Modern Mechanix, December 1937

The text was read from the page scans by machine (OCR), so it has mistakes and its columns may run together. See the pages · About this title · At the Internet Archive

Page 1

CAMERA FANS ° SEE SPECIAL PHOTOGRAPHY SECTION! : _ A ERN DECEMBER |

MODERN MECHANIX E< e. e р m oa = E m Bee = == ва. B 2<. = { E u w m ANY BUILD AN ICEBOAT SEE PAGE 72

1938 CARS

Page 2

But Doctors Win Race With Death In Dark Operating Room “Unable to sleep, I lay on my hospital bed at mid- night reading by the light of my tiny bedlamp,” writes Mrs. Mabel E. Harper, Box 468, Moultrie, > Ga. “Presently, brilliant lights came on in a wing of the building outside my window. There in the - operating room...some poor soul lay suspended between life and death, while men-in-white sought to take him from the dark angel of death! “Minutes later there was a lightning flash and the lights went out. As I wondered what they would do in the dark operating room, a nurse groped her way to my room. ‘Let me have your flashlight, quick! Where is it?... They had started to operate when the lights went out...they’ve got “EVEREADY” p Lightning Betrays menin miite- BATTERIES ARE FRESH BATTERIES The DATE-LINE guarantees FRESHNESS to continue...and a lamp is likely to cause an ether explosion!...Quick!’ “I handed her the flashlight that had lain be- side me on the table and she rushed out. *What happened? You can be sure I checked up. Those DATED ‘Eveready’ batteries, batteries that were fresh when the light was given to me, saved a precious human life. (Signed) Mabel E e pa" FEB. 1938 RESULTS FOR BEST PUT IN SERVICE BEFORE i : доз at | NATIONAL CARES. noH CeQvIEE I NO, MR. GREEN, BUT ITS THERE, 4 TEASPOONSFUL, LIKE THE MOISTURE IN | FRESH BREAD . ..YOU CAN GET NOURISHMENT OUT OF STALE BREAD, | BUT YOULL GET MIGHTY LITTLE SERVICE OUT OF STALE BATTERIES ! OKAY, MR.DAV YOU WIN. GIVE ME FRESH DATED “EVEREADY” BATTERIES

Page 3

“HE SAID my face was more or less familiar and he remembered seeing me around, but he didn't even know my name until the I. C. S. wrote him that George Jackson had enrolled for a course of home study and was doing fine work. * Who's George Jackson?’ he asked. Then he looked me up. Told me he was glad to see I was ambitious. Said he'd keep his eye on me. “Не did too. Gave me my chance when Frank Jordan was sent out on the road. I was promoted over older men who had been with the firm for years. BOX 2321-N, “THE BOSS DIDN’T EVEN KNOW MY NAME” “My spare-time studying helped me to get that job and to keep it after I got it. It certainly was a lucky day for me when I signed that I. C. S. coupon." How much longer are you going to wait before you take the step that will bring you advancement and more money? It takes only a moment to mark and mail this coupon and send it to the International Correspondence Schools at Scranton. Yet that one step may be the means of changing vour entire life. Tsn't it better to get the facts than to wait a year or five years and then wish you had? INTERNATIONAL CORRESPONDENCE SCHOOLS 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: D Architect D Architectural Draftsman [] Building Estimating D Contractor and Builder L] Structural Draftsman L] Structural Engineer О Management of Inventions O Electrical Engineer О Electrie Lighting L] Welding, Electric and Gas O Reading Shop Blueprints L] Heat Treatment of Metals О Business Management O Industrial Management O Traffic Management O Accountancy O Cost Accountant О С. P. Accountant D Home Dressmaking Г] Professional Dressmaking and Designing TECHNICAL AND INDUSTRIAL COURSES 0 Sheet Metal Worker O Plumbing O Steam Fitting O Boilermaker D Heating Li Ventilation Telegraph Engineer О Air Conditioning [] Telephone Work О Steam Engineer O Steam Electric Engineer O Marine Engineer O R. R. Locomotives О В. R. Section Foreman D Air Brakes [O R. R. Signalmen О Highway Engineering D Civil Engineering О Surveying and Mapping BUSINESS TRAINING COURSES . O Service Station Salesmanship О First Year College Subjects O Business Correspondence Г] Stenography апа Typing D Civil Service O Mail Carrier 0 Railway Mail Clerk DOMESTIC SCIENCE COURSES O Advanced Dressmaking . O Millinery О Radio O Mechanical Engineering O Mechanical Draftsman [] Machinist O Toolmaker [] Patternmaker O Diesel Engines O Aviation Engines [] Automobile Mechanic L] Refrigeration O Bookkeeping О Secretarial Work O Spanish D] French O Salesmanship [] Advertising O Tea Room and Cafeteria Management, Catering O Bridge Engineer O Bridge and Building Foreman D Chemistry O Pharmacy О Coal Mining D Mine Foreman O Navigation O Cotton Manufacturing O Woolen Manufacturing O Agriculture О Fruit Growing O Poultry Farming O Fire Bosses O Grade School Subjects О High School Subjects О College Preparatory D Illustrating O Cartooning O Lettering Show Cards [O Signs О Foods and Cookery When Answering Advertisements Please Mention December Modern Mechanix

Page 4

SAME PRICE IN CANADA SA MODERN MAN DEE CEMBER 1937 Volume XIX Number 2 Circulation over 250,000 Copyright 1937 by Modern Mechanix Publishing Co. SPECIAL FEATURES Advanced Showing—1938 Cars - - - - 35 Filming A Movie Wat - - - - - - - 42 By Earl Theisen Why Ice Boats Quadruple The Wind's Speed! 48 Herding The Mechanical Dinosaurs - - - 52 By Maxwell R. Grant Are Home-Built Planes Safe? - - - - - 60 Bungalows Of Mud = a 9 = 2 = = 64 By Robert McLean New Stamps From War Torn Spain - - - 70 By Montgomery Mulford Hitching A Microscope To Your Camera - - 94 By Julian D. Corrington, Ph.D. [Continued on page 10] A L S 0 In This Issue Modern Photography Section Designing Your Own Photo- graphic Christmas Cards - 104 Celluloid Developing Tanks Are Easy To Make - - = 106 How To Print Your Own Pictures - - - = = - 108 New Aids And Ideas For The ` Amateur Photographer = 110 Making Your Camera Pay Dividends - - - =» 4112 New Ideas For The Camera Fan- - - - - - = =114 Each month MM offers cash awards for the best pictures sent in by amateur photo fans. For full details see page 103. NEXT MONTH In addition to many interesting and novel workshop projects that will provide ample outlet for your skill with tools, readers will find many general features of an in- teresting and informative nature. Published monthly by Modern Mechanix Publishing Co., 11th St, & Broadway, Louisville, m U.S. А. Business office. 22 West Putnam Ave., Greenwich, Conn. Kntered as second-class matter under the Act of Mareh additional entry at Greenwich, Conn, Editorial offices: 1501 Broadway, New York, N, Y. at the post office in Louisville, Ky., with Not responslble for unsolicited manuscripts. In U. 8. and Possessions and in Canada, 15c a copy; $1.50 a year. Send subscriptions 19 Greenwich, Conn., address. Other Postal Unions, $2.00 a year. East Indian Agent, P. C, Eranee Sons, Bombay, India. Printed in U preceding date of issue. Advertising offices: New York, 1501 Broadway; Chicago, 3 Boc N. A. Advertising forms close the first of second month Michigan Ave.; San Francisco, Simpson-Reilly, 1014 Russ Bldg.; Los Angeles, Simpson-Reilly, Garfield Bldg. Member Audit Bureau of Circulation. W. Н. FAWCETT. Publisher RALPH DAIGH, Managing Editor ROBERT HERTZBERG. Editor AL ALLARD, Art Director THOMAS A. BLANCHARD, JOHN L. SCHERER, CLIFFORD PETERS, Associate Editors 5. 5. RABL, Naval Consultant

Page 5

Become a Draftsman Enjoy a Real Job in Industry © Steady Work As nearly all manufacturing—construction— building starts on the drafting table, the drafts- man is one of the first to be hired and one of the last to be laid off. It is his blueprints, his specifications, that give the last word in what the workmen are to do. No article—building or con- struction job is started before the plans drawn by the draftsman have been officially approved. Good Pay The draftsman has been called the Junior Engi- neer which title just about describes his work — position and pay. He combines his knowledge of principles, mechanism and construction details with the ability to draw and reproduce motions and methods on paper. On the average, his salary is con- siderably above tho wages of the mechanic and, of course, less than that of the engineer. Chance for Promotion Working on plans, helping design new machines / or new methods of construction, the draftsman is working directly with the important men of the organization. Consequently he knows what is being considered and planned. It may be the superintendent—the engineer—or even the prospective buyer with whom he / consults. Because of these contacts, his ex- perience and knowledge of the business in general he is in an excellent position to be promoted when next there is a good opening. 2 Lessons Free Test yourself — see how readily Young at 40 Athletes—farmers—and factory and shop work- ers who rely on muscle start growing old even before they reach 40 while office workers—executives —teachers—professional men, in fact, all kinds of brain-workers are just approaching their prime at 40 to 50. Training increases your value at once and continues to help boost your earning power as you mature and as you increase your experience and background for forming judgments of the firm’s policies and methods. Don’t grow old at 40. Train now for the job you want at 50. Training helps you to be inde- pendent—self-supporting. It helps you to enjoy associations that are denied the untraimed man. Training helps you to increase your earning power and by so doing to offer members of your family ad- vantages far in excess of what you could give them as an untrained man. Train and enjoy PROGRESS— CON- TENTMENT—INDEPENDENCE. American School, Dept. DD-928 Drexel Ave. at 58th St., Chicago Without the slightest obligation, send 2 beginning Drafting Lessons and free Bulletin. NOME. —————————— а АЙР —— AUD UNS, La e oic b REED M E eae Gesaan When Answering Advertisements Please Mention December Modern Mechanix

Page 6

Pr N. R. 1. Established 1914 The man who has directed the home training of more men Radio Industry than any other an in Ai study for the eri E HERE'S PROOF HAT MY TRAINING PAYS ssons, I ob- Operator's Н Ф Station - $10 а Week in Spare Time ^My work has consisted of Radi Servicing, with some Publig Mio, Set Systems work—all in my spare time. My earnings in Radio amount to about $10 a жеек.” WILLIAM MEYER 705 Ridge Road, Hobart, Ind. j Head Radio M «g am head Radio ; sl fe аи lary plu n one. of Atlanta $ beet my success (0 3 DN. ‚ САВА WAY, JR., re College Park, Ga. $200 to $300 a Month ау in Own Business "For the last 18 months I har in business for myself, making yapon $200 and $300 a month, I have N.R.I. fo апи, tor P start in this field.’— LIE Т. F HNER, 224 W, Tex: Ave., Goose Creek, Texas. ко 5. І technic: our Course а., 328 ians, and alone. Howard A RADIO ГАМУ MAKE $50575 A WEEK | Will Train You at Home— mail coupon for FREE Book Do you want to make more money? Radio offers you many opportunities for well-paying spare time and full time jobs. You don't have to give up your present job, leave home or spend a lot of money to become a Radio Expert. Many Radio Experts Make $30, $50, $75 a Week Radio broadcasting stations employ engineers, operators, sta- tion managers and pay up to $5,000 a year. Spare time Radio set servicing pays as much as $200 to $500 а year—full time jobs with Radio jobbers, manufacturers and dcalers as much as $30, $50, $75 a week. Many Radio Experts operate their own full time or part time Radio sales and service businesses. Radio manufacturers and jobbers employ testers, inspectors, foremen, engineers, servicemen, paying up to $6,000 a year. Radio operators on ships get good pay, see the world besides. Automobile, police, aviation, commercial Radio, and loud speaker systems are newer fields offering good opportunities now and for the future. Television promises to open many good jobs soon. Men I trained have good jobs in these branches of Radio. Read their letters in my 64-page book. Mail the coupon. There's a Real Future in Radio for Well-Trained Men Radio already gives good jobs to more than 300,000 people. And in 1936, Radio enjoyed one of its most prosperous years. More than $500,000,000 worth of sets, tubes and parts were sold—an increase of more than 60% over 1935. Over a million Auto Radios were sold, a hig increase over 1935. 24,000,000 homes now have one or more Radio sets, and more than 4,000,000 autos are Radio equipped. Every year millions of these sets go out of date and are replaced with newer models. More millions need servicing, new tubes, repairs, etc. A few hundred $30, $50, $75 a week jobs have grown to thousands in 20 years. And Radio is still a new industry— growing fast! Many Make $5, $10, $15 a Week Extra in Spare Time While Learning Almost every neighborhood needs a good spare time service man. The day you enroll Y start sending you Extra Money Job Sheets. They show you how to do Radio repair jobs, how to cash in quickly! Throughout your training I send you plans that made good spare time money—$200 to $500 a year —for hundreds of fellows. My training is famous as “the Course that pays for itself." THE TESTED WAY TO Accept No Substitutes! Always Insist on the Advertised Brand!

Page 7

I Give You Practical Experience My Course is not all book training. I send vou special Radio Equipment; show you how to conduct experiments, build circuits illustrating important principles used in modern Radio receivers, broadcast stations and loud speaker installations. I show you how to build testing apparatus for use in spare time work from this equipment. “This 50-50 methad of training makes learning at home interesting, fascinating, practical. You Get a Money-Back Agreement I am sure I can train you successfully. I agree in writing to refund every penny you pay if you are not satisfied with my Lessons and Instruction Service when you finish. Tl send you a copy of this agreement with my Free Book. Find Out What Radio Offers You Act Today. Mail the coupon now for “Rich Rewards in Radio.” It's free to any fellow over 16 years old. It pcints out Radio' s spare time and full time opportunities and those coming in Television; tells about my training in Radio and Television; shows you letters from men I trained telling what they are doing and earning. Find out what Radio cers YOU! MATL THE COUPON in an euvelope, or paste on a postcard —NOW'! J. E. SMITH, President, National Radio Institute, Dept. 7NH, Washington, D. C. m Dear Mr. а Radio" NAME . ADDRESS BETTER PAY EXPERT Smith: - which points out the spare time and full time opportunities in Radio and explains your 50-50 method of training men at home in spare time to Lecome Radic Experts. CITY 22 SET SERVICING. Spare time set servicing pays many $5, $10, $15 a week extra while learning. Full time servicing pays as much as $30, $50, $75 a week. BROADCAST- ING STATIONS, Employ managers, engineers, oper ators, installation and maintenance men for fascinating jobs and pay up to $2,000 a year. LOUD SPEAKER SYSTEMS. Building installing, servicing and operating publie ad- dress systems is another growing field for men well trained in Radio. AUTOMOBILE RADIO. Another new Radio ficld—selling, in- stalling, servicing. One million or more auto owners Will install radio sets within the next year. E 4 Mail this to get 64 page Book FREE J. E. SMITH, President, Dept. TNH National Radio Institute, Washington, D. C. Without obligating me, send “Rich Rewards in (Please Write Plainly.) — «STATE When Answering Advertisements Please Mention December Modern Mechanix 7

Page 8

А Frank ATENTS-| HE world of invention moves on. About a hundred years ago people were saying, “There’s nothing left to invent"—today we know that is one of the funniest things ever said. Just think what has happened in the last hundred years! Autos, radios, airplanes, and thousands of useful, practical devices for home, shop and office have been invented and put on the market. Inventors are con- stantly making the world a better place to live in. Did you see a notice in the paper that an obscure worker, Hans Wach, has invented a simple device to utilize exhaust steam on steam boats. Already, the report states, the steam ship lines have saved more than $15,000 in fuel bills with his invention. Almost in the same breath the Dept. of Commerce announces that it will soon test out a new non- crashable aeroplane, which the average man can learn to fly in a day, which will travel at 110 miles an hour and sell at the price of a cheap automobile. An unknown Seattle man has invented a robot to go 5,000 feet under the sea and recover millions and Who Are Inventors? You'd be amazed at the men we con- tact in the course of a busy year. Most of them do not consider themselves inventors at all During their work or leisure they get an idea. They Can You Answer These Questions? Ask yourself these questions: the Patent Laws protect me? steps can I take, without cost, to put myself in position to support my belief that І am the frs? man to think man to NVENTIONS millions of dollars worth of gold lying at the bottom of the ocean since the days of the early Spaniards. Remember this: For every outstanding big inven- tion there are thousands of small, simple things for use in the home, the office, the factory, on the farm, on every sort of travel conveyance. Little articles like you find on the counters of a 10-cent store, hardware store, drug store, toy and novelty shop. Many Little Ideas Have Big Commercial Possibilities A person finds something he’s using doesn’t work right, or it's clumsy, or costs too much. He gets a happy thought. He improves the old Article. That’s contribution to human progress. That's the way that many, many men have reached the gold of financial comfort, independence and even wealth. Most of the things millions of us use didn’t come from the brains of engineers and physicists. They came from the mind and maybe the crude home work bench of Mr. Average Man, busily engaged їп earning his bread and butter at whatever chance or circumstance has given him to do. The “little” man’s opportunity as an inventor was never greater than it is today. Our Business Is To Help You. Write Us Today For more than thirty-six years, this firm has been helping men with an inventive turn of mind. We maintain a large staff of trained, experienced — specialists—Registered Patent Attorneys, Draftsmen, and Searchers to help How do What easy work it out on paper. They get of my invention? Is a Patent Н д : in touch with us about Protection. f worth the cost? Do I neeg 01 clients secure all the protection to which Did you know that a dentist a model? Should I try to they are entitled. Fees are reasonable. De- invented the stock ticker, a sell my invention before Т ferred payments frequently arranged. Ques- have any school teacher the telephone, a farmer the typewriter, an tions promptly answered. Write us frankly Is E with absolute assurance that what you say will it Patented? safe, business-like way there artist the telegraph? Did med to secure financial help? Jf be treated with strictest secrecy. But FIRST, you know that the crinkly =i d. I do apply for a Patent Send for the FREE BOOKS shown on the op- hair pin—sold by millions how shall I reach people who posite page. They are filled with facts, pic- now—eame about because a husband saw his сап market my invention? Сап I protect and tures and suggestions. They tell you things wife twisting the old-fashioned straight hair pin to make it stay in place? Poor men who have no thought of invention now will be Sell an improvement on some invention that has already been patented? These are but a few of the questions which usually confront about Patents, Inventions and Selling Inven- tions that we have learned in our long experience. They may save you time, expense, EVEN LATER DISAPPOINTMENT. Simply fill in the coupon. Ne charge, no obligation. Write us today. financially well-fixed in a few years because of a happy thought that the world could use to advantage. the average man. You need the answers! YOU CAN HAVE THEM, without cost, trouble, or delay. Copyright 1937 Victor J. Evans & Co. RUSH COUPON TO WASHINGTON. D.C. TODAY 8 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 9

man talk about “SELLING INVENTIONS NEW BOOK About Selling INVENTIONS So far as we know, the facts in this booklet have never before been pub- lished by any Patent At- torney. You are given \ very definite suggestions on "When and How to Sell an Inven- i ” It also 115 Mechanical Move- ments Like These Besides many other features and facts there are 115 differ- ent mechanical movements and Principles in the big, 48-page Book below. Maybe there is just the idea you need to solve with the coupon or wrie vea card PLR Mg AW CH SES] or letter. of Facts ud. : Pictures! E VICTOR J. REGISTERED PATENT ATTORNEYS MAIN OFFICE: 220-P, VICTOR BUILDING, WASHINGTON, D. C. , Other Offices: 2610-B, Singer Bldg., New York 1145-3, Monadnock Bldg., Chicago 1010-B, Hobart Bldg., San Franciseo 105-B, Garfield Bldg., Los Angeles Send me FREE copies of your books, ‘‘Patent Protection" and “When and Ilow to Sell an Invention." (Note: Same books supplied by any of branch offices listed above.) Name ,...eseeeeensaposeectevóesosestosepresopeeesesepeosesosoo, Street and NO, „п.о hohe reset City or Town... . State... ccccseecses When Answering Advertisements Please Mention December Modern. Mechanix Ке]

Page 10

II [|

pom] == = BOOKS SENT FRE 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 п 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. GET A BETTER JOB 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 hooks а new way—without studying or memorizing. Simply use the JIFFY IN- DEX to fook up the answer to any aulo problem. Built by eleven of America’s greatest automobile engineers, and wrilten in simple language so you can understand Very newest cars, 011 covered. FREE Privilege of consulting Automobile Engineers of Amer- ican Technical Soclety for one year without cost if you mail T coupon immediately ines, etc. De Luxe edi- lon, gold-stamped flex. Books also include valuable articles on ible Service Shop Management. Ы AMERICAN TECHNICAL SOCIET Drexel Ave, & 58th St., Dept. A О, Chicago, Ill. I would like to see the new G-volume edition of your AUTO BOOKS. I will pay the few cents dellvery charges only, but If 1 choose to, I may return them express collect. M after 10 days use I prefer to keep them, I will send you $2 and pay the balance at the rate of only ЄЗ a month, until $24.80 is paid. ` Please Include free consulting jmemper stip as per your offer anove. Name --.--.2-- -

CAN YOU FIX IT? These wonder books tell step by step HOW ta take out **play" Іп dif- ferential — to killl the shimmy |n steering—to set TIMING—how to put your finger Instantly on engine trouble and then the quick expert way to FIX it. Newest im- provements fully cov. ered, Equal toa complete Lrade course at less than = a fourth the cost. it. 6 BIG VOLUMES Brand New Edition 2500 pages, 2000 illus- tratlons, wiring dias grams, ete., Including Marine Engines, Avia- tion Motors, Diesel en-

(IN AIR PISTOLS Powerful—Accurate—Eoonomical—Practical— Adjustable Shooting Force—Amazing Maximum Velocity—cal. 177 or 22and BE—For Targetand Small Game—the only Genulne Compressed Alr Pistol for Shooting BB on the market—Single # Bolt Action Hammer Fire—Heir Trigger— Safety, Price$ 7,50. Holster $2.00. Also 177 and 22 Single Shot Air Rifles $7.50.— Single Shot BB Air Rifle26.00—25 Shot BB Repeater Air Rifle $7.60—at Dealer or Direct—No license requlred—fafe for Іп» door ase, FULL DETAILS—TARGETS—FREE—WRITE TODAY, Benjamin Alr Rifle Co., 831 Marlon St. St. Louls, Мо»

New 16-inch JigSaw 1938 ''Tilting-Arbor'' Saw New Spindle Sander New Modern Styling . . New Efficleney . . Far Greater Rugoedness , , Easiest, Most Convenient to use of all Power quels tells the story of the New 1938 Boice-Crane Line. Get etailst NEW [938 CATALOG READY ,. . Write Today for your copy. Sent postpaid, include 10c for our illustrated 16 page Instruction Book on Metal Spinning, and enjoy new craft on your lathe. BOICE-CRANE COMPANY TOLEDO- OHIO

CONTENTS — Continued from page 4

SHORTER FEATURES Soaring—King Of Sports - = - = = =- 58 Winners In "Midget Mike" Model Locomotive Contest =- = = = = = - 68 HOW-TO-BUILD FEATURES A Cast Metal-Lathe Turned Dinner Gong Build "POLARIS"-—A New Hudson River Ieeboat - =- =- - - - = - - = = 72 1 -3 ү 1 -1 со Decorative Candle Holders For Christmas Brass Trimmed Nut Bowl And Mallet - An “О” Gauge Oil-Electric Locomotive Of Cardboard Construction - = = = = - 82 A Local Heat Applicator For Home And Shop Use - - - -~ - - - - 86 Blower Keeps Drill Press Clean - - - - 91 Experiments In Colloidal Chemistry - 1 eo =] NEW MECHANICAL INVENTIONS Seaplane Base Design Features "Even-Keel" Cradle - - - - - - = 44 Small Motor Powers Mower - - - - - 51 Build Largest Welded Ship - - - - - = 57 Clock Indicates World Time - - - - - 62 Surgeon Devises Special Forceps To Treat Dogs - - - - - - - = = 63 Electric Blanket Perfected - "Indestructible" Plane Built - - - - - 63 I L| 1 ' 1 e © Public Teletypes In Service - - - - - 66 Sprayer Travels Over Lawn - - - - - 67 1 I 1 сз <] Giant Flying Boats Near Completion AUTOMOTIVE Three-Wheeled Car Goes 50 Miles On Gallon Of Gas - - - - = - = - 46 *Alignoscope" Aids Motorists - - - = =- 51 Beading "Dresses Up" Auto - - - - - 62 Auto Gun Holder Invented - 66 [Continzed on разе 14] 10 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 11

LOOK UP! Read your future in the skies. Look beyond the winged fleets above... into the great plants where they are built. In those plants—creating today's planes—are men of trained hands and trained minds. Perhaps you can start YOUR career as one of these skilled craftsmen, It takes certain rigid quali- fications—but you may possess them. It takes highly specialized training—but that is easy to obtain. 4 you will find an institution operated exe i D clusively to provide worthy men with this 5 special training. Four modern new build- ings on a five-acre campus . . . a complete ® assemblage of the most advanced aircraft plant equipment, put at your command the finest training facilities in existence. You learn actual airplane production technique— the whole training system places you under the su- pervision of the aircraft leaders on the Aero I.T.l. Executive Board. EXECUTIVE BOARD ROBERT E. CROSS, President, Lockheed Aircraft Corporation JOHN K. NORTHROP, President, The Northrop Corporation C. A. VAN DUSEN, Vice President, Consolidated Aircraft Corp. If you have the vision to picture YOUR future in aviation's great future, Aero I.T.l, training is the kind of preparation you will want. You will have the tremendous advantage of training in Southern California—the world's greatest center of aviation activity. For complete information, get the FREE booklet, “Моге Planes." Find out about Aero I. T.I. resident courses... also the combination course, with theory at home and later shop training. Send the Coupon Now! 5965 West San Fernando Road Los Angeles, California s , inc. VeRO INDUSTRIES TECHNICAL es. Cali. [pus Mur eee doe Planes." | am 18 years of ag oklet 2 in snd m furnish character references e When Answering Advertisements Please Mention December Modern Mechanix 11

Page 12

Page 13

Keen competition in every form of in- FREE RECORD dustry has put manufacturers feverishly ФЕ INVENTION at work trying to speed up output, reduce FORM This FREE overhead, save on materials, outsell trade Record of In- opponents. The inventor is the key-man enables you to make in cone i ine i venient form a skelch of your in making advancement possible to апу yenlent form а sketch of your business. Upon the inventor rests the nessed in a manner of value success of many enterprises, to you should. е. occasion This does not mean that you must have TUE COUPON TODAY something gigantic to win commercial бог А our REB Success. A new way to open а door Invention Form. or button up a shirt may be the very thing hundreds of manufacturers are looking for. If you have something novel — it is practical to manufacture— no matter whether it be an improved rattle for a child or a whistle for & mechanical automobile. there is likely a wait- ing market. Importance Of Immediate Action In making application for pat- ent it is ол to be first, TEAR OFF Even if your application is de- AND layed by a few days you may MAIL be placed at a disadvantage. The short time that elapsed be- NOW! tween Elisha Gray'sapplication for his telephone patent and the application of Alexander Á , Q CLARENCE A, O'BRIEN & HYMAN BERMAN 3177 Adams Building WASHINGTON, D. C. Registered Patent Attorneys Botore U. S. Patent Office Please send me at once your Big Free 45-Рағе Book, ‘‘Patent Guide for the Inventor" and your Specially Prepared “Record of Invention" form. This request does not obligate me. Graham Bell probably cost Gray the rights to the tele Ф с pho ne. (Please write or nrin plainly) ccm = ече зс ISI MEC" When Answering Advertisements Please Mention December Modern Mechanix 13

Page 14

WELL 272си YOU FOR GOOD JOBS IN ELECTRICITY DIESEL ELECTRIC POWER ... RADIO: REFRIGERATION ... AIR CONDITIONING “ON PRACTICAL EQUIPMENT ERES 25 in your own home IN YOUR SPARE TIME Getintoa growing industry that of- fers steady work, better jobs, good payand a real future. Revolutionary new plan brings practical training right to your door. Learn at home... do actual jobs in your own electrical workshop . . fwe furnish dozens of items of electrical equipment at no extra cost with the course to make training easy and help you earn extra spare-time money. EARN WHILE YOU LEARN) ‘There's no need to give up your present job until you are trained ботап electrical job... opportunities to! make $5, $10 or more a week while training . .. your spare time is enongh to learn Electricity the FERE Li d practical E.I. way. Keep [right on earn- sae ing as you learn. You don't need previous experience or a Jot of book learning. Money back if not satisfied. Mail the coupon TODAY for big Free Book and alllacts about tbis amazing new plan of home shop training. There is no obliga- tion and no salesman will call on you, ELECTRIG INSTITUTE, ! H. W. Petersen, President E Dept. 47 inet INSTITUTE, Inc. insdale, nois f " a “Send Free Book and full details of E. I. Home Shop Training. Name. cacceseccccescccccccsssceres Аге... I show you how to greatly In- PO U LT RY ness, or secure a sood job in a big poultry plant. I tralu you at home SS EA 4 \ ч Give you facis worth money to yourself or employer. Men and women in small towns or suburbs will he Ulam man nsu men rum pass nias pua GR Бина RE BUS ee UNE ЕЗЕР ЧЕНЕ) UN URN crease profits, start your own busi- in spare time quickly. Show you very latest methods. particularly interesicd because latest scientific methods mean unusual profiis for them. Му home- study course used by thousands. 32-page book, “Ilow to Raise Poullry for Profil" FREE. Mail coupon today. SCIENTIFIC POULTRY RAISING HARRY M. LAMON., Pres., National -Poultry Institute, Dept. 136-C, Adams Center, N. Y. Please send me your FREE Book about poultry raising, and facts | comes {о you about your Course. Pays Up to $2 or $3 an Hour —Start in Spare time NO EXPERIENCE NEEDED to file hand. band and circular saws with FOLEY Automatic Saw Filer. J. W. Anderson, Texas, writes, ''Mv fourth yea with Saw Filer and third with FOLEY Lawn Mower Sharpener as side line. Business has in- creased until it is about full time.” Used by Leading Saw Makers Atkins, Disston, Simonds and by industrial Plants and repair shops all over U. S. Cash work. No canvassing. No eye strain. Posteard brings FREE PLAN and special offer of Foley Saw Setter free. No obligation. FOLEY MFG. CO. 1217-7 Foley Bldg- 11 Main St., N. E., Minneapolis, Minn. CONTENTS — Continued from page 10 Flanges On Wheel Prevent Tire Blowout Accidents - - = = = = = = 66 Car Serves Home, Business - = = = - - 69 88 90 Simplifying Winter Starting - Li [| 1 1 Auto Repairing Time Savers - FOR THE WORKSHOP FAN Winter Sports Projects - ~ - - - - - 76 Simplified Toboggans Provide Winter Thrills 77 Kinks And Gadgets For The Home Workshop 84 Kinks That Simplify Home Tasks - - - - 85 RADIO Special Engine Powers Radio - - - - - €9 Radio Sparks - - - - - - - - - - € The Cause And Cure Of Radio Noises - - 98 Euild This Two-Tube “Amateur Special” - 100 DEPARTMENTS Solving The Readers’ Problems - - - - 18 Chips From The Editors Workbench - - 23 Nic Sprank’s Oddities - - - - - - - 55 MISCELLANEOUS Campbell Sets Boat Record - Builds Novel Model Exhibit - - - - - 4 Builds Tiny Bikes As Hobby - - - - - 47 College Teaches Yachting - - - - - 47 Lifeguards Use Surfboards - - - - - = 50 Tots Study “Stop-Go” Lights - - - - - 50 Wire Fence Balks Bridge Jumpers - 50 Amateur Photo Fan Snaps Picture Of Rare Lightning - - - - - - = = 51 Plumbing Fittings Make Novel Football Display - - - - -- - ~ 57? Nurse Corps Uses Airplanes - - = = - 57 Fleet Of 398 Planes Tests London’s Air Defenses- - - - - ~ = Headline Hunter Preserves Old Newspaper Copes - - - - =- - = - 69 14 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 15

сам омор мео WEST! STABLISHING new mileage. records on cars in all sec- Guaranteed Gas Savings tions of the country, the Vacu-matic again scores in a new speed record established by Bob McKenzie transcon- VACU-MATIC must prove itself on every саг, ft ls tinental automobile champion. Los Angeles to Chicago — с to give worthwhile gas savings, quicker pick-up 2,322 miles in 39 hours and 42 minutes— driving 75 and 80 Fe more power, or it costs you nothing, “On my V-8 to maintain a speed average of 59.7 miles per hour! vdi works miracles [Г Ralph Fields, James Seeley Here is speed—a gruelling иши аш. paier land, 385 miles it Ed i a can d à v. c greater top speed — and less stops for gasoline mean those —"On the Buick i я " Е ДЕ precious moments saved that make new speed records possible n the Buick it showed 5 miles more per gallon.” F; à ees Ps S. Peck—I average 22 miles per gal. on my Plymouth, The same Vacu-matic that helped Bob McKenzie оа завеш an increase of 7 miles, for a saving of $15.00 a month, or record and gave him such fine gas savings is now available foc all, n Ar Е З car owners, Jt is positively automatic—simple to install—inexpen- кодда Mod үү Lyons— Averaged 25 miles on a, sivé—and pays for itself many times over in gas savings gal. with a Model A Ford at 40 miles per hour, Lorna oz ae Nothing Like Ir! Free Details Vacu-matic is entirely different! It operates on the super: А charge principle by automatically adding a charge of extra You owe it to yourself to know all about this remarkable oxygen, drawn free from the outer air, into the heart of the discovery. Mail the coupon below. Start saving gas with gas mixture. It is entirely AUTOMATIC and allows the WACU-MATIC and enjoy a new driving thrill! There's motor to "breathe" at the correct time, opening and closing ПО obligation—so get the facts now! Write todayl automatically as required, No idl- Agents and ing troubles—no carburetor adjust- - о wFREE OFFER COUPON e a u Salesmen | 181" necessary. It is so simple it ^ THE vACU.MATIC COMPANY will amaze you-—so practical it will 7617-341 W. State St, Wauwatosa, Wis, ч L| VACU-MATIC offers | save you many dollars on gas costs. Gentlemen: Please send me full particulars concerning tho [| 4 “a splendid opportunity Vacu-matic and details of your Free Offer. This of course for unusual sales and Fits АП Cars does not obligate me in any way. profits. Valuable terri- | VACU-MATIC is constructed of six tories now being as- | parts, assembled and fused into one unit, signed. Check and mail | correctly adjusted and sealed at the coupon. factory. Nothing to regulate, Easily Address ..... attached in ten minutes. ` City эзен Кака ssnipe States „оон ока The VACU-MATIC Co. Wauwatosa, Wis. ra Г] Check here if interested in selling propositlon. E J ат = Se See в жъ шь um эш ыў Name .... te*essetotenstnsaessósóosesecavettdpcssAN N = жа шэ -— з =з «ер When Answering Advertisements Please Mention December Modern Mechanix 15

Page 16

SEND A DIME | For The Book of 16 PLANS Delivered Postpaid 16 complete, detailed, easy-to-follow plans for making useful articles at home; specifications and list of stock included for each. All com- piled into one booklet: "Things To Make In Your Home Workshop” Plans for making these projects: Work Bench Circus Toy Tool Cabinet Boy's Desk and Stool Sawhorse Adirondack Lazy Chair Book and Magazine Rack Combination Table- Cupboard Folding Breakfast Unit able Window Cornices Cape Cod Cottage Drop Leaf Coffee Table or Birds ALL 16 FOR 1 DIME Mail us your address with coin or stamps NOW STANLEY TOOLS 108 Elm Street, New Britain, Conn. Wall Bookcase Airplane Model Portable Sewing Stand Modernistic End T. It's Fun To Learn This Way —At Home—In Your Spare Time You know that drawing will give you pleasure and recreation after your day’s work is done. We offer you a training in COMMERCIAL ART, ILLUSTRATING and CARTOON- ING, all in one practical course. Art Offers You Pleasure and Profit If you are fond of drawing, our course of training will help improve your drawing ability. Later, with continued drawing practice, you may qualify your- self for a pleasurable and profitable career in this field. Our free book, “Art for Pleasure and Profit,” gives full particulars of our course and the opportu- nities in this field. Address your request for this book to WASHINGTON SCHOOL OF ART 6 STUDIO 2012A ' 1115-15th St., N. W. WASHINGTON, D. C. Gauge Measures Paint Coat N ELECTRICAL gadget so sensitive that it can accurately measure the thickness of paint lacquer or enamel on a steel surface has been developed by a leading automobile manufacturer. The operation of the gauge is based on the simple theory of balancing an unknown electrical resistance against a known electrical resistance and reading the result from a dial on which a needle is mounted. Device Tests Exhaust Gases AS EXHAUST gas analyzer device that makes valuable data on the operation of various types of internal combustion engines available has been developed by a New York manufacturer. The machine is readily port- able.and can be operated by a 6-volt direct current motor powered by an automobile storage battery or by a motor connected to a standard lighting circuit. The device determines the air-fuel ratio by a mechanical principle based on the fact that the specific weight of exhaust gases varies with changes in the air-fuel ratio. To obtain substantial force as a means of meas- uring the specific weight of the exhaust gas being tested, a rotating motion is imparted to the gas by a motor-driven fan revolving in a chamber. The fan blows the gas against the blades of an impulse wheel, thus producing a torque on the shaft of the wheel in proportion to the air-fuel ratio which registers on a calibrated scale. 16 Accept No Substitutes! Always Insist on the Advertised Brandt

Page 17

500 HOURS OF THRILLING _. FUN ч B You step into а dazzling 92 © new world when you own the great new Speed Erector. With your own hands you can make dozens of mighty mechanical marvels that hum with action. Hook up the powerful Erec- tor electric engine and that Bascule bridge actually opens and closes. The fer- ris wheel goes ’round and ’round. The airplane beacon revolves. The magnetic erane raises and lowers—swings to the right or left—grabs up steel girders be- fore it touches them. There are more thrills — more hours of fun ——in an Erector Set than anything else you can own. Tell Dad the great new Speed Erector is what you want most for Christmas. PACKED — IN ONE ERECTOR SET mes ES ө It's a humdinger, boys, this new No, 814 Erector Set. The greatest development of the famous Gilbert Hall of Science. Contains over 15 lbs. of parts. Red, yellow and blue girders and structural plates. shells. Big red wheels. A powerful 110 volt electric engine that reverses. Gears, pinions and other parts for building more than 100 giant, realistic engineering mar- vels. Its price is $12.95, and there are other Erector Sets from $1.00 to $27.50. Glistening boiler et SY NL SE OS SS SS LE A A MEI ND must ences m ~ 7 sq. ft. *How-to-Sell-Dad" Poster, Shows new Speed Erector in life size and full colors. Also, "Gimme" card to help you get what you want for Christmas. Send coupon or 10 post card. A. C. GILBERT CO. 13 Erector Square New Haven, Conn, Quick! Send me your colossal “How-to-Sell-Dad” Poster and “Gimme” card—both Free. When Answering Advertisements Please Mention December Modern Mechanix 17

Page 18

Editors Note: not require special research or involve trade secrets. Names and addresses of manufacturers of new products de- scribed in this issue can also be obtained free upon request. ^ Enclose a self-addressed and stamped envelope for Your questions will be answered personally and free of charge by MM experts provided they do reply. Address: RESTORING FADED WRITING While cleaning out our attic I ran across some very old letters in which the writing (ink) is faded so that it is almost illegible. Is there any way of restoring the writing? —John White, N. Y. C. Writing on old manuscripts or letters can be restored by rubbing over it a solution of ammonium sulphide, hydro- gen sulphide, or “liver of sulphur.” This treatment will not restore writing in aniline ink, working only with ink that forms a black sulphide. Try it on your letters, A SATISFACTORY AMBER CEMENT Can you supply me with information as to how to make a cement that will be satisfactory for use on broken amber? —Fred Weckworth, Leonia, N. J. Moisten the pieces to be joined with caustic potash and press them together when warm. The union will be so perfect that no trace of the juncture is visible. Don’t forget to warm the amber first. REMEDY FOR HORSE BLISTERS Several of our horses have developed blisters due, ap- parently, to harness friction. Can you provide me with a simple and cheap remedy?—James Connors, Rosendate, N. Y. We would advise you to seek the services of a veteri- narian unless you are sure that the blisters are of the common type. For treatment of common blisters use tincture cantharides, 1 ounce; camphorated oil, 14 ounce. Apply three times daily. COMMON WEATHER FORECASTER As a boy I used to prepare a small piece of cloth with some chemical solution so that by changing color it would indicate a change of weather. Can you supply me with a formula as I have forgotten the ingredients used?—Jack Smith, Yonkers, N. Y. Make up a solution of 1 quart of cobalt chloride; 75 paris of nickel oxide; 20 parts of gelatin; 200 parts of water. A strip of cloth, soaked in this solution, will appear green in clear weather and will lose its color when damp weather approaches. 18 Problems Editor, Modern Mechanix Publishing Co., 1501 Broadway, New York City, REMOVING RUST SPOTS FROM LINEN Please give me some advice as to how rust stains can be removed from linen fabrics.—Martha Burke, Lynbrook, L. T. Dissolve potassium bioxalate, 200 parts, in distilled water, 8,800 parts; add glycerine, 1,000 parts, and filter. Moisten the rust spots with this solution, letting the linen lie for 3 hours. Rub the rust spots frequently during the 8 hours and then wash well with water. WIND TUNNEL FOR MODEL PLANES Several months ago you ran an article on flying titled "Is There A Speed Limit?" in which frequent reference was made to wind tunnel tests of airplanes and airplane models. Do you know where I can obtain plans and instructions for building a small wind tunnel in which ordinary airplane models could be tested?—Paul Rappaport, Philadelphia, Pa. Ап article and plans for constructing a small wind tunnel for model airplanes appeared in the 19323 edition of the MM FLYING MANUAL. You can obtain a copy by sending 50c to our Greenwich, Conn., office. TO BLACKEN ALUMINUM SHEETING 1 am interested in learning some method of blackening aluminum sheeting, Can you supply me with such infor- tion?—Thomas Cox, Boston, Mass. The surface of the sheet should be polished with very fine emery powder or emery cloth. After polishing, pour a thin layer of olive oil over the surface and heat slowly over an alcohol flame. Large sheets can be heated in an oven. Under the: action of the heat the plate will first turn brown, then black, according to the degree of heat. FROSTING MIRRORS FOR DISPLAY USE Kindly inform me as to the proper method of frosting a mirror so that desired designs, etc., can be sketched upon it—Joseph Di Castro, Detroit, Mich. Make a mixture of 4 ounces of sour ale and 1 ounce of magnesium sulphate and apply to the mirror with a small, clean sponge. Allow to dry, after which the artist can make his sketches, using any desired colors,

Page 19

4900 Chemical Formulae In This One Indispensable Book In this one big book you have at your fingertips practical commercial for- mulae for making thousands of useful products for your own use and for profitable manufacture. Brand new, encyclopedic in scope, arranged for quick reference, it is exactly the book that every commercial chemist, large or small, has long wanted. 600 Meaty Pages of formulae including many patented, scarce and little known processes, many published for the first time. Collected by over 60 outstanding industrial chemists and technicians-every formulae proved suc- cessful by actual test and experience. Covers Hundreds of Industries Thousands of Products You will find, in The Chemical Formulary, methods for making or using Abrasives Disinfectants Hair Tonics Patent Leather Adhesives ncense Photographie Air Conditioning Elecirotyping Inks Specialties Alloys Etching Insulation Polish, Auto Anti-rusts Compounds Jams and Jellies Porcelain Aromatics Explosives Kalsomines Preservatives Asphalt Fertilizer Lacquers Printing Bronze Lacquers Fireproofing Latex Paint Refrigerants Candles Fireworks Leather Polishes Rubber, Synthetic Candy Glaze Fluxes Liniment Safety Glass Carbonizing Fly Killer Liquors Shaving Cream Catalysis Food Specialists Lubricants Soaps Celluloid Gems, Artificial Matches Solvents Cement fa Glass Polish Metallic Printing Stencils Coffee Substitute Glues Matrix, Rubber Tooth Paste Colors for Oils Gold, Plating Mirrors Waterproofing Decolorizing Grease Nickel Plating Zine Etching Lubricating 011 Sun-Tan Dental Cement air Setting Ointments and thousands Depilatories Liquids Palnts more ONE FORMULA ALONE MAY BE WORTH HUNDREDS OF DOLLARS TO YOU Every formula in this book is of practical, value. The volume is not merely a collection of “household stunts” or experiments for the amateur, but a mine of money-making ideas for everyone concerned with commer- cial chemistry. In addition, you will find a quick-reference book for a vast amount of information that you need in your daily work. Send for your copy tday. EE IT FREE Send No Money Mail This Coupon | D. VAN NOSTRAND CO. 250 Fourth Ave., New York Send me on approval The Chemical Formulary. Within 5 days after I receive it, I can return it to you and owe nothing. If I Keep it I willl send you $2.00 as first payment and I will pay | Preparation Zine Plating commercial $2.00 monthly thereafter for 2 months—$6.00 in all. (590 dls- (M. M. 12-37) Name | count for cash. Sa-ne return privilege.) — MÀ a ч ж — а When Answering Advertisements Please Meution December Modern Mechanix THIS COMPLETE, SIMPLE, PRACTICAL COURSE FOR SELF-INSTRUCTION WILL QUICKLY GIVE xou A Complete Mastery оў. MATHEMATICS Prepare now to advance yourself to an important job by Mathe- matics Training. Mathematics is the foundation of all me- chanical and scientific work, and of all business or industry ‘based on science. Without this essential knowledge even the most capable man is left be- hind while others forge ahead to better jobs, bigger contracts, more money. You need mathe- matics to solve technical prob- lems and to improve, speed up and check on your work and the work of others. Now you can learn mathe- matics by an easy, inexpensive and time-saving method. А very simple and extremely in- teresting course in book form has been prepared for you bv an expert who has devoted a lifetime to teaching practical men the fundamentals of this important subject. MATHEMATICS FOR SELF-STUDY By J. E. Thompson, B. S., A. M., Dept. of Mathematics Pratt Institute These books start right from the be- ginning with a review of arithmetic | + A Complete that gives you all special short-cuts Course and and trick methods that save ccunt- less hours of your time. Then they Reference £o right into higher mathematics Library in and show you how simple it is wira an expert explains it for you. n 5 Volumes no time at all you will be tackling Arithmetic with ease the most difficult ques- Algebra tions on this subject. Seometry An Expert’s rigonometr : Kalenidw — Simplified Methods Mr. Thompson, the author of 1598 Pages Illustrated these books, has had many years’ - experience in mathematical train- ‚ ing. He presents each practical method and problem in the | clearest, simplest way. He gets right down to the kind of information that you need in your daily work. Send No Money — Mail This Coupon for FREE EXAMINATION Пе ч= ша аш пы пи m m m иш пш пп иш иш ип пп ап пш аш UR NR аш пп GN аш UD ш ш шпн Jw) D. VAN NOSTRAND CO., Inc. 250 Fourth Ave., New York Send me MATHEMATICS FOR SELF-STUDY in 5 volumes, Within 10 days I will either return the books or send you $2.95 as first payment and $2.00 per month for 3 months—total $8.95 (5% discount for cash). (М.М. 12-37) Хаше Address City and State.......e.seesevesseveosososesenenee serrer Reference Address ,.... eee ce кик nee tenant ener erste жа канаа O FOR FREE CATALOG of best books of practleal Instructlon and J technical information, check here. If you do not want Mathe- matics for Self-Study cross out paragraph above, + 19

Page 20

: e, n vprestone" anti free? , YORK. ES; NEW E GENERA о UNION CARBID Ni I DON'T KNOW WHAT WE WOULD HAVE X DONE IF YOU HADN'T COME ALONG . oo WE'RE NEARLY FROZEN | GET RIGHT IN | FOLKS,WE'LL | HAVE YOU HOME | IN NO TIME. > 20 EREADY THEY TOLD ME IT WAS Y JUSTAS GOOD..BUTIT | MUST HAVE BOILEDAWAY f | DURING THE WARM $ | SPELL LAST WEEK. Й “NEXT TIME, NEIGHBOR, GET THE GUARANTEED ANTI-FREEZE . . . READ THAT. ..THERE'S NOTH- ING ELSE LIKE IT!” TRADE- ANTI-FREEZE IS Accept No Substitutes! Always Insist on the Advertised Brand!

Page 21

Aane all the brands available to U. S. motorists, there's no other anti-freeze like “Eveready” "Prestone." This anti-freeze is guaranteed, insures you against FREEZE- UP, BOIL-AWAY and RUST-CLOGGING, the three winter Е purse-snatchers that cost American motorists millions of dollars every year. € But when you gamble on anti-freeze you risk more than money...you take chances with your family's health and safety, hazard all-winter comfort, wreck your peace-of -mind. € Every year millions more decide on safety, demand “Eveready” “Prestone” anti- freeze. So perhaps you should get yours early... Today, for example. Buy "Prestone" anti-freeze from dealers who are prop- erly equipped to service your car for winter driving. MARKS GUARANTEED IN “Writing When Answering Advertisements Please Mention December Modern Mechanix 21

Page 22

USEFUL INVENTIONS DESERVE PATENTS Many inventors have not reaped the benefits of their inventions . . . because they did not obtain strong patents. Are you adding your name to this pathetic list, or do you realize the value of good patent protection? As Registered Patent Attorneys before the United States Patent Office, our prac- tice is confined exclusively to patents, trade marks, copyrights, and includes every branch of the business. We pre- pare licenses, contracts and agreements, and give legal advice to our clients. Every case is treated with the strictest confidence. PROTECTING YOUR INVENTION Do you know how to obtain a patent? How to go about seHing it? What makes a patent valuable? Do you know the importance of absolute secrecy in patent matters? Do you know what can be patented? Do you know the cost of а patent and how you may pay for it on convenient terms? We will answer these and many other questions tor you absolutely free, C. A. SNOW & CO. have had over 62 years’ experience in patent matters. We have secured thousands of patents for our clients, in every field of invention. Our free booklets on patent matters answer questions every inventor wants Se They are free. MAIL THE COUPON C. A. SNOW & CO. Registered Patent Attorneys Since 1875 а Н Dept. C-23, Snow Building, Washington, D. С. € Н Gentlemen: Send me your free handbooks for Н Н inventors by return mail. No obligation on my x H part. Н s Li Н [pi [TEE И п Е а п е ADDRESS wii ise eee ror Ea ara Re ei eere ea жк ov H H H H GUT c STATE. iui ex 1 аналанивпапиваванпанпаванаплананвинаваппвавананананвавяятапакай Model "Flys" In Wind Tunnel HE National Advisory Committee for Aero- nautics has added a “free flight” wind tunnel to its world famous laboratories at Langley Field, Va. Through the use of exact scale models, the new tunnel enables studies of airplane stability and control to be made on a more advanced scale than was possible in the past. To use the “free flight” wind tunnel, a model plane is set at its gliding angle and air is blown at the model until it “takes off.” Ailerons and rudder are controlled by magnetic devices set within the wings of the tiny aircraft. Mid-Wing Lockheed Tested MID-WING version of the famous Lockheed Electra airplane has been developed and tested by the Lockheed Aircraft Corporation of Burbank, Calif. It is said to be larger, faster, and to have a greatly increased payload capacity. The usual two rudders and vertical fins of the Lock- heed design are featured in the new plane. Known as the Model 14, the new plane provides luxurious accommodations for eleven passengers, two pilots, and a stewardess. Two engines of 1,000 horsepower each are housed in nacelles fitted into the leading edges of the wing. Although per- formance figures have not been disclosed as yet, engineers claim that the Model 14 will be the fast- est transport plane in the world. The cabin of the plane is air-conditioned and completely sound- proofed with a non-inflammable material. 3,700 Phone Calls at Once So large is the switchboard of the telephone system in the newly opened Department of In- terior at Washington, D. C., that 3,700 calls can potentially be handled at once. 22 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 23

"New Small Metal Working LATHE Machinists, model makers, jewelers, home craftsmen—they’'re all talking about this amazing new lathe. You will, too, when you see it. All the famous features of the larger Atlas lathes are right here for you in this small deluxe model. It’s a back-geared screw-cutting lathe with 16 speeds, re- “ee Timken bearings, and many other features. There are two sizes—12” and 18” between centers——6" swing. Prices are only $59.50 and $64.50, complete less motor. There’s never been a value like this before. Ask your dealer to show you this sensational new Atlas, or send the coupon below for соте versible power feeds, integral countershaft, V-belt drive, plete information. 9" and 10" Р ха Metal Working New! Precision Aue) EAR All the precision and power of large machines built down to scale, 7” stroke, 4 speeds, 5 surface feeds in either direction. $215.00 with guards, сва L.C The most modern bench lathe, Everything you need and want for precision work and easy operation, Many extra exclusive features. $59.50 to $122.50. DRILL PRESSES Four sizes and prices to fit every need. New Atlas ball bearing spindle construction assures greater accuracy and longer life, $17.75 to $45.75. MOTORS & GRINDERS $10.25 and up ARBOR PRESSES $13.25 and up ATLAS PRESS CO. 1252 М. Pitcher St., Kalamazoo, Mich. . Kindly send me your new [938 Catalog, WOOD LATHES—Deep grooved SKF hall hearings assure long, accurate serviee at high speeds, $24.95 to $33.95. 1252 N. Pitcher St. ATLAS PRESS CO. JU ошол FACTORY DISPLAYS AT CHICAGO—35 E. Wacker at Wabash NEW YORK—130 W. 42nd St. PHILADELPHIA—113 N. 3rd St. When Answering Advertisements Please Mention December Modern Mechanix 23

Page 24

a ТИТИ (5 Your Job Safe? Just as thegasoline engine changed the jobs of thousands who depended on horse-drawn | vehicles for their living—so now the Diesel оне is fast invading both the power and E riesen Jobs e fields, and threatening the ў present jobs of зората Diesel engines are replacing steam and gasoline engines in power plants, motor trucks and busses, locomotives and ships, aircraft, tractors, | dredges, pumps, etc.—opening up ‘well-paid {ора for Diesel-trained men. You get all the atesb Diesel developments in our course, Special diagrams for quick understanding of this new power. | « Men Over iom Under (а "— in your own home; learn about Diesel li This opportunity is open to s under No experience necessary. At our expense, see how plain eve; oint 18 or men over 40. But if you are WITHIN is made—how thoroughly you grasp it—how Еау you wilt ООУ ll these ages, you owe it to yourself to investi- the work. If you are over 18 and under 40, send postcard, state age, gate this opportunity of acquainting yourself and get 2 beginning lessons FREE. No obligation. This may be the: li with Diesel—the new, fast-growing fleld. turning point in your life, so write TODAY! l AMERICAN SCHOOL, Dept. D 928, Drexel Avenue at 58th Street, Chicago, Tilinois fest Yourself for a Good Pay Job—Steady Work АТ НАР TYPEWRITER “kite EASY abar TERMS Saveover 507,08 any standard model, Also PORTABLES at big reductions, Write Pruitt first. SEND NO MONEY Late models factory reconditioned: В ae cision tested for emooth writing, Lo like brand-new. Free 10-DAY RRE Send at once for FREE illustrated circular showing actual machines, low- est prices, and complete information Get Started Now In New Boom aeiy New, Practical and Simplified Book Shows How Survey shows 5000 men needed in air conditioning every oo for nekt n vere Noy America A ASK FOR astost growing industry. Refrigeration booming too, Thousands of new jobs, Two new practical CATALOGUE books get you started іп this good pay work. "'Air Conditioning" by Reisbeck, 369 pages. 89 illustrations, $3.50. ‘‘Electric and Gas Refrigeration" by Althouse and Turnquist: 850 pages. 385 illustra- tions, 17 in. colors, $5.00. Send name and address and book wanted on post card, Deposit price plus few cents postage with postman. Return in 3 days if not satisfied and money will be refunded. Cata- 5955552593 i P CE Books ТИЕШ, GUARANTEED about our money-saving Offer. PENAOI say "HOBDHEART- WiELeOX со., Free 10-Day Trial e Shorthand & Typing Course Free! Dept, [9, 2009 Michigan Ave., Chicago PRUITT CORP., 758 Pruitt Bldy., CHICAGO, ILL, MAN IN EACH ТОМА PUCHSTEINS IRSE, uiu o Plate Auto Parts cool, neat, light. Guaranteed 5 years. Easy payments. Send Reflectors, Bicycles, Fixtures, Mirrors, by Iate method. Simple for Catalog today. plan of manufacturing at home starts you IN GOOD PAYING : BUSINESS. Write today for FREE particulars and proofs. l.Buchsteln Co, GUNMETAL CO., : 6i03rd Ave. 50. Ave, Р, Decatur, IIl. Also fibre atms, and Minneapolis braces for all deformities. Minnesota С а. | ` е Easy Lesson NOW FREE- ‘Big Free book in colors tells new easy way, You don't need experience, We show you how {о decorate beautiful Art Novelties right in your own home by simple ““8-з{ер” method. ‘No tedious study, Everything furnished, including supply of Noveltles for you to decorate and Homecrafters Outfit, Big profit per piece for decorating. Мапу sit at home, and make up to $25 to 850 a week—full time or spare time. t I abso- WRITE FOR FREE LESSON {уй "Sart rigot in decorating Glits, 2i)» Bridge Prizes, Toys, etc. More like fun than work and you earn as you learn. Hundreds — үн = "= та ш нз ли ш ш ш иш mom making blg money this fasclnating way. FIRESIDE INDUSTRIES, Bi 1 " 1с No Canvassing zou qu femme in penang Please send big Free Book and pay now. We are so sure of your satisfaction FREE LESSON. This does not obll- that we give you an absolute Warranty backed gate me in any way. by $1,000 Bond. Costs nothing to find out. Name _—--—--—----------------- Openings for new workers now in every locality. Addres: Mail coupon immediately for Free Book and Sc iem Free Lesson. Get started making money at once. 24 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 25

ПШ me! Copy this girl and send us your drawing — perhaps you'll win a COMPLETE FEDERAL COURSE FREE! This contest is for amateurs, so if you like to draw do not hesitate to enter. Prizes for Five Best Drawings — FIVE COMPLETE ART COURSES FREE, including drawing outfits. (Value of each course, $215.00.) FREE! Each contestant whose drawing shows sufficient merit will receive a grading and advice as to whether he or she has, in our estimation, artistic talent worth developing. Nowadays design and color play an important part in the sale of almost everything. There- fore the artist, who designs merchandise or il- lustrates advertising has become a real factor in modern industry. Machines can never dis- place him. Many Federal students, both men and girls who are now commercial designers or illustrators capable of earning $1000 to $5000 yearly have been trained by the Fed- eral Course. Here’s a splendid opportunity to test your talent. Read the rules and send your drawing to the address below. тү. _ 9 RULES This contest open only to amateurs, 16 years old or more. Professional commercial artists and Federal students are not eligible. 1. Make drawing of girl 614 inches high, on paper 7 inches square. Draw only the gir), no lettering. 2, Use only pencil or pen. 3. We return no drawings. 4. Print your name, address, age, occupation on back of drawing. 5. All drawings must be received by Novem- ber 26th, 1937. Prizes will be awarded for drawings best in proportion and neatness by Federal Schools Faculty. FEDERAL SCHOOLS • INÇ Dept. 12067, Federal Schools Building, Minneapolis, Minnesota When Answering Advertisements Please Mention December Modern Mechanix 25

