER FROM ee a: BOWL, TRAP AND TANK AEN g OBE w REMOVE OILY RAGS, BOTTLE PULL OUT MAIN ELECTRIC SWITCH

7 D i r i + x Se: | ll ' N Zii Ds A wre OCR

A ty ex 7

ee woe a re re ns ree eal | | A j ati

96 Modern Mechanix

Page 97

D #F J —— ‘ke iv

should be also given this treatment. A bulge in the kitchen linoleum is not only annoying, but damaging to the flooring, itself. Where a section which has been ce- mented down comes loose it can be slitted and glued down with plastic roof cement. Roofing cement can also be used to repair cracked laundry tubs. Enlarge the crack with a chisel so cement can be inserted. Creaking floors can be silenced by driving small wedges between the beams and floor- ing. Rustic furniture can be protected against insects by giving it a clear coat of varnish. When a home is left vacant during the winter drain all water pipes to prevent their bursting. Tanks should be drained as well as all drain traps. Toilet traps should be filled with an anti-freeze solution and the water shut off in the basement where it enters the house. In leaving a home vacant for a period of time always remove old clothing, greasy rags, [Continued on page 134]

A fire screen of heavy mesh over the chimney as shown here will pre- vent sparks from flying and igniting the roof,

PLACE BLANKETS AND CLOTHING IN MOTH PROOF CHESTS

COVER RUGS WITH MOTH FLAKES, ROLL UP AND WRAP IN HEAVY PAPER

oe eee July; 19327

eat 1 A A % l Si Fin ns eee SEO i art r a Z . |

OLEUM CAN BE STUCK DOWN WITH “PLASTIC ROOFING | CEMENT

D rrie ere ees

Loose linoleum can be cemented back in place by applying a ceat of plastic roof cement to the floor in this manner. Where there is a bulge in the center of the floor split linoleum with a sharp knife, apply plastic cement and press firmly into place. - |. a —eeeeete e penarermee ate

`y < -. ene a va i\ RUSTIC FURNITURE CEMENT t hia a LAUNDRY , TUB

VARNISH TO CHECK ENTRANCE — OF INSECTS ~.

Rustic furniture can be protected against bugs by coating with varnish. Cracked laundry tub can be repaired with roofing cement. Below—Wedges driven between beams stop squeaks.

ie / BEAM AND FLOOR TO pec a

- QUIET SQUEAKING FLOORS 7 een = sansa

<7 | BEAM ~

Page 98

This Individuality Table Is A

ant — aaae o

| ee A

- BOOK COMPARTME NT ma l ORANE emm: "378" PLYWOOD - cuT 4 i Lay out patterns for front and back panels on heavy brown wrapping paper using one inch squares for a guide. The style of the table can be altered simply by changing panel designs. ERE is a readily salable and novel project which can be turned out on a nominal quantity production basis in the home work- shop of the hobbyist who would like to make his shop pay dividends. Its simplicity, too, commends it to the newcomer in the home workshop field as no exacting cabinet work enters into the construction. The table is strong and enduring and, while adhering to the fundamental design, it can be produced in a thousand and one different designs. 98

PATTERN FOA CUTTING OF FRONT PANEL— LAY OUT IN I" SQUARES ON WRAPPING PAPER. REAR PANEL IS THE SAME HH EXCEPT FOR THE BOOK | PRA, | | COMPARTMENT OPENINGS “| lim || | | eae |__| OIIE LT a e eee | HA aa TICOTT EOT TT Ee e | vw eee” TTT TT Tr Nee G pC EEE TTT ETT TTT TT Line oF eec The sheer novelty of the latter factor makes the table a ready seller for the customer actually designs his own table. The accompanying illustrations show the semi-finished and finished table. A table of this design is rather pleasing to the eye and its all-around utility is manifold. It is suit- able for use in either a living-room or a student’s room. The racks at each end are just the right size to receive large magazines; the pigeonholes accommodate books and the usual all-fiction magazines while the height of the table, combined with the pattern of

CUT 3/6" SLICE iN) LEGS {3" DOWN FROM TOP, FRONT AND BACK PANELS TO GO = THAU LEGS

a = BOTTOM PANELS —f ~~ 4" PLYWOOD~ CUT 2 ~

EL rr, X 3/8" j Modern Mechanix e a è a I : f s ery ( < ai m eĀa zd- Vom a l a ke fete LAA Be poe Me ee | tes) ie pat spe a) en ieee Be ——F CO

7

Page 99

Profitable Workshop PROJECT by Dick Cole ~— FIT FRONT AND BACK PANELS INTO SLICED LEG TOPS-THEN “\GLUE AND SCREW TOGETHER > `N “Ng END RACKS FOR Sas LARGE MAGAZINES \ ss ee i A irr AASS SS ee Fi FINISH WITH VARNISH, STAIN OR ENAMEL LEG TOP TABLE TOP ra ag A a 7 ‘\ FIR PLYWOOD FOR TOP AND FOR FRONT AND BACK PANELS-OR HARD- WOOD VENEER PANELS FOR DELUXE MODELS PIGEON HOLE BOOK COMPART- MENT-OPENING CUT OUT OF OP PIECE PANEL NO. 8 OVAL HEADED SCREWS. The table’s construction is shown here in perspective form. Fir plywood is used throughout for all paneling although a better grade of plyboard can be employed if so desired. The various dimensions are indicated in the details at right. SEE DETAIL OF FRONT 174" PLYWOOD the front, makes it ideal for typing. The table literally sets in the typist’s lap. 3/8" PLYWOOD i" NO.6 FLAT 1/4" PLYWOOD’ HEADED SCREWS By referring to the plans the utter sim- BOTTOM ) ae , maTi SEE DETAIL I" NO. 6 ROUND plicity of the construction will be realized. OF LEGS r MO B ROUND. Excepting for the legs and the bottom panels, all material is 98” plyboard. Ordinary fir y ERONT VIEW g - plyboard, with a well-patterned grain, will , ye hee ee = | serve very well, but one can use any of the Se =e oe | TEN hardwood veneer panels for “de-luxe” Lae min C | | models if desired. The front and back pieces Pe eee =H l- o] which we will call “panels,” although tech- i sal att Bt em oll nically they are “rails’—are cut from one i "| EASTERED |W piece of plyboard on the bandsaw or scroll- i j | OC RANE ! | saw, as the design demands. The legs are r ' i oe avid ee | slotted to receive the %” panels and held fia Hal a e together in pairs by a cross-panel of 36” Paapaa ee i e ERs plyboard glued and screwed to the legs. This p TOP VIEW July, 1937 99 a T 7 r PAN rr — = y TY - ba ʻ -m Y Y Na 1S y Se eee = es sh. NTR T AUL, Pa" (ie a oie

Page 100

Leer naan oun GO? Gen Sn On Son ee oe me mo eee a EEE See ESR AE hH b= = | || ty NF ett tt tt patio ppt HH H- TRV Ae ees eT Cr ‘tH ett CONST ERE Shiai ph buries ate Y iil LAI S heda A EEE ALE] FEE EERE 7 LIBRARY TABLE PEER FEE THL SUGGESTED HEIGHT 29 AA H TIETE BACK SAME AS FRONT FEATH Cy see app ett bE ee TE pt eon a J ee It TV Lee LET ELE LLL Let Li get C ae pt EL Et Ht tt coe eon Lt tT Eat | kL RET eE Oa LA eee EREE EEE E WT E TE E E E EE ary Pe el EE -N shoin Se AC CCOACEETE eee eLE CCH WOE ee T H- NEE EA T] BEA a CCC Ea ANAE HA T AE NE EEN BOOK SHELF REE YARNS, IN En Herc. e EEEE EE cde aol hdadethathes t ” I ey sed cee eee ate eno eee ee ene a a a nad verdiaeeteaaedaguetianaadied tiamen) mymp Ps w VA Acer LAERE Eae] ers PEE eee P E WEEE EE EEF E ee yH H Po E EEE EENS ERER it ee mone neta ES A am ah PT aoe ISTE a OY LILI E ae TUA E TOTE P bet _| heed Pi TT TY} Fp — 4 coa SEWING E HE | SUGGESTED HEIGHT 27" Ha BACK HAS SOLID PANEL HHH TITT - - tp ce EEE e Ce oe iL e E a FH UN E S MAGAZINES These patterns are only two examples of the many table styles which are possible with . ‘ Rae Both results in light, but very rigid construction. The end panels of the magazine rack and the other cross-panels, which serve as partitions, add further rigidity to the table. The top is of 34” plyboard, but a ply- wood border strip of the same thickness brings the edge thickness of the top to %-inch. It is well to cut the legs from 1” oak, although clear pine will do. It will be noted that they taper from 1% inches at the top to 134 inches at the bottom. In building up these tables on a small quantity production basis it is best to make up the legs in pairs as shown in the details on page 98. These assembled units are standard for a wide variety of table fronts. It will be readily seen how the front and back panels fit into the slots in the legs so that, when they are glued up and screwed in place, a very rigid table frame is formed. Fitting of the cross-partitions and the top finishes up the table after which it is ready for varnish, stain or enamel. Of course the design offered in the detailed plans is only one of hundreds which can be incorporated into the basic construction. On this page several tentative designs, solely to illustrate the far-reaching possibilities of the general design, are shown. The big selling point of these tables is that they apparently are “custom built” at “ready- made” cost. It will be found that nine out of ten housewives have a desire for a special table for some special place or need. By showing these women a number of designs of the “Individuality Table” and explaining that it will be built to their own design, the builder will have no trouble in selling them 100 not be difficult. IC Silea Ii. im, if) q A — the general library and If you are fortunate to own a well equipped shop, the making of the desks on a production basis will Above is shown the cutting of the leg slots on a circular saw while at the right . a band saw is being used to cut ey out the front and back panels. of squares. desk design described on the previous pages. sewing tables involve only simple construction work. the idea. Give them the graph chart like the cne shown on page 98, made full-size on common wrapping paper, and instruct the customer to lay out the front design she wants, keeping the design within the block Then cut out the legs, cut off to height desired and paste or pin them at the location desired. The builder merely lays the prepared pattern on the plyboard and cuts it out in a jiffy on the scroll-saw or bandsaw. If drawers are wanted, a very fine blade is used in the scroll-saw and the piece cut out of the panel is used for the drawer front thus giving an unbroken grain to the front panel. Obviously slats nailed or glued to cross-partitions serve as slide-rails for the drawers. The finish of the table is optional with the customer. Many will want it in natural wood and will finish it themselves to match other pieces. Ofttimes fir plyboard can be secured in a grain which closely resembles plain oak. There is no limit to the variations in con- struction and design of these tables. Modern Mechanix

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ROUND HEAD SCREW —-FILL SLOT WITH SOLDER S oa CUN oS... o Lie Ca D LOU Tia

SPRING BRASS E N?

4 Ye HOLES coy NTER-/# UNK i H INSULATING N BRASS PAPER SELECTOR SWITCH (x fa SOLDER

oe

Selector switches for ex- perimental purposes can be made as described above. Brass paper clips serve as contact points. AUTO HEADLAMP HOUSING BULLET TYPE | SPEAKER | Old auto headlight shells serve as bullet type loudspeaker housings for outdoor use. Fine wire mesh is stretched over inside of lens rim and held rigid by speaker bolts. | 1h ete NEY) EEANN = NEE ka rere. more ALOES aie et cea RE

MIDGET DOUBLE POLE SWITCH OS aN £ ee Ny ANTENNA YA oO ps (a 2 7 / GLASS ENCLOSED Bes CRYSTAL DETECTOR Py \ TUBE BASE

anas tid 3 pron N Ger ee PHONES

+ \ E, 2-CIRCUIT TUNER COMBINATION CRYSTAL-TUBE RECEIVER This unique set permits either crystal or tube detection by a simple throw of a double-pole switch. Mount the crystal on a 4-prong tube base, connecting it to P and G prongs. To use 30 í i , TUBE as crystal receiver throw switch to left, remove NO CONNECTIONS type 30 tube and insert crystal in its place. TO LARGE PRONGS GROUND

N ANTENNA POST _ ON RECEIVER

ANTENNA ELIMINATOR ON RECEIVER / TN Ne ae This novel inductance type antenna eliminator permits any modern electric re- 100 TURNS ceiver to be operated NO. 30 EN. with one connection to COPPER WIRE water pipe. Wind the COIL FORM EXTERNAL coils as described at left J <~ GROUND 8 “== (RADIATOR OR WATER PIPE) Jualy,. 1937 igi Se es eS) me ES ee or a

Page 102

i N e A MIDGET Superheterodyne 102 f ANTENNA -000365 MF EAEN TE e e e am oe tae Sit 00025 eM 6 OHM RHEOSTAT PERMANENT RE kia = 5 A ‘ * GROUND “S .25 MEG. Cut the receiver chassis according to the template at top. Set is wired ac- cording to this schematic plan. The tickler coil is wound on the i. f. trans- former dowel as shown at right. Though simple in design, this 3-tube set provides ample volume to operate a small speaker. .OS -MFD am FD. RES .0008 MFD. ‘400 MMFD. 50,000 OHM VOLUME CONTROL by Bill Bartlett HILE the usual superheterodyne cir- cuit is a complicated, multi-tube affair, difficult for the average amateur to build, here is an effective “super” that is simple in construction and uses only three tubes of the 2-volt type. These tubes give exceptionally good results on the broadcast band. One of the unique features‘of the set is the small number of parts required. The total cost of materials, less tubes and batteries, should not exceed ten dollars. The circuit employs a pentagrid converter type 1C6 in the first stage as electron-coupled mixer. By using a good aerial and an efficient ground, the need for a preceding radio-fre- quency amplifier stage is eliminated. No in- termediate-frequeney amplifier stage is used; instead, the mixed frequency is fed directly into the type 32 detector which is made to regenerate, thus compensating the lack of the i. f. stage gain. The detected signal flows into the type 33 screen-grid power tube, which delivers half a watt or more to the permanent-magnet speaker. The set is built on an electralloy sub-panel, 3” high by 6” deep by 10” wide. The front PEAKER Modern Mechanix = nnii en a i lla

Page 103

FOR TEN DOEEARS panel, of the same metal, measures 7” x 10”. With a panel cutter or an expansive bit, cut a four-inch hole in the center of the front panel to accommodate the large airplane style dial used for tuning. Below this opening, drill a 3%” hole to take the shaft of the dial. To either side, at spaced distances to maintain a balanced panel, drill 1%” holes to mount the regeneration poten- tiometer and the volume control filament rheostat for the 33 tube. The disposal of the various circuit components is so clearly shown that by following the photos, the layout can be ac- curately duplicated. Note that Here is the midget superheterodyne in op- eration. A view of the set, looking down on the top of chassis and showing parts arrange- ment, appears at right. parts are spaced to allow simplified wiring by be- ginners. The antenna signal enters the circuit [Continued on page 126] 50,000 OHM July, 1937 6 OHM RHEOSTAT BATTERY PLUG B+135 C-13.5 C-3 A+3 The radio fan with limited technical experience can wire his set simply by following this pictorial diagram. Bat- tery connections are made to set through a 5-prong plug and cable in manner shown. 103

Page 104

mi th fo Mee, Te ST PP TTT ee em) | re eee ee | ual p my ie ee ee ee ; i ed ae Se se a aa ar Nea RA eee ; rh P by Dick Hutchinson Hammered from soft sheet steel and JHE workshop fan will derive consider- te tek lamp dt able pleasure in making these tapped oe e metal desk accessories which comprise an ot one ae a antique lamp and owl shaped book-ends. The only tools used in _ book-ends are especially appropriate for the making the project. person who reads far into the night. Soft sheet steel and copper are the only materials required and can be hammered to shape on an anvil with an ordinary machinist’s hammer. Except for a pair of tin shears and nail set no other tools are required in the making of these projects. Copper and iron are combined in the construction of the desk lamp, producing a contrast that is un- usually attractive. p . = > D : po See av E > NG $ DRS 2 z TAPPED FOR THE HOME The lamp base is of q” soft sheet steel cut out, as shown, with the tin shears. The i : ; ‘ Aft tti t raising is done from the under side as is the lamp base from described in the accompanying photo- ge NE anar ee graphs after which the piece is turned shape on an anvil ae envi over and the upper corners squared up by fenorna ns ATTACH SHADE HERE 172"SQUARES BLANK FOR CUP BLANK FOR SAUCER BLANK FOR SHADE 104 Modern Mechanix s i +? ( a ` y ul = A oii b4 toe i z K l - j t L p J a é a { vm i S ETE NUIA AE ial tl i Ae eRe erie E m aoza amila ae a Lie a I a) i wanes he Set

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mete lee a ee en ee, ee Oe ee ee ee ee A ae - r L 7 T P n . v7, f í ao nran poss hammering them over the edge of an anvil. 18-gauge soft sheet The lower edge or rim is rolled out, filed off Stee ding to te ten, even and holes drilled for fixtures. plate plans below. A disk 344” in diameter is cut from the same material, hammered into shape and a 7s” hole drilled in the center for the mount- ing screw. The cup is cut from 24-gauge soft sheet copper, hammered on one side and the lines cut in with a blunt cold chisel. Next a 3%” hole is drilled in the center and the piece is bent to shape. The shade is also cut from 24-gauge soft sheet copper, hammered on one side, rolled into shape and riveted together with No. 16 brass escutcheon pins. The shade bracket is a strip of 3” soft sheet steel, 144” wide by 1944” long. Is hammered on one side, drilled oS ks di ale and bent to shape. pee See In assembling, fit a composition fixture a aR ao he t 2a S i ‘2S SA ie eat ` zs + P ES n RT Haf T ACCESSORIES STUDY DESK bushing into the base for admitting the cord and also a button switch. Set the bracket in the center of the base and rivet to the base, then set the saucer in place with the copper cup in the center. Insert a brass fixture bush- ing from the under side and to this screw a candle socket. Run the lamp cord in through the composition bushing, connect one wire [Continued on page 130] Mitta PRI FOR l RIVETS —p 7716 HOLES BLANK FOR BASE WHEN FINISHED Heus NG FOR CORD The owl book ends are first laid out actual size on paper ruled off into 1/2” squares for a guide. Cut eyes from alum- inum or chrome metal and the feet from soft yellow brass, July, 1937 105 i ie ho = >t.’ Wo, Mad So Ya ee ee a beet hee bie oe is i

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"e o dka aa ai is

N CONVERTING an automobile engine for marine use, three things are essential. They are oiling, cooling and a satisfactory reverse gear. With the present high speed motors, driving a boat without a reverse gear is like driving a car without brakes. The following is an outline of a simple sys- tem of cooling and oiling a Model “A” Ford motor and a simple reverse gear built up from scrap parts of Model “T” and “A” trans- missions. I have used this converted engine and gear slightly over 450 hours without a single al- teration or mishap other than an occasional

j WELD WALLS 3/4" HIGH X 4 172" LONG ON. NO. L AND NO. DIPS

SS SAAN

Any boat fan handy with tools can make his own ma- rine conversion. A Model A engine and parts salvaged from junked cars comprise materials needed tor making a serviceable power plant. new lining in the reverse band. Welding is the biggest item in the conversion and should not cost over $12.00. Machine work will be approximately $3.50. The balance of cost will be for used parts from the junk yards. Choose a motor in good condition or have it put in good condition as in regards to pis- tons, rings and valves. First take the regular crankcase and cut along each lower corner and across the front end. Then bend the bottom section down 3 inches at the front and insert wedge shaped strips of metal of the same material as that of the crankcase. This pan will hold an extra quart of oil and allow To convert the “A” engine for marine use, the crankcase housing must first be deepened to allow for motor’s operation at all angles. Weld a 3-inch section to the bottom tapered as shown and replace the oil pump spring with a larger one to hold it in position. Weld metal fins to dips 1 and 2 to distribute oil properly. Details of the water cooled manifold . and oil cooling system are shown below. Note that the gen- erator belt is employed to drive the marine pump. CYLINDER OTTWELEL HEATER WITH ENDS WELDED Bx HEAD UP AND PIPE NIPPLES WELDED IN yeh

; COVER THIS OPENING E IN MODEL A HEAD \/2'' PIPE WELDED INTO PLATE OVER PUMP HOLE ) ~—g— RUBBER HOSE WELD PLATES OVER ENDS WITH 2" NIPPLES ay BELT DRIVES ELT ORIVES MARINE PUMP | |

MARINE TYPE WATER PUMP- CONNECT LOW TO TIMING GEAR CASE

WATER AND SLIP OVER OIL TUBE. WELD SEAM MA INTAKE | 2 OF VALVE a Stups, BACK lass ee S | OF THIS POINT ARE HALV E | ALLOW COOLER TO FiT CLOSE TO BLOCK i OIL COOLER AND \ e E A COOLING SYSTEM

Modern Mechanix -o ai g | fs” "aie ee ee! A T “i F mist) DA les ke m

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= the motor to be set at any angle without the oil leaking at the rear main bearing. Be sure that all pan seams are welded to prevent leakage. The oil pump is left as is, but it will need a longer spring to hold it up in place. Next, the inner pan with the connecting rod dips has 34-inch high partitions welded at the rear of the two front dips, as shown. These come within 1 inch of the sides of the crankcase and allow the dip to fill with oil and flow around the ends to the next tray, keeping all filled regardless of the pitching of the boat. The oil and water cooling system is de- scribed in the drawings. The outside oil return pipe from the rear of the valve chamber cover to the front of the cylinder block is covered with a 24%-inch brass pipe split lengthwise and slipped over the oil pipe. DETAIL OF OPERATING BSW eens ON LEFT HAND SIDE OF CAM » PLATE BAND TIGHTENING oy QUADRANT WELDED TO LEVER OUT -SHAFT y & AND LEVER j A WITH ADJUST- on, ING SCREW & LOCK NUT. ADJUST SO CLUTCH IS HELD OUT WHEN CAM IS TIGHTENING CAM FOR REVERSE TO CONTROL LEVER + REVER SE —— >= The marine conversion reverse gear mechanism is salvaged “€— FORWARD, HIGH from a model T Ford transmission. After machining the vaticus parts as outlined in the text assemble as shown at tight. The housing for the reverse gear is a standard model A type with the hole in the bottom welded shut. A model A clutch housing is cut off 3% inches from rear. A “U” shaped piece of boiler plate is fitted over the assembly with an inspection plate provided for easy replacing of bands. July, 1937 = - ee ee hr N ie a os soe ' WELO Z DRUMS CLUTCH THROW- by A. J. Rankin Ser aes eet eae ee SLEEVE WELDED Epari INTO CAP TOFIT BEARING DIAMETER OAE A INNER UNIVERSAL BALL CAP, WELDED INTO END OF CASE “U" SHAPED BOILER PLATE WELDED To MODEL A CLUTCH. HOUSING. CUT OFF 3 1/2" TO REAR OF FACE BOLT To REG- \, INSPECTION ULAR FLYWHEEL DOOR SCREWED HOUSING, USING INTO END GASKET —_, OF CASE a. AND ADJUSTING FELT WASHER AND __ SCREW WELDED SPACER, HOLDO OIL 7 Ao “INTO CASE MODEL A REAR TRANSMISSION DRIVING PLATE BEARING AND CLUTCH PLATES : ASSEMBLED —————~.— ` AS IN CAR = So =e Ea S MACHINE DAIVING PLATE END TO FIT BALL BEARING TOGETHER intend REGULAR REVERSE ee SENG USED ONLY LEAVE OUT BRAKE __ = to BOLT 2 FLYWHEELS DRUM GEAR TRIPLE GEARS TRANSMISSION SHAFT CUT OUT "T" ery- WHEEL 1/2" OUTSIDE TOGETHER TRIPLE GEAR PINS MoDEL'T” Se, | FLYWHEEL a FLYWHEEL 1/4" MACHINE SMOOTH TO FIT RE- „DUCED MODEL MODEL A FLYWHEEL BOLTED TO MOTOR The seam and both ends are brazed up. This size pipe will take in the bends in the oil pipe, but will have to be fitted before welding. It will be necessary to halve the heads of two of the valve cover studs to allow the cooler to fit close to the block. One 42-inch water pipe [Continued on page 128] 3— 3/8" CAP SCREWS, RECESS OUT 107 ~ fiw = > 1 eee ee ee et ere ee ee á p =

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Long Ropes Remotely Control Garage Doors Any counterbalanced type of garage door can be conveniently opened without This photo-diagrammatic plan shows how ropes and pulleys are installed so as to permit the doors to be remotely opened or closed. leaving the car. Rear Mirror Improves Vision HE driver who is about to make a left- hand turn in congested districts can never be sure that there is not another car just behind him which is trying to pass. Should he suddenly turn the result would be that the two cars would collide, resulting in, at least, torn fenders. Considerable expense and worry can be avoided by installing an inex- pensive rear vision or “header” mirror to the righthand side of the rear window frame in a vertical position. A glance in the mirror will tell the driver whether or not the road is clear. The extra mirror reflects objects not visible in the regular rear vision mirror. The installation of an extra header” mirror on the right side of the rear window of the car will increase the driver’s rear vision considerably. It is especially useful in congested traffic. 108 1c aaa an aa a a T ee E S a NY garage door operating on a counter-balanced mechan- ism can be opened or closed with- out the driver leaving the car simply by installing the ingenious pulley system pictured in the il- lustration at left. By experiment determine the two points on the door where the least effort is re- quired to open or close it and install two large screweyes. Di- rectly over the door, in either the right or lefthand corner of the garage, mount two pulleys and through these thread two lengths of heavy sash cord, anchoring it to the screweyes in the door. The ropes pass through holes drilled in the garage wall to a point which is sufficiently re- moved from the door so that it can be opened while the car is parked in front of it. Carry the ropes over two sets of pulleys mounted under the eaves of an adjoining building or to any other convenient supports. Only a slight pull on the ropes is required to open or close the door. | Parts Tray From Battery Box Worthless storage battery cases can be converted into handy small parts trays for the garage or workshop simply by cutting down the hard rubber case, with a hacksaw, to the size shown. ee worthless storage battery cases can be converted into useful small parts trays for storing nuts, bolts, washers and cotter pins, simply by sawing them down to a height of approximately two inches. Before sawing off the top, the battery case should be washed out thoroughly with soap and water to remove every trace of acid. Unless this precaution is heeded, corrosion of metal parts placed in the tray may result. Since the battery case is divided into three- cell compartments and these into smaller plate compartments, twelve individual parts divisions result. Modern Mechanix

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Preventing Headlight Glare HE annoying glare of headlights from cars approaching from the rear makes night driving hazardous, especially when one is traveling over unfamiliar highways. By cutting a piece of bright wire fly screen the exact size of the rear window of the car and installing it to the frame, much of the glare can be eliminated without affecting the driver’s rear vision. The screening causes a considerable portion of the headlight rays to be reflected back on the road.—C. S. Siddons.

INSERT. IN ENGINE HEAD IN PLACE OF PLUG

SCHRADER TIRE GAUGE

FILE OFF SHOULDER | OF NUT JÉ Nut MUST FIT OVER GAUGE

SCREW NUT BACK INTO BASE OF PLUG BASE OF x aa SPARK PLUG WITH ERN PORCELAIN TAKEN

Ford Coil Starts Dead Motors N EMERGENCY ignition system that will start any “dead” car motor can be assembled from a Model T. Ford spark coil. Solder wires to the primary coil and attach battery clips to the ends. Another wire, fitted with a tip for inserting in the distributor head, is next soldered to the high tension terminal. The coil is then inserted in the box and pitch poured in to hold it in position. To use the coil attach the clip on one primary lead to the car frame, the other to the battery side of generator cut-out and the high tension lead to center contact of dis- tributor.