Page 26

Two Giant Industries AIR CONDITIONING ELECTRIC REFRIGERATION We supply trained men for America’s two fastest growing industries. If you can meet our re- quirements, we wlll train you in spare time at home for a good pay position as an Installation and Service Expert |n the Electric Refrigeration and Alr Conditloning fields. In addition we will give you ACTUAL Shop Practice when you grad- uate, and help you to qualify for profitable em- ployment with an exceptionally bright future. Can You Qualify? To be acceptable for enrollment you should be mechanically inclined, between ages of 18 and | 40, have falr education and be able to furnish WY character references. GET FREE BOOK Get amazing facts about nctual opportunities for amblitlous men in Air Conditioning and Electric Refrigeration. Our new Free Book describes these money-making op- portunities and tells about our low-cost, casy-pay plan of training, Send coupon below, or write for your copy today, stating age and which industry interests you most. No obligatlon. UTILITIES ENGINEERING INSTITUTE Estaptishes 400-410 N. Wells St., Dept. 2127 Chicago, lll. SEND THIS COUPON FOR FREE BOOK Utilities Engineering Institute, Dept. 2127 400-410 М. Wells St., Chicago, Ill. Please send me your Free Book telling how I can qualify for the big opportun!ties offered In Air Conditioning and Electric Refrigeration, I have marked whieh interests me most. Ll [0 AIR CONDITIONING ELECTRIC REFRIGERATION Name Address es- Jool of 100! Us A NIFTY GIFT For Boys from 7 to 70 A whole shop full of tools in one—for work on all metals, alloys, bone, resins, plastics, glass, stone, wood, etc, Uses ; 200 different accessories to 5 grind, drill, cut, carve, sand, saw, engrave, sharpen, clean, polish, etc. Saves hours of tedious hand work. Plugs in any socket AC or DC, 110 volts. STANDARD MODEL A sturdy little helpmate. Weighs 1 pound. 13,000 r.p.m. $10.75 postpaid, 3 Accessories Free. DE LUXE MODEL Fastest, most powerful tool of its type and weight, 12 ounces, 25,000 r.p.m. $18.50 postpaid, б Accessories Free. GET A DEMONSTRATION at your Hardware, Depurtment or Tool Dealer or order either Model on 10- Days, Money-Back Trial, Catalog Free. CRAFTSMAN'S PROJECT BOOK Easy working plans for making many in- teresting and unusual projects, 25e stamps or coin, Chicago Wheel & Mfg. Co., 1101 W. Montoe St., Dept. H, Chicago, 117. L| $10.75 Model О Project Boor, C Send C. О, D. E] Send Catalog O De Luse Model Name Address umbia University, cross. Be Sure to Re our Copy of PHOTO FACTS from your local news déaler—out October [5th Or send 25c in stamps or coin to 22 W. Putnam Ave., Greenwich, Conn. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 27

dmazing!.. MIDWESTS ELECTRIC ELECTRIC TOUCH BUTTON TUNING. (oy do) TOLLS YOUR TUNING 7. BES ; WAVE BANDS resonance. (You can also tune The famous Midwest factory-to-you plan, proven by 18 years of success, is just as exciting. 1% enables you to buy at wholesale prices . . . to save up to 50% . . . to make your radio dollar go twice as аг, . . and to pay as little as 50 cents a week on the Midwest Easy Pay Plan. EVEN MORE GLORIOUS TONE When you tune in a domestic or foreign program on this super 20-tube 6-wave band 12,000 - mile - range Motorized Midwest, you hear it with a new clarity, new depth and an intensity of feeling. Glorious, crystal-clear concert realism and brilliant foreign reception are now realities. Super power and 101 advanced features MIDWEST DEPT. HH-10, MIDWEST RADIO CORPO ATION... CINCINNATI, OHIO, U.S.A. Vd a of Quality Radios Since 1920 When Answering Advertisements Please Mention December Modern Mechanix LASH! Here's today’s biggest radio news—Midwest and only Midwest gives you a combination of Mystic Movie Dial, Traveling Coloray Eye, Phantom Hand and Motorized Tuningl radio... that's all... and FLASH!... your station comes in perfectly tuned, in one second . . . just like magic . . . at the exact center of | 0 TUBES | NEW LOW BASE PRICE CHASSIS Just touch a button on top of the Do not confuse Midwest "Instant'" Motorized Tuning with ordinary so-called *"Touch-Button' radios that require 3 to 5 times as long to tune...and on which you have to turn switches and controls. You don't even have to turn the Midwest on, or handle any controls . . „ it, does everything itself. SERVICE MEN; Join nation-wide Midwest service organization. Write for free details. PASTE COUPON ON Ie POSTCARD +. OR. IDWEST RADIO COR PORATION Dept. HH-10 Cincinnati, 0- Send me your new FREE catalog and complete details o your liberal 30-day FREE trial offer. (Special, offer end Orices prevail only a direct when dealing | S by hand whenever you desire.) enable you to bring in weak distant | foreign stations like "locals." Now | delight in American, Canadian, Police, Amateur, Airplane, ship broadcasts „ . . and finest Foreign programs. 30 Days FREE Trial In Your Home Act at once on this unusual factory-to- you offer. We send any Midwest radio you desire to your home. You useit 30 days, and compare it with other radios you have owned or heard. You are triply protected with One- Year Warranty, Monev-Back, and Foreign Reception Guarantees. Send for FREE 1938 Catalog RADI E OS User-Agents Make Бозу Extra Money. Chack[-]Horefor details [Check Here for 1938 BATTERY catalog : with factory 27

Page 28

Page 29

The tiny car has three speeds forward and one re- verse. Its construction features a steel frame sup- ported on four springs, the front ones being 18 inches long and the rear, 22 inches.. (The driver is four years old.) Abner А. Beyer. We think most readers will agree with us when we say that Beyer's midget racer is an unusually fine one. Жжжж Ап award of $3 was sent to Nicholas Stark, of New York, N. Y., for an interesting project photo and letter. Stark writes: Dear Editor: . I am enclosing a photo of my powered scooter, des Signed and constructed by myself. It is 40 inches long and driven by a 34-horsepower washing machine motor, The scooter is started by а good push and a speed of 25 m.p.h. is obtained. Low gas consumption makes the operating cost very reasonable. Nicholas Stark. We'll bet that reader Stark is much envied by the neighborhood boys when he rolls up with his powered scooter. It cer- tainly is & useful and pleasure-giving project. же Nicholas Stark with his home-built power scooter. Model locomotive fans will be interested in a letter and photo from Bart- lett Sissons, of Alberta, Canada, who was awarded a $3 prize. The letter reads: Midget racer fans will be quick to acknowledge that this speedster, built by Abner А. ever shown in MM pages. December, 1937 Beyer, is one of the finest The “driver” is four years old. This model locomotive, perfect replica of its Canadian National Railways prototype. built ‘by Bartlett Sissons, is a Dear Editor: I enclose a photo of a Canadian National locomotive model that I recently constructed. This model is run by a motor situated in the firebox and geared to the driving wheels, Your article on Midget Mike helped me very much in constructing this and other locomotive models. Bartlett Sissons. Sissons' model locomo- tive is а good looking job. Model railroaders who want to build a fascinating little locomotive should secure a copy of the latest “How To Build It" book and read the article on building Midget Mike. xe ` Unless builders of model airplanes powered by miniature gasoline engines unite in their efforts to combat threatening legislation, they may find themselves in the same predicament as the home- built aircraft fans—banned from flying their creations. Several states have already banned gas-powered models, one state passing a ridicu- lous law requiring the builder to hold a real air- plane pilot's license before he can launch his model! We strongly urge every airplane model builder to protest laws that would ban the flying of gas- powered models and request that you file your letter of protest with the editors of MM who will co-operate with aviation editors and organizations preparing to wage “war” on the proponents of legislation that would be detrimental to the hobby of flying gas-powered models. жш Although this year's boating season is well over, we know that many MM. boat fans will find a [Continued on page 31] 29

Page 30

AMAZINGLY EASY WAY TO GET INTO ELECTRICIT 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— OT 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 details of my ““pay-after-graduation plan” where many get my training first and start paying forit 5 months after they 6tart school and then have 18 months to complete their payments. LEARN BY DOING —IN 90 DAYS BY ACTUAL WORK —IN COYNE SHOPS J don't care if you don't know an armature from an air brake — E den S Aeg уон ГО! Соуде ешш " practical iearn-by colng x et lack of mone: 1 of my amasis D oney hold you back from getting all de- MANY EARN WHILE LEARNING Xf you need part-time work to help pay your living expenses we will give you the help of our employment department to assist you to get а part time job, as we have thousands of others. We give you a 12 weeks practical training in the great roaring shops of Coyne . . . on опе of the greatest outlays of electrical apparatus ever assembled ... rea] dynamos, engines, power plants, autos, switch-boards, transmitting stations «oe devel. Arines "ái € Conditioning and Electric Refrig« on...everything from doorbells to farm power and lighting ... full sized „ „ „Їп full operation every day! pe Hog DIESEL ENGINES AIR CONDITIONING ELECTRIC REFRIGERATION Additional instruction included їп these fast growing fields at no extra cost, GET THE FACTS Сотера shoa ds 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 earn expenses while training and how we assist our graduatesin the field, No obligation to you. So act at once. Just mail coupon. BIG FREE BOOK? 25:55; photo: з ап ling E bsorately F КЕЕ. complete MUR «X. . e А fu, COYNE ELECTRICAL SCHOOL sco S. PAULINA ST., Dept. 97-53, CHICAGO, ILL. qmm = ==» uu шы — a "m: Ju "uu лыр | Н, C. LEWIS, Pres, COYNE ELECTRICAL SCHOOL | Dept. 97-53, 500 S. Paulina St., Chicago, 11, Dear Мт, Jevis: Without, obligation send me dur big, free | abou talls "iPay-Tuition-After-Graduation Pas с т Name .cesereresccccccccccssccecssccsessces AGE Address, азе ка какала канака азакка каваная * | MEN— WOMEN— AGE 18 TO 50 Arthur R. Patterson (Former Gov't Examiner) Prinelpal, PATTERSON SCHOOL, 9215 Mercantile Bidg., Rochester. Send for FREE LIST Social Security Employes To Be Hired "Through Examination BE SUCCESSFUL Read Invention & Finance—it's your chance to make money. · Year subscription 60е entered upon promise to pay on receipt of first сору. Place your order by cutting out and mailing this advertisement. INVENTION & FINANCE MAGAZINE 80-H WALL ST., NEW YORK, N. Y. DRAW Anathing New Sight Correcting Course by noted Instructor starts you draw- Ing the firat day. Fast. You see your own mistakes. Starts begin- ners right. Excellent for advanced students. Figures, faces, inte- rlors, still life, EVERYTHING. Learn.im spare time. E} yo dni.) о b А SEND NO MONEY Thousands of courses sold. Satisfaction guaranteed or money 'omplete course wi eous fi , land. , SIGHT-CORRECTING ваен. ae deni За order amd рау postmen $1 plus postage. COURSE, COMPLETE ARTISTS & MODELS STUDIO, Dept. MM-12, Memphis, Tenn. STUDY AT HOME Legally trained men win high- er positions and bigger нис» cess in business and public life. They command Tespect, iw than arere P co norations are headed by men witb legal training. More Ability: More Prestige: More Money ‘We guide you step by step. You can train st home ї time. ee of LL. B. conferre: foen e graduaren in every Mpection of the United Stai ‘Ws ites. We j ial, including fourteen-volyme Law Library. к 2s Grma. Get my valuable 64-page biet "Training for Leadership’’ and ‘‘Evidence’’ book: в LaSalle Extension University, Dept. 12493-L, PAY RAISING BOOKS AVIATION, AUTOS,| Send Name, Address and 3 AIR CONDITION- Cent Stamp For Catalog ING, REFRIGERA-1 Describes helpful books on these and other TION, ELECTRIC- Ha subjects. Books to help you en our ITY, TELEVISION,| job; to Prepare for a better one: to make more money. Thousands of users boost RADIO, ETC. E! y them. Send 3 cent stamp wlth name and GOODHEART-WILLCOX CO., Dept. 19,2009 Michlgan Ave., Chicago FOLLOW THIS MAN Secret Service Operator No. 38 ів on the job! Running down dangerous Counterfeit Gang. Teile tale finger prints in murdered girl's room. The Confidential Report YQQ Operator No, 48 mado to his chief. Write for $t. Earn а Regular Monthly Sala! YOU can become a Finger Print Expert at home, re time, at amel] cost. Write forcon- Literatare will НЕЕ. Send for them NOW. Chicago Operator Neo 38 INSTITUTE OF APPLIED SCIENCE 1920 Sunnyside Ave. Dept. 2359, Chicago, tt. 30 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 31

Editor's Workbench Chips [Continued from page 29] TUAE Using plans that appear in the MM “How To Build 20 Boats” book, Ray Watt constructed this trim auxiliary sloop at a cost of only $40, including sails. Isn't she a beauty? photo and letter from Ray Watt, of St. Ignatius, Montana, to be of interest. Watt was awarded a $3 award and his letter reads: Dear Editor: Enclosed is a photo of “Bail-Out,” an auxiliary sloop built from plans of NOMAD in the MM boat book. It is a very seaworthy craft and exceeded my expecta- tions in every way. I built this boat in my spare time at a cost of $40, including sails. It is built of select yellow pine and is entirely home-made, even to the mast and boom. The only deviations from the original plans lie in the use of oak chines and a double bottom. Ray Watt. Watt’s trim looking craft certainly should pro- vide inspiration for you fellows who plan to build a boat this winter. Get a copy of “How To Build 20 Boats” and take your choice of the best lot of boat plans you ever cast your eyes on. a He oe Every reader of MM is invited to send in photos and letters describing completed workshop proj- ects. Although we prefer to use photos showing projects constructed from MM plans, we assure our readers that equal consideration will be given to other photos. Photos, upon being received at the MM office, are judged by the editors and the best photo re- ceived each month is awarded a prize of $5. All other photos used in the Workbench are awarded prizes of $3 each. The fact that a photo does not receive a prize one month does not mean that it will not be considered when the following month’s judging is conducted. In fact, the photos are judged collectively each month, the best of those on hand being considered each time. own a ROYAL PORTABLE ON YOUR OWN TERMS! You’ve ideas—ideas that are worth real money to you. Don’t waste them . . . Present them right to the right people— worked out in your spare time— typewritten. Easy! Even if you've never thought of typing—if you own a Royal Portable! For Royals are scientifically designed for everyone to use. With full-sized standard keyboard and such genuine office typewriter features as Royal's famous Touch Control, Finger Comfort Keys, Complete Dust Protection and many others to make writing easier! Only a few cents a day Get the facts! Try the Royal Portable in your own home free! And remember you can own a Royal on your own terms ... cash, or only a few cents a day. FREE! Carrying Case and Instant Typing Chart Handsome triple-purpose convert- ible Carrying Case; also a free Instant Typing Chart. Latest in- vention—it shows you, at a glance, how to type right. ROYAL TYPEWRITER COMPANY, Inc. » Dept. A-72, 2 Park Avenue, New York City, N. V. Please tell me now г can own—for only a few cents a day—a latest model, factory-new Royal Portable—complete with free Carrying Case and Instant Typing Chart. Name. Street City ——$— — —Siate. I already own a Typewriter, Serial No. —— 2 LL ————. Tell me how much you will allow on it as CASH payment on a new Roval Portable. M MM SEM UE TUAM MM А When Answering Advertisements Please Mention December Modern Mechanix 31

Page 32

MENS 9 ELECTRICITY © AUDELS HANDY BOOK OF ELECTRICITY $ HANDY For Engineers, Electricians, Students and allinter- ested in Electricity. A quick, simplified, ready SIZE ae reference, giving completeinstruction and practical information. Easy to understand. A reliable au^ thority and a handy helper that answers your questions. @ INSIDE TRADE INFORMATION ON The Rules and Laws of Electrice ity Maintenance of Machinery- A.C. and D. C. Motors--Armae ture Winding and Repair-Wir- ing Diagrams House Lighting ~ Power Wiring--Cable Splicing~ Meters~Batteries--Transformera * Elevators » Electric Cranes « Railways--Bells--Sign Flashers- Telephone~Ignition~Radio Prin- ciples-- Refrigeration Air Con» ditioning-OilBurers~Air Com- cg eee N edding, and many Modern Applications explained so you can understand. А 1340 PAGES To get thisassistance for yourself, simply 2600 ILLUS, — &llin and mail the FREE COUPON below. R'SHEERREESUEENRUSSENSHERERNEENRERREARRERERRREZERARS THEO. AUDEL & CO., 49 West 23rd Street, New York ,blease send me **Audels Handy Book of Practical Elec- tricity’? for free examination. if satisfactory, I will send H HL in 7 days, then $1 monthly antil $4 ia paid, Otherwise Н will return it, FINANCE YOUR TRAINING IF YOU ARE SHORT ОЕ MONEY Prepare for jobs in Radio Broadcast, Talking Pictures, ^4 Television by 12 weeks of practical shopworkinthe great Co е Radio Shops, on real RADIO and Sound equipment. You don’t need advanced education or experience. Free Employment Serv ice for life. Many earn while parning. Electric Refrigeration—Air Соп» ditioni: g included. MAIL COUPON TODAY for free book which tella you bow hundreds have become successful Radio Men after taking our training- H. C. LEWIS, Pros., COYNE ELECTRICAL & RADIO SCHOOL 500 S. Paulina Street, Dept. 67-2H Chicago, Ilinois Send Exec Radio Book and facts. Tell me about your **Pay-Tuitlon-After-Graduation”’ Plan, N. ADDRES: TOWN. сЕ. less cutters (C.O.D, or outside U. Make tongue and groove Shape mouldings, picture plaques, ete. joints frames, this shaper. table; stands 5%” high. Uses standard It has 8"x534" 5/16” hole cutters. Oilless hearings. motor runs it. (Cutters 55e each). Your fractional H, P. Describing cash prize contest and illustr. com- lete power tool line: Circ. S. ith ollles GE CATALOG Bearings $3; Drill P. à 3750; completely 2 equipped Lathes, $2 and $4.90 etc. Order today or send card for Catalog. J'& Н Metal Products бо. 8 Commercial St. Rochester, N- Y- Limitless projects can be given a professional finish yiu stec | $7,50 eacu РОЅТР Mos: 0 EACH POSTPAID Wo are never undersold. ae dT BOTH { ERA & PROJECTOR $ Compl t 50 сорла Everything to fake and show real 16 mm. movies at less cost than taking snapshots. CAMERA—Spring Motor drive—Automatic Release Button—Footage Indicator PROJECTOR — Quiet, smooth—and dickerless FREE — 50 foot capacity. No ad- diy built. Uson any 50 FOOT PRO- justments necessary. stendard 16 mm. film. TECTOR FILM PARAMOUNT MFG. CO., with each Dept. M-91 $13.50 COM- BOX 224, BACK BAY, BOSTON, MASS. BINATION. Write NOW for Big FREE Catalogue of Movie Sup- plies and Film Subjects. Waterproof Your Own Save up to Amazing new Seal-Seep method, any- опе сап use. Applied to inner] $100 to $150 masonry wall and floor surfaces; no digging. Guaranteed permanently effective. Agents write for unusual earnings opportunity. Details FREE. National Seal-Seep Co., Dept. 1216, Cincinnati, О. “RET SERVICE BOOK | FREE For 30 Days Reading - No Money Down—Actual Crime Cases— — . , ow Act Quick/—We will send you this stirring book on Crime Detection, Secret Service and Iden= tification Work for 30 days free reading. Send no money. If you decide to keep it, then send me only $1.00. If not, return it. WRITE TODAY. Liter- ature will be sent only to personsstating their age. | Т.С. Cooke, Dept. 2359, 1920 Sunnyside Ave., Chicago, lll. Automobile Racing Book (Eius) Nine chapters, 66 illustrations of dirt, midget, and championship cars and drivers, How to build cars and bodies; 14 plates working drawings. Ford V-8 front drive racer illustrated and described. Book answers questions on speeding up cars, balance, speed revs., sj h rules, specifleations, track records, ete, Postpaid $1.00; С. 0. D. $1.15. Order NOW! RAY F. KUNS, Dept. A-12 Madisonville, Cincinnati, Ohio Be modern! Enjoy quick, close shaves without blades, soap, brush or water. earn how to get this double-edge ly gs Electric Dry Shaver. Write quick! wa i) WITHOUT COST TO YOU! ^ APPRENTICES BIG PAY GOOD FUTURE 1f you are interested in working yourself into a fighiy paid positlon in Aviation under our Арргеп- tice-Plan— Write, immediately, amclosing stamp— MECHANIX UNIVERSAL AYIATION SERVICE CO. Strathmoor Station Dept. A Detroit. Mich. 32 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 33

116 Projects You Gan Build The 1937 Modern Mechanix Blueprint Booklet is America's best index to how-to-build projects for fhe home shop. It contains nearly 70 illustrations and lists more than 116 blueprints. SCORES OF VALUABLE BOOKS FOR YOUR SHOP LIBRARY ARE LISTED IN THE 1937 Blueprint Catalog—F RE E Send your name, address, and three-cent stamp to cover mailing cost for your: copy to Modern Mechanix Publishing Company Fawcett Building Greenwich, Conn. к out, ete. Cheaper buying shoe-leather. cradled on low-pressure ba: е 2 models: Karl-Pac Gilustrated) or &uto Glide (without carrier.) H. P. о: lo H. P. Cushman engine. Starter, clutch, brake, jf ight. etc, See your dealer or write FREE BOO K ! for free illustrated book with complete detalls! E à DEALERS: Write today for Special Offer! THE CUSHMAN MOTOR WORKS, $125 Гері. B-12, Lincoln, Nebr. Pa 60 POWER TELESCOPE $2.19 VARIABLE EYEPIECE. 20X—20X—60X NEW! Three telescopes In one. 3 different mage nlfications. 20 power for ultra-bright images saith 40 and 60 ower Тог eatre ong range. Guaranteed to bring dis! » objects, people, sports evente, ae ES moon, вёаге, etc. "= 60 times ва close. Most power- | made for anywhere т "m. rses. mount. Directions Included for ueing as а compound 4 lens mleroscope. American made. We ра the postage. Only $2.10. Catalog of Microscopes, Binoculars, etc. FREE on request. BROWNSCOPE CO., Dept. 712, 234 Fifth Ave, New York, М. Y Business Proposition Resilvering Mirrors, REFINISHING PLATED Articles, Autoparts, reflec- tors, tableware. Making Chipped Glass Name Plates, Signs. Experience unnecessary. Write SPRINKLE, Plater., 855, Marion, Indiana, 110 volt, 60 induction This offer positively will not be repeated next month. A. B. C. SPECIALTY CO. IRON MOUNTAIN, MICH. When Answering Advertisements Please Mention December Modern. Mechanix ENGINEERING TRIUMPH GILLETTE'S AMAZING 1-PIECE RAZOR Blades =) The Gillette TWIST di Sheraton closed’ C INTRODUCTORY OFFER NOTHER sensational Gillette manufac- turing triumph! Today you can buy, for just 986, a genuine 1-piece Gillette Razor —the Sheraton—in an attractive traveling case with 5 Gillette Blades! Until now, we have never been able to manufacture a razor of this type to sell for less than $4. Output is limited. Millions will want one. You may have to ask your dealer to get yours on special order. GILLETTE SAFETY RAZOR CO., BOSTON, MASS. Gillette RAZORS ano BLADES 33

Page 34

ars Fun to Discover Scientific Secrets with the New GILBERT CHEMISTRY SET New Gilbert Desk Type ` Laborator. "у Outfit —The latest triumph of the famous Gilbert Hall of Science. 5 feet of metal and wood shelf room and test-tube racks] mounted on sturdy wooden table. 76 chem} icals and pieces of apparatus including scales. Puts 500 fascinating experiments at your finger tips. $9.95. Other Gilbert Chem istry Sets $1.00 to $19.50, See them at youi nearest toy store. Up-to-the-minute em by noted Yale professors comes with cach set Boys, exciting days are in store for you when you own a Gilbert Chemistry Set. Think of the thrill of making strange chemicals change colors, writing mes- sages in fire ink, making your own paints, bleaching flowers and performing hun- dreds of other dazzling tricks. More boys have won fame and big awards with Gilbert Chemistry Sets than any other chemistry sets made. One boy de- veloped a candle that burns with a blue flame. Another boy discovered a way to trick for catching a sneak thief. You, too; can perform such wonders, but first be sure to get a chemistry set with the name “Gilbert” stamped on the box, : $200.00 Annual Awards To the boy doing what, in my opinion, is the most important research in Chemistry or Micro-Chemise try in 1938, I will award $100.00 in cash. To the ten boys doing the next most important research, I will award $10.00 each. Applicants must not be over 17 years old and must send me full descrip: tion of their experiments by June 1st, 1938. write messages in invisible ink on his A. C. Gilbert, Inventor of Erector and! arm. A third boy worked out a chemical Founder of the Gilbert Hall of Sciencel POLAROID Jr.— the Invention That Shows Nature's Wonders in Full Colors The new Gilbert Micro-Chemistry; х Sets enable you to see the mysteries of chemistry and Nature 200 times larger than they appear to the naked eye. The only sets of their kind with Polaroid Jr.-equipped microscope —, bringing you sights far beyon: the, power of ordinary microscopes, Sugar, crystals look like an array of brilliane jewels. Layers of cellophane take on weirdandfantastictones.Starch grains appear as luminous colored crosses, Gilbert Micro-Chemistry Set No. 7, complete with 38 fascinating pieces ofapparatusandbigillustrated manual, $5.00. Other Micro-Chemistry Sets from $2.50. Sugar crystals—as Sugar crystals—as seen thru ordinary seen го a Gilbert Microscope. Polaroid Jr.-equip- ped Microscope. rt nn rent станне eer en e ae nena --—— q EA CHEMICAL WEATHER FLAG Showsyou whethereachdaywillberainyorclear. Free—withmammothcolor . boster showing the new Gilbert Chemistry Sets, if you mail coupon at once Y Mail this Coupon — or 1¢ Post Card iM *. A. C. Gilbert, President IGilbert Hall of Science i Room 157, New Haven, Conn; 1 Count 7 ime in on your big free offer. Send i weather flag and mammoth poster. City....... er er ee a oo ee eee M M e I MMi 1 1 Н 1 ! Д ’ ‚ Li t ! . J Name. ceocccsccscccccccceccscversceess Streets sccccccerscccccccsscccccevesver bow ene cen een M 34 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 35

О e A em MEGHAN XG W. Н. FAWCETT, Publisher Advance Showing —1938 CARS Left: Plymouth for 1938 offers its tenth anniversary "Jubilee" model, featuring faster steering, easier handling and continuing reliability. The hood front has been stiffened considerably, and access to the én- gine is had through a half-section cover as pictured. Note length of engine compartment. ose. x ar tien ЕЛ а gu oem PLYMOUTH SIX Right: The safety style instrument panel of the 1938 Plymouth, with contzols recessed for pro- tection of passengers. All the instruments are grouped in the center of the board, for quick and easy observation by the driver. This photo also shows the new pistol-grip handbrake lever under the cowl. Below: the four-door sedan has broad, sweeping fenders, large wind- shield and unobstructed vision in all directions. N THIS page and the four follow- ing MopERN MECHANIX presents a condensed preview of next year's auto- mobiles. The me- chanical improve- ments incorporated in these cars are reflected in greater safety and com- fort and increased convenience and [Continued on page 120] OS dole ice 35

Page 36

Driving effort is greatly reduced, and control over the car is increased, by the new ''Tiptoe-Matic' clutch intro- duced in the 1938 Chevrolets. The makers claim that 25% less effort is requited to operate this clutch than in the 1937 model. The mechanism needs no lubrication throughout the life of the car. А new type of hand brake is also a feature. This has a hinged top, and is easy and positive in operation. Chevrolet remains а six-cylinder саг. the valve-in-head engine being brought up-to-date with many small improve- ments. In the Master series fully-en- closed knee-action is also retained. Unusually roomy interiors give the new Chevrolets increased comfort and utility. Photo at left shows the un- usually capacious trunk, which also contains the spare tire. Coil spring rear suspension is an ex- clusive Buick feature for 1938. Com- bined with airplane type shock absorbers, this provides greatly improved riding and steering qualities. -Phcto below shows spring and shock absorber hook- up on right rear wheel of Buick chassis. Size and thickness of spring may be judged by comparison with tire. ROLET This is the master deluxe coach of the Chevrolet 1938 line. The new styling is especially evident in radiator and hood. No-draft ventilation, all- steel bodies and safety glass continue as standard features. Я Above: Buick’s self-shifting transmission has the control arm оп the steering post under the wheel at the right. Photo shows the completely cleared driver's compart- ment. Hand brake is under cowl at extreme left. Left photo: The Buick hood lifts from the molding line, providing for quick and convenient "light" service. Hood side panels are stationary, lending strength to the entire front end sheet metal assembly. Radiator grilles are die-cast.

Page 37

A cutaway view of Hudson’s powerful duo-automatic hydraulic braking system with the “double safety” feature of an emergency mechanical brake linkage operating from the same foot pedal. This feature enables the driver to re- tain control over the car even after the hydraulic system has been dis- connected, by continuing to press on the pedal until the emergency ` rotary-equalized mechanical brakes take hold. The complete Hudson line consists of an eight-cylinder car made on both 129 and 122- inch wheelbases, a six оп 122-inch wheelbase, and the Hudson Ter- raplane on a 117-inch wheelbase. PONTIAC be seen. hood grille of the new Pontiac. Above—-The interior of the 1938 Pontiac. safety-shift remote control gear lever is shown directly below the deluxe type steering wheel. In- strument panel with accessory electric clock can Right—The Silver Streak radiator and No other style motif has been so characteristic of Pontiac since its introduction four years ago. Note the parking lights integral with the headlamps. The 1938 Hudson auto- matic shift includes an automatic circuit breaker switch which causes gear shifting to take place at the proper instant when the clutch is disengaged. The Left—-Its steering control lever located conveniently near the rim of the steering wheel, affording finger tip control, Nash’s new vacuum gear-shifting system is shown here in diagrammatic detail. Above—The instrument panel of the new Nash. The ait conditioning unit is shown just below the gear shift lever. This device supplies an abundance of warmed, conditioned air for winter driving. 37

Page 38

Page 39

Successor to the Austin is the new American Bantam, selling at prices from $75 to $125 below any other car in the low-price field. Shown at right is the 1938 Bantam “60” coupe, powered by a 4-cylinder, 20 h. p. motor suspended on live rubber. Performance claims in- clude speeds of 60 m. p. h., 60 miles to the gallon of gas and an operating cost of J4-cent per mile. In addition to the coupe, the manufacturers announce a complete series of “60” models. os att py. "ont I The new Hupmobile series includes two models, a six and eight. powered by an L-head engine. Both models provide greater body width and length. A distinctive radiator grille design gives both models a dynamic head-on appearance. Radiator decoration serves as handle to permit access to motor. Headlight: are built into the hood. Below—The new Willys Sedan for 1938 fea- tures a patented all-steel body and top, 178- inch overall length, safety type duo-servo brakes, improved steering and safety glass. The power plant is a Willys-built 4-cylinder engine providing economical operation up to 35 miles to the gallon of gas. Two models, a 5-passenger sedan and 3-passenger coupe. are available in a wide range of colors. WILLYS Below—Al1 four models of the 1938 Packard in- corporate scores of new details. One novel fea- ture is the expulsion of engine heat through lou- vres located under the front fender skirts. The outstanding feature of the new “Junior” series is a revolutionary type of rear spring suspension.

Page 40

This 36-foot racing car is being built for Captain George Eyston, of England, who hopes to attain a 400-m.p.h. speed with it. When completed, the racer will have eight wheels. Old Railway Thrills Tourists OURISTS visiting Cincinnati, Ohio, are thrilled by a ride on the local Mt. Adams Plane Railway, which was erected in 1877 to carry street cars up a 980-foot incline. Only the demand of sight-seers has saved the novel railway from being abandoned in the march of progress, over two million persons using the railway annually. The lifts of the old railway are drawn by four cables and operate in balance, one ascending while the other descends. Street cars using the lifts are kept on an even keel while traveling the 28.995 grade. Street cars carrying tourists are the principal users of this old plane railway in Cincinnati, Ohio. The cable lifts carry the cars up a 980-foot incline featuring a grade of 28.9%. 40 Mammoth Racing Auto Equipped With 8 Wheels THIRTY-SIX-FOOT streamlined rac- ing car being constructed at Tifton, En- gland, is equipped with eight wheels, four of which are needed to steer the car effec- tively at high speeds. The giant racer will . be used by Capt. George Eyston in an attempt to better the present speed record of 301 m.p.h., which is held by Sir Maleolm Camp- bell, noted English sportsman. Powered by two engines of 3,000 horse- power each, the new racer is expected to attain a speed of 400 m.p.h. according to Captain Eyston, who will make the record- breaking attempt at Salt Lake City, Utah. The racer features hand-made tires designed to withstand the tremendous heat resulting from speeding over the hard-packed sand of the famous Utah racecourse. Boys Turn Bike Into Chimes For the entertainment of several local girls, these English schoolboys are playing a tune on the novel chimes and stringed instrument they cleverly constructed from old bicycle tubing. OYS at Weoley Castle School in Bir- mingham, England, have developed a novel use for old bicycles. Sawing the old bicycle tubing to various lengths and string- ing the cut sections on wires hung on a home- built mounting, the boys have created musi- cal chimes featuring a full complement of notes, enabling tunes to be played. Modern Mechanix

Page 41

Ihree-Wheeled Biplane Has Simplified Controls TWO-SEATER biplane, fea- turing simplified automobile- iype controls that are said to enable student pilots to learn fly- ing in half the time ordinarily required, has been developed by Joseph Gwinn, Jr, of Buffalo, N. Y. The plane is equipped with a tricycle landing gear designed to insure smoother and easier land- ings for the amateur pilot. The “aircar,” as the Gwinn air- plane is called, has a wingspan of 24 feet and an overall length of 16 feet. Powered by a Pobjoy Niagara II engine of 90-horsepower, the plane has a top speed of 120 m.p.h. The gasoline fuel supply is governed by a foot accelerator. "Decelometer" Tests. Brakes When placed on the floor of an auto, a new “decelometer” de- vice (circle) invented by R. J. Alden, flashes a green light if brakes stop car within safe limits, and a red light otherwise. А “DECELOMETER,” an instrument for testing the efficiency of an automobile's brakes, has been invented by R. J. Alden, of New York. The device, which is placed on the floor of the car being tested, operates on the scientific principle of the release of kinetic energy built up by acceleration. A mercury switch mechanism causes the de- celometer to flash a green light if the car can stop within safe limits, while a red light flashes if the brakes are inefficient. December, 1937 The Gwinn “aircar,” a two-seater biplane (top), is equipped with a tricycle landing gear to insure safe landings. Lower photo shows the simplified control wheel that governs turn- ing, ascent and descent. Note the auto-type foot accelerator. Van Carries 12-Room Load APABLE of carrying enough furniture to outfit a twelve-room house, a stream- lined tractor-trailer van operated by a Camden, N. J., firm is 38 feet, 10 inches long and weighs 16,270 pounds. The exterior is made of steel, the interior being completely padded to protect the furniture. The van fea- tures a fire-blue finish, trimmed with gold leaf bands on the sides of the body. Claimed io be the first streamlined tractor-trailer ever built in America, this furniture van is 38 feet, 10 inches long. 41

Page 42

+ i = A swinging boom (above) enables the cameraman to secure an action “shot” of soldiers marching from a trench. Left—Even movie “wars are hell" agree actors John King and “Slim” Summerville, warming their hands between scenes of the photoplay “The Road Back." URSTING bombs failed to stop scores of German soldiers charging across the scarred battlefield under cover of night. The ground was rent by machine-gun bullets. Soldiers dropped hopelessly in barbwire en- tanglements. It was the World War all over again for many American Legion men and ex-German soldiers acting as extras during the filming of The Road Back. Every exploding shell and spattering of machine gun fire brought back memories of war’s deadliness. But this was a movie war—nobody was being killed! Hollywood’s explosive experts, through years of experience, have developed tricks that make acting in a movie war safer than cross- ing a busy highway. The script called for a night scene in the 42 ү trenches іп November, 1918, shortly before the Armistice was signed. It was bitter cold in France then. Universal Studio's special effects department had little difficulty obtain- ing this impression, as the spring nights, when the battle sequences were shot, were extremely cold for California. 'The air was frosty and smudge pots blazed in orange groves nearby. But there was no snow such as blew over the Western Front in Novem- ber, 1918. То accomplish this desired effect studio workmen simply sprayed white paint over the ground. Several acres on the studio's back lot was marked off for the battlefield. Official U. S. Signal Corps photos were scanned in order to get authentic detail into the battlefield set. A huge sky drop was built in the background, across the width of the battlefield. The sky drop consisted of a wooden scaffolding, some forty feet high, from which a great canvas curtain was hung. Painters were busy for several days spraying on "clouds." This gave

Page 43

by Earl Theisen No expense or detail is spared to make battle scenes realistic. the effect that the war ground's horizon was several miles away. Twelve pieces of digging equipment—tractors, Scrapers, and steam shovels, were required to dig trenches, grade the battlefield and to give it that shot-to-pieces appearance. Each day, after the night war episodes were shot, workmen would dig up the ground and sprinkle it with water to make the mire deep for the coming night. Realism of the first order. Real war is costly. So is a movie war! Thou- sands of rounds of blank ammunition for the 8 mm Mauser rifles were fired. One thousand pounds of black powder, five hundred pounds of dynamite, and 2,000 detonating caps went up in smoke for the combat scenes. Four hun- dred parachute-flares and seven hundred night flares were consumed during night film warfare. Workers prepare a shell-blasted farmhouse (center right) which will collapse in a later scene, while explosive experts (right) prepare a smoke bomb to provide thrilling action for the same scene. Few persons could tell whether this is - a real or staged war scene, so real istic does it ap pear to the camera

Page 44

Page 45

SHELL CRATER LOOSE MIXTURE OF EARTH AND CORK WIRE TO CONTROL a N NM EARTH PACKED У x Є SENKY БЕУ S ОМУ E MANS \ NN N SRS ANA The method used to prepare ground to get the effect of a shell striking and exploding, ing a gaping shell crater, is sketched above. The crater is dug in hard earth, the sides of the hole being tightly packed. Next, a measured powder charge is planted in the crater and covered with a mixture of eatth and cork. wire connects the powder charge to the explosive expert's control board located directly behind the scenes. In filming “The Road Back," the script called for snow flurries such as blew over the Western Front on Armistice Day, 1918, so studio workers sprayed white paint over the ground and trenches to create the proper background effect. used, which were stuffed with sawdust. The effects of bullets striking are obtained by two different methods. The usual system is to fire away with the rifle or machine- gun at the top of an entrenchment or building while the camera is safely located at one side filming the hits. Special care must be taken that bullets do.not ricochet. This stunt is used when actors аге not in the scene. To get the effect of bullets striking near players in trenches, tiny powder charges are embedded in the dust. These explosives a bullet biting the dust. The action of ma- have about the same power as toy torpedoes youngsters throw on the Fourth of July. In fact some explosives men have used torpedoes for this effect. A thin wire is attached to each charge and to a control board. As a man presses the control board buttons the small explosives go off, giving the effect of December, 1937 chine-gun bullets striking can be had by firing a series of these minute explosives in a row, all within a few seconds. A new trick was used in The Road Back to get the realization of a French bullet crash- ing a mirror in front of "Slim" Summerville, [Continued on page 122] 45

Page 46

The driver of the novel auto has an un- restricted view ahead and to all sides. Conveniently entered through a door at its front end, as shown above, this “teardrop” three-wheeled auto seats four. Campbell Sets Boat Record N A TEST that thrilled the crowds lining the shore of Lake Maggiore at Locarno, Switzerland, Sir Malcolm Campbell, famous English racer, established а new world's speedboat record of 129.4164 m.p.h. The previous record of 124.86 m.p.h. was held by Gar Wood, noted American speegbqat de- signer and pilot. Sir Malcolm established the new record with his specially designed “Bluebird” speed- boat. In creating the record, the “Bluebird” covered the outward run of the measured mile course in 27.6 seconds, covering the mile at a 134.43 m.p.h. speed. Sir Malcolm now holds both land and sea speed records. Skimming over the water at an average speed of 129.4164 m.p.h. in this specially designed “Bluebird” speedboat, Sir Malcolm Campbell, famous English sportsman, set new record. 46 Three-Wheeled Car Goes 50 Miles on Gallon of Gas OWERED by a four-cylinder motorcycle engine, a streamlined three-wheeled automobile constructed by R. H. Griffin, of San Diego, Calif., has a top speed of 60 m.p.h. The novel auto carries four persons and is said to average 50 miles per gallon of gasoline while traveling at a speed of 40 m.p.h. The ‘“tear-drop” shaped auto cost $450 to build and weighs 975 pounds. It is 14 feet, 4 inches long and of standard tread, with a frame of steam-bent oak and axles made of iron-bark wood imported from Australia. One of the outstanding features of the vehicle is the use of rubber straps in place of metal springs, involving a weight saving of more than 38 pounds. The body design of the car, which provides an entrance door at the front end, affords full vision for the driver. A wind tunnel, running from front to rear, cools the engine and air conditions the body interior. Builds Novel Model Exhibit Controlled by a single small motor, this model exhibit oper- ates for five minute periods during which the landscape shows the rising and setting of the sun, trains speed along, boats pass each other on a lake, rcosters crow, airplanes fly, etc. MODEL exhibit featuring an electric landscape that shows the setting of the sun, the rising of the moon, and the rising sun of a new day, has been constructed by a Portage, Wis., model builder. The land- scape, which contains over one hundred small lights, required a year and a half to build. The exhibit operates entirely by itself for five minutes during which a breeze blows across a lake; roosters crow; a church bell rings; a train winds its way through a vil- lage, etc. All electrical connections, sound effects, etc., are operated by a small motor. - Modern Mechanix

Page 47

Seaplane Base Design Features "Even-Keel" Cradle DESIGN for a tidewater seaplane terminal in- volving constructional de- tails that would enable all types of amphibians and seaplanes to be handled on an even keel during all stages of raising and lower- ing from the water has been conceived by John J. Curry, of New York. The design is such that very little valuable waterfront property is needed for installation. Seaplanes using the proposed terminal would approach the device, taxiing to a posi- tion over a submerged cradle. А motor mechanism would then cause the “even-keel” cradle to travel up an inclined ramp, carrying the aircraft out of the water and up to a plat- form on which passengers could alight. Hobby + ч Builds Tiny Bikes As Building the world's smallest bicycles is the unique hobby of A. G. Tabb, an Englishman, who is shown with his daugh- ter while riding a tandem bike that is only 17 inches high. UILDING the world's smallest bicycles is the honor claimed by A. G. Tabb, of Kidderminster, England. He has constructed several of the miniature cycles, the latest being 17 inches long and nine inches high. Many of the novel bicycles are two-seaters. December, 1937 Seaplanes using this tidewater terminal conceived by John J. Curry of New York City, would be carried from the water on a special cradle designed to hold the plane level. College Teaches Yachting XTRA-CURRICULAR courses in all phases of yachting are offered to stu- dents at Massachusetts Institute of Tech- nology in Cambridge, Mass. Needless to state, the courses have become one of the most popular of student activities. The college. boasts a fleet of 38 sailing dinghies, the largest collegiate yacht fleet in the world. The dinghies were especially de- signed by Professor George Owen, of the M. I. T. department of Naval and Marine Architecture. The efficiency of the dinghies and their crews is attested by the fact that the Institute holds the Intercollegiate Dinghy : Championship. . The dinghies are each 12% feet long and 5 feet wide, with overhanging bow and stern. A feature of the design is provision for two masts, enabling the craft to be rigged as sloops or catboats. The dock of the sailing pavillion maintained by Massachusetts Institute of Technology is always crowded with students eagerly awaiting their turn to sail one of the college’s dinghies. 47

Page 48

The speed. of an iceboat de- pends to a large extent upon its construction. Hollow oval- shaped or streamlined masts and tear-drop runner planks should be incorporated in the design of a speed craft. AILING four times faster than the wind is a remarkable phenomenon alien to every other wind-driven vehicle but iceboats. Early craft, that only doubled the velocity of the wind, established the time-honored question, “Why do icecraft outpace the wind?” Improvements based on scientific develop- ment increased the speed ratio to 3 to 1. Today,: ultra-modern ice-fliers achieve the The cockpits of modern ice- boats are designed not only for speed but for comfort as well. The two-place ice- boat shown below possesses both of these vital features. 4 to 1 ratio with greater frequency than the question is answered. i Unless wind and ice conditions are favora- ble, relatively high speeds on ice are not ob- tainable. On smooth ice, а 10-mile breeze will propel a light-weather craft 40-miles an hour. Let's see what causes this phenomenon. To avoid complicated problems in physics and mathematics, a simple factor in aeronau- ties will illustrate the forces that contribute to iceboat speed. The wing of an airplane appropriately compares to sails. The curved top surface of an airplane wing has the sole purpose of creating suction, or lifting power, to hold the ship aloft. The greater the curva- ture, the greater the lifting power, while flying. It may be surprising to know that two-thirds of the total lift of the wings comes from top-surface suction and only one-third from the pressure brought to bear against the tilted bottom surface by flying speed. Similar factors are manifest in iceboat sailing. As the wind strikes the sail, it bellies. .The curvature resulting on the lee side cor- responds to that of the airplane wing’s upper side. An efficient non-porous sail protects a vacuum behind it, while the wind is blow- ing. The presence of the vacuum can be de- termined by holding a match close behind the Modern Mechanix

Page 49

ceboats Qua druple The Wind's Speed! DIR Econ) OF 3 277 Оа LIFT а PRESSURE =173 OF LIFT FLYING Mín. The iceboat sail compares with the lifting surface of an airplane wing, as shown in the above detail. Like ‘the airplane top wing surface, two-thirds of the lift or pull on the sail is developed on the bellied side. sail, even while the craft is standing still, with sail filled. For lack of air, the match willgo out. Hold another match farther from Һе sail, protected by the wind, and the flame will be drawn outward by the suction. While under way, the vacuum causes a terrifie suction behind the sail with a pull greater than the wind's actual driving power. That pull provides two-thirds of the speed of average craft and three-fourths of that of racers. АП this is predicated on the fastest point of sailing, which is 150 degrees or 13% points off the wind. Beam winds would seem to cause or create lateral suction or “sidepull.” But resistance of the runners prevents lee- way and directs the pull forward. Because December, 1937 the vacuum is greatest in quartering winds, sailing down-wind limits momentum to the wind's speed. Speed consistency is impos- sible in puffy winds; rough ice and heavy snow are also speed deterrents. Another explanation is that an iceboat is like a wedge between the resistance of the runners and the lateral pressure of the wind. Between these opposing forces, the craft escapes the pressure by seeking the line of least resistance, which is forward. Because ice resistance is negligible, the craft, like a bar of soap wedged in one's wet hand, shoots ahead with incredible speed. Again, an iceboat creates its own wind as it moves along. Its momentum sends a rush of air back to the sails to enhance driving power. Puffy winds, especially, furnish an example of this. As the craft gets under way, [Continued on page 120] 49

Page 50

Ninety persons committed suicide by jumping from the Arroyo Seco Bridge (top) in Pasadena, Calif., fore authorities erected a 7-foot wire fence around railing. Lower photo shows close-up of the fence and a wire rail-end guard. Lifeguards Use Surfboards IFEGUARDS at Los Angeles, Calif., have been equipped with new surfboards and new inhalator machines to facilitate their task of patroling five miles of beach. The surf- boards are constructed like airplane wings, being of hollow construction, and are said to be much faster than the old type lifeboats. Because they are faster than lifeboats, lifeguards at Los Angeles beaches now use surfboards to reach swimmers in dis- trese. Open boxes contain latest type of inhalator machines. 50 | j WIRE FENCE BALKS BRIDGE JUMPERS. OSTING $20,000, a 22-ton woven wire fence has been eed on posts along the railing of the Arroyo Seco Bridge in Pasadena, Calif., in an attempt to balk the suicide attempts of despondent persons. The fence stands seven feet high and is topped with bobbed wire. The bridge is a beautiful, gracefully- curved steel and concrete arch located in a particularly scenic location of Pasadena and from its highest span it is a sheer drop of 150 feet to the arroyo below. Since the bridge was built, ninety persons have ended their lives by jumping froin it. Citizens of Pasadena became annoyed when the bridge became known as “Sui- cide Bridge” and local authorities, seeking to remove the stigma, raised funds for the construction of the fence. Policemen sta- tioned on the bridge will now be able to catch any persons contemplating a suicide jump before they have time to clamber over the seven-foot fence. Tots Study "Stop-Go" Lights Policemen in Boston, Mass., "e miniature traffic signal towers to teach city's school children meaning of the various colored lights. Current is provided by means of a long cable. HE Police Department of Boston, Mass., is teaching the city's school children to observe traffic lights when crossing streets through use of a miniature, portable signal unit. Standing about four feet high, the signal unit features the customary red, yel- low, and green lights. During school hours, groups of children are taken to a street intersection near their school, the tiny traffic tower is set up, and a policeman explains the meaning of the different colored lights. Current for the portable signal unit is derived by means of a long cable. attachment. Modern Mechanix

Page 51

Amateur Photo Fan Snaps Picture Of Rare Lightning HILE taking pictures during a storm, an amateur photographer at Lake Mag- giore, Switzerland, was fortunate enough to secure a photo of a spiral of glaring light which revolved rapidly on its way to the ground. Lightning of this type is very rare and the amateur's photo is said to be the first of its kind ever taken. The Swiss Meteorology Bureau explained the phenomenon as resulting from some highly inflammable compound in the air dur- ing the storm which, ignited and surrounded by electrical discharges, made its way to the earth in the weird spiral form. Unusually quiet in operation, this rubber-tired electric lawn mower need only be guided over a lawn, since it is moti- vated by a compact one-quarter horsepower geared motor. EQUIRING only that the user guide it, a new electric lawn mower supplies its own motivation by means of a two-wheel drive powered by a gear and head motor of one-quarter horsepower. The mower travels at a two-and-one-half-mile per hour speed and is said to be capable of climbing an embankment of 35 degrees. Ап automatic control switch on the handgrip governs the 110-volt current that runs the motor. December, 1937 This unusual photograph, taken by an amateur photographer during a thunder storm at Lake Maggiore, Switzerland, shows the glaring light of spiral lightning, a very rare phenomenon. "Alignoscope" Aids Motorists LACED before the radiator of an auto, an *alignoscope" mirror device, invented by A. J. Mathieu, of Miami, Florida, indicates whether or not the front wheels are in proper alignment. The mirrors are set at an angle that reflects the wheels so they appear to be side by side. A line drawn through the tread center of each tire thus enables the auto owner to determine proper alignment. The mirrors can be set at different angles in a few seconds by a simple adjustment. Reflecting the front wheels of an auto so they appear to be close together, a new "alignoscope" enables mechanics to check alignment. Note wheel reflection in device's mirrors. 51

Page 52

Page 53

by i Maxwell R. Grant Withasingle scoop, man-made monstersequalthe .. work of hundreds of strong теп. - cement quarry. Its boom is slightly more than half a block long! Even if you have the half-million dollars to buy one of these big draglines, the chances are you won't want to buy it outright. There aren't many jobs big enough to keep this voracious machine busy long. Even the government usually rents one, for interest alone on the investment amounts to more than eighty dollars daily. Then, it costs a lot to get it on the job. When one of the big machines was shipped out to the All- Ameri- can Canal job in. California, it took eighteen freight cars to hold its dismantled parts. One of the weirdest sights imaginable is to see one of these huge diggers actually walk. December, 1937 Picking up an auto is child's play for the bucket of a drag- line used to make the All-American Canal (circle). Top—'The bucket "on the move.” Right—Control cabin of huge dragline. 53

Page 54

This dragline scoops up enough dirt in one "bite" to fill a waiting truck to overflowing. Note men at work in pit. The giant machine, with mighty rumbles and groans, arches the eccentric cams on its two sides, raises itself on its huge flat-footed shoes, and hunches forward, seven feet àt a step. Then the eigbteen-ton shoes lift and move forward ready for another step. The machine would make no speed records—its average gait is about a fifth of a mile per hour; yet it can wheel sharply, turn at right angles, or sidestep like some huge, awkward duck. Steering is just like backing a trailer. Point the boom the opposite way from the direction you want to go. Marshes, sand hills, mud flats, don't make any difference to this fan- tastic creature. Despite its million pounds of weight, it can walk over any ground that will 54 'This queer looking machine picks up dragline bucket loads at its left end (above) and deposits dirt at its right end, more than one hundred and seventy-five feet away. support a man. Its tread is light because its giant shoes, seven feet wide and forty- four feet long, spread this weight over an area half as large as an ordinary bungalow. When one was delivered for work on the Florida ship сапа], it was assembled at the station; it then "tramped" eight miles overland to the job, saving an immense amount of trucking expense and labor. The cab, which from the front looks much like a ferryboat, is a nest of giant motors—a big five-cylinder Diesel, the main power plant; a couple of big 100-horsepower elec- tries, which swivel the dragline on its base; and a battery of smaller motors that pump oil, keep water circulating, clean the air for the intake, and generate power for the lights—for on a big job they don't stop at night. Powerful floodlights bathe the exca- vation with their brilliance. Weather doesn't matter, either. The operator is snug behind his glass windows and it's warm by the big purring Diesels. Not even a desert sand- storm halts operations on the All-American Canal job; the machines are equipped with special air cleaners that take out grit that would score cylinder walls. One man doesn't operate one of these giants alone—he has an oiler.and several "pit men" to help. Certain parts of the machine have to be oiled every two hours, others every four, so the oiler has a continuous round of duty. On big parts like the cams which cperate the walking shoes, he сап smear heavy grease with a paddle. Other bearings take a good grade of lubricating oil. Modern Mechanix

Page 55

When the boom dips into a deep hole, the operator is so far above his work that dis- torted perspective makes distances deceptive. Pit men below wigwag where to drop the bucket, using a private sign language of their own derenan, Now and then the oiler must go up the nar- row cat-walk along the boom and lubricate the sheaf of pulleys at the end. It takes nerve to creep along the latticed frame in a stiff wind while the big machine monotonously weaves back and forth. As you look down, things on the ground seem small, for you are as high as a ten-story building. Objects blur before your eyes as you swing along on the boom at forty miles an hour. Up the center of the latticed boom, the cable races along, first in one direction, then the other. It is almost as thick as your wrist, a one and three-eighths inch bundle of twisted strands of steel, for it must stand a terrific pull when the One of the biggest draglines in the world (above) at work in an Iowa coal mine. machine reaches into the cut, strips over- burden away, gouges out a load, and swings it back out of the way. One bucket load represents work of hundreds of men. Regardless of the job. there is a dragline fitted for the work. Because of its big flat feet, this medium-sized dragline (right) can safely "walk" back and forth over the mud without fear of sticking as it scoops away at its job on the banks of the Columbia River, helping to. con- struct Bonneville Dam in the state of Oregon. December, 1937 operator gouges the twelve-yard bucket into hard, rocky formations. When he lets go, down it plunges, 154 feet a minute. The “pit man” waves his hand; the boom whips like a trout pole as the power comes on and the bucket scoops into the earth. Cables taut, it begins to move again as the cab smoothly turns on its seventy-six conical roller bear- ings, as big as dinner plates in diameter. As it nears the end of its arc the bucket begins to descend, while huge asbestos-block brakes check the cab’s pivot. With the precision of a well-oiled clock, the bucket halts directly above the waiting truck and tilts. A single bite fills the big truck to overflowing and off it starts, while the operator gently flicks his levers and starts the great dinosaur moving again—all within a few minutes time. This big machine can pick up a load of dirt, pivot 180 degrees, and set it down nearly a block away. It can reach down 104 feet into an excavation, bring its bite of dirt to its own level or higher, or deposit it fifty-nine feet above where it stands. Or, it can “step” forward or back and add another seventy feet to its reach. Engineers on the Florida Ship Canal faced the problem of moving huge quantities of dirt over a distance too far for one ma- chine, yet too short for trucks to haul it efficiently. They de- signed a machine that looks like a gigantic bird with outstretched wings. It is a huge walking drag- line with a 175-foot arm extend- ing from each side. Along each [Continued on page 120] 55

Page 56

Авг LEGS SPROUT FOLIAGE! -SPROUTS WIM LEAVES THREE INCHES LONG BURST FROMTAI RNE TABLE WAS PURCHASED NON THE ARE | TO BRING FORTH MORE FOLIAGE, d "UN A.L.MARAN, ELIZABETH, Ned. Hes [zm DOWN, INCOME UPI-THE | GRAF ZEPPELIN HAS MADE MORE MONEY SINCE. IT HAS BEENDE- COMMISSIONED THAN IT DID WHEN IT WAS IN SERVICE. THOUSANDS OF PERSONS АВЕ GOING ABOARD TO IN- SPECT THE CRAFT AT THE RATE OF TWENTY-THREE CENTS EACH DOROTHY THOMSON AEON Mee e em oes DIRTIES CLOTHES! Srove GIVES MUSIC!-ANELECTRIC RANGE LOCATED NEAR ABROADCASTING STATION SUDDENLY EMITTED STRAINS OF SCHUBERT'S RIA"-RADIO PROGRAMS ALSO HAVE | FTS CONNECTED 77 "^ WITH ELECTRIC FURNACES:- GA. Dusan, Sbeculiton AM | BECOMES MORE DIRTY AND f 2 Loe Penat |, Five dollars will be paid for the oddity used by Nic Sprank as his leading illustration. One dollar will be paid fon all others used on this page. Send your oddity to Nic Sprank, Modern Mechanix Publishing Company, 1501 Broadway, New York, N. Y. Source or proof of each oddity must be given. Send all oddities separately, not with other manuscripts or letters. | AY m | JENNINGS BERG, MINNEAPOLIS MINM 56 Modern Mechanix

Page 57

Plumbing Fittings Make Novel Football Display NOVEL display conceived by an employe of a leading plumbing fixtures manufacturer features a football team of robot- like figures made from such equipment as elbows, nipples, tees, couplings, etc. Placed in a tradi- tional gridiron setting, the display attracted much attention in the cities where it was exhibited. Erected by two former football players, every figure in the dis- play assumes a technically perfect position. 'To distinguish the two teams, one set of players was finished with white paint, while the other appears untouched. Depicting a technically perfect gridiron scene, the novel dis- play shown in top photo features robot-like "players" made from plumbing fittings. Lower—Parts used to make figures. Nurse Corps Uses Airplanes REPARED to take off at a moment’s no- tice in case of disaster, a corps of aerial nurses organized in Los Angeles, Calif, is fullp equipped to handle emergency cases anywhere in the U. S. The organization, known as the Aerial Nurses Corps of America, is equipped with the latest medical equip- ment and two monoplane "ambulances." Under construction at Chester, Pa., this oil tanker will be » the world's largest welded vessel when completed. Speeding & at 13 knots, the ship will carry 156,000 barrels of oil. HE world's largest welded ship, an 18,500- ton tanker, is being constructed for an oil firm at Chester, Pa. shipyards. The new vessel will be 521 feet long and will have a cargo capacity of 156,000 barrels. Turbo- electric engines developing 5,000 horsepower will give the tanker a speed of over 13 knots, enabling it to make trips between Texas gulf ports and Philadelphia in six days. Members of the Aerial Nurses Corps of America demonstrate how a patient is transferred from an auto to aerial ambulance. December, 1937 57

Page 58

RIDGE HE WILL BE “FORCED TOLAND PANORAMIC VIEW OF TYPICAL SO; EASIEST METHOD OF ACCOMPLISHING LONG SMOOTH FLOW OF AIR DEFLECTED STEADILY EDDIES - "TURBULENCE UPWARDS > аас SOARI RIDGE ee мек ES ASIEST WAY. TO REMAIN А ^ INDICATION « OF RISING AIR | - CURRENTS THROUGH UPHEAVALS Е WHICH ALTITUDE IS RING LIEZ GAINED ON CLOUDLESS, M ss. . DRY DAYS —————— ES = / CL TEES £3 X vd d rr GUY CUN E ufi ЫҸ A ONDENSING AIR FORMS = THERMAL SOARING SAIL PLANE HEADING FOR LARGE CUMULUS CLOUD * CERTAIN SIGN TO PILOT OF RISING AIR CURRENTS. SEE EXPLANATION AT LEFT NS 58 2x cuoc S AN'S nearest ap- proach to true bird- like flight lies in the operation of soaring glid- ers or "sailplanes." Light in weight, with airfoils designed to provide maxi- mum lift with the least forward motion, the sail- plane, with a skillful pilot at the controls, takes ad- vantage of rising thermal (hot air) currents or air deflected from ridges of hills below. Artist's sketch Shows various methods by which famous soaring pilots have made flights of 300 miles and attained altitudes of 10,000 feet. а CUMULUS. 1 7*7 cloups m MANEUVER REPEATED AS „АЗ SUPPLY OF CLOUDS PER D-HOPPING >> UTILIZING CLOUDS FOR DISTANT FLI Ё Modern Mechanix

Page 59

December, 1937 Few thrills can compare with that of riding the wind in a sail- plane. In Germany, where soaring has developed its greatest following, over 12,000 sailplanes are flown by the nation's 50,000 glider pilots. Top—A sailplane sets out for a flight over a valley. Above—Carrying sailplanes to the top of a hill for some ridge soaring. Left— Studying a map to determine most likely soaring terrain. Upper left—Time out for re- freshments while waiting for better air currents to develop. 59

Page 60

Are HOME— Flying a home-built plane (right) is a privi- lege enjoyed by resi- dents of only a few states. Right lower— An “Air Camper’’, built from MM Flying Manual (1932) plans. Circle—Many men now prominent in the aviation industry can be thankful that more liberal air laws were in force during their early days, enabling them to secure low-cost aviation knowledge through construction of their own planes. Above—Many an amateur built his plane in his back yard. 60 Letters from readers indicate a rebirth of interest in amateur avia- tion field. AN the amateur airplane builder success- fully construct a light airplane which he can depend on to perform reliably in the air? Having constructed it, can he use the knowl- edge thus acquired as a stepping stone to a worthwhile job in aviation? The answer is, “YES—if it weren’t for government restric- tions that keep the amateur plane builder grounded except in a few liberal-minded states that encourage amateurs.” Home-built aircraft, if constructed to re- liable plans, can be as safe as any aircraft of equal size and power that carry an NC license. The experience of Oregon, and several other states that permit home-built aircraft to be flown, bears out this statement. Modern Mechanix

Page 61

Built Planes Safe? Above—Amateurs CAN build aircraft that rival commercially- built planes in craftsmanship, design, and beauty of finish, and—they are safe, too, as records prove. Below—An amateur's partially constructed plane. Note excellent work. From 1929 to 1933, inspired by the belief that thousands of young men throughout the country were intensely eager to own and fly their own airplanes, Моревм MrcHanrx pub- lished annual Flying Manuals containing re- liable plans from which amateurs could, and did, construct dependable light airplanes at a moderate cost. The sales figures of the manuals proved that our belief was correct, and MopzRN МЕСНАМІХ only stopped publish- ing an annual Flying Manual (although back issues of the 1931-32-33 editions are available at 50 cents: each) when federal restric- tions on the flying of home-built planes were adopted by a majority of the 48 states. Recently, we received quite a few letters from readers interested in building airplanes —letters asking us to provide the latest in- formation regarding government laws on the subject; asking us to campaign for more liberal laws relating to the building and flying of home-built planes; and letters urging us to propose some plan that would help the light plane enthusiasts and still be approved December, 1937 The welded tubing motor mount of the home-built plane in the upper photo can be favorably compared with any found on commercially built "flivverplanes". Lower photo—A home- built airplane powered with a converted Ford auto engine. by the government aviation authorities. The re-birth of interest in home-built air- planes, as indicated by the number of letters received, caused MopERN МЕСНАМІХ to inves- tigate the possibility of changes in the laws now in force. Sad to relate, there seems very little chance of any changes occurring in the near future, if ever. A bulletin issued by the Bureau of Air Commerce states that its engineers feel that the requirements for light airplanes can be [Continued on page 141]: 61