AS HLN 7 aR AIR. PUMP X AND FAN

PIPE TO CARRY 4 EXHAUST FUMES FLOO n ( F <- P £ I p : M BENER ~ a

OUTLETS AND CON- NECTING PIPES FROM DIFFERE SPOTS

EC FROM EXHAUST PIPES

stele atl! Futy, 19237 D e SOR PS 2 oY OXI SSS OY

PLACE UNPAINTED METALLIC SCREENING OVER REAR WINDOW TO POLARIZE THE LIGHT FROM A FOLLOWING CAR. SCREENING CAN BE FRAMED AND HELD TO REAR WINDOW WITH HOOKS

Gauge ChecksCylinderCompression HIGH pressure tire gauge fitted to the base of a spark plug provides the auto mechanic with an efficient device for testing the compression of auto cylin- ders. Take an old spark plug and remove the porcelain top, then file off the burr around the assembly nut and slide it over the tire gauge and screw it into the larger spark plug nut. To use, remove one of the spark plugs and insert in its place. rises to maximum pressure.—S, Zayets. Turn over engine until gauge —<—— HOOKS FOR HANGING UNDER HOOD A MODEL "T" FORD SPARK COIL HIGH TENSION = WIRE GOING WIRE -REPLACES ___TO DISTRIBUTOR

Draw Exhaust Fumes From Garage ys planning a new garage the professional auto mechanic will find this simple ventilating system well worth installing. Before the concrete flooring is laid, lengths of four-inch iron sewer pipe are connected up into a network with tee fittings installed at points where overhauling work will be handled. The end of the pipe leads to an exhaust fan for drawing out the fumes which pass from the car exhaust pipes. 109

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With the simple copying frame and developing box attached to your camera as shown at upper right, permanent photos can be taken and developed in less than ten minutes. Examples of the negative and posi- tive, both on bromide enlarging paper, appear above and at left. TEP right up, ladies and gentlemen, and have your picture made for a dime. In less than ten minutes you will have an ex- cellent, handsome likeness of yourself that posterity will point to with pride. Or, build this outfit yourself and take pictures for others; 8 cents of every dime is clear profit. If you have an ordinary focusing camera and tripod the cost will not exceed a dollar, which covers the price of a copying lens attachment. These taken-while-you-wait pictures are far better than the dull, lifeless photos made by professional one~minute cameras, which require the use of special chemicals and di- rect-positive paper. Instead of films or plates, the holders are loaded with glossy, medium- contrast bromide enlarging paper. You can make your own regular developer, according to the formula supplied by the paper manu- facturer, or purchase it in 6-cent tubes at any drug store or camera supplies shop. 110 ie, es a a The routine of making a picture consists in the usual exposure, but on the bromide paper instead of film, as just mentioned. It is de- veloped for one minute in a portable dark- room box attached to the tripod and then transferred to a tray of ordinary hypo fixing solution for another minute. After sandwich- ing the paper negative thus made between sheets of glass it is placed in a holder in front of the camera and, with a copying lens slipped over the regular camera lens, photographed onto another sheet of bromide paper to make the “positive” or print. The positive receives the same chemical treatment as the negative and after rinsing in water it is ready for delivery to the cus- tomer. For greater permanency it may be washed for 15 minutes. As many prints as are desired may be made from the one nega- tive. Bromide enlarging paper has about 1/10th Modern Mechanix

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Your camera can be made to take “instant” pictures with this novel process, which does not require the use of films. Instead of filling the camera plate holders with cut film, sheets of bromide enlarging paper are used. Expose film, remove holder from camera and transfer to the developing box attached to tripod. The resulting negative is then rephotographed, by mounting to frame attached to camera, to secure a positive print. the speed of regular camera film and it there- fore requires ten times longer exposure. This does not mean that you must use time exposures, however. On an average bright day, fast “chrome” type camera film would require an exposure of about 1/25th second with a lens aperture of f:16. Keeping this July, 1937 An ordinary folding camera can be used for taking “instant” photos by making a plywood attachment for the film holders as shown at upper right. A large cigar box serves as a develop- ing cabinet. Openings in box are made light-tight with black velvet cloth. a Gt a8! one me wi NOt Pte aa 5 z AOTAN 5 "n ENTE H M yas ote in mind as a basis, you can figure that the bromide paper will require an exposure of slightly less than % second under the same conditions. Likewise, with a lens aperture of f:8, an exposure of only 1/10th second will be sufficient. This compares favorably with [Continued on page 138] 11] oie eT pal oe ere

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This simple plywood box fitted with a brass lamp socket contains two flashlight cells for setting off the photoflash bulb. Mount tin reflector to bulb as shown in circle. HE amateur as well as the professional photographer can get good wild animal photographs at night. The subjects may range from mice and shrews to opossums, weasels, skunks and other nocturnal animals who are rather difficult to photograph in the daytime. In fact, the common house mouse and the alley cat are also interesting sub- jects for photography. The best way to take these pictures is to set a “photoflash trap” whereby the animal, taking the bait, sets off a photoflash bulb with the camera focused on the bait and with the shutter open. The simple apparatus described here is ex- cellent for taking “automatic” pictures of [Continued on page 132] The simplicity of the battery box is shown in the phantom view at right. Cells are mounted in reversed positions in box with a spring clip, sliding board to hold them secure. Leads from the lamp socket connect to thumb tacks on sliding board. 112 l : "ia á å b A? [ià 4 Lé‘ $í a i f ad et Fae Ek a T eA A A a U ee be es Taking night pictures of wild life is simple with this arrangement. Mount a knife switch on stick, baiting it as shown. A slight pull on the bait closes the switch and sets off the photoflash bulb. =——_ WIRES TO SOCKET " __ BATTERIES SLIDING BOARD

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ae OT a aE a = — P i ae wy te UA X . H _ = E p 4 TR EFES w a aes S Y seime TET VEES aa fie z ’ è : . yy ‘ ; ` f - =e Vi A |

mg, 2 s RT i <n E

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RENG AA SS i. nie N ; R i

RANGE FINDER DISTANCES ARE SCRATCHED INTO EYE PIECE OF TELESCOPE

An ordinary pocket telescope can be used as a camera range finder simply by measuring off various distances from an object, bring it into focus with the telescope and enscribing the number of feet on the barrel of the telescope. When taking pictures with your camera adjust telescope until object is in proper focus and note reading.

TOP VIEW

i FILM SPLICER 3/32"HOLE AND EDITING

2 BRACES NEEDED MACHINE SLOTTED EMPTY REEL FOR FILM KIDDIE SMALL AN EMERY ee robe » = i a Designed for home movie fans, this novel film editing machine can be assembled for less than $1. £ ten PANE OF Get a cheap bench grinder, remove the grinding V| GLASS wheel and replace it with a film reel. Mount the - Vy u Ís on ae end of a | pani ans step iron ; HAY PR Wl D racket on the opposite end for the full reel. The i li - \ I met examining device, mounted in the center, consists of | We

BACK- GROUND An inexpensive pocket watch having a second hand can be used for accurate photo de- veloping timing simply by mounting a large reading a “Kiddie Kamera,” such as sold in ten-cent stores. WIRE IS BENT IN FORM NA | RSQ) A

SECOND glass in front of the face. aN ae f na = watch on a stand MIRBOR, a Hi ormed from coathanger wire FOR / Orr in the manner shown at left. NTEN, kenapi IN DARKROOM A projection on the top of BACKGROUND the stand permits the mount- ing of the reading glass. Photographing biological specimens on a natural back- ground can easily be accomplished with the reflecting table described above. It consists of a stand on which is mounted a clear pane of glass for placing the speci- mens. Directly underneath the glass mount a mirror, fitted with a pair of bolts and wing nuts om each end, so that it can be adjusted to any desired angle. To photograph an insect, place it in the center of the clear glass pane, adjust the mirror to the correct angle for reflecting a suitable background and snap the picture. Care should be exercised so that the glass pane does not produce any extraneous landscape reflections.

July, 1937 113

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poe aa es as Te ease + Ly ee eae ee le ee ie Re oe aha N 5 j i = 4h tlh oh m i EAS l ` a) ee E gt Darkroom Aids For Amateur Photographers teu | xx Rack Prevents Breaking ean Bishi T> MAKE a simple, foolproof support for z, ii a glass graduate in the chemical labora- tory or darkroom, cut a U-shaped opening in a block of wood, just large enough to take the thin section above the base and mount this to the wall, preferably under a shelf, by means of two small iron brackets that have been spread open a bit. In this inverted position, the graduate will saanti y ; pti br ji he ; » WOODEN BRACKETS SUPPORT GRADUATES drip clean after being washed, will not gather | dust and will not be knocked over inadver- ore ' tently in the dark. Candle Stops Frilling Of Film Edges EE WITH CANDLE ITH some types of film developers containing a | large percentage of alkali, and especially when the solution is very warm, photographic films are subject to “frilling” or detachment of the emulsion from the cellu- loid support around the edges. This can be prevented by the simple expedient of rubbing a wax candle around the edges of each film before placing it in the developer. The slight amount of wax adhering to the edges prevents the gelatine from becoming too soft. * Newspapers Make Substitute Blotters e newspapers that are a week or more old, so that the ink will not offset, make excellent blotters for drying matte-finish photographs. Glossy prints can also be dried in this way if it is not desired to secure a high-gloss finish. Unlike expensive blotting paper, newspapers do not deposit lint on the prints. In addi- tion they can be thrown away after once being used, instead of being stored and allowed to accumulate dust and dirt. o aE a a ae Soga AN Bent Ferro-plate Dries Prints LOSSY photographic prints show much less tendency to curl if they are dried on a ferrotype plate bent to provide a curved surface. Prints dried in this manner, when compared with similar ones dried on a flat plate, are considerably flatter. The prints are given a backward curl which disappears, leaving them flat or with a very slight for- ward curl. The plate is held in shape by a piece of stiff wire with each end bent to form a hook or by a loop of cord passing around it. 114 Wee toot oe eT oh oo 4 4 g A l f jj *. Dy : RLE D { 7 i 7 a Jie seein OE ee zh | ~~ p í toa. ge eee eel EEC yr To on A hue |

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imme? cu

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Bo val | PHOTO PUZZLERS 3 In this department, the Photography Editor will answer any question or problem relating to cameras of all types, enlarging, printing, developing, taking pictures, and the various phases of home movie making. When sending questions to this department, be sure to include a stamped, addressed envelope, so that we can answer directly in case space does not permit publication of the question on this page. Send all inquiries to the Photography Editor, Modern Mechanix, 1501 Broadway, New York, N. Y. NEGATIVES FAIL TO DEVELOP In my first attempt to develop a roll of snapshot film my results were very disappointing. After the developing and fixing operations the film showed nothing but a dull cast. No images were visible. Before attempting to develop any more films I would appreciate an explanation regarding the cause of the trouble encountered with the first roll. Can you offer any helpful suggestions?—-Stephen Moodovaurey, Ft. Mead, Md. If your films were opaque after being developed they were, in all probability, light struck. It must be remem- bered that in developing films the room in which the de- veloping operation is carried out must be totally dark, except for the safelight and this should be placed some distance from the developing trays. There are several other factors that will result in similar effects. The use of stale developing powders and hypo that has been stored in a warm place will often ruin a good roll of exposed films. Failure to develop negatives for the pre- scribed period of time, dirty trays, insufficient washing and poor work- ing facilities are, all too often, the cause of disappointing results. Be- fore attempting to develop addi- tional rolls of film we would suggest that you procure a copy of the book, “How To Make Good Pic- tures,” which covers the topic of amateur picture making from A to Z. Copies of this 224 page photo encyclopedia can be obtained from the Photography Editor for 50c postpaid. COPYING ILLUSTRATIONS FROM MAGAZINE COVERS Is it possible to copy illustrations from newspapers and magazines with a good quality snapshot camera? At the present time I am interested in making a photographic collection of magazine covers and would like to use my camera for this work if some arrangement for doing this is possible. Any particulars you might care to offer would be welcomed by me.—Harry J. McLatchy, Arling- ton, Mass. Even the inexpensive box camera can be used for copying newspaper and magazine illustrations by fitting it with a copying adapter lens. Since you possess a snapshot camera of the more expensive type it is well suited for copying work. Your photo- graphic dealer can supply a suitable lens for copying purposes at a cost of 50c. ‘The adapter in which the copying lens is mounted slips over the original camera lens housing, the bellows are adjusted as prescribed in the instructions packed with the lens. To make copies of illustra- tions, place the page on which they are printed in an absolute vertical position and the exact distance from the camera lens as given in the in- structions for using the copying 116 received MM?’s $3 AMATEUR PHOTO AWARD The unusual silhouette tree scene, shown at top, was taken against the sun with a camera fitted with a color filter. posure on SS Panchromatic film was used in taking this photograph which won this month’s $5 amateur photo award for Frederick Lloyd of Port Hope, Ont., Canada. picture of a young burro peering into the surveying instrument was submitted by E. C. Romick of Medford, Utah. second prize adapter. Exposures of printed matter can be made by the time or instantaneous methods depending on the amount of light available. A method for making photographie copies with a spectacle lens was described in the November, 1936, issue of Modern Mechanix. For more detailed instructions we suggest that you refer to that issue. REMOVING GREASE FROM MOVIE FILMS Do you know of a solution that will remove grease and dirt from home movie films. After the reels are used several times the oil from the claw mechanism gets on the film and a considerable quantity of dirt particles collects on the surface. These particles naturally show up on the projected pictures and prove very annoying. Is there a preparation on the market for removing the accumulation of grease without harming the emulsion?— P. M. Ohlinger, Portsmouth, Lowa. Grease can be removed from home movie films by applying carbon tetrachloride or alcohol to the affected surfaces with a soft cloth and rubbing away the grease de- posits with light, even strokes. If handled carefully, the cleaning solu- tions mentioned will have no harm- ful effects on the emulsion. STRENGTHENING WEAK NEGATIVES I have a number of negatives that produce very weak prints. Inasmuch as the subjects are highly valuable to me I would like to secure better prints if this is at all possible. Would the use of a very sensitive printing paper give me the desired results or must the negatives be treated in some manner so as to pro- vide more contrast?—Arnold Kay, Mt. Penn, Pa. Weak negatives can be intensified, so that satisfactory prints can be obtained, by re-developing. Place the films, first, in a bleaching solu- tion for one minute then remove and wash thoroughly in water. Next, place them in the re-developing powders solution, which your photo shop can supply and allow them to remain in the chemical bath for one-half minute. After removing from the re-developer, place the films in a hardening solution for five minutes and finally wash off all traces of chemicals with clear water. The films, if thus treated, will show a decided increase in contrast so that good prints can be made from A 1/50 second ex- hens. The photography editor will pay $5.00 or $3.00 each for photographs interesting enough for publication on this page. All pictures should His snapshot be mailed to Modern Mechanix, award. 1501 Broadway, New York, N. Y. The amusing

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ee a Ty CED. T Inexpensive, Simple to use—and how they step up your Picture-Taking Skill Light, compact, rigid; fit any standard tripod socket. Sec- tions telescope neatly to give small collapsed size without sacrifice of strength. Three The ordinary hand camera is not dee- signed to take pic- tures at extremely short distances. But a Kodak Portrait Attachment slipped over the lens of your Koda k or Brownie keeps the image sharp. You can make ‘‘olose-ups’’ of your family and friends, as well as clear-cut, close-range pictures of flowers, art ob- Taca eN, KODAK METAL TRIPODS KODAK PORTRAIT ATTACHMENT Slipped over your regular lens, it holds back the light from the blue sky, and gives you beau- tiful cloud effects. The darker portion of your picture, the landscape, gets full exposure. Price, de- pending on camera, $1, $1.50, $3.30. and still-life subjects in general. jects, The attachment slips quickly over the regular lens. And the camera is operated as usual. Price, for most cur- rent camera mod- els, 75¢. models, ranging from 1314 to 154 inches long, closed. Nos. 1 and 2 have revolving heads; camera may be swung in any direction. Prices, No. 0, $2.75; No. 1, $4.50; No. 2, $5. Rubber tips, to cover metal spurs for indoor use, 10¢ for set of three. THE KODAPOD Toothed jaws grip tree or fence, other end threads into any standard tripod sock- et. Clamping screw adjusts camera to Holds back blue and violet rays reflected from highly colored landscapes, gives weak- er shades time to regis- ter. With it black-and- white pictures render ali colors more nearly as the eye sees them; they're more natural. Price, depending on camera, $1, $1.50, $3.30. KODAK ADJUSTABLE eS D Prevents “‘lens flare in ee light, in making oo back-lighted shots. Two sizes, 85¢ and $1, depending on diameter of lens or lens attachment over which hood is to be used. KODAK SELF TIMER Lets you get in the pic- ture yourself. You clip it to cable release, set it, and, in a sufficient time interval, the shutter is automatically tripped. Price, $1.25. Cable release (specify name of camera) 35¢ additional. KODAK POCKET RANGE FINDER Used with any camera that has a focusing scale. Look through the eyepiece, turn the knurled ring until the two halves of the image are perfectly matched, and there’s your correct distance, indicated by a pointer. Set for that dis- tance, and sub- correct position. Car- ried in coat pocket. Price, $1.75. ject is in focus. Spring pocket- clip. Price, $7. SEE THEM AT YOUR DEALER’S Eastman Kodak Company, Rochester, N. Y. When Answering Advertisements Please Mention July Modern Mechanix 117

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Carleton Ellis, Chemist [Continued from page 57] of providing the money to carry on his investi- gations. The first profitable invention made by Mr. Ellis, conceived at the age of about twenty while on the instructing staff at Massachusetts Institute of Technology, consisted of the paint and varnish ` removing compound as sold everywhere today. The reason he invented it: he was determined to start up some business in which he would be his own boss and do the work he dearly loves— that is, delve into chemical phenomena. Carleton Ellis is a living example of what one can accom- plish in the fields of science through independent, personal effort. Chancing upon a workman removing paint gave Ellis the idea for his paint remover. The work- man first scrubbed the surface with caustic soda; it removed the paint but left the wood dark. Then he proceeded to bleach the wood with oxalic acid. “Here is an opportunity,” young Ellis said to himself. “Ill concoct a chemical which will permit removal of the paint without discoloring the wood.” And he did it. Under an old shed, with three barrels for equipment, and a borrowed $500 for capital, Ellis began manufacture of the compound, while two of his college companions sold it from place to place. While operating under such limited ca- pacity an order came from the Pennsylvania Rail- road for a carload of the Ellis paint remover! A perfect paint and varnish remover was the object of Ellis’ early research, for in those days most coatings were short-lived and required fre- quent renewing. Now suppose, the young chemist reasoned, someone should perfect a durable coating material, then the demand for my remover would collapse. Why not play safe and go to the heart of the problem by improving the paint itself? Perhaps a lasting paint could be developed with less effort than a perfect paint remover? Time has revealed that the young chemist did not realize the gigantic task he was laying out for his goal. Though in thirty years, Ellis has made many improvements in paints and lacquers, the effect of which has revolu- tionized the industry, what he considers the perfect paint has not yet been found. Without wincing he continues his search. Having tried all known natural oils and resins without obtaining a perfect paint, Ellis resorted to making resins synthetically—making com- pounds which nature has never brought together in just the right proportions and conditions to permit chemical union—in the belief that he thus could obtain products superior to those of nature. Running anywhere from ten to twenty new synthetic resins and compositions daily, Mr. Ellis has produced well over 100,000 new products. Yet the end he set as his goal has not been reached. While his synthetic creations give an improved paint, out of the entire lot there is not a single compound which he considers perfect. 118 — > If the compound possesses the necessary hard- ness, perchance it may be found too brittle or incapable of withstanding. heat; if it be moisture proof, perchance it may lack color appeal; if it is easily workable, perhaps its cost is prohibitive. To convert waste and cheap materials into new and useful things requires true genius. While in Germany Ellis was shown stored 50,000,000 pounds of synthetically made urea, a chemical having the appearance of salt. It was being sold for fertilizer, but the market was slow. Ellis had been thinking of a new use for it—urea formalde- hyde is the result. Ellis made this important plastic or molding material by mixing four familiar colorless gases—ammonia (used about the household for cleaning), carbon dioxide (which we exhale), carbon monoxide (which automobiles exhaust), and hydrogen. “Why, I consider that almost a miracle of creation,” an awe-struck guest remarked after witnessing the process. Today urea formaldehyde may be seen at every hand; for example in toilet articles, clock and radio cases, dishware, tiles, and buttons. Because it is non-inflammable and non-fading while available in a wide range of brilliant colors, it has about supplanted celluloid except for photo- graphic films. It has largely taken the place of hard rubber. Several corporations now market urea plastic under license of Elli? patents. “This is all a good point for young chemical inventors to note,” said Ellis. “Business sense is just as essential to the successful professional inventor as is enthusiasm for research.” The dog biscuit is a case where Ellis turned waste into a profitable industry. Seeking a use for the waste products of his industry, the owner of a slaughter house once called upon Ellis for help. After reflecting, Ellis mixed the waste with malt and other healthful food ingredients, and baked it into nice flat cakes. To his dismay, Fido would have none of it. “So I baked some more of the same stock, but in the shape of a bone,” Ellis relates, “and I found that my dog manifested a tremendous interest in the bone- shaped biscuit. To this day I cannot tell whether my dog is interested in the bone-shaped biscuit because it fools him as such, or whether, after my shaping the biscuit in an effort to cater to his taste, he feels duty bound to fool his master by simulating an interest in it. In any event, the artifice works, and that is the true story of the start of the dog biscuit industry. Mr. Ellis has performed magic in the field of petroleum. One of his outstanding inventions in this art was the development of the “Tube and Tank process” of cracking oil used by the Standard Oil and other leading companies. Mr. Ellis has done much in developing a Diesel motor fuel suited to the Diesel operated streamlined trains and Diesel propelled boats. He took paraffin from petroleum, converted it into a fat substitute and then made soap out of the product. Believe it or not, the soap will lather [Continued on page 122]

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i e a I = Eo | ae A = hom im | ee Ti eo I a ee =e The world’s most accurate gages insure the precision of GENUINE d FORD PARTS Y sinnani Inspection gages of all types are set accurately by means of Johansson Gage Blocks at the Ford Plant in Dearborn, Michigan. Precision manufacturing is one reason why you can depend upon Genuine Ford Parts to hit properly — to last longer. For example, you can depend upon camshaft bearings and push rods to measure within five ten- thousandths of an inch (.0005”) of specified size, and valve stem diameters to vary not more than one one-thousandth of an inch (.001”), In making Genuine Ford Parts, extreme precision is maintained by the use of Johansson Gages — gages made by Ford Motor Company in the United States and so accurate sistance to tearing, When Answering Advertisements Please Mention July Modern Mechanix All prices subject to change without notice, Genuine Ford Oil Pan Gaskets are made of a treated cork fiber material that has high tensile strength to insure re- tear They pass rigid absorption, compres sibility and weight tests, that they have been ac- cepted as the world's stand- ard of linear measurement. These gages are accurate within two millionths of an inch (.000002”) of specified sizes, And quality is just as out- standing as precision man- ufacturing. Genuine Ford Parts are made of the highest quality materials. 36 kinds of steel are used — each steel of a special type to meet a specific need. When replacement parts are needed, remember that you can get the same precision and quality JOc each, 4 + | = má - A ai. . b p A pm - « g gi my ¢ - _* s í — i -A a i f WPa] má l [sa p I Leri =F." af: -73 i m ayn >) ~ dt: fn hw SI ab tE Pog — qe eee hae or ee ee ne ear a SORE oo E ae Even texture, correct hardness, uniform resistance and long life are features of Genuine Ford Gen» erator Brushes. Per set of three, 18C. that was built into your Ford car or truck at the factory only by using Genuine Ford Parts. Get them from any Ford dealer or from any garage that displays the sign “Genuine Ford Parts.” FORD MOTOR COMPANY Dearborn Michigan Genuine Ford Starter Springs are made of special high-carbon steel. Close tolerances insure alignment bee tween screws, shaft and drive-head. 55c each. 119 Bai fe) $ Seah i ed aeAL_. —-F- sa l=:

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Exposing Counterfeiters [Continued from page 38] stamps of the early Italian and German states. These nations, in case you don’t recall offhand, once were divided into various states—before the turn of the century—and stamps in those days were issued usually by the states and not by the national government. Saxony, as a Ger- man state, for instance, started issuing stamps about 1860 and most of the fine counterfeits of Saxony issues, in the world today, were made between 1860 and 1870. What American stamps have been counterfeited mostly? The 1894 and 1917 two-cent varieties, Mr. Robinette says. Both of these illegal issues were made specifically to defraud the United States government, rather than to bamboozle collectors. Secret Service sleuths located both agencies making these fakes and quickly put them out of business. The bogus 794 two-cent stamp was red in color with a profile of George Washington on its face. Thousands were foisted upon the unsuspecting American people, Mr. Robinette recalls. Careful study of some of these fakes convinces him that they were imitated first by means of a clever photographic process and later engraved. This was likewise the case, he believes with the 1917 two-cent counterfeits. Confederate stamps have been widely imitated, Mr. Robinette says. “The best counterfeit I know about is the little five-cent blue Jefferson, issue of 1862. Genuine copies today catalogue at only 30 cents. The surest way for the average col- lector to identify the fraudulent variety is by comparing the sizes of the real stamp and the suspected one. The fake, in nine cases out of ten, will prove to be a trifle smaller.” Oddly enough, the largest-scale counterfeiting business Mr. Robinette ever heard about was conducted in a semi-legitimate way. In other words, the “big shot” involved admitted, yes, even advertised, that he was making fakes, but said he was doing so because many collectors liked to include a number of good fakes in their collections. He was a Swiss with headquarters in Berne. He had the finest types of stamp- making equipment, including printing presses, perforating machines, color processes and all va- rieties of gum. He was almost a genius in his line and claimed that he could imitate practically every one of the early European stamps. When did he operate? Way back in the period roughly between 1870 and 1880. This amazing individual made other peculiar assertions. He claimed he manufactured “pho- nies” mainly for the sheer fun of it and made very little profit. However, he did a tremendous business and sold to thousands of people all over the world. Always he insisted he never sold a single counterfeit with the deliberate intent to deceive. Maybe not. But scores of shyster dealers obtained some of his finest specimens, directly or indirectly, and cashed in handsomely 120 on them. Today no one seems to know whether or not Swiss authorities ever actually clamped down on his activities. Do you know what a surcharge is? Even the rankest novice collector can tell you. In stamp circles it usually means that the official manu- facturing agency changes the country of issue by means of an “overprint,” which is some fairly simple identifying mark such as the marking of the face of the stamp with a name or a numeral. Another form of surcharge involves, in similar fashion, a change in the regulation postal rate. This might mean, for instance, a 244-cent over= print on a 5-cent stamp. On the other hand, a surcharge might involve a change in the type of postal service. There are, for example, special surcharges used for making special deliveries out of ordinary stamps, or for some particular revenue purpose. There’s a tremendous field in counterfeit sur- charges, according to Mr. Robinette, of the so- called French Colonial “provisionals.” The fakers make a practice of buying, at extremely low rates, a number of the genuine French stamps, which are fairly common, by the way; whereupon they imitate the rare surcharges. For the expert this is easy, since the early surcharges were printed on the face of a stamp in very crude fashion, or else merely stamped on by hand. All the French colonial governments surcharge their stamps by putting the word Obock on a freshly made sticker. The counterfeiters do the same thing, Robinette says, and oftentimes it’s next to impossible to detect the fraud, so expert are the fakers in their illegal art. Many of the early French Colonials have a high catalogue value today, notably the so-called Martinque and Madagascar varieties. For in- stance, the famous “Majungo” issue of Madagas- car—1895 to 1896—list at from $50 to $600 apiece. Their surcharges have been widely and hbeauti- fully imitated. Mr. Robinette has noted many fakes of the famous 1834 issue of the so-called “Bull’s Eye” of Brazil. These are the first general issue stamps known in the Western Hemisphere. They are engraved stamps, are black in color and have enormous letters on their faces, which fact ac- counts for their unusual nickname. “Bull’s Eyes” were made in three values only: 30, 60 and 90 reis. Some of them today rate a high catalogue value. The 90-cent ones list at $150 uncancelled, and $40 cancelled. Most of the other Brazil varieties are considerably cheaper on the collector’s market. ‘Can an expert dealer be fooled? Not very easily, Mr. Robinette claims. He could be most readily taken in, he admits, with an especially fine imitation of the so-called No. 1 Saxony, an early German Colonial. This is a lovely stamp, red in color, bearing the large numeral 3 in a square. ‘There are innumerable fakes of this on the market, printed almost precisely like the original. The best test for determining them [Continued on page 149]

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Pipe ut to oe Casy in q e 4 be or cooarclle OF? Ol CLO, PP oot Copyright 1937 , LIGGETT & Myers Tosacco Co e g

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h RE EEE A | Eg i N ET E An N S EN S E S TOCA © EASTMAN © KEYSTONE © UNIVEX Don’t put off for another day the thrill of owning a fine movie camera! Now you can get all your movie equipment—including film—on easy payment terms, Do business with the largest retailer dealing ex- clusively in home movie equipment. We sell nothing else! Most important of all—we sell either for cash —or on easy payment terms. Terms as low as 10c a day. Mail coupon for free illustrated literature. MODERN CAMERA EXCHANGE, INC., New York City | MAIL COUPON TODAY NOT AN ORDER Send me free literature describing the items checked, together with complete details of your liberal 10c a day plan. [] UniveX 8 mm. [] Keystone 16 mm. [] Eastman 8 mm. Modern Camera Exchange, Inc. 1270—6th Ave., Dept. 10, New York City COO eee ROR O RO REO E EH E EETHEEHEHEH ERE EEO TEETH OHO EERE ETE He wee eee HERE IT IS—SPORTCYCLE, THE LATEST FORM OF SWIFT, ECONOMICAL, THRILL- ING. TRANSPORTATION!—ONLY $59! A light weight, easily handled, comfortable power-scooter. Has air- wheel tires, dural beam frame, A dependable, powerful air-cooled . Goes 30 miles per hour, climbs steep hills, makes 100 miles per galion. Sportcycle takes you where you want to go at a cost 1% cent per mile. To work—to school, for real fun—ride your own sportcycle. As much fun as a motorecycle—dependable as a car—safe aS rail transportation. Cheapest power transportation known. Thousands will ride a sportcycle. Practical and enjoyable for men and women, girls, boys—S to 80. Write now for illustrated folders and complete details. SPORTCYCLE SALES Division of Kay Motor Corp. 580 Market St. San Francisco, Calif. {| Eyes is a golden opportunity for Agents. Many of your friends are prospects for a Sportcycle. 122 Carleton Ellis, Chemist [Continued from page 118] freely in ocean water. Stranger still, it will not leave a ring about the bath tub. Another of Ellis’ discoveries in connection with petroleum reads somewhat like a miracle. It will be recalled that during the War the wings of airplanes of the United States and its Allies were frequently set afire by incendiary bullets, whereas the German plane wings were non- inflammable. This difference was due to the fact that the cloth covering of the German planes was impregnated with cellulose acetate, whereas our planes had to be coated with gun cotton through lack of acetone—the conventional solvent for cellulose acetate. A plea for acetone was sent out from Washington to the chemical profession. Mr. Ellis at the time the plea was received was in the midst of his experiments leading to the separation of isopropyl alcohol from petroleum. Reverting to the formulae of his notes Mr. Ellis saw intermingled therewith the acetone formula. “It literally jumped out at me from the petro- leum formula,” he later related. “It was the first time in my career that an invention came easily.” A test run was made, yielding about ten gallons of pure acetone The War Depart- ment was notified. The chief of the Signal Service, Chemical Warfare, rushed to the Ellis Laboratory at Montclair, to verify the claim. The process was repeated to his amazement, which he accepted with doubt, saying “there must be a “nigger” in the wood pile somewhere.” Nevertheless for the duration of the War all the acetone required by Uncle Sam was produced in a small plant Ellis had previously built at Bayonne, N. J. Carleton Ellis looks the clever inventor and metropolitan business man that he is. Still in his fifties, his step is spry to the point of being youth- ful. The courteous, mild manner of Carleton Ellis belies the unbelievable energy stored within the man. He frankly admits that he gets more pleasure out of chemistry than from golf, yet he is a confirmed golfer. “You see,” he ex- plained somewhat apologetically, “one must have regular exercises to keep physically fit.” Fireworks For Festivals [Continued from page 47] month’s earnings of a coolie. They also charge that the Chinese “flash” crackers are cheaply made, with quick burning fuses, and are unsafe. , Manufacturers state that most accidents are caused by the use of such fireworks. American fireworks, they claim, are more carefully made and possess more-slowly burning fuses. Inci- dentally, American fire crackers seldom measure more than five inches. This is due mainly to the fact that the government demands that manufac- turers make their product safe enough for use by the general public. Accept No Substitutes! Always Insist on the Advertised Brand! ~*~ s E a a 3 » ` s -= > Hu he y J ae i oe po = a ali afica u a gy es - bs em ins ST w > F LATE paa, t ee ar UD- d ed | a ee ee ae e s oe ae ke =: =e 3 oi ek eT ee lg ae EE ia ee i on nee tr ile anne: a