Page 62

Fleet Of 398 Planes Tests London's Air Defenses These Avro Anson bombing planes were part of a fleet of 398 aircraft that participated in a mock attack to test London's air defenses. Tests indicated bombers "destroyed" the city. Beading "Dresses Up" Auto OTORISTS are able to accentuate the graceful lines of their autos through use of a combination of molding and beading developed by a St. Louis, Mo., firm. Use of the combination material is said to make the body appear longer and low-swung without obscuring the make of the auto. The combination consists of a streamlined radiator grille and a series of raised molding strips which are carried back along the panels of the doors and sides of the auto, ending in a narrow, graceful sweep at the rear. Strips are obtainable in colors. А combination of a streamlined radiator grille and a series of raised molded strips carried back along doors and sides give this cat a smart appearance. Strips have colored finish. 62 ONTRIVED to test the air defenses of London, a monster sham battle involving the flying of 398 airplanes of various types was staged recently by the Royal Air Force. A force of 176 bombing planes tested the anti- aircraft defenses of the city, while 222 fighting planes went up to "shoot" them down. The air exercises also afforded an oppor- tunity to test the Civilian Observer Corps, whose members served to spot the attacking bombers before they reached London, com- municating their positions to the defense flying squadrons. Searchlight crews also participated in the sham battle. The results of the mock air attack indicated that the city had been “destroyed.” Clock Indicates World Time Designed primarily for short-wave enthusiasts and airport use, this universal electric clock simultaneously indicates the correct time at 16 large cities scattered over the globe. NEW electric clock invented by F. O. Kaeppler, of Los Angeles, Calif., simul- taneously indicates the time at sixteen or more cities scattered over the globe. A hair- line crossing a series of scales enables the user to read the time at any location shown. Although the device is designed primarily for short-wave radio enthusiasts, it is ex- pected to prove useful at airports, railway stations, and brokerage offices. Modern Mechanix

Page 63

Surgeon Devises Special Forceps To Treat RACTICALLY all foreign bodies lodged in the stomachs of dogs can be removed quickly, painlessly and safely in from three to five minutes through use of an instrument developed by Dr. Ray- mond J. Garbutt, chief surgeon of the American Society for Preven- tion of Cruelty to Animals in New York. Spark plugs, iron washers, . ball bearings, lead sinkers and stones are some of the unusual objects removed from the ailing canines' stomachs. To remove the foreign bodies, Dr. Garbutt uses a special forceps which, after sterilizing, is gently passed down the animal's oesoph- agus. A fluoroscope is then used to de- termine the exact position of the foreign body in relation to the forceps, after which the jaws of the latter are closed firmly over the objects and gently withdrawn. A gen- eral anaesthetic is administered to the dog patient during the “operation.” Electric Blanket Perfected LTHOUGH it weighs no more than an average blanket, a newly perfected elec- tric comforter features two thicknesses of light-weight material between which many feet of specially insulated and water-proof flexible wire have been sewn. The wires are connected to a current control box which can be placed at the head of a bed and operated by the sleeper or, in the case of an ill patient, an attending nurse. This nurse is adjusting the compact thermostat and trans- former device that safely regulates the amount of current supplied to the wiring of a newly perfected electric blanket. December, 1937 Dogs Top—Dr. Raymond J. Garbutt examines the special forceps he P aeveloped for removing foreign objects from dogs’ stomachs. Lower photo shows how forceps are used to pain- lessly remove unusual objects that canines sometimes swallow. “Indestructible” Plane Built EATURING construction that makes it practically indestructible by machine gun fire from other aircraft, a “convoy fighter” airplane has been developed by the Seversky Aircraft Corp., of Farmingdale, L. I. The all- metal construction is such that the stresses of flight are spread over the entire wing and no single beam carries a critical load. The wings can be literally riddled with bullets and the plane can still maintain flight. The new plane is powered by an 1100- horsepower, twin-row radial engine and is said to be capable of traveling 300 m.p.h. Armament consists of five machine guns and wing racks for carrying 300 pounds of demo- lition bombs. The plane is believed to be the most versa- tile ever constructed for military use. It can be used as a light bomber, an observation plane, a pursuit plane, an attack plane, or as an advanced trainer. 63

Page 64

Above—Scraping loose soil from dried adobe slabs. Rig ht——Heavy timber poles are used to make the door frames. ANTASTIC as the statement may seem at first glance, it is quite possible for any- one without previous experience in building to construct a modern, durable and artistic dwelling out of mud, or—to use the old Spanish-Californian name—adobe. This has been proved by a number of residents of the San Ramon Valley in central California. 64 Rows of adobe bricks drying in the sun. The main requirements are a supply of ordinary dirt that does not contain tog high a percentage of sand, enough water to thoroughly dampen the adobe mixture, and plenty of sunlight. Add to these a truly Spanish disregard of time, infinite patience and a strong pair of legs, and you are as well equipped as others who have successfully built their own houses out of native soil. It is well known to students of California history that most of the missions built by the Spanish padres who first explored that state were made of adobe. The prime reason for this was the scarcity of timber in some sections. Yet, after more than a century of Modern Mechanix

Page 65

The roof rafters, of native timber, are supported at the ridge by a log extending through each gable end wall, as shown in above photo. Right—Setting in the window frames. Below —When completed, the outside of the novel house is whitewashed to create a teal Spanish appearance. use, many of the old Cali- fornia missions are still standing and habitable. In Mexico and other longer settled countries, adobe buildings over two hundred years old are still occupied. During the past few years a revival of interest in adobe construction has taken place in California. Although he does not claim the distinction, Harry H. Hindman, a resident of San Ramon Valley, is credited by December, 1937 Modern adobe dwellings are easy to build. his neighbors with being the “pioneer” of this renaissance of an ancient craft. Hind- man’s adobe house has served as a model for a number of others in that part of California. Departing radically from the classic Spanish design which consisted of a square, box-like structure surrounding a court or patio, Hindman and his neighbors have built [Continued on page 148] 65

Page 66

This automobile wheel, invented by Chris Sauer, of Chico, Calif., is said to eliminate blowout accidents by locking deflated tire to it, making the two one unit. Although torn to shreds, test tire remained locked to wheel at 65 m.p.h. Auto Gun Holder Invented DAPTED for use with any revolver from .22 to .45 caliber, a newly invented holster compartment is easily and quickly attached to the bottom of an automobile in- strument panel, The compartment features a special door fitted with a lock that not only protects the gun from theft, but which automatically thrusts the gun into the user’s hand when the lock is tripped. The holster is constructed of heavy gauge iron. Located conveniently at the base of an automobile instrument panel, a new revolver holster compartment flips open and thrusts gun in user’s hand when a special lock is tripped. 66 Flanges On Wheel Prevent Tire Blowout Accidents N AUTOMOBILE wheel designed to pre- vent accidents that result from tire blowouts has been invented by a Chico, Calif., tire dealer. Tests in which a tire was blasted by a shotgun while the car was speed- ing at 65 m.p.h. are said to have proved the merit of the invention. The wheel features two metal flanges which serve as a tire bead lock when the tire is inflated. The flanges are one-quarter inch in height and extend for approximately the entire circumference of the wheel. In event of a blowout, the flanges serve to keep the tire locked to the wheel, eliminating the vi- bration that normally occurs when a blown. tire becomes disengaged from a wheel. Public Teletypes In Service Featuring dials similar to those used on telephones, tele- type machines have been placed in operation for public use in Germany, Wooden cabinets can be locked when desired. ELETYPE apparatus for public use is the latest means of communication .in Germany. Dial devices, like those used on telephones, enable individuals to establish their own connections through eleven central offices now in operation throughout the country. The teletype machines are housed in compact lockable cabinets of sturdy wooden construction. Modern Mechanix

Page 67

GIANT FLYING BOATS NEAR COMPLETION NCIB'SBI А fleet of six giant flying boats like the one sketched here is being built for Pan American Airways by the Boeing Aircraft Company. With a wingspan of 152 feet and an overall length of 109 feet, the four-engined planes will each carry 50 passengers. ESIGNED to earry 50 passengers on 24- hour schedules between America and Europe, a fleet of six giant flying boats has been under construction at the Boeing Air- craft Company plant in Seattle, Wash., for more than a year. Huge three-deck liners, the planes will each be powered by four 1,500-horsepower Wright Cyclone engines. Despite their weight of 4215 tons when fully loaded, the giant flying boats will fea- ture a top speed of about 200 m.p.h. Cruising range, with 50 passengers, will be 3,200 miles. The hull length of the new planes is 109 feet, while the wingspan is 152 feet, making the new craft about twice the size of the Sikorsky Clipper planes that recently made survey flights across the Atlantic for Pan American Airways, the air line for which the Boeing flying boats are being built. The cut-away drawing identifications are: (1) anchor hatch, (2) seamens’ compart- ment, (3) the bridge, where flying controls are located, (4) First Pilot, (5) Second Pilot, '(6) radio direction finder loop, (7) naviga- tion room, (8) radio officer's post, (9) chart room-navigator's post, (10) map case, ma- rine library, flares, ete, (11) engineering officer and engine controls, (12) Captain's office, (13) engines, 1,500 horsepower each, (14) mechanics’ wing section, (15) landing lights, (16) wing, 152 feet, (17) navigation lights, (18) main cargo hold, (19) crew’s sleeping quarters, (20) luggage holds, (21) radio antenna, (22) passenger compartment, (23) spiral stairway to bridge, (24) men's retiring room, (25) galley, (26, 27, 28) December, 1937 lounges, (29, 30) passenger compartments, (31) women's dressing room, (32, 33) pas- senger compartments, (34) pumps for trans- ferring fuel from wings, (35) auxiliary hold. Sprayer Travels Over Lawn LOCOMOTIVE lawn sprayer invented by William Н. Soper, of Denver, Colo., pulls itself along by winding in a light wire cable which may be staked out for one hun- dred feet from the machine. While slowly traveling, the machine throws any type of spray through an arc of 180 degrees. The lawn sprinkler travels over grass or along a sidewalk and, once set, requires no attention until the entire cable is wound in, upon which it automatically shuts itself off, thus preventing waste of water. The machine is driven by the water pressure in its hose, cylinder and valves. Driven by the water pressure within its valves and tubing, - this lawn sprayer pulls itself along by winding in a light wire cable which is attached to a stake placed 100 feet away. 67

Page 68

Winners in"Midget Mike" Model атар Contest Pictured above is James W. Kendrick of Battston Spa, New | York, first prize winner | in the “Midget Mike” locomotive contest. His prize model, No. 4517 of the "Little River R. R."is shown at | right. Mr. Kendrick’s craftsmanship won for him a complete kit for building an 00 gauge, Hudson type, N. Central locomotive. Dr. Charles A. Layton. Detroit, Mich., was re- cipient of the second prize award for his "Michigan Central"-— "Midget Mike" model. NCE more the accuracy of Modern Mechanix con- Struction plans has been at- tested by readers who entered the recent "Midget Mike" model locomotive contest. At is conclusion of the three-installment article describing the building of the authentic lilliputian locomotive, the editors announced a group of valuable prizes to be awarded for the best models submitted by readers. The winning models appear on this page. First prize was given to James W. Kendrick, of Battston Spa, N. Y. His. reward was a complete kit of machined parts for building an authentic Hudson Third and fourth prize models, pictured above, built by B. d W. : Gruger of Schenectady, М. Yo aud Wilham G беге ші Brooke N.Y, type, New York Central locomotive. Dr. Charles A. Layton, Detroit, Mich., received a complete kit of parts for building an air conditioned Pullman coach, as second prize winner. Third prize, a complete kit for build- ing any one of 17 different types of freight cars, was awarded to Bernard [Continued on page 136] Irvin W. Streng, a Chicago, Illinois, model locomotive enthusiast, received Modern Mechanix’ fifth prize for this "Illinois Southern” version. 68 Modern Mechanix

Page 69

Headline Hunter Preserves Old Newspaper Copies OLLECTING newspaper headlines of im- portant events is the hobby of Mont- gomery Mulford of Buffalo N. Y. Each headline selected is photographed and placed in an album for safekeeping. The upper pho- tograph shows a copy of the Buffalo Express telling of the sinking of the Lusitania. Below is a photograph of the issue explaining the false armistice of November 8, 1918. Al- though keen disappointment was felt when the armistice report was found to be false, the nation had but a few days to wait before the actual armistice was signed. Like postage stamps, old copies of news- papers many times become rare and achieve considerable value. Some copies of news- papers telling of world events are worth a fortune. — Special Engine Powers Radio The trans-Atlantic plane "Caledonia" during an overhaul pre- · paratory to one of its trips. The smoke is from a gasoline engine used to supply power to the special radio transmitter. HE Imperial Airways liner “Caledonia” of trans-Atlantic fame carries a special gasoline-driven generator for supplying power to its powerful transmitting equip- ment. Two-way radio aboard planes has done much to eliminate danger to the crew and passengers as well as the plane. In trans- ocean crossings, communication with both sides gives the pilot complete knowledge of weather conditions along his route. After air travel across the Atlantic be- comes established, passengers probably will be able to converse with friends on shore, as steamer. passengers do at present. December, 1937 When the Lusitania sank newspapers carried screaming head- lines. One of these, as well as one explaining the false armistice, is in the collection owned by Montgomery Mulford. Car Serves Home, Business COMBINATION truck and passenger car gives two-car use with one-car pur- ` chase. During the week the car can be used asa truck. For week-end use by the family, the two rear seats are replaced and the truck has been turned into a passenger car. By removing two seats, ample space is obtained for carrying merchandise, equipment or tools. With seats replaced, the car is suitable for taking the family for a week end or short trip. 69

Page 70

NEW STAMPS FRO WAR.TORN SPAIN By Montgomery Mulford HE postage stamps which have come from Spain during the first years of its civil war have been mainly those issued in the territories conquered and controlled by General Franco. If Franco’s cause does not finally triumph, philatelists the world over are going to find that these stamps will be- come a mighty fine investment. If Franco wins, the issues will be known as provisionals and first issues; but those used on covers— postally cancelled envelopes—will be avidly sought after because they will be com- paratively elusive. | Franco started out with stamps for each province. Most of the stamps were overprinted issues, inscribed for use in definite localities. Thus "Sevilla" or Mallorea (Majorca) would have postage stamps which could be used only within their areas. "These In- surgent issues appeared in In addition to the provin- cial stamps issued by the Spanish Insurgent gov- ernment there are also the charity issues. These stamps, like the one pictured at upper right, must be af- fixed to all mail, in addition to usual post- age. such localities as Babajoz. Cadiz, Cordova, Granada, Huelva, Leon, Seville, Orense, San Sebastian, Palencia, Majorea, and Zaragosa. Only by the early part of 1937 did the Franco, or In- surgent government, first issue a regular series to cover all the territories under rebel control. These were inscribed "Espana" and may be at once distinguished from Loyalist (Madrid) republican issues be- cause the latter are inscribed “Espanola.” Besides the provincial postage stamps of Franco’s Spain, there were, in each province. also charity tax stamps which were compulsory on mail-matter. adhesive, it was not forwarded; it was also essential to have the charity or semi-postal stamp affixed. Seville, Cadiz, Orense and Majorca in the Balearic Isles If a letter bore merely the postage were the first to have insurgent postage, which appeared in August, 1936. These stamps were Spanish republican issues overprinted “Viva Espana.” Early in 1937 however, the first regular postage issue for the Franco forces appeared. There were eleven values in the series, lithographed at Zaragosa.. The one center was imperforate, but the rest of the stamps were perforated 11%. Each of the stamps of this issue pictures a famous building in a city under Insurgent control, and has the inscription, “Junta de Defensa National"—national defense junta, or com- mittee. This issue became exhausted by the end of April, and a second regular Insurgent series was brought out. But these [Continued on page 126] These stamps are but a few of the many issued for each province now controlled by the Spanish Insurgent gov- ernment. They may be identified by the word, “Espana” surprinted on them. 70

Page 71

WOODEN MOULD X Н HAMMER AND HANDLE . A CAST METAL. LATHE | тини DINNER GONG HIS dinner gong can be made in the shop, including the casting of the bell if you have a small blast furnace. Its metal is aluminum bronze which has a tone quite struction of the comparable to the musical tones of the famous gong.. The bel Swiss bells. And because aluminum bronze self, is cast ош z ] aluminum-cop p is merely alloy of copper and aluminum, an alloy and furii old~skillet and scrap copper wire can be melted down to provide the metal. Turn first, a pattern of wood to the same shape and very little oversize of the finished bell. Its maximum diameter should be 544 inches, its depth, 1% inches and the walls about -inch average. This increases some- what at the very rim. Bore a 12-inch hole squarely through the center. This pattern, when a 14-inch iron rod is inserted in the hole, becomes the counterpart of the bell and is placed in the flasks and the moulding sand packed in the usual way about it. Before separating the flasks the rod is removed carefully and this becomes the well for the metal. [Continued on page 136] po The above pictures WOODWORKING . RADIO . METALCRAFT . AUTOMOBILES . CHEMISTRY _ BIOLOGY . MODEL BUILDING - ELECTRICITY . HOME AND SHOP KINKS _,

Page 72

by J. Julius Fanta F YOU'RE looking for a new iceboat design, you'll like Polaris, the latest creation of the Hudson River type and a fast, trim racer with a moderate rig. This craft is a departure from the usual "banjo" cockpit model in that the crew sits upright and steers like a car. A comfortable boat in heavy winds, \ \ Polaris is 20 feet long and carries 90 \ square feet of sail. No jib is neces- \ sary, as this sail has proved useless on iceboats. There are two cockpits, one located in front of the other. The Tangle iron runner blades prescribed are designed for sail- ing in snow as well as on clear ice. The laminated backbone con- struction, which is relatively simple, makes the hull ex- tremely staunch and check- proof. Polaris is steered by remote control, with the steering quadrant coming back into the fore cockpit. Specifications given here provide not only for a weatherable craft but an attractive one. At the outset, get а good conception of the 72 Modern Mechanix

Page 73

construction by studying accompanying plans. Note that Polaris calls for improved methods of building; so keep in step with modern ice- boating by adhering to details. Clear, straight-grained Sitka spruce should be used for the side walls of the backbone or center body. Saw the 34-inch stock of 20- foot lengths into 2-inch strips for the lami- nating work. Reverse alternate ends of the strips so that the wood, when glued up, will bear greater strength. . For appearance's sake, alternate strips of mahogany or walnut may be placed between spruce. But it would be vain to glue the strips without reversing the grain, as no benefit will result. Casein glue is essential because it is stronger than the wood. Mix the powder- form glue with cold water and beat until it becomes a thin batter. ' To laminate, glue the strips as aforemen- December, 1937 The bottom of the backbone is shown in the photograph above. Note how the crossed steering cable is drawn taut around the 8-inch grooved wheels with a turn-buckle. Left—The laminated deck with tiller and sheet traveler ` just ahead of the fore cockpit. Drawings should be followed so as to obtain correct hull shape and the proper spacing for the bulkheads. tioned to build 12-inch wide side walls. Clamp the job and allow the glue to dry 24 hours before removing the clamps. Chisel away the glue which has oozed from the seams. Now taper the sides to the dimensions given in drawing. The bottom of the sides bear a 2-inch arch. The bow, or head piece of solid 4 by 6 by 615-inch oak, is glued between the fore ends of the sides and screwed with 2-inch F. H. brass screws. Work back from the bow in placing the bulkheads at the required distances. Use 3g-inch plywood for bulkheads, bordered with cheek pieces of 34 by 14-inch pine. Fasten the plywood to the frames flush. Spread the side walls until the proper width is obtained; then fit in the bulkheads by beveling as necessary. All bulkheads forward of the cockpit PE fo

Page 74

NG BRASS СНАРІ PLATE EA- SIDE gu jen. E 222 SND OF Е aS 2 PLAN : BEERS SECTION THRU CHOCK RUNNER PESE 74 3 REAR (RUDDE 1/2" HOLE INATIONS Т LM 1-5/8" OAK )yCHOCK м2 INS REVERSED should have 2-inch air holes to ventilate the hull. To bring the back ends of the sides together, for the stern-piece, use a light rope sling twisted уһ а club. The stern piece, of 4 by 10 by 10%4-inch oak, is beveled to fit the taper of the sides, between which it is glued and screwed. А special bulkhead must be constructed for the rudderpost. This is described in an ac- companying sketch. Between the third and fourth bulkhead, at the bow, a fore and aft wooden plate is fitted to support the mast step. All bulkheads, the mast plate, bow and stern pieces and the rudder post block are flush with bottom and top of side walls, at their respective stations. Next cover the bottom with % by 2-inch pine planking, fastening it to the bulkheads and sides with 1!4-inch brass screws. Round the corners of the bottom slightly with a plane. The deck, of % by 2-inch spruce or Angle iron hobblers are welded to %-inch iron plates and the entire unit bolted to runner plank. Modern Mechanix

Page 75

7 ЖА BEND OUT js LENGTH И 25 /[/] REQUIRED 1" SQUARE ; j | 8" GROOVED QUADRANT WHEEL PINS; T Sy шгар: TO PIPE l8xl'DEEP gu HERE 4 x |I" PIPE d RUDDER POST CHANNEL- WELD TO PIPE FLANGE SLIDING FIT FLANGE SCREW , OR BOLT TO DECK 4 Х15" PIPE T TILLERPOST 2 HOLE / A C— 8" DIAM. GROOVED WHEEL-PIN TO PIPE BOTTOM VIEW 2" X 12" SOLID OF MAST EYEBOLT SPRUCE RUNNER ce TE PLANK 13' O" LONG pine, is glued to the side walls and bulk- heads and fastened with screws. All screw Wes RON heads, wherever used on Polaris, should be PLATE | 12" countersunk and covered with plastic wood. Before gluing the gunwhales around the cockpits, glue 1 by 1Y2-inch oak ribs across the bottom and inner sides of the cockpits. Cut rib tops flush with top of side walls and cover gunwhales 1% inches wide. The hole for the tiller post is 34-inch diameter drilled 3% inches from the fore f S of WELD end of the forward cockpit. The %4-inch 3" X 3" Foe diameter rudder post is 7 inches from the IRONS HOBBLER DETAIL stern. DRILL FOR v2" -A MACHINE BOLTS DRILL 1/2" FOR KING BOLT [Continued on page 124] December, 1937 75

Page 76

WINTER SPORTS PROJECTS An AirLine Skating Glide W sl SAN e | NN | Y N HIS air-line glide provides thrills in taking off and coasting on ice skates. Install the rig between trees on the banks of a stream, the rope trolley being from 50 to 60 feet long, with the ends tied to the branches about 10 feet above the ice. The trolley car consists of two 1-by-4-inch boards, 2 feet long, with 2-by~4-inch blocks nailed between them at top and bottom as shown. A broom-stick or willow pole serves for the handle bar. s» | ice Tub Whirligig Provid WASH TUB ГА DD exciting fun to your next skating party by taking along this whirligig tub, and giving everyone in the crowd a trial spin in it. Find an old metal wash tub, too old for further service, and equip it with three sliding pegs. These consist of wood blocks 6 inches in diameter, with holes bored at the center of each, and a length of broom-stick glued and nailed in place. Fasten the blocks to the bottom of the tub with nails or screws, set equidistant apart. Use a 30-foot heavy trot line or rope, attached to one of the handles. The three sliding pegs should be rounded smoothly, and the tub used only on smooth ice. Short pegs make it almost impossible to upset the tub. Multiple Sleds Form Snake Coaster TW HIS inexpensive coaster will take a twisting coasting trail easily, twisting and turning, with the springy strap-iron runners adding more thrill. Saw up a 1-by-12-inch pine board into: 3-foot lengths for the “cars,” with the leading bob having a reach board 4 feet long. The front sled has a steering device, consisting of a 1-by-3-inch bar, 2 feet long, bolted at the middle. Runners are of 1 by 9 and 1 by 14-inch strap-iron. STRAPIRON ; 9 т а е) Mono-Runner Sled Is Easily Built REACH BOARD 1/2" XIX 4-10" TRAP-IRON 34-inch wide forms the main runner of this fast sled, and the two short steering bobs as shown in the drawing. Use a strong board 14-inch thick, | 1l inches wide and 4 feet, 10 inches long for the reach board, rounding the corners at the front. The front bob stick is hardwood, 2 feet, 4 inches long, with the ends whittled into handles. Bend the strap-iron mono- runner into shape and drill and fasten it to the bottom of the reach board with stove bolts. SCREWS

Page 77

- Simplified Toboggans Provide Winter Thrills The toboggan pic- tured at left can be assembled in less than one hour. It is constructed of scrap wood with only two tools—a hammer and saw. The bottom sur- face is wax finished. HESE easy-to-build toboggans are not only efficient, but can be built at prac- tically no cost. The simpler design can be assembled from scrap pieces of wood, while the plywood model should not involve a ma- terial expense of more than $1. The “Hammer and Saw” toboggan consists of a 12 by 40-inch runner board and 12 by 14-inch nose attached to the main member with a 2 by 6-inch cleat as shown in the details. Plywood is used to form the nose and runner of the “Built-Up” model. The ve- neering is screwed to a 34-inch pine board, 48 inches long and 12 inches wide. The nose is then clamped to the side brackets to com- plete construction. The bottoms of both ` models are sanded smooth and waxed. = SIDE VIEW = while bottom is sand- Hi Sibley Somewhat more elabo- rate, this snow craft is also easy to build. Its cost should not exceed $1. The runner is formed of plywood, re- - inforced with pine. Top of toboggan is varnished papered and waxed. NOSE CLEAT —»! Я SIDE. BRACKET Ew J—BUILT UP TOBOGGAN — `

Page 78

METHOD OF LAYING OUT A 5-РОІМТ STAR by Ray J. Marran F YOU desire to make something unusual and out of the ordinary to brighten the home at Christmas festivities, something that will add cheer and decorative novelty to the Christmas dinner table, try your hand and power tools in producing a few of the novelty candle holders illustrated on these pages. All of these holders were specially designed for the Christmas candle. They are easily and quickly constructed by cutting the parts on a small jig saw and a lathe. When carefully painted with several coats of quick drying enamel in the regulation Christmas colors of red, green, white and silver, these candle holders make exceptionally attractive and appropriate center-piece decorative units for the Christmas table, or for the mantel shelf. Cut the parts from white pine and three-ply paneling, following a design unit similar to those in the illustrations. To lay out a perfect 5-pointed star, scribe a circle The jolly Santa Claus charac- *A" the desired size. Divide ters shown below are cut the diameter into l4—points from thin plywood and at 3 tached to а 24-inch pine base. F, B, C, L and I. Scribe the These Old English Carolers are cut from thin plywood, laid out to the l5-inch pattern shown. 78 Modern Mechanix

Page 79

circle “B”. Divide the line “С” to “B” into 1/3—points B, E, D and C.. The line from “Т” to "D" will be exactly 1/5 the circum- ference of the circle *A"; this measurement is used to mark the points J, K, G, H and I. Straight lines drawn to these points form the outline of a perfect 5-pointed star as shown. The stars required for the decorative unit are then cut on a jig saw. Stars cut from 3- ply paneling may be cut four to six at one Left—Before cutting candle holder to shape, drill a hole in the center of the plywood block large enough to accommodate the 77 tall white or red Yuletide taper. The Santa Claus candle holders pictured on the opposite page are made from either this pat- tern or the one illustrated below. Before mounting, paint figures. time by bradding the stock together as shown. Note that a 34-inch center hole for the candle butt is bored in the plywood before the design is cut. Star candle holders may be used as a single unit; or they may be mounted on a circular disk cut from %4-inch stock and painted aluminum or bright red. А combination of stars, mounted on a base- board, or elevated slightly with round up- rights, makes attractive decorative units for three or more Christmas candles. The base is enameled glossy red, the stars glossy white and the trees а combination of bright reds, greens, yellows and silver. [Continued on page 126] the star ! Paid V игъ Ns 1-8 | Bis mn ape- December, 1937 Ји | | eee TT EPA HAE e 5275 The craftsman can vary the antics of the Santa Claus characters by making several different kinds. patterns, laid out on tissue paper or sketched directly on the wood. The characters are then cut to shape, sanded, painted and attached to the base. м > Е ЯН In each instance they are made to 14-inch squared 79

Page 80

OMBINING the beauty of natural walnut with shining brass fittings, this useful and attractive nut bowl and mallet allows the craftsman to display his skill twofold. While both a wood and a metal turning lathe were used in making the original set, the potential constructor will not be handi- capped if he does not possess the latter piece of shop equipment. Lacking a metal lathe, the mallet rings can be cut to the required l5-inch height from . brass tubing and shrunk to fit over the ends of the walnut mallet head. Otherwise, the mallet may be turned in its entirety from solid brass. A form of opening flower motif is imparted to the bowl although its size prevents this idea This walnut and brass nut bowl is a distinctive workshop project. from being obvious. However, the lines are distinctive and very appropriate. Turn the bowl from a block 2 inches thick and slightly more than 10 inches in diameter. Before the center spindle is turned down to exact diameter, bore a !5-inch hole, 1-іпеһ deep in its center, make a similar hole in a block of walnut or other appropriate wood with the grain running vertically. Glue the flat and also the dowel joints, bring the tail stock center tight against the piece and let the glue set. Get and smooth a ring of brass about is-inch thick, lo-inch wide and 2 inches in diameter. First turn down the top of the upright so the ring barely starts on. This turning should have a slight taper. Тар it snug, start the lathe and, holding a block of wood against the brass, make it quite hot by rubbing. This expands the brass so that it can be driven tightly against the shoulder before cooling. The whole bowl is then gone over lightly, turned to shape, sanded, rubbed and finished. Lacquer, shellac or var- nish, which is later rubbed with No. 000 steel and finally polished ` with wax, provides a.good finish. The mallet handle is he mallet head is turned. own to a spindle and the ^ by 2-inch brass rings slipped оп and shrunk in lace as pictured above. А Геб Тһе ‘nut bow! near the stage of completion. Polishing is done with the project attached to the “faceplate. Right——After # ‘partially turning the Ё bowl, shape. the anvil stud and shrink a % by 2-inch brass ring over и. | EB pa .80 Modern Mechanix

Page 81

After completing the lathe operation on the ‚ mallet, it is placed in a ff simple Jig and a hole drilled in the center for insertion of the handle. Left—Profile and . cross- section of bowl and mal- let details. Below—Fit- ting the maple handle to the brass trimmed mallet, to shape from a maple dowel. The head is turned down to a spindle and the brass fer- rules of brass to jl-inch in width, diameter and wall thickness shown. In the same manner as was described above, the brass rings are heated and driven to a tight fit. For the walnut, filler should of course be used to fill the grain before applying the finish. The whole unit can be made entirely of walnut, or the bowl can be turned from figured gum or birch, while the mallet and top half of the center spindle, or “anvil,” can be of walnut to provide a pleasing contrast. Completed this bowl will take two pounds of nuts without appearing over full It is an ideal wintertime project and, of course, has commercial angles which the enterpris- ing home shop owner can work out to his advantage. December, 1937 N Q BRASS RING SHRUNK ON W. ALNUT 72" DOWEL LUE JOINT s | =! ANOTHER ANVIL, SUGGESTION If a solid brass mallet head is used, it can be of the same dimensions as the brass trimmed wood head shown. or shanks can be turned between head center and the end faces. Another way to provide а neat brass trim is to dispense with the glued-up center block by soldering a large, flat head wood screw to the under side of a brass disc about Y4-inch thick and turn the screw into a hole drilled in the original center portion. This will make the anvil just 14-inch higher than the bowl rim, but the heavy metal will not blemish with use as much as will the end grained hard- wood block. When this arrangement is used the center hole must be slightly countersunk to accommodate the screwhead so as to per- mit the brass disc to fit tightly against the wood. The protruding edges of the solid brass are then turned down flush with the wood center and finished in the usual way. ру DOIG R. Van [л | 81

Page 82

6 Gauge Óil- OF CARDBOARD HE model locomotive presented here is of all cardboard and wood construction, even down to the trucks, its total cost being in the neighborhood of twenty cents. The materials, with the exception of glue and cardboard, were bought in the five and ten. However, the trucks may be purchased . complete with a motor and the rest of the con- struction built up of cardboard from “O” gauge plans given here. Metal may be used in place of the cardboard and wood. ay t ; : S EO ee aioe а q^" 2"x 43" piece ноор 21" wipe REGULARLY 3. еаџеўтовооғ / ut ч D y 4 2 Ў OIL COOLER SSS ASSEMBLY e BRACKET ' CELOPHANE FRAMING 1 CN GLUE TO BACK ya “ . OF OPENINGS m ы, WINDOW ©) Y PINE OR DETAIL BALSA PRESS DOWN THRU BRACE Я : RING "8" AND GLUE HEADLIGHTS „Ф PIECES TOGETHER (AIR TANKS MADE IN SAME MANNER) V4" DIAM. DOWEL SUPPORT # 18 WIRE BRACKET MUFFLER DETAIL END PLATFORM (GLUE TO FLOOR) f BALSA K X ae 5 C y) SIDE TRIM FLOOR (3//6" PINE) ж WIRE PIPES STEPS SHAPE \ DETAIL OF TO ROOF EXHAUST 15/16"DIA, CONTOUR STACKS yes WIRE- GLUE To i 2 3/4" Е OUTSIDE FRAMES : 224 тга ЕМО [ TRIM PILOT — BALSA ? 3/4" DIAM. К COUPLER — 24 BONE OR D x DETAIL Dr METAL RING OF WHEELS WIRE END-TIE CUT OUT Ров YN A “22 вамвоо · * [7 Soa ШУ THIRD RAIL INNER FRAME TRUCK DETAIL зле" Ths OUTSIDE FRAME PLAN BALSA . INNER FRAME VARIATIONS INDICATED BY BROKEN LINE CONSTRUCTION DETAILS ALL CARDBOARD UNLESS OTHERWISE NOTED 82

Page 83

lectrice L Live Z CONSTRUCTION EaD у= 7 This unique model is an authentic ver- sion of a Union Pa- cific oil-electric loco- motive. It can be built for 20 cents. Ав either a display model or o he 23: | 16 [-J | ==} =. Overall dimensions of the model locomotive are shown above. Construction is shown in petspective form in details on opposite page. This locomotive is a composite of several different types used on the roads. Either the mufflers or exhaust stacks may be left off at will, de- pending upon the builder's creative desires. Begin the model by making the trucks, building them up on a section pue TO ACCOMMODATE с gauge track so as to avoid any chance of mistakes when spacing the TES оа | = wheels. The pattern for both inside and outside frames of the trucks will be found on the accompanying plan. Make the inside first by folding the patterns over into box shape and gluing them securely at the The model can be fitted with s 1 a regular “О” gauge motor by seam. After they have dried, Poe runi e ED add the top and pivot disk. (сы n сша qaty ; in the floor for insertion o [Continued on page 140] the motor, as shown at right. КУС 83 CHANGES NEEDED TO INSTALLMOTOR (CROSS SECTION)

Page 84

Left—A 3⁄4 by 21% by 8 inch block of maple forms a handy scroll saw blade holder. Holes are drilled in the end of the block, a notch provided in the center and the holder attached to the saw arm with a strip of metal. Above—A strip of paper wrapped around taps prevents breakage from undue pressure. Assembled from scrap pieces of pine, the auger bit rack pictured at right makes a useful workshop accessory. The two vertical and two horizontal pieces are nailed together and four spring-type clothes ` pins attached to the cross members with staples. Bits can be in- serted in the rack by pushing the shank against the pin jaws. yt му Sy WN PINS TO RACK WiTH B STAPLES Y h.p. electric motor, fitted with an arbor and cir- cular saw and mounted in a box, as shown at left, permits sawing of lengthy lumber, uniformly straight. A length of stove pipe, a 100-watt bulb and a por- celain socket form this serviceable shop glue pot. Mount the socket on a wooden base, placing the stove pipe and glue con- tainer over it as described in phantom detail below. SACK BRIS" 3 PINE CLAMPS GLUE POT INSERTED INSIDE An old wash wringer, from which the rollers have been removed, will find practical epplication as a saw filing vise. Fit the origi- nal wringer clamps with ?4 by 3 by 15 inch pine boards, cut away roller supports on one side and mount to work bench. 84 Modern Mechanix

Page 85

Kinks Tuar SiMPLirY Home Tasks Wedges Prevent Creeping Of Casters VERY housewife knows how annoying it is to have the casters supporting an electric washing machine < creep so that the washer must be pushed back to its proper USE HALE or SPRING location every few minutes. With the aid of a few spring- CLOTHESPIN PUSM IN BETWEEN clip clothes pins, this nuisance can be permanently elimi- YOKE TO PREVENT MACHINE SLIPPING nated. \ Remove the spring from the wooden jaws and insert the resulting wedge-shaped pieces between the caster wheel and yoke. The wedges will lock the casters so that the machine will remain in a fixed position.—A. H. Waychoff.

Inner Tube Aids Thawing Of Pipes HERE it is necessary to frequently thaw out an ex- posed hydrant riser, the use of an old automobile .inner tube will not only do the job quickly, but at the

HYDRANT---^

same time, end the accumulation of ice that usually forms RISER after the hot water, poured around the pipe, has cooled. Cut the inner tube at the valve stem and seal up one used end with tire patching cement. After the cement has been END OF allowed to set, wrap the tube around the pipe and fill it Hes Дуна : with boiling water. In a few minutes the heat of the water. | ro РРЕ__. òo ^— in the tube will melt the ice in the hydrant, and the water E ,'INNER TUBE will once more flow through it. Spring Opens Clogged Drain Pipes HERE commercial drain cleaners fail to produce mE any noticeable effect on the passage of water through a elogged drain, it is advisable to remove the trap or plug and remove the accumulated sludge by mechanical means. For this operation, nothing serves the purpose better than an old seat spring attached to a length of broom stick with small wire staples. The spring is inserted into the pipe with a twisting motion. When withdrawn, the sediment is ejected without mess or bother. MONKS CLOTHS, BREAD TIN- \ t „277 SEAT SPRING COIL

~= BROOM STICK

A Simple Home Humidifier CCUPANTS of homes heated with hot- air systems may be protected against dryness of the skin and throat by simple humidifiers installed over each hot air regis- ter. The air conditioner, illustrated at right, consists of а tin bread pan mounted over the = register with strap iron brackets. A piece BRACKETS An of monk’s cloth is hung over the pan and SCREWED TO; the latter partially filled with water. The cloth is thus saturated with water so that it is drawn upward by capillary action, causing it to mix with surrounding air.—Hi Sibley.

December, 1937 85

Page 86

Page 87

ee One of the applicator's many uses: an aid in relieving rheumatic and muscular pains. to fit threaded tube; 1 aluminum drink mixer of the type illustrated; 1 10-watt, clear-glass lamp bulb; 6 feet of lamp or asbestos-covered heater cord; 1 separable plug for connecting to lamp socket or wall outlet; 1 wooden handle, which can be a 5-inch length of broom stick. If desired, a spring-type cord protector, like the ones found on electric iron plugs, ean be added, for further protection of the wire. In the bottom of the drink mixer, punch a hole and enlarge it so that it will receive the threaded nipple. Connect one end of the wire to the socket, screw the threaded nipple into the socket, and run the wire and nipple through the hole in the mixer bottom, from the inside. Clamp the socket in posi- tion by screwing the nut over the nipple, centered with respect to the sides of the con- - {аїпег and attach the connection plug to the other end of the wire. It is a good idea to provide some means of preventing the edges тык аш n ge Ке of the threaded nipple watt bulb, shown installed in fore. : the shaker, will provide an Í a [Continued on abundance of heat. Below— А раде 132] Wiring of the socket is done before the applicator is as- sembled. Ап electric iron plug spring, fitted to the end of the aluminum shaker, will eliminate wire breakage.

Page 88

Page 89

ee paina DISTRIBUTOR This photo of a modetn automobile motor shows where to look for trouble in the ignition system. Trouble often occurs in the cables, distributor or generator. Sometime all three may be at fault. Right-—A simple way to charge a weak battery. CAR TO MAINTAIN STRONG CAR BATTERY you can determine this yourself by a sim- ple viscosity test. Place a tablespoonful of oil in a small bottle and allow it to remain outdoors overnight during a cold spell. If the oil, after being exposed to the elements, be- comes too hard to pour, you may be sure that it is not suitable for use in the crank- case. In order that the gasoline is converted into vapor for firing the cylinders, a cer- tain amount of heat is required. Even the best grades of gasoline cannot be expected © to function properly unless the chemical changes they require are given proper consideration. The quickest way to ac- complish vaporization of the fuel is to heat the manifold of the engine externally. This may be done by resting an electric iron against the manifold or playing the flame © of a blow torch on it for a few minutes. With this simple treatment the motor will start almost instantly if the engine is first turned over a few revolutions with the choke momentarily pulled out before the ignition switch is turned on. [Continued on page 142] VAPORIZE FUEL BY PLACING A HOT ELECTRIC IRON AGAINST MANIFOLD REMOVE DISTRIB- UTOR CAP AND . WIPE OFF BOTH- INSIDE AND OUT- SIDE OF CASE — FOLLOW WITH ALCOHOL WIPING WITH CAP OFF, FILE THE ROTARY CONTACTS AND POINTS Many winter starting -annoyances can be remedied if the suggestions outlined in the illustrations at left are carried out. 1—-An electric iron held against the manifold will aid in vaporizing the gasoline. 2—Clean both inside and outside of bakelite distributor with a clean cloth and alcohol, then (3) file rotary points and contacts. 4-—То prevent power leakage, waterproof high- tension cables with ‘several coats of shellac, varnish or clear lacquer. . 89 e

Page 90

AUTO REPAIRING TIME SAVERS Dressing Applied With Fly Sprayer Y APPLYING top dressing to the roof of the car with a common household fly sprayer, a neater job can be accomplished, and in much less time than re- quired when application is made with a brush. Clean out the fly sprayer and fill it with the top dressing com- pound, thinning it with the solvent recommended by the manufacturer. The fine mist ejected by the sprayer will spread evenly and at the same time penetrate the thin cracks and crevices which have formed in the roof covering. Coil Spring Reinforces Radiator Hose — seawc 34" SHORTER (CONSIDERABLE trouble is often experienced with the THAN HOSE ~, radiator hose on heavy trucks and tractors collapsing, resulting in the stoppage of normal water circulation. Since the replacement of the hose in many instances serves only as:a temporary solution to the trouble, a more permanent repair is desired. To permanently end this annoyance, obtain or make a spring with a diameter a fraction larger than the inside diameter of the inside of the hose and % inch shorter than the overall length. Force the spring into the hose and replace between radiator and motor block as before. Elimination of hose соПарѕіоп will result.—A..M. Chester. WIPER WITH SMALL А Glycerine Helps Windshield Wiper : WIPER WITH SMALL RAG aa URING the winter months the windshield wiper of the car requires special attention so that it will be in good working condition at all times. To restore the laminations to their original condition, remove them from the wiper arm and apply several drops of glycerine to the surface, allowing them to soak in be- tween the laminations before wiping off any excess with a clean cloth. —A. H. Waychoff. Efficient Tube Repair Rack HE housing of an otherwise worthless auto generator can be converted into a handy tube repair rack. Discard all of the generator except the heavy casing and mount this to а block of wood measuring 12 by 12 by 1% inches. The completed rack is then screwed fast to the side of the garage, where it is ready for instant use. In making repairs to inner tubes the tube is hung over the rack, drawn tight with the foot and repair patch applied.—E. E. Swanson. ` HOLLOW INTERIOR USED TO STORE KIT, KNIFE,ETC. 90 Modern Mechanix

Page 91

Blower Keeps Drill Press Clean S" TURNED WOOD DISK PRESSED TIGHTLY ON SHAFT j| WHEN NOT IN әр USE SWING WHEEL d PF] AWAY FROM TES FRICTION DISK H~ BEND TUBE TO DESIRED SHAPE AND COAT WITH SHELLAC TO HOLD ITS SHAPE S/DE VIEW The blower attaches to the drill press upright by means of a clamped bracket, cut to the required dimensions from 34-inch plywood. А 5-inch fric- tion-drive wheel operates the funnel-shaped blower. by Dick Cole | DRILL-PRESS is a very versatile tool А. in a home workshop and besides per- forming its primary function of drilling holes, it can, with special attachments, be used for mortising, routing, carving and as a shaper. It is desirable in many of these operations that the chips be cleared away, particularly when a pattern must be followed, as in carv- ing. Here is a very efficient blower which can be made for a few cents. Nearly all of the current model motors, for home workshop use, have double shafts—that is, the shaft protrudes at both ends of the motor. In the case of a drill-press with a vertical motor, it is a simple job to fit a wood friction disk to the lower shaft-end, and have it turn a smaller friction wheel, such as the bobbin- winding wheel from an old sewing machine. This, in turn, is on the shaft with a fan con- tained in the funnel-like housing. A short length of flexible, metal tubing carries the blast of air to the job on the drill-table. All of which is very simple. The detail drawings show the general lay- December, 1937 Costing Practical] i ш y nothing to buil i E | о build, і : d blower whisks away chips, dust ает ee € as rapidly as they are PERAE ee { We MACHINE 5'— — (SCREW | 2? Wt А bel | | 7 HOLE TO FIT PEDESTAL SMALL HOLE IN SHAFT TO OIL BUSH SEWING MACHINE BOBBIN WINDING WHEEL He SHAFT BRASS BUSHING xd 4" FUNNEL == TWO BRASS NUTS "FLEXIBLE = = METAL TUBE FAN, OF 22 GAGE GAL.IRON | 60° CONSTANT PITCH LEFT HAND PITCH The blower housing is formed from a 4-inch funnel, fitted with a length of flexible metal tubing. Make the fan from galvanized iron to dimensions indicated. Holes drilled in the bracket provide for air intake. out, which, with minor variations, will meet the requirements of nearly any drill-press of the vertical motor type. Even in the case where the motor is a separate unit, the basic [Continued on page 132] 91

Page 92

by ЕЯ Mason Marcus ROBABLY the most discouraging factor to all embryo home chemists is the lack of costly equipment that is outlined as neces- sary in most experiments. The experiments described in this article are unique in that the only necessary equipment consists of a few test tubes, jars, a pan, and a teaspoon. Perhaps you are wondering what a col- loidal chemistry is all about. Colloidal chemistry is concerned with suspensions, emulsions, and all other phenomena of finely divided particles. Colloids are quite common in our every- day life. Milk is a colloid Steam, fog, ink, butter, and gelatin are aii colloids. The red of а beautiful sunset is due to the finely divided colloidal particles of dust suspended in the air and refracting the light. Some of Experiments in Ordinary household gelatin, vinegar, wa- ter and a few com- mon and inexpen- sive chemicals provide all materials for performing these novel experiments. these colloidal particles are so small that they cannot be seen in a regular microscope which shows particles in trans- mitted light but must be viewed in an ultra- microscope which uses a dark-field and the particles are seen by reflected light. There are two types of colloidal systems. One of these is a watery system and is called a "sol" The type that we are going to ex- periment with are called "gels" for they are in the form of a jelly-like substance such as the gelatin desserts which we eat. There is a beautiful phenomena in the chemistry of gels which we call rhythmic banding. These can be made in gels of gela- tin or of silicic acid. Beautiful bands of bright red and colorless can be made to ap- pear in an ordinary test-tube. All of these Rhythmic banding effects, as picture at left, are produced by mixing 1/2 tea- spoonful of water glass with 2 teaspoonsful of water. To this is added a few crystals of potassium iodide dissolved in 2 teaspoonsful of vinegar. When poured into a test tube a jelly-like mass is formed. Adding a solution made from a few mercuric acid crystals, will produce beautiful red bands. Below—Cross-section view of Liesegang’s rings formed from a solution con- taining unflavored gelatin, silver nitrate, or lunar caustic, and water. Modern Mechanix

Page 93

Anyone can perform these unique experiments in colloidal chemistry. The only equipment required is a few test tubes, a teaspoon, pan and several small bottles. experiments have a gel for a base. For the first experiment in which we get the red bands, we will use silicic acid for a base. Do not let the name scare you, for silicic acid gel is nothing more than а mixture of common water glass and an acid such as white vinegar. It can be made by taking lo-teaspoon of water glass which сап be purchased at any hardware or drug store, and mixing it with two teaspoons of water. This forms solution “A.” Solution “B” consists of two teaspoons of white vinegar or 5% acetic acid which is found in all vinegar and which gives it its sour taste. When solution “B” is poured into solution “A” a colorless solid mass is formed, known as pure silicic acid gel. It will be noticed that it is quite rubbery and will produce a metallic ring when the test-tube is tapped. To make the red bands in the test-tube, a few crystals of po- tassium iodide are added to the acid solution “В,” and then “В” is added to “A.” When this has set, which should require no more than a few seconds, a [Continued on page 130] December, 1937 This unusual ‘lead tree” experi- ment provides one of the most un- usual displays in colloidal chemis- try. In a small vial place V? tea- spoonful of water glass mixed with 2 teaspoonsful of water. Next dissolve a few lead acetate crystals in 3 teaspoonsful of white vinegar and add to the water and water glass solution. Insert a small strip of zinc in the vial and allow it to remain submerged for several days. Resulting effects are shown in these pictures. Top picture shows the "fead tree" after 2 hours while at left tree is shown after 24 hours. 93

Page 94

Hitching a Microscope А Мапу set-ups may be used in taking photomiucro- i graphs. Here a plate camera is supported over the microscope on a tripod, while blocks of wood elevate. the ‘microscope to correct height. Desk | 5 lamp" light source ato at the extreme left. HE mere inspection of bugs and other specimens under a microscope, or the making of permanent slides, is a fascinating pastime.. But photography through a micro- scope is something else and a job worthy of the most enthusiastic devotee and one of the most engaging of all hobbies. It must be admitted at the outset that photomicrography is probably the most difi- cult of all forms of the photographic art, assuming that perfection is the goal. But reasonably good pictures can be secured by the beginner within a week. Thereafter, as in any type of photography, improvement is a matter of skill gained by patience, care and practice. Of decided importance is the fact that con- trary to expectation, one does not need a lot of expensive equipment for this work. Any type of camera can be hitched to a micro- scope, and the accessories either purchased 94 The results obtained when a slide of human blood is photomicrographed are shown in the above series of pic- tures. Fhe first print made (1) showed lack of contrast. In the next, (2) orthochromatic film was used with a moderately short exposure. Results still were not satisfactory, so a longer exposure was given the en- suing print (3) with noticeable im- provement. The amateur expected better results and purchased a set of light filters. The first print was jarred during exposure (4) so an- other attempt was made. In realign- ing the lens, the condenser was moved slightly, resulting in an off- focus image (5), but the experi- menter finally triumphed with excel- lent photomicrograph of blood (6). a few at a time or made at home, according to preference. Naturally, the better the equipment, the better the results. But it does not follow that one should put off trying his hand at a few pictures just because his in- struments happen to be of the cheaper or eruder sort. Take some shots anyway and learn the rudiments of the game; it's loads of fun and good experience. Better pictures will then come more easily when a better outfit is obtained. Complete photomicrographie apparatus is commercially available at prices covering a considerable range. Some of the professional outfits run into elaborate and expensive de- signs that would appall the novice as much by their complexity as by their cost. Never- theless all of them, from simplest to most in- tricate, operate on a single, elementary principle that we can easily and quickly demonstrate. Roll up a cone of cardboard and tie or glue the overlapping edges, so that the smaller Modern Mechanix

Page 95

To Your Camera - by Julian D. Corrington, Ph.D. Photomicrographic | from. Wards Natura Science Est.. Inc. opening of the а wil fit snugly over the eyepiece of the microscope, the cone being inverted, base upward. This base should be some 10 inches above the eyepiece and from 4 to 6 inches in di- ameter. Paste a sheet of white tissue paper across the open base. With a slide in position on the microscope stage, and performing the demonstration at night in a darkened room, shoot as much light as possible through the microscope, se- cure a focus, and there is the picture of the object upon the tissue paper. This is actually a case of projection, just like that of the mo- tion picture or lantern slide projector. Now it is obvious that if we were to replace the tissue paper with sensitized film or plate, we should be able to make a photograph of the object in this same manner. And that is just what is done by photomicrographic December, 1937 _ Photographing microscopic wonders is a new and inter- esting hobby. — This 9x12 cm plate camera, attached to a home-made stand, makes excellent photomicro- graphs. A sheet of photo mount paper between camera lens and microscope eyepiece serves as a light-tight adapter. Black “scotch” tape will also provide effective results. which are no more than black cameras, boxes; the word “camera” means a chamber and a box is a miniature chamber. When hooked up to a microscope, all of the acces- sories of modern cameras may be dispensed with, since the microscope already has lenses for focusing, and exposures may be made by snapping the light source on and off, thus eliminating the necessity of a shutter. One of the best methods of building your own camera is to center the construction 95

Page 96

Owners of Gem mi- croscopes should con- struct a stand fitted with a slanting base so that specimen holder rests in a hori- zontal position. around a plate holder. Buy a 4x5 plate holder, new or used, and at the same time se- cure a 4x5 ground glass. Build a box out of plywood, pressed-wood, or similar material, glued or bradded to a wooden frame. At one end is the plate holder; at the other, a trifle less than 10 inches away, cut a round hole in the center, 3 inches in diameter. Two points should receive careful atten- tion: The plate holder must be accurately level when the camera is fastened to the stand, so that all parts of the image will be simultaneously in sharp focus; and the camera must be light-tight. The stand is that part of the apparatus which puts the camera in correct relationship to the microscope, and some of the accom- panying illustrations indicate the simplicity 96 This beginner’s photomicrograph of a plant stem section shows im- proper focus a poor contrast, А filter and longer exposure would have improved it considerably. with which a home-made stand may be con- structed. The base should be broad and flat and heavy to provide a firm support; the up- right should be a true perpendicular and of sufficient massiveness and rigidity of connec- tion to the base as to avoid all possible vibration. If the camera is a home-made box, as suggested above, it may be fastened per- manently to the upright so that the plate holder is accurately level and at such a distance as to be in approximate focus, as determined by trial for any given microscope. The exact focus is then secured by means of the coarse and fine adjustments as well as the drawtube, according to the type of instrument used. | A useful and time-saving suggestion is to find, once and for all, the correct position for the microscope on the base. Cut a sheet of plywood or very heavy cardboard to fit the base of the photomicrographic stand. Place this sheet on the base, then add the micro- scope and secure an accurate alignment by focusing the image of some slide mount on the camera ground glass, exactly as in taking a picture. This should be the permanent po- sition of the scope for all future exposures. Now trace around the microscope base with a pencil, jigsaw out the design, tack or glue the stencil thus made to the stand base, and thereafter merely insert the microscope in this receiving well Pivoted wooden cleats [Continued on page 142] Modern Mechanix

Page 97

SINGLE WIRE RUNS AROUND ROOM, -— {SEE PARANI TURN TRANSFORMER SLOWLY TO REDUCE HUM On early types of. a.c. "sets hum. is, produced by improper placement or shielding of the A.F- transformer between first and second stages. To overcome this, en- close transformer in copper shield can or turn it until the hum. “pickup: is minimized. SERIES HEATER > RESISTOR TO TUBE ye TSH ELLS December, 1937 The necessity for getting up to shut off the radio during an ad- vertising “blurb” can be elimi- nated by connecting the set in series with several button-type pendant switches. The switches can be located around the room in the manner shown above. The single wire connecting up the various switches may be tacked to the top of the base- · boards with staples so that its presence will not be noticed. TONE CONTROL 200,000 OHM POTENTIOMETER This simple tone, control can be installed on any set. Mount parts in a bakelite box, connect red lead to plate of output tube and black to chassis. If set uses two output tubes, connect leads to plate prong of each. 0.1 MFD. 400 V. RED The sensitivity of a.c.-d.c. sets can often be improved by shunting the condenser of the “floating ground” with a 0.25 megohm resistor as shown in the power supply diagram below. ы Pusu put tON PENDANT once gut PAINT INSIDE AN BL LACK TSIDE By painting both inside { and outside of rectifier shield сап with black paint; life of tube сап be lengthened. The раі absorbs heat and thus keeps internal tem- * perature of tube down. TO B+ LEADS TO CATHODES — CONNECT 0.25 MEG. RESISTOR HERE SLSR SES

Page 98

Faulty power lines are sometimes re- sponsible for the interference heard on sets. Power com- panies stand ready to track down troublesome lines. by Robert S. Kruse, E. E. T IS no good to plug a erack in a rowboat while water is pouring in through a 6-inch hole at the other end. In just the same way one cannot get quiet radio recep- tion with the best anti-noise device while noise is pouring in through some other gate- way—and there are 5 ways for the noise to get in. Let us examine the 5 gates, to see how they may be closed. Very many radio receivers, even when in good repair, are noise- factories on their own ac- count. 'These noises take the form of hums or "Shhhhhh" noises, which may per- : Broken light sockets, worn beating = pads, toasters and irons all tend to create noise that hinders reception, FS NOT NEAR ROO ef. v OR WIRES i PT = fe 40° то 80 Y П ORDINARY BROADCASTS == Described here are three types of noise reducing antennas. Two of о JOINT : them are designed especially for 30-40 n shortwave reception, while the third \ = is for broadcast pick-up only. All a SHORT Dee are available in inexpensive kit form. Mi ^ (ANTINO!S 19 ————— — | sist even when the antenna terminal of the set is connected to the chassis of the set. In other cases the hum is heard only when a station is tuned in, and still others the “shush” noise appears only on weak stations or when signals fade down. ; All these things are design-defects found | in both cheap and costly receivers. A really вага RELIABLE ANTENNAS ANTENNAS STATIC REDUCING ANTENNA 70! TO 200! ` Right—In localities where static is ex- HEIGHT 2‘ 70 6' cessive, an antenna located only a few т vue n т> feet аБоуе the ground will often re- 98 Modern Mechanix duce annoying radio disturbances. GROUND LINE

Page 99

A noise filter consisting of two choke coils and two condensers, connected as shown, will often reduce power line interference. good serviceman will understand what causes them and you may learn whether to trade in the set for a better one or have him make changes in its circuit to get rid of the noise. Sometimes the receiver can be made decently quiet if given a 100-foot antenna but if that seems to overload it, compromise with a 75-foot antenna. On Jack Benny's program, and in the funny papers, any fool noise is called "static," but December, 1937 How to check radio noise \ at its source. If noise persists when antenna is grounded to chassis, it is en- tering set through the power line. Natural static, as caused. .- ` by thunderstorms, cannot - -þe entirely eliminated: Special antennas will aid 3n partially reducing и. Sharp crashes of static may be reduced in some instances by connecting a G-10 neon bulb across the speaker transformer. there is no mistaking the real article when it has once been recognized. Static is infre- quent in winter and frequent in warm weather, especially after sundown. It never squeals or buzzes as the funny-men say, but is always and every time explosive in nature —a crash or pop for а single “splash” of static on a grating or frying sound but never a steady noise. It cannot be stopped at the source, for nature is responsible, but we can cover moderately strong static by using a larger antenna, as already mentioned, pro- vided we make the antenna merely longer —not higher. Broadcast reception can be made fairly acceptable with an antenna 5 feet high and 100 feet long when the ordi- nary antenna nearly ruins the speaker. Most people now know that pitched noises may be reduced by turning the tone control to “bass” or "low pitch" and accepting the [Continued on page 134] 99

Page 100

BUILD THIS TWO-TUBE AMATEUR SPECIAL’ by Clifford Peters HE “Two-Tube Amateur Special” will fill the wants of the future radio amateur, or the person who desires to listen only:to the short waves with all their interesting broad- casts. For the person who now is learning the code, this receiver will supply all the code practice desired. : Simple to construct, the entire outfit can be assembled and wired, ready to operate, during a weekend. А metal cabinet serves the double purpose of furnishing adequate shielding and giving the finished product an attractive appearance. The outfit was con- structed with the power supply as a separate unit to remove the possibility of a. c. hum pickup so predominant in many home-built regenerative receivers, using a power pack. Before starting the actual construction, the builder would do well to study carefully the wiring diagram and the placement of parts. Slight variation of parts placement will not materially affect the operation of the re- ceiver. The builder will notice that the two tuning condensers are connected in parallel. The .0001 mf. variable condenser is used for band- setting purposes, and the .000035 mf. con- denser, mounted near the center of the panel, for spreading the section of the band selected by the band-setting condenser. Although this receiver is not recommended for loudspeaker operation, it will furnish sufficient volume on some stations to be heard throughout the room. It will, in any case, give signals loud enough to be read with headphones. 100 Actual construction should start with the panellayout. A cabinet measuring seven by ten inches long and eight inches deep will be found to be most suitable. This cabinet should have a removable panel so that layout and drilling ean be done with it removed from the rest of the cabinet. The location for the band-spread con- denser was obtained by drawing diagonal lines from the corners of the panel, and meas- uring up one-quarter of an inch from the intersection of these lines. The centers of the holes for the band-set condenser and the potentiometer are ob- tained by measuring up two inches from the bottom of the panel and two inches in from each side. The pilot light and the “В” switch are located one and one-half inches from each side and two inches from the top of the panel. A plyboard subpanel measuring eight by seven inches deep is attached to the panel by three one-inch angle brackets. The sub- panel is mounted approximately one and a half inches from the bottom. Because the potentiometer and the band-setting con- denser are mounted only two inches from the bottom of the panel, it is necessary to cut sections out of the baseboard to accommo- date these instruments. It will be noted that the power supply is larger than most of those used for receivers. It can therefore be used with an amplifier for this receiver, or as a source of power for a crystal oscillator. The completed receiver as viewed from the front. “В” switch shows at the upper left corner of the panel. The pilot light is at the right. The panel measures seven by ten inches long. Modern Mechanix

Page 101

A switch is placed in the “B” plus lead so that the receiver may be shut off tem- porarily without turning off the filaments. When the receiver is used with a trans- mitter, this “B” switch will be found espe- cially useful If the entire receiver, in- cluding the filaments, is turned off, ap- proximately twenty seconds are required before the tubes are again at operating temperature. The “В” switch eliminates this time lag. The pilot light indicates that the receiver is turned on even though the “В” switch is turned off. Different values of grid leaks should be 6 K7 R3 ВЕСІ d 05000 GRID > — Са C5 = — o а» А = 2 Li < Е ce d ucl me нн — = = - eb Ri Ra A — де + = т AO 3 H PILOT LIGHT X sv Markings on all parts shown in the schematic diagram agree with those shown on photographs. тшшш» g = B+

December, 1937 TUBE BASE DIAGRAMS FROM BOTTOM OF TUBE OR SOCKET ° GRID САР 6C5 cT LS R4 y 7; © Ca Мы o RS — PHONES SCHEMATIC Note on photo that C1 and R3 are connected to detec- tor tube (6K7) through a grid cap at top of tube.

101

Page 102

COIL DETAIL L5 POWER TRANSFORMER BOTTOM VIEW OF COIL FORM iried if the set does not go into oscillation smoothly. Probably two or three megohms will be found to be the correct size. If your set is not troubled with tunable hums, it will not require condensers C9, C12, C13, and choke coil RFC2. If your trans- former does not have a center tap on the 6.3-volt winding used for the 6K7 and the 6C5, connect a 75-ohm center tap resistor across the filament at the detector tube socket. Connect the center contact to the ground. The two outside contacts are connected to the filament, one on each lead. Be sure that the rear of the panel is scraped clean where condensers C2 and C3 are fast- ened, As most metal panels are painted black at the rear, a poor contact may result if the panel at that point is not clean. Holes are drilled through the rear of the cabinet to make room for the wires to the binding posts at the rear of the set. Be sure that the wire used for connecting the set to the power supply is well insulated. The coils should be wound on four-prong forms measuring one and one-half inches in diameter. The winding should be spread out over a space measuring an inch and a 102 RECTIFIER 80 6.3 V Above is shown the schematic diagram of the power supply. Condensers C9, C12, C13, and RFC2 may be omitted if the receiver is not troubled with tunable hum. Below is shown the completed receiver with its power supply. power unit is kept several feet from the receiver. shown under the base. The connections for the tuning coil are shown at the left. No provisions are made for turning the power supply on or off; this is left to the builder. Probably the simplest method is by pulling out a. c. plug or by a switch in the line itself. During operation be sure that the The 40,000-ohm bleeder resistor is No. quarter to an inch and three-quarters. 22 or 24 D.C.C. wire is used for the wind- ings. The tap for the cathode is counted off from the ground end of the coil. Although the following specifications were found to bring in the various amateur bands at the correct points on the band-setting condenser, the builder may find that а few more or less turns will be required. Total Cathode Frenquency turns tap turns 1715- 2000 kc. 58 4 3500- 4000 ke. 29 1% 7000- 7300 ke. 14 1 14400-14000 kc. 9 34 Be sure to solder all connections, The greatest help in doing a neat soldering job is a well-tinned iron. When the set is com- pleted and ready for testing, examine the wiring once more to be sure that all connec- tions are made to the correct points and well soldered. The connections marked “Sh” in the socket diagrams are connected to ground. After the set is turned on, a click should be heard when the potentiometer is turned past the point of oscillation. With the poten- tiometer turned just past the point of oscil- [Continued on page 144] Modern Mechanix

Page 103

Ba in us H 1 i dB ui ean No, they’re not quadruplets, but one and the same man! This picture, taken by Calaway Moore of Swainsboro, Ga., eatned this month’s $15 award. The shot was made by expos- ing only one-quarter of the film at atime. The lens aperture was stopped down to f. 11. MONEY FOR YOUR PICTURES! Get busy with your camera and send in unusual pictures of people, animals, machines, trains, airplanes, etc, Each month we will pay $15 for the best pic- ture received from readers, $10 for the second choice, and $5 each for the next three selections. Prints should be glossy, as large as possible up to 8x10 inches (although a small, clear photo is more desirable than a big, fuzzy one) and should be accompanied by the following data: make and size of camera, type 'of film, and how developed and printed, lens opening and shutter speed, and lighting conditions. Wrap all prints carefully and include postage if you want them returned. Address all con- tributions to Photography Editor, MODERN МЕСНАМІХ, 1501 Broad- way, New York, N. Y. Though the picture at right is a photo oddity, it brings out an important point that should not be overlooked by the ama- teur photographer. Don't get too close to the subject if your camera has a short focus lens, otherwise a distorted shot will result. For this picture, Emil Pearson of Redgranite, Wis., received the .$5 fourth award. December, 1937 Sunset scenes like this one always make interesting addi- tions to the photo album. Fifth award of $5 was given to C. Edward Zeller of Westmount, Que., for his interesting photo. 'This unusual wide-angle pic- ture was taken with a Graflex by Ivan R. Tomkins of Savan- nah, Ga. Close examination will reveal that the image is a reflection from the hub cap of an automobile wheel. For this photograph, Mr. Tomkins received second award of $10. Fireworks displays are always excellent sub- jects for unusual pictures. This photo, taken with a f. 4.5 lens and 1/25 second exposure, earned for Bruce Pendlebury of Moose Jaw, Sask., Canada, third award of $5.

Page 104

Page 105

Кк ж P ‘Your бит. Holiday Cards | m B å * А small camera and simple props provide all equipment needed to make these clever greeting cards. Simplest of all to make, this card is never- theless very effective. A lighted candle, pen, inkwell and evergreen twig provide a cheery setting for the friendly Yuletide greeting. making this, the table was first covered with a layer of news- papers, and the “aurora” back- ground, of dark colored cardboard with the designs painted on it with white ink, set in place. A half inch layer of flour was then sifted over the paper covered table top and a small pile made where the “North Pole” was to stand. The pole, by the way, was nothing more than a large peppermint stick as sold in all stores at Christmas time. Santa, his gifts, in a homelike setting, was made with [Continued on page 128] the same window and wall background, but with the use of an additional doll character. The toys used to decorate the tree were a tint chair from a set of kiddie’s doll furni- ture, supplemented with a striped whistle and a few marbles to look like balls. Light- ing for this scene is the same as that used in the first except, that the lamp was moved a bit farther to the left, so that more sharply defined shadows are cast. In the North Pole scene, we find old Santa, himself, about to leave on his yearly round, while the Aurora shines brilliantly around the North Pole. This scene took but a little i over an hour in the making and photograph- Bits of tinsel, an evergreen twig, a doll chair and a В с рат of china character dolls are incorporated into Ing, and proved to be one of the favorites this original greeting card. The window frame in the background is formed of black cardboard and thin strips of wood. Star and snow effect are painted in. December, 1937 : 105 with the children to whom it was sent. In

Page 106

. {кшш DvrLorING “POUR DEVELOPER — , N BERE Cm HORT PIECES OFC iD Y 1 ELLULOID X. 3 2 D e | LACQUER ALL PARTS BLACK In order that the developer mix thoroughly when poured into the tanks and all light shielded from solution, the lids of the develop- ing tanks are fitted а de with baffles made as an borsh де shown in the above his ak ү for phantom detail. The baffle is cemented to signe” cut ^ spacet? the lid on short cellu- raking г the fu {гозер loid tabs. The fun- пов © enplish Cotone ERR nel, on top is ce- js cern, of à ge nata mented with acetone. Бе А $n an men Pictured at right 1s a com- pleted roll fim tank, loaded and ready for the developing solution. Ál- though shown transparent, the tank when in actual use should be given one or more of black lacquer. OST professional photographers develop T: qe their negatives by the time and tem- o insure tank rigidity. E the bottoms are fitted perature method in a tank, to assure results popup eod аа with . that are uniform from day to day. A high p. e e ed average of good negatives is one of the secrets ith acetone cement. of the successful photographer. When the : amateur wishes to follow this method, how- ever, quite often he is confronted with one or more problems. First, a suitable tank may be too expensive. Again, one of the right size, particularly for roll film, may not be available. Finally, if you wish to make your own tank and are lucky enough to have a skeet of non-corrosive metal, such as monel or stainless steel, it is difficult to put to- gether. Solder cannot be used, as it would contaminate the developer. Heavy sheet celluloid, which you can pur- chase at any auto supply store, is the ideal answer to the problem. It is not expensive, does not affect the developer and can be welded together easily. Hold two pieces to- gether lightly and touch the edges with a drop 106 Modern Mechanix

Page 107

Tanks Are Easy To Make Though inexpensive to make, the celluloid developing tanks will be found superior to many com- mercial types. The photo above shows a cut film tank in use. Below——When winding roll film on the developing tank spool, squeeze the edges of the film. as it is wound up, so that it bulges sufficiently to permit its insertion in the film tracks. of acetone. Like a flash the latter penetrates and makes a secure, waterproof bond. The illustrations show how to make tanks for developing either cut film, film packs or roll film. The roll film tank is supplied with a celluloid spool on which the film is rolled for development. December, 1937 by Kenneth Murray Spiral strips of celluloid are ce- mented to the inside of the spool so that the surfaces do not contact each other during the developing process. Note holes in upper disc for developer to pass through. Make these with a small machine drill. A rubber bulb circulator inserted in the cut film tank insure the de- veloping solution of proper agitation at all times. Roll film is agitated by gently shaking the covered tank. First cut a piece of thin plywood to the desired size and shape for the bottom of the tank, then bend a sheet of celluloid around it to make the sides. Cover the plywood with a piece of celluloid of identical size and flow acetone along the edges so that the two will be bonded to the walls. This forms the real bottom of the tank and protects the plywood from moisture. If the tank is large it is advisable to reinforce the corners and edges with additional strips of celluloid, welded in place with acetone. In the case of the cut-film tank, bend nar- row strips of celluloid and weld them in orderly fashion on either side, with acetone, to form troughs or grooves into which the [Continued on page 136] 107

Page 108

With the equipment arranged in this manner, contact printing is easily accomplished. If desired, | the glass bowl used for the acetic acid shortstop bath may be re- ... placed by another 5 by 7-inch tray. ecd ULL instructions for developing roll film at home were given on pages 104 and 105 of the November issue of Морекм MECHANIX. The next operation is "printing," which is the process of producing actual black and white pietures on paper from the developed nega- tives. There are two kinds of photographic "printing"—contact and projection. In con- tact printing, the negative is placed directly against the surface of a sheet of sensitized paper while light is flashed through the nega- tive so that it hits the paper directly. The size of the resulting print is thus exactly the same size as the original negative taken by the camera. In projection printing the negative is placed behind a lens in a sort of lantern, and the image is thrown onto sensitized paper a short distance away. By proper adjustment of the optical system, the print can be made many times larger than the 108 How To PRINT Anyone can » make snapshot prints. These © instructions tell how it is done. | original negative. This form printing is com- monly known as “enlarging.” The person just beginning in photography should learn contact printing first, as it is very simple and requires only one very in- expensive and easily-made instrument — a printing box. This is a plain box, constructed of three-ply veneer or pressed wood, with an electric bulb in the bottom. The top is left open to accommodate a “printing frame,” a device for holding the negative. and the sensitive paper firmly and evenly together. You can make such a box in less than an hour if you follow the accompanying plans. The dimensions shown are for a 4 by 5-inch printing frame; that is, а frame that takes negatives up to 4 by 5 inches. This is large enough for all standard roll or film pack negatives in the popular amateur sizes. An opening in the center of the glass, to take your particular negative, is easily masked Modern Mechanix

Page 109

off with black “scotch” tape, which costs only a few cents a roll. In making the box, be sure that the print- ing frame fits loosely over the top, so that it can be put in place and removed quickly. Besides the printing box, the following: items, all obtainable at very reasonable prices from any photo supply house will be needed: an *OA" yellow filter for the darkroom safe- light; several fresh tubes of “MQ” developer; the same hypo saved from the negative de- veloping process; a one-pound bottle of acetic acid; two trays, one 5 by 7 and the other 8 by 10 inches; a few glass bowls or shallow jars; a wooden clip or pair of tongs for han- dling wet prints and a supply of contact paper. As a starter, get one envelope each of Azo E-4 and E-2 paper. This is semi-matte paper, the first of "contrast" grade for flat negatives and the other “normal” grade for normal negatives. This material is surprisingly cheap and therefore permits a lot of experi- menting. Half fill the 8 by 10 tray with hypo. Mix the MQ developer as per its label for con- fact prints and put it into the 5 by 7 tray. The printing box is of simple plywood construction, made to the dimensions given in the detail at right. A cleat socket, fitted wth a 25-watt bulb, is mounted in the bottom and wired to a radio toggle switch and a length of fixture cord. Printing frame fits on top. December, 1937 Your Own Pictures| Measure out 34-oz. of acetic acid, mix with cold water to make a pint of liquid, and pour into the flat bowl or, better still, into another 5 by 7 tray. Last, fill the tall jar with plain water. The arrangement of apparatus as shown in the large picture is a convenient one. To commence, darken the room and turn on the safelight. Don't be alarmed by the bright- ness of the yellow light. Photographie paper is much less sensitive to light than negatives, and can be handled in perfect safety under the “OA” filter. The ability to judge the "contrast" of nega- tives will come only with experience. Nor- mally-exposed negatives, which have been developed in MQ developer, usually take “normal” grade paper; therefore start with that. Open the printing frame and clean glass pane carefully with a soft handkerchief. Place the negative on it, with the dull (emul- sion) side up. A sheet of Azo paper is then laid evenly over the negative, with its chemi- cally-treated side against the latter. By ex- amining the paper under the safelight, the [Continued on page 142] — DETAIL OF PRINTING BOX — | PLYWOOD STRIPS TO SUPPORT PRINTING FRAME TOGGLE Sf SWITCH. oof 109

Page 110

Three narrow strips of wood, each fitted with sharpened mail prods, provide a handy means for extending the legs of a tripod. The strips are attached to the regular tripod with small “С” clamps as is illustrated at left. L-shape cardboard boarders, like the one shown at right, are excellent for determining the correct amount of trimming a print requires, in order that it shows up most effectively. Once determined, it is an easy matter to mark the print with а China marking pencil and trim it down to correct size. Left——A 21 v. flash- light bulb and bat- tery, connected in series with a photo- flash lamp, will in- stantly tell its condi- tion. If 21% v. bulb glows, photoflash lamp is in working condition. Below—An ink that will chemically re- act with a photographic print so as to produce a lasting white signature is easy to make. First dissolve 20 grains of copper sulphate in 2 oz. of water, then add 10 grains of sodium chloride (com- mon salt). When this dissolves, add sufficient ammonia to turn it a clear blue color. Finally add 10 grains of | sodium hyposulphite (ordinary hypo"). | Apply ink to photo with a gold pen. | Above — Where the darkroom facilities аге too cramped to permit drying of film by sus- pending it from a long cord, this clip holder will prove extremely useful. Several spring clothes pins are threaded on a length of iron wire in the manner shown. The end clips may be attached to a chair with the center clips serving to suspend the strip of wet film. Right-—Amateur photogra- phers who take their pictures with a box camera can be sure of level "shots" by equipping the camera with two small spirit levels, The levels are nothing more than automobile fuses partly filled with alcohol or red ink, sealed and attached to the camera with cellulose cement. If old fuses are not available, short lengths of glass tubing, plugged with small corks, may be substituted. 110 Modern Mechanix

Page 111

A length of linen fish cord, fitted with a wire hook on one end and knotted at 1-foot imn- tervals, is excellent for mea- suring distance between lens and subject to be photographed. By removing the socket and shade from a flexible desk lamp it can be fitted with a reading glass so as to leave both hands free when ‘spotting’? print blemishes. An ordinary portrait lens can be used for wide-angle work. Fo- cus images on a ground glass screen and fit camera with a new. dis- tance calibration as shown at lower right Where the celluloid backing of a negative is stained or scratched, the emulsion can be saved by application of acetic acid to backing. Attach negative, emulsion side down, to a glass plate with rubber cement. After backing comes off, remove emulsion from plate and wipe off all rubber cement. Below——This useful hand reflec- tor consisis of a desk lamp shade and socket fitted to the wooden handle and threaded copper tube of an old electric soldering iron. Light is provided by a No. 1 or No. 2 size photoflood bulb. Very often the presence of small scratches on the surface of a cut-film negative can be attributed to the action of the finger nails from attempting to lift it from the developer. То overcome the difficulty, place a glass rod in tray as shown. The rod will elevate the negatives and permit easy removal. December. 1937 111

Page 112

: Seven iiti of this - freak egg were sold - for $26 to а news- syndicate “paper ‘HIS camera business gets into your blood. - No matter how good the last roll of film may turn out, you say to yourself, “This shot is undertimed. That one is over. I got too much scenery in this one. Boy, next time will be different!” Not long ago, three men got sodidten for an evening. All were interested in pho- tography. Two were amateurs, the third a commercial photographer who had a great outlay in equipment. No matter what the shot, he could get it. One of the two alleged 112 This homemade corn stalk cutter would not appeal to the average mewspaper reader, but a photo and short article on its construction resulted in a $10 check from a mechanical magazine. Left—A fast lens is needed to catch action pictures of home- built devices such as this trapeze ring-bar. amateurs was not actually that in the strict sense, because for years he had been selling prints to magazines and newspapers. Yet the commercial man regarded him as such be- cause he used a small folding camera which cost perhaps $30 when new. The third man owned a camera, too, though all he had was expense, and was about fed up because, while his pictures were usually good, he failed to find any market for them. Now here’s the odd part of that meeting. It came out, after much talking, that the first amateur who was selling an occasional pic- ture to magazines was getting more for his prints than was the commercial chap using an 8x10 camera. The reason was simple. A great many magazines, including the one you Modern Mechanix

Page 113

_ Newspapers and magazines ате constantly seeking new and novel pictures. Here is . how you can supply their -wants and also be paid well. are reading, pay $3 or more for pictures with a story to tell. Often an idea, photographi- cally shown and with a short, but accurate description, having two or three pictures in- cluded, will bring a $10 check, or even more. But, lest they be overlooked in the rush for stamps and envelopes, there are a few buts and ands which are mighty important. Pic- tures of the kind that sell must convey a specific idea and must also be in sharp focus, December, 1937 In spite of the excellence of this picture, it would be hard to sell alone. Accom- panied with a story on fishing, it would have the interest needed to sell it. a. This picture, showing the engine which supplied power to a midget auto, proved to be the keystone of an entire set of con- struction pictures. It sold the story! Left — Two photos of this mode! train layout and a detailed cap- tion earned $7 for an ambitious photographer. and on glossy paper. The larger the print the better of course, but in known instances, an old Brownie, taking a 34х55 print that cost $4 second-hand, earned over $2,000 in less than two years for its owner. The prints averaged $3.48 each, proving that the size or quality of the camera isn’t so important as knowing what kinds of pictures will sell and to whom to send them. [Continued on page 138] 113

Page 114

CALCULATOR CARD A new convenience for photographers is this photo-flash calculator card, which is small enough to be carried conveniently in the vest- pocket. In use, the inner sliding board is set for distance between subject and bulb and the correct diaphragm openings for the vari- ous shutter speeds read on edge of card. uet PHOT! ch a Jock letters, эш Bioful in creat They serve а st ts events c hic title page? “ijy groups, SpOTÉ SOL pones pictures, fomite Ge pictured. above TITLE BOARD SET UP AS SHOWN ABOUT 3! FROM n TINSEL FOIL LAID OVER RUBBER CEMENT Amateur movie fans will appreciate this sparkling film titling board, especially if they use Kodachrome films. It con- sists of a plywood board, 13 by 17 inches, to which are attached, with rubber cement, strands of multi-colored Christ- mas tree tinsel. When the cement has dried, the letter- ing is applied over the tinsel and the board rested at an angle to reflect the rays of a nearby, floodlight. 114 O"BOOK PLATES, PAPER CLAMP LIGHT SUPPORT a m Negatives of favorite snapshots will make excellent bookplates for home library volumes. The in- scription is lettered on tracing cloth with ink, as shown in the upper detail sketch. Attach cloth to film with rubber cement and print in usual way. OVER CHAIR A photoflood lamp that can be conveniently attached to a chair, table or any other object can be made by secur- ing a light socket to a large size paper clip with a 3%- inch nipple and nut. Cut two pieces of 14-inch rubber hose slightly longer than the clip's jaws, slit them down the center and tie or cement over the sharp metal edges. The socket is fitted with a collapsible shade to complete lamp.

Page 115

\ when you 5 Ride c 1938 HARLEY-DAVIDSON Thats right! The snappy new 1938 Mod- els are always "rarin' to go." And with one of these Harley-Davidsons you sure can pack every spare hour with pleasure —alternoons, evenings, holidays and va- cations. So decide now that you're going to OWN a Harley-Davidson. , . The new 1938 Models have the power, zip and ae - з x Harley-Davidson wins all. four stamina to “go places” with real class. 1937 National Hillclimb Cham- New streamlined style and advanced me- pionships at Muskegon, Michigan. chanical features make them “tops” in Above: Hap Seamans, 45 and performance and ride value—with new 80 Class “B National Champion 1 — Harley-Davidson mounted. “lows” in mileage cost. See your nearest Harley-Davidson dealer NOW for a FREE RIDE—ask about his Easy Pay Plans — and send in the couponl HARLEY- _ рлмірѕом When Answering Advertisements Please Mention December Modern Mechanix 115 поне"

Page 116

In this department the Photography Editor will answer any question or problem relating to cameras of all types, enlarging, printing, developing, taking pictures, and ihe vorious 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 nol permit publication of the question on this page. Send all inquiries to the Photography Editor, Modern Mechanix, 1501 Broadway, New York, N. Y. SELF-TONING PAPER In various photography manuals I have seen references to self-toning paper. Can you tell me what it is and how it is used?—Verrel Blythstone, Tampa, Fla. ‚ Self-toning paper is a special type of printing-out paper in which the emulsion contains a certain amount of gol necessary for toning. The image is printed-out, usually by daylight, although strong sources of artificial light such as an electric arc or mercury vapor lamp may be used. The prints are washed for a few minutes in water, then fixed in an ordinary fixing bath, Tones ranging from sepia to purple are produced according to the amount of washing. Self- toning papers are not very popular in America because they require strong daylight exposure and a negative of good quality with rather more contrast than required for ordinary printing papers. PART OF FIXING BATH TURNS MILKY= PART DOESN’T A part of the fixing bath which I made up recently turned milky, while that which was left standing in a tray, after fixing about a dozen prints, didn’t. To what might be attributed the cause of this?— George Exeter, Patterson, N, J. The precipitate, or milky coloring, appearing in the fixing bath consists of sulphur. It is due to too much acid, the use of insufficient or impure sulphur, or an excessive bath temperature, The temperature should not exceed 70? F. The reason for the used bath remaining clear was due to the neutralizing effect of the developer, carried over to the fixing bath by the prints. PLATINUM PRINTS AND HOW THEY ARE MADE Not long ago I was shown some prints by a friend who Said they were on platinum paper. Сап you tell me what they are and how they are made?—Vera Tanfford, Upper Darby, Pa. The Platinotype Process now in general use was invented by an Englishman, Willis, about 1875. The paper, which is available commercially from a British film manufacturer, is coated with a light-sensitive salt of iron and potassium chloroplatinite, When exposed to light, the iron salt is reduced, forming a faintly visible image. The paper is then placed in a solution of potassium oxalate, which reduces the platinum salt in contact with the image to metallic platinum, thus producing a highly stable image of pure platinum. The iron salts are then removed by placing the prints in a weak solution of hydrochloric acid, after which the print is washed briefly and dried. Despite its absolute permanence, this process is very seldom used, due to the high cost of materials and its limited application only to negatives of ihe highest quality contrast. HOW TO DETERMINE FILTER FACTOR I have a yellow filter marked 2X. Does this number in- dicate that an exposure twice the length of the usual ex- posure be required with Verichrome film?—Robert Hen- dricks, Seattle, Wash. The increase in exposure required when using a lens filter depends not only on the filter itself, but on the film with which it is used, and the light source. While the factor should be approximately two, with the film mentioned, it шау be more or less. 116 You can determine the factor, with sufficient accuracy for practical purposes, by making a series of exposures оп а gray object, with and without the filter attached to the camera lens. Ап excellent test can be made by copying a black and white photograph, first with the filter and then without it. With several exposures, you can determine the ratio required to produce negatives of the same general density. ECONOMICAL MEASURES WITH DEVELOPERS NOT ADVISED If I were to dilute a standard developing solution with an equal part of water, will pictures develop in twice the usual time required? Is this economy measure advised when one has plenty of spare time at his disposal?—Henry Green, Toronto, Ontario. - The time of development with ordinary developers, ех- cepting glycin, is not directly proportional co the dilution. While it might be possible to obtain satisfactory results by increasing the developing period, the time required, would be greater than twice the time necessary for developing under normal conditions. As developers are inexpensive the “try and hope” method is not advised. CAUSE FOR LINES ON NEGATIVES During the summer months I developed several rolls of film and found that a fine network of lines appeared on some of them. To what might be attributed the cause of the lines: appearing? — Allison McDonald, Vancouver, B. C., anada, The effect to which you refer is known as “reticulation” and is the result of sudden swelling or contraction of the gelatine film. To prevent this from happening again, keep the temperatures of the processing solutions and the water bath as nearly uniform as possible. Use a moderately rapid developer, fresh acid fixing and hardening bath. Avoid excessive washing if the water supply is warm, and dry the negatives as rapidly as possible in a current of air. HOW TO USE ONLY PART OF A CONVERTIBLE LENS 'Y have a convertible Kodak F. 4.5 lens. When using the front element alone, should I put it in the back or leave it in front of the lens housing?—Edward Johnson, San Ane tonio, Tex. The proper position for a single element of a convertible lens, when used alone, is behind the diaphragm. This posi- tion is correct for light rays reaching the concave of the lens first. MODERN MECHANIX AWARDS $40 EACH MONTH FOR BEST PHOTOS SUB- MITTED BY READERS The editors of Modern Mechanix will distribute $40 in cash awards to the five persons who, in their opinion, submit the best pictures suitable for publi- cation in the Modern Photography section. Full par- ticulars regarding these awards will be found in this issue on page 103.

Page 117

Imevical fastest powing hobby NAPSHOTS at NIGHT 1. Load your camera with Kodak “SS” Film HERE’S FUN for the whole family in snapshots at night. Baby in his bath... the older children with their pets... grown-ups at the piano... every- body enjoys the “shooting.” And you, most of all—for you’re snapping those intimate family pictures you’ve always wanted, never hoped to get. You don’t need an expensive camera for snapshots indoors at When Answering Advertisements Please Mention December Modern Mechanix frst do Wis. 2. Use two or three Photoflood lamps in Kodak Handy Reflectors night—not any more. Any cam- era that can be loaded with Kodak “SS” Film will do the trick—even the simplest Brownie. With “SS” Film, you use two or three of the new No. 2 Mazda Photoflood lamps, which last for hours, in the inexpensive Kodak Handy Reflectors. If your camera has an f.6.3 or faster lens, then No. 1 Photoflood lamps are powerful enough. FREE BOOKLET... Suggests а variety of picture opportunities... shows you how to arrange your lights... how to place your subject... tells you everything you need to know about two ways to make night pictures—snapshots with Photo- flood lamps, fast exposures with Photofiash lamps. (You can use Photoflash lamps, each good for one picture, if your camera can be set for "time.") Get а copy at your dealer's . . . Eastman Kodak Company, Rochester, N. Y. 117

Page 118

Underground Airport Radio Beacon Aids Blind Landings А new radio landing beam that emerges from an underground pit and holds great promise for mak- ing blind landings of airplanes practical and safe in foggy weather has been revealed by two Na- tional Bureau of Standards scientists, H. Diamond and F. W. Dunmore. The transmitting antenna is placed in a special subterranean compartment under the center of the landing field instead of being erected danger- ously in the air at the edge of the field. The Bureau of Standards’ scientists had their pre- liminary work done and ready to report two years ago but the interest of another govern- ment bureau delayed the scientific announce- ment. About six years ago the same group of govern- ment scientists developed a radio beacon system for aircraft landing fields which was so effective that after demonstrations in this country it was adopted and put into extensive use in Europe, Japan and Russia. It has not been installed as regular equipment on American landing fields, however. The new pit antenna improves this radio land- ing beacon. In the landing system, the airplane glides down a path that is marked by equal strength radio signals indicated on a convenient dial on the plane's instrument panel. The way that radio waves travel from the transmitting antenna makes this system possible. One kind of wave goes directly from the antenna to the plane, while another goes from the transmitting antenna to the ground and then is reflected to the plane. The interference of these two waves plus decreasing distance combine to enable the pilot to steer his craft along a radio path to a happy landing even if he can not see the landing field. When the transmitting antenna is in the air at the field's edge the path of the landing glide is а little too flat. Now the pit antenna gives a steeper and more satisfactory approach path. A further advantage of the underground system is that it can be built on a turntable and swung around to conform to wind direction, thus allow- ing landings to be made from any direction with the aid of only one antenna. Previously several antennae at the edges of the field were necessary. New Use For Old ‘Squeegees’ QUEEGEE plates, which have become too dull for further use, can be converted into serviceable developing trays for processing large prints. Bend up the sides and ends of the plates so that the tray attains a depth of about 114 inches. Do not cut the corners of the metal, but rather fold them over to form a flat-type waterproof joint. 118 Franklin Institute Aids Amateur Star Gazers Г IS highly possible that Philadelphia may some day boast of an amateur astronomer discovering a new comet, star or nova, ac- cording to James Stokley, Associate Direc- tor of The Franklin Institute in charge of Astronomy. > For the past few months Mr. Stokley has been welcoming many amateur astronomers to the Institute, where, under the supervision of expert amateur and professional students of the stars, they have been grinding tele- scope mirrors and building instruments with enthusiasm. t “The Institute,” said Mr. Stokley, “has set aside a complete workshop for these amateurs where they may spend all the time they wish. Dozens of telescopes are now in the course of construction. Periodic visits to the Fels Planetarium and the fine public Observatory of the Institute serve to bring the average layman closer to the majesty of the heavens. “Amateurs in astronomy," continues Mr. Stokley, "are contributing invaluable ma- terial toward the furtherance of this science and are also rendering much important aid and information to the professional. There is definite work to which thousands of amateurs contribute their observations. This is prin- cipally in keeping an almost continual watch over the variable stars which are always changing in brightness. “The professional astronomer must neces- sarily confine his attention to certain par- ticular phases of the science, but the amateur is better able to watch over broader areas, and thus, when anything unusual, like a new star or a comet occurs, he may notice it before the professional. Thus, Peltier has con- tributed five new comets and a new star in little more than ten years, and a few years ago a Japanese melon patch worker in Cali- fornia found another comet. This requires a very thorough knowledge of the constella- tions and the stars and other objects in them, so that anything strange may be recognized at once.” Air pressure on the body of an average sized person amounts to about 14 tons. The moon gives off no light of its own, but it reflects light from the sun which travels to the earth in a little over a minute.

Page 119

YES-THE WHOLE CROWDS COMING TO MY PARTY... 'CEPT JACK EVANS : wee HE'S NOT MUCH BUT JACKIE, ALL THE FELLOWS CAN | “DO THINGS” BUT YOUR eee HELEN LIKES “SACK EVANS...WITH 3 ЭТОУЕЋ 5000 VOTES- | WINS FIRST PRIZE — HELEN DIDN'T £ LE EVEN SAY HELLO! ^? GUESS 1 DON’T ER GET ASKED TO DERE PARTY. ‘WELL, MAY AS WELL 4 PRACTICE UP FOR AMATEUR HOUR. JACK EVANS! AND 1 DIDN'T EVEN INVITE WHY JACK EVANS! - YOU WERE WONDERFUL! WE ALL HEARD YOU LAST NIGHT... CONGRATULATIONS! .. |M HAVING ANOTHER PARTY NEXT WEE COME ...WI К AND I WANT YOU TO LL YOU HELP ME ROUND UP THE BUNCH?... AND BE SURE Е BRING o Boys and Girls s are good Harmonica players are always popular—always in demand at parties and “get-togethers”. Don't miss good times. Learn to play the Har- YOUR HARMONICA: ! a monica. It’s so easy with the new Hohner M. HOHNER, Inc., Dept. 18M I Instruction Book. Just mail the coupon for 351 Fourth Ave., New York City П your Free copy. Pl d , 1 ion Book FR Г] M. HOHNER, inc, 351 Fourth Ave., New York ease send me your new Instruction Boo EE. 1 [| "pÁD————À A ( EE [| [| Address „әш... ————————' A GÓ I L| r [| Сылнын ишнен ныды riri Hte нанава еван State... seen П Address Canadian inquiries to Hough & Kohler, Ltd., Toronto - When Answering Advertisements Please Mention December Modern Mechanix 119

Page 120

Iceboats Quadruple Speed! [Continued from page 49] the first puff of a 10-mile breeze propels the boat at that speed. The second 10-mile puff doubles the speed after the craft receives full benefit of the first blast. The third 10-mile puff increases the speed to 30 m. p. h. A craft of racing type can advantageously utilize another puff to hit 40 m. p. h. Air resistance, or windage, is the first of two factors that allay the assumption that craft could indefinitely multiply the wind's velocity. For that reason the speed ratio is limited to a 4 to 1 ratio. The second factor is weather ability, that makes performances in 40 and 50-mile winds for seem- ingly potential 150 and 200-mile gaits impossible. Of course, in moderately high winds, the speed of ice craft increases correspondingly; 20 and 30-mile wind velocities cater to 60 to 90-mile marks. Craft that are eligible to the 4-1 ratio in light winds can't safely be eligible in near gales. Although wind limitations govern the fre- quency of 90 m. p. h. speeds, heavy weather racing machines capable of doing four times the wind have hit the 124 mph. mark in rare instances. Such is the Debutante III, reputed to have traveled the fastest mile on ice at Kull Lake, Mich., in 1922. In a burst of speed, she hit 124 m. p. h. The 4 to 1 ratio is applicable to only the latest types, which embody sail efficiency and scientific improvements. Lightness is-the keynote of their construction, with the mast, booms, runnerplank and backbone of hollow construction, like the bones of a bird. In selecting an iceboat, to build or buy, choose one with streamlined (oval) mast and tear- drop runnerplank, if speed is desired. With streamlined features, the craft possesses mini- mized resistance and higher speed possibilities. See that rigging is of thin, powerful airplane cable to reduce windage; heavy shrouds and hull stays, slow the boat down noticeably. Check the alignment of the runners. Unless they are true fore and aft, with front and rear ends equi- distant, a drag will result. Sails should be efficiently cut, with proper draft, to furnish the utmost driving power. To prevent leakage and loss of vacuum, use only closely woven Wamsutta cloth. By experimenting with the tilt of the mast, the amount of rake needed io make tbe craft sail fastest can be easily determined. It should be remembered that the rake should always be aft. Germany had 172,000 workers employed in chemical industries in 1933; in 1936 the number had grown to 220,000. Cotton fabric is almost as important as rubber in making most automobile tires. 120 Advance Showing—1938 Cars [Continued from page 35] and ease of handling. Silence and freedom from vibration are achieved in higher degree than ever before, and less-frequent attention to lubrication is required. The most important changes are those tending to make gear-shifting easier. In many cars the gear lever has been removed from the floor and replaced by semi-automatic systems which make use of finger-levers situated either on the dash- board or just under the steering wheel With the hand-brake lever replaced by under-dash handles, the floor of the driver's compartment is left without obstructions, and the front seat now accommodates three persons in comfort. Transmissions have undergone many changes aside from the shifting device, and several of them include automatie overdrives which are designed to reduce engine speed and increase fuel economy at high rates of travel. Aside from bolder treatment of radiator fronts, no radical changes are noticeable in outward ap- pearances. Corners are nicely rounded, but little departure has been attempted from conventional shapes. "Tear drop" and similar freak designs, which did not receive popular support in past sea- sons, are entirely absent. The Mechanical Dinosaur [Continued from page 55] arm travels an electric dump car. Another big dragline fills the dump car, which then speeds off and dumps the dirt by remote control The enormous "bird" can tramp along the bank, spreading dirt wherever needed. Out in the Arizona desert, government diggers ran into patches of gravel stuck together so hard with natural cement that it called for blasting. But an engineer designed a huge steel hook twenty-seven feet long, with an eight-foot crook that reaches out under a patch of gravel and exerts a powerful up-leverage. This ten-ton "fish-hook" quickly broke up the cemented gravel so a bucket could handle it, saving blasting. In black and white photographs, blue shows up lighter than it appears in true colors; yellow pho- tographs darker than it appears, and red very dark. Colleges in this country are carrying education {о over a quarter of a million people by their correspondence and extension courses. Rhodium, sister metal of platinum, is being used to plate highway signs, so that the letters will shine at night when headlights flash on them.

Page 121

—aged-in-wood Burley tobacco —extra good taste — for pipe or cigarette 2 full ounces Copyright 1937, n every tin Liecett & MYERS Tosacco Co. When Answering Advertisements Please Mention December Modern Mechanix 121

Page 122

M 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. Diesel Electric Power Generation À new feature essentlal to the complete training of Diesel ex- perts. Completely covers power generation. This extra course is now presented to all Diesel stu- dents wlthout extra tuition, EASY-TO-LEARN MASTER TRAINING National Schools’ training is complete in every respect. It includes all phases of Diesel en- i into the air. gines, fuel injecilon, gasoline, butane, propane and natural gas engines, also Auto-Dlesel 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 dellghiful place to learn—Los Angeles—the play- ground of America, Fascinating surroundings, Your coach rall- road fare will be allowed to Los wee from any point in the Student Servicing Diesel Electric Unit EARN ROOM AND BOARD We help students obtain part- time jobs to earn room and board while learning. This service only for residents of 0. S. Diesel Generating Unit. Diesel Converted Ford Auto NATIONAL FREE \ SCHOOLS W National Schools, Dept, 12-ММА, 1 - 4000 So. Figueroa St, Los Angeles - 1 x NAME; iiie citer ee RE Sons А@Е........ - 1 П | ADDRESS Liedern ТЯ I П duct em UTE STATE enis d lam аа ш иш пз аз аз па пш пы їн ап из иш иш иш па пз пш ы ш шз и ап ан шш анс 122 Filming A Movie War [Continued from page 45] the comedian, as he shaves. A prop man, who was a clever marksman with a sling shot, shat- tered the mirror on the first shot. To create the illusion of shrapnel bursting in | the air, a paper bag is filled with black cardboard chips and flashlight powder and then catapulted A time fuse sets off the powder, explodes the sack and scatters the harmless card- board seraps about so that it looks as if deadly steel shrapnel was pelting the actor-fighters. Explosions for day and night warfare vary. For daylight hostilities bombs are usually made from black powder and bone charcoal so as to send great bunches of black smoke and dust mushrooming skyward. At night white smoke and dust serves the purpose better. Large spot- lights are hidden in shell holes and trenches to enable them to cast a glow on explosions’ smoke. When a building or tree is to be blown up be- fore the camera it is usually weakened first or constructed in such way as to crack-up from a small charge of powder. Bricks and masonry are often made from papier-mache if players are to be in the danger zone when the building blows up. Every explosive expert has his own tricks for making movie wars. There are about a dozen employed at this odd occupation in Hollywood. Each has a different system for laying out a war. Some use one control board to manage their explosives, while others have several assistants posted at different spots over the battlefield to handle various explosions. They are always to one side, out of the camera’s range. Cameras with telephoto lens are often used to film danger- ous mine explosions from a distance. James Whale, the director of The Road Back, was in touch with the actor-soldiers on the movie battlefield at all times by means of an elaborate loud speaker system. Megaphones, that directors once shouted through in the old days, have been replaced by the more audible electrically operated loud speaker systems. Many of the more thrilling over the top attacks were taken without sound being recorded. The little sound mike would have had a busy time keeping up with the player-soldiers. And the sounds would not be as real as those created by the sound men and later “dubbed-in” the film. It might be well to mention the number of persons besides the actual actors and extras who helped to make the cinema war. One hundred and twenty-four property men, wardrobe men, wardrobe checkers, gunsmiths and assistant “powder monkeys” were required to keep track of the equipment used. A special prop and ward- robe room was constructed near the set, from which the cleaned uniforms, rifles, and the day’s supply of ammunition were issued to the fighters. Eighty-seven electricians were needed to operate several hundred big lamps required to illuminate the battlefield for night shooting. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 123

-o AMAZING | _ &DIGHT 11 TUBE | ALL-WAVE SUPERHET | “from а 1 Pube Set to IDAH-Wave Superhet! Sse these — 19 kits in the Radio Builders’ section of the new ALLIED Catalog. Write for Free Paris Lisie for Building any set de- = seribed in this magazine. 12000 аб _ The 1038 ALLIED = Catalog offesale mendous ;selection | of highest | “qualilyradio parts for building c or repairing any circuit. AN standard lines—at lowest prices--available for prompt shipment from our huge .Sleàn stocks, s escapes, Analyzers, Tube-Checkers, Set-Testers, Meters, eic. Latest factory-built _ and Huild-Youx-Owm types. © ALLIED offers instruments for every radio servicing or engi- neering need, : _ WRITE FOR FREE CATALOG TODAY | RADIO CORPORATION AUTOMATIC ELECTRIC TUNING * SELECT-O-MATIC DIAL ALL-WAVE RANGE * AUTOMATIC FREQUENCY CONTROL + 12” DYNAMIC SPEAKER * PRE-SELECTOR STAGE ONE of 61 New KNIGHTS at Amazing Prices! Examine all radio's newest features. Learn the magic of 1938's advancements, Then look for them all in ALLIED's Catalog—in a choice of 61 super-value Radios! For the 1938 Knights bring you radio’s most thrilling features at prices that challenge the industry! In the Knight 11-Tube illustrated, you’ll find Electric Push-Button Tuning—press a button and there's your station instantly. Select-O-Matie 9" Horizontal Dial with all ranges in full view. Giant 12” Eleetro-Dynamie Speaker. Powerful new Superhet circuit tunes everything on the air, three full bands; full 7 Watts Output—Double-tuned LF.’s—R. Е. Preselector—3-gang €ondenser—A. V.C,—Tone Control—all these features and more are yours at the lowest price in radio! See this sensational value now in ALLIED's new Catalog, and 60 other super-value KNIGHTS for every purpose—5 to 16 tubes—for AC, AC-DC, G Volt, 32 Volt, Battery, and Auto operation. Just send coupon. The Catalog of Everything in Radio ALLIED'S new 1938 Catalog is the Complete Supply Guide for Everyone in Radlo. P. А. Systems—new KNIGHT ‘‘Inte~ grated’? Sound Systems from 8 to 60 watts. Amateur Gear— new receivers, transmitters, transcelvers—both factory-built and in kit form; all leading lines. Kits—Parts—Test Instru- ments—Books—Tools—etc. at Radio's lowest prices, Whether you're a Radlo Dealer, Serviceman, P. A. Specialist, or Ama- teur-Experimenter, you need this great book. ALLIED'S cem- Plete stocks and fast service save you tlme. ALLIED'S low prices save you money. Quality equipment that cannot be surpassed—every item is tested and approved by our engineers. Write today for this new catalog. Send coupon nowt Write for FREE PARTS LISTS on any Modern Mechanix kit, Hitch-Hiker's Portable; M. M. Bicycle Set; 1 Tube A-W; Combination Set; Ether Imp, Etc. ALLIED RADIO CORPORATION Dept. 6-M8, 833 W. Jackson Blvd. Chicago, ill, Г] Send your Free 1938 Catalog Г] Send Free Parts List for Address ..... nn m City... State... sees EVERYTHING IN RADIO AT LOWEST PRICES When Answering Advertisements Please Mention December Modern Mechanix 123

Page 124

MAIL COUPON D ig Inain Dock IN "FULL COLORS Page after page shows America's greatest train values, new and ad- vanced features such as the amazingly low priced six wheel drive Hudson steam-type locomotives, the new re- mote control whistle unit, high speed model track, new transformers with circuit breakers included. АП of America’s famous streamline and steam-type trains have been repro- duced. Select your fun-making auto- matic signals, stations, etc. Dads, too, make railroading a hobby. [American Flyer Mfg. Co. SEND FREE ~] | 2252 S. Halsted St., S Chicka, ш. TRAIN BOOK | i Мате... «ооо оооооно ооо онооно онооно оое | | Address ....... l 124 Loads of FUN with the new SOPRANI ACCORDION @ Popularity and romance surround youwithaSoprani, a complete band in itself. Easier play- ing, reduced size and. weight, more beautiful tone, greater volume with a third less d bellowsing. Ampli- phonic feature as- sures rapid prog- ress. Home trial. Easy terms. See your music dealer or send postal for beautiful free book, Writetoday. SOPRANI, INC. Dept. 1234 Ч 030 S. Wabash ‘Ave. Chicago, ШЇ. Build "Polaris" —New Iceboat [Continued from page 15] The runnerplank 15 a solid timber 13 feet long, 12 inches wide and 2 inches thick, preferably of Sitka spruce. Two %-inch holes are drilled through the runnerplank for the bolts, welded to the iron band, which locks the backbone to the plank. Disregard old-fashioned wooden hobblers and make them of four pieces of 16-inch long angle- iron that have 3-inch sides. Weld them in pairs 134 inches apart to iron plates measuring 1⁄4 by 134 by 12 inches. The plates are bolted to the ends of the runnerplank. Make the runner chocks of 198 by 315-inch white oak. If you're going to race this craft, align- ment of runner js extremely important for speed. Therefore, to prevent warping, laminate the chocks by cutting the depth of the wood into seven %-їпєһ strips, and glue up to size. If you like beauty, alternate the white oak with strips of mahogany for an attractive varnished finish. Make the runner blades by beveling both sides of the stem of the angle iron 45 degrees for soft ice or 60 degrees for hard ice. This can be done in a machine shop for a nominal charge. Through me eross-pieces on both sides of the blades, drill l,-inch holes every 3 inches for fastening to chock with 114-inch Е. Н. screws. The rudder post is welded to a channel, as shown, for the steering runner. An 8-inch grooved wheel is secured to the lower end of post with a set screw. To the top of the tiller post is welded a channel which takes the butt-end of the steer- ing quadrant. Construction of the quadrant neces- sitates steaming to get the bend. The quadrant is hinged to the chanrel, as shown, so that it may be lifted clear for entering and leaving the cockpit. Cross the steering cable to turn the boat the same way as tiller. Before securing hull fittings, sandpaper all surfaces smooth and put on three coats of spar varnish. The insides of the cock- pits may be painted, but all other wooden parts should be varnished. Paint the hobblers and other fittings bronze. The band that secures the backbone to the plank is % by 1% by 28%%-їпсһ iron strap with the ends welded to 12 by 5%-inch bolts whose heads are eut off. Line the band with a leather strap to avoid marring the backbone. A boom traveler is fastened to the deck 4 inches ahead of the tiller post. The main sheet should lead back to a cleat fastened to the cross-piece of the quadrant. To brace the hull, two sides stays of #;-inch cable are fastened to the plank and hull with straps, 1 by 4 inches. Details for the mast-step are Eiven. There is a socket in the mast, which is of 3 by 5 inches by 20-foot spruce, to fit the step. Screw a Marconi metal track to fit slides attached to the sail hoist. The boom is 2 by 4 inches by 9% feet. The mast is stayed up with 34-inch cable stays [Continued on page 153] Accept No Substitutes! Always Insist on the Advertised Brand!

Page 125

BUILD! DID YOU TRAIN FOR A CHARLES ATLAS Holder of title ‘The World's Most Perfectly Developed Man” — who offers you à 7-day TRIAL with results guaranteed. my 1936 Sterling Silver Cup! Read what he says. an ‘Atlas Champion?! Do you want a prize-winning body like this? fed up with having no strength, no vigor, being only HALF- ALIVE? Then listen— Give Me 7 Days and I’Il Prove І Can | Make YOU a Champion! E That's all I ask—SEVEN DAYS! In just ONE WEEK I'll absolutely PROVE. that I can give you, too, the kind of body men respect and women admire! You will actually see and feel the im- provement in even this short time. А I was once a skinny, timid weaklin, of only 97 Ibs. I didn't know what rea health or strength were. I was afraid to fight, ashamed to be seen in a swim- ming suit, А Тһеп I discovered the amazing secret that changed me, like magic, into “The World's Most _ Perfectly Developed Man’’—the title I won twice and have held ever since, against all comers. My secret is Dynamic Tension, It is the tested natural method of developing you inside and out! It not only can give YOU the powerful rippling mus- cles you'd like to see in your own mirror, It also digs down into your system after such needless joy- killing conditions as ordinary constipa- tion, pimples, indigestion, underweight and overweight. When Answering Aduertisements Please Mention December Modern Mechanix BILL, vou SURE HAVE A SWELL | LONG TIME WITH WEIGHTS AND PULLEYS ? Men—meet William J. Goldstein, of Metuchen, N. J., winner of A smashing example of what my Dynamic Tension can do. Look at his sculptured stomach muscles— perfectly proportioned arms—beautiful leg muscles—giant shoulders. "It seems like just yesterday that I mailed you that coupon. Look at me NOW! the only system that can develop a build like mine—right in the privacy of a fellow's own home! No weights. No pulleys. No freak drugs or diets. I’m proud of the way you made me ABsoLuTELY NOT! тне ATLAS wAY -wirH NO APPARATUS- MAKES MUSCLES GROW LIKE MAGIC! Your Dynamic Tension is Are you This is the actoal 1936 — WINNER ОР i "S CHARLES ATLAS ave no use for “con. traptions that can do your MEAREGANARD heart and other vital organs more harm than good. I have no pills or other queer ideas about body.building. My Dynamic Tension method is all it takes to make a NEW MAN of you in double-quick time —and I'm ready to PROVE it to you in a 7-day TRIAL OFFER. 2 Book of Photographs—FREE Let me show you the amazing results CHARLES Droduced for thousands of other menl ATLAS, I'I send you FREE my famous book, Dent. 612 “Everlasting Health and Strength.” 115 East 23rd $ It shows actual photos. It tells 7, exactly what I can now do for I want the proof that your system of your body! Write your name Dynamio Tension will make a New Man: of me—give me a healthy, husky body and big and address carefully on the ø muscle development. Send me your free book, coupon. Mail to me person- “Everlasting Health and Strength." ally today. „ New York, N. Y. : I'll rush your f аша ree сору to you AT "°°" please print or write plainly) ONCE! бап ee ept. ‚1 ast c 23rd Street, New - f лаев, York, ЇЧ. Y.

Page 126

FREE! GENEROUS TEST SAMPLE OF CASCO — AMAZING GLUE = THAT HOLDS PERMANENTLY Good news for every man who gets fun and satisfaction out of building things or doing home repair jobs: the famous CASCO Glue — used for years in the manufacture of fine furniture, pianos, airplanes, boats—is now | available in handy-size packages for home use. CASCO glues everything... permanently: wood to wood or metal, leather, canvas, fibre- board, cardboard, paper. Makes strong water- proofcrack-filler, Swedish putty,tile cement, wall sizing and water-tesistant paint. CASCO is the ideal all-purpose casein glue for homecrafters. Unequalled for joints, veneers and inlays. FREE PROJECT PLANS FOR HOMECRAFTERS Every 25c (or larger) can of CASCO has a cou- pon entitling you to Free Plans for building any one of 24 exclusive proj- ects. Send for Free Illustrative Folder. SEND TODAY FOR FREE SAMPLE (SAVE 2c: Stick this coupon on a penny postcard) Casein Company of America, Inc, 350 Madison Ave., Dept, М. M.-1297, New York, N. Y. C Please send me Free Test Package of CASCO О Please send me Free CASCO Project Folder CASCO sets chemi- cally — like concrete. Heat, moisture, rough usage do not affect it. Name. Address. indi ELECTRIC АРС W£LDER qi Works Off Any Storage Battery 22 or Ordinary Light Sockets.» This New Electric Аге Welder is tnade possible by the invention of a low voltage carbon. Auto А batteries may be used without removing from car. Uses about E same current es four headlight bulbs. Can be usedon110 Volt electric light socket or 32 Volt electric light plant by using a Trindl Con- verter in place of battery. Broken parts are SIMPLY MELTED TOGETHER by the NN 4, white HOT electric arc, in just a few sec- ре iw onds, Produces about 7,000 degrees heat. and milkeans, tanksand brazes broken castings. WORKS onANYTHING ai . Up J foralmost nothing. Used | to 180% profit by factories in many ор” Write TODAY. erations Positive money back guarantee. TRINDL PRODUCTS, 2229-Y M Calumet Ave., Chicago, ill. 126 Stamps From War Torn Spain [Continued from page 70] are really of less interest than the provinces stamps which came before them, some of which, postally used, are going to become rarities indeed. Coats of arms feature most of the charity stamps; figures, portraits, arms, and scenes figure as the designs of the postage stamps. The various province issues were necessary when Franco was conquering, since national or- ganization was not then established. Each section had to have postage of course; and so each section was permitted its own. When Franco had what we might term as a "breathing spell," and set to work to effect a nationalization and a unity of his various conquests, he substituted regular issues for the provincials or provisionals. When these, latter, were in use, postage rates often differed in various localities. When the former, the regular issues, were adopted and introduced, a uniform postage rate was re-established. Collectors who enjoy the serious pursuit of stamps, and find it fun to seek elusive items, should attempt to obtain these provincial stamps, particular on cover. It will not be found a simple task, but the "chase" will add zest to your col- lecting. Decorative Candle Holders [Continued from page 79] Santa Claus cut-outs are very appropriate for the base decorative ornaments of a Christmas candle holder. These jolly looking little fellows are cut from 3-ply paneling, then painted on both sides with the Christmas colors, red and white. Mount the figures on a long wood base, on which is centered a short, lathe-turned upright for the candle stick. The figures are cut out by follow- ing the 14-inch squared pattern. Angels, carol singers and many other characters representative of the Christmas season may be used as decorative units on the Christmas candle base. Cut these figures from 3-ply paneling, paint with bright, glossy enamels and mount to the bases as shown. Lathe-turn the candle stick up- rights and attach all figures to the base with tiny tenons. Candle holders of this type will not only be ap- preciated by the housewife to aid her in arranging an attractive Christmas dinner table, but they offer excellent possibilities for marketing through gift stores, and will return a handsome profit to the maker. Building boards made from sugar cane afford protection against termites in the tropics, accord- ing to recent tests. The giant sequoia trees of the Pacific coast have been called the biggest plants known to man. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 127

NEW 1938 EDITION 250 PICTURES Whether or not you have ever attempted to build а boat you will find unusual interest in the many boat designs described in this latest Modern Mechanix Manual, which contains COMPLETE PLANS FOR BUILDING Outboard Racers—Sailboats—Duckboats—Cruisers Runabouts—Kyacks and Rowboats Also Boat Conditioning Suggestions and Numerous Boat Kinks C AT ALL NEWSSTANDS OR ORDER DIRECT When Answering Advertisements Please Mention December Modern Mechanix 127

Page 128

desire men to learn Elec- U S M f tric Are Welding and get * ы h anui acturers practical experience under actual production conditions in the laboratories of the School of Engineering. Moderate training Fee. Accepted applicants will be fully trained until ready to pass rigid test and assisted in securing employment, presents one of the outstanding op- ortunities for steady income and uture success, Welding is growing rapidly, replacing large and Intricate castings, rivets, nuts, bolts. screws. WwW E L D i N G It is commonly used in assembling ‘anes, hoists, bridges, structural ег; steel work, ete. No limit to the application of welding to indus- try, increasing: durability and reducing manufacturing соры, "There is a declded shortage of properly trained Welding Operators, Technicians and Welding Engineers. Why be content with ordinary work, hit and miss jobs and low pay when in a short t become à trained Specialist in Welding? пе уоп we MI LWA UK Е Ee СНОМ, of 5 OAL О GINEERING MM-1237 Broadway and E. State, Milwaukee, Wis. = = жш = mm - Without obligation send Free Booklet "The Dawn of a Gigantic Industry and [+6 Outstanding Opportunities.” Also tell me how to become a Welding Operator (3 mo.)---- Gas Welder (6 wks.)_..----- Welding Technician (6 mo.).. Welding Engineer (1 yr.).--- Electrical Engineer B. S. Degree (4 yrs.)---- --- Student Loan Plan_--_.----. Refrigeration and Air Condl- tioning Technician (3 mo.).-..- Air Cond. Engr. (1 ут.)-------- Radio, Television (6 mo.).---.. Commercial Radio Engineer (1 yr.) Earn Part Expense Plan......- DO-IT-WITH-SQUABS Easily, steadily raised in only 25 days. Write a postcard for eye-opening free picture book. Why breed for ordinary trade when these great luxury national markets are wide open D в > for all the SQUABS you can ship, every day in the year, at LUXURY prices? We give a large bonus in stock for promptness. _ Rice Farm, 602 How. St., Melrose, Mass. CRAFTSMAN OUTFITS | Get ihese fascinating big sets. Learn skilled craft work. Маке money selling finished products. *HOT SPOT Woodburning Modern electric pen burns designs on wood. leather, cork, etc. ‘Outfit includes wood, paint, patterns. Complete set making Pair of Book- ends, What-Not Rack and 2 Plaques, $2.00. Plywood plaques and non-tarnishable jeweler's metals, with patterns, hammer, tools, full equip- ii ment for "raised metal work.’ Complete set mak- т ng Pair of Bookends and 5 Plaques, $2.00. SOLDIER CASTING Large 3 figure mould, clamps, handles, supply of lead, paints, brushes, electric ladle for making any number of big lead soldlers. Complete $2.00. At your dealers’ or send money order to RAPAPORT BROS. 717 E. OHIO ST., CHICAGO ES NS ME FRE AOPAGE BOOK 128 Designing Your Xmas Cards [Continued from page 105] sled, and also his reindeer, were purchased at a toy store for a dime, while a lump of rock salt furnished the iceberg in the lower left hand corner. This exposure was also made with a small stop, placing the light at a low angle to show the texture of the “snow.” Another card which is less juvenile in appeal than the ones aforementioned, also employs a doll as the principal character in the scene. A | pin cushion doll, from the vanity dresser, 15 seen looking out through a window, made by cutting a hole in a sheet of cardboard, onto a winter's } night scene, the snow being merely flour, with i a toy cardboard church in the distance. In this ; case, all of the light that reached the doll came | through the opening in the cardboard. The cen- tral explanatory illustration shows the camera setup, with camera and light in actual position as ! used. i Any greetings desired may, of course, be writ- i ten onto these cards by either of two methods. | In the cards shown in the accompanying photos, where the lettering appears in white, the greetings were printed on the back of the negatives with a pen and show card ink. While any other ink would have served as well, the show card ink can be washed off, enabling the same negative to be used again for other purposes. Jf preferred, the greet- j ing may be written on the finished card with ink. The simplest of all greetings that can be made by tabletop photography, yet which is remarkably effective, is one in which the greeting is simply written out on white paper and laid on the table top with a candle, pen and ink well with a spray of pine twigs forming the background. This setup is too simple to require much description, except to say the pine boughs were tacked to the wall, and the scene built up on the table underneath. Light from one mazda lamp furnished the illumi- nation with the candle being lighted throughout the exposure. In making up these novel cards, the craftsman will doubtless, be able to think up many other ideas as good or better than those suggested, and | when completed, will have a set of Christmas Ereeting cards which his family will be proud to send out to friends. To replenish the sugar and salt lost by the body when a laborer works in hot surroundings, a | pharmaceutical company is making tablets con- taining seven parts of salt and three parts of dextrose. After seven years of experiments, the Univer- sity of California has devised a way of making a crushed peach product of small clingstone peaches | at reasonable cost, thereby putting these sur- | plus peaches to new use. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 129