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| The VACU-MATIC Co. Wauwatosa, Wis. -SANES GAS Guaranteed Gas Savings VACU-MATIC proves itself on every car., It is guaranteed to give worthwhile gas savings, quicker pick-up, and’ more power or it costs you nothing. You can instantly tell the difference in added power and motor performance — you quickly notice the cash savings on gasoline, Fits All Cars VACU-MATIC is constructed of six parts, assembled and fused into one unit, correctly adjusted and sealed at fhe jactory. Nothing to regulate. Any motorist can attach Í VACU-MATIC in ten minutes., Once in, its only reminder | is the surge of instant power and speed it gives to the motor and the savings i it affords your pocketbook. i Free Details You owe it to yourself to know all about this remarkable discovery. Mail the coupon below. Start saving gas VACU-MATIC offers a splendid opportunity for unusual sales and prof» its. Valuable terris tories now being assigned. Check and mail coupon. driving thrill! There’s no obligation— so get the facts now! Write today! For a quick, cool breeze through your whiskers, try Treet Blades! Extra stropping gives their edges greater keenness — gives you greater shaving comfort! Get more shaves for your money — get Treet Blades, today! Treet Safety Razor Corp., Newark, N. J. Name en CED oD moast ~ ewer + SET with VACU-MATIC and enjoy anew Í Address © OP SdO0 + its C4 006 G00 + oo SEs 806 © Gs ORES PTT Ore Í City. -seeee eee & eee sy O o RRL States cog qe oem ae ome evens PRINCIPLE AT LAST! Automotive engineers have smashed down che barriers to perfected combustion! The new VACU} MATIC solves the secret of greater power! With almost magical action, this amazing invention instantly puts new life and pep in any motor. It adds mileage to every gallon of gasoline , ,,. produces split-second pick-up, sensitive accelerator response, quicker starting, greater speed and smoothes running. itsrmmoelé= « Nothing Like It! The self-srarter — four wheel brakes = knee action == streame lining ... and now VACU-MATIC! The sensational money» saving invention! With it, engineers have achieved 2 practical means of balancing air and gasoline automatically for all speeds. VACU-MATIC is entirely different? It operates on the supercharge peace by automatically adding a charge of extra oxygen, drawn free rom the outer air, into the heart of the gas mixture. It is entirely AUTOMATIC ‘and allows the motor to “breathe’’ at the correct time opening and closing automatically as required. Wo idling troubles= no carburetor adjustments necessary. It is so simple ic will amaze you —so practical it will save you many dollars on gas costs, | — — — — — FREE OFFER COUPON — — — — 4 THF VACU-MATIC COMPANY 9617-316 W. State St., Wauwatosa, Wis, Gentlemen: Please send me full particulars concerning the VACU» MATIC and details of your Free Offer. This of course does noè obligate me in any way, O Check here if interested in selling proposition, Lat as Sek ei ae es as ee ee oe ee ae i When Answering Advertisements Please Mention July Modern Mechanix 123

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Whole Life Policy / Other ages at proportionately low cost. Postal has no agents; it guarantees low cost. Send coupon to find out what this policy will cost at your age. Postal offers you the life time protection of real Old Line Legal Reserve Life Insurance with cash and DIVIDENDS loan values and all standard provisions guaranteed in the policy. Low initial rates GUARANTEED —reduced still further by TWO DIVI- DENDS—a guaranteed 91⁄2% dividend and an additional contingent dividend as earned. business under the rigid New York State Insurance Laws subject to the United States Postal authorities everywhere. te its policy bblanee wid beneficiaries during 32 successful years. $45,000,000.00 PAID OUT Postal Life does and is Get the facts! Insurance is vital. Find out how much you can save with Postal! Mail this coupon today.) po NNNNNNN ENAN N W 5il Fifth Avenue, Dept. W -293 ostal Life insurance Company m Ce ret ste CMs las ‘eh E New York, Gentlemen: Send me without ea complete informa~ | Wi tion about your low-cost $1,000 WHOLE-LIFE Policy at i my age. a Bj Name CRMC HOHH SSO OTOL HT GOTH SRE D ET HEE OEeo SESE eedeees | Bi Street TE T.. Bi City “ete ee eeevreevpeeeceseeeeeeeaeoeeeaneeanenace SEO e oe aE Et z E Date Of PE enee «-.-Occupation....... soeia aiaa i APRINTINGII Gi offers BIG PROFITS Cards, Stationery Circulars, etc. Easy rules, Sold direct from fac- engraving. Junior press, $5.90. Larger, gli: s power, $147. ‘Do Your Own Printing: Save Money. Pays for itself in short time, Write for full details, THE KELSEY Com- 124 panys Y-9;, MERIDEN, CONN. TOOLS are the Finest that money can buy Send Postcard for Catalog M BONNEY FORGE & TOOL WORKS Allentown, Pa. ` No. 19 Tulype Wrench Set. TuType Wrenches provide a box and open-end wrench in the same tool. Both openings are the same size. The four wrenches have openings from 7/16" to 5/8”. Made of ZENEL Steel, chrome-plated. = a ie 4 ate Oi ere ee wt tory only. Doesraised printinglike R ho Om ey ele Building A Midget Racer [Continued from page 85] 14” thick and 144” diameter is enough. Fasten the brake drums to the rear hubs, inserting an aluminum space ring between the drum and the hub. The drums, which are 8” in diameter, are taken from a Model “T” Ford, 1925 or earlier. Austin brake shoes are used, the “fish-plate” be- ing attached to the spindle body with four 5-16” cap screws. Timken bearings, like those in front, are installed in the rear hubs. Make the rear radius rods in the same manner as the front ones. Instead of flattening the ends, cut off pieces of steel rod of the right diameter to fit snugly inside the tubing, turn them down to 12” diameter for a length of 25s" and thread them at the small end for a distance of 58”, then slip the large end into the tubing and weld into position. Now, bend them so they will go through the spring eyes and anchor-bolt eyes on the spin- dle bodies, holding the latter in place on the ends of the springs. The center of the ball joints should be located midway between the top and bottom of the side rails. Make the cowl frame 12”x20 gauge square tub- ing, electric-welding all joints. The front part consists of two pieces, exactly alike, with a 1-16” thick sheet metal fire wall between them. The bearing for the steering rod is fastened to the cross-member of the rear part. This bearing is a casting made just like the steering gear bracket, except a bit smaller, fitted with a bushing reamed to fit your steering rod. Mount it on the cross- piece with 3-16” bolts. The dise wheels are of very novel construction, being made from “T” Ford emergency brake drums, 1926 or ’27 model, to which are welded air- plane rims, drop-center type, for: 20”x4” tires, braking surfaces having been removed from the drums. The tires are of the non-skid type, and may be purchased through any Goodrich, Goodyear, or Firestone dealer. These tires were not intended for use on an automobile, or course, but they are admirably suited for a racing car of this type, being built to stand up under the severe punish- ment they receive on an airplane. At ordinary speeds, their mileage will compare favorably with. that of regulation automobile tires. Bolt the cowl frame to the side rails by means of right-angle fittings made from 18 gauge sheet steel. The foot rest, made in the same manner as the seat, is bolted on with 3-16” bolts, and should be located to suit the driver. You have, of course, noticed that the steering wheel is located slightly to the left of the center- line of the chassis. But this really makes no dif- ference, since you naturally lean to the left in driving, and, even if you didn’t, the distance off- center is too slight to be noticed. Most profes- sional one-man racers have the steering wheel a little to one side. However, if you insist upon [Continued on page 127] Accept No Substitutes! Always Insist on the Advertised Brand! A. i a Dn K - 4 á z L -— a S .- = hoe, Sl Oe Sata! 1B. oo Ss eM ee Tue "ind 14 Cw Bi Be ws a res

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Eo crel AEF Kadi “a BALL JOINT Pe NB E 1 Auto Trailer Coupler © o e $1.95 WORLD’S SMALLEST REAL PERFORMING Rocky Mt. States West, $2.25, Postpaid only gas. complete. ‘Receives RADIO; Adjustable Bumper Hitch . $1.35 | Bifiene vias” seereewen, Rating fo salut of remy, out d to his hitch can be put on, taken off, DIRECTLY FROM FRONT OF RADIO. Has patented ‘new Speake: Postpaid $1.85 without ball (Rocky Mt. ‘States Progdeast hand. police and sirpiine calls. the newest tadio sensation eee oy Like NEW/ PAYS Te $7225 HOUR. KAR- NU refinishes any color automobile easily, quickly and economically without a Polishing, waxing, rubbing or painting. JUST WIPE IT ON WITH A CLOTH Magic-like fuid covers old paint with tough, elastic coat. Absolutely transparent, crystal clear, self-leveling, self-polishing. Guaranteed, eee 3 to 12 months, Equal in beauty to repaint job costing $25 ta Write for Free Sample to prove our claims and Territory offer. KAR-NU CO. Dept. T-83 Oakley Sta. Cincinnati, 0. > FROGS

HUFOMD GIANTS WEIGH E MARKETS WAITING! UP TO 3 1BS. EACH BZ cee Season Just Starting! Frog FRE e legs in big demand at good prices the year round. Millions used yearly! BOOK We have one of the largest frog markets in the world. Sell to us in addition to ieee other waiting markets. Men & Women starting in every state and Canada! New’s the time to begin. Small pond starts YOU. FREE BOOK explains unusual offer to beginners. Get this year’s eggs. Write today! American Frog Canning Co. Dept. 119-MM New Orleans, La.

When Answering Advertisements Please Mention July Modern Mechanix 125 wil m a Tie a Toe Pan 6 ee aaa 1 aie, a =a oft et ne ĖĚĂĖ a. 0 le ee Bt Pree es VS Mee ee Oe BS ie ee ee

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“5 rue a IS PISNA, > a EE eat S A ea Know as Experts Know It—and Get an Expert’s Pay? Recovery has begun! The months ahead are charged with signifi- cance and expectation. What will you do to get the jump on the other fellow? Thousands of men haye used The Croft Library of Practical Electricity The Croft Library is a complete electrical educator. It is founded on practice—on 20 years of shirt-sleeve experience—on work as it is actu- ally done. It is jammed from cover to cover with the kind of hard- headed facts you want. Written so that the beginner can easily understand it, yet so sound, so thorough, that it is the daily guide of 29,000 highly paid electrical workers and engineers. Croft tells you the things you need to know about motors, generators, armatures, com- mutators, transformers, circuits, switchboards, distribution systems— electrical machinery of every type—wiring for light and power—wiring of finished buildings—underwriters’ and municipal requirements—il- jumination in its every phase—the most improved methods of lighting— lamps and lamp effects, etc.—how to do a complete job, from estimating it, to completion. No money down—easy payments Fill in and mail the coupon attached and we will send you the entire set of seven volumes for ten days’ Free Examination. We take all the risk—you assume no obligation. If you decide to keep the books, send $1.50 in ten days and the balance at the rate of $2.00 a month. Send the coupon NOW and see the books for yourself. |] FREE EXAMINATION COUPON | | McGRAW-HILL BOOK CO., 330 W. 42nd St., New York | vine miners ae Gee Eemnes Ezememi Henar hemo Eam Send me for ten days’ free examination the Croft Library of Practical Electricity. If satisfactory I will send you $1.50 in 10 days and $2.00 monthly until the price of $19.50 is paid. If not | wanted, I will return the books postpaid. (To insure prompt shipment write plainly and fill in all lines.) urapa ooa a O E a a an quay enn eaten a eee | HOME- -AUdrESS gasra naaa a H a = | | City and State _......... e oea raa eara E etiell im diarioa | POSHION! wacn nen new ea deem eS esenee amependa - i of Company- ennea en ae a a rr a E a oe MMx-7-37 WEIGHS Tay EIEE OW, an Evin- rude for only $45 . « . and what an Evinrude! Weighs little more than a pair of oars... drives good sized boats up to 514 miles an hour... uses only asingle quart of fuel in 114 hours! Famed Evinrude Hood- ed Power construction, water-sealed silencing and finger-tip controls. Smooth, quiet, depend- able power for row- boats, fishing craft, canoes, dinghies. Write today for complete cat- alog on the Scout and other Evinrude models. Address, EVINRUDE MOTORS, 5209 N. 27th Street, Milwaukee, Wis. EVINRUDE SCOUT F..0. B. FACTORY SUBVECT TO CHANGE WITHOUT WOTICE WRITE FOR __ CATALOG cor A Midget Superheterodyne [Continued from page 103] through a “banana”? plug and jack combination to facilitate connection and disconnection. This jack is located at the rear of the subpanel, on the extreme right. From the jack, the impulses feed into the primary of a standard tuned-radio-frequency antenna coil of the proper inductance for broadcast band coverage, or short wave, according to which range is desired. This antenna coil should be equipped with a coupling ring. The lower end of the primary winding is grounded to the chassis and also connects to the rotor plates on hoth sections of the 2-gang t. r. f. variable tuning condenser of .000365 mfd. capacity. The local frequency for mixing is generated in a padder system oscillator, using a pentagrid oscillator coil for ex- citation. The padder condensers have a total capacity of 1200mmfd., combining an .0008-mfd. fixed mica condenser shunted across a 400-mmfd. variable padding condenser. The value of the oscillator resistor is 50,000 ohms and the grid condenser has a capacity of .00025 mfd. The B supply for anode grid No. 2 is fed through a 15,000-ohm voltage reducing resistor, from the positive 135-volt source. Notice that all voltage taps are connected to the 5-prong socket at the back of the sub-panel, allowing the batteries to be plugged in. At the juncture of the plate winding on the oscillator coil and the 15,000-ohm voltage dropping resistor, a by-pass to ground is provided through a .05-mfd. fixed paper condenser. Note that the recommended grid bias is applied to the control grid of the tuned signal section of the 1C6 tube from the negative three-volt tap on the C battery, this being dis- sipated through a .25-megohm resistor. There are some cases in which the set may work better without this grid bias, but that is the exception, rather than the rule. A .05-mfd. fixed paper condenser is used between the lower end of the antenna coil secondary and the ground to pro- vide a signal path without allowing the C battery to become shorted. The screen grid of the 1C6 tube is supplied with a positive potential off the sliding arm of the regeneration potentiometer that also feeds the screen of the 32 detector. The I. F. transformer is of the compact midget type and is peaked at 175 kilocycles for broadcast use. Since this coil is not provided with a tickler winding, one must be added to facilitate feedback from the plate of the 32 for regeneration. By loosening the two small bolts at the top, the transformer can readily be slipped out of its shield can. The tickler is wound on the outer end of the core, about an eighth of an inch from the secondary winding as shown on drawing. The tickler should consist of about 10 feet of No. 36 d.s.c. magnet wire, wrapped in the same direction as the secondary of the transformer. This is im- portant! After winding the tickler, dip it several times into melted paraffin, allowing it to cool and harden between dips. ‘This will hold the winding in place. The gridleak is a 2-megohm resistor; the grid condenser has a capacity of .00025 mfd. Regeneration is controlled by means of a 50,000-ohm potentiometer. The positive lug of this potentiometer con- nects to the positive 135 volts B through a 30,000-ohm fixed resistor. The negative end makes contact with the negative B supply at the chassis. The moving arm, on center tap, connects to the screen-grid taps on both the socket for the .1C6 and the 32 tubes. From the center lug, a .5-nfd. fixed paper condenser by-passes to the grounded chassis. In connecting the tickler winding it is best to experiment by hooking it first one way and then, if the set fails to work satisfactorily, reversing the leads after making sure, however, that the fault does not lie elsewhere. The 40-millihenry radio-frequency choke is of the mounted type, bolted to the under side of the chassis. From the end of the choke connected to the tickler coil, a .0001-mfd. fixed mica condenser is used to provide a radio-frequency by pass to the ground at the chassis. The filtered signal flows from the radio choke to the 750-henry audio-frequency choke. The latter choke should be of the type that is especially recommended for use with screen-grid detectors. ‘The lower end of this choke con- nects to the positive 135 volt B at the battery plug-in socket. A 250.000-ohm resistor is shunted across the audio choke to thwart threshold howl, that annoying squeal that is the ban of regenerative sets, and to provide a voltage path to the plate of the 32. A .01-mfd. fixed paper capacitor is used as a signal by-pass voltage blocking condenser to the control grid of the 33 tube. The grid resistor for the 33 tube has a resistance of 500,000 ohms and the lower end connects to the negative 13.5-volt tap on the battery con- nector socket. The screen grid carries a positive potential of 135 volts, in accordance with the manufacturer’s recom- mendations. [Continued on page 151] Accept No Substitutes! Always Insist on the Advertised Brand!

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Building A Midget Racer [Continued from page 124] — having it in the center, lengthen the pitman-arm shaft and devise another method of mounting the steering gear housing to the frame. For the clutch and brake levers, use motorcycle gear-shift levers, mounted independently on a short shaft located on the right-hand side rail. The outside lever operates the brakes and should be bent out a little so it will be clear of the clutch lever. Model “T” Ford emergency brake parts are employed for the brake pull-rods; the con- necting rod from the lever to the brake cross-rod and the crank levers on the end of the latter. The accelerator pedal is mounted on the cross- rod and should be slipped on before the crank levers are attached. This also applies to the cross- bearings. Make the instrument board from 14-gauge sheet aluminum and screw it to the cowl frame. In- struments should consist of an oil pressure gauge, a Fahrenheit gauge, a tachometer, and an air pressure gauge. The latter is necessary only when you use a pressure-feed fuel system, which is preferable for racing purposes. The tachometer is connected to the camshaft of the motor by means of a suitable adapter. For racing, a 4-gallon gasoline tank is mounted in the tail of the car, the air-pump being located on the right-hand side rail within easy reach of the driver. A reserve oil tank of 5 quarts capacity is installed in the cowl, making a total oil capacity of around 2 gallons. If the builder does not intend to do any racing, he needn’t put the gas tank in the tail, unless de- sired. There is no need for the oil tank in the cowl since the crankcase will hold enough, so put the gas tank there and use the gravity feed sys- tem. Sufficient room-is available for a 4-gallon tank, which, by the way, can be made by any tin smith. Before installing the motor give it a complete overhauling. Be sure the magneto is in good con- dition and well-cleaned. It should not cut out while running at high speed, especially on a turn as this might result in a dangerous skid. Use racing spark plugs; the commercial type will foul at high speeds. See that the oiling system is working at its highest possible efficiency. In general, put the motor in such a condition that it will turn up a maximum number of revolu- tions. For racing purposes, use an anti-knock fuel instead of straight gasoline. If an Austin transmission is used, the only change necessary in the transmission itself is to remove the bend in the shift lever and shorten it to 8” above the cover. A 44” rod, carried on two bearings of steel tubing which allow it to slide back and forth as well as turn, is mounted just above and along the center-line of the motor and extends horizontally from a point just above the shift lever on the transmission to about 3” in front of the instrument board. The front bearing [Continued on page 129] J à VO a E A ee O e a A new sponge made (like rayon) of Cellulose. Soft, durable, sanitary, absorbent. Get this ` AMAZING SPONGE | | th every | rane No. f POLISH | E make this generous of- fer so that new thousands of car owners will try No. 7 Duco Polish immediately, and see how greatly it improves the ap- pearance of the =e a car. You should use ~ cece No. 7 Polish on new cars as well as old. It keeps new cats beautiful and restores the color and lustre of old finishes dulled by grime and Traffic Film. Now we offer a Du Pont Cellulose Sponge (25c size) FREE to everyone who buys a pint can of No. 7 Polish. (Offer good in U. S. only.) This sponge, created by du Pont chemists, is ideal for bath and household cleaning, as well as for the car. See your dealer WHILE THEY LAST! MSS ES IOS When Answering Advertisements Please Mention July Modern Mechanix 127

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E @. Explains latest in- ventions, methods in photographyand Home Movie Mak- ing, for fun and profits. Offers hun- dreds of amazing, money-saving Bar- gains in stilland movie Cameras, Lenses, Films, etc. All om guaranteed. We take ' yourold Cameraand equipment in trade! Satis- faction guaran- . teed! WRITE! Write for Free Bargain Book? CENTRAL Camera Go. (Est. 1899) 230 S. Wabash, Dep. B-235, Chicago de T =” ie > ——— ` - moes rs Dres CoE = S73 mee - = aa r Auto Engine For Marine Use [Continued from page 107] nipple is welded into each end at the proper angles to clear the manifolds and carburetor. The water is pumped from the lake by a regular marine type pump, mounted on the front timing gear cover as low as possible for self priming and driven by a V-belt which also drives the generator, The cold water is taken directly from the pump through the oil cooler at the rear, to the water cooled exhaust manifold which preheats it slightly before it enters the cylinders. The manifold is nothing more than a discarded Ottwell Heater, which can be picked up at the junk yards, with plates welded over each end and %-inch water pipe nipples welded into the center of the plates. Connections are made between the nipples with rubber hose. The water leaves the front end of the manifold and enters the cylinder head through a nipple welded to a plate which covers the original water pump opening and out through the regular port on the left side of the block. A hole is drilled through the head at the extreme rear and threaded to take a %4-inch pipe nipple which is connected into the exhaust pipe below the manifold. Che extra outlet takes the hottest water from the cylinders and also keeps the hot exhaust pipe from burning the side out of the boat, This completes the oiling and cooling of the motor. The reverse gear is next and made up as follows. Get 2 complete model “T” Ford Transmission and flywheel in good shape at any car wrecking lot. Disassemble and re- move all magnets and the ring gear. Machine the flywheel down to within ™%-inch of the triple gear pins and face off the forward side of the wheel that attaches to the crankshaft. Weld the low speed and brake drums together to form one unit. Machine out a %-inch deep recess in the regular model “A” flywheel to fit the reduced model “T” wheel. ‘The dowell pins and bolt holes in both flywheels exactly fit the crankshaft flange. Longer cap screws are used to hold the wheels to the shaft. Three %-cap screws are then installed between the triple gear pins to further hold the wheels together. Assemble the transmission in the usual way, leaving out the brake drum drive gear. Before installing the driving plate, machine the end behind the clutch spring and around the square universal joint hole to fit the inside diameter of a model “A” rear transmission ball bearing which is pressed into place. A felt washer and spacer installed between the bearing and spring cup will stop any oil leakage. The standard reverse band, only, is used on the reverse drum. With the brake drum welded together, tightening the band on the reverse gear gives you approximately 90% of your forward speed in reverse. This is sufficient for all braking purposes and gives plenty of power for backing out of docks. This completes the reverse gear assembly but as this unit requires oil a case has to be built around it which must be oil tight. It is impossible to balance this unit exact, as the revolving drums will throw it out slightly, but you will never experi- ence the slightest trouble with vibration, since with the unit construction there is no misalignment, The case and controls are next and possibly the hardest part to build up. Install the standard Model “A” flywheel housing after welding up the small hole in the bottom and place a gasket under the starting motor and the small plate which covers the rear main bearing cap. These must be oil tight. Next take an old Model “A” clutch housing. Cut it off, 314-inches to the rear of the face which bolts the flywheel housing and with this ring bolted to the housing and the transmission assembled, a U-shaped piece of boiler plate -inch thick is shaped to fit over the assembly. The rear end will have to come over the bearing on the driving plate and a cardboard template cut out and fitted first. Any tin- smith will cut out and shape the boiler plate for very little. An inspection hole of sufficient size through which to reline the band, when necessary, is left on top. A model “A” Universal inner ball cap is used at the outer end. This can be machined out to fit the outer diameter of the ball bearing and a flange welded to the cap to further support the bearing. After all parts are cut and fitted, weld the entire unit to the clutch housing flange. Have everything ready und do all welding at once. Preheat the entire housing, using cast iron rod and flux and no trouble with cracking will be experienced. Bolt the case to the motor and align and bore the holes in the case for the band tightening cam and the clutch ‘“‘throw- out” shaft. ‘These can be cut out of an old model “T”? trans- mission cover and welded into the new case.