The New Industrial Revolution.. Aided by Low Cost Precision Tools Which YOU, Too, Can Own А vital industrial change has occurred in this country during the last ten years, Large production plants, ordi- narily associated with only heavy production equipment, have installed batteries of low-priced motor-driven units —thus achieving greater flexibility, and lower costs. Light manufacturing plants, for greater economy and increased efficiency, are utilizing more and more this new type of motor-driven tool. Building contractors and small shop owners have eagerly adopted low-cost motor-driven units to replace slow, costly hand operations. Át a fraction of the cost of heavy equipment, schools have installed com- plete shops of individual, accurate, convenient machine tool units. Home work-shop owners by the tens of thous- ands have turned to "power tools" to eliminate tedious hand operations — and open new fields to spare-time craftsmanship, NEW 1938 DELTA TOOLS In the vanguard of this industrial revolution, and an im- portant factor in making it possible, are Delta “Quality” Tools. Delta engineers have pioneered numerous basic improvements in motor-driven tools—beginning with the self-contained “unit” idea and including the first really efficient modern scroll saw, the new type low-cost drill press and the radically improved band saws, circular saws, shapers, sanders, grinders, jointers, mortisers, lathes that are the accepted standard of quality the world over. In almost every country in the world—Delta Tools are quietly, efficiently, consistently demonstrating that good tools can be produced at low cost! SEND FOR CATALOG The 1988 Delta Catalog is the guide book to modern motor- driven tools. Send coupon for your copy—and the latest Delta Project Book No. 4—packed full of new and different things to make, with many photographs, working drawings, and com- plete instructions. Enclose 10c for Project Book. Catalog will be mailed postpaid. _ Delta Manufacturing Company 600-634 E. Vienna Ave. Milwaukee, Wisconsin When Answering Advertisements Please Mention December Modern Mechanix THE 17-INCH DRILL PRESSES—the greatest drill press values ever offered. Incorporating numerous exclusive features, including Floating Drive, Pre-loaded Double-Seal Ball Bear- ings, 16-Tooth Splined Spindle, Tilting or Production Table, Safety Spring Wind, Foot Power Feed. Heads for these drill presses can be purchased separately. 14-INCH DELTA DRILL PRESSES, Thoroughly tested by years of the hardest work in industrial shops of all kinds, Delte i4-inch drill presses are still leaders in this field. This year's models are further refined and improved, including the adop- tion throughout of the new internal-zeor clutch inside the spindle "ullev, which automat- cally insures perfect alignment. (Patented). * METAL - CUTTING BAND SAW.It takes the place of а power hacksaw in cutting off bars and shapes; it is used in the tool- room for sawing off tool, die and fixture stock; it will cut uniform strips from sheets; it saves hours of time in cutting templates and similar tools, and will cut almost any material, such as_asbestos, mica, vulcanite, fiber, etc. Four low metal-cutting speeds and one high speed for wood sawing. qum d ne d D M atl ы нынын o n n n m n ны, DELTA MANUFACTURING CO., Dept. M1237 600-634 E. Vienna Ave., Milwaukee, Wis. wood-working tools. City. O Check here if are a Delta user now. 2 CUNG GENE a CES] UE Ec (ШЕЕ ШЕР ES ББА Gen cm НЫШЫ USE О DN TUN caeli QE ваты тышы н [| I enclose 10c (stamps or coin) for which please send | me опе сору of the new 1988 Book No. 4 of “Practical Delta Projects." Also place me on your mailing list # to receive 1938 Delta catalog of quality motor-driven Jf І I [| [| l a 129

Page 130

Where There's Food - | Yowl Find Game! EORR are placing their faith in this basic principle of game restora- tion —" Where there's food, you'll ind game." ANE In one section of Illinois, sportsmen and landowners have planted mote than 400 food patches for game. Simi- lar interest in better hunting | is apparent everywhere! It is part of the WESTERN-WINCHESTER Game Restorae | 5 tion Plan— prepared for YOU by experts. 7 Thousands haveenrolled....Mailthe coupon ' for “UPLAND GAME RESTORATION" and instructions оп HOW to apply the plan to your hunting area, TREE BOOKLET — "UPLAND GAME RESTORATION". WESTERN CARTRIDGE COMPANY, Depe. 105, East Alton, Illinois, Pleasc mail, FREE, your 68-page booklet "UPLAND GAME RESTORATION," a complete textbook of game management. Name сажео cpu sinit aisi eda da дк кыналы ЫЕ DII e ———— Post Осе аав ni onte tb pesi Ѕсасе.......... 1500 NEEDED Concentrate your talents on inventions that will pay BIG MONEY. 1936 Edition of 1500 NEEDED i$ INVENTIONS by R. F. Yates tells what inven- ^ tions manufacturers NEED badly. Describes in detall 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 Ou. Keeps you from working on inventions nobody wants to buy. arge 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 5 days’ examination, return it and get your money back. INVENTORS' SELLING GUIDE How and where to sell patented or unpatented invin- tions. Inventors’ Selling Guide by R. F. Yates, noted authority on inventions, gives classified list of nearly 1000 manufacturers who buy ideas. Tells how to sell unpatented inventlons safely, how to Sell chain stores, how to price inventions, selling by correspondence and demonstration, how to find buy- ers. etc. Tells what an inventor must know about Law, Royalty, Contracts, Patents Pending, Finaneing, yp Schemes, Selling Methods. Cloth bound book, 15 chapters. Also: Take Out C.O.D. Your Own Patents, $1.00 (or 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. 12- M, New York, N. Y. Making Unpat- ented Inventions Pay, 50c 130 Experiments In Chemistry [Continued from page 93} solution of a few crystals of mercuric nitrate is poured on top of the gel. Ina few hours beautiful red bands are formed, and on standing, as many as thirty alternating bands of red and white are formed. The accompanying picture of these rings, made in a U- Tube, was for effective reasons only. A most unusual experiment comes under the name of a “Lead Tree”, This is a flowery spray of many frills and ferns, all made of lead and growing in a gel. The base for this tree is a silicic acid gel. Solu- tion “A” is made up as before. Solution “B” is made up in the following manner: A few crystals of lead acetate or sugar of lead are added to three teaspoons of white vinegar or 5% acetic acid. A thin strip of zinc sheet or foil is placed in a narrow jar. Solution “A” and solution "B" are poured over the strip at the same time. The mixture should completely cover the zinc and should be clear. If solution "B" itself is not clear but milky, more acid or vinegar must be added to it till it is clear and colorless. This gel should set in a few minutes, but may take longer if more acid is used. In an hour or two, growth will be noticed and the next day the jar will be filled with a profuse growth of a "Lead Tree". Probably the most astonishing and intriguing experiment of them all is a type of rhyth-banding called Liesegang's rings. A block of ordinary gelatin dessert is cut open and found to contain beautiful bands of white and red. The base for this experiment is not a silicic acid gel but ordinary unflavored gelatin. One heaping teaspoon of gelatin is dissolved in 34-cup of water which has been heated to boiling in an ordinary saucepan and a few crystals of potassium dichro- mate added. This mixture is poured into a jar with no lip so that the solid gelatin mold can be removed in one piece. When set, the time varying with different grades of gelatin, it is removed from the mold and placed in a solution of V4-teaspoon silver nitrate, or lunar caustic, dissolved in а cup of water. The gelatin and solution are then put in an ice box or refrigerator for two days. Itis then removed from the solution and carefully washed with water. For the most striking effect, the gelatin. should be cut vertically through the center. If this procedure is followed, intricate ring designs can be produced. While these have been but a few of the many thousand interesting experiments that are in- cluded in the important branch of chemistry, which deals with colloids and colloidal solutions, they, nevertheless, show a few of the thrills pro- vided by simple everyday scientific study. Although milk was recently shipped success- fully from Oregon to Manila, on a 26-day journey, the milk drunk in the United States is rarely more than 48 hours old. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 131

Works Off 110 Volt Electric Light Circuit For this unheard of price, you can get the = marvelous Dynamic Super-Charged Welder 27 complete—all ready to plug in your light socket 27 —nothing else like it has ever been made. This new Dynamic Super-Charged Welder is a radi- cal departure from accepted welding practices. It will do the work of welders selling for much higher prices—such as cylinder blocks, bumpers. tanks, etc., and at the same time will solder and braze on the lightest material—and the cost is not $200.00 or $100.00—think of it, the complete price is only $19.75. m SS —m— һи» n These pictures show how easy it is to Operate the Dynamic Super-Charged Welder. А ten year old boy can do a Swell fender repair job—an inexperi- enced man soon can do ali kinds of welding. WELDS CYLINDER BLOCKS, FENDERS, AXLES, BODIES, BUMPERS, FARM MACHINERY, CAST IRON RADIATORS, ETC. With the Dynamie Super-Charged Welder, а man without previous welding experience can male for himself as much as $5.00 on a repair job that can be done in less than one hour. Many welders make as much as $15.00 to $20.00 а day. Despite its serviceability, the Dynamic Welder is light and easily portable—can be carried around by hand and set on the running board of any car you are working on. WORKS ON IRON, STEEL, TIN, BRASS, COPPER AND ALL DYNAMIC SUPER-CHARGED WELDER Does Both Metallic Arc and Carbon Arc Welding. Can be used efficiently on both types of welding. The cost of using the Dynamic Super-Charged Welder Is amazingly low—costs only a few cents an hour to operate. It Is built so strongly that repairs are practically unknown-—you'll never have to worry about them. Jt cools so efficiently that you can use it continuously without ever OTHER METALS. With this welder you can work on all kinds of metal—nothing will stump you—you can tackle anything and in no time at all you will be ablo io do finished repair jobs that will do credit to an expert, Опсе you have the Dynamic outfit, you are all set in a profitable welding business having to stop in the midst of a job to let it cool down. Do you want something casy to sell? You AGENTS WANTED ! can Make big profits introducing to garages, factories, mechanics, janitors und maintenance men the new Dynamic Super- Charged Welder—we'll let you try it for ten days at our risk so you сап be convinced of the immense sales possibilities, Get our big profit plan and ten day trial offer, Just send coupon below and mail it TODAY, DYNAMIC WELDER CO. 2225-AU SILVERTON ROAD, CHICAGO, ILL. i of your own—you boss it yourself. yr "= ш шшш -- В DYNAMIC WELDER co. 2225-AU Silverton Rd., Chicago, Iliinols. | Gentlemen: You may send me full particulars on your big profit B plan and 10 day trial offer. Ы i B Name). nn escosesce nc ecee scarce ness €————À When Answering Advertisements Please Mention December Modern Mechanix 131

Page 132

This MACHINISTS’ Home-Study | Course helps men get 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 o£ Modern Machine Shop Practice 5 volumes—2000 pages—1600 Illustrations (A combined home-study course and reference library) This library of machine shop practice was written for practical men. It 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, etc, etc. Plainly written—completely ilustrated—the best kind of help to the machine-shop man who wants to advance himself. No money down—special price—easy payments EREE EXAMINATION COUPON p McGRAW-HILL BOOK ÇO., Inc., 330 W. 42nd St, NEW YORK, Н. Ү. , nd me for 10 days' free examinatlon the Library of MODERN MACHINE SHOP PRACTICE. If satisfactory I will send $1.50 in 10 days and $3 monthly untll the special price of $16.50 is paid. If not wanted, I will return the books postpaid. р sure prompt shipment write plainly and fill in all lines.) b City and State_ P Position ..---_.- 4 Company Become an EXPERT PHOTOGRAPHER Fascinating hobby or profitable career. Big money- -making opportunities. Grow- ing field. We give you individual training. Commercial, News, Portrait, Advertising or Motion Picture Photography, Personal Attendance and Home Study courses. NEW YORK SN T PHOTOG z YORK INSTITU F RAPHY ТСЕ 10 West 33 St. (Dept. 153) New York City Service your own Radio Sets! —with these ingenious trouble-shooting “Gadgets,” Costs on your Tadios—now you can fix your own—EASILYI handy new devices instantly tell you where to find the trouble in any Save Repair These 2 “sick” radio by the “TROUBLE SYMPTOM” method. They also tell you exactly how to fix it. EASY to service radios this way! Get YOUR pair of 'TROUBLE-SHOOTER' Gadgets today—one for HOME Radio Sets—one for AUTO Radio sets. Keep 'em handy— they'll save you money. PIN A DOLLAR to this ad, write your name and address on it and mail to Dept. MM-127. You don't risk а Penny! Sent postpaid anywhere! 50: RADIO & TECHNICAL PUBLISHING CO. 45 ASTOR PLACE . NEW YORK, N. Y. ORDER EACH Money Back Guarantee! NOW! A Local Heat Applicator [Continued from page 87] from damaging the wire insulation. Smoothing the edges may be sufficient, but a guard like that shown is better. The drink mixer has a removable cap with a number of small holes in the center, and over this a cylindrical lid about 134 inches in diameter. With a chisel, sharp knife or pointed metal shears, cut out the perforated section, and bend the edges inward to provide a smooth opening. Keep the lid, for it is useful as a cover to keep out dust when the lamp is not in use. Bore a hole in the end of the 5-inch length of broom handle, and drive into it a length of threaded rod, leaving about 14-inch projecting. This rod can be a length of 14x20 machine bolt, either brass or iron. Punch a hole in the side of the mixer can, and place a washer on each side of the hole. Insert the handle lug, and fasten it in place with a nut, The handle should be about midway between the bottom and top of the shaker, when the cap is off. Screw the 10-watt lamp bulb into the socket, and the applicator is ready for use. Heat is applied by holding the open end of the cap near or against the object to be heated. At first, you may be dis- appointed with the amount of heat given off by the small bulb; but in a minute or two you will realize that it is adequate—just about all you can pear when the lamp is held against your skin, but not enough to cause a burn. Operating cost is negligible. A suggested improvement for the lamp shown would be the addition of a convenient switch. A small canopy switch mounted in the side of the can, or a feed-through switch in the cord will serve excellently. Although heat application is generally recog- nized as a treatment for various bodily ailments, therapeutic use of a lamp like the one described should be undertaken only upon the advice of a physician. Another precaution is to keep away from bathroom fixtures and other grounded objects when any part of the lamp is in contact with the body. This precaution also holds true for any other electrical device. Blower Keeps Press Clean [Continued from page 91] principle can be applied by using a little ingenuity. The shaping of the main body, the fitting of the funnel and tubing is quite obvious in the details. A point which should be stressed is that the fan shaft must be fitted with a long, well-fitting bush- ing, and provision must be made to oil this through a hole in the shaft. It should be oiled at least every fifteen minutes when in continuous use. When one is working on a job not necessi- tating the blower, the friction wheels are swung out of contact. India was the native home of the castor oil plant. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 133

V5 RE the tales of strange human powers false? Can the mysterious feats per- formed by the mystics of the Orient be ex- plained away as only illusions? Is there an. intangible bond with the universe beyond which draws mankind on? Does a mighty Cosmic intelligence from the reaches of space ebb and flow through the deep recesses of the mind, forming a river of wisdom which can carry men and women to the heights of per- sonal achievement? Have You Had These Experiences ? ..... that unmistakable feeling that you have taken the wrong course of action, that you have violated some inner, unexpressed, better judg- ment. The sudden realization that the silent whisperings of self are cautioning you to keep your own counsel — not to speak words on the tip of your tongue in the presence of another. That something which pushes you forward when you hesitate, or restrains you when you are apt to make а wrong move. "These urges are the subtle influence which when understood and directed has made thou- sands of men and women masters of their lives. "There IS a source of intelligence within you as natural as your senses of sight and hearing, and шет Seen Direct Our Lives? more dependable, which you are NOT using’ now! Challenge this statement! Dare the Rosi- crucians to reveal the functions of this Cosmic mind and its great possibilities to you. Let This Free Book Explain Take this infinite power into your partnership. You can use it in а rational an practical way without interference with your religious beliefs or personal affairs. The Rosicrucians, a world- wide philosophical movement, invite you to use the coupon below, now, today, and obtain a free copy of the fascinating book, "The Secret Heritage,” which explains further. USE THIS COUPON Scribe P. B A. The Rosicruclans, AMORC, Sen Jose. California. 1 am sincerely interested. in knowing more about this unseen, vital power which can be used in acquir- ing the fullness and happiness of life. Please send me, without cost, the book, "Тһе Secret Heritage,” which tells how to receive this information, The ROSICRUCIANS (AMORC) (The Rosicrucians are NOT а religious organization.) When Answering Advertisements Please Mention December Modern Mechanix 133

Page 134

AUDELS Carpenfers | and Builders Guides AY y s 4 vols:56 inside Trade, information for Carpentera, Builders, Join- ers, Building all Woodworkers. Jechanice and 7 These Guides give you the short-cut instructions that you want— including new methods, ideas, solutions, plane, systems ond money saving suggestions. Ар easy progressive course for the apprentice and student. А stira] daily helper and Reference for the master T. arpenters every- where are using these Guides да a Helping Hand to Easier Work, Better Work and Bet- ter Pay. To get this assist- ance for yourself, simply fill in and тай the FREE COU- fnside Trade Information On: PON bel elow. How to use the steel square—How to file and set sows—How to build furniture—How to use а mitre box—How to use the chalk line—How to use rules and scales—IIow to make joints—Carpentera erithmetic—Solving mensuration problems—Es- timating strength of timbors—How to set girders and sills—Hos to frame houses and roofs—How to estimate costs—How to build houses, berns, gaT- ages, bungalows, eto.—How to read and draw plans—Drawing up specifications—How to ex- eavate—How to use settings 12, 13 and 17 on the steel equare—How to build hoists and scaffolds— skylights—Ilow to build stairs—How to put on interior trim—How to hang doors—IIow to lath— lay floors—How to paint : oul THEO. AUDEL & CO., 49 W. 23rd St., New York City Mail Audels Carpenters and Builders Guides, 4 vole. on 7 days’ free trial, If O.K? I will remit $1 in 7 days, and $1 monthly until $6 is paid. Otherwise’ I will return therm- No obligation unless Т am азтізћей, Name................. eeseseehesesssesesssssesosossesososspseses ose Everyone who likes to draw should have this FREE book. Contains money-making tips, cartooning charts, idea creating methods, list of cartoon buyers and other valuable Information. Sont free А with detalls of big prize contest in which you may win $25.00 for drawing а simple cartoon. Also complete particulars on the new Marionette Method of Cartooning. Send no money, Everything offered here is FREE. Rush name at once. CARTOONIST'S EXCHANGE Pleasant Hill, Ohio | Rich, fast-growing field for men thoroughly trained ! in design. manufacture, estimating and install- ing. In 1936, Air Conditioning did a 49 million dcl- lar business—while in the first 5 months of "37 itd skyrocketed to 50 million—14 TIMES as many in- { stallations as in 1933. FREE booklet on home study 4 3 points out YOUR opportunities in Air Conditioning. i 3 Tells WEIY this new industry promises steady work. M good pay, promotion, and jobs where you аге stiil young at 40. No obligation. Write TODAY. 1 AmericanSchool, Dept. AC928, Drexel at58th,Chicago 134 Cause, Cure Of Radio Noises [Continued from page 99] resultant damage to the music or speech. Since most radio receivers do not, as yet, have noise-reducing circuits built in them, no great additional relief is possible except by swear- ing. This always helps. If you really must hear some speech through the explosive local-thunderstorm type of static it sometimes helps if a small “G-10” neon bulb is connected across the speaker transformer in the manner shown on page 99—but don’t expect too much from this. Man-made electrical noises may originate in or near your own home, whereupon they follow the flexible cord which feeds power to the receiver, and thus enter the receiver very directly without even having to reach the antenna. If con- necting the antenna wire of the receiver to its chassis drops the noise considerably but does not stop it, the noise is certain to be entering the set through the power line. Of course every receiver should have a built-in noise filter to keep out interference, but try to buy one which includes such a device. It is, therefore, necessary to add a noise-filter, remembering that those walnut-size gadgets peddled on street corners are fakes. A noise filter of any value is a box-like affair costing around $2 to $4, which is why it was omitted from the receiver. It should be bought on a written under- standing that it may be returned for full price if it does not fit your case, as a filter which works in some places may fail in others. If desired, you can build your own from the ac- companying plans. Before buying anything at all it is best to walk around the house looking for loose lamps, or those nearly ready to burn out, wiggling lamp cords and otherwise hunting for possible noises right at home. "һе next-door home may also be in- vestigated if you are a diplomat. Practically every noise-situation may be helped by using a really good ground. lf no ground is used at all, of course, reception will be noisy, because then the electric light lines are acting as a ground, and that is where noise comes from in the first place. Lf you use a ground, but no antenna, the same story holds, except that the light lines are working as antenna. Do not ground onto waterpipes. Not until the end do we get to the antenna. Electrical noises, even when barred from the ground connection, and from the flexible power-supply cord of the receiver, сап still jump off into space and come in “by radio" through the antenna. If the noises are very bad it is a safe bet they begin within a mile or two from the home, or else enter the set by following an overhead power line. No ordinary citizen can trace this sort of thing down, therefore note for several days, the hours at which the noise is heard, then write the clectric power company and have neighbors do the same. Most public utilities firms want to run this sort of thing down because a noise may be developing into a costly break- down and it is helpful to receive many reports from citizens, preferably every few days until the trouble is found. Seldom indeed does one need to secure aid from newspapers, radio dealers and broadcasting stations in getting action. Power companies do not love to be hated. Certain localities of cities are noisy despite the best present effort of the power and traction companies. Jt is then neces- sary to bar the use of the regular type of antenna. While all sorts of “anti noise antennas" are on the market the best has a simple twisted-pair downlead and a 1-wire top approxi- mately 70 feet long. There is no need for hanging a lot o£ crockery and hardware in the air. The instructions with the antenna are not just chatter, but are vital to the result and should be followed. However the instructions always forget to mention the Proper antenna height for shortwave reception, If the antenna is too high you may hear no Europeans. Numerous fests have proved that sometimes dropping an antenna helps Fores signals, besides cutting down noise. Ina кишп Cistrict а good average seems to be about 30 feet but NO OVER THE HOUSE. For plain reception of American broadcast stations the trick antennas are seldom as good and never better than the old-style single wire, providing the wire is long enough and, except for static. as high as you can make it while staying “in the'clear”, Up to 40 feet and out 60 feet will pick up signals to choke off a lot of noise—if the other 4 noise-gates have Leen closed first. In its winter sleep the lump-nosed bat curls its ears in spiral coils like a ram’s horn. Workers in a famous glass factory in Germany have an orchestra, and play instruments made of Accept No Substitutes! Always Insist on the Advertised Brand!

Page 135

GILBERT ELECTRIC NEW KASTER KIT First and only “slush type" Casting Outfit —makes life-like figures with fifty percent less metal Lift the lever and molten metal flows into the mold. Developed by the Gilbert Hall of Science, Kaster Kit is automatic. Heats electrically. Safest, easiest, fastest casting outfit you can own. Out pops your soldier—''true mold''—correct proportions—not flat and thin like the ordinary kind. Color soldiers to resemble all the armies of the world. See the new No. 7 Kaster Kit at your nearest toy store. Complete with 1 mold, 24 pigs of metal, tools and 2 paints, $6.50. Other Gilbert casting outfits from $1.00. FR E E The Big Kaster Kit Parade—in full colors — shows all 32 Kaster Kit hAolds that make realistic soldiers for you. A twist of the "'metal-saver'^ lever slushes off excess metal— producing a hollow casting. This revolutionary Improvement makes possible fifty ‘percent more figures from the same amountof metal. 32 Different Molds Soldiers, sailors, indians, athletes—these are but ^ a few of the 32 Kaster Kit molds you can get. Set of 4 bandmen, 4 athletes, or 4 military figures, $2.00 per set. [үелерин cues тиан ары ашына The А. C. Gilbert Company 108 Erector Square, New Haven, Conn. + | a a H Please send me your Kaster Kit Parade—free a n a Make Money In Your Workshop — Free Blueprint Booklet More than 125 plans are listed in the new MM Blueprint Booklet for building your own radio, boats, model railway, electric refrigerator, model planes and scores of other projects, Send stamped-addressed envelope for free copy. Modern Mechanix Publishing Co. Fawcett Bldg., Greenwich, Conn. When Answering Advertisements Please Mention December Modern Mechanix 135

Page 136

NEW LOW PRICE Moto-SCO0T 120 MILES PER GAL. 30 MILES PER HOUR "THE WORLD'S GREATEST ECONOMY IN TRANSPORTATION” Here’s the opportunity to buy the original MOTO- от at а new low figure of only $89.00 Е.О.В. j Factory. | Many new features of models now available including | MOTO-CLUTCH & MOTO FLEX, practically no vibra- tion. Greater Horsepower for deliveries апі cross | country running. Deliveries are available immediately from the factory or see your closest dealer, | DEALERS! for details te MOTO SCOOT MFG. CO., Dept. MM12 219 S. Western Ave. There are many valuable terri- tories still open. Write or wire Learn to MOUNT FUN-FASCINATION PROFITS — IN SPARE TIME Эн TAXIDERMY S at пошел EY. MAIL, Save your hunti: trophies, decorate your hom have a grand HOB BY This old reliable School (with 239, бо ‘students) will teach at home to mount BIRDS, MALS, FISH HEADS—and to TAN hides d and aie b wonderful KEAMER- TAN system, also NOVELTY TAXIDERMY, using common specimens—no wild game DET. FREE BOOK 100 beautiful pictures. Tell howY OU can learn Taxidermy easily, quickly, at home. Tells how to EARN FINE PROFITS in spare t time. Rush letter or postal for this strange n marvelous FREE BOOK. Wate NOW—TODA Y. State N. W. School of Taxidermy, 4739 Elwood Bldg., Omaha, Neb. A RAIEWAY TRAFFIC INSPECTOR Make Good with this Speclal Training ) МЕМ-19 to 50—trained as Railway and Bus Passenger o Start, апа advance Write STANDARD "BUSINESS TRAINING INSTITUTE Div. 611 N. Y. Chicago, Ш. Celluloid Tanks Easily Made [Continued from page 107] cut films can be dropped. These should be spaced at least 14-inch apart. At one side attach a small rubber tube and bulb to keep the solution agitated. Squeezing the bulb occasionally during develop- ment will circulate the developer about in the tank, giving more snap to the negatives. Rinse out the bulb each time the tank is used. The roll film tank is made in the same manner. In making the film spool, use dises of celluloid reinforced with narrower strips. Cement -inch strips, spiral fashion, to each disc; these serve as tracks to keep the film turns separated. Holes must be punched in each disc to allow the de- veloper to circulate freely. The axis of the spool is a piece of celluloid formed into a tube around a pencil. Developing tanks are ordinarily used and loaded in the darkroom, and the transparency of the cel- luloid is a considerable aid in judging the density of the negative without removal. In case you wish to load the tank in the darkroom and complete development in white light, however, it can be provided with a lid and all parts made absolutely light tight by merely coating them with black lacquer. This may be applied with a small air brush of the type used for touching up automo- bile fenders. The drawing shows how to construct the lid with a light trap so that developer can be poured in after the tank has been loaded and carried out of the darkroom. Both styles of tanks can be used for fixing the negatives after develop- ment, without removing them. The developer should be well rinsed out before pouring in the fixing solution. Lathe Turned Dinner Gong [Continued from page 71] Melt down the copper first for its flowing temperature of 1980°F, is considerably more than aluminum which is 1300°F, Then add the aluminum. An excellent formula for aluminum bronze is, copper 88% and aluminum 12%. Stir the molten metal with a wood stick and skim off the slag before pouring. Weight down the mould to prevent the upper flask from rising because there is considerably hydraulic action in the process. If the metal in the well is full round and solidly affixed to the bell itself, you may simply leave a 1-inch projection; otherwise machine smooth and drill the dome of ihe bell for a ¥Y%-inch brass or bronze pin which is riveted underneath. Only the outside, and rim of the bell, need be machined and polished; this requiring the reversing of the casting in the chuck. То prevent the chuck jaws from blemishing the rim, after turning, lay a short strip of thick copper under each jaw before tightening. [Continued on page 145] Midget Mike Contest Winner [Continued from page 68] W. Cruger, of Schenectady, New York. Fourth and fifth prizes, consisting of kits for building a freight car, less trucks, were awarded to Wm. G. Gerrish, Brooklyn, N. Y., and Irvin W. Streng, Chicago, Ill., respectively. 136 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 137

"GET ME ТО SOCIAL SECURITY!” 9 Keep your face clean and pre- sentable the whole day —keep supplied with Treet Blades! Their super-keen edges say good riddance to fast-growing beards and skin irritations! Treet Safety Razor Corp., Newark, N. J. CW OF POWER TOOLS M ENGINEERED TO mu Ж xc MM M aep RN eee ak including guard and splitter, steel rip fence and mitre gauge, B à А For the beginner or veteran tool user, an inex- A Driver bench saw will relieve any pensive, precision-built Driver tool makes the ideal home era man 101 НОП of nis ааз gift, Note the features on tools shown here. Proof stock to 214" thick, 14"x10" ground that home craftsmen everywhere are right when cast iron table tilts to 45°, permitting angle cuts, Saw arbor raises and Lowers, Heavy steel ripping fence. Safety guard with splitter which facilitates sawing of green or damp lumber. . they say, “Driver gives a lot of tool for the money!” 0570 DRILL PRESS $19.25 J505 14” As shown, less motor, in- паўд” L540. GAP BED LATHE $18.50 cludes Jacobs Key Chuck, i As shown, including 34” V-belt and box wrench. belt and motor puiley. ere As shown. This low priced tool will handle the bulk of wood Here's a superior drill press inris (82 апа plastic turning and metal turning jobs in the pniaue {лде prlee claas, у machine. home workshop and do them well. It has sturdy Key Chuck. Bronze bear- Motor pulley cast iron gap bed 44 long and 3%” high. Morse ings and ball thrust bearing. and belt Taper centers, bronze bearings, ball thrust bearing Rigid cast iron frame and extra, in head. Capacity: work 3014” long, discs 10” in adjustable 8" table. Spindle i travels 275", Four speeds. Complete in itself for a great variety diameter, А 3 К of creative work, this jig saw is built A 72-page manual is included with each of these machines. Send for the big, to giro hour A ‘ibrationless, — free 1938 catalog describing three full lines of Driver Engineered Bench Saws t iron tubular frame with throat capacity Band Saws, Drill Presses, Jig Saws, Jointers, Lathes, Flexible Shafts an of 14". Table 9"x9" tllts to 43° and Motor Grinders. Walker-Turner Co., Inc., 5127 South Ave., Plainfield, N. J. has accurate quadrant indicator, En- closed drive mechanism lubricated by e splash oil system. Plunger-type blower elears cutting line of sawdust. When Answering Advertisements Please Mention December Modern Mechanix 137

Page 138

JOBS are offering Good Pay... In These Fascinating Fields! Men with foresight are turning attention to the thrilling careers now offered in Radio and Avia- tion-Radio; and to the glamorous future of Television. Trained radio men are in demand—AT GOOD PAY. And now you can get the training needed—practical, with real apparatus to conduct experiments in your own home, followed by four weeks’ intensive training in our big modern labora- tories, (Ours is the only independent school having modern 441-line electronie television equipment.) e Anyone 17 years of age or older with average ability and real ambition can qualify, for Midland makes progress simple by step-by-step experiments and “‘Color-Coded”’ lessons. Gradu- ates are fitted to take exams for two Government Licenses or to step into splendid-paying jobs in 50 to 60 different lines of work, We furnish all equipment and tools, and send you a bus ticket to Kansas City for your postgraduate work. Life- time employment service, Investigate. This may be your future, Send for our big FREE BOOK on RADIO-TELEVISION “I am now a special radio operator with one of the country’s leading air lines, which is the best job I ever had. 1 owe all of this to your training." George Osborne, Kansas City, Mo. "I already had a good job in radio, but since completing your training my salary has doubled." Stanley McKnight, Camden, N. J. “Thanks to your training and help, 1 am getting along fine on my first job in radio." Rollie Terrill, Dallas, Texas. [IDLANDS GREAT ,, EXTENSION TRAINING You get 90 modern, Color-Coded lessons, 10 big shipments of equipment (to own and keep) in- cluding 3-inch Cathode Ray tube, all tools neces- sary, and 10 attractive "Home Laboratory" manuals, Your advance supervised by practical engineers who are connected with the big activ- {ties in Radio, Aviation-Radio and Television. MIDLAND TELEVISION, INC. Fioors 29, 30, 31, Kansas City Power & Light Bldg., Kansas City, Missouri Sponsored by 5000-watt Columbia basic network Station, KM BC. - for thi FREE- боек that will give you all the facts. BINS “MAIL COUPON FOR FREE BOOK № Midland Television, Inc., Kansas City Power & Light Bldg. | 108-М W. 14th St., Kansas City, Mo. (Mail in envelope or paste on posteard) Withoutobligating me, send your FREE BOOK on Radio- І Television opportunities —'"FoRTUNES IN FORESIGHT.” Name, = Age Address В | State, City, -— — LS. Se тае — a s I A UA БЕН 138 Camera Pays You Dividends [Continued from page 113] Many a farm yard has an idea or two going to seed, waiting only for the right chap to come along and photograph them. Ideas found in farm yards and farm homes, which are novel or have a new twist and which come up to specifications, are apt to sell to a mechanical magazine or farm paper. Now these specifications, whether they are to ap- ply to the above fields or for some other type of magazine should, first of all, appeal to the average reader of that magazine. One editor has become quite frank on this topic and says that to interest him, an idea should appeal to 25% of his readers. That, in a way, seems high, but nevertheless your first rule should be to photograph an object, method or idea which will appeal to the average reader of a magazine or paper in a given field. Rule two pertains particularly to the how-to- make type and it is this: Is the article to be photo- graphed easy to make? Rule three is: Will it cost much? The three rules just mentioned cover the field, and if applied before taking the picture, un- necessary expense will thus be avoided. Conversely, there are types of pictures which never sell. This list includes pretty scenery, youngsters at play, staid pictures of residences, buildings, flower gardens, etc. But, let a few good scenery shots illustrate a story on a good fishing trip, with persons close up in at least some of them, and these same pictures, now that they have a purpose, will help put your story over with magazine editors. For example, if you were to photograph a child in a clever homemade con- traption, his presence in the picture will help to sell a print of that contraption. A photo of a home will sell if there is some unusual slant to it. The flower garden shot may bring a check if, around that garden there is an unusual kind of wall, or if the picture, for some other reason, shows some- thing specific. Farm yards yield may salable ideas, and because of the compactness, low cost of operation and adaptability of the small hand camera, you’ll be wise and dollars ahead if you get in the habit of carrying it loaded every time you take a Sunday drive through the country. The writer’s files have more than 3,000 films alone of farm ideas which have sold to many magazines. And to illustrate just how many possibilities a typical farm yard has, let’s walk through one. Stopping the car in the drive you notice an un- usual mail box beside the highway. On the lawn is a clever two-way sprinkler that the mechani- cally minded farm boy has contrived from odds and ends. Back of the house you discover the cellar door equipped with a counterbalance to make opening and closing easier. A simple guard is on one tree to prevent cats from climbing the trunk to get at a bird's nest. Beside the back door is a good but improvised foot scraper, no idea for a garden magazine, but quite in keeping with what a farm paper editor is looking for as a “filler.” [Continued on page 150] Accept No Substitutes!’ Always Insist on the Advertised Brand!

Page 139

new 1937 CATALOG or TRAINS AND ACCESSORIES © Forty-eighi pages of exciting new train combinations — with models of every great new streamliner of the nation pictured in full color. Get a copy of this big book from your nearest toy, hardware, electrical dealer or department store. Or, if you want to be Ihe first in your neighborhood to have a copy, clip the coupon below and mail it o1 once with ten cents in stamps 1o cover the cost of postage and handling. "AT YOUR DEALERS OR MAIL COUPON THE LIONEL CORPORATION, Dept. 92, 15 East 26th Street, New York, N. Y. Enclosed is ten cents in stamps to cover postage ond hondling. Please send а copy of the new 1937 Lionel Catalog. Name Please Print Address, City Stale ANY BOOK IN PRINT! Delivered at your goor, We рау postado, Standard authors, new books, popular editions, fiction, refer- т 4 М $ , ete— fe Plastex Industry needs manufacturers on small scale and for ence, medical, mechanical, children's books big production of X-MAS TREE ORNAMENTS, Art Goods, Novel- all at guaranteed savings, Send card now for ties, Souvenirs, ete.; i "tati n FREES 1938 Catalog. irs, ес.; in Plastex and Marble Imitation. Experience unnecessary. Equipment & simple instructions furnished for Write for our great illustrated book catalog. speed production. Small investment bri 3 i - ngs big returns. Nation- 14е ENS бо pook” lovers. the “answer Poor wide demand in these low priced goods for coming X-mas holidays. К ынс gift problem FREE if you write NOW— Ambitious men have chance for real prosperity. Our'ftee book TODAY! i will interest and benefit you, PLASTEX INDUSTRIES, Dept. 3, CLARKSON PUBLISHING COMPANY 1085 Washington Ave., New York. Dept. P-1253 So. Wabash Ave., CHICAGO, ILLINOIS AIR CONDITIONI ‘IR CONDITI л | YOU MAKE THE PROFIT ELECTRIC REFRIGERATIO WHEN YOU BUILD YOUR OWN TOOLS Lewis castings, plus blueprint engineering service, make every of men to prepare for positions in Air Conditioning and Electric - i -bui 9 і 29 i = Refrigeration. Installation, Service, Maintenance and Sales metal-worker а tool-builder. Choice of 22 wood and metal work positions. No experience needed—we train you under actual working conditions in our own air conditioned Jaboratories. ree employment service. Get free book —STEP UP TO SUCCESS—just off the press. Write NOW to “эмм. MILWAUKEE Ea 34-Year-0ld Organization Now Receiving Applications ing projects, engines, hoist and centrifugal pump. Easy to build, Many available semi-machined. Excellent chance to sell them at a profit. Ideal for school use. Send for free 2-color 32 page catalog illustrating all units and Usting blueprints, When you bulld it yourself, you know it is good. Fa; itary © {сора LEWIS MACHINE TOOL CO. бена. f ENGINEERING З EE 542-5th St., Dept. B San Francisco, Calif. 1237-ММ М. Broadway, Milwaukee, Wis. + 100 PAGES—NO. 10—MAKE BEAUTIFUL FURNITURE at a fractlon of store cost. 14 pages of lumber with prices. Veneers and plywoods of all woods cut in usable sizes without waste. USE THE CRAFTSMAN new process of inlaylng, using our new process ART INLAY GLUE, needing no clamps for the finest work. Hard-to-find rare grains for all woods, Including foreign —special hard-to-find hardware, mouldings, turned legs, etc. Lists and illustrates 76 blueprints of scroll pat- terns, inlay table tops—Kits for inlaid art boxes. plaques, trays, book ends, etc., that anyone can make— 22 pages in color. VENETIAN BLINDS for one-third of usual price. All material requiring only a saw, Order { screw driver, a tack hammer and paint to assemble. CHICAGO CRAFTSMAN WOOD SERVICE CO. 2731 MARY STREET When Answering Advertisements Please Mention December Modern Mechanix 139

Page 140

at Home fo OBS in With this expert drawing озі габр table, drawing board, superior drawing instruments . . . all sent without additional cost, уоп ате all set to learn DRAFTING AT HOME. FREE TRIAL LESSON shows how easy. Mail coupon. THIS DRAWING Р OUTFIT YOURS DRAFTIN Proof of Jobs in Drafting T. M. B., Centralia, Washington, says: “Before receiving my diploma, I had made $1,000.00 in my spare time pre- paring plans. I am finishing a $10.000.00 English resi- dence.” H. J. K., Rockford, Illinois, writes: “This year I have done $425,000.00 worth of work, and this year looks better than last.” F. J. H., Davenport, Iowa, tells us: “I have just been given complete charge of. the drafting room, and have made arrangements to take the Engineers’ examination in the State of Iowa.” Jobs for YOU, too You, like these Chicago Technical College home-study graduates, can prepare for this money-making Бей... where jobs are plentiful . . . advancement quick, All you need do is to send a postal card or the coupon. We will Show you how you can Learn AT HOME in your spare time (or at the College in Chicago) by the fascinating, easy, step-by-step plan originated by this 34- year-old school for Draftsmen, Sample this easy-lesson system of learning Drafting. Send postal card or this coupon. No charge now or later for this FREE LESSON. Prove to yourself how easy it is to learn Drafting by the C. T. C. method in your spare time right in your OWN HOME. CHICAGO TECHNICAL COLLEGE R262 Tech Bldg. 118 E. 26th Street, Chicago, Illinois Please send me FREE Trial Lesson in DRAFTING and show me how I can prepare for good positions in spare time AT HOME. 140 An "O" Gauge Locomotive [Continued from page 83] "Through this, run a small nail or pin for fastening the truck to the floor. With the two inner frames completed, start on the wheels. These are built up in three parts consisting of two cardboard disks and a hollow ring. 'The rings may be either metal or bote. You can purchase a card of twelve (at the sewing or art counter in any ten-cent store) that will serve the purpose very well, Make sure though, that they are exactly 34 inch in diameter, Cut out all of the large disks first to form the wheel flanges and lay them on a flat board. Next glue a ring to each flange and allow them to dry while. cutting out the smaller 34-inch disks. These are glued over the rings to complete the wheels, While the wheels are drying, cut four lengths of lolly-pop dowel for the axles, Trim them evenly, then sandpaper until smooth. Make holes in the wheels just large enough to receive the axles, and push them through. If they fit correctly remove two wheels, one off of each axle, and push them through the holes in the inside frame. Then add the other wheels and glue them securely to the axles. Run the assembly over the track to see that it rolls smoothly. If so, complete the other truck in the same manner, After finishing the inside assembly, begin the four outside frames. Mount them by gluing them to a small balsa block, glued in turn to the inside frame between the wheels. When they have dried re-enforce them with lengths of bamboo, js-inch square, and number 18 copper wire. Consult the plans to make certain that their construction is correct, The chassis, on floor, is made from a piece of pine wood, fr-inch thick 214 inches wide and 9 inches long or cigar wood if there is any handy. Sandpaper it smooth and drill a small hole about 134-inch from each end to take the nail ot pin already placed in the trucks. Fasten the trucks to the chassis by bending the pin over so that the point sticks into the top of the floor. Be sure that it is not fastened too tightly or the trucks will not swing. Next, make a border of cardboard to go around the out- side of the chassis. This border gives the floor the correct thickness, On it the ladders and pilots or cow catchers are mounted, This may be done at this stage if desired. Both pilots and ladders are built up of cardboard strips glued together, as clearly shown in the plans. With the chassis completed, begin work on the body or cab. Make it of stiff cardhoard in four sections; front, back, and two sides. Both front and back as well as the sides are exactly alike. Their construction is very simple. Cut out the windows and doors with a razor blade, using a ruler as a guide. The trimmings inside the windows are made of 14-inch strips of cardboard glued around the frames so that half their width shows. Cellophane is used to represent glass. Cement the front and rear ends of the cab to the floor, making sure that they are both exactly the same distance from the ends of the chassis, or about yy-inch from the edge. The extra platforms go directly in front of the cab ends and are cemented directly to the floor. The body sides are then glued to the floor and ends, and held upright with a few straight pins until the glue sets thoroughly. A cross piece or brace is placed in the inside of the cab of exactly the same width as the inside of the cab. Make this of wood and glue it securely in place. The roof is made of the same grade cardboard as the rest of the cab, and measures about 234-inches wide and 834- inches long, Spread glue all along the top sides of the cab walls and allow the glue to become tacky before attaching the roof. Hold it down with straight pins in the same manner as the sides until it is dry. At this stage all main parts of the locomotive will have been completed. There remains only the details, and these are very easy to make except for the bell, which should be purchased from a model supply house. | : The two searchlights are made by simply cutting off а length of dowel and wrapping writing paper around it so that when paint is applied, the paper will have a smooth metal-like finish. | The platforms for the oil coolers may be made of flat balsa -inch thick, or heavy cardboard. When mounting these glue the center portion only, to the roof. The ends must be left standing up so that the legs, made of small squares of cardboard, can be glued at each corner. . Make the oil coolers of number 18-wire, running the wires through a piece of balsa %4-inch square. They are held above the platform by two cardboard legs glued to both ends of the 14-inch square piece of balsa, measuring %-inch high and 14-inch wide, . Drill twelve holes in the wood, glue the legs in place and mount the assembly on the platforms before you put the copper coolers in place. When you bend the coolers to shape [Continued on page 151] Accept No Substitutes! Always Insist on the Advertised Brand!

Page 141

POLARIZING MICROSCOPES Umm Expose Secrets No Ordinary Microscope Can Reveal You'll be amazed at the startling colors that spring up before your eyes... brilliant, vivid colors that you've never seen before. They've always been there, but it takes a Polarizing Microscope to reveal them. Send today for free hand- Кы somely illustrated folder explain- S ing the wonders of this amazing new invention. MECCANO POLARIZING MICROSCOPES jut tt am пи ра ки ии ONE ии Dt ка ORE TN ш ки ка ип UEM шї ON ON UN иш иш ип ри] M ки SER UN RS їп DR UU NE из ив ии I * The Meccano Company of America, Inc. H $ L Dept. 53,200 Fifth Avenue, New York City a Please send—free—bhandaorely illustrated folder. Voammmmmmmmmm 4 ——— эи шш и ла ж иң ии ка яи ии нї кї ин и пи ии ян яң ли и Би ии GER ищ ин ка ии ки я пи и ри к ии ж ри ш аш MICROMETERS | 2L T3 3 90:2 Ce Tz am Six piece Set, in velvet, ginea leather case, Write for free booklet describing “107 Plans for speclat р leer ошу S1 ui "95. thousandths j Operating a Successful Business of Your Own". to d outside and 3347 inside Св. ир Маке кош I $100 cd теше in врага ments. Guaranteed accurate, easy to read time at home. o peddling or house-to-house selling. ава 29 aet Satisfaction. guaranteed ор Booklet sent free, and without obligation. Weite for your copy today. Ke Rus fe ерогени ы pei eg ELITE PUBLISHING CO. 214 Grand St. New York, N. Y. prepaid on ceipt of remittan: on 0.0, ehipments, send deposit of P So. 00. micro PRODUCTS, 629 Е. Jefferson Avo., Detroit, Mich. { Dept. С New low prices make “this areatable welding service available to everyone. Opens doors to big pay jobs that 7 carry real pront. Н Hobart welders аге базе to Operates AM WELL PLEASED WITH IT AND ‘aster, guaranteed to bring you quality welding business Е . . extra profits will pay for welder without expense IT HAS HELPED ME BUILD My io’ you. Р NO INVESTMENT TERMS-—PROFITS PAY FORIT Extra earnings and savings possible with Hobart Welders make it easy to own without expense. Write for details. HOBART BROS., Box SM-127, TROY, OHIO Send for Your 80 Page Catalo a BALKO ELEC. MOTOR & SUPPLY co., DEPT. 825-105 CLINTON, CHICAGO When Answering Advertisements Please Mention December Modern Mechanix 141

Page 142

The household "utility-man". For craftsmen and manual training. Use for fixing and repair work. In bottles, tubes and cans. iu As R CAMERA Offers hun- B 0 0 K ! dreds of money-sav. ing bargains in Stil and Movie Cameras, Lenses, Films, Enlargers, Exposure Meters, Darkroom Supplles = everything photographic. Choose from America’s /7 most complete varled stock—from world's leading makers: Eastman, Zeiss, Bell & Howell, Graflex, Korona, Bausch & Lomb, etc. 10 Days ‘Trial—Satisfactlon Guaran- (Xour camera, equipment taken іп Write for Free Camera Catalog Now CENTRAL CAMERA CO. (EST, 1899) 230 S. Wabash, Dept, J-12, Chicago ч ВАТ ТЕВҮГЕ5$. WORLD'S SMALLEST REAL PERFORMING RADIO Amazing Midget radio weighs only З Ozs. com- lete. . Receives stations with clear beautiful ne, Very little static and interference. Noth- USES PATENTED 7] D RECTIFIER—ENTIRELY NEW DESIGN. MECHANICAL patent Wo. 2074887. Not to be confused with cheaply made imitations or UNLAWFUL COPIES. Music and programs come DIRECTLY FROM GRILL OF RADIO! New patented *'Speakophone'' gives more volume and statlons! NOT A TOY. Tunes broadcast band. The newest radio Sensation of the year. Absolutely complete with picture instructions for use in hotels, offices, boats, autos, bed, etc. TAKES FNMNNE SEE C UM A s EE rent or extra wires. A' 24 rN: еро! = od de Gerful service in ALL PARTS OF THE WORLD. THESE ha | ARE FACTS! N Beautiful two color cabinets, slx colors. ing to. adjust or cause trouble—should last for years. FI S. e E SEND ONLY $1.00 and pay postman balance plus postage or send $2.99 (Check, М.О., Cash) and yours will be sent ostpald. GUARANTEED ORDER NOW! TINVTONE RADIO CORP., Dept. M-12, Kearney, Nebr. 142 Simplifying Winter Starting [Continued from page 89] As the ignition system and carburetor are virtually the heart of the automobile’s mechanism, both must be in perfect condition in order that the engine operate satisfactorily. If the foregoing suggestions fail to have any effect on the car’s starting, you may be sure that the trouble is in the ignition circuit. Moisture has a tendency to seep into the distributor housing and short circuit the high tension current. Unless a heavy spark is obtained when the spark plug cable is held three-eighths of an inch from the plug terminal, the ignition system is not performing normally. In this event, the spark coil, distributor or spark plug cables are at fault and each should be individually checked so as to determine the exact seat of the trouble. First of all, remove the distributor cap and wipe off both the inside and outside of the bakelite case with а dry cloth, following this with a second wiping with a cloth slightly moistened with alcohol. The alcohol will absorb all minute particles of moisture that may remain. While the cap is off, continue the overhauling by filing the points and rotary contacts. Where the points are worn to any extent it is advisable to replace them. Worn points exert excess charges on the distributor condenser and may cause it to burn out or short circuit. Expense aud trouble can be saved by prompt replacement of these contacts. Replace the distributor cap, at this point, and repeat the spark test on the plugs. If they show any evidence of re- ceiving weak sparks while the motor is running, replace the old cable with a new one. In cases where the original cablea still provide satisfactory service they may be given additional je by waterproofing with a coat of clear varnish, shellac or acquer. [Continued on page 169] Add Microscope To Camera [Continued from page 96] swung over the toes will then prevent all movement. Among necessary adjuncts is a light-tight adapter to make connection between microscope and camera. For the plain box type of camera, fashion a 4-inch ring of heavy wire and to this sew a sleeve of thick black velvet, nap inward. Drop the ring into the box and pull the velvet through the 3-inch hole in the camera bottom, The other end of the sleeve is then caught around the microscope eyepiece with a heavy rubber band; or even better by a short band of elastic tape fastened with a clothing snap or a hook and eye after one turn around the eyepiece. For other cameras, both ends of the sleeve should be equipped with elastics. Stands for commercial cameras are similar to the one already described except that a vertical slot is cut along the center of the upright and the camera is fastened to a sliding block which runs along this slot, and tightened at any desired elevation by a wing nut. While the whole assembly may be arranged in a horizontal position, such a setup cannot be used with living cultures or anything of a fluid nature. It will therefore be found most convenient to do practically all work in the vertical plane, rigging the cainera up over the microscope, [Continued on page 143] How To Print Your Pictures [Continued from page 109] plain paper back and the sensitized surface can easily be distinguished. Close the frame, put it on the box and turn the light on, for approximately three seconds. This is only a guess; you may spoil two or three sheets for each negative until “timing sense” is acquired. | Remove the paper and dunk it in the developer, holding its edge by means of the wooden tongs. In a few seconds the image will begin to appear. Contact paper should require about 45 or 50 sec- onds for complete development. If it blackens in less time, it has been "overexposed"— the light was kept on too long; if it seems sluggish and doesn't darken enough, it has been "underex- posed." [Continued on page 145] Accept No Substitutes! Always Insist on the Advertised Brand!

Page 143

Add Microscope To Camera [Continued from page 142] Choice of subjects for the initial attempts is very im- portant, since тапу a beginner has been sadly discouraged by his failure to secure good pictures through chance selection of a subject that would challenge the resourcefulness of an expert. Try something simple, flat and of one color, as 2 fly's wing or a stained section of a plant leaf or stem. Pond life mounted in gelatin to prevent movement is also excel- lent. Avoid bulky objects with curved surfaces and ioo great a depth of focus; avoid high power and fine detail; avoid opaque or semiopaque materials that are not perfectly clear by transmitted light. Reserve all such subjects for a later time, when experience has brought knowledge of light- ing, lenses, condensers, filters and other advanced con- siderations. If a strong light source can be obtained from above, throwing a beam of light down upon the slide, it is not difficult to try a low-power shot of some simple object by reflected light. Cut out a %-inch square of a newspaper photograph or make a fingerprint on white paper; pass through xylene for a few minutes and then into thin balsam. When dry, such a slide will make an interesting subject for this type of photomicrograph. At this point the first exposure may be attempted. Clean all glass parts thoroughly, including both surfaces of the slide mount, the mirror, objective and eyepiece of the microscope and the camera lens, if present, Place the slide on the stage and secure a sharp focus, centering the object and getting just the picture which is to be photographed. ‘Then, transfer the microscope to the stand and connect the light-tight adapter so as to exclude all light at this juncture and observe the image on the ground glass. The work may be performed either by day or night. It is not necessary to have a dark room, save for focusing on the ground glass, where a cloth hood may be found useful. Most professionals employ a hand lens in examining the image on the ground glass in order to have the focus as sharp as possible. . If a regulation camera is utilized, set the stop at infinity, open the iris diaphram to its fullest extent and set the shutter at time exposure, shutter open. Affix the camera to the stand so that the lens almost touches the тісоѕсоре eye- piece, put on the light-tight adapter, and open the camera back, focusing on the ground glass. If no such glass is present, as in roll film cameras, one can be easily made or purchased and set into the ledge of the camera back. It must lie in the exact plane of the sensitized film. It is quite essential that the optical axis of this setup, or all parts traversed by light rays, be in accurate alignment. This in- cludes light source, mirror condenser (if present), object, objective, eyepiece, camera lens (if present) and film or plate surface. Be sure that all movable parts are rigidly tightened to prevent vibration. When all is in readiness, remove the ground glass and load the camera. The exposure is best made by snapping the light on and off, the plate being exposed throughout. 'This brings us to а consideration—the most important topic of all—the illumination. Strong sunlight would do, but since it cannot be depended on, or used at night, it has become universal practice to employ a strong artificial light, as that from a small arc or a Mazda lamp, the favorite type being a 6-volt 108-watt Mazda with a filament of tungsten ribhon, though this requires a transformer if hooked up to the house lighting circuit. Regular household bulbs of high wattage may be used just as well by increasing the length of exposure. The lamp should be close to the microscope mirror and for that reason many prefer to attach the light socket permanently to the base of the photomicrographic stand. The length of exposure has to be determined by trial and error because there are so many variable factors. Type of Objective, eyepiece and camera lens (if used), density and color of object, intensity and kind of light, degree of magni- fication, kind of photographic film or plate used, presence ot absence and type of color filter are all considerations affecting the time needed io secure a satisfactory negative. Try making five or six shots, the first with a 34-minute exposure and the rest each 14-minute longer in succession. Keep full and accurate card records of each picture relative to subject, lens combination, kind of light and color filter GE any), type of plate or film and length of exposure. Keep a check on the sequence of these first pictures, then select the best one and use that as a standard in estimating correct length of exposure for other subjects. It is sometimes hard to punch enough light through a microscope. Dense or dark objects, and higher magnifica- tions, require more time. By formulating certain rules of procedure, applying to a particular setup, the resulting pictures will show a steady improvement in quality. The next step involves experiment with light filters. The ideal [Continued on page 164] When Answering Advertisements Please Mention December Modern Mechanix OF THE MEN WHO ANSWER THIS AD WILL RIE SUCCESS! This is no “catch” statement, no idle claim. It is fact— based on the experience of the past ten years. Would you like to be one of the 68%? Fine—then let's get down to brass tacks. LITTLE THINGS MAKE A BIG SUCCESS You have often heard men say—“It’s the breaks that count." It is—but did you ever stop to think how many successful men made their own breaks? For example: Joe was a salesman, no better, no worse than the others, Joe's now a sales manager in the same company. À little thing got Joe that job. His sales reports were clearer, more easily read and better than any other man sent in. "They were fyped. À little thing? Sure/—But it was just that little thing that made Joe stand out from the other good men in the territory. And Joe got the job! "That isn't a rare case. You can multiply Joe's story by hundreds. You probably know of a man yourself who had the same experience. It's happening every day, in every kind of business. For the world wants men who think straight, and write the same way. А FEW PENNIES A DAY FOR A RAISE Like most of us you're probably “ЪгоКе from one pay day to the next." But think of this, mister—A Royal Portable will cost you only a few pennies a day. Just a few pen- nies a day for a raise. A few pennies a day you'll never miss—that you'd spend anyway for something not half as important. Think it over. Апа in the meantime get your- self started on the way up by getting the new book, “Your 14% Better Chance for Success." And let us tell you about the special offer Royal is making on its new Portable to help men like you own one without wreck- ing your budget. Send the coupon. Sore Д FEW PENNIES А DAY buys а OFFER ROYAL PORTABLE “The Typewriter Everyone Can Use” FREE Carrying Case FREE . Touch Typing Course Get this VALUABLE FREE BOOK. It tells what others have been able to do with a Royal Port- able Typewriter—both men and women-—in at- tracting the attention of the boss, in getting ahead and winning promotion, True-life stories. Contains money-making tips and suggestions. YOUR | ИЕ st шиа ОМ THE WAY UPIU EB ш Ш ROYAL TYPEWRITER COMPANY "T п Dept. PF-2, 2 Park Ave., New York, N. Y. m LII should like to know how I can get a Royal Portable for only a FEW PENNIES A DAY, with a ш FREE Carrying Case and FREE Touch ‘Typing Course. E B CII would like a FREE TRIAL of a Royal Portable in ш my home, without any obligation on my part. [| Also send FREE copy of the book, “Your 14% E Better Chance for Success." я Name. шн " Address B = > C

Page 144

У MECHANICAL VV for things mechanical. Study at home in spare time with the International School of Engineer- ing. Thousands of students have geod jobs at big sal- aries. Individual instruction. Quick progress because you are in a class by yourself. Courses written by well- known mechanical engineers. MAIL COUPON FOR FREE BOOKLET А wonderful field for men who have a liking “INTERNATIONAL SCHOOL OF ENGINEERING Associated with the International Correspondence Schools Box 2322-N, Scranton, Penna. Without cost or obligation, please send me full details of your home-study course in MECHANICAL ENGINEERING

NEW Mead Motor Scooter sms ж“ READY!

for e o 1 Cent Pay While You Ride EASY with the TERMS Р.О. В. Money Chicago You Earn! e Here amid last! —a it YET strong enough Tor a poo to gallon, No ou ride with the money you сап 8 DR n Ы Write for available territoriest) er estet Mead CYCLE COMPANY Write us today DEPT.om.2 CHICAGO for free folder \Print YourOwn Cards, Stationery, Advertising, labels, paper, cizeulars, tags, ete, ave money an ше. Бо irect 1 from facto: o aret up | А C 3 8.85, Senior outhts $12 and DN "vi 4 BE LIS | FROM WIND POWER For Lights, Power, Radio. from Auto Generators. New Copyright Book with over 100 Facts about Wind Chargers. Wind-Propellers—Generators—Plants— Batteries, Answers all questions you should know. Including plans for 6 or 32 V. Plant, Send 25е for plans, facts and. catalog, AGENTS WANTED. CURRIER MFG. CO. 407 Terminal, Minneapolis, Minn. ВО simple, so safe a child can run man? Go PY “pete at 30 miles per hour—120 miles Terms—pay a$ y 1 Shipped ready to ride. while E Speclal d PRICE,

Do popular raised printing ilke engraving wlth any of our presses. Print for Others, Big Profits Pays for itself in a short time. Easy rules sent. Write for free

` 144 Two-Tube "Amateur Special" [Continued from page 102] lation, turn the band-setting condenser until a whistle is heard. If the signal is from a phone station, back down the potentiometer to a point where the oscillation ceases. The voice signal then should be heard. For су. (code) reception, keep the potentiometer turned to a point just past oscillation. The receiver's sensitivity in- creases until.its peak is reached just at the point of oscillation. The sensitivity decreases rapidly as the potentiometer is moved either side of this Spot. | The coils should be adusted so that each of the amateur bands comes in with the band setting condenser set at about half capacity. The band- spread condenser then is used to tune over the band. The builder will find that the greatest number of distant stations will come in on the higher frequency bands. The twenty-meter band (14400- 14000 kc.) will give the most consistent DX recep- tion. This band is most active during the daylight hours and just before dark and some- times just after dark in the early evening. Amateur phone stations will be heard on the 160-, 75- and 20-meter bands. The 160-meter band will be found to bring in only the stations within a few hundred miles. The 75-meter phone band will be found a much better DX band, with stations one or two thousand miles coming in frequently. However, for greater distance the listener will find. that the 20-meter band is most satisfactory. Here he will find stations coming in from all parts of the globe. For the builder who is not interested in amateur activity, this receiver will supply plenty of broad- cast station DX. During the first hour that this set was in operation, many European and South American broadcast stations were heard. Several of them were loud enough to be heard throughout the room. Many of the international broadcasts are heard on the 19-, 31- and 49-meter bands. The 49-meter band is the usual one for evening reception, the other two being best for day light listening. However, the listener will learn early in his listening career that the rules do not always’ work. The band on which nothing is heard six nights a week, suddenly may become a splendid night-time band. The would-be “ham” will find that such of the best code practice will be found not always on the amateur bands, but on commercial code fre- quencies. These commercial stations many times transmit at very slow speed and thus are suitable for code students. A single wire about 50 to 100 feet long will be suitable for the antenna. For a ground, use a water pipe, preferably the cold one. Only as last resort connect the ground wire to the gas pipe. This is an unsatisfactory ground in most cases, because of the sealing compound used when [Continued on page 153]

Accept No Substitutes! Always Insist on the Advertised Brand!