They will fit with very little altering. The inspection plate is next screwed to the top with a gasket under the plate. The outside adjusting screw for the band cam can be welded in when taken out of the old case. A little head work is necessary in fitting up the controls and band tightening cam. Remember as you tighten the band, the clutch plates must be released. One-half inch water [Continued on page 134] Accept No Substitutes! Always Insist on the Advertised Brand! ‘2 oo ee Sar P m [ = a ‘

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Building A Midget Racer [Continued from page 127] for this rod is mounted on the front end of the motor, and the rear one on the fire wall. A handle about 6” long is attached to the rear end of the rod, extending downward so it can be reached below the instrument board. A rubber grip may be slipped on it if wanted. On the front end of the rod, weld a piece of 94” tubing, extend- ing down over the shift lever knob with an over- lap of about 1”. The transmission will be in- stalled backward in the car. Gears are shifted in the following manner: Reverse—Twist handle to your right and pull to- ward you. Low—Twist handle to right and push. Intermediate—twist to left and pull. High—Twist to left and push. Hook up the clutch lever, using a “Tr”? Ford emergency brake pull-rod, cut to length. This arrangement is clearly shown in the photograph. Shifting the gears may be a bit awkward at first because you have to operate the clutch by hand, but you'll soon become accustomed to it. How- ever, it would be an easy matter to rig up a foot pedal if desired. For the throttle control, a vertical rod con- nects the pedal to an “L’”-shaped lever, mounted on the fire wall directly over the pedal and level with the throttle lever on the carburetor. The “T”? lever is connected to the carburetor by a flexible tube and piano wire—just as the throttle control on a motorcycle. Locate the spark control on the instrument board, using an airplane-type “T”-handle dash control, obtainable from most air-craft supply companies. With construction advanced to this point, the builder now has the entire chassis of his “Arlen Special” completed except for the installation of the 4-cylinder motorcycle engine. In next month’s concluding installment we will take up the con- struction of the racing body and the other de- tails which will give the midget racer the neces- sary finishing touches that make for a truly beau- tiful and highly satisfactory dirt track speedster. Fish Made To “Clean House” An ingenious way of making young trout clean house, that is to say, sweep out the debris in their pond, has been devised in a new type of trout rearing pond. By putting the fish to work, the Bureau of Fisheries in Washington expects to save consid- erable time of attendants who have had to scrub the ponds with brooms. The new house cleaning system is to draw off the water in the pond to a low point, introduce a stream of water low in the pond, and then the fish mop up by scurrying over the bottom, carrying the debris with them and dumping it in a catch basin. Ge’; l F, PA U im MW 200.40 MUSSELMAN COASTER BRAKE It will be easy for you to write a slogan about the greatest coaster brake the world has ever known. Write in 10 words or less, a slogan that can be used for advertising this marvelous brake that makes all older coaster brakes obsolete and behind the times. Here’s a sample slogan: “The coaster brake that’s years ahead.” See your dealer and examine this different, spectacular coaster brake. Study the features and you'll be so en- thusiastic youll write a good slogan. With this cartridge unit, the Musselman 1937 Coaster Brake can be reconditioned as easily as changing a safety razor blade. Don’t buy an obsolete coaster brake — demand Musselman. You can get it on any bicycle without extra charge. Then you'll have quick braking; easier pedaling and win every coasting contest. Slogam contest prizes are: Ist, $100.00; 2nd, $35.00; 3rd, $15.00, and 25 prizes of $2.00 each. See your department store, hardware or bicycle dealer now and send your slogan today. Contest closes July 15th. Awards made July 25th. Demand the new Cartridge Brake on your next bicycle. COSTS NO MORE THAN THE ORDINARY COASTER BRAKE VK . aN LIN CONTEST aides TO DAY AAN Write for free literature THE MUSSELMAN HUB BRAKE CO. 6224 St. Clair Avenue Cleveland, Ohio eee When Answering Advertisements Please Mention July Modern Mechanix 129

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ie 7 FOOTE ae Ce f inside Trade information for Carpenters, Builders, Join- ers, Building Mechanics and all Woodworkers, These Guides give you the short-cut instructions that you want— including new methods, ideas, solutions, plans, systems and «4 vols.56 gh FE x E OAEI money saving suggestions. An | PAWIA easy progressive course for the O N E AORE SE Ar pren oe ana Sneen: = Th AEII iN ai Valeo 6 practica aily elper an Been aan Worn phe Sree ley AM Quick Reference for the master Ree eT ee aL Gal era WY Ang worker. SPE 5 “Ph where are using these Guides uta rane ee as a Helping Hand to Easier aca AIE E NRS Work, Better Work and Bet- KA et) Bi ter Pay. To get this assist- aE EE = ance for yourself, simply fill in and mail the FREE COU- Carpenters every- ay E Inside Trade Information On: PON below. How to use the steel square—How to file and set saws—How to build furniture—How to use a mitre box—How to use the chalk line—How to use rules and scales—How to make joints—Carpenters arithmetic—Solving mensuration problems—Es- tamating strength of timbers—How to set girders and sills—How to frame houses and roofs—How to estimate costs—How to build houses, barns, gar- ages, bungalows, ete.—How to read and draw plans—Drawing up specifications—How to ex- cavate—How to use settings 12, 13 and 17 on the steel square—How to build hoists and scaffolds— skylights—How to build stairs—How to put on interior trim—How to hang doors—How to lath— lay floors—How to paint THEO. AUDEL & CO., 49 W. 23rd St., New York City Mail Audels Carpenters and Builders Guides, 4 vols., on 7 days’ free trial. If O.K- J will remit $1 in 7 days, and $l monthly until $6 is puid. Otherwi.e I will return them- No obligation unless I am satisfied. AERONAUTICAL UNIVERSITY ENGINEERING, LICENSED MECHANICS ADMINISTRATION e RADIO SHEET METAL o WELDING B. S. Degree. Graduates with all leading aviation companies and air lines. Day and eve. classes. State Accredited. Government approved. Write aana for “Aviation as a Career.” Aeronautical Uni- w versity, Curtiss Wright Bldg., Dept. M, 1340 S. Aseli Michigan Ave., CHICAGO, ILL. NEED MONEY? Write for free booklet describing *107 Plans for 1 Operating a Successful Business of Your Own”. he Make from $20 to $100 a week starting in spare | time at home. No peddling or house-to-house selling. Booklet sent free, and without obligation. Write for your copy today. , ELITE PUBLISHING CO. REE 214 Grand St. New York, N. Y. BOOK Dept. G WHY RENT A BOAT? MAKE YOUR OWN Even a child can build at least one of the many boats that are described in the big new 148-page book, HOW TO BUILD 20 BOATS. Send 50c for your copy, now. MODERN MECHANIX PUBL. CO., Fawcett Bldg., Greenwich, Conn. INVESTIGATE WORK FOR U.S. GOVERNMENT! Thousands of openings yearly. Men—Women, Start $105-$175 month. Get ready age 18-50. Details Free. now for next entrance test. W rite INSTRUCTION SERVICE, Dept, 233, St. Louis, Mo. 130 Le oe _o ia ae. mm ae a Tapped Metal Accessories [Continued from page 105] through the button switch and then carry them both on up through the brass bushing, attach to the socket and then slip the shell over the candle socket. Finish all of the iron work with one coat of flat black paint. Allow it to dry thoroughly, then with a piece of emery paper wear off enough of the paint so that all of the highlights show up well on the iron. Dissolve a small piece of liver of sulphur in about a quart of water, wash over the outside of the shade until the copper takes on a dark brown color, wash and let dry thoroughly. Buff or polish the shade and coat with lacquer to preserve the finish. The shade is attached to the bracket with a round head brass screw which passes up through the apex of the shade, through the bracket and into a brass terminal which may be obtained at any electrical supply store. Like the lamp, the owl book ends are simple to make and the material required costs little or [Continued on page 153] Backyard Railroad [Continued from page 32] Quinby made movies of the doomed railroad. From the film, he made enlargements of rolling stock, bridges, stations and other features, fol- lowed by scale drawings. Bit by bit, over a period of years, he has built the miniature replicas of the multiple-unit electric cars, elec- tric locomotive, work car, freight cars, tunnels, bridges, trestles, power house and other features. For several years the road has been in constant operation, summer and winter alike. As secretary of the Electric Railroaders As- sociation, a nation-wide group of enthusiasts who make a hobby of real and make-believe electric railroads, E. J. Quinby has set the example with his back yard road. In fact, his railroad is the official test track for models built by other mem- bers. Many a Saturday, the fond builders of tiny locomotives and cars try out their handi- craft on the 250 feet, or one full scale mile, of track. This distance gives the models a chance to display their speed. For utmost realism, the trains and cars are controlled from either the fixed controller—the real thing, actually taken from a dismantled electric car—or from a porta- ble controller set anywhere along the line. Current for the trains is provided by a minia- ture concrete power house containing a rotary converter and switchboard with meters, circuit- breakers, indicator lights and switches. The usual 110 volts A.C. is converted into 25 volts D.C. If a short-circuit or excessive drain occurs on the trolley line, the circuit-breaker automatically kicks out, protecting the rotary converter. Accept No Substitutes! Always Insist on the Advertised Brand!

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Heart Operation Performed [Continued from page 40] insect on a hollowed-out block of paraffin. Next he took a fine piece of human hair and .tied the wee heart to a finely balanced glass needle. A spot on its very end was darkened so that a bright light thrown across the darkened tip would cast a moving shadow as the needle moves under the heart impulses. Immediately, the lens of a high-powered micro- scope catches this shadow, magnifies it many times and throws it into a special camera where it plays over a slowly moving sheet of photographic paper. This makes a permanent record of the “fingerprints” of the insects heartbeats. These highly magnified “fingerprints” are able to trace on lines resembling seismograph (earth- quake) records, the normal rhythm and contrac= tion of the bug’s heart. Ordinarily these lines are even, but they become jagged and irregular as the heart is drugged with nicotine. Finally, while the wee organ slowly wore off the effect of the poison, the photographic records revealed the slow return to normalcy in lines that became more and more even. The unique tests offered weird results. Occa- sionally the heart, apparently normal, showed the queer habit of “reversing itself” for no reason known to science. In summing up his experi- ments Dr. Yeager says: “We plan to try out numerous drugs in order to get at the basic facts of insect heart action. Discovering the funda- mental things that make insects tick eventually will help other scientists find out what makes them stop ticking, so that when they become too ruinous to the nation’s crops they may be de- stroyed effectively.” The Subway City Grows [Continued from page 54] connecting New York and New Jersey, which accommodates about 11,000,000 auto passengers every year, there has been a movement to build fewer bridges in congested areas. The War Department sympathizes with this movement because fewer bridges will simplify harbor pro- tection. The newest tunnel under the Hudson is called the Midtown, 8,000 feet long and 31 feet in diameter on the outside, and 21% feet wide on the roadway. This same tunnel may later be driven clear across the island of Manhattan and beneath the East River, emerging finally on Long Island. Underwater tunnel construction is usually more expensive than ordinary subway work. The new Midtown costs about $40,000,000 for a length of one and one-half miles. The heroes of construction on the vehicular tunnels are the muckers, sand hogs and engi- neers who work under conditions that make many so-called hazardous jobs appear very tame. is ws . = School Co Many Finish in 2 Years You can complete thissimplified High School Course as rapidly as your time and abilities permit. Equivalent to_resident school work —prepares you for entrance to college. Stand- ard H. S. texts supplied—Diploma. Credit for H. S. subjects already completed. Single sub- jectsifdesired. High Schooleducation is very important for advancement in business and industry and socially. College Entrance During the past 14 years, our High School graduates have been admitted to 531 different Universities, Colleges, Junior Colleges and Normal Schools—80% of them without entrance examination. Course also prepares for teachers’ certificate and pre-professional examinations. Business—Industry To get and hold a good position in Business today you must be able to write clear, accurate letters and re- ports—do figuring involving Algebra and Geometry— talk intelligently on matters requiring a knowledge of Geography, History, and Economics. In Industry—Mechanical and Engineering lines— you must have at least an elementary knowledge of Physics and Chemistry—be able to figure quickly and accurately—know something of Mechanical Drawing and blueprints—and be able to talk and write ac- curately and clearly on both your work and ordinary topics of conversation. Our High School course meets the preparatory edu- cational requirements for Business and Industry. An Educational Institution The American School was chartered in 1897 as an educational institution, not for profit—and is exempt from paying Federal income tax, like the best resident colleges and universities. Don’t Be Handicapped— Complete Your Training Now Be a High School Graduate! Prepare yourself for promo- tion in Businessand Indus- 2 0 Oth C C the S ToteanjonS, ollege Entrance and so- er Sourses cial success. No matter Over 150 noted Educators, En- gineers, and Business Men helped prepare our special in- struction material, which is used by many resident schools and colleges, U. S. Navy, and Province of Manitoba, Canada. e offer you quality training at home for the best- paying what line you may select, High School training will prove invaluable to you! Our moderate fees cover all instruction, standard textbooks and Diploma, Easy monthly terms. Get lines of Industry and Business, as listed in the coupon, ahead in life. Start your training NOW! Mail coupon for information about line that interests you American School, Drexel at 58th, Chicago a ee ee eee ee ee ee ee ee eee — e e ee ee eee ee ee ee eee American School, Dept. HB28, Drexel at 8th, Chicago Tell me how to train for success in line checked. No obligation. O High School Course OH Accounting &Auditing ODiesel Engineering OlArchitecture & B’lding O Drafting & Design OoAutomotive Engin’ring. ODO Liberal Arts O Business Management [O Private Secretary OCom’'ercialAeronautics OHi’erAc’t’¢(C.P.A.) O Electrical Engineering OHighway Engin’r’'g O Electrical Refrigerata OMechanical Eng’r’s O Air Conditioning O Radio & Television O Civil Engineering O Salesmanship O Complete Law O Steam Engineering KES a a E cna a aa a soe When Answering Advertisements Please Mention July Modern Mechanix 131

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= MECHANICS & WELDERS GOOD JOBS and Mighty GOOD PAY Do you want to earn big money? If so let us know which of the following trades you prefer. You learn by doing. Practical work. Expert teachers. Low tuition. Personal attention. It will pay you to investigate AT ONCE. Just check the courses you’d like to take and mail today. You will receive full information, absolutely without cost or obligation. But don’t delay. Check the Trade You’d Like to Learn O Welding O Spray Painting [|] Torch Soldering [|] Auto Mechanies [|] Auto Collision O Metal Finishing Name eoeecoeoWwerveeeegeeeoeseveespeeoneeogoeeeseeeceoeoeeeeaeeeeeaese Address Ask about our Pay-After-Graduation Plan Mail the above to MICHIGAN Ba TRADE SCHOOL Wa 3763 Woodward Avenue DETROIT, MICH. “2 © oer *®eoevereaene oeeoeeaooeeeveeote@eeo* **pneeeeeess Splendid opportunities. Prepare quickly in spare time. Easy method. No previous experience necessary, common school education sufficient. Many earn while learning. Send for free booklet ‘‘Opportunities in Modern Photography’’, particulars and requirements. ERICAN SCHOOL OF PHOTOGRAPAY 3601 Michigan Avenue Dept. 205-B Chicago, Ellinois TRIAL LESSON in Get ready now for new money-making opportunities in Drafting. Clean, well-paid work. Send post card for FREE TRIAL LESSON in Drafting, Shows how easy to learn at home by C.T.C. method. We furnish all tools. Write today. CHICAGO TECHNICAL COLLEGE H 262 Tech Bldg., 118 E. 26th St., Chicago, HI. UPTO $75 WEEKLY YW asta \ RADIO SERVICE . Foe Let R. T. A. Train You At Home Write quick for this Free Book that tells TE you why R. T. A.’s Practical Home Training Course offers the utmost in RADIO TRAINING including Television, Talking Pictures and Public Address Systems. Packed with star- tling facts and interesting illustrations, including our sensational Service Equipment Offer that helps you earn money almost at once. Radio progress is astounding the world. Heed the call of RADIO RADIO TRAINING ASS’N. OF AMERICA Dept. MM-77, 4525S Ravenswood Ave., Chicago, Ill. Photographing Wild Animals [Continued from page 112] wild life. It is a small box containing two flash- light batteries with a socket mounted on top of the box for taking the photoflash bulb. There are two terminals on the outside of the box with wires leading from these to a baited switch which the animal unknowingly throws, thus setting off the flash. The box is made of plywood. The sides are 1% inches high. Two of them are 334 inches long, and two are 2 11-16 inches long. The bottom and top boards extend about a quarter of an inch from the sides. A regular porcelain socket can be used although the inner part of an old lamp socket will do. The two wires leading from the socket go to two thumb tacks which are pressed into the slid- ing board and kept in contact with the batteries. The center terminals of the batteries should be facing opposite directions. A spring attached to the back of the sliding board insures a good con- tact. Although reflectors can be bought at camera stores, a much cheaper one can be made by at- taching the bulb clamp from an old lampshade to half of a tobacco or coffee can. If you do not have an old lampshade from which to take the clamp, a suitable one can be had at any ten cent store. As for switches to set off the photoflash bulb; there are unlimited possibilities. You can use your ingenuity in making one as any little device will do. In arranging the set up, tie the bait to a string, and fix the switch at the other end of the string so that a tug on the string will work it. Another way is to have the switch buried under loose bark or leaves with the bait protruding above ground. The animal will make the contact when it lifts the bait. The wires from the switch to the box can be covered if desired, but this is not necessary. Above all, avoid using a switch which makes a noise or a sudden movement, as this would startle the animal before the flash has gone off. The simple knife switch arrangement shown in the main illustration is recommended. Before attempting to take any pictures set out some bait near the animal’s hole or den or where they will be sure to find it. Do this for severa, nights so they will begin to expect it. Then, when they come for it every night, you are ready to take pictures. After dark set your camera on a tripod or other rigid support, focus it on the baited string and set the shutter for time ex- posure. The battery box can be placed anywhere so long as the flash does not shine into the lens when it goes off. Fix switch and battery box in position and test, holding flashlight bulb in socket, to see that everything is working all right, then screw photoflash bulb in socket and open shut- ter. It is advisable to cover the camera with something to protect it in case of dew or rain. The shutter must be closed again before the [Continued on page 153] 132 Accept No Substitutes! Always Insist on the Advertised Brand!

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Fire Walking—FactOrFable? [Continued from page 60] estimated that the temperature near the surface of the stones must have been at least 400 degrees F. It was noon time, and the fierce heat of the sun was also beating down upon the intrepid fire-walkers. Seven or eight natives then approached, and walked in single file round the oven and out at the point of entrance. They were walking through the fire steadily for a period of at least half-a-minute. The pith and roots of a cabbage tree (which the Fijians call masawe and the Maoris call Ti) were then cooked in the oven and subsequently eaten at the feast. Immediately upon the conclusion of the cere- mony, Dr. Hochen and the others present care- fully examined the fire-walkers. They found the skin on the soles of their feet soft and flexible, and not leathery and insensitive to the touch. The skin of the legs and feet was found to be quite unprepared and uncoated with any chemi- cal substance, as they verified by touch, smell and taste. For the latter tests the tongue was applied to the soles of the feet. The pulse in every case was found to be normal. The feet had also been examined just before the cere- mony began. Examination of the stones showed that they were basaltic in character, and became white-hot in the oven. The brilliance of the noon-day sun rendered their white-heat invisible, however. According to Dr. Hochen, there did not appear to be any trance, or other abnormal condition, on the part of the participants—other than intense faith. The natives cannot explain it themselves, except that it is a “power” which they can some- times transfer to others by holding them by the hand. Few natives in Fiji can perform the fire walk. No incantations or religious ceremonies are per- formed, these having fallen into disuse since the introduction of Christianity. Only the members of a certain clan can successfully perform the walk. Dr. Hochen concludes: that no alum or other substance was employed by the natives; that their feet were not leathery or abnormally tough; and that even if hypnosis or an anaesthetic had been employed to produce insensibility to pain, these would not prevent cautery. He concludes that the whole subject requires a “thorough scientific examination.” | Prof. S. P. Langley, of the Smithsonian Insti- stART E T DRAWING l ARCOLA TO DRAW AT HOME BE an artist and be your ‘‘own boss.”’ You can learn AT HOME in your spare time this simple, practical way. There’s a big future in this fascinating and profitable field for men and women of all ages. few pleasant hours a week should 2 give you the ability to earn good money. COMMERCIAL ART CARTOONING AND DESIGN ALL IN ONE PRACTICAL ee Se Our proven method of instruction includes every branch of Commercial Art, and your drawings are given the correction ` and criticism of an exper ienced Art Instructor, You start by drawing straight lines and in advancing from lesson to lesson you receive all the constructive help you need. IT’S AS EASY AS One - TwWe «TUACE! $40 EXTRA PER MONTH in spare time, writes eudem of Okia hons. PAID FOR COURSE W.R. Kent, New Jersey earned more than twice the price while studying. $25 FOR ONE DRAWING One small pic- ture brings cas to Miss Goldie Hill of Kansas. From a simple framework to the finished figure. Art made easy by simple steps that the average person can follow. The above § is one of the 16 key poses in our IFE = CLASS BOOK, Two Big Artists’ Outfits Given 7 AT NO EXTRA COST! |\iz Includes everything you need started in Art. Mail coupon today COMPOS de= tution, is another who witnessed the fire walk, | 5 WASHINGTON SCHOOL OF ART i this time in Tahiti. His account is much the same. |8 Oe eee og Similar accounts have been rendered by many ` Without obligation, please send me a FREE copy of your S others, and their testimony is markedly similar. | m B0% “Art for Pleasure and Profit. i The latest instance to be carefully investigated : NGG accexon celcaee ces covet ecocveneseecoees AZleccccccces B ` i —that of Kuda Bux—was under the auspices of : Address SEHSHSHSSHSSHSSHHSHHSHSHTHHOHRHOHSHHSOHHHRSSOHOSHOHHHOOHAEHEHTTL% oe Ñ Mr. Harry Price, the Director of the Psychical a City. eee ee Ro ealestas > Will al). State..ccceseves i i ; f J o salesman will ca Laboratory ol London University. A number ðf | i. oe eenaenekn naw nee eeneanm nm” [Continued on page 135] When Answering Advertisements Please Mention July Modern Mechanix 133

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oe an BIG REPEATS and Steady WEEKLY CASH INCOME Sells Fast On Every Counter SURE, the marvelous new breath purifier that instantly and effectively eliminates offensive breath odors such as onion, garlic, liquor and tobaeco, is selling like hot cakes wherever the attractive six-colored, self-serviced counter display is placed. This new product is taking the country by storm, offering salesmen and distributors everywhere the greatest money maker of all time. MILLIONS WANT IT Now you can have a steady weekly cash income and big repeats in a good paying business all your own. Tremendous sales possibilities. Every drug store, restaurant, beauty parlor, tavern, department store, hotel, club, barber shop and many others are immediate prospects for fast sales. SURE is a phenomenal success in Chicago. Marshall Field & Company, Walgreen Drugs, United Cigar Stores and thousands of others are steady repeaters. BIG OPPORTUNITY—ACT QUICK SURE is an exclusive product that offers unlimited sales possibilities to build a permanent steady increasing business. Sell both retailers and wholesalers with practically no capital investment. Get in on the prouna ac of this amazing new seller. Be first to get the cream of 1e profits. SURE LABORATORIES, Dent. 23, 841 N. Wabash Ave., Chicago, III. Se ree EEE SEs, Ug EE: Ma, WER ASE AOs UNCAYO; Pals MONEY BAC GUARANTEE SURE is sold on an absolute money back guarantee. Thousands of sat- isfied customers are now using SURE. APPRENTICES Ambitious, air-minded young men, interested in entering the well paid field of Aviation, write immediately, enclosing stamp, ta MECHANIX UNIVERSAL AVIATION SERVICE, Inc. Strathmore Station Dept. A Detroit, Mich. BECOME A SUCCESSFUL FINGER PRINT EXPERT Prepare yourself for a splendid, steady income. Finger Print Experts are becoming’ a necessity in the Industrial World as well as in the Criminal Field. Here is an opportunity for a Thrilling Career open to Men and Women, Write for Free Finger Print Pub- lication and Particulars. Not sent to those under 17 years. NATIONAL FINGER PRINT INSTITUTE DEPT. D FREMONT, NEBRASKA ARE YOUR KEYS THE ONLY KEYS to your shop, home, office, store, garage, ete. Why bein doubt! Don’t take chances. Learn how to reset your own cylinders so that keys that may be in the hands of old tenants and landlords or perhaps burglars will not work. Our locksmith manual for resetting cylinders sent for $1. ms iter several minutes -a with our manual you : will be able to reset aN cylinders very easily: i SEND NOW! Midwest Locksmiths, 3711-M W. Chicago Ave., Chicago, HI. À AN \ SA A a | Oe = LA oI MAKE MONEY IN YOUR WORKSHOP _ J The new 1937 edition of the Modern Mechanix Blueprint Catalog describes 125 projects that can be constructed in the home workshop and sold at a good profit. Send a 3c stamp today for your copy of this valuable book to ; MODERN MECHANIX PUBL. CO., Fawcett Bldg., Greenwich, Conn. : Better Baili—Lower Prices Canoes, Rowboats, Outboard Motor Boats, Olympic, Snipe, Comet and Sea Gull Sail Boats CATALOG FREE Save Money—Prompt Shipment—Two Factories. THOMPSON BROS. BOAT MFG. CoO. °° 230 Ann St. ( Write to ) 130 Elm St. PESHTIGQ, WIS. ecther place CORTLAND, N. Ye 134 Home Repair Problems [Continued from page 97] pasteboards and similar trash. Fires are often caused by spontaneous combustion among rags located in a closet or storage box. It is always a good idea, too, to board up all windows and doors so as to prevent ransacking. Clothing should be packed in mothproof containers and all rugs and carpets rolled up in cedar treated paper or in ordi- nary paper containing moth flakes. When possible, clothing should be packed in wooden packing cases and a liberal amount of. moth flakes sprinkled in pockets and folds of the materials. If the packing case is then nailed shut there is very little chance for vermin to attack the contents. Leaking faucets often result in rust stains ap- pearing on bathroom fixtures. Since the removal of the stains is in many instances difficult it is wise to replace washers as soon as they show signs of leaking. Where the seat of the faucet is worn it should either be reseated or else special reseating washers used. Ordinary washers will not stop a leaking faucet when the seat is worn excessively. Rustic garden furniture can be protected against wood boring insects by varnishing surface so as to check the entrance of the vermin. The varnish, being transparent, will not detract from the beauty of the furniture, but add to its appearance by giv- ing it a semi-gloss finish. Other unfinished wooden furniture or garden decorations can be treated in the same manner. Loose door hinges should be tightened as soon as noticed. Where screws refuse to take hold, a repair can be made by filling in screw hole with a synthetic wood compound. If a door sticks, the high spots should be planed down until the door opens and closes freely. Auto Engine For Marine Use [Continued from page 128] pipes welded through the case form good bearings for the shafts and save cutting the portion out of the old model “T” case. 4 The use of 14-inch machine bolts instead of rivets in the control shaft facilitates assembling. The outside control operates the same way as the lever in the model “T” car except that the cam is welded to the operating lever instead of being on a separate cross shaft. A depression in the cam will hold it in neutral position. A hardened screw end and a little grease on the cam prevents wear. With this work the conversion is completed except for painting. A good coat of paint will help the appearance wonderfully. Use about 1 quart of oil in the reverse gear of the same grade as used in the motor. A Universal joint can be made up from a front half of a model “T” and rear half of a model “A”, bolted together or a model “T” joint complete, depending on the type of drive shaft used. Be sure to keep these joints well greased. Use the regular model “A” carburetor on the motor, inserting a wedge between the mani- fold and carburetor to keep it level. A model “B” cylinder head can be used which gives slightly more power. Any standard thrust bearing can be used on the back of the motor. Forest fires not only destroy timber but clear the way for floods to do increased damage. Accept No Substitutes! Always Insist on the Advertised Brand!

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eae oe i. soe Oe en eee ee eS - ee UE eoar aya i: eam er i, | eS A. See a a . - S —- Gs 7 : . ——— ~~ z A —— 7 j ~ ~ e—a — A xx FireWalking—FactOrFable? 7 [Continued from page 133] ] eminent physicists and doctors were present, and è numerous photographs were taken at the time. 7 The feet of Mr. Bux were examined chemically and in other ways immediately before and after a n 1 3 7 k ES the firewalk. The skin was found to be soft and . & tender, and quite unprepared by chemicals. A és I A f, Ae : piece of sticking plaster was fastened to one of the but how TheWor S ost Ei feet, and, after the walk, this was not even 2 f | D f ¢ a scorched, nor were the feet of the fire walker in , er ect y eve ODE alt... any way burned or injured. The temperature of the interior of the fire showed that it was 2,552 degrees F. (hot enough to melt steel) while it was 800 degrees F. at the surface. These tests established the actual heat. Several times the young man walked through the fire and across the glowing surface. Then he said that his “faith had left him,” and that if he tried it again he would be badly burned. Immediately after Kuda Bux’s demonstration, a young Englishman named Moynagh attempted to duplicate the feat he had just witnessed. Strip- ping off his shoes and stockings, he started to walk across the fire. He had only taken a couple of steps, however, when he sprang out of the fire- pit with a ery of pain. Both his feet were found to be so severely blistered that they had to be treated by a nurse before he was taken home. A vecent pho- ograph of Charles Atlas, ider of the title “The Worid’s Most Perfectly De- veloped Man’’ -won t w open competi- tion inthe only national and wnternational contests held during the past 15 years. HEY thought, If the fire was not really hot, why was Mon- it couldn’t be \ nagh burned? And if it really was hot, why was | done—but look \ not Kuda Bux burned likewise? at me now! I C f In many of the observed cases, the såme prob- me e ne 4. eed e lem confronts us. Fatal injuries have been re- | weighing on | yo corded of those trying the feat. Yet, on the an ails for other hand, after the fire-walker has given the sports: afraid to put necessary “power” to even the Europeans who up my B. Bee ; a attempted it, they walked through the fire un- Tension!—the amazing method that gave harm d! me the body which twice won the title, ‘The Suss World’s Most Perfectly Developed Man.’ In many cases, i& is said they even walked And thousands of other fellows who have put my secret to thin ri - i1 wa! fl j ir cl i mell- work are today the envied, he-men LEADERS in any crow ahi oo AL Saar Se ee Proof in 7 Days that You, too, . can Have a Body Like Mine These cases are not unique. Instances are on Now I actually guarantee to show you PROOF’ in just 7 DAYS that T n Tog?’ ; I can give you a body that men will respect and women admire. record of modern “psychics” or mediums who | iet me make you a NEW MAN—with a a have accomplished the same thing on a small | body of might and muscle, afraid of nothing, FER, | J ready for the good things and good times of %, | scale. Sir William Crookes and others have re- | life. I'll put solid layers of rippling muscle * on your back and shoulders. ean Nulla ou ported that a medium by the name of Home went | your chest to husky, he-man size and give s e your arms and legs handsome muscles of to his fireplace, took out a burning coal, and powerful. strength. TI give you vigorous 1 ig xri 5 7 new health, too—banish pimples, blemishes, held it between his fingers, blowing upon it until | toor dietin ete.” THIS STERLING the flames licked up between them. He said: Send for FREE BOOK SILVER CUP “You do not believe the coal is really hot? Mail the coupon now for my valuable illus- BEING sn trated book, “Everlasting Health and GIVEN AWAY Touch it! Strength,” filled with actual photos, vital This valuable cup stands abaut 14 inches high on a black ma- hogany base, IT will award it te my pupil who makes the most improvement in his development within the next three months. Š è ° : e body facts and full details of my ‘‘Proof in The investigator did so, and received a bad | 7 Days” Dynamic Tension Guarantee. There's 4 wee no risk, no obligation. It's FREE. Clip an burn immediately. Then, however, Home placed | senā coupon TODAY to me personally: his hand on the investigator’s shoulder, saying l See w Non yak Ny Ord trest, m a “All right, now you can take it.” CHARLES ATLAS, Dept. 6W And sure enough he did; he was enabled to | 145 East 23rd Street, New York, N.Y. p y wane the Pree toat Your fen of € $ e s s ic Tension wi é i hold it for some time in his own hands without -give me healthy, husky body and Dig musele development. Send me š è è ok, verlasting Hea and Stre Aid even being scorched. This seems like a case of at the “transference of power,” similar to that em- | 0° ------7---- (Please print or write plainlyy “7777777777777 ployed by the natives, in their rites. PO O nt lI ere How are such marvelous powers to be ex- pla ine d? OOS css as ts a cs a iS i Tass Ms ea EE SA ind Stine When Answering Advertisements Please Mention July Modern Mechanix 135

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AMAZINGLY NEW OY Ape GREAT ‘COLOR-CODED’ RADIO-TELEVISION „EXTENSION TRAINING Developed by experienced engineers. Backed by ‘nation- ally known 5000 watt Columbia network basic broad-~- casting station KMBC. “Color-Coded”’ training cuts your training costs to the bone. Study and experiment at home. Then come ta our fine resident school for ‘four big weeks’ intensive training. You will get 90 simply worded, modern, ‘‘color-coded"’ lessons, 10 attractive “home laboratory’? manuals, 10 big shipments of experi- mental equipment including 3 inch Cathode Ray tube, bus ticket. to Kansas City and resident training. Graduates qualified to take Government operator’s license exams. Lifetime employment serv- ice. We are’ not connected with. any other Radio or (Pelevision school, Get the facts. Mail the cous pon TODAY.

{Mail in envelope or g MIDLAND TELEVISION, Inc, 29th Floor, Kansas City Power paste on postcard) g @ and Light Bldg. g 108 West l4th St., Kansas City, Mo. P & Without obligating me, send your new FREE book about the 5 Bl Radio-Television profession, “FORTUNES in FORESIGHT.” © NAMGscse Kacsenece sce es ees Ceweeei es eeeo0e600 3 eeesceeee? % Age a g AUUT Se an anaana anina se anes iS E g Cil sscscouncisicere scs Tetts ecoasavrtTesos State. vseresvoses A D a a a a a a M eee ee a

NEW WAY FOUND TO RECONDITION AUTO ENGINES FOR 95% LESS Without Rebore or New Rings, Saves Gas, Oil—Increases Power, Costs Less Than Spark Plugs. READ BELOW HOW YOU CAN TEST THIS AMAZING NEW DISCOVERY FREE OF RISK—Then Write Quick An amazing new Em aN method of recondi=- ri is 7 tioning the worn rings and cylinders of auto engines which waste gas, pump oil exces- sively, lack power and pep, is now being used successfully by motorists in place of an expensive new ring and rebore job. Any car owner can easily put it in his motor— it lasts up to 10,000 miles. Laboratory tests prove all itsclaims. SENT ON TRIAL For 10 Days to prove without risk what it will do. Car owner agents, salesmen, distributors wanted everywhere—112% to 359% profits. FREE SAMPLE for Your Car offered to those who help introduce. Be first locally—write quick —a le postoard will do. MICASEAL 600-J, 1302 McGee, Kansas City, Mo. P + ps > yt y z =P)» t a i yee : , - =- N a ey. n < dot iff Maen oN le ge 1) Sik: „ihme adare -s ai) i aa iss eee aa RT Ree file fT pis nag Ae mal bt Ck ne Se etn.

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The condenser is made from glass plates, sheets of tin foil and copper ribbon for tab connections. The glass plates can be bought from a photographer already cut 8x10 inches and are preferable to window glass because they are free from bubbles and other imperfections. To clean them they should be soaked in hot water and then scoured to remove the emulsion. To make the condenser, 132 plates will be required. It might be well to have a few extra in case some are broken or prove defective. Sixty of the cleaned plates are now covered in the center on both sides with heavy tin foil cut 6x8 inches. This tin foil may be purchased from wholesale hardware dealers in rolls a foot wide. As is readily seen, 40 feet will be needed. If it cannot be obtained in this form, a florist might be able to supply it in sheets. To fix the tin foil in place, the plates are heated in an oven, rubbed with a cake of beeswax, and the tin-foil sheet pressed on the center so as to leave a margin of one inch on each edge. Both sides of the plates are covered in this manner. Any ridges’ or wrinkles in the foil should be pressed out by rubbing gently from the center with a wad of cloth. Copper strips 3g of an inch wide and three inches long are soldered to the upper left hand corner of each sheet of tin-foil after which the condenser is ready for assembling. First a plate without tin foil is taken, then a plate pre- pared with the foil is placed on top of it, then another clean one is placed on top of the prepared plate. These plates are stacked together until five of the prepared plates have been used. A clean plate is then placed on top of. the pile to act as a cover. The unit is then bound. with friction tape to prevent the plates from separating during the in- sulating process. When all the plates have been used there will be 12 units ready for insulating. The first method of insulating is perhaps the best if it be not desirable to move the condenser very much. It consists of submerging the entire condenser in a tank of transformer oil. If this is done be sure that the wires from the individual units are above the surface of the liquid. The other method of insulating consists of dipping the edges of each unit to a depth of two inches in a hot mix- ture consisting of equal weights of beeswax and rosin. We now come to the construction of the spark gap. This consists essentially of a fan motor turning a copper or steel disc, slotted as shown on page 94. The discharge electrodes are placed on either side of this disc so that when it revolves new faces are constantly being presented to the spark. This not only keeps the metal from oxidizing but constantly circulates a current of fresh cool air between the electrodes. The motor for this gap may be of any convenient size. An old fan motor is best as it uses little current and has a fairly high operating speed. ‘The rotating disc should be at least 34-inch thick and 10 inches square. After finding the center of the piece of metal, a circle of 10 inch diameter is drawn, then one of 9 inches and finally’ one of 3-inch diameter. The metal plate is next mounted on a wooden faceplate in the lathe and a cut taken through the metal on the 3-inch circle and a similar cut taken on the 10-inch circle. The disc should now be divided with 24 radial lines running from the center and crossing the edge at 24 equi- distant points. Since the radius of a circle is equal to % the circumference, the 9-inch circle can easily be divided into six parts with a compass, each of these parts cut in half and then each part once more halved making 24 equal parts. Alternate segments between the 9-inch circle and the edge are removed. This is best done by cutting the two edges down as far as the circle and then breaking off the fragment. This is entirely permissabe since the bottom of the cut does not have to be smooth. To insulate the motor from the high tension current, the disc is mounted on an insulating hub, which in turn is fastened to the motor shaft. The disc is placed on the fibre and six holes drilled around the edge of the fibre and on through the metal. The two are then bolted or riveted together. The motor with the completed rotating disc mounted on the shaft should be bolted to a suitable base. Opposite the edges of the disc screw a piece of fibre -inch thick, l-inch wide and high enough to extend an inch above the motor shaft. These form the supports for the stationary electrodes. The electrodes are made of brass and ground or filed slightly concave to fit the curve of the disc. The side opposite the concave face of each electrode is drilled and threaded upon a #-inch brass rod which in turn passes through 34-inch holes drilled in the fibre supports in such a position that the electrodes are nearly level with the motor shaft. Strips of heavy copper ribbon are soldered to the brass rods and establish connection ‘with binding posts placed a few inches heneath the rods on the fibre supports. We now come to the final piece of apparatus and perhaps the most difficult to construct, the high frequency trans- former. This transformer consists essentially of a large eylinder upon which wire is wound in a single layer for [Continued on page 150] [Yhen Answering Advertisements Please Mention July Modern Mechanix S [l E \ | | Š TESTED SYSTEM OF DIESEL AND GAS ENGINE TRAINING To qualify for a good Diesel job you must receive training in an institution that can offer you practical instruction. At National Schools you actually work on the latest equipment, including practically every approved make of Diesel engine. You get the kind of instruction that serves your every day needs in the Diesel field after you have graduated. It’s the type of training you can “cash in” on. You are trained under the direct, personal supervision of licensed Diesel Engineers. Diese! Electric Power Generation A new feature essential to the complete training of Diesel ex- perts. Completely covers power generation. This extra course is now presented to all Diesel stu- dents without extra tuition. EASY-TO-LEARN MASTER TRAINING National Schools’ training is complete in every respect. It includes all phases of Diesel en- gines, fuel injection, gasoline, butane, propane and natural gas engines, also Auto-Diesel elec- trics, machine shop practice, bat- teries and other essentials that must be learned in order to give you well rounded-out training. LEARN IN LOS ANGELES The most delightful place to learn—Los Angeles—the play- ground of America, Fascinating surroundings. Your coach raile- road fare will be allowed to Los Angeles from any point in the EARN ROOM AND BOARD We help students obtain part- time jobs to earn room and board while learning. This service only for residents of U. S. NATIONAL i» SCHOOLS rtial Room, Diesel Engine Dept. Student Servicing Diesel Electric Unit Diesel Gene ng Unit. Diesel Converted Ford Auto > National Schools, Dept. 7-MMA, E g 4000 So. Figueroa St. Los Angeles : E H NAME carsscoceriysecose iodat to iwe ossoa AGE. cessos k a ‘ g ; ADDRESS seeooeceaosceeceeceoeacocescuescenaoseoneoeeagececoaeoanaetsebe E " i E ONYT eea ame e ea a E ea STATE. ccwcsesescs E Fon or eee Ee 137

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Turn Your Skill /nfro DOLLAR$ Make extra money in spare or full time with motor- driven woodworking tools. Opportunities in every com- munity await alert crafts- men. Hundreds of men all over the country are cashing in today. Find out how they are doing it. Send only 10c for big new book, crammed with money-making plans, ideas, drawings, illustrations — show- ing how others have increased in- come and become independent, Address Dept. M737 RI oN CEO Se 600 E. VIENNA AVE. MILWAUKEE, WIS- BUILD IT YOURSELF The Jim Dandy Cabin Cruiser The Trailer that has everything, Classy! Roomy! Easy to buildin any size with my simplified Plans and Instructions—Price $1.00. Rush dollar bill today to PPLY CO. Box 438-C WAUSAU, WIS. Over 100 pages! Beautifully Printed and Illustrated! Trailer Sug- gestions and Ideas galore! Catalogshows America’s greatest line of Trailer parts and Equipment at lowest prices, Everything from wheels to top. Rush 25c today. Satisfaction positively guaranteed! TRAILER SUPPLY CO. Box 438-C WAUSAU, WIS. PHOTOGRAPHY offers you big opportunities Get into this profitable field! Cash in on the growing demand for expert photographers! Enjoy a fascinating, profitable career. We give you individual, practical training that will qualify you as an expert in Commercial, News, Portrait, Advertising or Motion Picture pho- tography. Personal Attendance or Home Study courses. 27th year. Write for free booklet. New York Institute of Photography 10 West 33 St. (Dept. 153) New York BROADCASTING To Repair Men, Mechanics, Plumbers, Farmers, Battery Shops, Filling Sree bee Bicycle Shops, Tinsmiths, Machine Shops, Hardware ores, Cs Si fij Ua Mi ‘4 i i ki #7, dep hs A BAAN r h ky -~ $ 50 AMAZING NEW ELECTRIC ARC WELDERS 50 fst a i 8 ET — Complete RETAILS FOR $3.75 Complete Prepaid THOUSANDS OF SATISFIED USERS Prepaid Operates from any Storage Battery. Generates Tremendous Heat. Welds All Metals. Makes Permanent Repairs on Auto Bodies, Fenders, Radiators, Sheet Metal, Castings. Cost Practically Nothing To Operate. This is a Real Welding Tool. Well Built To Work Perfectly and Fully Guaranteed. DON’T DELAY. ORDER TODAY. WOLF EQUIPMENT CO., FAR ROCKAWAY, NEW YORK, BOX 526 MAKE GLAZED CONCRETE PRODUCTS Make 2,500 designs garden vases, jars, birdbaths ~ out of sand and cement without molds, power or ® costly tools, and glaze them in colors like clayware. j Tiles, wall glazing, statuary, novelties, giftware. No experience needed. Money-making employ- ment. Send 10c for booklet, color plates, cost data, details, NATIONAL POTTERIES COMPANY 13 W. 26th St., Room 26, Minneapolis, Minn. A responsible job at good pay is yours if you will pre- pare for it now at Lincoln. Aviation needs men—is regu- larly giving profitable employment to properly panes Lincoln Graduates. More are needed 4 NOW. Train at LINCOLN—Through Lincoln Government Ap- proved Training, you’ll learn to fly many types of air- planes .. . to overhaul and repair any type of aircraft en- gine. With a few short months of Lincoln Super-Training, you'll be COMPLETELY READY for YOUR job in Aviation. Airline Pilots get up to $700 a month; Co-Pilots $250 a month, Licensed Mechanics get up to $200 a month. Lincoln’s complete training prepares you for any grade of Pilot’s license including Transport; or for Government Mechanic’s License. Ideal year ’round flying conditions. Write now. State age. LINCOLN AIRPLANE & FLYING SCHOOL, 403-G Aircraft Bldg., Lincoln, Nebr. Taking “Instant” Photos [Continued from page 111] the speed of professional direct-positive outfits used on the midways of carnivals and fairs. Any light-tight box that is large enough to hold the developer and fixing-bath trays, with room for manipulation of the paper with one hand, will be satisfactory as a darkroom. For fast work and utmost convenience, a box of up to 10x10x15 inches in size is ideal, for it permits the use of small shelves in the upper part for storing your stock of bromide paper. -Such a darkroom may be placed on the ground or on another box underneath the tripod if you wish. If portability is a consideration, you may use a large cigar box approximately 9 in. long, 5% in. wide and 5 in. high. This is large enough for two 4x5-inch porcelain or hard-rubber trays. Glue narrow strips of black velvet around the mouth of the box so that light cannot enter, using two hasps to hold the lid down while developing. A slot is cut in one end of the dark- room to permit of introducing the film holders part way inside for removal of the exposed bromide paper, and likewise for reloading. After lining the slot with a rather wide strip of black velvet, test it to see that no light can enter. All testing is done in a dark room or closet by plac- ing a light inside the box. As has been mentioned, one hand is introduced inside the box so as to manipulate the paper during developing and fixing. Cut a hole in the front, just large enough to admit the hand, then glue in place a light-tight sleeve in which is sewed a piece of elastic to hold it snugly around the wrist. Any heavy black cloth through which light cannot pass is satisfactory. A convenient alternative is to secure a pair of heavy sleeve protectors, of the type used by store clerks, and telescope one within the other. These are al- ready provided with elastic at each end. While it is easy to get good results with this simple process right at the start, the beginner is advised to avoid harsh and contrasty light on the subject, as the bromide paper does not have as much latitude as regular negative materials. Any portion of the negative may be enlarged by bringing the camera nearer; provision for this is made for this on the negative holder and the negative may be slid forward, brass pins marking the position for regular work. Wash and save all negatives in anticipation of orders for more positive prints; in fact, it is a good plan to stamp your name and address on the back of the paper beforehand. Many of the herbs for seasoning can be grown in kitchen window boxes in the winter. Seeking suitable material for spinnerets, the rayon industry in this country has found a gold- platinum alloy the most satisfactory. 138 Accept No Substitutes! Always Insist on the Advertised Brand!

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At) Tee —— Oe eg ee ge eS ae DE wg Pun -o ES ee | it—. x BURIED TREASURE! | Find ft With the New GOLDAK RADIOSCOPE Money Back Guarantee! Locates any metal in- cluding gold and silver sealed in glass. Guar- anteed to detect deeper than any other device, regardless of price. Mast advanced scientific design, based on original Radio Balance in- vented by Chilson. Write world’s largest manu- facturer of successful mineral locators for interesting information. = THE GOLDAK CO. 1031 SouthBroadway, Dept. M, Los Angeles, Calif. As "a ts l x l , 7 7 f Ea 2) TO $ UCCESS 8 EJ DON'T COPY - LEARN TO ORIGINATE! RAYE BURNS will teach you HOW to CREATE 8 ORIGINAL CARTOONS at home that you can SELL! Course has 26 lessons and 600 illustrations, “ ` aaah Send name and address for free details. Only...- RAYE BURNS SCHOOL, Dept. F-X, Box 2194, CLEVELAND, OHIO rs $ GA Learn Profitable Profession @ in QO days at Home . Salaries of Men and Women in the fascinati ros \ fession of Swedish Massage run as hich as £40 to ‘ $70 per week but many prefer to open their own of- i fices. Large incomes from Doctors, hospitals, sani- tariums and private patients come to those who qualify through our training. Reducing alone offers rich rewards for specialists. Write for Anatomy Charts, sample les- son sheets and booklet—Thsy’reFRER. THE Coliege of Swedish Massage oo »-*” I6WN.Ashiand, Dept.e-58, Chicago cio £ Successor to National College of Massage) AND PAY YOU UP TO $10.00 IN A DAY? Amazing new idea! Wear this splendid suit and T'I pay you for it if you follow my easy plan and qualify. Choose suit from fine woolens, union tailored to your measure. Just show it to your friends. Make up to $10 in a day—easy—representing big nationally-known tailors ing house. No experience needed. TUAL SAMPLES FREE! Write today for details of sensational new plan and actual Samples. SEND NO MONEY. H. J. Graves, Pres. STONE-FIELD CORP. 1300 W. Harrison, Dept. U-737, Raise giant patented mushrooms! We supply materials and instruct with pictures. Our 25 Coast-to-Coast branches buy all crops. Big FREE book, photos tell if your cellar, shed, barn, etc., suitable. Write today. (Established 190§.) UNITED MUSHROOM COMPANY 3848 Lincoln Ave.. Dept. 316, Chicago a Poa DAA WRITE FIC INSPECTOR WIDI: Y RAILWAY AND BUS LINES DEMAND MEN WITH THIS SPECIAL TRAINING CONSTANT DEMAND for active, reliable men—19 to 50—as Passenger Traffic Inspectors, Our simple, home-study course trains you quickly, and upon com- pletion we place you at up to $135 per month, plus expenses, to start, or refund tuition. Fascinating work; healthful (outdoors). Travel if you like. Steady advancement with experience. Free Booklet gives our 18-yr, record. _ STANDARD BUSINESS TRAINING INSTITUTE Div. 6107 Buffalo, N. Y. MAKE ORDINARY STONES LOOK LIKE PRECIOUS GEMS Everyone picks up pretty stones on their hikes or summer camps. Don’t throw them away! With the new, inexpensive Johns Gem Cutter YOU can polish them for a collection or for jewelry. ASK US HOW-—Send for folder “X.” THE JOHNS COMPANY, SAPPINGTON, MO. a =. . = ENGINEER DOBE, Div. B473, Libertyville, Iih 5 a Send me your free book, ‘‘Successful Draftsmanship” and ex- ® a plain how you will assist me to a good position as a draftsman. a . m = Name_..--—-----—----—----— wows ARB cect a E ADUS mam a a a i. Peb ON E rarna VEA Ooit sae oe ED te ee ee E 2 py 87 \ i a L ma 5 it = ý - = 3 ia Are you in a rut, tied to a factory job, with little or no prospect for advances ment? Will you be doing the same thing 20 years from now? Pe will you train for a better job, more pay and pros- perity ? Prepare now, toen- joy everything that bigger earnings make possible. The Road to Advancement RAFTING In every walk of life practical training in DRAFTSMAN- SHIP will prove valuable. Even if you don’t accept a job as a DRAFTSMAN, you will be money ahead by taking Engineer Dobe’s Course. You will be amazed at the speed with which you can learn in your own home in your spare time by Engineer Dobe’s PRACTICAL METHOD. JOBS NOW OPEN In all industries, Drafting leads the way. In Aviation, Electricity, Building, Machinery, Automobile, Draftsmen must be used, and their work comes first. Recovery in industry and building is definitely on the way. Many trained Draftsmen will be needed on better jobs at better pay and shorter hours. Prepare NOW ! Learn at Home From an Engineer I will teach you my practical method that has been success- ful with thousands since 1900. I will furnish you with all tools and a drawing table. I will teach you in a very short time by mail in your spare time until you actually have 2 desirable Draftsman’s job, or prepare you for better pay in the job you now have. No High School or previous expe- rience needed. You must be entirely satisfied with my personal training UNTIL COMPETENT and until assisted to a position, R MONE K. Star z and get the training. Prepare Complete Outhit Size 20 x 25 inches TODAY! Time is money! FU Be, B is ei E D Don’t delay! No obligations! for more pay and a better job. Free Book. Send the coupon below When Answering Advertisements Flease Mention July Modern Mechanix 139

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* 5 ~~ à >) i f catra Aare, rim o eTa SnI ~a ae ibe ae on netic att Oe ee | ee PT pee ese ie Bem or eee We supply Electrical Equipment and Appa- -e silty si: 8 : ratus at no extra cost to help you learn Prac- tical Electricity in your ce a Shop. No EQU | PMENT revlous experience or advanced education is foe sagary. oney back if not satisfied. RIGHT IN LO] 4} > Send the coupon for full information on this NEW, EASY WAY TO BETTER JOBS AND GOOD PAY, Lifetime FREE Employment Service to Graduates. jy ee hs eee ee ee se ee S E E G) ELECTRIC INSTITUTE, Dept. 47H, , Hinsdale, Illinois y Send Free Book and Full Details on Your Home Shop Training, i MINERS S555 5 cies SiGi5S.B6 Psi0 A nandean os keora be P e AA A | a E O T S E a 7 OD Nay Seale 4a NCL Up. cs0:0 aco-gidlnny se tere Catena te SN rs Taan EES Eies t Earn While Learning at Home Television, Photo Electric Cells, Public Address PHILCO Many R-T-I Trained Men CROSLEY make up to $75 a week and ZENITH more in full-time radio jobs— $5-$15 in spare time alone. GRUNOW More trained men needed. f and 46 Learn at home by quick, easy, other R-T-I WAY. Endorsed by 50 ; Ayy- N AE big concerns. Write for big mfgrs. Opportunity Boo FREE. endo RADIO and TELEVISION INSTİTUTE, inc., 2130 rse Lawrence Ave., Dept. 3-B, Chicago, Il. i | UTURE Demand for trained aircraftsmen in Southern California plants is increasing and already exceeds supply. Curtiss- Wright Technical Institute, Aviation's foremost and oldest school, is located in heart of this activity and specializes in Sheet Metal, Master Mechanics and Aero Engineering. (No flying involved.) Graduates are obtaining immediate employ- ment, Write for details NOW. Curtiss-Wright Technical Institute, Glendale, Los Angeles, Cal. Dept. MM-7. FULL SIZE, Sturdily Con- structed Field glasses that wear like spectacles, Enjoy “front seat view”? all sporting events indoors and outdoors, Powerful lenses—light weight yet strong—Beautifully fin ished. Separate eye focus and width adjust- ment. Sent postpaid for $1.98 or C. O. D. plus postage. D HILL-VOLIN CO., Dept. 51 5248 Drexel Avenue, Chicago, Ili. DISC WHEELS equipped with 10”x23%” \, (GOO DRICH-GOODYEAR-FIRESTONE) Kee Balloon Tires offered at LOWEST PRICES INS | ASS SS Also larger tires and wheels— | 5237 Lake St. ested ineimproving their Motors, ete. BILD-UR-OWN DEVICES Dept. 77 FREE TO THOS work through the use of fine power tools——a copy of the 48-page 1937 catalog describ- ing and illustrating the latest Driver Engineered Power Tools and accessories. Learn what it means to get your money’s worth! Write for catalog to-day. WALKER-TURNER CO., Inc., 577 South Ave., Plainfield, N. J. TODAY FOR PRICES Chicago, Il. home craftsmen inter- DRIVER Cnginecred POWER TOOLS 140 ee ee A Black Gold From Alaska [Continued from page 70] smaller lakes in the vicinity. I took samples back to Barrow and began asking questions.” The existence of the oil lakes was no secret to the Point Barrow colony. “King Charles” Brower, who has reigned over a trading post there for fifty-five years, knew about them. “But the stuff’s no good for anything,” he told the soldier. “It’s seepage oil, and it won’t burn. Too heavy.” Sergeant Morgan was without equipment to ex- periment, but he had a theory that he meant to try some day. He kept it in the back of his head. His quick-thinking and courage at the time of the Will Rogers and Wiley Post plane crash brought him more attention, a promotion, and a furlough. Leaving the Arctic Coast with his wife and two children for the first time in many years, Sergeant Morgan did not forget to take samples of the strange black stuff from the lakes of oil. On a 12,000-mile motor trip over the United States, he kept thinking about his samples, but it was not until he returned to Seattle for tem- porary duty with the Eighth Signal Service Com- pany that he really went to work. Here, he had a fine laboratory, serving Uncle Sam’s Alaskan communication system, at his dis- posal. His first step with the Arctic oil was to try distilling it. Initial results were not too en- couraging, but he kept busy for many weeks, in- terrupting his experiments only a couple of hours one day to receive the Soldier’s Medal, highest peacetime military award, for his valor in the 1935 flu epidemic. Finally, replacing distillation with a simple boiling process, he found that the oil separated at a comparatively low temperature, about 250 degrees Fahrenheit. The oil was drained off and, when analyzed, proved to be about equal to ordi- nary commercial crude. And—a surprise to Mor- gan!—the 50 per cent residue looked good enough for briquettes. Before crying Eureka, he had the whole process checked by experts, who pronounced it entirely practical—so practical that the Bureau of Edu- cation of the Department of the Interior plans to install a plant at Barrow to be operated by the Eskimos themselves. | “This means,” Sergeant Morgan says, “that the main obstacles to development of the Arctic Coast are removed. The oil will be used in simple gravity feed burners by whites and Eskimos at Barrow. The briquettes, which compare with the best commercial grades in the States, will be sent to more remote points. Besides giving warmth and light, the new plant will make it possible to thaw the ground and mine the mountains. Electric fences on farms should be used only if the hazards are understood and if reliable equip- ment is employed, lest children or others get serious shock. Accept No Substitutes! Always Insist on the Advertised Brand?

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OPERATE YOUR OWN Coil Cleaning —Aa in een BusinesSe HERE IS YOUR G: OPPORTUNITY Build up a PER- MANENT, prof- itable business of your own. Areal chance togetinto one of the newest greatest Money- Making proposi- tions EVER pre- sented. Establish a Beer coil clean- ing route, The : > new Wizard complete motorized eamp- a ment gives you a Big Steady Weekly cash income. WE FURNISH EVERYTHING to start you immediately. Taverns, Clubs, Hotels need this improved service. Only a nominal in- vestment required. Get the FREE COMPLETE DETAILS OF OUR PROTECTED TERRITORY PLAN, Write to us TODAY. RUSH! BRASS PRODUCTS, INC., 228 N. Clinton, Dept. 137, Chicago ee) a SP E al ely Ee TRAILER ENGINEERING == {Second Edition) TA BRAND NEW BOOK © To Help You Buy or Build Proven plans for 10, 14, 17, and Tells you about bob, roll, weave, snaking, nose diving, rear vision, Ackerman steering, tandem wheels, tow car balance, trailer balance, all State laws, American coaches, English coaches, plumbing, wiring, brakes, step action chassis, parking jacks, weights, furniture, ironing the tow car, every engineering detail. Get unvarnished trailer engineering facts before you buy or build. Order NOW. $1.00 postpaid, $1.15 C. 0. D. RAY KUNS, Dept. 7, 8 Eastwood Circle, fi f Tm |; aN 14 chapters, 130 illustrations. 21 foot trailers. Cincinnati, Ohio No JoKE To BE DEAF » =Every deaf person knows thata } Mr. Way made himself hear his watch tick after peing deaf for twenty-five years, withhis Artie ficial Ear Drums. He wore them day and night. $. They estopped his head Pea noises. They are invisible i SaN o ¥ andcomfortable,nowires or batteries. Write for & TRUE STORY. Also ; bookleton Deafness, Artificial Ear Drum THE WAY COMPANY 741 McKerchey Bldg. Detroit, Michigan AT HOME You can learn by our modern and original system of instruction every part of the Watch repairing Trade at home. You can earn money while learning and prepare yourself for a well paying position or start in business after completing our course of instruction. Good watch repairers are in demand and generally earn very good salaries. For par- ticulars apply to the WISCONSIN SCHGOL OF WATCH REPAIRING 524 E. Mason St., Dept. C, Milwaukee, Wis. ONAN ALTERNATING CURRENT” PLANTS furnish same as city current anywhere. Operate on gasoline. Run Radio, Water System, Refri- gerator, all Appliances. Complete, ready to run. _ SIZES 350 WATTS UP Easy to install. Available from stock. Ideal for Farms, Camps, Lake Homes, Commercial use. Sizes for any purpose. Write for details. ' D. W. ONAN & SONS 1667 Royalston Ave. Minneapolis, Minn. WHOLESALE RADIO SERVICE CO., Inc. \ 107-G Sixth Avenue, New York, N. Y. FCC ca on a E AE e When Answering Advertisements Please Mention July Modern Mechanix -a Sh Aa S, - : >» . j% a a ‘a 5 "hs WI Sear? -maa t 50 ~A bò A > at ue Tia ee MPT a ee ee FOOT TCH : Sores Itching Waton Blisters Cracked Joes DONT PAY UNTIL RELIEVED Send Coupon According to the Government Health Bulletin No, E-28, at least 50% of the adult population of the United States are being attacked by the disease known as Athlete’s Foot. Usually the disease starts between the toes. Little watery blisters form and the skin cracks and peels, After a while the itching becomes intense and you feel as though you would like to scratch off all the skin. Beware of It Spreading Often the disease travels all over the bottom of the feet, The soles of your feet become red and swollen, The skin also cracks and peels, and the itching becomes worse and worse. Get rid of this disease as quickly as possible, because it is very contagious and it may go to your hands or even to the under arm or crotch of the legs. Most people who have Athlete’s Foot have tried all kinds of remedies to cure it without success. Ordinary germicides, antiseptics, salve or ointments seldom do any good. Here’s How to Treat lt The germ that causes the disease is known as Tinea Trichophyton. It buries itself deep in the tissues of the skin and is very hard to kill. A test made shows it takes 20 minutes of boiling to kill the germ, so you can see why the ordinary remedies are unsuccessful. Tl. F. was developed solely for the purpose of treating Athlete's Foot. It is a liquid that penetrates and dries quickly. You just paint the affected parts. It peels off the tissue of the skin where the germ breeds, Itching Stops Immediately As soon as you apply H. F. you will find that the itching is imme- diately relieved. You should paint the infected parts with H. F. night and morning until your feet are well. Usually this takes from three to ten days, although in severe cases it may take longer or in mild cases less time. H. TF. will leave the skin soft and smooth. You will marvel at the quick way it brings you relief; especially if you are one of those wlio have tried for years to get rid of Athlete’s Foot without success, H. F. Sent On Free Trial Sign and mail the coupon and a bottle of H. F., will be mailed you immediately. Don’t send any money and don’t pay the postman any money, don’t pay anything any time unless H. F. is helping you. If it does help you we know that you will be glad to send us $1.00 for the treatment at the end of ten days. That’s how much faith we have in H. F. Read, sign and mail the coupon today. GORE PRODUCTS, INC. M.M. 895 Perdido St., New Orleans, La. Please send me immediately a complete treatment for foot trouble as described above, _I agree to use it according to direc- tions. If at the end of 10 days my feet are getting better I will send you $1.00. If I am not entirely satisfied I will return the unused ee of the bottle to you within 15 days from the time I receive it. NAME ` CITY _—— Å- ee ee ee l į į į ee į nmnams a PEA -= - we =e -E O a n n o a a a a a a a a a M M M aa a l l a 141 Pa m m mm m a a m m m M maY = Ta Bee : ê e 8 j m ae f>