Page 145

Lathe Turned Dinner Gong [Continued from page 136] The pin in the bell dome is later slotted on opposite sides, near the top, to take the two forks of the slotted 'end of the strap brass support. If the bell has a clear tone, but you wish to increase its volume, machine more of the metal away from the top portions, reducing the upper thickness to about inch. ж iach base is of maple, turned in the wood lathe to the dimensions indicated in the eee drawings and its top is slightly convexed. Strap brass үу by 56 inch, and of suitable length, is heated red and annealed in water to make (STRAP BRASS. TEM fare sate | CAST ALUMINUM ARLE, den ия" (o V BRONZE NC i } 1429 DIA, In the above details, all dimensions for the Dinner Gong and Hammer are indicated. Make the casting mould on a wood- turning lathe, to dimensions slightly larger than finished bell. more ductile. Tf this isn't done, the brass is apt to break squarely off with slight bending. This is particularly true if the bending or shaping is attempted while red hot. The upper end of the strap is slotted with hack saw and file and drilled for a small pin, the latter locking the bell in position, yet allowing it to rock slightly. Two screws hold the lower end of the strap to the maple base, the strap being bent slightly to conform to the top curve of the base. As a metal faced hammer would dent the bell each time it was struck, turn a maple head and fit brass ferrules cut from brass pipe, over the ends allowing the wood to protrude slightly as shown. Ferrules and wood will blend in a com- mon line. The hammer handle, also a simple lathe operation, is of walnut for contrast and is glued into the head.—Dale R. Van Horn. (Editor's Note: Though no mention was made of the actual casting of the gong, this information will be found in the December, 1936, issue of Modern. Mechanix under the title, “Metal Casting in Aluminum and Bronze", Back issues, containing this article, may be obtained from Modern Me- chanix Pub. Co., Fawcett Bldg., Greenwich, Conn., at 20c.) How To Print Your Pictures [Continued from page 142] When the print looks about right, pull it out, let it drain off a bit, and swish it through the acetic acid for about 10 seconds. This is known as a “short stop” bath, serving to stop the chemical action of the developer. Now let it drain again, and submerge it in the hypo, where it must re- main for at least 15 minutes, Wash the tongs thoroughly in the water jar so as to remove all traces of acetic acid and hypo, and then continue with the next print. Do not get a single drop of liquid on your hands at any time during the printing process. Use the tongs carefully, avoid splashing, and the resulting prints will be clean and spotless. A wet, sloppy darkroom is а sign of a careless worker. [Continued on page 169] When Answering Advertisements Please Mention December Madern Mechanix ' pade "Beautiful finish. 26" DISSTON FINEST А0. © Times change! Homecraftsmen, like mechanics, are buyingthe best saws made. The thriftiest home workshop circular saw is Disston DeLuxe. On any job, it means easier, more accurate cutting. It gives a lifetime's satisfaction. DeLuxe Cross-Cut —Rip— Combination 6" (15"hole),$2.70 8" (V2", 56", 34" hole), $3. 20 7" (%&"Һо1е),$2.10 10" (%°,%"Һо1е) - . . $4.3 DeLuxe Hollow Ground Combination 6, (JA hole) $4.30 Ви (147, Xn Vi hole) $5.40 7" (рое $490. 10" Ga e.e $6.9 APA APA ЛУУУУУУ УЛУ ЛУ ADAP AL PONS PISANI NAP SPA PA Above. D-23 Disston. One of Also. D-8 Disston, Famous, the finest hand saws. Light- world around, as the “Saw ме hr, straight back, narrow Most Carpenters Use.” Wide e. Easy running, fast-cut- blade. Skew back. Same in narrow blade for home work- shop. 26" length ... $3,50 ASK DEALER for DISSTON SAWS = = = m = FREE MANUAL oe os m = | Write us for “Saw, Tool and File Manual” telling How to Choose and Use Saws, FREE, Henry Disston & Sons, Inc., 1208 T acony, Philadelphia, U.S.A. length ......„.›› $3.83

Page 146

DVKES RUTO COURSE With Self Starter. 85 Lessons. 2300 Questions and Answers. Complete Home Training in Book Form. Only %6°% Nothing Else to Buy Leatn auto testing, adjusting, repairing, welding, electrical systems in re time. Big demand and good pay for men who know. Dyke’s Auto cyelopedia, famous for 25 years, prepared in practical lesson form End combined with ‘Self Starter," gives complete tralning at one- fwentieth the cost of other courses. Contains 85 lessons, 2300 ques- tions and answers, 1593 pages, over 4000 Illustrations, permanently bound in two books for convenient use. Weighs over 7 pounds, Guar- anteed to contaln more information than any other course on subiect. Covers every part of all types of cars, Explains principles. Shows practical methods. New cars and late developments Included. А real up to date, streamlined training that brings quick results and makes money. Three sectlons: Elementary—Advanced—Testing, Adjusting, Repair. Study as regular course, using Self Starter as guide. or save time using as reference. Beginners, experienced repair men, car owners, here is your chance to get the finest, most complete and up to date auto training for cnly $6.95. Sent on trial, See coupon below апа Mail Now. Atiaeh ccupon vo letter if you need more space. wr "Шын Ne ees ee ЧЫН ЧЫР А-7 WP CAS ЧЫН m$ ЧЫЫР ЧЫЫР ЧЫН ЧЫР GOODHEART-WILLCOX CO., БЕРҮ, 19, 2009 MICHIGAN AVENUE, CHICAGO Send me Dyke's Auto Training Complete. When delivered I will de- posit $6.95 plus a few cents postage with postman, If not satisfied will return training in 2 days end you will refund my money in full. City -.--.-.---22.2.22.2l22-2.-22-..2.-2-2-22-2-2-2-..----- State ыа Г] Check if $6.05 is sent with coupon, This saves postage cost. Same return and refund privilege. | DIFFERENT N Wrist Gction | ө CORD SET Ш Е Б Monty Maker ШЕ Women ARE GOING WILD ABOUT THIS Glew WRIST ACTION CORD: Here is no ordinary new product. This new Wrist-Action Plug is one of the most re- markable new devices ever offered in the Direct Selling Field! You never saw any- thing like it. Housewives are fascinated— held spellbound by the Instant demonstration оц can give with thls new electric iron cord That swings freely in any direction. Ends kinking and twisting—prevents broken wires, burned fuses. Swivel action plug spins round and round—swings from side io side—keeps cord out of the way—no wonder housewives Бау, “Just what I want," as soon as they lay eyes on it! Sales аге instani— sure! Nothing like it ever before. Here is the self selling big money maker you can clean up with, Get the story at once. Learn hpw you can GET YOUR DEMONSTRATOR WRITE FREE. All territories virgin— wide open. Write immediately NOW! zo sensational money making pla: No-Tro Electric Appliance Corporation 820 W. Erie St. Dept. M-12 Chicago, III. AUTOPOWER Kant-Slam Door Check 15 an amazing new invention that closes all doors sllently and automatically. Closing speed easily ade justed by turning screw at top of check. Holds doors open when wanted open. Operates on new oil principle. Low Priced. Everlasting, Easily installe in ten minutes, Never needs attention. A Real Demonstrator Furnished Every Agent You get orders quickly demonstrating ` actual sample on easy to carry miniature door. Every office, factory, store, Institution and public building needs a Kant-Slam for every door. Rush name and address for detalls of amazing money-making opportunity. KANT-SLAM DOOR CHECK CO. FREE Demonstrator to Workers. Dept. Z-54, Bloomfield. Ind. ZU КЕЗЕ: VN) RCA “RADIO MONEY BACK IF NOT 100% SATISFIED? i for) AUTOMATIC TUNING... Why pay fancy prices for 4 н radios? uy Dom us and pave at 48 CATAL oc FREE up to 50%, One year written | guarantee, No-risk home trial 1938 СА БАГ G 15 tubes, money back if not abso- | for FARMS, HOMES and AUTOS: lutely satisfied. ONE YEAR GUARANTEE B WORLD-WIDE RADIO C0.,2870 Elston Ave., Dept.87, Chicago. Ill. ТГАІГЕВ *BUILDERS ES: 2 * OWNERS AZZZ SEND 25c TODAY (BUYERS Ae | for big, new, 100-page Traller > Builders, Manual and Tells how to build Topa, Cabinete—al eat Electrie Lights, Water Systems, Floor Plans, etc. Pages of valuable ideme and suggestione for Traller Bollders, Buyere Р and Owners. Catalog illuetratee and deacribeg lerg- Г est line of Trailer Parte, Supplies and Equipment [eshte t Beds, in Americal Everything ts here—over 600 iteme— Axles, Brakes, Hitches, Pumps, Stoves, Mattresses Sinks—everything from wheele to, top at lowes prices! Rush 25¢ (coin) today—Satisfaction Positively Guaranteed! 50o Cana 00 Fore!gn 5 i TRAILER SUPPLY CO. Box 438-C Wausau, Wis. CA АТОМ YOUR WAY ro SUCCESS! DON’T COPY - LEARN TO ORIGINATE! RAYE BURNS will teach you HOW to CREATE ORIGINAL CARTOONS at home that you can 85 -— SELL! Course has 26 lessons and 600 illustrations. Send name and address for free details. Only...» RAYE BURNS SCHOOL, Dept. 30, Box 2194, Cleveland, Ohio Learn Public Speaking At home—in spare time. Many overcome *'stage-fright,'' gain gelf-confidence, and increase their_earning power, through вру to away others J by effective speech. Write for tree ooklet, How to 'ork Wonders With Words and requirements. NORTH AMERICAN INSTITUTE, Dept. 2059 3601 Michigan Avenue Chicago, lilinois AUTOPOWER tells you how in plain, easy, simple and illustrated instructions that anyone can follow. Change auto generators into useful, practical A C and D C generators and motors with voltage from 2 to 1,000 volts, for power, light, welding, radio, Generators can be driven by wind, water, fan belt, ete. BUILDING AN À C WELDER THAT ACTUALLY WORKS UP TO A 3/16" ROD. PLANTS. dorsed by thousands. sound, etc. No previous experience nor special tools needed. INSTRUCTIONS TOR ALSO COMPLETE PLANS FOR WIND AND WATER POWER Send for your copy of "AUTOPOWER.'" Only $1.00 postpaid, Already used and en- S. W. DUNCAN, Publisher 146 412 $, Hoyne Ave., Chicago Accept No Substitutes! Always Insist on the Advertised Brand!

Page 147

Are Home Built Planes Safe? [Continued from page 61] considerably simplified, but that it does not ap- pear possible, however, to eliminate stress analysis, or equivalent static tests, if the Bureau is to continue to license the airplane as air- worthy. Naturally, the expense involved in con- ducting engineering tests is a stumbling block for most amateur light plane builders. After all, the primary reason for home-built aircraft is their low production cost. The Bureau of Air Commerce is said to be con- sidering plans whereby this situation can be im- proved, notably the dividing of the engineering cost of a new design among a relatively large number of prospective builders. However, ac- cording to latest reports, nothing has been definitely accomplished in this respect. In the meantime, it is hard to reconcile the hundreds of would-be builders in law-encum- bered states when they know that home-built planes are being flown in more liberal states. MM seeks to consolidate the opinions of its readers on this subject and, through its pages, provide a medium for the exchange of ideas and suggestions that may provide a basis for more liberal air legislation. Here are a few letters received recently. (Send in YOUR opinion). The first letter concerning home-built aircraft was received from George C. Moritz, of New Haven, Conn, who says: Dear Editor: In my opinion the problem of getting a really low- priced plane on the market would have been solved long ago if light plane builders were given a free hand. I feel sure I am not alone in saying that what private aviation needs is more encouragement and less re- strictions for the light plane fan. I would like to see all light plane builders get a "break." Why not have MM sponsor a Light Plane Club of America? George C. Moritz. Reader Moritz's suggestion for a light plane club is undoubtedly prompted by the belief that a united group would have a better chance to secure more liberal air legislation. Perhaps, if enough interest is shown, MM WILL sponsor such a club. Would YOU be interested in joining? ж Ж ж Another light plane fan who favors more free- dom in the matter of air legislation is E. L. Zastrow, of Portage, Wis., whose letter reads: Dear Editor: I most certainly believe that the amateur plane builder should have absolute freedom to do as he pleases, taking for granted, of course, that he does not [Continued on page 152] High School Course ағ Воте | Many Finish in 2 Years Youcancompletethissimplified High School Course as rapidly as your time and abilities permit. Equivalent to resident school work —prepares you for entrance to college. Stand- ard Н. 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- tioninBusinessandIndus- try —for the Professions, College Entrance and so- cial success, No matter what line you may select, elped prepare our special in- High School training will 20 Other Courses Over 150 noted Educators, En- Eipesrs, and Business Men struction material, хс is prove invaluable to you! uset y many resident schoola and colleges, U. S, Navy, and Our moderate fees cover Province of Manitoba, Canada. all instruction, standard We offer, ou quality training textbooks and Diploma. Bt home for the best- paying Easy monthly terms. Get as listed inthe coupon." | ahead in lite. Start your training NOW! Mail coupon for information about line that interests you American School, Drexel at 58th, Chicago American School, Dept. Н-928, Drexel at 58th, Chicago Tell me how to train for success in line checked. No obligation, . DHigh School Course CAccounting & Auditing [Diesel Engineering О Architecture & B’ilding ODrafting & Design OAutomotive Engin’ring OLiberal Arts OBusiness Management OPrivate Secretary OCom'ercial Aeronautics [)Hi'er Ac't'&(C.P.A.) О Electrical Engineering []Highway Engin'r'é DElectricat Кейгїйегас'п [TMechanical Eng'r'& D Air Conditioning О Radio & Television D Civil Engineering О Salesmanship О Complete Law O Steam Engineering Address. «coeptae E ee oe scien Бе When Answering Advertisements Please Mention December Modern Mechanix 147

Page 148

FACTORY TO YOU, NEW REMINGTON NOISELESS PORTABLE 10° А DAY AMOUS Remington Noiseless Portable thet speaks in & whisper, only 10е а day, direct from factory. Standard Keyboard, Auto- matie ribbon reverse. Variable line spacer and ell the conveniences of the finest portable ever built, PLUS the NOISELESS feature. Act now, Send coupon TODAY for details, You don’t RISK a Penny. We send yet а Remington Noiseless Portable for 10 days: free trial. If not satisfied, Bend it back. We pay all ehipping charges. FREE typing course and carrying case. You will recelve FREE DIRE рен simplified hone ED in Touch Typing. Also FREE, в handsome, sturdy carrying case, No obliga- tion, Mail coupon for full details—NO ee ee ee ee ee ee eee ee ee we es on Remington Rend Inc,, Dept. 1m 465 Washington St., Buffalo, М. Tell me, without, obligation, iow to get a new Remington Noiseless Portable, plug Free Typing Course and Carrying Case, for 10c a day. gen d Catalogue. "Written by a Former Member of the Examin- ing Corps (1922-24) of the U. S. Patent Office. Af you want to profit by your idea, you should Ф I | take steps to apply for a U. Patent at ‚опее. Your first step is to get this. Free Book. Т ү ‘interesting illustrated book contains valuable ‘information À С you- should have. Athe [Re Corps of the U. * S. AM com- | $ munications confidential. MAIL COUPON TODAY. for FREE PATENT BOOK and RECORD OF INVENTION Form p Patent Office; REGISTERED PATE NT ATTORNEY “FORMER MEMBER EXAMINING CORPS U. S. PATENT. OFFICE ШЕГУГЕ дрон AE UAE ME ept. D. H your ‘*Record о! eur je Boni iod fo bt iN Patent " and Н 1 r Ч КАМЕ Me —————— ЫН Е ' Е LI а ADDRESS .......elel meh) heh htt 1 a I шшш каш игн а Каши ERN анін аа bust form, groups, landsca; ust hoto SEND NO MONEY Деп шуу "inch entargement sent C. O.D. [AS plas ЕТА Size 8х 10 Inches or smaller if de- sired, Same price for full Jength 0 or @ animale, еїс.; РОГ апјагвешерха 0 of ay part of group picture. Safe return о! original photo guaranteed. 3for$1.00 and within a week г you will receive your enlargement, guaranteed fadeless. Pay postman 47e plus postage —or send 49c with order and we рв; ke advantage of thi Е ЕС СЕА йоз todays Bpectiy size wanted, STANDARD ART STUDIOS, 104 S. Jetterson St., Dep, 1327-W, Chicago 148 Bungalows Of Mud [Continued from page 65] thoroughly modern, artistic and durable houses, using the soil on their own land. Cool in summer, warm in winter, these dwellings retain the charm and graceful aspect of a bygone, courtly age. With the help of three local Mexican laborers, Hindman built his own house. Two concessions were made to modern progress, neither of them being absolutely essential. Plans for the build- ing were drawn by a professional architect and the adobe was laid on a concrete foundation. A photographic record of progress was made by Hindman, and his own photographs are used to illustrate this article. The method of construction, however, remains the same as it was when cas- tanets clacked and guitars strummed in Cali- fornia one hundred years ago. The first step in building ап adobe house is to determine the size and ground plan of your house. Then lay the concrete foundation, if you want one. The advantage of a concrete foundation lies in the fact that it will absorb far less moisture from the surrounding soil than adobe bricks laid di- rectly on the ground. Next, lay out the boun- daries of your basement. Every adobe house has a basement, the dirt excavated being used in building the house! If it is planned to make the room walls of adobe, a narrow, deep basement is indicated, since ground room must be left for their support. If wood or fiber board is to be used for the individual rooms, the basement may comprise almost the full dimen- sions of the building itself. After loosening the top soil of your proposed basement, soak it thoroughly with plenty of water, until it attains the consistency of mud pies made by children. Next, get in there and tramp it with your bare feet! Foolish as it may seem, this is the only practical method of working up the mud into the proper texture. Concrete mixers, tampers, ete, have been tried without success. In this respect, at least, adobe is still making a gallant stand against the encroachments of modern in- genuity. Then, alternate layers of straw and fine gravel, tramping in each layer thoroughly. Shovel out the mixture into wheelbarrows or any other con- tainers. The above process must be repeated with each layer of earth until enough adobe has been obtained. Haul the mixture to any previously selected level spot, spread it out evenly to a depth of four inches, and you are now ready to mold the bricks. One or more molds 12 by 18 by 4 inches in size, and made of wood strips are used. The mixture must be kept constantly wet while the bricks are being molded. Starting at one end of your mud patch, force the mold down into the mixture. When it reaches bottom, separate the resulting brick from the mass and repeat the operation until the whole batch of mud has been made into slabs, 12 by 18 by 4. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 149

Leave a slight space between each brick and its fellows to allow air circulation. Time needed for the bricks to bake depends upon the dryness of the climate and intensity of the sunlight. After the adobe slabs have dried sufficiently to handle, scrape off loose soil and stack them in piles or “ricks.” Adobe walls are laid up in much the same man- ner as a brick wall, except that adobe mortar is used. This is a slightly thinner mud mixture, to which a small amount of sand has been added. Laid flat, their twelve-inch dimension parallel to the wall line, the bricks thus form a wall eighteen inches thick. In the old Spanish type of construction, two bricks were laid end-to-end, achieving a three foot thickness. This has not been found necessary in modern adobe houses. In setting frames for doors and windows, pro- vision should be made for some vertical shrinkage, due to the contraction of the mortar in drying. Interior walls—those of individual rooms—serve as buttresses for the exterior. In the case of a one-room house or one in which the rooms are constructed of wood or fiber board, the same re- sult may be obtained by setting timbers slightly more than head-high, extending the full length and width of the building. In most adobe houses there is no real ceiling, the roof construction taking its place. Satisfac- tory rafters can be made from the poles of any fairly straight native timber, five to seven inches in diameter. These are supported at the ridge by a log of slightly larger diameter, extending through each gable end wall. Each rafter is bolted to a log cross-tie, which in turn is bolted on top of the exterior wall. The roof itself is largely a matter of individual taste—tile, shakes, or a plank foundation with the convenient adobe mixture spread on top. Any of these are in keeping with the Spanish tradition. For flooring, the same size poles used in the rafters make the best support. These are fitted tightly into holes carved on the inside of the exterior walls. When finished, the building may be white- washed and the interior decorated to suit the owner's fancy. If you want a hurry-up job, don't start an adobe house. There's one word which might very well serve as the slogan of adobe builders. That word is "manana"— Spanish for “to-morrow!” The disease called tularemia, which is notably due to handling infected rabbits, may be also transmitted to man by about 20 other kinds of wild life, A patent has been granted for an equal-cut pie pan, which solves the old problem of who gets the biggest piece of pie. AITING íor the nature enthusiast who has yet to know the thrill of microscopy is a hidden world of beauty, mystery, intrigue. Start microscopy this Christmas, and start it with a precision micro» scope — a Bausch & Lomb microscope. MODEL R MICROSCOPE Precision optical parts give the clean, crisp image necessary to a proper study of microscopy. 72 to 300 diameters. In walnut case and with 455-page book “Adventures with the Microscope,” by Prof. J. D. Corring- ton, $21, NEW GEM MICROSCOPE 72 to 150 diameters. In walnut case, with complete instruction manual and course of experiments, $14.50, MICROSCOPE ` ACCESSORIES Gem Science Kit, complete portable microscope laboratory, $9.50. Micro-Projector, $18.50. PROFESSIONAL MICROSCOPES А complete line of world-famous ej | research microscopes, $38. to $774.50. Shown at left, Model Н, $83. Bausch & Lomb laboratory and . Coupon Clipped | EN When Answering Advertisements Please Mention December Modern Mechanix ell 149

Page 150

| Your name on the coupon puts this new Wholesale Radio | Catalog in your hands. 180 pages of “Radio Buys" ... Jultra modern sets, like model EB56. A superhet. with: “extra performance built-in.” Extended tuning range, | teledial tuning (dial your stations just as you dial a phone | number). Volume and tone control give you that “studio sensation.” A real radio “buy.” Model EB56 D 130 DAY FREE TRIAL! 75 1 The most liberal trial plan ever offered. Try a Lafayette СОМРГЕТЕ j in your home. If, after 30 days, you are not entirely WITH TUBES | satisfied, return the set and your money will be refunded. ШШ TO OPERATE Send Jor FREE Xmas Catalog | do all your shopping from these | 40 pages of super bargains. A MAKE THIS AN Nationally advertised electric trains at lowest prices, Electrical home appliances, toys, ete. Just compare prices, Mail coupon or poste on penny post cord, ШЫП. ПП SERVICE Cos. NEWYORK, N.Y. CHICAGO, ILL. ATLANTA, СА | 100 sIXTH AVENUE ТАКТА JACKSON BLVD. 430 W- PEACHTREE ST.; М. W. BOSTON, MASS. BRONX, М.Ү. NEWARK, N. (hee JAMAICA, tt Coupon Clipped 150 | Camera Pays You Dividends [Continued from page 138] At the hog lot there is a chute made from scrap boards which makes it easy to get slop into the trough without climbing the fence. There is also a dandy self-feeder in the yard for young pigs, It is a barrel without any ends, mounted and fast- ened with wire to an old mower wheel. The barn has an unusual type of sliding door and behind there is a small farm shop equipped with a forge made from parts of an old cream separator. These are but a few of the many possible ideas that stand an excellent chance of being accepted by some magazine editor. The urban or suburban dweller need not be handicapped for ideas, either, for they will be found all around him, Look! Down the street a daddy made his young hopeful an ordinary teeter- totter. Then he added hand grips which made the device safer for the youngster, but made it also salable for a fellow who happened along later with a Kodak. The thing that sold a picture of that idea was the addition of the hand grips. The teeter- totter wouldn’t have sold because without the grips there would have been no novelty. A neighbor whose back yard sloped slightly to the rear drive rigged up a very nice spot. He built two small pools, one slightly above the other and some distance apart, and connected them with tiny depressions, lined with cobble stones. Then he fixed the garden hose so it would run water into the first pool. The overflow from this ran down the miniature gulch and filled the second pool. The overflow from this one ran into the drive. Result, a novel touch to an otherwise com- monplace garden. Second result, two pictures that sold. There are hundreds of ideas to be photographed in grocery stores, garages and other places of business. Their logical destination, if they are of primary interest only to other businessmen, is a trade paper in that particular field. One “amateur” photographer with a small hand camera having a moderately fast lens augments his income about 20% by selling shots to news- papers. Most of these go into Sunday editions, although now and then he clicks with a “spot” news shot. Nine out of ten pictures which news- papers use are either obtained from syndicates or staff photographers. Perhaps the percentage is even higher. Nevertheless, the free lance photog- rapher has a good chance to trade the right kind of clear pictures for checks by sending them to the right newspaper editors. The writer has re- ceived as high as $10 for a single print from a New York paper. Syndication is another field which offers many possibilities. А photographer who expects to re- main on good terms with editors never sells a pieture to more than one editor unless the other editors are each in different fields or there is an understanding to that effect. To syndicate a picture you do one of two things. You sell your print ^vith the negative to some Accept No Substitutes! Always Insist on the Advertised Brard?

Page 151

syndicate whose business is the resale of pictures, or you syndicate it yourself. The former method will bring you $3 or $5—occasionally more—or a percentage of the gross profit. The latter method puts all the resulting money in your own pocket. But there will be many rejections, much postage to buy, many envelope flaps to seal, and usually bills to send out. It is not often profitable to syn- dicate anything but outstanding photos or either high spot news value or decided novelty. Cameras earn their keep and show a profit in many ways but the plans just described are per- haps as interesting as any. For one thing, you never know for sure just how much a print will bring; for another, you won't know, until the dust settles, whether you will make a sale. But it's heaps of fun trying, and often surprisingly profit- able. An "O" Gauge Locomotive [Continued from page 140] make sure that they are all the same length and height. Bewteen the two platforms there is another roof or plat- form that is glued directly to the top. It is simply made {тот a piece of cardboard measuring 2 by 434 inches. To this roof attach the mufflers and exhaust stacks. The exhaust stacks are made from a 34-inch cardboard tube cut off 14-inch deep. These in turn are mounted on small platforms made of balsa. The mufflers are -inch dowel, sandpapered smooth and tapered at one end. Use number 18 wire for the lead-in on the roof. The supporting leg is a strip of cardboard 4-inch wide and -inch long, glued in place after the wire has been inserted into the roof. The correct positions for both exhausts and mufflers will be found in the plan. The smaller details, such as the rain troughs above the windows and the straps around the two air tanks, may be made from cardboard strips glued in place or bits of bamboo bent over the end of a hot soldering iron. 'The two air tanks are merely lengths of dowel cut off to the proper size and glued just inside the cardboard border running around the chassis. The pipes that go from the tanks to the floor are made of copper wire, inserted in holes and glued firmly. The seven ladder rungs on either side of the cab and the handles that border each door are wire bent to shape and placed in holes made by a pin. Make sure that the wire is bent evenly and glued securely. Make the couplers out of a bit of balsa wood. Cut then to shape, and paint them black. Glue them in position and you are ready to complete the model. Last of all, paint the locomotive with a good grade of enamel. On the original model a reddish brown, correspond- ing to the actual color of the Southern Pacific gas-oil locomotives, was used. Of course, colors such as red, green or black may be substituted if the herald or insignia of some other railroad is to be affxed to the locomotive, If desired, the builder may cut the scale size heralds from the plans and attach them to the model and thus simplify an otherwise difficult lettering operation, Glacial milk is the opaque-looking water in glacier-fed streams, and is due to the rock dust that the glacier grinds as it moves over its rocky foundations. Next to insects, there are more species of mol- lusks than any other kinds of animal life—about 80,000 mollusk species. A Japanese store is selling a package house, weighing only a ton and a half, which can be as- sembled in three hours: price $170. When Answering Advertisements Please Mention December Modern Mechanix NOW only $1025 buys a 6" Ball-Bearing BLACK & DECKER BENCH GRINDER Look at these features of the new 6-Inch Junior—offered for the first time in a low-priced bench grinder of Black & Decker Quality: 1. Powerful М-Н. P. Motor. 2. Anti- friction ball bearings. 3. Light, strong aluminum housing. 4. Adjustable tool rests, easily removable. 5. Convenient carrying handle. 6. Rubber Feet which hold Grinder firm on bench without bolts. 7. All moving parts carefully bal- anced. The 6-Inch Junior Grinder is just the thing for small tool-sharpening, light grinding, polishing, wire-brushings ttc. A sensational value for .......... only $19.96. BLACK & DECKER 14" JUNIOR DRILL makes quick work of a thousand and one jobs around the shop, garage or home. Ca- ш : pacity, 14-inch holes in steel, -inch holes in wood. Also drives wheels for light grinding, etc. So powerful it cannot be Stalled even when drilling up to rated capacity in steel. А wonderful drill for ...... only $19.95, %-Inch JUNIOR DRILL for larger, heavier work, is an equally great value for ...... only $35.00. MAIL THE COUPON TODAY for complete information and name of nearest dealer where you can see these and other Black & Decker tools. BLACK & DECKER World’s Largest Manufacturer of PORTABLE ELECTRIC TOOLS - MAIL THIS COUPON NOW The Black & Decker Mfg. Co., 712 Pennsylvania Ave., Towson, Md. Please send Free Literature describing the new Black & Decker Junior Tools and address of nearest і B. & D. dealer. Name Occupation.-.-.- —————Á—Á— M — НЫШ Г Address-------- OMEA а | City ннан Б5#айөв.------------- | ———— — ьа Cm ees ce ee ee ee et 151

Page 152

CORONA 1938 SPEED MODEL We've made around two million Corona Portables— but these new 1938 machines are the finest yet! Amazingly complete, professionally fast and easy to operate, and made to last for years. Dollar for dollar they give you unmatched value, Ask any dealer to show you their many exclusive features— the effort- less “Floating Shift," the Touch Selector, Piano Key Action, All-around Frame, etc., etc. And then ask about the new easy-payment plan—as.low as $1.00 а week! Lets you pay for it as you use it. Free booklet on request; free carrying case with each Corona, escocceccec MAIL COUPON TODAY esccereres саба а Сота ӨЫ Вугабивв, Ney. I'm thinking of buying а & Corona. Please send free booklet describing models and the ''$1.00 a week” plan. — PLEASE PRINT PLAINLY ===: “(Practical Electricity and House Wiring’? by Н. P. Richter now used by thousands. Adopted officlal text book Indiana Rural Electri- fication; widely praised by electrical engineers, but plainly written and illustrated so you can wire a house to meet all Code require- ments by following slmple instructions. 192 pages with 208 llustrations--but only $1.50. Money back guarantee, FREE catalog also describes new practical books on Radlo, Diesel Engineering, Sheet Metal, Welding, Carpentry, Painting, Decorating. FRED'K J. DRAKE & CO. 181 N. Michigan Ave., Chicago Не Got 1000 w _ ONE OLD COIN B. Max Mehl paid Mr. Brownlee д oj: Georgia $/000.92 for this hat he found Chae ging = DO YOU WANT BIG MONEY for OLD COINS-BILLS- STAMPS | POST YOURSELF! It Pays! Є aid $400.00 to Mra. Dowty of Texas, for one i Dollar; J. D. Martin of Virginia $200.00 g fora ашке Copper Cent, Mr. Menplog, of New York, 52 for one Silver Oh lo, received $140.00 pay highest canh coins, medals, Si la end stampa. "Um. EWILL PAY $100.00 FOR A DIME! 00 for 1918 Th erty Head Nickel hot Buffalo) and hun- ing prices for coins. Send 4с for ге Illustrated cas Folder and МЕНҮ. КҮГЕ ni Da a er рро MR t to you. TEX eto B. MAX ME е! ЕХА: (Largest Rare ‘Coin Company in U. ) bbb) 86 Years. Are Home Built Planes Safe? [Continued from page 147] create a hazard for others. Those who would go to the trouble of constructing a light plane, incurring the expense involved, would be certain to realize that a good job must be turned out. I have learned to fly and have owned two manu- factured planes—a very expensive way of granting a desire to learn aviation. What is more natural than to turn to home-built airplane construction as a means of learning more about my favorite subject, and at the same time, secure a plane at least expense? I fail to see where the home-built airplanes’ record of accidents is out of proportion to the record of other accidents, so why all the “holler” about it? Away with the manacles on amateur aviation! E. L. Zastrow. There is some real “meat” in the letter MM re- ceived from D. B. Thomson, of New York City. He writes: Dear Editor: If the government was more interested in being fair to amateurs than in playing up to light plane manu- facturers, private aviation would increase. Let's band together and see if we can't get some more favorable legislation, The amateur realizes that airplanes must be inspected thoroughly before they can be certified as airworthy. He is willing to submit his home-built plane to such an inspection, but— stress analysis and other engineering tests cost too much money, serving to discourage the amateurs. Why can't the government work up about a half dozen plans of small aircraft that they will know are correctly designed, and sell them to amateurs at a reasonable price? After the amateur builds the plane, according to the government plans, let him submit the plane to a thorough inspection so that all important items such as welding of joints, size of tubing, bracing, etc., can be certified as satisfactory. Government aircraft inspectors could easily deter- mine if suitable materials were used; if welding was done satisfactorily, etc. They do this type of work every day when they inspect commercial airplanes that have been repaired after crack-ups, etc. The above plan, in my estimation, would satisfy both the amateur and the government's requirements, How about it, MM? D. В. Thomson. - It would appear that reader Thomson has sub- mitted the best solution to the problem, to date. Plans drawn up by government aviation experts and sold to amateurs should solve the matter ol proper design. Field inspections by government inspectors should solve the airworthiness prob- lem. What do other MM light plane fans think of this idea? We will be glad to receive photos of home-built airplanes from interested readers of this article. 152 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 153

Two-Tube "Amateur Special" [Continued from page 144] the gas pipes are installed. Usually this material is of high resistance, thereby causing an ineffec- tive ground. A complete list of the parts used in the receiver and the power supply, and the manufacturers' addresses, may be obtained by sending a three- cent stamp to MopEeRN MrcHaNix Publishing Co., 1501 Broadway, New York, N. Y. VALUES OF PARTS SHOWN IN SCHEMATIC DIAGRAM C1—.0001 mf. receiving type mica condenser C2—.000035 mf. variable condenser C3—.0001-mf. variable condenser C4, C5—.0001 тї, receiving type mica condensers C6—2 mf. electrolytic condenser (200 volt) C7—.01 mf. receiving type mica condenser C8—5 mf, electrolytic condenser (35 volt) C9, C12, C13—.003 mf. receiving type mica condensers C10, C11—8 mf, electrolytic condensers (450 volt operating) R1—50,000 ohm potentiometer R2—50,000 ohm resistor (2 watt) R3—1 to 5 megohm resistor (2 watt) R4—.5 megohm resistor (1 watt) R5—2000 ohm resistor (1 watt) R6—40,000 ohm bleeder (50 watt) L1—See table for values 122—500 henry plate choke 13—20 henry filter choke 1,4—20 henry filter choke ВЕСІ, RFC2—2.5 mh. т. f. choke (receiving type) Secondaries giving: L5 (transformer)—420-0-420 volts, 125 milliamperes 5 volts, 3 amperes 6.3 volts, 3 amperes, (center tapped) §1—8-prong socket $2—8-prong socket S$3—4-prong socket $5—4-prong socket Coil forms (four-prong) 174 inches in diameter; four required MISCELLANEOUS PARTS REQUIRED Metal cabniet 7x10x8 inches 6K7, 6C5 tubes (one each) B0 rectifier tube (one) Power supply base board 7x9 inches Subpanel for receiver, 8x7 inches (wood) Spool of 22 or 24 D. C. C. wire for coil winding Push-back wire for wiring receiver and power supply Terminal strips:— one six-terminal one four-terminal one two-terminal One four-inch dial for band spread condenser Two two-inch dials for potentiometer and band setting con- denser One toggle switch (S. P. S. T.) One pilot light mounting with 6.3-volt bulb One small can of liquid coil dope One pair of phones One-inch angle brackets (three required) Miscellaneous bolt, nuts, screws and wire for antenna and ground connections. Antenna insulators, wire, lead-in strip, etc. Build "Polaris" —New Iceboat [Continued from page 124] tightened with turn-buckles. Ready-made cush- ions and backrests may be purchased reasonably for the cockpit. Sharpen the runners as necessary with a file laid flat on the beveled cutting edge, then smooth with an oil stone. Be sure the runners are parallel before tightening hobbler bolts. Align the run- ners fore and aft to prevent drag. Runners should pivot in the hobblers on 14-inch king-bolts, the nuts being locked with cotter pins. When Answering Advertisements Please Mention December Modern Mechanix TO GET A STRONG HOLD OR TIGHTEN LOOSE PARTS ae шы INNER f Smooth-On No. 1 restores full usefulness of household fixtures, utensils and tools that would otherwise have to be discarded. umque Try it for tightening loose Home Auto |4 parts and stopping leaks, use REPAIRS it also on your car for stop- ping leaks in the radiator, hose connections, gas tank, oil and exhaust lines, for patching cracked water jackets, for tightening loose hub caps, mud guards, lamp and tire supports, etc. Smooth-On No. 1 is simple to apply and hardens to everlast- ing tightness. Merely follow directions in the Smooth-On Book which is sent free if you return the coupon. Buy in 7-02., 1-Ib. or 5-lb. can from your nearest hardware store. олаш SMOOTH ON ‚ О ON B Write for FREE BOOK ЅМООТН.ОМ MFG. CO., Dept. 69, 574 Communipaw Ave., Jersey City, N. J. Please send the free Smooth-On Repair Book. 12-37 153

Page 154

SAVES TIME AND LABOR ON ALL CRAFT WORK Everybody who works with his hands— at home, shop, school or profession—can use the efficient, attractive Moto-Tool to advantage. Grinds, drills, carves, pollshes, etc. on all materials, Takes 10 seconds to do minutes hand work. Absolutely sSafe—there are thousands in use, Weighs only 6 oz. operates as easily as handlin: a pencil. Plugs in any light Socket. Amazingly Æ powerful — about 7,000 г. р. m. Chuck handles a large varlety of tools. MODEL 2 59-85 Postpaid REW—MODEL 2 MOTO-TOOL FASTER—MORE POWERFUL Designed for heavier shop work, this practical, rugged machine is recom- mended where precision and accuracy are demanded. The No, 2 Moto-Tool has many refinements—unlt finger grip —chuck lock—snap switch—air cleaner —better cooling—convenient hanger, etc. Weighs 13 oz., develops about 37,000 &, p. m." "Price" 10.80, cu UO Bn aid. SHAPING tool set. for. NIVERSAL TABLE $2.50 either model STAND $4.50stand extra Post- 5575 paid: Ask your dealer for a demonstration or order by Mail on day money back trial. Send for attrac- tive FREE booklet, today. DREMEL MFG. CO. 1024CT, Racine, Wisconsin ONLY 5189 COMPLETE with carbons, resistor compensator, cord, special Funt Educational! Bulld your own welding arc! Weld iron, brass. Melt glass, metal. Make arc light, 1-mile range. Arc furnace. Ultra violet sun-tan rays. Dozens of other interesting experiments, Works from house llght current. (List $4.75.) Yours now for only $1.89. ORDER TODAY! ELECTRICAL SALVAGE CO, Lincoln, Nebr. plug, goggles, Instruction Book, etc. Box 524-E MEAD'S NEW RANGER HAMPIoN/ onreqnestfroa. PER __ BUT FIRST IT'S YOURS Here it is!— $T WEEK TO TRY FOR зо DAYS Сре has evor of- fered during 50 years of leadership—the new super-streamlined Ranger CHAMPIONI Built-in speeaometer, Jump into the saddle—try It а whole month at our risk. Then, If not perfectly satisfied, return at OUR expense! Latest features. Save 1% buying direct from Mead. Send postal for free catalog, Ea: erms and speclal offers! T MEAD CYCLE CO., 1550. Market, Dept. A-279 CHICAGO, U.S.A 154 PARKS AIR COLLEGE -PARKS AIRPORT, “EAST ST.LOUIS; ILL; Offers you college education majoring In aviation Four courses lead to В. R. degrees in Professional Flight, Aviation Operations. Aviation Mechanics, Aeronautical Engineering. 100 acre airport, 14 bulldings, 33 in faculty. 302 enrolled for Fall term. 6,400,000 miles flight training, 1,562 planes. 538 engines repaired and rebuilt in shops. Graduates with all leading aviatlon companies. Dormltorles, dining hall on field. Winter term Jan. 4th. Catalog. Write 11th YEAR MERE REGISTRAR, DEPT. MM- 12 AIR COLLEGE, EAST ST. LOUIS, ILL. Now, ^ booklet—'*Win No obligation. mg ен lothing el eg Page-Davis School of Advertising 3601 Michigan Avenue, Dept, 2059, Chicago, Illinois, U. S. A. New scientlfüe, low-priced hearing aid, the GODSEND,, guaranteed to gire same power io hear аз instruments costing $85 to $175 and HEAR! Save 50 t 80 percent on tha more. E A cost of an electric hearing aid. With a Godsend you hear even whispers CLEANLY and DISTINCTLY. Super-Power Amplifer, and both BONE and AIR Conduction Receivers included at low price. 10 Day TRIAL OFFER. Money-Back Guarantee. Write for FREE DETAILS in plain envelope. GODSEND CO. Dept. C-439, Cineinnatl, Ohio. SPECIAL Correspondence Gourses In RADIO and ELECTRICAL ENGINEERING 95 > ELECTRICAL ENGINEERING S*t, вооа, erago cal field, | Prepare yourself, at Low Cost, for secure future. Modern simplified anyone can understand quickly. course. So ШЫ RADIO ENGINEERING Extra fine course in radio, public address, photo-electric work. Trains you to, be super-service man, real vacuum tube techniclan. Experimental kits furnished Diploma given on completion. Tuition, ONLY 625, either course, eferred payment plan available. Send name quick for free copies of school catalogs student magazines, SEND NOW. LINCOLN ENGINEERING SCHOOL, Lincoln, Nebr. complete detalls. Box 931-51, MAGAZINE Contains Beau- photos of HUMAN FIGURES; Lessons |n Perspective TOONING, Still-life, Chaik-talk, S Etc., For home, school and сог= reSpondence Art Students. Can't be described. То INTRODUCE the finest Art Magazine ever published we offer 5 BIG BACK ISSUES, also a large Cartoon Book, also “‘Ten Talks to Art Students'" also *'Brings the Art Bacon"; ALL for only $1 prepd. (36 mgs, etc. by express $3. Foreign add 50c). Student writes—S100 wouldn't buy ту 64 copies if I couldn'& Interesting! Instructive! Intriguing! None free. You can’t d. у HIS OUT, send with $1 0 ) now to ап, lose. OK or refd. T T! LOCKWOOD ART STUDIO, Dept. 707, Kalamazoo, Міс BUILD YOUR OWN AUTO TRAILER Now you can build your own auto trailer at a fraction of the usual cost. The new “How To Build Trailers? book describes the construction of six cabin trailers, two folding trailers, delivery trailers, boat trailers and hundreds of trailers and camping kinks. Send 50c today for your copy of this big 130 page manual to MODERN MECHANIX PUBL. CO., Greenwich, Conn. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 155

SwNAIR CONDI Cool in Summer— Warm in Winter. Saves 95% of coal bill. Changes and Cleans the air in your home 5 times erery hour. Build for less than $13.00 unit costing $250.00. No better unit ever designed. Send only $3.00 for detailed plans or 10е for information. Money back guarantee. H. W. HERRON, Heating Engineer 134 N. Wyman St. Room 8 Rockford, lil. IN T0 / I Furnish /ЛеЦЇШЇГҮ Steady Work—Big Pay Dally! Run this highly f. profitable business with my money. Operate from your home, office, or spare room—spare or full time. No experlence. Full ine structions furnished. Write for Money-Making de- tails todayl PRUITT CO., 1197 Prultt Bldg., Chicago, 111. event loss of pencils by getting an Abbott Personal Penell Set—pencils with your name imprinted in gold. Six Dixon No. 2 pencils, two No. 3, 1 red and 1 blue marking pencil, and 1 indelible pencll with metal point pro- tector—all for $1, postpald, complete with your пате on every pencil. Beautiful tubular OX. Order a set today for all on your gift list. Money back. guarantee. Shipments made wlthin Ours. ABBOTT PENCIL CO., 644 BEAUBIEN ST., DETROIT, MICH. Learn Profitable Profession in 90 days at Home A Salarlea of Men and Women {п the fascinati ores \ fession of Swedish Massage run as high «24 to : $70 per week but many prefer to open their own of- i Rees. Large Incomes from Doctore, hospitals, seni- tariums and private patients come to those who qualify through our training. Reducing son sheets and booklet—Th a (Successor to National Collega of Massage) alone offers rich rewarda for epecialists. THE College of Owedish Massage E ARTIFICIAL EYES | CIAL e Write for Anatomy Charts, sample les- D oy ror RER. 1601 Warren Bivd., Dept. 958, Chicago ВЕРЕ n А Save Money = Fit Guaranteed We gend a large assortment for you to select from in your own home. Orer 100,000 on hand at all times. All sizes, shapes, coloring, @ zee Finest quality obtainable—at substantlal saving. Satisfactory fit and color guaranteed. Old reliable firm with thousands of regular cus- tomers. Send name of anyone who wenrs an eye for FREE BOOK that tells how we fit eyes for customers all over the world by mail. DENVER OPTIC CO., 1102 University Bldg., Denver, Colo. WANTED — MEN to cast Christmas Goods, 5 and 10c Novelties, Toy Autos, Ashtrays, etc. Can be done in any spare room, basement or garage and no experience necessary, А rare oppor- tunity to devote spare or full time to profitable work. Write Dept. 2. METAL CAST PRODUCTS CO. 1696 Boston Road New York City Furnace CONTRO L Easily Installed; Simple; used with alarm clock. Opens furnace automatically. Insures warm house when you yet up. То build It yourself send 25 cents for drawings and specifications. For complete control with pulleys, chain, hooks for use wlth your clock send one dollar, Postpaid. Your installation will sell all your neighbors at handsonfe profits. RUBRE COMPANY, Shaker Square Station, Shaker Heights, Ohio When Answering Advertisements Please Mention December Modern Mechanix GOVERNMENT START $1260 to $2100 a 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 each pay day.) Their pay is automatically increased yearly to $2,450. Ad- vance may be had to Chief Clerk at $2,700 a year. ($112.50 each pay day.) Railway Postal Clerk, Minneapolis, Minn. “I received my appointment as Railway Postal Clerk and have been working full time and some overtime. Your training taught me what to do and how to do it, To this training must go a large share of the credit." О. K. Domholdt, Minneapolis, Minn. 3 Days On—3 Days Off—Full Pay Railway Postal Clerks on long runs usually work 3 days and have 3 days off duty or in same proportion. During this off duty their pay continues just as though they were working. They travel on a pass when on business. When they grow old, they are retired with a pension. City Mail Carriers, Post Offlce Clerks Clerks and Carriers now get $1,700 the first year on regular and automatically increase $100 a year to $2,100 and $2,300. Working Mati Carrier, Philadelphia, Pa. "As a result of your training I stood 96.8% and was appointed Mall Carrier soon after the examination and am now working. I was also offered a position as Rall- way Postal Clerk.” Kenneth Albert, . Philadelphia, Pa, Customs Inspector Salary $2,100 to start. Men 23 to 45. Work connected with examining baggage and merchandise entering the country from foreign parts covering boats, trains, roads, automobiles, etc. Many Other Positions Many other positions are obtainable, Those wishing these positions should qualify at once. Get Free List of Positions Fill out the following coupon. ‘Tear it off and mail it today—now, at once. . : This investment may result in your getting a big-paid government job. ча на пи ии иш но эз па пи иш эи и ни иш пш eee FRANKLIN INSTITUTE, Dept, 1262, Rochester, М. Y. Rush to me, entirely free of charge (1) a full description of у. 8. Government Jobs; (2) Free сору of illustrated 32-page book, How to Get a Government Job"; with (3) List of U. S. Government Jobs; (4) Tell me what to do to get в U. 8. Government Job. Address cece Г С ы ы T Use This Counon Before You Mislay It. 155

Page 156

GO TO HIGH SCHOOL

IN BEDROOM SLIPPERS! Ir vov feel the need of a high school education — regardless of your age — you can acquire it in the privacy of your own home after your day's work is done. Mail this coupon for information about our modern and widely recognized high school course. Thousands of adults are studying it every night!

INTERNATIONAL CORRESPONDENCE SCHOOLS Box 2323-N., Scranton, Penna. Explain fully about your course in the subject marked X: O HIGH SCHOOL SUBJECTS I3 Automobile Course, Architecture L] Concrete Construction Radio ГЇ Civil Engineering Chemlstry L3 Electrical Engineering Aviation Engines í— ————— Аде..........- "I ————Á——Á

КҮЗ ДА The new Whiz ''2-Speed'' is handiest, 30 DAYS | most practical electric tool ever made, Л] mbines in one tool: (%) Normal СЫЛОО Speed, ideal for Power Jobs, (2) High c Speed perfect for Precision work. Uses 200 different ассеввогіев, instantly in- terchangeable. Handles any material, Metale, Woods, Alloys, Plastics, Glass, Steel, etc, Eney operate. Saves time. Eliminates tedious labor. P. forma Jobs Impossible With Other Tools. Plug Into any socket AC or DC, 110 volts Chuck l4"cnpacity. Ball bearing thrast. Seif enclosed cooling system, Worth Its Welght In Gold" to professional, mechenics and hobby workers, SEND NO MONEY: Pay postman on delivery only $8.95. Try 30 days at our risk, If not 100% satisfied, I. f money returned. ORDER PARAMOUNT PROD. CO. Dept. 12-B, 245 Broadway, New York ANS Èg < wr ep | \ : DISC WHEELS equipped with 107x234" ỌN A (GOODRICH-GOODYEAR-FIRESTONE) XQ. Ze E e Balloon Tires offered at LOWEST PRICES EAS Also complete line of larger tires SS and wheels—Motors, ete, BILD-UR-OWN DEVICES Dept. 127

TODAY FOR PRICES Chicago, Ill. NOW LEARN NAVIGATION with THIS PHENOMENALLY LOW-PRICED SEXTANT. € On land or sea this amazingly accurate instrument makes it easy for you to learn navigation at last. Tested by U. S. Power Squadron instructors. Practical for small craft, aviation students, schools, and home study. Directions free. Complete with vernier to 0.1 degree; non-mag- netic metal; bronze finish. West of Mississippi $4.70, foreign $4.85 post- paid. Returnuble in 5 days if not entirely satisfied. Order today. BOYCE-MEIER EQUIPMENT CO. BOX 281-M BRONXVILLE, М. Y. { 5237 Lake St. THE YEAR'S MOST UNIQUE GIFT $450

SPECIALS—AIR RIFLES & PISTOLS 1 00 20 p € ае Н HAENEL AIR PISTOL = D

ing. game, rats, Н Powerful, easy loading; heavy metal, wood stocks. 7 in. overall; wt. 1 lb. БОО steel BB's FREE, $3.95. No license, powder or pu For target practice, smal etc. Well made, strong,

Heavy Leather Holster—75c. Extra shot, 35c per Keenfire, single shot pistol 200 BB's, Darts Target <a ee жө жа ш eR eee ан $2.00

Crossman Air Riflea, 22 cal. Single—$8.95. Переаѓе! Benjamin Air Rifles, Single shot $5.45. Нереа{ег_ 500 Pellets 177—60с; 22—75c; Darts 177—250; 7 € дол. $2 deposit required on C.0.D's. New bargain catalog. Rifles, Pistols, Binoculars, Telescopes, Knives, etc. Send stamp. LEE SALES Co. (Dept. M) 35 West 32nd St. N. Y. City

ONLY

EARN MONEY Make Color-glazed Concrete Products New, perfected low cost method. No molds, power or costly tools. You build your own equipment from f Plans we furnish. Experience not necessary to make color-glazed concrete garden pottery, statuary casting, giftware—in home or shop—to earn money. MEN—Send 10c TODAY for booklet, colorplate, details of thls money making business. No obli- gation, NATIONAL POTTERIES COMPANY Room 6, 13 W. 26th St. Minneapolis, Minn.

—of Bargains in Militery, Outdoor and Sport Goods, Clothes, Shoes, Boots, Blankets, Tents, Firearms, Boy Scout Sup- Plies, etc. Send 10¢ fot copy to be redeemed on first order, AY EST. 1868

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 whlle learning and prepare yourself for a well paying position or start [п business after completing our course of instruction, Good watch repalrers are In demand and generally, earn very good salaries. For par- Y ticulars apply to the WISCONSIN SCHOOL OF WATCH REPAIRING 524 E. Mason St., Dept. C, Milwaukee, Wis.

WHY NOT RADIO FOR A HOBBY? Have you a hobby? If not why not become a radio experimenter. What a thrill to hear foreign broadcasts on a set built by yourself. Start today by sending 50c for a copy of the big 148-page Radio Builders Manual. Contains plans for building sets of from 1 to 6 tubes. MODERN MECHANIX PUBLISHING CO. GREENWICH, CONN. PRESS CARD For the Free Lance Reporter or Photographer . . 25c An indispensible aid for writing that story, or shooting those pix. GENERAL NEWS Rm. 1637K, Rockefeller Center,

RCA Bldg., New York

156 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 157

What a thrill: when you play your first tune the very first week on в P-A Sax’. Then popularity .,. ad- miring friends, good times, a glori» ous future. Try a new model P-A Sax, Trumpet, Trombone, Clarinet at your local music store, or write for beautifully illustrated book, Finest instruments at amazingly low prices. Easy terms, Write today sure, 1245 | FREE PAN-AMERICAN BAND INST. & CASE CO. BOOK 1230 P-ABullding ELKHART, INDIANA BRONZE FOUNDRY INTERESTING and PROFITABLE Make your own castings of aluminum, copper, bronze, silver, brass. Outfit contains gas furnace with 110 volt, universal motor blower, Inoulding sand, crucibles, tongs, rubber hose, flask, parting materials, and instructlons for use. or making models, trays, dishes, art Objects, tools, shop equipment, etc.; also used for forging, case hardening and heat treating. Price of outfit No. 351, Ө cu. in. crucible capacity, wt. 25 lbs., $13.50. Price of outfit No. 352. 12 cu. in. crucible capacity, wt. 40 Ibs., $10.00. Outfit 353, 24 cu. in. capacity, wt. 65 lbs, $27.50, Check or money order acceptable, express charges C.O.D. KANSAS CITY SPECIALTIES CO. P. O. Box 6022 : Kansas City, Mo. i] NEW vei? “POWERED SCOOTER” $69.50 and v» Goes 5 miles for 16. No gasoline, oll, nolse, or bother to start! Instant actlon—anyone can ride lt—even a 6 year old child the FIRST TRIAL. 100 speeds— perfect control—brakes, lights, horn etc. PLENTY | OF POWERI Hi-speed model goes 35 m.p.h.— | any speed availablel Entirely selfcontained | Power unit and charger. Simply plug into light socket (patented). Unusual range—Heavy duty tires and spring frame give smooth- est ride! ULTRA STREAMLINED—avall- able with airflo parcel carrier. Write for literature on complete line including gas models. EXCLUSIVE DEALERS WANTED. MIDGET MOTORS CORP. Dept. M-12 Splendid opportunities. Prepara 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 4 particulars and requirements. ,.., AMERICAN SCHOOL OF, PHOTOGRAPHY P" 3601 Michigan Avenue Dept. 2059 Chicago, Elinois ON FUEL COSTS. LE Convert your car to burn Diesel oil. Save up to 70% fuel costs, Cheap installation. Wonderful performance. Troven factory method. Different and better. Costs nothing to investigate, Write for free circular No. 5, HAR o 201-204 Manchester ARRINGT: М COMPANY Portland, Oregon “QUICK ACTION" (1937) PERFECTED AUTOMATIC GAS LIGHTER 350% Profit. We pay P.P. Charges $1.00a Dozen. Rush Name and Address for Free Sample . 12 Dozen $8.00 NETPROFIT GREEN 0 WOOD HAN- DLES. Packed on Individual Cards. Write Today. Method Mfg. Co, D Bradford, Pa. Get the FREE Book NS p i орротупіту / а { | 22 a "Y ES 2 SEM = сау ч ps ха е т = Дк fx mM =з м) {М Brimful of terse instructive facts about TELEVISION RADIO SOUND RECORDING ELECTRICITY Note These Interesting Contents Written in plain, understandable language, this free Book gives facts you want to know NATIONAL SCHOOLS із the oldest trade Institu- about the best-paying trades and opportu- tion in the West. Es- nities. 95 illustrations. Major subjects tablished 1905. You include Television ‘Theory and Construction, сап earn room and board while learning. Coach rallroad fare allowed to Los Angeles. This service only for үеден of Pick-up Systems, Amplifiers, Transmitters, Receivers, Cathode Tubes; Radio in all its branches, Receiving, Broadcasting, Trouble- shooting, Construction and Theory; Sound- recording on Discs; Loud Speakers, Talking Picture Projection, Radio Communication, Laws, etc. This book also tells how you ean qualify for these good pay trades by train- ing at NATIONAL SCHOOLS. Send coupon now for free book. NATIONAL SCHOOLS LOS ANGELES NATIONAL SCHOOLS, Dept. 12-MMR 4000 So, Figueroa St., Los Angeles, Calif, Without obligation send your free book. I ornnes ЕЕЕ When Answering Advertisements Please Mention December Modern Mechanix 157

Page 158

In Your Present Stove or Furnace— HOTTER—CHEAPER—No Dirt or Ashes — Twice the Beats any oil burner ever gotten out for low cost, perfect performance. Burns chea) oil & new way, without pre-generating or c o e ging up. Quick intense heat by Simpi Turn of Valve. ^ AGENTS а Try At Our Risk "aleam 30 DAYS' TRIAL Prove" it ends drudgery and dirt of coal or wood; cuts fuel bills in half, pays for itself quickly by what IT SAVES. BIG MONEY F. Silver says, “І can dispose. of 250 HeatKingsbefore FURNACE this year ends.’" CL РЕБЕ SAMPLE |С | Quick HEAT at offered to one energetic man Money. Writenow or woman in each locality Turn of Valve! who wii) Semonstrate and take orders. Write quick, be first to learn how t. take REAL MONEY right now. soare or full time — mail le postcard today UNITED FACTORIES, Р-600 Factory Bidg., Kansas Clty, Mo, RADIO SERVIC Let R. T. A. Train You At Home Write quick f оч mu Free Book that tells you A.’s Practical Home Training | Course Y fers Tipe utmost in RADIO TRAINING including Television, Talking Pictures and Public Address Systems. аске with star- tling facts and Interesting illustrations, Including our sensational Service Equipment omer that helps ju earn money almost at once. dlo progress 5 astounding the world. Heed the E of RADIO! RADIO TRAINING ASS'N. OF AMERICA Dept. MM-127, 4525 Ravenswood Ave., Chicago, lit. MAKE MONEY IN YOUR WORKSHOP Build furniture, auto trailers, canoes, ісероаёв, cruisers, sailboats and electric refrigerators described in REE BLUEPRINT BOOKLET MODERN MECHANIX PUBL. CO., Fawcett Bidg., Greenwich, Conn. RADIO: ELECTRICITY m At Sensafio. alty ООЁ$ Low PRICES , LATEST technical information, by nationally known authorities. New popular, size books. Crystal clear. Tofusely illustrated. Most outstand- ing book values in America! How. To Build Exp. Laby. Work Bench 20¢; Experiments With 110-V Electri- cal Ares 23¢; Motor Transformer Ex- periments 25¢; Radio Manual 30e; Sho) 35e; condensed ‘electrical education. Explains 676 terms, 217 ills,, 48¢; Adjustment & АН ent' of Radio-Electronic Apparatus Equlps you to service your own or others, 654. How To Locate Faults in Radlo—Electronic Appar- atus. Every radio-man and techniclan needs this MAI LED book, Z5) ado Servicing Insuvmente, ТӨ volumes, 5 ireuits, data, opernting In- structions, ete, Hoth for 986; Shore Course n POSTPAID?! Mathematles, Two volumes, "fractions to loga- hms, clear, amazingly complete. Both for $1. 05; Short Course in Electricity and Radio. Two volumes, 332 ills. Newest, most complete. Both for $1.45. Complete Radio-Electrical Library, all 15 Бооке. fine Xmas gift, postpaid, only „ ELECTRONIC PUE. CO., Send cash. check or stamps. Or. books Mailed C.O.D Order NOW or send card for Free Folder de- seribing full line of --$3.98 Low Priced Books! Box 323-C Lincoln, Nebr. 158 о TRAINED PILOTS cnc MECHANICS WANTE for BIG N y JOBS Ø Pay Job in Aviation, Airline Pilots earn up to $700 a month; Mechanies up to $200 a month. Government Approved Flight Training prepares you for any Pilot's License including Transport. Mechanics Tralning prepares you for Mechanic’s License, ERN TRAINING PLANES, 12 laboratories and shops. We assist graduates in Jocating positions, Write now. LINCOLN AIRPLANE & FLYING SCHOOL, 408-G Aircraft Bldg., Lincoln, Nebr. Amazing rubber mold- makine outfit makes perfect flexible molds of plaques, ash trays book-ends. etc. Molds cost from бе to 25е each. Each mold makes hundreds of novelties and glfts to sell up to $1.00 apiece! No experience necessary, Everything fur- Dished. Start profitable business in your home . . . Sell to stores, friends, resorts, road stands or by mail—NOW! Make BIG MONEY full or spare time. Write for complete FREE detalls and easy Inst uc- tions. SO-LO GO-MA MOLD CO., Dept. Z-834, Cincinnati, Ohio. No JOKE To BE DEAF Every deaf person knows that- Mr. Way made himself hear hia watch tick after eing deaf for twenty-five yenra, with his Arti- fieial Ear Drums. He wore them day and night. They stopped his head оївев. They are invisible . andeomfortable no wires or batterles. Write for TRUE STORY. Also ЭШ Denfness. Artificial Ear Drum THE WAY COMPANY 741 McKerchey Bldg. MAKE MONEY Thousands of magazines and newspapers buy MILLIONS of photos from free-lance camera owners every year, We show you what to photo- graph, how to do it. where to sell for biggest profits. Learn at home, in spare time, You may pay for course in small monthly installments. No special camera needed. Write for FREE BOOK. UNIVERSAL PHOTOGRAPHERS, Inc., Studio 3312, 10 West 33rd Street, New York City. Detroit, Michigan WIND ELECTRIC PLANT Build Your Own—We Show You How. Make auto generator light bulldings, play radio, run washing machine and other motors from FREE WIND OWER. No operating costs. Earn money making for others. Dime bring? complete building plans nnd 1938 catalogue listing over 500 windcharger electrical items. The largest and most complete windcharger catalogue ever printed. Over 50 other generator changes Into 6-12-32 and 110 volt plants. Easlly make motors, grinders, drill press, arc welder, Spot welder, electric fence. rebuild batterles, ctc. Satisfaellon guaranteed or dime refunded: .LEJAY MFG. CO. Minneapolis, Minn. uto Mechanics and Welders are in big de- Write fr mand. Complete courses in are and acetylene welding, metal finishins. body and fender bumping, spray paint- ing. Special low rates. Write today. [FREE MICHIGAN TRADE SCHOOL CIRCULAR ich. U 3763 Woodward Ave., Detroit, Mich. 2 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 159