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INVENTORS PATENT YOUR IDEAS SEND FOR FREE BOOK =e HOW TO OBTAIN A PATENT Written by a Former Member of the Examin- ing Corps (1922-24) of the U.S. Patent Office. If you want to profit by your idea, you should S= take steps to apply for a U. S. Patent a - once. Your first step is to get this Free Book. This interesting illustrated book contains valuable information you should have. It tells you fully how to obtain a patent on your idea in the quickest way. With this Free Book you will also receive a “Record of invention” form on which you can easily record your idea. Personal and Confidential Service: Your case will be personally handled only by 2 Registered Patent Attorney who is also a Former Member of the Examining Corps of the U. S. Patent Office. munications confidential, MAIL COUPON TODAY for FREE PATENT BOOK and RECORD OF INVENTION Form CARL MILLER All come REGISTERED PATENT ATTORNEY FORMER MEMBER EXAMINING CORPS U. S. PATENT OFFICE @ 1638 Woolworth Bidg., Dept. 77B, New York City a il MILLER BUILDING, Dept. 77B, WASHINGTON, D. C. E Please send me your Free Book, *‘*How to Obtain a Patent,” and g : your “Record of invention” form. p | i NAME SCOKCOHOSPCHOHORSHH SETHE HESS HE oO EHHE Eat EOSeeeeseeese a i 6 B ADDRESS CROCS ORO EHH T Eee eH eewEeEEHEHEHEEEHOeHEO, E p E E E N ene es AMATEUR CARTOONISTS WIN $2500 Wanted—Amateurs with humorous ideas. No drawing ability necessary. The amateurs of today are the professional care toonists of tomorrow. Ideas judged and prizes awarded by Applause-O-Meter test before movie audiences. Everyone has an equal chance. 26 cash prizes in all. Rush name on penny post card for “Valuable Tips on How to Make Money With Simple Cartoons and Humore ous Ideas’’, Cash Prize Entry Blank and Rules—SEND NO MONEY, a x CARTOONISTS’ EXCHANGE, Dept. 357-B, Pleasant Hill, Ohio PARKS AIR COLLEGE PARKS AIRPORT EAST ST.LOUIS, ILL; Offers you college education majoring in aviation Four 96-week courses lead to B. S. degrees in Professional Flight Aviation Operations, Aviation Mechanics, Aeronautical Engineering. 100 acre airport. 14 buildings. 33 in faculty. 254 enrolled. 5,800,000 miles fight training. 1.548 planes. 523 engines repaired and rebuilt in shops. Graduates with all leading aviation companies. Dormi- tories, dining hall on field. Summer term July 5th. Catalog. Write 10th YEAR parks AIR COLLEGE. EAST St. LOUIS. ILL. Assemble This KI-YAK at Home | @ For VACATION OR PROFIT 516. | : a Weighs only 20 Ibs. gear CARRY IT ON BIKE OR BY HAND Boy BOYS—see how easily this 51% year old young- ster carries his MEAD K1-YAK! “What fun you'll have with one—AND—you can assemble it YOUR- SELF at home in a few hours from our num- bered, cut-to-fit Construction Kit—and SAVE HALF the factory-built cost. Tell DAD about this educational project—and the FUN it will bring you during VACATION! RUSH 10c NOW for Circulars showing 57 beautiful photos of Mead Ki-Yaks—sailing, paddling, and with motor —lLow Introductory Prices, $6 Gift Paddle Offer. URRY MEAD GLIDERS, 15 S. Market, Dept. M-77, CHICAGO. $6 PADDLE GIVEN with your CK-Ki-Yak —tf you hurry ! Accept No Substitutes! He Beat Oyster At Its Game [Continued from page 73] gelatinous film coating which had raised the ire of hot-tempered ladies. In its place he substi- tuted a durable, clear lacquer. Step by step Carl Pfeiffer worked out a suitable technique as a laboratory demonstration. And then he evolved the mass production methods. In his plant at Peekskill, N. Y., he soon had 700 girls engaged in making beads, coating them for pearls, and stringing imitation pearls into neck- laces which defy detection except at the hands of experts working at close range with powerful magnifying lenses. This mechanical oyster plant has turned out hundreds of thousands of neck- laces, millions upon millions of imitation pearls. Once considered the adornment of first ladies of the land, the pearl necklace has become the proud possession of even the most humble. The imitation pearl gets its sheen from the sev- eral coats of fish silver or essence d’orient com- posed of tiny particles of the very tips of sardines or herrings. These fish scale particles may be compared with the powder on the wing of a but- terfly, which provides such wonderful iridescent hues. Carl Pfeiffer found the most suitable fish scales to be those of a small herring caught off Newfoundland. Forthwith his organization went into the fishery business to insure the source of supply. One of the many obstacles to be overcome was the mixing of essence d’orient, a water solution, with the clear lacquer. The French had been us- ing gelatine, but Carl would take no chances with ladies’ tempers. He worked for months develop- ing a means of mixing those seemingly unmixable things, and finally succeeded in obtaining his in- destructible coating. The original technique of coating was simply a dipping proposition. Beads were mounted on toothpicks or metal rods stuck in cakes of soap or placed in holes bored in wooden disks. Inverted, the beads were dipped in a basin of pearl lacquer. Girls held the soap cakes or disks in outstretched arms and twirled them about to even out the coatings and hasten drying. The scene might have been a ballet school. Hard-headed Carl soon sub- stituted a mechanical means for that twirling act. Today the beads are still dipped in a lacquer bath, 100 at a time, but the disks are placed on a con- veyor which twirls them about and carries them for a 20-minute ride about a warm room, deliver- ing them back to the dipper ready for the next dip. The more select beads are sprayed with an air brush, one at a time. The finest beads are given as many as fourteen coats. The lacquer may be colored or otherwise varied for any de- sired hue. So much for the coating. But what lies under it? The cowboy did away with the alabaster ball shaped on a lathe and drilled for the hole. He substituted glass. But how did he get the hole in that glass ball, for stringing or mounting? [Continued on page 150] Always Insist on the Advertised Brand!

Page 143

INVISIBLE INK. CAN BE READ

WOW! Whata barrain! Rea? genuine Field Glassua With six power mag- peg nifications Center . uA" . piece quick, one Se) finger focussing. Permits full, un- hampered, two eyed vision that fives remarkable scope sand clarity. Swell for nuture Stu» ; ay, hiking. sports, and Roe i POONA one erR tear A omplete with tord. evs s rece packed in lox, dniv29e knife, one hand throat grip, $ A Spanish Athletes | defense against two assaill- (Bull Throwers) Cer, | anis. stomach throw, secret tstcate; Go.d Diggers & Grafters Certificate: thumb knockout, nerve One Armed Drivers & Neckers Certificate; Ki- | pincles. and numerous others. bitzer’s Certificate; Death Certificate; Birth | Learn to protect yourself un-e Certificate; Arrest Warrant; College Diploma, | der all circumstances with Dog License; Gold Mine Stock Certificate; | nature's weapons. Fear no Divorce Certificate; Air Pilot's License; Doc- | man., guns or knives! ‘'Scien- tor’s Certificate. Only 10c each. 3 for 25c, | ce of Ju Jitsu’? Only 30c. Sterling Silver, $1.00.

Large size, nice. Berinted with seal, surtable for framing. Hand one of these to your friend and he willneverforgetyou! -our choice: Liar's License; Boot'eggers Diploma; Marri-qe Certificate (it looks real); Lias & graft- her's Certificate: Gos_ siper's Certificite;

fee Pe meee Meee oe Na ee as

bers, lets, astrolor. etc. Price 25c, Smart, snappy. Just what every real boy is wearing, Cool and comfortable, White Twill Yacht Cap, with Dlack olleloth penk, sweat band, gold hraid and brass buttons 25 with anchor, Price.. c White Duck Yacht Cap, sup- erior quality duck, white cel- luloid cap. gold cord, brass buttons and red, white and + blue anchor on front. Stəte 3

Il loots like adeardly wenpon, butitis merely a novel Cigar- ette Case. Better than the veal : thing in many an awkward en. counter, Great fun*‘sticking up’’your friends. They squirm and protest. Pull i the trigger and the slide flies op: 25€ 4 en. disclosing cigarettes. Price [ co ag | 326 Jokes & Rid- dies, 25 Tricks. 10 Parlor Games, i 73 Toasts, 13 t\utomatic repeating slingshot | Stories, 105 Mo- nat will fte 150 shots with | ney-makingSec me loaving! Designed for ge- | rets, 22 Mono» ‘uracy. Bulls eye every time. | Jogs.21 Puzz!es. fF oxtremely powe ful and hard “itting—wi i page magazine. More powe“ful | Names & their Meanings. 10 Picture, than anairrifie. Sturdilycon. | les. 37 Amusing Exneviments, Dea

leather shot holder and thick lively cocds. 150 BBs, Slingo, *he automatic slingshot, only 25c. Tube of 200 Copper coat- zd BB's, 10c. Bell ringing rarget, 30c. TEER GO E Two of the latest, newest models ae “wow out—50c and $1.00. Pattern- = ed after the latest type of revolver.. Shoots “g 22 caliber blank cartridges obtainable every- where. Handy protection against _ burglars, ‘tramps and dogs. Fine for 4th of July, New Wears, stage work, starting pistol, etc., ete. Looks Like A Real Revolver Strongly con- > structed with a flashy nickel fin- ish. Has dip barrel that allow3 the cartridges to be loaded in a second, Medium size, Large size $1.00. Blank Car PEN SAYE AUTORE tridges 50c per 100. Holster hipped By: expres. (Cowboy Type), 50c. SHIPPED id. Pri 5.50. Uses spe- Dor eee iddes: PSC pet 200: BY EXPRESS, NOT PREPAID.

9 Men Morris, Anagi‘ams., 25 card Reichs. Crystal Gazing, etc.. etc. Only

pist

Shot Automatic Blued steel §-shot auta- 7 matic blank pistol, Fires blanks only. Looks exactly like ex-

LUMINOUS PAINT, when applied toan object, emits rays of white light, render- ing it visible in the dark. The darker the P night-—the brichter itshines, Simple to a Vix use—you can do it! Apply some to the aJi jX dial of your watch so you ĉan tell timeat =. night. Paint pushbuittons.switches.any thing, everything with it. Small Bottle, 2%c,

DEPT. 119

BROADCAST thru your radio TALK - SING - oS your voice On programs comin h ; SQ BROADCAST radio set—make announcements fon cee te i the house—inject wise eracks, Josh and mystify friends. Jmitate radio stars, practice crooning, singing, radio acting, ete, Do a “Ben Bernie” or a “Rudy Valee.” World Mike Made especially for home use, attached in a jiffy without tools, Not a toy. Put on your own pro- |S i thru your own radio, grams at home, parties, club af-, | BAX fairs, ete. Barrels of fun!, Easy Price Posteatd 250 Six Power | Open Any Lock

Big jumbo size, with a flashy entblem, surrounded: by the American Eagle, Like the U.S. Government men wear! State type aud size. Silver Finish, 250€

OLD MADGE’S DREAM BOOK Pisams, fortunes, oracles, fortune telling tab- marriage, divorce & births.

n little instrument, fits in the mouth out of y sight, used with above for Bird Calis, ete. Anyone can use it, Never fails, A complete book with f fuli course on Ventriloquism together with 10c the Ventrilo. Sent postpaid for only.......

Problems, Comic recitations. Funny Readings. > ad aa i instantaneous. t ae : : p<. $ 1 package of printing pa- : rith non slip Sve ¢ abet. Shadowgraphy. Fortune ; YZ structed with non slip Si ler. Fortunes with Cards, Crystal, Tea Cup. |glass top, and a supply of chemicals for de. | etc... Hypnotism, Ventriloquism, Cut-outs for |veloping, fixing and turning out the finished Boal Checke:s. Chess, Dominoes, Fox any Geese. tpicture, full printed instructions so plainly || over 75 illustrations, plans & blueprints,

, | wee JOHNSON SMITH & CO JAPANESE ROSE BUSHES AN eee y r r NEW CATALOG, or 25c for tho DELUXE i i lanted, d when three N EoiN ith permanent cloth binding. Bigger and better years old. the push isa mass of tnan evor: inaw items—different Items—things that you never | roses. Three aCe UARANTEE E TT < eee ou existed. : Medium size $O0c, Large size $1-00 postpaid, u as token seeds, books, puzzles, etc. STAMPS ACCEPTED. SIZE ROSES. Blooms regularly. Packet. 20c HOW TO LOVE AND BE LOVED. An Interesting and complete book on this passionate subject. Read and profit. ONLY 100 POSTPAID,

Porm ite YW PLO sae Remarkahle results—simple opera- tion—Iow prices! 25 te 600 meters, Gets pel ice calls, foreign stations anywhere, code, short wave, for- 2 eignand domestic broadcasts, etc, s -a With remarkable volume and effi- O uciency. Each set complete without y Kc

ts from any part of tube, phone, battery or aerial. one. ean SATTERY SET. 00! eadphone vyol- ume. Complete Kit. $1.55 Wired ready to operate $2.36, SUPER ONE TUBE BATTERY SET. Gives better volume & reception. Complete Kit $2.00 Wired, ready to operate $2.75, ELECTRIC TWO TUBE. Oper- ates on house current. Uses no ; batteries. Powerful, sensi- tive, selective. Kit, $3.00. Wired, ready hand. Guaran-| | t@_OPerate. $3.75. aD ES ees Tod | CEEVNV ANAS SE a CRYSTAL 7 Com ETS] | ALIVE PET __ s tnis isaradioin itselr as itis poss-

ELUXE MIKE Large, substantial, all- metal mike, Practise ra- dio singing. broadcast- ing, programs, etc.,

Reproduces voice im clear tone with- distortion.

htc w Ret reception with it alone x À i Es within 25 mules Oe i station or up to miles under food con- WATCH if CHANGE COLOR! 4itions). All vou need | Get one of these most wonderful of all crea- is an aerial & ear | tures. Watch it change color, Study itshabits. [=i phone. Completely | Wear one on the lapel of your coatas a curiosity. PTE assembled & wired | Shoots out its tongue to catch _ flies and tnsects fmm With supersensitive | for food. No trouble to keep. Can go for mm crystal. stand, base. | months without food. About 4 in. lon + Ship- PEAU crystal cup. arm with | ped to any address in USA by mail. e guar- cat's whisker, ete. Reception guaranteed. 25c ‘ antee safe arrival and live delivery. Only 25c ‘MIDGET POCKET RADIO $1.00 | Listen to Music Programs and Sports Everywhere You Go! Loud Tone Beautiful clear tone while you walkf The amazing midget pocket radio gives you all the entertainment of @ radio wherever you are—in the country, office, on a boat, in a car, hotel, jm bed, on bicycles, ANYWHERE and EVERYWHERE. Size of a cigarette package, yet it operates perfectly, Beautiful clear tone. Range, 50 miles. No static or noise. No batteries, ne tubes, na crystals to adjust, just one moving dial to locate stations, New sensitive rectifier and high efficiency design. Not a toy. Price Postpaid $41.00. Earphone, 890c. Phone & Radio Set $1.79. New Vest Pocket |g Eri TAP DANCE | a Feet ta) : Machin : Why envy theeasyrhythm and ae prace of Adds, subtracts, multiplies, di- Step'n Fetchit, Fred Astaire iaee, Dien Wontan. apaes E EE ehine. en mi Z f. Sby i Si Simple and accurate. NOT A PRICE course Dy Fret Wt saan TOY: Exisy to operate. No keys specia ‘ae neces ave to punch, no lever to pull. Total H smar J veryt i ysi bs always visible, Guaranteed for 9 ping. Thew oie p nis years. Lightning calculator and tapping. eat ou time saver. Constructed of steel tune with your feet. ensuring strength.durability and 310 lilustratione

g in’ Tyree Te Paria EL)

ADDITION — X ; 7 ; lifeilme. Ti reliability. Lasts a li Hostessesloveit.Friends adore const) Compact and light. Weight ice wit. Besides. tap dancing is not IVISION Will fit rightin yest pocket only invigorating and enter.

taining but is alsoa healthful exercise for making the limbs sup. ple and giving a‘*‘springy’’ feeling of fitness to the whole body. Pros motes slimness nature's way—no pills, drugs or dieting. Readers say: foi wonderful bene at Thank you ora ng ancing tomy accomp- ric radio, short wave : ’ t i ai radios iets om bilidinie lishments."’ Price 25c postpaid. television set. With a ` i; ~A television set you can Learn *f OVER 101 ILLUSTRATIONS SEE as well as HEA oy LATEST STEPS. Be ponu- reception. Tells how a simple home set may be built. Book lar. Good dancers are al. waysadmired—always pops plans. eic. ONLY 10 CENTS. ular guests. Partners wel- J £ome them eagerly. Thenew- est, smartest steps without a teacher. Don't make excuses when the music Starts. Get lots of fun from parties and dances. < Ifyou want to become a verfect dancer, learn to dance at home this new easy way, BOOK TELLS: i endean he eavried about without inconvenience. 3x6in, Price, . $1.50 Radio & Television Boo How to build inexpen- sive crystal sets, elec-

1 1 r How to devel isez size, Price postpaid | | into a trunk, under the bed or anywhere. Lots ® improve your dance stepe ated » of fun fooling teacher, policeman or friends, /S Fie. have te lene: Taieariie Caer wba rt Li Natural and Reverse Turns, the Reverse Wave. Tne Quickstep swaying to muste. Waltz. Back- ward changes, the Continental, The famous Kiss dance, the Man- hattan, the College Rhumba, the Carlo, Charleston, etc. Art of Dancing 25c

g

= ' Complete blueprints for 3 dif. ferent racers. The one illug- trated can be built for a few dollars. All about racey A parts, gears, transmis< sions, dirt track rac- ers, track regula- tlons, blueprints, Plans. ADB A MOTOR TO YOUR BIKE al low cost. increasing speed, ote., etc. Cram- med & jammed full of information

Although this outfit issomarvelously cheap, itis quite efficient. and will take splendid pic- . tiures. Takes pictures 2 fom x1 1% inches, sharp and distinct. Good lens, <4 view findera Simple vet

and instantaneous,

per, printing frame with | written that a child cannot fail to understand. ont 25c. == € Camera and complete outfit for only 35c with COMPLETE BOOK 2 et GORGES stamp. Over 10¢ extra for postage and packing. Extra film Midget Bible Said to bring 10¢ per package of five films, EX rintin 200 pages. Sa ne pane” Loe per packages : wee Rood luck to owner. Price 15c. INSERT A COIN AND OUT COMES A DELICIOUS CHOCOLATE BAR Thrift Bank and Slot Machine The most novel, popular. and useful bank ever invented! A regular slot. machine, savings bank and profit-maker all in one, Just think of having this handy bank around, and as soon as your friends drop in a penny, nickel or dime—out comes a chocolate bar, all) wrapped up! Leave the bank around the house and you will soon: find that It fills up while you're gone. An easy way to save money—and make money! Get Plenty of Chocclates—They’!Il Go Fast! Well "made of sheet metal with a regular locked door so you can open aml remove the money and fill it with chocolate bars. On the front is a slot to drop the coin In, a window showing the chocolate bars, and a regular drawer that opens when each coin is deposited. .Handsomely lithographed in brilliant yellow, green and red. Get two or 25°

three banks and PLENTY of refills—they’ll go fast SWEET THRIFT BANK & SLOT MACHINE. Only Chocolate Bars to fit in the Machine. Package of 10,...10c

developed. DETROIT, MICHIGAN | Maiy pe sown either indoors oF outdoors and blooms the first year pink

Nearly 800 pages of magic, tricks, novelties, | to PRODUCE SPLENDID When Answering Advertisements Please Mention July Modern Mechanix 143 b

Page 144

A. C. GENERATORS CONVERT Dodge 12V Generator to i, H.P., two speed, 32V Motor in ten minutes, no expense. Pumps water, runs saw, grinder, shop tools. Instructions $1.00. Dorris Plant, Moorcroft, Wyoming. PRACTICAL changes for automobile generators. See our advertisement at bottom of page 19. Autopower. ADVERTISING AGENCIES ie a ee ee ay ` ADVERTISE: Get mail-order business, agents. Free assistance. Free Ad- Guide of newspaper, magazine, circula- tions, rates, mailing-lists. Chicago Ad- vertising Agency, 22 West Jackson, Chicago. ADVERTISE: 5 lines in 100 National Mail Order Publications $4.00. Lists Free. Advertising Bureau, 4515-B Cot- tage Grove, Chicago. 33 WORDS, 25 magazines, three months $2.00. Goodall Agency, 742 Market, San Francisco. FREE NEW advertisers rate guide. Brown Advertising Agency, 140 South Dearborn. Chicago. AGENTS WANTED AGENTS: Smash go prices. Santos Coffee 12c lb. 4-0z. Vanilla 8%c. Razor Blades 10 for 8%c. 100 Sticks Chew- ing Gum 12c. Christmas Cards, 21 in box, 14c. 150 other bargains. Premiums. Experience Unnecessary. Carnation Cos MN, St Lonis, Mo, MAN AND WIFE—\to run local Coffee Agency. Earnings up to $240 in a month. New Ford Sedan given you as bonus. I send complete outfit. You don't risk a penny. Details free. Albert Mills, 2348 Monmouth, Cincin- nati, Ohio. MAKE More Money Taking Orders; Shirts, Ties, Hosiery, Raincoats, Uni- forms, Dresses. Sales Kit Free! Ex- perience unnecessary. Nimrod Com- pany, Department 132, 4922-28 Lincoln Avenue, Chicago. PROFIT with sell, repeat. new products. Make, Analysis. Research. Guaranteed formulas. Biggest catalog free. Special prices, leads. Gibson Laboratory, Chemists, CE-1142 Sunny- side, Chicago. BIG Money Applying Gold Initials on Automobiles. Easiest thing today. Free Samples. Also, Sideline Salesmen for Name Plates and Tire Cover Transfers. ooo 1084 Washington, Boston, Tass. GOLD Reflecting Window Sign Let- ters. Penny Each. Large Sizes. Easily Applied. New Styles. Absolutely Beautiful. Free Samples. Atlas Sign Works, 7941-G Halsted, Chicago, Ill. 1000 BARGAINS, Drygoods, Notions, Drug Sundries, Specialties, Novelties. Agents undersell stores. Free catalog. Jobbers, Dept. 1998-A, 930 W. Roose- velt, Chicago. CLEAN-E-ZE Metal and Furniture Polishing Cloth sells on sight, 12x12 sample 20c; small free. Para-Sweet Co., Pleasantville, N. J. YOU’LL Like Resilvering Mirrors. Autoparts, Reflectors, Making Chipped Glass Signs. Write Sprinkle, Plater, 850, Marion, Indiana. Classified Advertisements Rate for classified ads, 18¢ per word (include name, address and alf numbers), per insertion. accompany order and be received in this office June 3rd for the August issue (on sale June 28th), Modern Mechanix Hobbies & Inventions, {501 Broadway, New York City. Erects Miniature Church Local housewives supplied cement and pieces of broken china to make this miniature church at Guernsey, France. Brother Deodat, a priest, who built novel church, makes minor repair. AGENTS’ Gold Sign Letters for store windows. 500% profit. Free sample. Metallic Letter Co., 426 N. Clark, Chicago. HOW to obtain capital, fully explained, particulars free. Star Service, Wapa- koneta, Ohio. Established 1934. OPPORTUNITY Guide (48 pages) and sample novelty, 10c. Hubco, Box 138, Omaha, Neb. EARN $10 quickly. Deliver our cir- culars. Answer. Rush. Rundell A., Coshocton. Ohio, $500 MONTHLY, Manufacture nov- elties. Outfit $1.00. Mango, 496B-S16, Newark, N. J. SELL Novelty fun cards, novelties, etc. Samples, list 10c. National, Box 500H, Cincinnati. ra AMERICAN POLICE JIU JITSU 13 KNOCKOUT Blows without use of fists, by internationally famous _ Jiu Jitsu instructor. Send 15: cents. Se Je Jorgensen, 283 Maritime Building, Seattle, Washington. AUSTRALIAN OPALS AUSTRALIA’S Lovely Opals. Illus- trated Catalogue Free. Good selection $5.00. Seward Optician, Melbourne, Australia. AUTOMOBILES 100 MILES for 30c. Semi-Dieselize your car now for that vacation trip this summer. Our controlled heat system is most efficient and reliable. Copyrighted plans $1.00 postpaid. Crippen-Deming Lab., Norwood Rd., Jackson, Mich. Minimum 10 words. Cash must Address Classified Mgr., AUTO TRAILERS ONE Wheel Trailer. America’s handi- est light, all purpose trailer. Particulars free. Blueprints 50c. Six different house trailer blueprints and drawings, $1.00. Economy Trailer Co., Sedan, Kansas. AVIATION GET INTO AVIATION. Air trans- port pilots get up to $7,000 per year; mechanics, $2,500. Learn at this Gov- ernment approved school. Write for complete information. State age. Lin- coln Flying School, 4002 Aircraft Bldg., Lincoln, Nebr. AEROPLANES, New Production, $98.00. Easy payments. Propellers for aeroplanes, boats, sleds, wind-driven generators, $2.50 up. Send 25c for more information. Universal Aircraft Co., Fort Worth, Texas. BROTHER, Can You Spare a Dime? If you can, send it to me and Pll send you my Low-Priced Aviation Material Catalog. (Canada 20c.) Kari Ort; 646 W. Poplar, York, Pa. INEXPERIENCED workers, apply for aviation jobs now. Full salary while learning. Details for stamp. Airploy- ment, Box 553, West Los Angeles, Cali- ornia. — AMBITIOUS Young Men interested in entering Aviation as Apprentices, see ad on page.134, BLUEPRINTS METAL, TUBE Midget Radio, the last word in compact radio receivers. You can construct this set even though your knowledge of radio is limited by follow- ing the large pictorial blueprints avail- able, from Modern Mechanix Publ. Co., Greenwich, Conn., at 50c postpaid. $700 BUYS all materials for your Send 25c for design folder, details. Dana Co., Box 1381, Indian- apolis, Ind. BOATS BUILD electric outboard motor from auto generator. Operates with car bat- tery—lasts all day. Complete plans 10c. LeJay Manufacturing, 1514 Lake, Minneapolis, Minn. F ORD and Lincoln Marine Conver- sions. Send 10c for information. Lehman Engine Co., Newark, N. J. BOOKS AND PERIODICALS SPORTSMEN’S MANUAL—tThe out- doors man’s guide containing scores of practical articles by America’s leading outdoor writers, covering every phase of fishing, hunting, camping, and trap- ping. This book, edited by Robert Page Lincoln, will make that next vacation a dozen times more enjoyable. Price 50c at your newsstand, or order directly from Modern Mechanix Publishing Co., Fawcett Bldg., Greenwich, Conn, CASH PRIZE contests everyone can enter—interesting stories, articles and features always in every issue of The Little Chronicle, ‘‘America’s fastest growing Magazine’, 10c brings sample copy: Little Chronicle Corp., Oak Park, Accept No Substitutes! Always Insist on the Advertised Brand!

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ue SS a TA — E = -x AT ae "4: SR ee ee SNe ae meee sy BUSINESS OPPORTUNITIES a ee PLASTEX INDUSTRY needs manu- facturers on small scale and for big production of Religious Statuettes, Art Goods and Novelties in Plastex and marble imitation. Cheaply and easily made in our guaranteed rubber moulds. We cooperate in selling goods. You are just in time for big wholesale season now starting. Interesting booklet mailed FREE. Plastex Industries, 1085 Washington Ave., Dept. R, New York. NEW Fascinating Business. Repair, adjust typewriters, adding machines. Learn easily at home from factory ex- pert. Earn up to $15.00 daily. Com- plete instructions covering all makes $3.00 postpaid or sent C.O.D. in United States. Adding Machine Equipment Service, 3601 Michigan, Dept. 204B, Chicago. STOP—Look—Listen, Jet us tell you of 24 Real Ways to Make Money. Selected Opportunities. Be Financially Independent. Particulars 25c coin, postpaid. Write today and receive Free Souvenir from Capital City of W. Va., Rico Service, Dept. K, Box 744, Charleston, W. Va. BUSINESS Opportunities. Start your own business. No experience, little capital required. We furnish formulas and teach Marbleizing cements and porcelain finish. Make your own rubber molds. Dime brings rubber, porcelain, and marble samples. Cowell Institute, Grayling, Michigan. START an exclusive, independent busi- ness of your own in the booming build- ing field. Experience not necessary. Investment one hundred dollars, easy terms. Secured by materials and ex- clusive franchise. Get complete in- formation. P.O. Box 2606, Memphis, Tenn. WE START you in business, furnish- ing Outfits and Instructions, operating “Specialty Candy Factory” home. Men and women, earn $25.00 up to $60.00 weekly, all or spare time. (Our 29th year.) Booklet Free. W. Hillyer Rags- dale, Inc., Drawer 110, East Orange, MAKE artificial marble, glossy tiles, floors, uncanny. Tabletops, plaques, whetstones, novelties. Cement secrets, hard, fireproof, inexpensive. Brilliant tile and liquid rubber samples 3c. John H. Payn, 945 Grande Vista Ave- nue, Los Angeles, Calif. EARN $25.00 Up Weekly! Clipping and preparing newspaper articles for Simple; fascinating; profit- able. Experience unnecessary. Stamp brings details. National Press, 3923 woe Sixth, Division 76, Los Angeles, alif. NEW Brush Plating Outfits for auto parts, reflectors, etc., connect to a bat- tery, no tanks used. Almost as simple as painting. Good income plating and silvering mirrors, low cost. Free proof. Gunmetal Co., Ave. A, Decatur, IIl. PROFIT with new products. Make, sell, repeat. Analysis. Research. Guaranteed formulas. Biggest catalog free. Special prices, leads. Gibson Laboratory, Chemists, CE-1142 Sunny- side, Chicago. WANTED Manutacturers, by old es- tablished firm to cast Ashtrays, 5 and 10c Novelties, etc. See page 28 for our offer. Metal Cast Products Co., 1696 Boston Read. New York City. TIT MADE over $50,000. Started with $1.00. You have the same opportunity. I will show you how it was done. De- tails for stamp. Peris, Dept. Box 53, publishers. East Rochester, N. Y. When Answering Advertisements Please Mention July Modern Mechanix Movies Aid Piano Students Boyd R. Ringo is shown taking motion pictures of one of his piano students at Tulsa University. When pictures are projected, students see what points in technique need improving, REAL money, steady business, manu- facturing modern raised sign letters, Sells 1c and up. J. H. M. Company, 12844 Omaha St., Detroit, Mich. $30 WEEKLY opportunity! Operate new advancing business. Experience unnecessary. Iron-So-Ezee Company, Dept. B, Mt. Washington, Ohio. SUCCEED With Your Products. Make-Sell Them. Formulas. Processes. Accurate analyses. Catalog free. A. Thaxly Co., Washington, D. C. CHIPPED Glass Sign Making; Mirror Resilvering; Metalware Replating; In- teresting; Profitable. Write—Sprinkle, Plater 845, Marion, Indiana. INVENTION Finance Magazine, 80-H Wall Street, New York. Year sub- scription 60c entered upon promise te pay on receipt of first copy. RAISE Giant Mushrooms! We buy! Start cellar, shed. Book, pictures free. United, 3848 Lincoln Ave., Dept. 89, Chicago. AMATEUR Cartoonists, earn up to $35.00 weekly, copying cartoons for ad- vertisers. 3-N Service, Argyle, Wis- consin. DO YOU need more money or a steady income? Investigate! Details 10c. Bison Service, P-MM, Buffalo, Minne- sota. , SELL by Maıl! Books, Novelties! Bar- gains! Big profts! Particulars Free! H. Elfco, 438 North Wells, Chicago. MODERN little business. Weekly in- come. Home spare time. Details. C. Haynes. Cranbrook. B. C.. Canada. AGENTS—To mail our literature. Good profits. Home business. May- wood, 149 Fifth Ave.. New York. HANDY MEN—Earn money home op- erating Community “Fix-It” Shop. Stafford. Makanda, Illinois. HOW to build and finance for profit— without capital; stamp for reply. Her- hert Seymour, Easton, Md. WHERE to buy at lowest wholesale prices. Information free. Yorena, Box A-312, Bayonne, N. J. >» START Mailorder! Home Businesses! Steady Income. Write. Service Mails, Grand Marais, Mich. OPPORTUNITIES everywhere. Book- let free. Goodall, 60 Lochalsh Road, Inverness, Scotland. AMAZING new money making plans. Get details quick! A. Murray, White- water, Wisconsin. YOUR Own Business Easily Started. Write! Joray, 2136 Park Ave., Phila- delphia, Pa. CAMERAS AND PHOTO SUPPLIES CAMERAS and supplies. Free illus- trated catalog listing everything photo- graphic—still and movie cameras, films, lenses—at tremendous savings. Hun- dreds of bargains, new and used. All guaranteed. We take your old camera or equipment in trade. Write now for your Free copy of our newest money- saving Bargain Book—/just out! Limited edition. Hurry! Central Camera Co. (Photographic Head- quarters since 1899), 230 So. Wabash, Dept. B-205, Chicago. MAKE MONEY in photography. Learn quickly at home. Spare or full time. Previous experience un- Common school education sufficient. Interesting booklet and re- quirements free. American School of Photography, 3601 Michigan Avenue, Dept. 2048, Chicago. PHOTOMURALS—Gigantic ments easily and economically made. omplete illustrated instructions $1.00. Details free. Fogerty, 1689 Capitol, Bridgeport, Conn. OWN acamera? Then read the Photo- graphic Digest. Everywhere 25c. Send 10c for sample to 1666 Linden Street, Brooklyn, New York. CAPITAL Q RAISE NEEDED Business Capital. We show you how. Write fully. En- terprise Bureau, Syracuse, N. Y. CARTOONING CARTOONING, Sketching, etc., by Alexander Murray. 46 lessons, 600 illustrations, including practice sheets, pens, pencils, drawings criticized, $1.00 complete. Singer Art Service, 1782 E. 100th, Cleveland, Ohio. CARTOONING & COMMERCIAL ART AMATEUR Cartoonists—Win $25.00. No drawing ability necessary to win. 26 prizes in all. Rush name on post- card for valuable tips on “How to Make Money With ae Cartoons”, Cash Prize Entry Blank and Rules. Send no money. Cartoonists’ Exchange, Dept. C-357-A, Pleasant Hill, Ohio. CHALK TALKS LAUGH Producing Program, $1.00. Catalog 10c. Balda Art Service, Dept. 65, Oshkosh, Wis. CHARTERS DELAWARE Charters: Complete in- corporating and organizing service $35. Submitted forms. Chas. G. Guyer, Inc., Wilmington, Delaware. DETECTIVES DETECTIVES: Make Secret Investi- gations. Experience unnecessary. De- tective Particulars free. Write, George Wagner, 2640-V Broadway, N. Y. BE A DETECTIVE. Make secret in- vestigations. Excellent opportunity. Write for free particulars. Raymond Stults, Elkhart, Ind. 145 Po fi , a 4 i r sit = cates = £ > ~ =~ = oT. ‘ Ly — LL ss A i ee” y~ pried bel ioe n at v iz | eedt a ed Rs ad ig Eh = a a peta A ol ool coe ¥

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LENE = a 4 a a. a, ae eo 0 DUPLICATORS INCREASE Business Now. ‘‘Excello- graph’? Rotary Stencil Printer reprints thousands everything you typewrite, handwrite, draw or trace. Colors. $19.75 to $44.00. Terms. Illustrated Literature Free to Business or Profes- sional Men. Pittsburgh Typewriter Supply, Department K-4, Pittsburgh, Pa, EDUCATIONAL & INSTRUCTION AMBITIOUS young men trained, for Air Conditioning and Refrigeration jobs, in our Service Department Shops. Practical Experience under our engi- neers. Write Training Division M, Western Trades Association, 2024 W. 6th, Los Angeles, Calif. MEN Wanted—Learn Tool & Die Making. Automatic Screw Mach. Machinist Trade. Big Demand. Actual Experience. Expert Supervision. Write for Free Book “M”. Allied Screw Machine Co., Inc., School Div., 603-9 Lake St., Chicago. WORK FOR “UNCLE SAM.” Start $105-$175 month. Qualify now for next entrance test. Write, Instfuction Ser- vice, 234, St. Louis, Mo. FOREST Jobs available $125-$175 month. Cabin, hunt, trap, patrol. Qualify immediately. Write Rayson Service, B-32, Denver, Colo. IF YOU'D LIKE a Profitable Busi- ness-Profession, learn the Collection Business. Write Cole Associates, Syra- cuse, New York. GET Yourself a Government Job. $105- $175 month. List positions—particulars free. Franklin Institute, Dept. E62, Rochester, N. Y. ELECTRICAL SUPPLIES HUNDREDS of new and rare items, replacement parts and supplies. Send 10¢ for new, 60-page, wholesale cata- log. Autopower, 412-O S. Hoyne Ave- nue, Chicago. ENGINES, MOTORS, ETC. “PRINCIPLES of Semi-Diesel.”? Baok- let illustrating eight practical methods of converting gasoline motors to burn diesel oil, kerosene, or stove distillate. Water injection, causes and remedies for dilution, ‘“‘ping,” etc. Johnston Diesel, Redondo, Calif. Price $1.00. WINDING Data, 225 motors, single and three phase. Price $1.00. Motor Data Service, Box 7631, Kansas City, To. FOR INVENTORS PATENT YOUR IDEA. Write im- mediately for two free books, ‘‘Patent Protection” and “When and How to Sell an Invention.” Fully explain many interesting points to inventors and illustrate important mechanical prin- ciples. With books we also send “Evi- dence of Invention” form. Prompt service, reasonable fees, thirty-seven years’ experience. Avoid risk of de- lay. Address: Victor J. Evans & Co., Registered Patent Attorneys, 921-H Victor Building, Washington, D. C. INVENTORS—Small ideas may have large commercial possibilities. Write us for FREE book, “Patent Guide for the Inventor” and “Record of Invention” form. Delays are dangerous in patent matters. Free information on how to proceed. Clarence A. O’Brien and Hyman Berman, 28-F Adams Building, Washington, D. C. YOUR PENDING PATENTS and new unpatented ideas listed free as news items for manufacturers in our semi- -monthly magazine. Send descrip- tions. “Successful Inventions”, Dept. S5, Barrister Bldg., Washington, D. C. 146 Electrice Scroll Saw Designed for Cutting Metal Plate Metal plate can be cut into any shape with this recently invented cutting and filing machine. The machine cuts metal in the same manner as a jig-saw cuts wood. The saw is fitted with a short vertical movement blade that is started by placing it in a hole previ- ously drilled in the work, after which it is guided over the metal by the operator. WE SUCCESSFULLY SELL inven- tions, patented and unpatented. Write for proof, and tell us what you have for sale. Chartered Institute of American Inventors, Dept. 5-B, Washington, D.C. INVENTORS: Send for my free 72- page book, Conscientious, prompt per- sonal. service on all patent mapen Registered Patent Attorney. L. Randolph, Dept. 341, Washington, D. Č INVENTORS—Why not profit from your UNPATEN TED and PAT- ENTED INVENTIONS? Interna- tional Inventors Service, Leon Building, 501 F. Street, Washington, D. C. “TOW To Sell an Invention.” Booklet of practical information, compiled by Registered Patent Attorney. Posipaid, $1. C. L. Drew, 582 Market St., San Francisco, California. INVENTORS: Protect your inven- tion before spending money for patent. Full information free. Federal In- yentor’s Protective Bureau, Box 1794-F, Milwaukee, Wis. INVENTORS—Low Cost Protection Service. 5748 N. 38th St., Milwaukee, Wisconsin. FORMULAS FORMULAS—AII kinds. Catalog Free. Kemico, 67, Tllinois. FORMULAS, PLANS, ETC. ANALYSIS. Research. Newest guar- anteed formulas. Biggest catalog free. Special prices, leads. Gibson Labora- tory, Chemists, CE-1142 Sunnyside, Chicago. SUCCEED With Your Products. Make-Sell Them. Formulas. Processes. Accurate analyses. Catalog free. A. Thaxlv Co., Washington, D. C. Guaranteed, Parkridge, POWERFUL are furnace melts iron. Plans, casting instructions, $1.00. Billington, General, Gloversville, N. Y. 100 LATEST Formulas, 50c. Satisfac- tion Guaranteed. Literature Free. Pelishek’s, Adell, Wisconsin. ICELESS Ice! Colder! Cleaner! Cheaper! Instructions, 25c. Duffy- Co., Covington, Ky. FORMULAS—Latest money makers. Literature free. D-Belfort, 4042 N. Keeler, Chicago. 550 MONEYMAKING Formulas, 20c. me Book Shop, 100, Park Ridge, llinois. TESTED Formulas; Analysis. Details. Kaplan, 13 S. Eden, Balti- more, FROG RAISING “RAISE Giant Frogs!” We Buy! Unusual offer to beginners. Free Book. American Frog Canning (142-M), New Orleans, Louisiana. HELP WANTED—INSTRUCTION BECOME Business Detective. Earn $1.00 hourly, upwards—spare_ time. Experience unnecessary; we teach you. Details Free. Business Detective Sys- tem, 1009 Oak, Elmira, N. Y. HYPNOTISM HYPNOTISM. Complete 20 Method Course 25c. Lonk Institute Hypnotism, D-1313, Palatine, Ilinois. PSYCHO-THERAPEUTICS Learn How. Rokos, 1728% West Gage Ave- nue, Los Angeles, California. INVENTIONS HAVE YOU a sound, practical inven- tion for sale, patented or u patented. If so, write Chartered Institute of American Inventors, Dept. 5-A, Wash- ington, D INVENTIONS WANTED SMALL inventions wanted by manu- facturers. Jl help you sell your in- vention. S. Hull, L-7829 Euclid Ave- nue, Cleyeland, Ohio. INVENTION S—Patented, Unpatented. Bought outright, royalty. Write Arel- lano-Power Company, 53 West. Jackson, Chicago, Illinois. INVENTIONS Commercialized. Pat- ented or tnpatented. Write Adam Fisher Company, 582 Enright, St. Louis, Mo. LAMP INSECT KILLER STANDARD Electric Lamp kills in- sects indoors, outdoors. $2.00 up. Literature free. Sauer Brothers, Oak- land, Calf. MAGIC TRICKS & NOVELTIES AMAZE and Mystify! Tricks for Home or Stage require no skill. You can perform them—be popular entertainer. Learn fifty good ones by sending 10¢ for “50 Magic Mysteries”, and. receive Free *‘Book of 1,000 Wonders’’, America’s most complete Catalog of low-priced Magic. Lyle Douglas, Station A-3, Dallas, Texas. BE A MAGICIAN. Pleasure or Profit. Book containing 600 tricks, jokes, puzzles, 10c coin. Magicians Guild, Suite 514-M, 56 West Washington, Chicago. LEARN MAGIC — Large Illustrated Catalog of tricks. You Can Do. 250, Holden, 222 West 42nd St., New York. TEN LATEST Tricks, 50c. Bulletins, 10c. Murza, Box 667, Butte, Mont. Accept No Substitutes! Always Insist on the Advertised Brand!

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Ne * workshop plans. MALE HELP—AGENTS $6.85 HOURLY!—Amazing No-Flatz fixes punctures without patching; makes tires puncture-proof! Instantly, perma- nently seals holes made by nails, etc. Big seller. Free sample offer. No-Flatz, Dept. T-164, Cincinnati, Ohio. MALE HELP WANTED LOCAL Agents Wanted to wear and demonstrate Free Suits to friends. No canvassing. Up to $12 in a day easy. Experience unnecessary. Valuable demonstrating equipment, actual samples Free. rogress ‘Tailoring, Dept. U-219, 500 Throop, Chicago. MALE—INSTRUCTION DETECTIVES. Work home or travel. Experience unnecessary. Write, Ameri- can Detective Institute, 2640-T Broad- way, N. Y. MANUFACTURER WANTED BLOTTING Attachment for Fountain Pens. Just patented. Write for patent copy. Atwood R. Knorr, Berwick, Pa. MIDGET AUTOMOBILES BUILD a Midget Miller Racer. Com- plete plans for constructing this authen- tic midget automobile appear in the new 1936 edition of How-To-Build-It along with many other interesting home and Send 50c for this 148- page hook to Modern Mechanix Publ. Co., Greenwich, Conn. USED Motors! For sport midgets, (Maytags, B & S, Smiths, small Har- leys, Indians, etc.)—$4.00 up. For racers, (Hendersons, Indians. Harleys, Saxons, Specials, ete.)—$10.00 up. List of 65, with illustrated motor in- formation, 20c. Shipps Midgets, Box 543-B, Zanesville, Ohio. S elena MISCELLANEOUS POPCORN, cheese coated, Carmelcrisp, Crispette, Potato Chip, Salted Nut Machines. Long-Eakins Co., 1974 High St., Springfield, Ohio. MEN—Do you want a Packard Lektro Shaver without cost? Inclose 10c for particulars to Packard Novelty Com- pany, Kalispell, Montana. BURIED TREASURE Minerals, free booklet, photographs. Fisher, Palmer Bldg.,. Hollywood. ieee ŘŘŘŮĖ a MODEL RAILROADING BUILD a Model Railroad in 00 gauge (34 inch between rails). A complcte catalogue of parts, construction kits, and completed units, One Dime. Nason Railways, P. O. Box 9, Mt. Vernon, N. Ya Dept XA 00 GAUGE locomotive ‘Commodore Vanderbild” 854 inches long (54 inch between rails) 20 volt, ready to run, $5.50 postpaid. Catalog 10c coin. Johansen, Kattesundet 14, Copenhagen, Denmark. MODELS & MODEL SUPPLIES YOUR Ideas developed into practical working model. 30 years successful experience; thousands satisfied custom- ers. Confidential service guaranteed. Bank references. Send 3c postage for 32 page book ‘‘Making Inventions Pay.” Crescent Tool Company, Dept. T. Cin- cinnati, Ohio. FULLY Illustrated Circular. Listing 40 engines. Locomotive castings. Sup- plies. Stamp required. Emco, 2417 N. Ashland, Chicago. BIG 96-Page Model Engine Catalog, postpaid 20c. Particulars FREE. Evraymesco, 28 N, Clinton, Chicago. When Answering Advertisements Please Mention July Modern Mechanir Farmers Wear Mud “Skis” This woman is demonstrating the effec- tiveness of the mud “skis” that are worn by farm workers in Gloucester, England. Without the novel skis, the workers would become mired. Machines, SENSATIONAL, bargains. Machine, tools, ete. Lists. Howard J-2417 N. Ashland, Chicago. MONEY MAKING OPPORTUNITIES AMATEUR Cartoonists—Win $25.00. No drawing ability necessary to win. 26 prizes in all. Rush name on post- card for valuable tips on “How to Make Money With Simple Cartoons,” Cash Prize Entry Blank and Rules. Send no money. Cartoonists? Exchange, Dept. C-357-B, Pleasant Hill, Ohio. MOTION PICTURE & SOUND EQUIPMENT LEARN Motion Picture Theatre Busi- ness. Home-Study Training: Manage- ment, Advertising, Projection. Free Catalog. Theatre Institute, 345 Wash- ington, Elmira, N. Y. HOME Movies cheaper than Snapshots. Guaranteed 8mm Camera $9.95 prepaid, Film—60c 30-ft. Reminder Sales Co., Cudahy, Wisc. MOTION PICTURE & SOUND EQUIPMENT FOR SALE DEVRY Soundfilm 35 projector, am- plifier, speaker complete $189.50, 35mm shorts $1.00, 16mm Silent films 100’ 400’ $2.85. Sound, odd, 400’ $6 collapsible screen 22”x30” spring roller, map case, adjustable tri- pod $4.50, Leica Camera F3.5 perfect $45. RCA Soundfilm 16mm projector 1,600’ capacity with amplifier, speaker, complete $198. Victor soundfilm, com- plete outfit $159.50. Victor sound 16mm projector complete with amplifier $79.50. 8mm Camera $9.95, Motor Projector $14.95. Coronation Movies: 8mm, 50’—$1.55, 100’—$2.84, 180’— $5.50. 16mm, 100’—$2.00, 200’—$4.00, 360’—$7.20. Soundfilm: 200’—$7.00, 350” DeLuxe Edition $11.95; 8mm, 914°, 16’, 35 silent, soundisc, soundfilm. America’s largest film library. Rentals sent anywhere. New Bargaingram; new, used equipment. Trades accepted, bought, Mogull’s, 1944-M Boston Road, New York. EE n MOTORCYCLES RECONDITIONED Motorcycles. New —used parts for all makes. Authorized Harley-Davidson Dealer. Whitman Motorcycle & Supply Co., 405-9 South- west Blvd., Kansas City, Mo. MUSIC & MUSICAL INSTRUMENTS PIANO By Ear. Free explanatory booklet; no obligation. Day-V-Way, 730 Woolworth Building, Dearborn, Michigan. OFFICE EQUIPMENT TYPEWRITERS, multigraphs. address. ing machines, adders, dictaphones, dup- licators. sealers, folders. Save half, write Pruitt, 553 Pruitt Bldg., Chicago. SS a a e OLD MONEY WANTED $2000.00 for ic. We Guarantee To Pay World’s Highest Prices, certain 1909 cents $25.00, 1860 cents $500.00, Large cents $2000.00, Quarters $300.00, Gold Coins $7500.00, 1913 Liberty Head Nickel $350.00, certain 50c of 183S8— $1500.00, 1853—$750.00, 1915—$13.50, 1921-—$26.00, 1922—$60.00, 1928— $12.00, 1935—$60.00, Half Cents, Half Dimes, Foreign Coins, Paper Money, - and thousands of others up to $5000.00 each. Know What Your Coins Are Worth. Send Dime for 1937 World's Largest 10c Complete Illustrated Cata- logue. Romanocoinshop, Dept. 159, Nantasket, Mass. $5.00 to $500.00 EACH paid for Old Coins. Keep all old money. Get posted. Send 10 cents for Illustrated Coin Value Book, 4x6. Guaranteed Buying and Selling Prices, Coin Exchange, Box 18, Le Rov, N. Y. PATENT ATTORNEYS PATENT YOUR IDEA. Write imme- diately for two free books, “Patent Pro- tection” and “When and How to Sell an Invention.” Fully explain many in- teresting points to inventors and illus- trate important mechanical principles. With books we also send “Evidence of Invention” form. Prompt service, reasonable fees, thirty-seven years’ ex- perience, Avoid risk of delay. Address Victor J. Evans & Co., Registered Patent Attorneys, 920-H, Victor Build- ing, Washington, D. C. E ES cman ee ean INVENTORS—Small ideas may have large commercial possibilities. Write us for FREE Dook, “Patent Guide for the Inventor’? and “Record of Inventicn’’ form. Delays are dangerous in patent matters. Free information on how to proceed. Clarence A. O’Brien and Hyman Berman, 28-F Adams Building, Washington, D. C. oe ae OE] “INVENTOR’S Guidebook” containing 96 mechanical movements and advice about patenting, selling inventions, also “Record of Invention”, Free. Frank A, Ledermann, Patent Attorney-Engineer, 154 Nassau Street, New York. PATENTS INVENTORS—Small ideas may have large commercial possibilities. Write us for EREE book, “Patent Guide for the Inventor” and “Record of Invention” form. Delays are dangerous in patent matters. Free information on how to proceed. Clarence A. O’Brien and Hyman Berman, 28-F Adams Building, Washington, D. C. PATENTS. Booklet free. Highest references. Best results. Reasonable fees. Watson FE. Coleman, Victor Build- ing, Washington, D. C. INVENTIONS Wanted—Patented, un- patented. If you have an idea for sale, write Hartley’s Inc., Box 928-J, Ban- gor, Maine. PATENTS WANTED INVENTIONS Commercialized. ented or unpatented. Write Adam Fisher Company, 582 Enright, St. Louis, Mo. 147

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nu Clear Plastic Has Quartz Light Characteristics John Borchester of the du Pont Com- pany is shown at his lathe on which *‘Pontalite,”’ a new crystal clear plastic, is being machined. Resembling quartz, it transmits light around a bend. PERSONAL Dooe Se ee rs DEVELOP personality, charm, sex ap- peal. Overcome bashfulness. Attain power, sticcess. Free booklet “Power of Personality.” No obligation. School of Personal Development, D3 Wool- worth Bldg., Dearborn, Michigan. HAIR getting thin? Then investigate my “No Hair—No Pay” offer. No obli- gation. Paul Downing, 626 Swetland Bldg., Portland, Oregon. STUTTERING and Stammering cor- rected at home. Booklet free. Paul J. Wolfe, Box 52, Pittsburgh, Penna. E OD PHOTO DEVELOPING a eee DEVELOP and print your own pic- tures. Save time, money with our com- plete $1.49 outfit postpaid or pay post man $1.55 COD. Includes electric ruby lamp, printing frame, photo paper, chemicals and equipment. One of hun- dreds of amazing bargains in our Free, newest, money-saving Bargain Book. Send for it today! Central Camera Co., 230 So. Wabash, Dept. B-255, Chicago. FINER Finishing. Rolls developed and printed, with One Colored enlargement, or two professional enlargements. All for 25c (coin). Genuine, Nationally Known, Moentone Superior Quality. Moen Photo Service, La Crosse, Wis. AT LAST! All your prints in natural color. Their lifelikeness is outstanding; their beauty amazing. Roll developed, 8 natural color prints, 25c. Fast service. oo Color Photo, C-39, Janesville, Vis. $100.00 VALUE prize offer. Roll de- veloped, 8 guaranteed prints, oil painted enlargement, coupon on 8x10 painted enlargement, 25c. Immediate service. Janesville Film, A-39, Janesville, Wis. WIN prize, $100.00 value offer. Roll developed, 8 guaranteed prints, 2 en- largements, coupon on 8x10 painted enlargement, 25c. Daily service. Mid- west Photo, B-39, Janesville, Wis. WESE AE) _ a N ROLLS DEVELOPED—Two Beauti- ful Double Weight Professional En- largements, 8 Never Fade Prints, 25c. Century Photo Service, LaCrosse, Wis. 148 ROLLS DEVELOPED—25c coin. Two 5x7 Double Weight Professional Enlargements, 8 gloss prints, Club Photo Service, LaCrosse, Wis. LARJARGRAPH Reprints: Five (5x7 enlargements) 25c. Cardinal Photo, Summit, N. J. PRINTING PRINT your own cards, stationery, circulars, advertising, etc. Save money. Easy rules furnished. Print for others, big profits. Junior press, $5.90; job presses, $11; power, $149. Write for details. Kelsey Co., $-57, Meriden, Conn. 2,000 Business Cards Neatly Printed $1.50. Quick Service. Free Samples. Atlas Distributing Co., 1814 Bedford Ave., Pittsburgh, Pa. 100 EACH, 8%x11 Letter-Heads, 634 Envelopes, $1.00 Postpaid. Samples! Parker Co., MM, Box 63, Indianapolis, nd. 250 ENVELOPES, 85 cents post paid. K. Moore, 6538 Coleman, Dearborn, Michigan. 1500 NEAT Business Cards $1.00. World, 2710-G Clara, St. Louis, Mo. ee PROPELLERS AIRPLANE Fan Propellers. 20”, 22”, 24" $2.00 each. Fanco, 7716 So. Broadway, St. Louis, Mo. RADIO 2 a ee rr BLUEPRINT, distance record crystal set, 17 others, with **Radiobuilder”’ year—25c. Laboratories, 151-K Liberty, San Francisco. RADIO & TELEGRAPHY RADIO BUILDERS’ MANUAI—A book of radio set building plans and kinks for the home experimenter. Everything from a crystal set to a powerful 6-tube auto radio is included. Price 50 cents—order directly from Modern Mechanix Publishing Co., Fawcett Bldg., Greenwich, Conn. RADIO Engineering, broadcasting, aviation and police radio, Servicing, Marine and Morse Telegraphy taught thoroughly. All expenses low. Catalog free. Dodge’s Institute, King St., Val- paraiso, Ind. ne RAZOR BLADE KNIFE ARTISTIC. Durable steel. Watch chain loop. 2%”x1"x%”, folded. 25c, coin. Vital Products-M, Hoboken, N. J. SALESMEN WANTED Dee BIG Earning Opportunities For You. Own good paying business of your own Free. Everything needed for you to start at once is supplied without cost. Hundreds of different direct selling op- portunities listed for your selection. Nothing like this directory anywhere. Send 25c for big 160 page book that puts you in touch with the greatest money-making opportunities in every section of the country. Write Direct Selling Institute, Inc., 75 East Wacker Drive, Dept. C, Chicago, Ill. WANTED—Men for good paying work with a large shoe company. Good pay every day. Free shoes as bonuses to “so-getters”. No experience needed. Complete sales outfit sent free. Write Consolidated Shoe System, Dept. G28, Chippewa Falls, Wis. GOLD Reflecting Window Sign Let- ters. Penny Each. Large Sizes. Easily Applied. New Styles. Absolutely Beautiful. Free Samples. Atlas Sign Works, 7941-G Halsted, Chicago, Il. Smokestacks Pierce ~ Cliffs Presenting a weird appearance, these smokestacks run along the top of cliffs near Folkestone, England. They con- nect to tunnels through which trains pass through the cliffs. mio Se SELL Celluloid and Cardboard Pricing Tickets, Steel Shelf Moulding, Change- able Signs, Menu Covers. Every Store Prospect. T. Pricing Press, 124 White St., New York. SALESMEN. Jobbers. Sell Hayana Cigars to Consumers or Dealers. Com- mission. Wholesale. Sullivan Cigar Co., Tampa, Fla. en en ain an a TATTOOING SUPPLIES e o e one cee TATTOOING Outfits, Supplies—Cata- logue. Guaranteed Remover. “Waters,” M-965 Putnam, Detroit. n TELESCOPES, MICROSCOPES, ETC. TELESCOPES, Microscopes, Binocu- lars. Lowest prices. Optical catalog free, Brownscope Company, 234 Fifth Avenue, New York. TELESCOPES, Microscopes, Binocu- lars, Chemistry, Mineralogy. Catalog Free. Teeko, 315-K, Evanston, Illinois. BUILD Reflecting telescopes; catalog free. Instructions 10c. Optical Labe- ratories, Larchmont, N s FREE Literature. Telescope Makers Supply Co., Box 213, Flushing, N. Y; pE WELDING o a — DODGE Arc-Welder 25-200 amperes. Build it yourself. Low cost and up- keep. Results guaranteed. Certified Instructive Plans $1.00. C.O.D. $1.12. Welders’ Club of America, Box 3432-B, Merchandise Mart, Chicago. ARC WELDING OUTFIT, Heavy Duty, $2.00. Weld Fenders, braze, solder. Lavrow, 4368-W, Warren, Detroit. Stamp appreciated. WIND ELECTRIC PLANTS BUILD wind light plant from auto- mobile generator. Complete plans and catalog 10c. 50 other generator changes. LeJay Manufacturing, 1614. Lake, Minneapolis, Minn. WIND Driven Generators, Propellers, lowest prices. Literature 3c. Wood- craft Propellers, Hillside Station, Wichita, Kansas GENERATOR Propellers, expertly de- signed at factory prices. niversal Aircraft Co., Fort Worth, Texas. WOOD CARVING “MODERN Wood Sculpture,” com- plete instruction book on carving statues $1.00. Lee, Wood Art Studio, Dept. 3, Centerville, Ia. Accept No Substitutes? Always Insist on the Advertised Brand! T A, TAA H= aa wl eae Calis sale ce a = "ek teh ples ih PTA E= n m r a NT bee ae aont a a aaa aa se al Be eni dn Pye Rage ee

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Exposing Counterfeiters [Continued from page 120] ` is to note carefully the exact structure of the corner ornaments. There are numerous slight distinctions between the real and the false which the eye can be trained to detect very quickly. At first thought the repairing of stamps might not be regarded as a crooked procedure. Never- theless it is being done on a large scale, and with a deliberate intent to deceive, particularly in Europe, Mr. L. Stewart Barr says. In France such sharpers are especially clever and in Austria there are at least 20 specialists who do nothing but “fix up” stamps. Mr. Barr explains: “As is well known, certain rare stamps in per= fect condition will command enormous prices. But if they happen to have a slight tear or thin spot their worth will skid down to perhaps one-tenth of the catalogue value. No wonder, then, that the best of the repair crooks do a flourishing business. They maintain a regular working arrangement with shyster dealers,

“In every sense of the term the repair charla- tans are real artists. They know the composition of paper to a precise degree. In the case of a job where a hole or thin spot is to be disguised they are able to add a tiny bit of paper in such fashion that the unaided eye finds it next to impossible to detect the fraud. A true stamp connoisseur, however, can locate the deception immediately by simply dipping the suspected stamp in benzine, whereupon in most cases the added portion will stand out in sharp delinea- tion from the main body of the stamp. “Similar results may be achieved by carefully examining the stamp under a fine quartz lens, In such case the observer should experience no trouble in distinguishing the tiny outline of the foreign paper added during the repair process.” Despite all the philatelic fakes now on the American collector’s market, Messrs. Robinette and Barr conclude: “To combat successfully most of the illicit maneuvers of the stamp racketeers, the average collector needs a sincere love of collecting, an alert eye and a willingness to work hard at his chosen hobby,” ADLETS FOR HOBBYISTS (See regular classified section for rates and other information.) STAMPS

SUPER-WONDER Packet offered, containing 60 different stamps from Afghanistan, Transjordania, North Borneo, Manchukuo, Sudan, Macao, Iraq, Charkhari, French and British Colonies, including natives, beasts, ships, etc., all for 5c to approval applicants. Big illustrated lists included. Kent Stamp Company, Box 87-Z (G. P. O.), Brooklyn, N. Y. el np Ee iw GIANT Netherlands Commemorative Triangle, Jubilee, Air- mails, Pictorials in Mammouth Collection—10c, with Double Premium Approvals, Free Airmail Collection given regular customers. Tru-Value Stamp Service, Box M1412, Hart- ford, Connecticut.