ANIMALS—FISH— TAN HIDES! Here's FUN and PROFIT—you start mounting first day! Fully illustrated, simple, COMPLETE COURSE covers every branch of Taxidermy. Thousands have easily mas- tered Taxidermy. You can, too! Learn modern methods. Ith 89 pict COMPLETE Pract senden 218 subjecis SEND NO MONEY-HURRY 1—72 pay postman, $1 plus few cents postage or send only $1 now and we pay poses MONEY BACK if not 10066 satisfied. You'll be amazed at this amazing bargain. Be quick—send today! Schmidt School of Taxidermy, Dept. 1211, Memphis. Tenn. BEAN’S CANOE SHOE Made of high grade tan elk leather with double oil tanned moccasin sole, rubber heel and Talon Fastener. It is a combination ‘‘Slipper Shoe," used for many purposes around camp, cotlage and home. Colors, brown and black. Tull sizes only, 3 to 12. Widths, D, EE. Men's and ladies'. Write for New Catalog. Mfd. by L. L. BEAN, Inc. Mfrs. Hunting and Camping Specialties 120 Maln St. Freeport, Maine $2.90 Postpaid WILL YOU WEAR THIS SUIT апа Make up to $12 ina Day! Let me send you this fine all-wool tailored suit FREE OF COST. Just follow my easy plan and show the suit to your friends. Make up to $12 in a day easily. No experience—no canvassing necessary. Send for Samples—FREE OF COST Write today for FREE detalls, ACTUAL SAMPLES and *'sure-hire' money getting plans. Send no money. H. J. Collins, Progress Tailoring Co., Dept. Z-137 500 S. Throop St. Chicago, 111. RADIOS..SAVE:50/ сс = "DEAL DIRECT...FACTORY PRICES! Manymodels to se- lectfrom: AC-Dt armchair models; tuning;car radios that operste like city radios! Send postcard for Bargain Catalog FREE. 30. DAY TRIAL plan and agent-user propositionl GOLDENTONE RADIO CO. DEPT.G12, DEARBORN, MICHIGAN FULL SIZE, Sturdily Con- structed Field glasses that wear like spectacles. Enjoy ‘‘front seat view'' all sporting events indoors and outdoors. Powerful lenses—light welght yet strong— Beautifully finished. Separate eye focus and width adjustment. Sent postpaid for $1.98 or C.O.D. plus postage. Money Back Guarantee. HILL-VIOLIN CO., Dept. 251 5248 Drexel Ave. Chicago, ШІ. VISION ADJUSTABLE COFFEE ROUTES PAYING тс $6O National company needs more men at once to make regular calls on local routes. No experience needed. Operate on our capital. Big bonus—S$500.00 cash, or Ford Sedan—besides your weekly earnings, Rush name on postcard for FREE Facts. ALRERT MILLS, 4275 Monmouth, Cincinnati, O. away an opportunity by which his brother tripled his income "T WANT you to know why I am starting to study accounting under your training. I am а married man, with two children, and a wife in poor health. For seven years I have held my job as a shipping clerk for a bakery— without a raise the past six years. “My brother started to work at about the same time I did, and took your training in Higher Accountancy. He has never been out of work, and has progressed steadily until he is now Chief Accountant and Office Manager for an automobile company here, and is making three times as much as I am. “I know I was a sucker for not starting when he did. But 1 was skeptical, and the trainin, cost, even though small, looked like a lot o money with all my doctor bills. 1 know now that the most expensive thing I did was to put off this training, because I can see what it did for my brother."—E. B. k k жож Are you denying yourself a better job, with bigger pay just as Mr. B. did? Have you seen men no smarter than you go up the ladder of success while you stood still? Then—will you do one simple thing to learn how you can train yourself at home for a responsible position, possibly with an income several times as large Gs you are now making? LaSalle Training has been the means by which thousands of men have gotten out of the rut of poor paying jobs and into well paying positions. A few minutes of your time each day, with LaSalle Training in Accountancy, can almost magically fit you to make more than you perhaps ever thought possible. We offer to send you FREE proof. Yes, offer evidence that you can increase—perhaps even double or triple your income. All we ask you to do is mail the coupon below. In return we will send you a 64- page booklet which outlines the „ training; shows how simple and easy it 15 to earn; and the re- wards you can get from this training. ЇЇ you really are sincere, and want to better your position and pay —mail the coupon without a mo- ment's delay. LaSalle Extension University Dept. 12493-HR, Chicago Please send me, free of all cost or obligation, your 64-page, illustrated book, “Accountancy, the Profes- sion That Pays,” telling about the profession of accountancy and your training for success in that field. When Answering Advertisements Please Mention December Modern Mechanix 159

Page 160

Classified Advertisements "Rate for classified ads, 18e per word (include name, address and all numbers), per insertion. -accompany order and be received In this office November Ist for the January issue (on sale November 26th.) Minimum {0 words, Cash must Address Classified Mor., Modern Mechanix Hobbies & Inventions, 1501 Broadway, New York City A. C. GENERATOR PRACTICAL changes for automobile generators. See our advertisement at bottom of page 146. Autopower. ADVERTISING AGENCIES LEARN Advertising quickly at home. Easy practical plan, No text books. Common. school education sufficient. In- teresting booklet and requirements free. Page-Davis School of Advertising, 3601 Michigan Avenue, Dept. 204C, Chicago. 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 100 National Mail Order Publications $4.00: Lists Free. Advertising Bureau, 4515-B Cottage Grove, Chicago. 24 WORDS 40 newspapers $2.00. Goodall Advertising Agency, 742 Market Street, 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-oz. Vanilla 814c. Razor Blades 10 for 814c. 100 Sticks Chew- ing Gum 12c. Christmas Cards, 21 in box, 14c. 150 other bargains, Premiums. Experience Unnecessary. Carnation Co., MN, St. Louis, 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 Mils, 2448 Monmouth, Cincinnati, 10. SELL New and Used Clothing Over 100% profit Selling experience un- necessary. We start you furnishing everything. Catalogue free. Acme Merchandise, AD-1219 So. Jefferson, Chicago. BIG MONEY taking orders; Shirts, Ties, Hosiery, Underwear, Raincoats, Dresses, etc, Sales Kit Free! Ex- perience unnecessary. Write Nimrod, Dept. 132, 4922-28 Lincoln Avenue, Chicago. PROFIT with new products. Make, sell, repeat. Analysis. Research. Guar- anteed formulas. Biggest catalog free. Special prices, leads. Gibson Labora- tory, Chemists, CE-1142 Sunnyside, Chicago. BE YOUR Own Boss! Operate used- new clothing business from store, home, auto. Over 100% profit. Everything furnished. Catalog Free! Roosevelt Mercantile, 550-AD Roosevelt, Chicago, GOLD Reflecting Window Sign Let- ters, Penny Each. Large Sizes. Easily Applied. New Styles. Absolutely Beautiful. Free Samples. Atlas Sign Works, 7941G Halsted, Chicago, Ill. LARGE Profits in your own business. Sell new and used clothing, bankrupt stock. Experience unnecessary. Every- thing furnished. Details free. Publix, 558-EW Roosevelt. Chicago. AMAZING Windshield Defroster, Strange new chemical instantly removes frost, sleet, ice. Desperately needed. Samples sent on trial. Rush name. Kristee 127, Akron, Ohio. 160 1000 BARGAINS, Drygoods, Notions, Drug Sundries, Specialties, Novelties. Agents undersell stores. Free catalog. Jobbers, Dept. 2498A, 930 W. Roose- velt, Chicago. BIG Money Applying Initials on Auto- mobiles; $1.45 profit on each sale. Write for particulars and free samples. Ameri- can Monogram Co., Dept. 11, Dunellen, New Jersey. MEXICAN Feather Pictures, Christ- mas Novelty. 4"x9" costs 25c including duty, retails $1.00. Sample 30c stamps. Marquez, Apartado 1176-M, Mexico City. BUSINESS Proposition Resilvering Mirrors, Autoparts, Reflectors, Making Chipped Glass Signs. Write Sprinkle, Plater, 850, Marion, Indiana. CASH IN with Rotex Embossing Ink. Novelty Xmas repeat item. Sample, details, Free. Rotex, 257mm North Washington, Tiffin, Ohio. SIGN Letters for Store and Office Win- dows; 500% profit Free Samples. Metallic Co., 448 N. Clark, Chicago. AIR CONDITIONING BUILD Your Own Air-Conditioning Outfit This Winter! Make your own “mountain air’—for Home, Store, Office or Workshop! Live in new world of year-around health and pep! Parts and materials picked up at sma!l cost. Com- plete, Diagrammed Directions, Blue- prints, make construction simple and easy. Worth full cost, educationally alone—offers good income opportunity. Written Money-Back Guarantee. Send $1.00 (or pay Postman $1.15). Serva- tex Company, 870-MM Madison Build- ing, Milwaukee, Wisconsin. AMERICAN POLICE JIU JITSU 13 KNOCKOUT Blows without use of fists, by internationally famous Jiu Jitsu instructor. Send 15 cents. S. J. Jorgensen, 288 Maritime Building, Seattle, Washington. AUTOMOBILES ECONOMY! Performance! Mileage! Semi-diesel conversions for gasoline motors, $5.00 ир. Manufacturer’s written guarantee, Learn basic facts from free literature. Houston & Logan Conversions, 1719 Addison, Berkeley, California. $ : MIDGET Autos! Motors! Used motors for sport midgets, $4.00 up; for racers, $10.00 up. List of 60 motors, also racers, parts, 20c. Shipps Midgets, Box 543-B, Zanesville, Ohio. SEMI-DIESEL fuel oil conversion units for auto, truck, other gas motors save 75% fuel cost. Units low as $5 guaranteed on Free Trial Offer. Agents Wanted. — Free details. Dies-L-Gas, E Foothill Blvd., Oakland, Cali- ornia. MIDGET Racing Car. 100 miles-per- hour. Build with our plans, parts. Literature for stamp. Shipps Midgets, Box 543-B, Zanesville, Ohio. 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. SUCCEED in Aviation. Learn blue print reading and sheet-metal layout. Home study. Low cost. Free place- ment. Craft School, Box 687, Santa Monica, California. INEXPERIENCED workers, apply for aviation jobs now. Full salary while learning. Details for stamp. Airploy- ment, Box 553, West Los Angeles, Cali- ornia. AIRPLANES $50 Up. Terms. Trades. Motors, crackups, salvage. Complete directory 25c. Used Aircraft Directory, Athens, Ohio. .AMBITIOUS Young Men interested in entering Aviation as Apprentices, see ad on page 32. 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 50¢ postpaid. BOATS FORD and Lincoln Marine Conver- sions. Send 10c for information. Lehman Engine Co., Newark, N. J. BOOKS & PERIODICALS SPORTSMEN'S MANUAL. —The 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, RARE Antique Books. History, travel, religion. Many two hundred years old. Ten cents stamps for list, Friday A, Streator, Illinois. BOOKS That Pay. ture free. Descriptive litera- Julius, Amarillo 17, Texas. BUSINESS OPPORTUNITIES PLASTEX Industry needs manufac- turers on small scale and for big pro- duction of X-mas Tree Ornaments, 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 Christmas season now starting. Interesting booklet mailed Free, Plastex Industries, Dept. R, 1085 Washington Ave., New York. HERE’S Simplified Manufacturing Service; superior, dependable Formulas, by which you’ll easily make—sell, latest, popular money-making specialties. АЦ Lines. Duplicating, even surpassing Nationally known seasonable products. Latest “Formula Me$$enger", valuable interesting literature, Free! Miller, Chemist, 1706-D, Tampa, Florida. Accept No Substitutes! Always Insist on the Advertised Brand!

Page 161

FASCINATING business. Repair, ad- just 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. Adding Machine Equipment Service, 3601 Michigan, Dept. 2049, Chicago. 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- dal e, Inc., Drawer 110, East Orange, MAN in Fach Town to Plate Auto Parts, Reflectors, Bicycles, Fixtures, Mirrors, by late method. Simple plan of manufacturing at home starts You in Good Paying Business. Free par- ticulars and proofs. Gunmetal Co., Ave. A, Decatur, Illinois, MAKE artificial marble, glazed tiles, uncanny. Tabletops, plaques, floors, whetstones, novelties. Cement sécrets, hard, fireproof, inexpensive. Brilliant tile and liquid rubber sa mples 3c, John H. Payn, 945 Grande Vista Avenue, Los Angeles, Calif. REPAIR Upholstered Furniture. Highly profitable, full or spare time business. [Illustrated instruction book, covers niost common repairs, estimating, where to buy supplies, etc. Price $2.00. M. Swider, Dept, F. 260—19th St., Brooklyn, N. Y. LIKE To Write? Earn extra cash! Clipping and preparing newspaper articles for publishers. Simple, fasci- nating, profitable. Stamp brings details. Division 76, National Press, 3923 West Sixth, Los Angeles, California. PROFIT with new products. Make, sell, repeat. Analysis. Research. Guar- anteed formulas. Biggest catalog free. Snecial prices, leads. Gibson Labora- tory, Chemists, CE-1142 Sunnyside, Chicago. COLOR Concrete surface with chemical solutions, Make beautiful pottery without moulds. Glazing concrete. Sample 10c. Hollywood Cementcraft, B523 Wonderland, Hollywood, Cali- ornia. EVERYONE Loses Keys. Become independent. Start key registry. Particulars 10c. Identification key tags made 25c. Practical Novelty Service, us 2, 1305 Walnut Blvd., Ashtabula, io. LEARN Marbleizing; with snow-white composition imitates marble perfectly. Learn mold making, Equals rubber. No heat required. Free Samples. Cowell Institute, Grayling, Michigan. OVER 100 WAYS to make money. Home or Office. Three months of latest opportunities with our m agaz ine, “DIVIDENDS”, 25c coin. Texas Sales Office, ‘Weslaco, Texas. OPENING FOR representative— National Agricultural House, We teach you without cost. Send stamp. Box 373, Cedar Rapids, Iowa. Dept. А. AFTERNOONS free for outdoors, movies, $340 month, home. Unique plan. No canvassing. Prepare for sur- prise. Folio-C, Station D, Los Angeles. DIME brings copy 52 page magazine. Profitable plans, tips, formulas, home work offers. “Buckeye Buzzer,” 257mm North Washington, Tiffin, Ohio. When Answering IF YOU have some spare room where you can do light work, see our offer on page 155. Metal Cast Products Co., 1696 Boston Road, New York City. SUCCEED With Your Products. Make- Sell Them. Formulas. Processes. Accurate analyses. Catalog free. A. Thaxly Co., Washington, D. C. INVENTION Finance Magazine, 80-H Wall Street, New York, Year sub- scription 60c entered upon promise to pay on receipt of first copy. FREE LITERATURE describes hun- dreds plans for making money locally or by mail Gilbert Supply, 1107-M Broadway, New York. SEND for Free literature describing hundreds spare or full time money mak- One Dollar. Davis, 504 San Antonio, Austin, Texas. ENTERPRISE BUILDER for home workers. 52 page magazine. Sample, dime. M. Lane, Mountain City, Ten- nessee. SELL hy Mail! Books, Novelties! Bar- ains! Big profits! Particulars Free! . Elfco, 438 North Wells, Chicago. START home business. Make $20-$100 weekly. Free booklet tells how. Cen- tury, 1261-M, Broadway, New York. AGENTS-—To mail our literature. Good profits. Ноте business. May- wood, 149 Fifth Ave., New York. SELL by Mail, Big Profits! Operate in sparetime. Plan free. Details, W. Short, Cliffside, N. C. HOW and where to obtain capital fully explained, free particulars, Star Service, Wapakoneta, Ohio. “KWIK KASH” for home workers, 52-page magazine 10c. Gee, Box 16, Westfield, Mass. CAMERAS & PHOTO SUPPLIES CAMERAS and supplies. Free illus- trated catalog listing everytbing photo- graphic—still and movie cameras, films, lenses—at tremendous savings. Hun- dreds of bargains, new and used. АП guaranteed. We take your old camera or equipment in trade. Wirite now for your Free copy of our newest money- saving Bargain Book—just_ out! Limited edition. Hurry! Central Camera Со. (Photographic Неай- quarters since 1899), 230 So. Wabash, Dept. 12-J, Chicago. MAKE money in photography. quickly at home. Easy plan. necessary. Learn „Spare or full time. Previous experience un- Common school education sufficient. Interesting booklet and re- quirements free. American School of Photography, 3601 Michigan Ave., Dept. 2049, Chicago. INCOME From your camera instead of expense. Low cost home course teaches you to make photographs for magazines, newspapers, advertisers. Tremendous demand. Earn good money wherever you live, Free book. Universal Photog- raphers, Dept. A, 10 West 33rd St., New York. LEARN Photo-Engraving! Equipment, Instructions .95. Dicharry, 1015 Peniston, New Orleans. CAPITAL RAISE Needed Business Capital. We show you how. rite fully. Enter- prise Bureau, Syracuse, N. Y CARNIVAL GAMES AND Merry-Go-Rounds earn Big Money—Outhts. supplied. Catalog 10c. “МоогеМайе,” Lapeer, Mich. Advertisements Please Mention December Modern Mechanix CARTOONING, Sketching, ing plans. eee Company, Dept. M1, Gassaway, W MAKE Beautiful Artificial Marble : Products. uaranteed Instructions. | CARTOONING etc.—46 lessons. 600 illustrations, including: drawing paper, pens, pencils. $1.00 Complete. Fraba Service, Dept. MMI, Cashton, Wisconsin. CARTOONING & COMMERCIAL ART - ART Magazine. Helps you sketch human figure, paint, model, carve, car- toon, sell drawings, exhibit, form clubs.” Regular 25c copy for 10c while samples Art Headquarters, 18 E. 48, New York City. CARTOONING COURSE: 30 i trated lessons, over 500 drawings. and pencils, $1.00 complete, postpaid. Scorel Studios, Box 748-M, Hollywood, alt EARN cash income, copying and dupli- cating simple cartoons for advertisers. 3-N Service, Argyle. Wisconsin. CHARTERS DELAWARE Charters: Complete in- corporating and organizing service $35. Submitted forms. Chas. Guyer, Inc., Wilmington, Delaware. DETECTIVES DETECTIVES. Make Secret Investi- gations, Experience unnecessary. De- tective Particulars free. Write, George Wagner, 2640-V Broadway, N. Y. EDUCATIONAL & INSTRUCTION DALE CARNEGIE’S HELE IN PERSONALITY BUILDING is now open to YOU. Read the course, "PUTTING YOURSELF ACROSS,* as compiled from the works of DALE CARNEGIE, кїлїп in the Decem- ber PHOTO FACTS. 22 W. Putnam Ave., Greenwich, Conn. MEN Wanted—Learn Tool & Die Making. Automatic Screw Mach. Machinist Trade. Big Demand. Actual Experience Expert Supervision, Write for Free Book “М”. Allied Screw Machine Co. Inc. School Div., 603-9 Lake St., Chicago. MEN—WOMEN. Get Government Jobs. Start $105-$175 month. Prepare now for next examinations. Common education usually sufficient: Ful par- ticulars—list positions, FREE. rite today. Franklin Institute, Dept. K 59, Rochester, N. Y WANTED Immediately, Men-Women, age 18-50, qualify for Government Posi- tions. Commence $105-$175 month. Common education sufficient. Valuable information free, Write, Instruction Service, 234, St. Louis, Mo. STREAMLINE-SCRIPT (Easier than Shorthand). Especially for Students, Reporters, Business, Professional, accurate, readable. Easy Studio, 33 Fullerton, house-wiring. 64 diagrams, $1.00. tric Maintenance Service, Box 7608, -Kansas City, Mo. ELECTRICAL EXPERIMENTS ELECTRICAL KIT, $1.49! light mile range. Arc furnace. glass, metal. Weld iron, brass. tan rays. Dozens others. Complete with goggles, instructions. "Works from house light current. Electrical Salvage Co., Box 524-B, Lincoln, Nebr. ELECTRICAL SUPPLIES HUNDREDS of new, unusual, hard- to-get electrical items, replacement parts and supplies. Send for free wholesale Catalog. Autopower, 412 South Hoyne Ave., Chicago. 16 жэ

Page 162

ENGINES, MOTORS, ETC. WINDING Data, 225 motors, single aud three phase. Price $1.00. Motor Data Service, Box 7631, Kansas City, Mo. cycle, motorwheel, washmachine, others. Shipps, Box 543-M, Zanesville, Ohio. : РОН INVENTORS PATENT YOUR IDEA. Write im- mediately fot two free books, ''Patent Protection" and “When and How to Sell an Invention." Fully explain many interesting points to inventors and ilustrate 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-P Victor Building, Washington, D. C. INVENTORS—Time counts in apply- ing for patents. Don't risk delay in patenting your invention. Send sketch or model for instructions or write for new 48-page Free booklet “Patent Guide for the Inventor’. No charge for pre- liminary information. Prompt, careful, eficient service. Clarence A. O'Brien and Hyman Berman, Registered Patent Attorneys, 28-M Adams Building, Wash- ington, D. C. ENGINEERING group announces con- fidential consulting service to help in- ventors solve mechanical, electrical, electro-chemical problem; laboratory; expert technical staff; reasonable charges if по assistance rendered no payment required; address Inventors Research Service, Old Lyme, Conn. WE SUCCESSFULLY SELI, 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 matters. Registered Patent Attorney. L. Е. Randolph, Dept. 341, Washington, D. C. ibi AL Fas d ual a Lad es 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. Thaxly Co., Washington, D. C. MIMEOGRAPH INK! Make your own. АП colors. Simple formulas 25c. Dupligraph Company, Rochester, Minnesota. CIGARETTE Roller rolls once, Size adjustable. Plans Money. 5527 Vickery Blvd., Texas. FORMULAS—Latest Money Makers. Literature free, D-Belfort, 4042 N. Keeler, Chicago. FORMULAS—AI! kinds. Catalog Free, Tllinois. GAMES & ENTERTAINMENT PARTY-STUNTS (87) explained with pictures. Easy, Entertaining, Mystify- ing. Funny. 50c. Studio, 33 Fullerton, Albany, N. Y. HELP WANTED USE $500? Raise Canaries for us. Splendid sparetime money maker; fascinating work. We supply singers and buy back. Write for free particu- lars. САМЕ; Вох 44-A, Wood- Guaranteed. Kemico, 67, Parkridge, HYPNOTISM HYPNOTISM. Complete 20 Method Course 25c. Lonk Institute Hypnotism, D-1313, Palatine, Illinois. INVENTIONS A. P. C. PATENTING Plan. two-thirds. Ultimately stronger patent protection. Booklet free. American Patents Corporation, Dept. 5-E, Wash- ington, D. C. А INVENTION S—Patented, Unpatented, Bought outright, royalty. Write Arel- lano-Power Company, 53 West Jackson, Chicago, Illinois. INVENTIONS sold. Straight com- mission basis. Write Commission Sales, Box 31, Augusta, Maine. INVENTIONS WANTED SMALL INVENTIONS WANTED by manufacturers. ГІ help you sell your invention. Write for free circular. . Hull, L-7829 Euclid Avenue, Cleve- tend, Ohio. INVENTIONS Commercialized. Saves uU ented or unpatented. Write Adam Fisher Company, 582 Enright, St. Louis, Mo. MACHINERY, TOOLS & SUPPLIES FREE—Bargain Catalog, handy elec- trical tools, drills, motors, machinery, accessories; for mechanics, craftsmen. Paramount Products, 245B Broadway, New York. MAGIC TRICKS & NOVELTIES WE SUPPLY every noted magician, Large Professional catalog 25c. Holden, 222 West 42nd St., New York. MALE HELP WANTED silently, automatically. ciple. Easily installed. attention. Priced dollars less than other Free demonstrator furnished E Kant-Slam, Dept. 2-63, Bloomfeld, Indiana. No canvassing. easy. Experience unnecessary, Val. uable demonstrating equipment, actual samples Free. . J, Graves, Pres. 1300 Harrison, Dept. Z-819, Chicago. STEADY Work—Good Pay. Reliable man wanted to call on farmers. No ex- perience or capital required. Pleasant work. Home every night. Make up to $12 a day. Wonderful new proposi- tion. Particulars Free. Write McNess Co., Dept. 4, Freeport, Illinois. MALE—INSTRUCTION DETECTIVES. Work home or travel. Experience unnecessary. Write, Ameri- can Detective Institute, 2640-T Broad- way, N. Y. MIDGET AUTOMOBILES BUILD a Midget Miller Racer. Com- plete plans for constructing tbis authen- tic midget automobile appear in the new 1938 edition of How-To-Build-It along with many other interesting home and workshop plans. Send 50c for this 148- page book to Modern Mechanix Publ. Co., Greenwich, Conn. MIDGETS — Motors —Parts— Plans. See ads under "Automobiles". Shipps Midgets. MISCELLANEOUS TRIANGLE chart solves triangles. Faster than Trigonometry. Review of Mathematics included. Sold in some hardware stores. Send 25c in silver. P. O. Box 764, Detroit, Mich. BURIED TREASURE, Minerals, free booklet, photographs. Fisher, Palmer Bldg., Hollywood. MODEL RAILROADING BUILD a Model Railroad in 00 gauge Freight Car Body Kits $1.00, Westbrook Co, 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. THE Latest Catalog—Locomotive, gas, steam engines; castings, model supplies —25e, efund on order. Howard, 1-2417 М, Ashland, Chicago. ENGINE Catalog 20c. Particulars Evraymesco, 28 N. Clinton, MODEL Plane Gas Motors, $5.95. Dicharry, 1015 Peniston, New Orleans, MONEY MAKING OPPORTUNITIES Service, Box 337, Alice, Texas. 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. SEND 15с for illustrated used Motor- cycle catalog. Bargains. Largest stock genuine Indian parts and motorcycles. indien Motorcycle Sales, Kansas City, Mo. NEW-USED parts, new accessories, new auto parts. Big savings lists 10c. Comiskey, 3852 Addison, Chicago. OFFICE EQUIPMENT TYPEWRITERS, multigraphs, address. ing machines, adders, dictaphones, dup- licators, sealers, folders. Save half, write Pruitt, 553 Pruitt Bldg., Chicago, STENCIL DUPLICATORS. Full let- ter size. Color work. Perfect copies. Lowest price. Dupligraph Company, Rochester, Minnesota. OLD GOLD WANTED CASH for old gold, teeth, watches, jewelry. 100% full cash value mailed shipment received. Satisfaction guaranteed or articles cheerfully re- turned. Information free, or ship today. Chicago Gold Smelting Company, 300-C Champlain Bldg.. Chicago. OLD MONEY WANTED $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 Roy, N. Y. PATENT ATTORNEYS PATENT YOUR IDEA. Write imme- Invention" form. Prompt service, reasonable fees, thirty-seven years' ex- perience. Avoid risk of delay. Address Victor J. Evans Co., Registered Patent Attorneys, 920-P, Victor Build- | ing, Washington, D. C. Accept No Substitutes! Alwavs Insist on the Advertised Brandt

Page 163

INVENTORS—Time counts in apply- ; ing for patents. Don’t risk delay in | patenting your invention. Send sketch i or model for instructions or write for new 48-page Free booklet “Patent Guide for the Inventor", No charge for pre- liminary information. Prompt, careful, efficient service, Clarence A. O’Brien and Hyman Berman, Registered Patent Attorneys, 28-M Adams Building, Wash- ington, D. PATENT Your Invention with this re- sponsible firm of Registered Patent Attorneys. Deferred payment plan. Over 62 years’ experience. Write for two free books and “Certification of Invention.” Snow Co., New Patents Division, Snow Building, Wash- ington, "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. HAVE YOU a sound, practical inven- tion for sale, patented or unpatented. If so, write Chartered Institute of American Inventors, Dept. 5-A, Wash- ington, c PATENTS INVENTORS-— Time counts in apply- ing for patents. Don't risk delay in patenting your invention. Send sketch or model for instructions or write for new 48-page Free booklet “Patent Guide for the Inventor". No charge for pre- liminary information. Prompi, careful, efficient service. Clarence A. O'Brien and Hyman Berman, Registered Patent Attorneys, 28-M Adams Building, Wash- ington, D. C. PATENT Particulars and Blanks, Free: Government-Registered Patent Attorney 31 years. ie oie Buck, 3d, 629 F, Washington, D. PATENTS. Booklet ire Highest references. Best results. Reasonable fees. Watson E. Coleman, Victor Build- ing, Washington, D. C. GET Your Own Patents. Legal blanks, complete instructions $1. Cudding Sons, Campbell, California. PATENTS WANTED INVENTIONS Commercialized. Pat- or unpatented. Write Adam qo 582 St. о. Enright, PERSONAL DALE CARNEGIES HELP IN PERSONALITY Т BUILDING is now open to U., Read the course, "PUTTING Y OURSELE ACROSS. A as compiled from the works of D ALE CARNEGIE, beginning in the Decem- ber PHOTO FACTS. Be sure to get your copy—on all newsstands October 15th, or send 25e in stamps or coin to 22 W. Putnam Ave., Greenwich, Conn. GUIDE your future. Succeed in Busi- ness, Marriage, Friendship. Astrologi- cal analysis. Inspirational. Beneficial. Send 25 cents, birth date. G. Wallace, 52 Elm, Plattsburg, New York. SHOOTING High in this Game of Life? Interested in Greater Personal Power? Write today! Johnston, 257-F North Washington, Tifin, Ohio. DON'T suffer from falling hair—bald- ness! Write today for FREE details of HAIR HEALTH. Globe Company, Grand Forks, №, D. PHOTO DEVELOPING 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. When Answering Chemists Aid Aero Development Chemistry plays an important part in aviation progress and air transport op- erations as shown by this photo of an American Airlines chemist analyzing gasoline and oils used by the air line. ROLLS DEVELOPED—Two Beauti- ful Double Weight Professional En- largements, 8 Never Fade Prints, 25c. Century Photo Service, LaCrosse, Wis. ROLLS DEVELOPED-—25c coin. Two 5x7 Double Weight Professional Enlargements, 8 gloss prints. Club Photo Service, LaCrosse. Wis. RADIO Engineering, broadcasting, aviation and police radio, Servicing, Marine and Morse ‘lelegraphy taught thoroughly. All expenses low. Catalog free. Dodge’s Institute, King St., Val- paraiso, Ind. RADIO Experimenters, long distance tube and crystal sets. Plans to build and supersensative crystal 25c. Radio- lite, Kindred, N. D. RESIDENT SCHOOL LEARN Fascinating Profitable Profes- sion of Swedish Massage in great Кезї+ dent School in Chicago. Write for Free illustrations of Massage Technique. Low Tuition, The College of Swedish Massage—1601 Warren Blvd., Dept. CI. Chicago, Illinois. SALESMEN WANTED GOLD Reflecting Window Sign Let- ters. Penny Each. Large Sizes. Easily Applied. New Styles. Absolutely Beautiful. Free Samples. Atlas Sign Works, 7941G Halsted, Chicago, Ill. WANTED COUN T Y DISTRIBU- TORS. Excellent opportunity for earnings. Nationally advertised prod- uct. Large company. Dept. 251 Fyr- Fyter Company, Dayton, Ohio. SELL, grooved felt back changeable signs with double prong celluloid letters to all stores. commissions еше Press, #124 White St., New “or SPECTROSCOPES LARJARGRAPH Reprints: Five (5x7 Enlargements) 25c. Cardinal Photo, Summit, POULTRY BIG MONEY in poultry this year, Read Poultry Tribune, the big monthly maga- zine that tells how leading poultry raisers make money. The only poultry magazine operating its own experimental farm. Five years $1.00, one year trial 25c. Poultry Tribune, Dept. C-92, Mount Morris, Ill. PRINTING 125 LETTERHEADS 84x11 and 125 envelopes $1.00 postpaid. Benneville, 907 West Roosevelt, Philadelphia. QUALITY Printing. Lowest Prices. Samples. Tucker Agency, Box 63, Indianapolis. PRINTING EQUIPMENT BUY your printing equipment from one who started a large printing business with a hand press, Presses, type and supplies. Catalog free. Globe Press Company, Dept. C, 2608 Lawrence Ave- nue. Chicago. RADIOS FARM-CITY radios Save half. prices windchargers, power plants, ac- cessories. Marco, 1250 McGee, Kansas City, Mo. PLANS 18 Distance Crystal Sets—SW record 4250 miles, with ‘“‘Radiobuilder” —25c. Laboratories, 151-K Liberty, San Francisco. RADIOS & SUPPLIES NEWEST radio, electrical books, 20c to $1.00. Amazing values. Catalog free. Electronic Publishing Co., Box 323-D, Lincoln, Nebr. RADIO & TELEG RAPHY. $7.95 complete. » 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. Advertisements Please Mention December Modern Mechanix Agents free offer amazing | ; Best experiments, Campbell, California. TATTOOING SUPPLIES TATTOOING Outfits, Supplies—Cata- logue. Guaranteed Remover. “Waters,” M-965 Putnam, Detroit. TELESCOPES, MICROSCOPES, ETC. TELESCOPES, Microscopes, Binocu- lars. Lowest prices. Optical catalog free. Brownscope Company, 234 Fif th Avenue, New Yor TEMPLE Field Glasses, worn like spectacles, postpaid $1.95. * Booklet 037 free. Delmaco Products, Box 1123M, Wilmington, Del. TELESCOPES, Microscopes, lars, Mineralogy, Chemistry. free. Teeko, Evanston, Illinois, BUILD Reflecting telescopes; catalog free. Instructions 10c. Оре Labo- ratories, Larchmont, VENTRILOQUIST LEARN Ventriloquist Art, Low Cost. results. Easy. Éither Sex. Quickly learned, Satisfaction. Details reé. Apex, 221 East 31st, N. Y. EARN Ventriloquism by mail; small cost, 3c stamp brings particulars, Geo. W. Smith, 125 North Jefferson, Room 677, Peoria, Ш. WELDING "MAKE Band Saw from old Auto Parts"; “How to make 15-100 ampere A. C. Arc Welder’; “How to build a real lathe”. Complete drawings, plans, constructional details, 20c each. All three for 50c. Federal, Box 344, Dept. 23, Indianapolis, Ind. DODGE generator makes 150 amp. welder. | Complete drawings, instruc- tions, $1.00. A, Monroe, 47634 Wa- basha, St. Paul, Minn. WIND ELECTRIC PLANTS GENERATOR Propellers, expertly de- Signed at factory prices. niversa] Aircraft Co., Fort Worth, Texas. Binocu- Catalog un E m n 16 e

Page 164

Add Microscope To Camera [Continued from page 143] light for photomicrography is monochromatic, consisting of a single color, Therefore filters are commonly employed to absorb certain of the colors in white light and to transmit others, Wherever contrast in the visual image of an object depends mainly on color contrasts, then a filter is essential in order to approximate thesc contrasts in the photographic print. For example, suppose we are dealing with a section of animal tissue in which the predominating stain is red. | duct ог an artery may stand out, as one views the section through a microscope, because stained a darker-red than the surrounding structures; the eye discriminates various shades of reds and contrast is afforded. But red photographs black by white light and all of the many hues of red will affect the film more or less equally. А picture so made will be very disappointing—a dark succession of grays and blacks in which contrast is lacking. In selecting a color filter, choose the complementary color to that predominating in the subject. In this case where the stain is red the complement is, of course, green. Make the picture with а green filter and the result will be à vast improvement; a lighter picture with good contrast. Color filters may be purchased either singly or in sets, but they are very easy to make. Cut some glass plates ot buy lantern slide blanks and between two of these, thorough- ly cleaned and dried, place а sheet of colored cellophane, then bind the whole around the edges with gummed tape. Arrange a holder or stand so that the filter comes between the light source and the microscope mirror and success is assured. By experimenting on the same subject with filters of different colors the variation in results and the improve- ment in pictures will be surprising. There are still other experiments to do. See whether or not the lens of the camera can be unscrewed. If so, try taking pictures without the camera lens or with the camera lens in place, but with the eyepiece of the microscope re- moved. Both of these methods are recommended in order to get lower magnification or larger field, as is necessary when an entire view of a relatively large object is required. Inexpensive low power eyepieces are obtainable; they are known as projection oculars because they are employed in microprojection machines. These are best of all for most photomicrographic work. Then again there are the low power objectives. In fact, for very low magnifications, no microscope at all is used, a lens known as a micro-tessar being screwed directly into the camera shutter. As to types of plates or film, any will do, though pan- chromatic gives best results. By all means do your own developing and printing; it's not only far cheaper and more satisfactory, but is grand fun. The kitchen, bath room or cellar may be converted into а darkroom by covering the windows with heavy cardboard. ' Prepared developers and fixing salts are obtainable from any photographic supply shop. Use slow, panchromatic emulsions and develop in complete darkness. See the article, “Develop Your Own Pictures", which appeared in the “Modern Photography" section of MopERN МЕСНАМІХ for November 1937. Photomicrography is not only an unusually interesting hobby, but has excellent commercial possibilities, too. The experimenter can profit by his experiences and convert his knowledge into a profession which is in great demand by both science and industry. The Arabian camel can carry a load of 500 pounds, or even a heavier weight, and travel with it 25 miles a day for three days without drinking. Visual education, by means of films and slides, is widely used in publie schools of Rochester, N. Y., home town of a big camera and film in- dustry. ADLETS FOR HOBBYISTS (See regutar 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 aproval applicants. Big illustrated lists included. Kent Stamp Company, Box 87-Z (G. P. O.), Brooklyn, N. Y. LIBERIA Jubilee Set—-Complete! Beautiful bicolored ship and landscape—commemorating Liberia's founding. Cata- logues 30c, Plus new bicolored triangle, and thirty attractive Dictorials-—lÜc with Double Premium Approvals. Inquire regarding Free Airmail Collection. Tru-Value Stamps, Box M1412, Hartford, (5) Connecticut. BIG 5c offer! Consists of Costa Rica, Ecuador (Large Commemorative), Jamaica, Haiti (Aqueduct), Cuba, Zan- zibar, Indo-China, 10 diff. Mexico, and 15 diff. China—all for Sc to approval applicants. Maynard Sundman, Dept. D12, Bristol, Conn. FREE—Coronation Error which astounded British Empire, also correct variety—Absolutely Free—providing your pur- chase exceeds 25c from “double-premium” approvals. Bar- gainstamps, Box 5147, Los Angeles, California. PRODIGIOUS GIFT! German State, Selangor, Perak, Negri Sembilan, Bicolored Banana Airmail, Siberia—Free with Approvals! Postage 3c. Saxon Company, 3 DeKalb Ave., Brooklyn, N. Y. MAGNIFICENT Mourning Stamp; complete issue com- memorating bloodiest period in history with 20 additional commemoratives only 10c. Friendly Filatelists, Box 4428, Philadelphia, Penna, CORONATION commemorative plus Diamond shaped Air- mail, absolutely Free— providing your minimum purchase over 25e from approvals. Progress Stamp Service, Kirk- land, Washington. UNITED STATES—45 different 10c. Free 25 different with approvals. Enclose 3e. Sidenburg, Baroda, Mich. SAMOA! Nineteenth Century Stamps! Issued when in- dependent kingdom! High catalogue—Plus thirty attractive pictorials, new bicolored triangle, Commemoratives, Airmails —10c with Double Premium Approvals. Inquire regarding Free Airmail Collection. Tru-Value Stamps, Box M1412, Hartford, (6) Connecticut. GIGANTIC Bhopal Triangle, Turks Caicos, $5 U. S., Caymans, genuine Baden. Everything 3c with approvals. Viking, IMM Hanson Place, Brooklyn, N. Y. FREE!!! Coronation Set. Postage 3c. Roberts, 901T Eourth, Baycity, Michigan. FREE! 50 different with approvals. St., Medford, Mass. Tupper, 71 Fulton COINS $5.00 TO $500.00 EACH paid for Old Coins. Keep all eld 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. COINS, Beadwork, Indian Relies, Minerals, Books, Curios, Stamps. Catalogue, 5c. Indian Museum, Northbranch, Kansas. M CALIFORNIA gold quarter size 27c. $14 size 53c. Large Illustrated Catalogue 10c. Norman Shultz, Salt Lake, Utah. INDIAN CURIOS 12 ARROWHEADS, Spearhead, Wampum, Scraper 99c— Pestle 98c—Tomahawk 88c. 20,000 Bargains. Photolist 10c. Museum, Rutland, Illinois. INDIAN CURIOS. 100 good ancient Arrowheads $3.00. Tomahawk Head 50c. Illustrated catalog 5c. Н. Daniel, Hot Springs, Arkansas. AUTOMOBILE PHOTOS PHOTOGRAPHS, World's Costliest, Speediest Automo- biles, Dusenberg, Bugatti, Mispano, Isotta, Alfa, Mercedes, Tatra, Horch, etc., Quarter-plate 12 for $1.00, List—10c. International, Box 329, St. Cloud, Minnesota. 164 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 165

Float over cobble stones with ON 1936 Packard smoothness. Sail | over curb stones with hardly a jar. Ride miles farther and faster with- m" ——- out getting tired. Anybody сап pe Ll attach KNEE ACTION quickly 22 N io any make or size blcycle in s minutes Peon a wrench. Nothing to wear out or. get out of order. COMPLETE Patents applied for. Lasts a lifetime. Be first in your town. SEND NO MONEY!—Rush postcards for your KNEE ACTION and instructions. Pay postman only $1, plus few cents postage on delivery. If al . not delighted in 15 days, return and well Floating ^ refund your dollar. We include FREE deta’ Ride s 5 on how to make monev selling to friend PACKARD KNEE ACTION CO., Dept. Z-963 Cincinnati, Ohio V2 Price 4306 Marburg Ave. Only 10c a Day Bavo over 34 Míg.'s Огірі, Price on oll standard up-to-date office modele SEND NO MONEY fBensationnl saving on all late models coi jetaly refinished like new. FULLY GUA NTEED. Big Free Catalog showsall makes in ful colora d postcard for lowest prices: SPECIAL PORTABLE BARGAINS = Brand New FEATHERWEIGHT—Latest Model Portable—up-to-date wireamline featuree—now offered at amazing low price. Fully Guaraus teed—10 day trisl—only 100 в day. details sent freel Free course In typing included. i international Typewriter Exch., pant. Yeas Gov TT JOBS IOV T JOBS li ati anl |, mh Г SAT itl m Thousands of openings yearly. Men-women, age 18-50. Start $105-$175 month. Get ready now for next entrance test. Get our new plan—mailed FREE. Write, INSTRUCTION SERVICE, Dent. 233, ЕЕС САЙ St. Louis, Mo. For those who can't afford the time and expense of a 4-year college course, Bliss offers a condensed ONE -YÈAR. residence training, combinin and Practice, 45th year. CATALO essential Theory ON REQUEST! ELECTRICAL SCHOOL * Washington, D. C. BLISS 392 Takoma Ave., at Makes lumber, shine gles, lath, ties crates, bores, cases, ali forms TURN TREE INTO 8 MONEY WITH A BELSAWU 00 Three capacities: 10, 14 and 20 feet. Accurate set works, posi- 8]. tive dogs. Hand or power feed. Runs on low power—Many owners use old auto engine. Pays for itself quickly—thousands in commer- cial service, everywhere. Write for free lumber handbook and catalog of mills, supplies, tools, saw tables, and_woodworking equipment. ., BELSAW MACHINERY CO. » 834-L Davidson Bldg. Kansas City, Mo. Fascinating book on scientifically solved true crime cases gent absolutely free to those over 17. tells how to get into Scientific Crime Detec- tion. Home Study. New opportunities, Travel. Steady Employment. Experience not necessary. Very easy terms. SCIENTIFIC CRIME DETECTION INSTITUTE OF. AMERICA, INC. € & о ваз. A J. T. Burdette, Pres. Dept. 30M7, Huntington, West Virginia When Answering Advertisements Please Mention December Modern Mechanix Also. Are Ou TIED TO YOUR EL Are you in a rut, tied to a factory job, with little or no prospect for ad- vancement? Will you be doing the same thing 20 years from now? pu por train for а etter job, more pay eres and prosperity? Pre- pare now, to enjoy everything that big- ger earnings make. possible, a D 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 a 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 MONEY BACK. Start NOW and get the training. Prepare Size 20 x 28 Inches - TODAY! Time is money! FURNISHED Don't delay! No obligations! H Send me your free book, "Successful Draftsmanship'' and ex- и Plain how you will assist me to а good position as a draftsman, $ = в training UNTIL COMPETENT and until assisted to а, position, for more pay and a better job. Free Book. Namen- ~ Аве OR YOU GET ALL YOUR Complete Outfit Send the coupon below ENGINEER DOBE, Div. 4739 Libertyville, Ш. = Address

Page 166

OUR "SENSATIONAL NEW 1938 CATALOG NOW READYI NEARLY 800 PAGES OF UNUSUAL NOVELTIES; SEND 10c FOR I | BRO DCAST thru your radio TALK - SING - PLAY BROADCAS the hon-e—1isect Fadio stars, "Ben Bernie Made especially for attached in a jiffy Ww your vette on programs coming through your own Tadie sei—mahe. ar wise -eracks practice crooning, or a “Шу Valec. World Mike home lout taols, iie Telegranh vet у o Martice Хеб or ouncements from any part of Гра ро josh and mystify friends. Imilate HN radio acting. ete. Do a LU Ы n f gorwaasu. Wooten bate? zT А БИ ke; Western tU. Not a toy. Pnt оп your own pro- home. parties. Barrels of (un WORLD WIDE 42 ‘out 15 19 600 mel. їз. foreran tiav grams at f: ete. fo operate. _& Price Postpai ALL WAVE Teremtion With зше Completely "cd КЧ Fst With ue famons “Wert Ure Dollar Pocket Tus HITTER that sends out First again! de Radins. tabs TRANS oniy $1.00, plus 10c postage. Note these sen ж Сап be picked up on ж Not a'Mike, but a complete Bro. * Complete with Key, In МИ Form ж Plugs in to any AC-DC * Uses 2 oscillating iubes Complete Trantm te Sela. short O chuh af. $1.00 plus 10c post. Tubes (uses 2) Each 50c loud. Qut i * Eas) in Nu. Tuaran] 5 : : MIDGET POCKET RADIO $1.00 Listen to Music Programs ond Sports tverywhere You Go—Loud Толе Geol Tereptian with Beautiful Y lone! The amazing midzel poekel radio gives sou ай the enlertainment of @ типо whorerer you are—in the country, in SE i camp. ofice, ele зону е Phone & Rad die sit Earphone. Eagle-Eye Vision Six Power Oni aser Onutoors. пагш'е study, Shorts. lanking at (he moon, only эзет 14 Y 38 turn the vd crystal radio, then the the All Ware World dio. and NOW a gem e»acex by wireles onal Features; | WONDERFUL x RAY 10c GREAT CURIOSITY! епу seo nes In the fingers. lead ma evea the Mesh seems М! rent, Always ready for ату 10c, 3 for 25e Silent Defender pocket, wi. How TO adcasting Set A MIDGET RACER from A for à few dollars. Camprete Pea Shooter Peamatic autamatie Cigaret Pistol Look like a dan- acrous automate. but pell wieter and Cap Pistol pipi avtomat сай DT амата CS eta Me e Мы Rus e A P M АШК ҮЛ SUME MES Куш BRT out ro Jonatha SUR nets Ri Annen anet Aera borrar. 396 rg eut Welster- отус sh quate Air Pistol Rich Powered. ac. пе msta. Fires] Shot "and ` alu Stvles, $2 50. ot; 35.00

U-JITS Шш Vat seien LEACH. DON'T GE GULLIED 30c ала оета [n nst armor headlock; down, double i Btick ` attack ar Revoltei Mearance Al scare aburlar. Takes 22 Cal, Dlank Ег гез obana Uaving around эсен touther waivers Fine ror hal Years. size work, si Te iet блу Soc.

eic, Tea yi 31.00. tcov boy type) Bde. for 3 «i The one lu: жап be built for а few Жум а ars ain? Rent депи vla "Eis L| Permite fo sbamperea, lustrations. €^MPLETE асан oniy” ACHT CAPS ek news. How To Be A Police Reporter << реч.

Quartermaster - Navy ccc Marine - Army - Aviation Handsumely embosced NY ын Finis made (o resemble rings womi by men in DU. хепипеп service. Jumbo accurate détail, wilh hejvy machine encrased neTicun Eagle. State Glee and ring desired. В. ЧЕП APPEARANCE Sterling Sliver 51.00. 14 it God Plate $1.75. Am

Hinner Sportster Stinson Reliant FLYING MODEL AIRPLANE KITS the bumps. Diane Doctor Cortuteate Liars License Dean Certteue Бок License Divorve, Cert fi "i License Geld Digcere Boowcegeer, Diploma 3 23, rice 10с each WHOOPEE CUSHION Whoopee Cusmion їз! mnue ӨГ rubber. in. Aaea Tikes bal oan and then placed опа Chair," сенси. зеде When the viellm: forth noises esten bebrterin oo:

your friend will yet à. violent Shock. Taueh them оп the hack, them (umm. They мэн dut (ne. thev sit on, it. Under а shee! à mouse, Ure t au а “UCA window. Hundreds of ‘uses. ONLY ELECTRIC MOTOR 15 Am Kiecirie Motar far 10с- ~ounag mast unbelievable bul jt [s pei (есу erue. We send all the parts packed in à neat boi with (ull Instructions for bur afew minutes, And ki OW 1OY: Len Lit seedy Runs . & or similar dry Date Y iana- па, Four unice Ii price gf 13c оеп ат КЕЧ ond whch Ioka hues Sigaretie will At anto, your сюрсе Dighisevery time. Yourcnoice ONL ADDRESS ALL ORDERS FOR GOODS ON THIS PAGE TO 1938 CATALOG : 600 PAGES OF UNUSUAL sweat band, god and brase hutuans . white and soie n Photo Ring Shull&Crossbones EPCS inu. Meus NU ring. о and tuhy even. noolar 256 Joke “far” nume heez NY РАМУ n rette All about racer fears, transmis: s. йг Wack га, з. track rem Tons. uiueprin blans. MOTOR ro You WIE a1 low сол. creasing speed, ate.. etc. Cram: med 4 jammed full o information. lana & Dlueprinta. 25e. 35: хо hey ei when L takes a threes

WATCH IT CHANGE COLOR! pnt. of these тов wonder of all s Walch Study its hi Hawker Fighter Tao. montis cttam med io аву arid се sefe arrivi Ne trai food Copy ef Ша эсе kit. E nan. С Mit. Price Only Price Only... €9M иси төгө mina, а“ nud A I alal safe lock and Vault Bank. June dini the three umtiers оле open anit just like m Bie and room» Swe! to. keep vour jewelry ete. ln. Conus of heavy Siin Sed and Black trimmings. Tull Бег. fect hilo TASSO йсй ано Weddiag p " Coruscrew: à ет? ЧА N Pached in a box. with compete dirceions for ovening. Price. Dod INSERT A COIN AND OUT COMES A DELICIOUS CHOCOLATE BAR Thrift Bank and Slot Machine This sensational new-type bank yours—yours ta have and to hold—without any enst, — Just think of having this handy bank sro:nd and or а penny, M or dime dropped in—out comes а chocolatc bar. all wrapped up! youl find that t fills wn Lease the bank aronnd the hou and With money while you're cone. HOW TO GET YOUR BANK FREE! This sloL-maehime hank cannot ke bought. There Is Just one way to get il—send $1.00. for 7M chocolate bars and v will include the bank freel Made of sheet metal with regular lacked door to уо: ean прен. remove money and reflll with ке, On the front is а slot (o drop coin in, and а plass v showing bar. Red. yellow and sree Send а doller hill ($1.06) for the 70 bars aud gel the bank FREE. EXTRA! Tí sou daury, we'll add, wilhout cosi, our biz 195 GOU-pace novelty cetalor, 3500 illustrations, аЛа ЕСТИП Bors! BOYS! 35c Althorn ам рны їявотпагуе1лиз1ү cheap, 1Usauize eff iene $1.25

inder ine bed Jam Tem of пф friends. The ENTRILO QE: litte instrument, in the math nut t, used Bird Calls. ete. Tt. "Never f; instan d Commie with 4 Rims, J расилте of printini pa- per-printne Tramo with and 8 хыпрїу of chemicals fa! de. winE and tarming oui f shed full penton Instructions жө Dlalniv ng, complete өш! tar only JAE мин а (er postage and packiot, ERU film packaze of mye fims. EN рип Ореп Any Lock Did yau ever lace or forret vour kev Provahly mane Umes Don tenrrvan e aeu y Ч maner). од Apply vorne t ing Watch sn уот сар fell umo at ТЕМ, Paint nushbuitone, Size of a mo (aec staan, en. Every! ward Tesamen iS thine пом Tuck __ kesther cover, geld edaes. youn, "нашу find themi 39 handy Grab vou ll ч, Carry them GS MASTER KEYS Price 25€ И өэ am lav, Tnrec "minut Play im 3 mine 3 Piere АТА d

American Legion En ү GLE A regular wate at one third Remsvable ens Because we have agreed Dame. ang save vou (he Timm. "we (An кї! а jew price, with олег "bi mmartest, ms vou

‘Automatic Mouth Organ y ine "Thewhnie towne me. Beat ant a tune with voir feet. 3101llusiratiore ngorat ne taining but 1. Drass band In oneni исем senna: inthe musieal w Pie and givin ot бле to t uon s Town Saved

came th fost. sma Toy Busy to onerat ch, no lever to pull. тош! le "Guaranteed for 5, ining caleulstor and. . Consuueter of steel hdura hity and аига! а RS rima diattat fReverae Wave. Как! to тшме, Wal at he wh та coer! rest siers wIfhnut 3 low to walk ta musie. Тасехсгондгот atens. id Пеуселе Turns, the тле, kes. uig Continental. A Kisa daneg. the M: the Culleco Rhumba, tre Carlo, Charleston, ete. thou! Inconven, Vest Pocket Secretary Lead, peno ір Орел 12 ncn tulerat cided into IGS qup to pocket кїйє of engineers. PL Art of Dancing. тше, Famous Kern. mujuplying ealeula- ' 50с hs d

JOHNSON SMITH & CO. DEPT. 155, "DETROIT, MICH. NOVELTIES Send 10c for 600 page paper covered edition, or 25© for complete DELUXE cloth bound library edition a Th. ds of useful gadgets, time savers, novellies, joke articles, puzzles, magic tricis, seeds, books, radios, make up goods, cameras, Jewelry The est ae airplane & Rost Mts. tobacco, 150 ‘telegraph sel. water wings, live chameleons & alligators, luminous paint, gaod luck novelties, $1.50 adding machine, 25c radio's fre 00 ra transmitter. 25c mike, 26c electric train. 10c airplane kits, sweater emblems, freak seed plants, lelescopes. 39e field glass, experimental xu d \6с Бо тај movie machines, леса arti slide rule, pipes, exploding novelli wings, master keys. brass knuckles, all wave radio, college diplomas and marriage licemas. dance & gold writing тосоо ILLUSTRATIONS, 5000 NOVELTIES ictus iUas Bigger and better thon ever - things you never thought existed ` articles you have always wanted!

Page 167

FOR MEN ONLY. is now on sale at all newsstands If you hurry, you may still be able to buy а copy. STATEMENT OF THE OWNERSHIP, MANAGEMENT, CIRCU- LATION. ETC.. REQUIRED BY THE ACTS OF CONGRESS OF AUGUST 24, 1912, AND MARCH 3, 1933 Of MODERN MECHANIX, published monthly at Louisville, Ken- tucky, for October Ist, 1937. State of Connecticut 25 County of Fairfleld i Before me, a Notary Public in and for the State and county afore- said, personally appeared Conway Bolstad, who having been duly sworn according to law, deposes and says that he is the Business Man- | ager of the MODERN MECHANIX and that the following is, to the best of his knowledge and belief, a true statement of the ownership, management (and if a daily paper, the circulatlon), etc., of the eforesaid publication for the date shown tn the above caption, required by the Act of August 24, 1912, as amended by the Act of March 3, 1933, embodied in sectlon 587, Postal Laws and Regulations, printed on the reverse of this form, to wit: 1. That the names and addresses of the publisher, editor, manag- ing editor, and business managers are: Publisher, Modern Mechanix Publishing Company, Greenwich, Connecticut; Editor, Robert Hertz- berg, Jackson Heights, Long Island, N. Y.; Managing Editor, Ralph Daigh, New York, N. Y.; Business Manager, Conway Bolstad, Old Greenwich, Connecticut. 2, That the owner 1s: (If owned by a corporation, its name and address must be stated and also immediately thereunder the names and addresses of stockholders owning or holding one per cent or More of total amount of stock. If not owned by a corporation, the names and addresses of the individual owners must be given. owned by a firm, company, or other unincorporated concern, its name and address, as well as those of each individual member, must be given.) Modern Mechanlx Publishing Company, Greenwlch, Conn.; Fawcett Publications, Inc., Greenwich, Conn.; W. H. Fawcett, Green- wich, Conn. ; Roger Fawcett, New York, N. Ү.; W. H. Fawcett, Jr., Greenwich, Conn.; Marion F. Bagg, Tulsa, Okla.; Gordon Fuwcett, Hollywood, Calif.: Roscoe Kent Fawcett, Greenwich, Conn.; Frances M. Fawcett, Greenwich, Conn.; Margaret Connor, Seatlle, Wash.; Eva Adams, Seattle, Wask.; Clarence Fawcett, Portland, Ore.; Gloria Fawcett Trust, L»7uila, Calif.; Virginia Loe Fawcett Trust, LaJolla, Callf.; John Fawcett Trust, New York, N. Y.; Nellie O’Brien Trust, Waseca, Minn. 3. That the known bondholders, mortgagees, and other security holders owning or holding 1 per cent or more of total amount of bonds, mortgages, or other securlties are: (If there are none, so state.) None. £. That the two paragraphs next above, giving the names of the owners, stockholders, and. security holders, if any, contain not only the list of stockholders and security holders as they appear upon the books of the company but also, in cases where the stockholder or security holder appears upon the books of the company as trustee or in any other fiduciary relation, the name of the person or corpora- tion for whom such ігиѕісо is acting, is given; also that the said two paragraphs contain statements eml-racing affiant’s full Knowledge and belief as to the circumstances and conditions under which stockholders and securlty holders who do not appear upon the books of the company as trustees, hold stock and securilles in a capacity other than that of a bona fide owner; and this afflant has no reason to believe that anf other person, association, or corporation has any interest direct or indirect in the said stocks, bonds, or other securities than as so stated by him. р : 5. That the average number of copies of each issue of this publi- cation sold or distributed, through the mails or otherwise, to paid sub- seribers during the twelve months preceding the date shown abore is ао (This information is required from dally publications only.) CONWAY BOLSTAD, Business Manager. Sworn to and subscribed before me this 24th day of September, 1937, Helen М, Lano, Notary Public. My commission expires February 1, 1941 When Answering Advertisements Please Mention December Modern Mechanix Know Electricity as Experts Know It—and Get an Expert’s Pay? Recovery has begun! The months ahead are. charged with signif- cance and expectation. What will you do to get the jump on the other fellow? Thousands of men have used The Croft Library of Practical Electricity The Croft Library is a complete elertrical educator. It is founded on practlce—on 20 years of shirt-sleeve experlence—on work as It is actue ally done. It is jammed from cover to cover with the kind of harde 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 59,000 highly paid electrical workers and engineers. Croft tells you the things you need to know about motors, generators, armatures, come mutators, transformers, circuits, switchboards, distribution systems— electrical machinery of every type—wiring for tight and power—wirlt of finished buildings—underwriters’ and municipal requirements—il- lumination in Its every phase—the most Improved methods of lighting— Jamps 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. е 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 | се ——H'— (€ — P — rat! | McGRAW-HILL BOOK CO., 330 Үү. 42nd St., New York | 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 $18.50 15 paid. If not wanted, I will return the books postpaid. {To insure prompt shipment write plainly and fill in all lines.) Name Home Address | | | City and State | Position Name of Compárny-ocooc2lzoccccamszdcdeme mam MMx-12-37 | Cheaper HEAT - Without COAL New invention Fits Any Stove or Range 30 Days Free Trial Remarkable invention burns 96% air, 4% of a cheap variety of oll obtainable everywhere. Does away with coal, wood, ashes, dirt and drudgery. Clean, silent, quick, like gas heat. 3 times hotter than coal and cheaper, Temperatura “i controlled. No more getting up on blt- ter cold, wintry mornings. Many auto- matlo features. No gas or electricity needed, Safe as any ordinary kitchen range. Easy to install—no damage to stove—simply slts in firebox of any stove, range, heater or furnace. Costs just a few cents a day to operate. TRY 30 DAYS AT OUR RISK. Low introductory price and 30-day trial. Write for FREE CATALOG. AGENTS and spare time workers: Oll heat saves money this year; people buy to Save. Write for free burner offer that starts you in busi- ness for yourself, Act NOW! Listed as approved by Nat’! Board of Fire Underwriters. BRIGHAM OIL BURNER CO.- 2923-N, Clark Ave., St. Louis, Mo =] AIR CONDITIONING LEE and Refrigeration Trial Lesson A fast growing field of opportunity, Trained men are needed. Learn the easy C.T.C. way. AT HOME IN SPARE TIME AT LOW COST Write today for FREE TRIAL LESSON CHICAGO TECHNICAL COLLEGE R316 Tech. Bldg., 118 E. 26th St. Chicago, Illinolg If you can go away to college to learn Air Conditioning, Engineering, Architecture, Drafting, Electricity or Radio, send for FREE Blue Book. EARN $60 A WEEK! Writa for FREE Burnar of-| forand protected territo 167

Page 168

$9 ooo Less Motor Drive Terms as Low as А Back-Geared Screw- Cutting Precision Lathe No. 415-YA, 914" awing by 3’ bed Workshop Bench Lathe with Horizontal Motor Drive, 14 H.P. Reversing Motor, Switch and Adjustable Belt Tension Оошцфегвһаб........................... ($15.00 down, $6.00 a month for 18 months) The 9-inch Workshop Lathe is a Precision Lathe with Back Gears, large V-ways on lathe bed, a Precision Lead Screw for cutting screw threads, and is designed to handle the finest, most accurate jobs in manufacturing—in the tool room, in home workshops and auto- motive machine shops. Workmanship and materials are the same as in our larger, more expensive modele, representing the greatest value we have offered in 30 years of fine lathe manufacturing. $122 00 LATHES for the MACHINE SHOP, MAN _ FACTURING PLANT and TOOL ROOM Features include Twin Gear Reverse to lead screw, Ball Thrust Bearing on Spindle, Automatic Longitudinal Screw Feed to Car- riage, Precision Lead Screw for Cut- ting screw threads from 4 to 40 per inch, %-inch hole through spindle taking collets up to 14-inch capac- ity. Takes 38 attachments for mill- ing, grinding, draw-in Collet chuck work, and many other jobs. FIVE OTHER SIZES South Bend Precision Lathes are manufactured in 9", 11", 13”, 15" and 16" swing, in bed lengths from 3' to 12’, in both Motor Drive and Countersbaft Drive. Write ғов а ТНЕЅЕ ВООКЅ Latest and most authoritative In- struction on_lathe practice and operation. “How to Runa Lathe” : S me c т = — À з South Bend Lathe Works, 525 E. Madison St., South Bend, Ind., U.S.A. Please send me the following: O No. 33LB “How to Run а Lathe,” 25c О No. 15Ү 9" Workshop Catalog, Free Г] Easy Payment Purchase Plan Class of Рогі... оаа і 1 i 1 has 160 pages with over 300 illus- 1 trations showing every type of p werk done on a lathe. Over 1,500,000 copies already sold, U Priced at 25c each. New, Ontalor U No. 15-Y illustrates, deseribes, an | prices the 9-inch Workshop Lathe p 28 different drives and 4 bed " lengths. Copy sent free postpald. 168 Accept No Substitutes! Always Insist on the Advertised Brand!