MAGNIFICENT Mourning Stamp; complete issue com- memorating bloodiest period in history with 20 additional commemoratives only 10c. Friendly Filatelists, 3615 N. Sydenham, Philadelphia, Penna, ee ee S a a ee EXTRAORDINARY Free Offer—Turks Caicos,-$5 U. S, Caymans, Western Samoa (native girl) genuine Baden. Everything free to approval applicants enclosing 3c postage. Niking Stamp Company, 1-MM Hanson Place, Brooklyn, pre ane N LOLO T PRODIGIOUS Gift! Scare Perak, Negri Sembilan, Bi- colored Airpost, Picturesque Trinidad, Siberia, Selangor, etc. —Free with Approvals! Postage 3e. Saxon Company, Albee Bldg., Brooklyn, N. Y a ee ei L UNITED STATES—-75 different 30c; 125 different ar- ranged on card, each with catalog number $1.00; 25 different free to foreign approval applicants, enclosing 3c. Sidenburg, Baroda, Mich. rr a a aa a STAMPS! 100 diff. 3c; 500 diff. 35c: 1,000 diff. 90c! Illustrated Album (4000 spaces) 22c. Approvals sent. Tatham Stamp Co. (D9) Springfield, Mass. ee ABSOLUTELY Free! Valuable packet to approval appli- cants. Don’t send postage. Cousens Stamp Co., P.O. Box 2626SS, Youngstown, O. ——— a a d a MONTHLY Stamp Magazine, 6 months and 25 foreign stamps, 25c. American Stamp Journal, Cedar Rapids, Iowa. When Answering Advertisements Please Mention July Modern Mechanix = P - - ' : i m = = ar y ze x Z E } - z z = Š wis =- l > ' sW Ue ane aN a n aa H a n FREE!!! New King George VI set. ROBERTS, 901T Fourth, Baycity, Michigan. Weismann, 202 Postage 3c. PENNY Stamp approvals sent on request. Brook Ave., New York. sae neni a a oe 5000 DIFFERENT stamps, mounted, $16.50. Meade Bros., Kansas City, Mo. : a ag) ieee ee COINS $5.00 TO $500.00 EACH paid for Old Coins. money. Get posted. Send 10 cents for Illustrated Coin Value Book, 4x6. Guaranteed Buying and Selling Prices. Coin Exchange, Box 17, Le Roy, N. Y. CALIFORNIA GOLD, quarter size, 27c; $1 size, 53c. Illustrated Catalogue Coins and Stamps 25c. Norman Shultz, Salt Lake, Utah. a ee ee ee FREE: Foreign Coin, Banknote and Large Illustrated coin catalogue, for 4c postage. Approvals sent. Tatham Coinco, Springfield-9, Mass. a ee COINS, Beadwork, Indian Relics, Minerals, Books, Curios, a Catalogue, 5c. Indian Museum, Northbranch, ansas. Sen ee eee COLLECT Tax Tokens: 7 different, all metal, 20c. Wayne Ward, 327 Fast Second, Moscow, Idaho. [INDIAN CURIOS Keep all old SS E U INDIAN CURIOS. 100 good ancient Arrowheads $3.00. Tomahawk Head 50c. Dardanelle, Arkansas. INDIAN RELICS a pe ee L U T 12 ARROWHEAD, Spearhead, Wampum, Gempoint 99c— 120,000 Bargains, Photolist 10c. Museum, Rutland, Illinois. Illustrated catalog 5c. H. Daniel,

ANTIQUE FIREARMS BLUNDERBUSSES, Matchlocks, Flintlocks, Duelling Pistols, 87 Bargains. Photolist 10c. Museum, Rutland, Illinois. 149 a alba = afi =" Ae EET" A a A x . <m SA. eee

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INVENTORS Pages 6 and / SPORTSMEN’S MANUAL Packed with articles that make hunting, fishing, and camping trips more enjoyable and successful. 148 pages. 200 pictures PRICE 50c At your newsstand, or order from MODERN MECHANIX PUBLISHING CO. Fawcett Bidg. Greenwich, Conn. Concentrate your talents on inventions that will pay BIG MONEY. 1936 Edition of 1500 NEEDED INVENTIONS by R. F. Yates tells what inven- tions manufacturers NEED badly. Describes in detail 1500 Needed Inventions in these fields: General Problems; Automotive; Electrical; Me- chanical; Chemical; Aviation; Radio; Marine. Also chapters on the Ten Most Needed Inventions, and on new scien- tific discoveries important to inventors. Simple, practical ideas—one idea from this book may win you a fortune. If you want to invent. know what inventions will pay you the most money. This book tells you. Keeps you from working on inventions nobody wants to buy. Large cloth bound book, 250 pages, nine big chapters. Only $2.50. Drop a postal and we will send 1500 NEEDED INVENTIONS C.O.D. We pay postage if you send cash with order. If not delighted after 5S days’ examination, return it and get your money back. INVENTORS’ SELLING GUIDE How and where to sell patented or unpatented inven- tions. inventors’ Selling Guide by R. - Yates, noted authority on inventions, gives classified list of nearly 1000 manufacturers who buy ideas. Tells how to sell unpatented inventions safely, how to sell chain stores, how to price inventions, selling by correspondence and demonstration, how to find buy- ers, ete. Tells what an inventor must know about Law, Royalty, Contracts, Patents Pending, Financing, Gyp Schemes, Selling Methods. Cloth bound book, 224 pages, 15 chapters, postpaid $2 (or C.O.D. plus postage.) Satisfaction guaranteed. BOTH BOOKS FOR $4.00 if ordered at one time Write for FREE specimen pages and complete catalog of valuable books for inventors. DONLEY PUBL. CO., 509 Fifth Av. Dept. M-7, New York, N.Y- Also: Take Out Your Own Patents, $1.00 Making Unpat- ented Inventions Pay, 50c 150 Accept No Substitutes! He Beat Oyster At Its Game [Continued from page 142] The solution of the problem was worked out long before Pfeiffer’s time, but it remained for him to mechanize the bead-making art. The glass bead is simply built around the hole. A metal wire is used as a core or support for the bead maker to turn a bit of soft molten glass into a perfect globe simply by the whirling action. When the glass has cooled and set, the whole business is thrown into hot nitric acid and the wire dissolved out. Since glass is impervious to acid, the wire disappears and the hole remains. And so you have the secret of those clean-cut holes in all glass beads. Lightning With Oudin Coil [Continued from page 137] the secondary coil with a flat spiral of copper or brass ribbon about the base to act as the primary. Because it deals with high frequency electricity, no metal core is necessary. The cylinder for the secondary is 53 inches high and 15 inches in diameter. It is constructed without the use of nails throughout for nails will cause consider- able loss in current due to brush leakage. The cylinder is formed on three plywood discs 14% inches in diameter from mounting board or strips of wood “%-inch wide, 14-inch thick and 53 inches long. ‘The strips are placed side by side and as close together as possible. When the entire circumference has been covered you should have a solid, well constructed, wooden cylinder. It should now be shel- lacked and covered with a layer of wrapping paper. This serves to remove the rough edges left by the strips. The winding on the secondary consists of 700 turns of No. 22 D. C. C. copper magnet wire, with the turns spaced 14 to the inch. This will amount to about 2,670 feet or 5.2 pounds of wire. To wind the coil pass a metal rod through the cylinder and mount it between two saw-horses. Before winding the wire on the cylinder, glue a band of one inch copper ribbon around the cylinder, one inch from the top and another placed three inches from the bottom. The bands should not meet, a space of about one inch being left between ends. Solder one end of the wire to the top band and start winding. The spacing between turns may be obtained by winding heavy cord alongside of the wire. Shellac liberally applied will hold the turns in place. The discharge ball is of metal and about 5 inches in diameter, mounted on top of the coil. A toilet tank float will serve the purpose very well. Complete the secondary coil by connecting a wire between the metal ball and the top of the coil. The primary coil is wound with copper or brass ribbon 1™ inches wide in the form of a flat spiral. About 53 feet of the ribbon for the 21-inch outer diameter of the 10-turn spiral winding will be required. The primary supports consist of 8 pieces of fibre 8% inches long, 2 inches wide and 1 inch thick. The four top pieces have a section cut away as in the drawing so as to keep the coil from spreading. Holes are drilled in these pieces, 34 of an inch from the ends, large enough to permit the passage of six inch bolts. The primary coil is mounted on a wooden base 37 inches in diameter with the four fibre pieces to support the pri- mary located so that the primary will be in the center o£ the board. The supports are then bolted to the base, thus holding the primary securely in place. Mount the secondary inside the primary coil on a wooden base 16 inches square, supported on four wooden blocks. Place the blocks so they rest flush with the edges at the corners of the board, and drill holes for a good sized bolt to pass through each corner of the board for mounting the secondary coil to the base. A piece of copper ribbon is soldered to the inside turn of the primary coil, and to the bottom of the secondary, winding, completing the coil construction. The apparatus is now ready for connecting and operating. The wires are connected according to the diagram. For the sake of simplicity the rotating disc is omitted in the dia- gram of the spark gap. The spark gap motor is of course connected to the input line through a suitable switch. The wire from the secondary of the low frequency transformer [Continued on page 151] Always Insist on the Advertised Brand!

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A Midget Superheterodyne [Continued from page 126| Speaker output is taken from the plate of the 33 tube and the 135-volt B battery tap. A jack is used to plug in the speaker and is installed in a grommet-insulated hole at the back of the sub-panel. ‘The speaker, of the per- manent-magnet type, should have an impedance of 7,000 ohms, or if lower, should be connected through a suitable matching output transformer. A switch at the back of the potentiometer is inserted in the grounded negative, A and B leads and positive C leads to break all circuits when the set is turned off. One side of this switch leads to the three battery taps and the other side is soldered to the chassis. A Fahnestock clip is bolted directly to the chassis and is used to fasten the ground wire. The 33 power tube has a 6-ohm rheostat in the positive filament lead for volume control. The other two tubes have 45-ohm fixed wire-wound resistors to cut the three volts supply down to two volts. After double-checking for hook-up errors, insert the plug in the battery-supply socket and connect the filament bat- teries. If the tubes light when the switch is turned on, proceed to connect the other batteries, as well as ground, aerial and speaker. Advance the volume and regeneration controls, with the 400-mmfd. oscillator padding condenser opened about half- way. All tuning should be done with a wooden screwdriver. The plates of the tuning condensers should be entirely en- meshed, so that the set will tune to the bottom of the band. Adjust the two trimmers on the i.f. transformer for the foudest hiss and crackle in the loudspeaker. These adjust- ments ‘should preferably be made during the day. After tuning the i.f. trimmers for the greatest noise, manipulate the oscillator padding condenser for the same results. When the peak is reached, the set should be near resonance. Slowly revolve the dial until a station is picked up. Adjustments may then be made on both the i.f. and oscillator trimmers for maximum volume and tone quality. World Radio Battle Looms [Continued from page 64] communications, but now the smaller countries have developed their radio facilities and are de- manding their ‘place in the sun on the ground that each sovereign entity is entitled tc its share of the valuable channels in the ether. Lightning With Oudin Coil [Continued from page 150| is automotive high tension wire; that from the condenser should be special, heavily insulated neon sign cable, as should that also from the spark gap. GREAT CARE MUST BE TAKEN NEVER TO TOUCH THE LOW FREQUENCY TRANSFORMER. ‘The condenser when charged will retain a considerable quantity of electricity for days, so it is well to “short”? the connections for a second (with a well insulated metal rod) before touching them. The grounded connections may be of braided ribbon or other heavy uninsulated wire connected to a water pipe. This ground should be a water pipe, never a gas pipe. Under no circumstances should the coil be operated unless this ground is established. The coil is now ready to be set in operation. Clip the wires from the condenser and the spark gap to convenient turns of the primary of the high frequency transformer, start the spark gap motor, and turn on the power. A loud crackling noise ‘should he heard and streamers of fire seen darting from the discharge ball. Vary the number and position of the turns used in the primary of the high fre- quency transformer and perhaps alter the capacity of the condenser until maximum output is obtained. Be sure that all power is shut off when these adjustments are made, and discharge the condensers as mentioned above before touch- ing anything metallic. An iron and nickel alloy recently patented is hard enough to scratch glass. pr i a ’ This MACHINISTS’ Home-Study Course Le heips mern oe ahead Newly assembled—specially priced—these five recent books give you the practical facts on modern machines, up-to-date methods you need to advance in machine shop work. Take advantage of the other man’s experience as found in books, to solve your problems, increase your efficiency, with the new Library of Modern Machine Shop Practice 5 volumes—2000 pages—1600 Iilustrations (A combined home-study course and reference library) This library of machine shop practice was written for practical men, Jt gives you the best methods for every kind of machine shop work. It deals fully with lathes, drills, and other machine tools and their operation, automatic screw machines, speeds and feeds, gear design and production, punch and die work, metal finishing, ete., ete. Plainly written—completely illustrated—the best kind of help to the machine-shop man who wants to advance himself. No money down—special price—easy payments | FREE EXAMINATION COUPON, McGRAW-HILL BOOK CO., Inc., 330 W. 42nd St., NEW YORK, N.Y. i Send me for 10 days’ free examination the Library of ree i MACHINE SHOP PRACTICE. If satisfactory I will send $1.5 i in 10 days and $3 monthly until the special price of $16.50 2 i paid. If not wanted, I will return the books postpaid. (To in- sure prompt shipment write plainly and fill in all lines.) | | BNET ce Sa a aana a a A encom SS Ol I OE SO Oe i FNS a a car cw an OT nO a OT a Sop ET ee j Bl Gti ced eit” a url tae eee eer ee ee i i PUTIN ee llc en etapa Re AA lS AE i GQMPAHY ssiri As a a A E D A S T E a n E MMx-7-37 60 POWER TELESCOPE $2.29 VARIABLE EYEPIECE. 20X—4OX—60X NEW! Three telescopes in one. 3 different mag- ® nifications. 20 power for ultra-bright images with 40 and 60 power Peer extra long range, Guaranteed to bring distant objects, people, sports events, ships, moon, stars, etc. 60 times as close. Most power- ful made for anywhere near the money. Can be collapsed to less than a footin length, Multiple lens system. 0 mm. objective, in heavy brass mount. Directions included for using as a compound 4 lens microscope. American made. We pay the postage. Only $2.29, BROWNSCOPE CO., Dept. 77, 234 Fifth Ave., New Yor, N., Ys SPORTSMEN’S MANUAL ORDER YOUR COPY NOW! 200 pictures PRICE 50c 148 pages At your newsstand, or order from MODERN MECHANIX PUBLISHING CO. Fawcett Bldg. Greenwich, Conn. lla tee Dede NE UJ si eS WORKS FROM ANY BATTERY! Amazing! New ELECTRIC ARC WELDER hooks up to any storage battery. Generates tremendous heat—welds all metals. Makes permanent repairs on auto bodies, fenders, radiators, sheet metal, brazes castings— stronger than before. Low power consumption. A real welder’s tool, sturdily built. FULLY GUARANTEED. SEND NO MONEY—Comet has thousands of uses in home, garage, work shop. Order now. Send no money. We ship Comet, complete with rods. “Pay postman only $1. 95, plus few cents postage. not delighted return in 5 days and we refund money. COMET WELDERS, Dept. %-154, Cincinnati, O. When Answering Advertisements Please Mention July Modern Mechanix 151

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: ge o a S O a a ee a ee a a a 152 Less Motor Drive oo Terms as Low as ropa a Month The new 9-inch Workshop Lathe is a back- geared, screw cutting lathe designed to handle the finest, most accurate jobs in manufacturing—in the tool room, in home workshops and automotive machine shops, for all classes of fine precision work. Materials and workmanship are exactly the same as used in our more expensive models of larger size, thus representing the greatest value we have offered in more than 30 years of fine lathe manufacturing. Features include: Twin gear reverse to leadscrew; Ball Thrust Bearing on spindle; Automatic Longitudinal screw feed to carriage; Precision leadscrew for cutting screw threads from 4 to 40 per inch; 34- inch hole through spindle taking collets up to 4% inch capacity. Operates from any ordinary lamp socket. Write for catalog. SOUTH BEND LATHE WORKS 520 E. Madison St.,South Bend, Ind.,U.S.Ae South Bend Lathe Works, 520 E. Madison St., South Bend, Ind., U.S.A, Please send the following free, postpaid: O 9” Workshop Lathe Catalog No. 15-U. 1) General Catalog No. 96. O Easy Payment Plan. Cs OE WOLE. 5.005 450s eo s.o5 Roabic swans RLAR PATI ies as sen anea a acorsen wate Rea rere ee aR ee AATE waa sonaas caeai CGF snargus se soia saira ia OAO i aa Ta Accept No Substitutes?! A Back-Geared Screw- Cutting Precision Lathe © IriS NITRA RIEL, PEAT NA a No. 415-YA 914” swing by 3’ bed Workshop Bench Lathe with $ 00 Horizontal Motor Drive, 14 h.p. Reversing Motor, Switch and adjustable belt tension countershaft as shown above.......... ($15.00 Doun, $6.00 a month for 18 months) 5 OTHER SIZES: 9”,.11”, 13’, 15” and 16” SWING IN ALL BED LENGTHS PRICED FROM $97 to $1200 Lathe shown below is No. 117-C 16” x 6’ Quick Change Gear Underneath Belt Motor Driven Lathe with 1 h.p. motor. *869 Complete as shown. Weight 2300 Ibs......... ($87.00 Down, $38.50 Monthly for 22 Months) Always Insist on the Advertised Brand!

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Photographing Wild Animals [Continued from page 132] first rays of dawn arrive, so get up early the next morning and close it or the film will be fogged. You will find that the small size photoflash bulb and a fine grain supersensitive film is the best combination. The small bulb lasts only 1-75 of a second, so the animal is not likely to be blurred on the resulting photograph. If more light is de- sired, two small bulbs in a double socket will do the trick. You will have to experiment to find the best stop opening to use. This varies of course with the distance which should range from one to six feet. If your camera does not have a double extension bellows for close-ups, an ordinary portrait lens is equally good. ee ee ee ee eo al pee Tapped Metal Accessories | Continued from page 130] nothing. When completed, they stand 6” high and will accommodate any number of books. As most of us do our reading at night they are very characteristic of the occasion. The material used for the body of the owl and the base is of 18-gauge soft sheet steel. Lay out the patterns on cardboard, then transfer them to the steel, cut the pieces out with the tin snips and hammer one side of each piece with the planish- ing hammer to obtain the desired effect. The lines are cut in with a blunt cold chisel while the feathers on the breast are made with an ordinary nail set held at an angle and tapped sharply. It will be noted that the base is cut so that if the finished book ends are assembled properly, the two bases will slide close together even when only a few books are to be placed in them. Drill small holes as shown in the pattern plan and assemble bases to uprights with No. 12 brass escutcheon pins. The owl’s eyes are cut from aluminum or chrome plated metal so that they will shine brightly ia the evening when the lights play on them. The beak and the feet are cut out as shown from 22-gauge soft yellow brass. These are also riveted in place with No. 12 brass escutcheon pins. Two pieces of 3/16” round iron rod 114” long are required to form a perch for the owl feet which are then bent around them. Paint the steel parts with a light coat of dead black paint, and let dry thoroughly, then burnish with a piece of fine emery paper, wearing away the paint, except in the deeper places. Glue a piece of black canton flannel to the base of each book end to prevent scratching the desk top. Medieval bronzes made in the mysterious African Kingdom of Benin are so beautifully de- signed and executed that a German scholar has said: “Benevenuto Cellini himself could not have made better casts, nor anyone else before or since to the present day.” When Answering Advertisements Please Mention J uly Modern Mechaniz INVENTORS © _ @LL PATENTS ARE WOT GOOD PATENTS There Are Many Degrees Of PATENT PROTECTION ood patent depends not only on the invention itself, but upon the skill and interest of your patent attorney in drawing up the claims and specifica- / tions and in following your case to a | successful conclusion. C, A. Snow and Company have had over 61 years of specialized patent experience. We know the difference between strong patents and weak ones. Write today for our free document: “CERTI- FICATION OF INVENTION” and our two free booklets: “HOW WE PROTECT YoU” and “SUGGESTIONS ON HOW TO COM- MERCIALIZE YOUR INVENTION.” Fill out the coupon below NOW, DEPT. C-19, SNOW BUILDING, WASHINGTON, D.C. Gentlemen: Please send me absolutely free and without obligation on my part, your free guides for inventors. NAME PURER OTETEE eR HERE THORS EEE EHH GOETH e eee P EEE EERE THEE EEE EER OEE EEEH SEES EE EERS FOTO REET THRS HEE H EEE HHO ETH ESET EEE SEEM OSES SOOSEEE SSE SESEDHOEOHES ESD OOS SEEEO OEL er coer ith a eae aE STATE i wisscvcescedsesonctce (PLEASE PRINT NAME CLEARLY) C: A. SNOW & CO. Registered Patent Attorneys Since 1875 B. S. Degree in 2 years. World famous for technical 2-year courses in Civil, Electrical. Mechanical, Chemical, Radio, Aeronautical Engineering; Business Administration and Accounting. Those who lack high school may make up work. Low tuition. Low living costs. Short diploma courses in Surveying (36 weeks), Drafting (36 weeks). Students 54th year. Enter ANGOLA, IND. "| 34 ~N (a ENGINEERING from every state and many foreign countries. March, June, Sept. and Jan. Write for catalog. 677 College Ave., HAVE YOU A RADIO IN YOUR CAR? Do you know that the Radio Builders’? Manual describes a fine 6-tube auto set? Why not get a copy and build your own? Send 50c today to MODERN MECHANIX PUBLISHING CO. Fawcett Bldg. Greenwich, Conn. Gez ALLIEDS 7% LIE TY, 5 A RAD i o ATMA T) j Send for FREE 156-page Spring 1937 ALLIED Radio Catalog—10,000 parts; dozens of kits: 53 Knight sets; Amateur gear; Test instru- ments; Public Address; books, tools, etc. Low- est prices, fastest service. BUILD MOD- ERN MECHANIX CIRCUITS. Write for Free parts lists covering: Hitch Hikers’ Portable; 2-Tube AC-DC; All Wave set; Bicycle Radio; Match Box set; 6 Volt Farm Radio; Metal Tube DX’er, and many others. f ALLIED Radio Corp., Dept. 6-G A i 833 W. Jackson Blvd., Chicago, III. 3 O Send me your new 1937 Radio Catalog. D oo Ed eo wanae a n = = HS ED CS GED Ga GD 153

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An electric wall receptacle will take five flat-type plugs. Made of bakelite with receptacle and plate of one piece. The new outlet fits any standard switch box. Permits several appliances to be used from the same outlet. A shampoo free from fatty acids and alkali usually found in soap. A cabinet shower having special attachment for producing a gentle spray for babies, a foot shower, a shower for grow- ing children and a special attachment for older persons. A high pow- ered dise edger capable of speed- ing up floor re- finishing. A condenser kit for the construc- tion of cathode- ray oscilloscopes. A welding torch črpandinç usines Duets huy ]deas An aerodynamic microphone com- bines extreme compactness, ex- cellent fidelity and novel stream- lined appearance for modern use. 154 capable of produc- ing a weld with- out sparks. A collapsible tube cap that cuts off the flow of ma- terial from the tube opening. A steel type- holder for num- bering tools, hard- ware, name plates, machine parts, etc. An automatic irap seal valve offers protection against dangers of sewer gas. A heavy duty electric etcher. An electric paper tester using an electric eye, showing variations in formation and structure. An electric hand grinder hav- a 1/18 horsepower motor. A special plier enables one to install a bulb in an auto headlight withcut possibility of breaking the lamp. It is particularly use- ful for removing corroded bulbs. A man-made sponge similar in appearance to the natural product, holds four times as much water and does not sink. A dust-free sponge rubber mattress giving relief to the asth- matic. A book of color combinations showing interior color schemes to match furnishings. A flashlight having rubber lens frame and base offers protection against damage when it is dropped. Covering also prevents corrosion. Editor’s Note—Addresses of manufacturers of these and other new products in this issue can be obtained by sending a stamped, self-addressed envelope to Modern Mechanix Publishing Co., Information Bureau, 1501 Broadway, New York, N. Y. Manufacturers are invited to submit ma-. terial for publication on this page.

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SUPER-PRESSURE STEAM secret of liners 200,000 h. F -81,235 TONS of modern superliner=— - the Cunard White Star liner “Queen Mary.” a NA so EM “Queen Mary” engines illustrate HIGH COMPRESSION feature of modern autos ARINE ENGINEERS now get more power out of every gallon of fuel oil by super-heating steam—increasing operating pressures. Automobile engineers give you more from every gallon of gasoline by increasing compression ra- tios—building modern cars with high-compression engines. Cars in every price class today offer the extra power, extra mileage, extra responsiveness that high compression gives. But to get all these advantages you must set the spark for maximum performance and use high-compression fuel! Where do you get high-compression gasoline? At pumps marked *‘Ethyl’’! Ethy] is at least six octane numbers higher in anti-knock value than regular-grade gasoline. That’s why it gives smooth, high-compression power, prevents STEAM at 440 Ibs. per sq. in. harmful knock that overheats the engine and wastes gas and ailera aaa be i oil. Ethyl assures you of 100% perform- ey a ee anée— plus all-round quality that is we Benen Wart bie double-tested—by the oil company and by the Ethy] Gasoline Corporation. horsepower is controlled. FUEL mixture is compressed in the cylinders of the average modern cars to less than one- sixth its original volume, You need ETHYL to prevent “knock” under this HIGH COMPRESSION. GETS FULL POWER FROM HIGH COMPRESSION GIVES YOU A BETTER (

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aa ‘ a = nenea a az ia SS So Foe ae ‘Luckies have been my favorite cigarette for about 5 years. They’re a light smoke that sen- sitive throats welcome. Of the many trends in Hollywood, one of the most lasting | is the preference for Luckies. | once asked a prop- erty’ man—who supplies the actors’ ciga- rettes— what the favorite is. He opened a box containing cigarettes. They were all Luckies. n4 ie A . f The Finest Tobaccos— V4 ry = MU eer N Starring in Samuel Goldwyn’'s Production ‘WOMAN CHASES MAN” Notice how many professional men and women—lawyers, doctors, statesmen, etc., smoke Luckies. See how many leading artists of radio. stage, screen and opera prefer them. Their voices are theit fortunes: Doesn’t it follow that, if Luckies are gentle on their sensitive throats, they will be gentle on your throat, too? You will appreciate the throat protection of a light smoke free of certain irritants ex- pelled by the cae ncive® ‘Toasting’ Process. Copyright 1937, The American Tohacco Company A Light Smoke | Fe S eet —Your Throat Protection ROANT COUR