Page 169

Simplifying Winter Starting [Continued from page 142] Excessive churning of the starter will rapidly depreciate the battery’s charge, often to the point where scarcely enough current remains to operate the ignition coil. In cases of this kind, the car can be started by an emergency measure. Dis- connect the “hot” lead to the storage battery and connect it by means of an ordinary piece of lamp cord to one side of a bell-ringing transformer secondary. Connect the other termi- nal of the transformer's secondary to the car's frame, Crank the car by hand and it will fire quickly. Let it run until the engine is thoroughly warmed up, and then reconnect the battery. Another spin of the hand crank will restart the car and it can then be driven off, А Аз frozen batteries are often caused by the cells being undercharged, the battery should be kept fully charged throughout the winter. Many attics will yield a storage battery charger that was put to rest with the advent of the family's first electric radio, This same charger can be used to maintain a full charge in the car battery by connecting it, with the correct polarity, to the frame of the car and to the insulated terminal on the generator cut-out, each night after putting the car away, À final precaution concerns the transmission grease. In every instance summer grease should be replaced with a light lubricant intended for winter use. Many motorists fail to realize that car stalling is often due to the "drag" or re- sistance of heavy oil on the driveshaft. This is harmful to the car and should be avoided by all means. How To Print Your Pictures [Continued from page 145] After the prints have “fixed” in the hypo for the prescribed 15 minutes, wash them in running water. The wash basin arrangement pictured on vage 105 of the November issue will serve nicely. Keep the prints well separated and let them wash for about thirty minutes. To dry, place between the leaves of a “blotter book," weight the book with a flat iron or one or two bricks, and put it away until morning. If glossy prints are preferred buy glossy paper instead of the semi-matte, and develop exactly as outlined. To dry them, however, a "ferrotype" plate will be needed. "These are made of brass, with one side heavily chromium plated and polished, and have no iron in them at all. To use the plate, wash the polished surface with ordinary soap, rinse off with hot water, and apply the wet prints face down. Roll them flat with a print roller and set them aside to dry. In a few hours they will pop off by themselves. The 10 by 14-inch size will be found most convenient for amateur use. The hypo can be saved for future use. The acetic acid solution is good for several dozen prints, and can also be saved, but it is a good idea to mix a fresh bath for every batch of prints. The developer cannot be saved for more than a few hours. These various chemicals are so cheap that it is foolish economy to try to stretch their life. Here are a few concise precautions to observe: In handling negatives, hold them by the edges and keep them clean and dry. Take out one sheet of paper at a time, and keep the rest in the black envelopes. Filter developer, short-stop bath and hypo before use. Wash all trays and other vessels in plenty of running water before and after use. ; Have the various solutions as near 70 degrees F. as possible. Don't hesitate to experiment! EL ES Many model builders are not aware of the fact that the G. H. Q. gas engine once sold for $35 each and the demand was so great that there was a waiting list of customers. Mass production methods and enthusiastic customer reception have enabled us to lower our price, postpaid, to $8.50 for a finished parts set and $12.50 for the completely assembled motor. ONE DAY SERVICE 6 "d .," Flies model a planes up to 10 foot wing» spread; also used for boats, etc. An engineering tri- umph accomplished Bfter years of research. No oil, gas or batterles included. A finished flywheel mounted on every assembled motor. FINISHED PARTS KIT $8.50 FINISHED ASSEMBLED MOTOR—with flywheel $12.50 - G.H.0. MODEL AIRPLANE CO. ~ | 854A East 149 St. New York, N. Y. 4 Port 2 Stroke Crcle— $$" Stroke— 1$" Bore— 300-12,000 R.P.M.— Weight, 12 oz. (Motor)— Turns 14" Prop. 8" Piteh— Bearing Surface. 35" x13," Crankshaft, у” Diam.— Rotation, Either Directlon POST PAID ave [DEAL ХМАЅ GIFTS" Л. Radio-Electrical EXPERIMENTS. 25-PIECE KIT! Genuine Commerclal Apparatus—Not Toys! Dozens Experiments—Wire up thlef-de« tector, extenslon phone, electric welder, radlo code set, electro-plating, arc- fur- nace, circult tester, rectifier, 110-volt motor, arc light 4,000-ft. range, secret service phone enerate sun tan health rays, make electric stove, etc. Contains 110-volt А.С. motor, microphone, trans» . former, polarized test receiver, arc carbons, elec- tro magnet, test compass, plating chemicals, cone denser, 110-volt Inductances, magnet, anodes, test socket, 110-volt power reducer, test cords, clips, etc. Our Kits used by leading schools! t 6 BOOKS Free with kit! Instruction manuals, Theory of унау тр ара —Send only . or complei 16 and booke (actual value over $10.) Or, sent C.O.D. Shíppe: 6 Books FRE same day order received, Sc stamp bringe Bargain Catalog. ELECTRICAL SALVAGE CO., Box 524-50, Lincoln, Nebr. enough to cover an End Tabla with a GLEAMING FINISH ! Home craftsmen—put life and sparkle in your master. Plecest Here Is a new finish that is guaranteed to do а perfect, fob. PROTECTS NEW SURFACES—and—BEAU- TIFIE- OLD SURFACES. Ideal for furniture, toys, models, Minlatures, woodwork, boats, floors, linoleum, and a hun- just brush it oncor wine it d prestol YOU HAVE А rus! on—or wipe on—and pres PERMANENTLY GLOSSY FINISH. Р Can be washed, cleaned, scrubbed, handled. Immune to salt water, alcohol, alkalies, most chemicals. Withstands heat, pressure, vibration. Add that “‘professional totuch'' to all your craft work or repairing. Send for this swell product JIFFO is not today, To keep away curlosity hounds and & polish, not sample colectors, please enclose 10€ for post- а wax, not 2 age and handling. lacquer, — Xt MAIL COUPON NOW! is a remark- TULIT m t m cu em oC vUa mama i wm able transpar- JIFFO PRODUCTS CO. ant liquid—a | 283 Third Ave., New York City Shoot me а can of Jiffo. ГЦ gamble а new develop- ment of syn- l thetic chem- istry. 1 dime (stamps or coin). When Answering Advertisements Please Mention December Modern Mechanix 169

Page 170

A focusing magnifier which is placed on the easel of a photo- graphic enlarger. It projects an enlarged image to the eye of the operator, enabling him to adjust machine fot exact focus. A heavy vehicle-type fire extinguisher with Special "shock absorber" construction to with- stand excessive vibration. It is fitted with specially built sturdy steel brackets in two styles for truck and bus use. A silent, automatic humidifier for home use. It has no moving parts and empties ten to twenty- four gallons of water into the air per day. A machine which automatically grades pota- toes according to size. A lightweight and compact microphone claimed to be 100 per cent directional. Case is of moulded bakelite. An improved, lightweight bridge or industrial floor unit. Its unique construction eliminates need for intermediate beams on spans from five to twenty feet. A bright ray fog light which is water proof and dust proof, and clamps securely to'the bumper of a car by means of a heavy-duty malleable cast iron bracket. A device which automatically opens garage doors when the cars headlights are turned on. Can be applied to doors now in use. May also be operated by a switch mounted on a post located at the side of the driveway, so that it may be reached by the driver with- out leaving the car. A synchronized range finder for use with practically all folding cameras in the popular 9 x 12 cm. size. 170 Now docs for Homes Shop ГА А canopy type lightingunit which provides com- pletely diffused, high intensity illumination. A road striping outfit which con- sists of a striping machine and gun, hand valve,. neces- sary hose and con- nections for all operating condi- tions. Aworkman’shat molded in a single piece crown, flared at the base to form a brim. It is non-rigid, and " being non-brittle, does not crack under the În- pact of blows. Various size brims are avail- able. A dial caliper is designed for the direct reading of a measurement by means of a dial and hand instead of the conventional vernier. À power sweeper designed for all types of sweeping jobs on large areas ordinarily cared for by a crew of men sweeping with hand brushes or brooms. The machine can be equipped with a sprinkling attachment when raising dust would be harmful. An erasing machine designed to save time, money and materials. Built for use on either 110 volts A.C. or D.C., the rotary eraser is said to leave no smudges or holes in the paper or cloth. A print protec- tor, designed to hold a working drawing, order card, chart or any paper handled in a plant, has a trans- parent front.Itmay be hung from or screwed to a ma- chine or wall. The holder ean be filed in a standard file or desk drawer. Large drawing can be folded so that the working por- tions face outward when in folder. A combination rose and key plate for use with sectional door trim Eraser for ink and typewriter, using rubberglass and fiberglass refills.

Page 171

COMPRESSED AIR FIRES BULLET > screener IN NEW TARGET The lower “barrel” of this highly accurate pistol is really an air pump. Air is pumped into a “com- pression chamber” where it ts held until the trigger mechanism releases it into the barrel to drive a lead pellet. Enough force can be“ pumped up" to pierce a tin can easily. Practice arm demonstrates HIGH COMPRESSION principle of modern auto engine HE greater the air pressure back of the air- To pellet, the further and harder it will shoot. The higher the compression in the cylinders of your motor car, the more power you get. It's as simple as that. And that's why automo- bile manufacturers are using high compression engines in even the lowest priced cars. These cars squeeze fmore power, more mileage, more get-away from every drop of gasoline. GIVES YOU A BETTER RUN FOR YOUR MONEY Look for this emblem om the base or globe of every Ethyl pump. It means best-grade gasoline. RINTE; RED USB HIGHLY COMPRESSED AIR gives speed and power to the lead pellet being driven through the rifled barrel of the Benjamin air pistol. HIGHLY COMPRESSED GAS mix- ture in the cylinders of your auto- mobile engine gives extra power, more mileage, and that added re- sponsiveness so important in emer- gencies. Only Ethyl permits you to get the full benefit of this compres- sion—lets your car dealer advance the spark for maximum performance. To get these advantages go to your car dealer and have him set the spark for maximum perform- ance and then use a fuel made for high compression! Stop at the “Ethyl” pump. There you get more anti-knock fluid (containing lead tetraethyl) thaa you get in the best regular-grade gasoline. By pre- venting harmful knock you make sure of 100% performance from your high compression engine. And remember—at these Ethyl pumps you get all-round quality that is double-tested— by the oil company and by the Ethyl laboratories. GETS FULL POWER FROM HIGH COMPRESSION

Page 172

Page 173

uble Page Spreads

Page 174

| Will Train You at Home— mail coupon for FREE Book Do you want to make more money? Radio offers you many opportunities for well-paying spare time and full time jobs. You don't have to give up your present job, leave home or spend a Jot of money to become a Radio Expert. ro: || Betabilinca Tora e man has directed “the home study training of more HERE'S PROOF THAT MY TRAINING PAYS Chief Operator | Broadcasting station " Я completed 2, ae Many Radio Experts Make Radio Broades Station $30, $50, $75 a Week Radio broadcasting stations employ engineers, operators, sta- tion managers and | pay up to $5,000 a узаг, Spare time Radio set servicing pays as much as $200 to $500 a year—full time jobs with Radio jobbers, manufacturers and dealers as much as $30, $30, $75 a week, Many Radio Experts operate their own full time or part time Radio sales and service businesses. Radio manufacturers and jobbers employ testers, inspectors, foremen, engineers, servicemen, paying up to $6,000 a year. Radio operators on shins get good pay, see the world besides, Automobile, police, aviation, commercial Radio, and loud Speaker systems are newer fields offering good opportunities now and for the future. Television promises to open many good jobs soon. Men I trained have good jobs in these branches of Radio. Read their letters in my 64-page book. Mail the coupon. There's a Real Future in Radio for Well-Trained Men Radio already gives good jobs to more than 300,000 people. And in 1936, Radio enjoyed one of its most prosperous years. More than $500,000,000 worth of sets, tubes and parts were sold—an increase of more than 60% over 1935. Over a million Auto Radios were sold, a hig increase over 1935. 24,000,000 homes now have one or more Radio sets, and more than 4,000,000 autos are Radio equipped. Every year millions of these sets ко out of date and are replaced with newer models. More millions need servicing, new tubes, repairs, etc. A few hundred $30, $50. $73 a week jobs have grown to thousands in 20 years. Aud Radio is still a new industry— growing fast! Many Make $5, $10, $15 a Week Extra in Spare Time While Learning Almost every neighborhood needs a good spare time service man. The day you enroll I start sending you Extra Money Job Sheets. They show you how to do Radio repair jobs, how to cash in quickly! Throughout your training I send you plans that made good spare time money—$200 to $500 a year —for hundreds of fellows. My training is famous as “the Course that pays for itself.” OLLIS F, HAY ato caper, Mich. son St. $10 а Week in Spare Time “My work has consisted of Radi servicing, with some Public "dress Systems ‘work—all in my spare time My earnings in Radio amount to $10 a week."—NWILLIAM 3 T05 Ridge Road, Hobart, Ind. Store he Stere chi Sto S ded MOL KM AT ан Towe my success stoy ur COS Howard . С. ARAM Ga. and $200 to $300 a Month " in Own Business “For the last 18 months I hi im business for myself, making between $200 and $300 a month, Т have N.R. ш ерйп. my start in this field.” — L ЕНОЕН 22 Ave., Goose Creek, ease Б, "Texas. eman for Two Sunt г on work for two a am han- эю RENTA EL АМ a Sr EL Бе Уш, та. THE TESTED WAY TO 6 Accept No Substitutes! Always Insist on the Advertised Brand! * SET SERVICING. many $5, $10, $15 a week extra while lea time servicing pays as much as $30, $50, Spare time set servicing pays ing. Full a week. Pe ween oe v BROADCAST- ING STATIONS, Employ manager engineers, оре aj т » ators, installation I Give You Practical Experience and maintenance men for fascinatii jobs and pay up to $5,000 a ye Course is not all book training. I send vou special Radio Equipment; show you how to conduct expcriments, build circuits illustrating important principles used in modern Radio receivers, broadcast stations and loud speaker installations. I show you how to build testing apparatus for use in spare time work from this equipment. This 50-50 method of training makes learning at home interesting, fascinating, practical. You Get a Money-Back Agreement 1 am sure I can train you successfully. I agree in writing to refund every peuny you pay if vou are not satisfied with my Lessons and Instruction Service when you finish. ГИ send you a copy of this agreement with my Free Book. Find Out What Radio Offers You Act Today. Mail the coupon now for “Rich Rewards in Radio." It’s free to any fellow over 16 years old. 11 prints out Radio's spare time and full time opportunities and those coming in Television; tells about my training in Radio and "Television; shows you letters from men I trained telling what they are doing and earning. Find cut what Radio cfers YOU! MATL THE COUPON in an envelope, or paste on a postcard —NOW! LOUD SPEAKER SYSTEMS. Building i Shana, servicing and operating public ad- x systems is another i field for men i fen trained in Radio. AUTOMOBILE RADIO. Another new Radio ficld—selling, in- stalling, servicing, One million or mor owners will install sets within the next year. J. E. SMITH, President, National Ra Institute, Dept. 7NH, Washington, D. С. J. E. SMITH, President, Dept. TNH National Radio Institute, Washington, D. C. Dear Mr. Smith; Without obligating me. send "Rich Rewards in Radic,” which points out the spare time and full time opportunities in Radio and explains your 50 method of training men at heme in spare time to become Radic Experts, (Please Write Plainly.) NAME .. ADDRESS BETTER P P STATE .. When Answering Advertisements Please Mention December Modern Mechanix 7

Page 175

A frank man to man talk about PATENTS-INVENTIONS - SELLING INVENTIONS HE world of invention moves on. About a hundred years ago people were saying, "There's nothing left to invent"—today we know that is one of the funniest things ever said. Just think what has happened in the last hundred years! Autos, radios, airplanes, and thousands of useful, practical devices for home, shop and office have been invented and put on the market. Inventors are con- stantly making the world a better place to live in. Did you see a notice in the paper that an obscure worker, Hans Wach, has invented a simple device to utilize exhaust steam on steam boats. Already, the report states, the steam ship lines have saved more than $15,000 in fuel bills with his invention. Almost in the same breath the Dept. of Commerce announces that it will soon test out a new non- crashable aeroplane, which the average man can learn to fly in a day, which will travel at 110 miles an hour and sell at the price of a cheap automobile. An unknown Seattle man has invented a robot to go 5,000 feet under the sea and recover millions and Who Are Inventors? You'd be amazed at the men we con- tact in the course of a busy year. Most of them do not consider themselves 4 inventors at all. During their work “л leisure they get an idea, They work it out on paper. They get in touch with us about Protection. Did you know that a dentist invented the stock ticker, a school teacher the telephone, a farmer the typewriter, an artist the telegraph? Did you know that the crinkly hair pin—sold by millions now—eame about because a husband saw his wife twisting the old-fashioned straight hair pin to make it stay in place? Poor men who have no thought of invention now will be financially well-fixed in a few years because of a happy thought that the world could use to advantage. sell any the average man. trouble, or delay. Copyright 1937 Victor J. Evans & C RUSH COUPON TO WASHINGTON D.C. TO Can You Answer These Questions? Ask yourself these questions: How the Patent Laws protect me? What easy steps can I take, without cost, to put те myself in position to support my belief E that I am the first man to think 3 = of my invention? Is a Patent worth the a model? hare it Patented? Ts there tions promptly answered. safe, business-like way millions of dollars worth of gold lying at the bottom of the ocean since the days of the early Spaniards, Remember this: For every outstanding big inven- tion there are thousands of small, simple things for use in the home, the office, the factory, on the farm, on every sort of travel conveyance. Little articles like you find on the counters of a 10-cent тоге hardware store, drug store, toy and novelty shop. Many Little Ideas Have Big Commercial Possibilities A person finds something he's using doesn’t work right, or it's clumsy, or costs too much. Не gets a happy thought. He improves the old Article. That's contribution to human progress. That's the way that many, many men have reached the gold of financial comfort, independence and even wealth. Most of the things millions of us use didn't come from the brains of engineers and physicists. They came from the mind and maybe the crude home work bench of Mr. Average Man, busily engaged in earning his bread and butter at whatever chance or circumstance has given him to do. The “little” man's opportunity as an inventor was never greater than it is today. Our Business Is To Help You. Write Us Today Гог more than thirty-six years, this firm has been helping men with an inventive turn of mind. We maintain a large staff of trained, experienced — specialists—Registered Patent Attorneys, Draftsmen, and Searchers to help our clients secure all the protection to which they are entitled. Fees are reasonable. De- ferred payments frequently arranged. Ques- Write us frankly cost? Do I need Should I try to invention before I with absolute assurance that what you say will = Fgh to secure financial help? If be treated with strictest secrecy, But FIRST, =: d.e I do apply for a Saet send for the FREE BOOKS shown on the op- how shall I reach people who сап market my invention? Сар I protect and tures and suggestions. They tell you things sell an improvement on some invention that about Patents, Inventions and Selling Inven- has already been patented? These are but a tions that we have learned in our long Tew of the questions whieh usually confront experienee. They may save you time, expense, You need the answers] EVEN LATER DISAPPOINTMENT. Simply YOU CAN HAVE THEM, without cost, fill in the coupon. No charge, no obligation. posite page. They are filled with facts, pic- Write us today. 8 Accept No Substitutes! Always Insist on the Advertised Brand! 145 Mechanical Move- ments Like These Besides many other features and facts there are 115 differ- ent mechanical movements and principles in the big, 48-page Book below. Maybe there is just the idea you need to solve some mechanical problem. Use the coupon or write us a card or letter. FREE BOOKS with 68 PAGES of Facts and Pictures! VICTOR VANS & бо. REGISTERED PATENT ATTORNEYS MAIN OFFICE: 220-P, VICTOR BUILDING, WASHINGTON, D. C. Other Offices: 2010-В, Singer Bldg., New York 2135-8, Monadnock Bldg., Chicago 1010-B, Hobart Bldg., San Francisco 305-B, Garfield Bldg., Los Angeles i NEW BOOK About Selling INVENTIONS So far as we know, the facts in this booklet have never before been pub- lished by any Patent At- torney. You are given very definite suggestions Send me FREE copies of your books, "Patent Protection’? and “When and Ilow 10 Sell an Invention." (Note; Ваше books supplied by ёпу of branch offices listed above.) NAME —————Mr Street and NO, sessseeseeseevececnenneeesneneneveeeeeesseeen eens City or Tow State ә When Answering Advertisements Please Mention December Modern Mechanix

Page 176

How To Determine The Patentability Of Your Invention Before you spend money in making a model, or spend weeks in its design, we advise you first to have a preliminary search made through U. S. Patents in the U. S. Patent Office to see if there are inventions like yours already on record ; and, if so, let us give you our opinion as to the patent- ability of what you have. We employ experienced searchers to perform this service for you. From the reports of our searchers we can quickly form our opinion as to whether vour invention is confronted with ob- stacles in the form of already granted patents. First get our FREE BOOK and read the chapter on "How Can I Know Whether My Idea Is Patentable ?" How We Serve The Inventor 7; 5° ov every state in the Union. Our organization is a large and efficient опе. Our practice is con- fined entirely to Patents, Trade-Marks, and Copyrights. We have had years of experience in Patent Matters. When you place your in- vention in our hands, we are in position to proceed at once to secure protection for you. Our fees are reasonable, and, if you desire, we can arrange convenient terms of payment. CLARENCE A.OBRIEN & HYMAN BERMAN 3177 ADAMS BUILDING, WASHINGTON, D. C. Registered Patent Attorneys before U. S. Patent Office Help is the Patent Attorney? Vour invention may provide your life's great- est opportunity. If it is to hring income to you it sheuld be legally yours. Upon your patent attor- ney’s skill rests how completely your patent covers all the protectable points in your invention, The inventor may actually lose money on his invention by overlooking a single claimable point that a skilled patent attorney would not miss, What The Inventor M u S t K n о Ww nde the inventor must follow certain definite steps that precedent has established as the quickest way to reach his goal. Our FREE BOOK, "Patent Guide for the Inventor," gives a concrete, logical, and thorough resume for the inventor to follow. It takes him, through 48 pages, from the crude first model to the finished commercial product. It shows the inventor how to avoid mistakes, how to shorten the road in getting his invention ready for market; it also points out how to save money and avoid the errors of inexperience in applying for patent. Getting our FREE BOOK should be the first step in definitely declaring yourself an inventor. After you get this illustrated, clearly worded guide of care- fully compiled patent knowledge you will know how to pro- ceed without expensive mistakes and discouraging setbacks from 'wrong-track" methods. 12 Accept No Substitutest Always Insist on the Advertised Brand! FREE RECORD OF INVENTION FORM Ths FREE Record of In- vention Form enables you to make in con- venient form a sketch of your invention and have it wit- messed in a manner of value Keen competition in every form of in- dustry has put manufacturers feverishly at work trying to speed up output, reduce overhead, save on materials, outsell trade opponents. The inventor is the key-man їп making advancement possible to any business. Upon the inventor rests the success of many enterprises. This does not mean that you must have something gigantic to win commercial success. A new way to open a door or button up a shirt may be the very thing hundreds of manufacturers are looking for. If you have something novel —if it is practical to manufacture— , no matter whether it be an improved Ё rattle for a child or a whistle for a mechanical automobilc. there is likely a wait- ing market. to you should the occasion for evidence arise. MAIL TIE COUPON TODAY and obtain our FREE BOOK and Record of Invention Form. Importance Of Immediate Action In making application for pat- entitis important to be first. TEAR OFF Even if your application is de- AND layed by a few days you may MAIL CLARENCE A. O'BRIEN & HYMAN BERMAN 4 3177 Adams Building WASHINGTON, D. C. Ф Registered Patent Attorneys be placed at a disadvantage. NOW! a torc U. S. Patent Offico 1 Please send me at once your Big Eres 45. J hissing Cue elap ed Di SG c C SS This request does not obligate me. tween Elisha Gray'sapplication for his telephone patent and the application. of Alexander Graham Bell probably cost Gray the rights to the tele- phone. Fe a (Please write or nrin£ plainly) When Answering Advertisements Please Mention December Modern Mechanix 13

Page 177

20 GET RIGHT IN FOLKS,WE'LL HAVE YOU HOME IN NO TIME. 1DON'T KNOW WHAT WE WOULD HAVE DONE IF YOU HADN'T COME ALONG . ee WE'RE NEARLY FROZEN THEY TOLD ME IT WAS JUSTAS GOOD..BUT IT MUSTHAVE BOILED AWAY f DURING THE WARM ‘SPELL LAST WEEK. £ | "NEXT TIME, NEIGHBOR, GET THE GUARANTEED. ANTI-FREEZE . . . READ THAT. ..THERE'S NOTH- ING ELSE LIKE IT!” TRADE- ANTI-FREEZE IS Accept No Substitutes! Always Insist on the Advertised Brand! өңе all the brands available to U. S. motorists, there's no other anti-freeze like “Eveready” "Prestone." This anti-freeze is guaranteed, insures you against FREEZE- UP, BOIL-AWAY and RUST-CLOGGING, the three winter purse-snatchers that cost American motorists millions of dollars every year. € But when you gamble on anti-freeze you risk more than money...you take chances with your family’s health and safety, hazard all-winter comfort, wreck your peace-of-mind. € Every year millions more decide on safety, demand “Eveready” "Prestone" anti- freeze. So perhaps you should get yours early... Today, for example. Dors NOT BOIL Off ay, PREVENTS RUST A GALLON Buy "Prestone" anti-freeze from dealers who are prop- erly equipped to service your car for winter driving. RESTONE MARKS GUARANTEED IN Uniting When Answering Advertisements Please Mention December Modern Mechanix

Page 178

Few thrills can equal those provided by a powered iceplane like this one built by Milton W. Graves, of Adams, Mass. The rudder and elevator controls operate like those of an airplane. ITH long winter evenings at hand, the time is ripe for dusting off the workshop bench and tools and starting work on projects that will bring hours of enjoyment and recreation next Spring. Suitable plans and articles to meet the fancy of every type of home-craftsman can be found in each issue of MM or in the books—"How To Build It,” “How To Build 20 Boats," or "How To Build Trailers," copies of which are available at 50c each from your local news dealer or direct from MM at Greenwich, Conn. жек Milton W. Graves, of Adams, Mass., was awarded the first prize of $5 in this month's Workbench contest, for his photo and letter describing a powered iceplane. His letter reads: Dear Editor: lam enclosing a photograph of my iceplane, which is powered by a used motorcycle engine. How do you - like it? The propeller is driven directly from the motor, which is mounted to a wooden frame fuselage covered with dope-treated airplane cloth, The elevators are controlled with a joy stick while the rudder is manipu- lated by placing my feet on a rudder bar. The plane levels off and rides on the two front run- ners, which are six feet apart, when a speed of about 20 miles an hour is attained. I received many ideas for my plane from past issues of MM. Milton W, Graves. We can wel imagine that Graves’ iceplane provides thrills that are akin to real flying. If YOU want to have some real fun, fellows, follow 28 Graves’ example and build a powered iceplane. RHR A $3 award was sent to Winston B. Mackley in far away New Zealand for his photo and details of a record- breaking model plane. The letter states: Dear Editor: Enclosed is a photo of my microfilm covered hydroplane. It rises off the water and recently set a New Zealand record for models of its type by remain- ing aloft for 4 minutes, 46 4/5 seconds. I shail be glad to correspond with American model builders. My address is 8 Ascot Drive, Remuera, S. E. 2, Auckland, New Zealand. Winston B. Mackley. Microfilm, being eight times lighter than tissue paper, is being used on more models every day. We would like to know if MM modelers would like to see an article on how to make and use microfilm. Send in your suggestions for articles at any time, as they are always welcome. ok Few projects surpass midget racers in popu- larity with MM readers. A photo and letter from Abner A. Beyer, of East Greenville, Pa, de- scribing his racer, was awarded a $3 prize. He Says: Dear Editor: Enclosed you will find a snapshot ot the midget racer I built. It is 51% feet long, has a 45-inch wheel- base, and a 30-inch tread. Power is supplied by a 3/4-horsepower engine. Fitted with tiny pontoons to permit takeoffs from water, this microfilm-covered model set a New Zealand flight record of 4 minutes, 46 4/5 seconds, reports builder Winston B, Mackley. Modern Mechanix The tiny car has three speeds forward and one re- verse. Its construction features a steel frame sup- ported on four springs, the front ones being 18 inches long and the rear, 22 inches.. (The driver is four years old.) Abner A. Beyer. We think most readers will agree with us when we say that Beyer's midget racer is an unusually fine one. жж Ап award of $3 was sent to Nicholas Stark, of New York, ЇЧ. Y., for an interesting project photo and letter. Stark writes: Dear Editor: : I am enclosing a photo of my powered scooter, des signed and constructed by myself. It is 40 inches long and driven by a 34-horsepower washing machine motor, The scooter is started by à good push and a speed of 25 m.p.h. is obtained. Low gas consumption makes the operating cost very reasonable. Nicholas Stark. We'll bet that reader Stark is much envied by the neighborhood boys when he rolls up with his powered scooter. It cer- tainly is a useful and pleasure-giving project. deb This model locomotive, built Бу Bartlett Sissons, is а perfect replica of its Canadian National Railways prototype. Dear Editor: I enclose a photo of a Canadian National locomotive model that I recently constructed, This model is run by a motor situated in the firebox and geared to the driving wheels. Your article on Midget Mike helped me very much in constructing this and other locomotive models. Bartlett Sissons. Sissons’ model locomo- tive is a good looking job. Model railroaders who want to build a fascinating little locomotive should secure a copy of the latest “How To Build It” book and read the article on building Midget Mike. Nicholas Stark with his home-built power scooter. эз» ` Model locomotive fans will be interested in a letter and photo from Bart- lett Sissons, of Alberta, Canada, who was awarded a $3 prize. The letter reads: Midget racer fans will be quick to acknowledge that this speedster, built by Abner A. Beyer, is one of the finest ever shown in MM pages. The "driver" is four years old. December, 1937 Unless builders of model airplanes powered by miniature gasoline engines unite in their efforts to combat threatening legislation, they may find themselves in the same predicament as the home- built aircraft fans—banned from flying their creations. Several states have already banned gas-powered models, one state passing a ridicu- lous law requiring the builder to hold a real air- plane pilot's license before he can launch his model! We strongly urge every airplane model builder to protest laws that would ban the flying of gas- powered models and request that you file your letter of protest with the editors of MM who will co-operate with aviation editors and organizations preparing to wage "war" on the proponents of legislation that would be detrimental to the hobby of flying gas-powered models. Жжжж Although this year's boating season is well over, we know that many MM boat fans will find a [Continued on page 31] 29

Page 179

Coil spring rear suspension is an ex- clusive Buick feature for 1938. Com- bined with airplane type shock absorbers, this provides greatly improved riding and steering qualities. -Phcto below shows spring and shock absorber hook- up on right rear wheel of Buick chassis. Size and thickness of spring may be judged by «comparison with tire. Driving effort is greatly reduced, and control over the car is increased, by the new ''Tiptoe-Matic' clutch intro- duced in the 1938 Chevrolets. The makers claim that 25% less effort is requited to operate this clutch than in the 1937 model. The mechanism needs no lubrication throughout the life of the car. А new type of hand brake is also a feature. This has a hinged top, and is easy and positive in operation. Chevrolet remains a six-cylinder car. the valve-in-head engine being brought up-to-date with many small improve- ments. In the Master series fully-en- closed knee-action is also retained. Unusually roomy interiors give the new Chevrolets increased comfort and utility. Photo at left shows the un- usually capacious trunk, which also contains the spare tire. = CHEVROLET This is the master deluxe coach of the Chevrolet 1938 line. The new styling is especially evident in radiator and hood. No-draft ventilation, all- steel bodies and safety glass continue as standard features. ч Above: Buick’s self-shifting transmission has the control arm оп the steering post under the wheel at the right. Photo shows the completely cleared driver's compart- ment. Hand brake is under cowl at extreme left. Left photo: The Buick hood lifts from the molding line, providing for quick and convenient "light" service. Hood side panels are stationary, lending strength to the entire front end sheet metal assembly. Radiator grilles are die-cast. A cutaway view of Hudson’s powerful duo-automatic hydraulic braking system with the “double safety” feature of an emergency mechanical brake linkage operating from the same foot pedal. This feature enables the driver to re- tain control over the car even after the hydraulic system has been dis- connected, by continuing to press on the pedal until the emergency rotary-equalized mechanical brakes take hold. The complete Hudson line consists of an eight-cylinder car made on both 129 and 122- inch wheelbases, a six on 122-inch wheelbase, and the Hudson Ter- raplane on a 117-inch wheelbase. Above—-The interior of the 1938 Pontiac. The safety-shift remote control gear lever is shown directly below the deluxe type steering wheel. In- strument panel with accessory electric clock can be seen. Right—The Silver Streak radiator and hood grille of the new Pontiac. No other style motif has been so characteristic of Pontiac since its introduction four years ago. Note the parking lights integral with the headlamps. The 1938 Hudson auto- matic shift includes an automatic circuit breaker switch which causes gear shifting to take place at the proper instant when the clutch is disengaged. Left—1ts steering control lever located conveniently near the rim of the steering wheel, affording finger tip control, Nash's new vacuum gear-shifting system is shown here in diagrammatic detail. Above—The instrument panel of the new Nash. The ait conditioning unit is shown just below the gear shift lever. This device supplies an abundance of warmed, conditioned air for winter driving. 37

Page 180

Looking at the 1938 Studebaker (left) from the front, one sees streamlined headlamps íaired into the broad steel fenders of the various models. The frames, chassis and bodies are entirely new. 'The bodies are approximately six inches wider than Jast year's models, providing 552 inches front seat and 471% inches rear seat room, Frames are lighter and feature increased overall torsional rigidity. The vacuum gear shift featured by 1938 Studebaker models utilizes the engine mani- fold vacuum to actuate the transmission gear - changes. A small shift lever (above). five inches long, extends from dashboard, leav- ing the floor free for passengers’ feet. Body lines of the 1938 Oldsmobiles are lower and cleaner, as shown at left. Bullet-type headlamps are demountable for economy’s sake in case of fender damage. All models are available with safety transmission, requiring use of clutch only when starting and stopping. 'OLDSMOBILE _ Oldsmobile models feature a battery housed alongside the engine under car hood (be- low). A duct carries cooling air through ae Bom c battery container, maintaining low tempera- ture in warm weather. II ve a De Soto's distinctive new “face” i (above) features a radiator grille $ made of horizontal die-cast 2 chromium bars. A new frame, e wider and deeper than before; bigger, more powerful hydraulic brakes and a new rubber-insu- lated steering set-up that isolates road shock from the wheel are the highlight features of the many mechanical improvements in the 1938 models. Successor to the Austin is the new American Bantam, selling at prices from $75 to $125 below any other car in the low-price field. Shown at right is the 1938 Bantam "60" coupe, powered by a 4-cylinder, 20 h. p. motor suspended on live rubber. Performance claims in- clude speeds of 60 m. p. h., 60 miles to the gallon of gas and an operating cost of J4-cent per mile. In addition to the coupe, the manufacturers announce a complete series of "60" models. The new Hupmobile series includes two models, a six and eight. powered by an L-head engine. Both models provide greater body width and length. A distinctive radiator grille design gives both models a dynamic head-on appearance. Radiator decoration serves as handle to permit access to motor. Headlights are built into the hood. Below—The new Willys Sedan for 1938 fea- tures a patented all-steel body and top, 178- inch overall length, safety type duo-servo brakes, improved steering and safety glass. The power plant is a Willys-built 4-cylinder engine providing economical operation up to 35 miles to the gallon of gas. Two models. a 5-passenger sedan and 3-passenger coupe. are available in a wide range of colors. WILLYS Below—All four models of the 1938 Packard in- corporate scores of new details. One novel fea- ture is the expulsion of engine heat through lou- vres located under the front fender skirts. The outstanding feature of the new “Junior” series is a revolutionary type of rear spring suspension. PACKARp а a

Page 181

» $ URSTING bombs failed to stop scores of German soldiers charging across the scarred battlefield under cover of night. The ground was rent by machine-gun bullets. Soldiers dropped hopelessly in barbwire en- tanglements. It was the World War all over again for many American Legion men and ex-German soldiers acting as extras during the filming of The Road Back. Every exploding shell and spattering of machine gun fire brought back memories of war's deadliness. But this was a movie war—nobody was being killed! Hollywood's explosive experts, through years of experience, have developed tricks that make acting in a movie war safer than cross- ing a busy highway. The script called for a night scene in the 42 LMIN A swinging boom (above) enables the cameraman to secure an action “shot” of soldiers marching from a trench. Left——Even movie “wars are hell" agree actors John King and “Slim” Summerville, warming their hands between scenes of the photoplay “The Road Back.” trenches in November, 1918, shortly before the Armistice was signed. It was bitter cold in France then. Universal Studio’s special effects department had little difficulty obtain- ing this impression, as the spring nights, when the battle sequences were shot, were extremely cold for California. The air was frosty and smudge pots blazed in orange groves nearby. But there was no snow such as blew over the Western Front in Novem- ber, 1918. To accomplish this desired effect studio workmen simply sprayed white paint over the ground. Several acres on the studio’s back lot was marked off for the battlefield. Official U. S. Signal Corps photos were scanned in order to get authentic detail into the battlefield set. A huge sky drop was built in the background, across the width of the battlefield. The sky drop consisted of a wooden scaffolding, some forty feet high, from which a great canvas curtain was hung. Painters were busy for several days spraying on “clouds.” This gave MOVIE WAR by Earl Theisen No expense or detail is spared to make . battle scenes realistic. the effect that the war ground’s horizon was several miles away. Twelve pieces of digging equipment—tractors, scrapers, and steam shovels, were required to dig trenches, grade the battlefield and to give it that shot-to-pieces appearance. Each day, after the night war episodes were shot, workmen would dig up the ground and sprinkle it with water to make the mire deep for the coming night. Realism of the first order. Real war is costly. So is a movie war! Thou- sands of rounds of blank ammunition for the 8 mm Mauser rifles were fired. One thousand pounds of black powder, five hundred pounds of dynamite, and 2,000 detonating caps went up in smoke for the combat scenes. Four hun- dred parachute-flares and seven hundred night flares were consumed during night film warfare. Workers prepare a shell-blasted farmhouse (center right) which will collapse in a later scene, while explosive experts (right) prepare a smoke bomb to provide thrilling action for the same scene. Few persons could tell whether this is a real or staged war scene, so real- istic does it ap- pear to the camera. 623

Page 182

It requires a combination of practical science and infinite patience to record a movie war. In the photo above, a sound man is shown at his control board. The horn is part of a loud- speaker system used by directors to address the movie army before it goes into "battle." Right — Spraying on a "sky" backdrop. Over a hundred gallons of liquid smoke, the preparation, ingredients and manufactur- ing processes of which are a carefully guarded military secret, were employed in the battle scenes. Navy planes use this liquid smoke to hide ships during maneuvers. Two "inventions" were worked out in the battle sequences. Ground oyster shells were found to give a better photographic repro- duction of dust, in shell-explosions, than dust itself. And by balancing the charcoal con- tent in black-powder bombs, greater photo- graphic value was given to explosions. Months of research must go into a war film before the cameras begin to roll. Hun- dreds of historic photos must be studied by the technical department. The wardrobe de- partment must correctly tailor the exact type of uniform worn by a certain regiment at a certain time. The studio arsenal must be sure to supply the correct rifle model. More care must be taken for carefully depicting recent wars than those of a century ago, as many veterans are film fans. Ralph Morgan, head of Universal's special effects department, who has worked on many war films, including The Big Parade, tells how one of the war illusions is achieved: "To get the effect of a shell striking the 44 ground and exploding we first dig the shell hole. The shell crater is dug in hard earth. The earth on the sides of the hole is tightly packed. Next the explosives man plants his powder charge in the center of the crater in such a way that it will blow straight upward. Then into the shell hole is sifted a mixture of earth and cork until it is even with the rest of the terrain. “A wire connects this prepared hole with the head explosive expert's control board. These shell holes are often marked by an odd clod of dirt, an old gun carriage wheel or a fake stump. Sometimes the danger spot is dabbed with a bit of paint that will not show in the film. The players, who have previously been coached by the director and his assistants, will avoid passing directly over these shell explosives. А shower of soft earth and ground cork will be the only dis- comfort actors who pass near these shell hole explosions will suffer." When you see a performer being blown skyward by an explosion you can be certain its a dummy. The dummy is usually made from rubber. Often an actual life cast of the actor the dummy is supposed to represent is made from rubber. This type dummy is more realistic than those formerly Modern Mechanix SHELL CRATER LOOSE MIXTURE OF EARTH AND CORK WIRE TO CONTROL The method used to prepare ground to get the effect of a shell striking and exploding, leaving a gaping shell crater, is sketched above. The crater is dug in hard earth, the sides the hole being tightly packed. Next, a measured powder charge is planted in the crater and covered with a loose mixture of earth and cork. А wire connects the powder charge to the explosive expert's control board located directly behind the scenes. used, which were stuffed with sawdust. The effects of bullets striking are obtained by two different methods. The usual system is to. fire away with the rifle ог machine- gun at the top of an entrenchment or building while the camera is safely located at one side filming the hits. Special care must be taken that bullets do not ricochet. This stunt is used when actors are not in the scene. To get the effect of bullets striking near players in trenches, tiny powder charges are embedded in the dust. These explosives have about the same power as toy torpedoes youngsters throw on the Fourth of July. In fact some explosives men have used torpedoes for this effect. A thin wire is attached to each charge and to a control board. As a man presses the control board buttons the small explosives go off, giving the effect of December, 1937 In filming “The Road Back,” the script called for snow flurries such as blew over the Western Front on Armistice Day, 1918, so studio workers sprayed white paint over the ground and trenches to create the proper background effect. a bullet biting the dust. The action of ma- chine-gun bullets striking can be had by firing a series of these minute explosives in a row, all within a few seconds. А new trick was used in The Road Back to get the realization of a French bullet crash- ing a mirror in front of "Slim" Summerville, [Continued on page 122] 45

Page 183

The speed of an iceboat de- pends to a large extent upon its construction. Hollow oval- shaped or streamlined masts and tear-drop runner planks should be incorporated in the design of a speed craft. AILING four times faster than the wind is a remarkable phenomenon alien to every other wind-driven vehicle but iceboats. Early craft, that only doubled the velocity of the wind, established the time-honored question, “Why do icecraft outpace the wind?” Improvements based on scientific develop- ment increased the speed ratio to 3 to 1. Today, ultra-modern ice-fliers achieve the The cockpits of modern ice- boats are designed not only for speed but for comfort as well. The two-place ice- boat shown below possesses both of these vital features. 4 to 1 ratio with greater frequency than the question is answered. Unless wind and ice conditions are favora- ble, relatively high speeds on ice are not ob- tainable. On smooth ice, a 10-mile breeze will propel a light-weather craft 40-miles an hour. Let's see what causes this phenomenon. То avoid complicated problems in physics and mathematics, a simple factor in aeronau- ties will illustrate the forces that contribute to iceboat speed. The wing of an airplane appropriately compares to sails. The curved top surface of an airplane wing has the sole purpose of creating suction, or lifting power, to hold the ship aloft. The greater the curva- ture, the greater the lifting power, while flying. It may be surprising to know that two-thirds of the total lift of the wings comes from top-surface suction and only one-third from the pressure brought to bear against the tilted bottom surface by flying speed. Similar factors are manifest in iceboat sailing. As the wind strikes the sail, it bellies. The curvature resulting on the lee side cor- responds to that of the airplane wing’s upper side. An efficient non-porous sail protects a vacuum behind it, while the wind is blow- ing. The presence of the vacuum can be de- termined by holding a match close behind the Modern Mechanix Itehoats Quadruple The СОЕ lll OF LIFT DIRECTION SPEED PRESSURE =i¢73 OF LIFT The iceboat sail compares with the lifting surface of an airplane wing, as shown in the above detail. Like the airplane top wing surface, two-thirds of the lift or pull on the sail is developed on the bellied side. sail, even while the craft is standing still, with sail filled. For lack of air, the match will go out. Hold another match farther from _the sail, protected by the wind, and the flame will be drawn outward by the suction. While under way, the vacuum causes a terrific suction behind the sail with a pull greater than the wind’s actual driving power. That pull provides two-thirds of the speed of average craft and three-fourths of that of racers. All this is predicated on the fastest point of sailing, which is 150 degrees ог 1315 points off the wind. Beam winds would seem to cause or create lateral suction or “sidepull.” But resistance of the runners prevents lee- way and directs the pull forward. Because December, 1937 Wind's Speed! the vacuum is greatest in quartering winds, sailing down-wind limits momentum to the wind’s speed. Speed consistency is impos- sible in puffy winds; rough ice and heavy snow are also speed deterrents. Another explanation is that an iceboat is like a wedge between the resistance of the runners and the lateral pressure of the wind. Between these opposing forces, the craft escapes the pressure by seeking the line of least resistance, which is forward. Because ice resistance is negligible, the craft, like a bar of soap wedged in one’s wet hand, shoots ahead with incredible speed. Again, an iceboat creates its own wind as it moves along. Its momentum sends a rush of air back to the sails to enhance driving power. Puffy winds, especially, furnish an example of this. As the craft gets under way, [Continued on page 120] 49

Page 184

Elevated skyward, the boom of this huge dragline looks like an oil derrick. In operation, the boom enables the dragline bucket to go into action at any point within the boom's radius. 52 Made possible only through the use of gigantic draglines, the All-American Canal (above) cuts through the desert for 80 miles and will be one of California's major watercourses when completed in 1939. The canal bed is over 200 feet wide and will carry water from Colorado River to Imperial Valley. Note how figure of man in photo is dwarfed by canal's width. HEREVER dirt has to be moved in huge quantities, there you'll find the drag- line man at the throttle of his snorting, puffing machine. He well earns his ten to fifteen dollars a day, for few workmen put out as much actual mechanical labor as he. Lately, engineers have given him a new tool—a gigantic dragline so huge it makes the kind you see digging foundations for a skyscraper look like toys. So far only eight of these monsters have been built, and it is safe to say there aren't more than a couple of dozen men in the whole world who have sat at the throttle of one of them. In the Iowa coal fields, one of the great- granddaddies of all steam shovels is uncover- ing a four-foot vein of coal, forty-eight feet below the surface. It reaches down like a monstrous ostrich, gulps off a fifty-ton bite, lifts it high as a seven-story building, and dumps it out of the way. Each bucketful would fill a good sized room. Two more are gouging the All-American Canal through sand hills of the Arizona desert. Several are repairing the ravaged Mississippi levees, and the biggest one in the world is in a Brazilian Modern Mechanix y | Maxwell В. Grant Withasingle scoop, man-made monstersequalthe work of hundreds of strong теп. : cement quarry. Its boom is slightly more than half a block long! Even if you have the half-million dollars to buy one of these big draglines, the chances are you won't want to buy it outright. There aren't many jobs big enough to keep this voracious machine busy long. Even the government usually rents one, for interest alone on the investment amounts to more than eighty dollars daily. Then, it costs a lot to get it on the job. When one of the big machines was shipped out to the All-Ameri- can Canal job in. California, it took eighteen freight cars to hold its dismantled parts. One of the weirdest sights imaginable is to see one of these huge diggers actually walk. December, 1937 Picking up an auto is child's play for the bucket of a drag- line used to make the All-American Canal (circle). Top—The bucket “on the move.” Right—Control cabin of huge dragline. 53

Page 185

This queer looking machine picks up dragline bucket loads at its left end (above) and deposits dirt at its right end, more than one hundred and seventy-five feet away. support a man. Its tread is light because its giant shoes, seven feet wide and forty- four feet long, spread this weight over an area half as large as an ordinary bungalow. When one was delivered for work on the Florida ship canal, it was assembled at the station; it then "tramped" eight miles overland to the job, saving an immense amount of trucking expense and labor. The cab, which from the front looks much like a ferryboat, is a nest of giant motors—a big five-cylinder Diesel, the main power plant; а couple of big 100-horsepower elec- tries, which swivel the dragline on its base; and a battery of smaller motors that pump oil keep water circulating, clean the air for the intake, and generate power for the lights—for on a big job they don't stop at night. Powerful floodlights bathe the exca- vation with their brilliance. Weather doesn't This dragline scoops up enough dirt in one “bite” to fill a waiting truck to overflowing. Note men at work in pit. When the boom dips into a deep hole, the operator is so far above his work that dis- torted perspective makes distances deceptive. Pit men below wigwag where to drop the bucket, using a private sign language of their own development. Now and then the oiler must go up the nar- row cat-walk along the boom and lubricate the sheaf of pulleys at the end. It takes nerve to creep along the latticed frame in a stiff wind while the big machine monotonously weaves back and forth. As you look down, things on the ground seem small, for you are as high as a ten-story building. Objects blur before your eyes as you swing along on the boom at forty miles an hour. Up the center of the latticed boom, the cable races along, first in one direction, then the other. It is almost as thick as your wrist, a one and three-eighths inch bundle of twisted strands of steel, for it must stand a terrific pull when the One of the biggest draglines in the world (above) at work in_an Iowa coal mine. The machine reaches down into the cut, strips over- burden away, gouges out operator gouges the twelve-yard bucket into hard, rocky formations. When he lets go, down it plunges, 154 feet a minute. The “pit man” waves his hand; the boom whips like a trout pole as the power comes on and the bucket scoops into the earth. Cables taut, it begins to move again as the cab smoothly turns on its seventy-six conical roller bear- ings, as big as dinner plates in diameter. As it nears the end of its arc the bucket begins to descend, while huge asbestos-block brakes check the cab’s pivot. With the precision of a well-oiled clock, the bucket halts directly above the waiting truck and tilts. A single bite fills the big truck to overflowing and off it starts, while the operator gently flicks his levers and starts the great dinosaur moving again—all within a few minutes time. This big machine can pick up a load of dirt, pivot 180 degrees, and set it down nearly a block away. It can reach down 104 feet into an excavation, bring its bite of dirt to its own level or higher, or deposit it fifty-nine feet above where it stands. Or, it can “step” forward or back and add another seventy feet to its reach. Engineers on the Florida Ship Canal faced the problem of moving huge quantities of dirt over a distance too far for one ma- chine, yet too short for trucks to haul it efficiently. They de- signed a machine that looks like a gigantic bird with outstretched wings. It isa huge walking drag- line with a 175-foot arm extend- ing from each side. Along each [Continued on page 120] The giant machine, with mighty rumbles and groans, arches the eccentric cams on its two sides, raises itself on its huge flat-footed shoes, and hunches forward, seven feet at a step. Then the eighteen-ton shoes lift and move forward ready for another step. The machine would make no speed records—its average gait is about a fifth of a mile per hour; yet it can wheel sharply, turn at right angles, or sidestep like some huge, awkward duck. Steering is just like backing a trailer. Point the boom the opposite way from the direction you want to go. Marshes, sand hills, mud flats, don’t make any difference to this fan- tastic creature. Despite its million pounds of weight, it can walk over any ground that will 54 matter, either. The operator is snug behind his glass windows and it’s warm by the big purring Diesels. Not even a desert sand- storm halts operations on the All-American Canal job; the machines are equipped with special air cleaners that take out grit that would score cylinder walls. One man doesn’t operate one of these giants alone—he has an oiler and several “pit men” to help. Certain parts of the machine have to be oiled every two hours, others every four, so the oiler has a continuous round of duty. On big parts like the cams which cperate the walking shoes, he can smear heavy grease with a paddle. Other bearings take a good grade of lubricating oil. Modern Mechanix a load, and swings it back out of the way. One bucket load represents work of hundreds of men. Regardless of the job. there is a dragline fitted for the work. Because of its big flat feet, this medium-sized dragline (right) can safely “walk” back and forth over the mud without fear of sticking as it scoops away at its job on the banks of the Columbia River, helping to con- struct Bonneville Dam in the state of Oregon. December, 1937 55

Page 186

SHOULD PILOT FAIL TO MAKE NEXT RIDGE HE WILLBE FORCED TO LAND. Ei: PANORAMIC VIEW OF TYPICAL Si ОАК А $ EASIEST METHOD OF ACCOMPLISHING LONG-DISTANCE FLIGH E m SOARING PLAN `A 5 GE аме 3 “EASIEST WAY TO REMAIN WHICH ALTITUDE IS GAINED ON CLOUDLESS, DRY DAYS ———— — UR Ww N THUNI ES s ife - SCRAPS OF PAPER 7. 4 BLOWING za UP FROM GROUND SAIL PLANE HEADING FÓR LARGE CUMULUS CLOUD = CERTAIN SIGN TO PILOT OF RISING AIR CURRENTS. SEE EXPLANATION AT LEFT CLOUD-HOPPING ~ UTILIZING CLOUDS FOR DISTANT FLIGH hk SMOOTH FLOW OF AIR EDDIES - B DEFLECTED STEADILY TURBULENCE UP __ CUMULUS. E THERMAL SOA! 522 WARDS proach to true bird- like flight lies in the operation of soaring glid- ers or “sailplanes.” Light in weight, with airfoils designed to provide maxi- mum lift with the least forward motion, the sail- plane, with a skillful pilot at the controls, takes ad- vantage of rising thermal (hot air) currents or air deflected from ridges of hills below. Artist's sketch shows various methods by which famous soaring pilots have made flights of 300 miles and attained altitudes of 10,000 feet. m 2 А MANEUVER REPEATED AS SEEN AS SUPPLY OF CLOUDS PERMITS. Modern Mechanix December, 1937 Few thrills can compare with that of riding the wind in a sail- plane. In Germany, where soaring has developed its greatest following, over 12,000 sailplanes are flown by the nation's 50,000 glider pilots. Top—A sailplane sets out for a flight over a valley. Above—Carrying sailplanes to the top of a hill for some ridge soaring. Left—Studying a map to determine most likely soaring terrain. Upper left— Time out for re- freshments while waiting for better air currents to develop. 59

Page 187

Flying a home-built plane (right) is a privi- lege enjoyed by resi- dents of only a few states. Right lower— An “Air Camper’’, built from MM Flying Manual (1932) plans. Circle—-Many men now prominent in the aviation industry can be thankful that more liberal air laws were in force during their early days, enabling them to secure low-cost aviation knowledge through construction of their own planes. Above—Many an amateur built his plane in his back yard. 60 Are HOME— Letters from readers indicate a rebirth of interest in amateur avia- tion field. AN the amateur airplane builder success- fully construct a light airplane which he can depend on to perform reliably in the air? Having constructed it, can he use the knowl- edge thus acquired as a stepping stone to a worthwhile job in aviation? The answer is, “YES—if it weren’t for government restric- tions that keep the amateur plane builder grounded except in a few liberal-minded states that encourage amateurs.” Home-built aircraft, if constructed to re- liable plans, can be as safe as any aircraft of equal size and power that carry an NC license. The experience of Oregon, and several other states that permit home-built aircraft to be flown, bears out this statement. Modern Mechanix Built Planes Safe? Above—Amateurs CAN build aircraft that rival commercially- built planes in craftsmanship, design, and beauty of finish, and——they are safe, too, as records prove. Below—An amateur's partially constructed plane. Note excellent work. From 1929 to 1933, inspired by the belief that thousands of young men throughout the country were intensely eager to own and fly their own airplanes, МорЕвм МеСснАМІХ pub- lished annual Flying Manuals containing re- liable plans from which amateurs could, and did, construct dependable light airplanes at a moderate cost. The sales figures of the manuals proved that our belief was correct, and Mopern МЕснАхтх only stopped publish- ing an annual Flying Manual (although back issues of the 1931-32-33 editions are available at 50 cents: each) when federal restric- tions on the flying of home-built planes were adopted by a majority of the 48 states. Recently, we received quite a few letters from readers interested in building airplanes —letters asking us to provide the latest in- formation regarding government laws on the subject; asking us to campaign for more liberal laws relating to the building and flying of home-built planes; and letters urging us to propose some plan that would help the light plane enthusiasts and still be approved December, 1937 EE AE The welded tubing motor mount of the home-built plane in the upper photo can be favorably compared with any found on commercially built “flivverplanes”. Lower photo—A home- built airplane powered with a converted Ford auto engine. by the government aviation authorities. The re-birth of interest in home-built air- planes, as indicated by the number of letters received, caused Морквх МЕСНАМІХ to inves- tigate the possibility of changes in the laws now in force. Sad to relate, there seems very little chance of any changes occurring in the near future, if ever. A bulletin issued by the Bureau of Air Commerce states that its engineers feel that the requirements for light airplanes can be [Continued on page 147]. 61

Page 188

Above—Scraping loose soil from dried adobe slabs. Right—Heavy timber poles are used to make the door frames. ANTASTIC as the statement may seem at first glance, it is quite possible for any- one without previous experience in building to construct a modern, durable and artistic dwelling out of mud, or—to use the old Spanish-Californian name—adobe. This has been proved by a number of residents of the San Ramon Valley in central California. 64 Rows of adobe bricks drying in the sun. The main requirements are a supply of ordinary dirt that does not contain tog high a percentage of sand, enough water to thoroughly dampen the adobe mixture, and plenty of sunlight. Add to these a truly Spanish disregard of time, infinite patience and a strong pair of legs, and you are as well equipped as others who have successfully built their own houses out of native soil. It is well known to students of California history that most of the missions built by the Spanish padres who first explored that state were made of adobe. The prime reason for this was the scarcity of timber in some sections. Yet, after more than a century of Modern Mechanix The roof rafters, of native timber, are supported at the tidge by a log extending through each gable end wall, as shown in above photo. Right—Setting in the window frames. Below —When completed, the outside of the novel house is whitewashed to create a real Spanish appearance. use, many of the old Cali- fornia missions are still standing and habitable. In Mexico and other longer settled countries, adobe buildings over two hundred years old are still occupied. During the past few years a revival of interest in adobe construction has taken place in California. Although he does not claim the distinction, Harry H. Hindman, a resident of San Ramon Valley, is credited by December, 1937 Modern adobe dwellings are easy to build. his neighbors with being the "pioneer" of this renaissance of an ancient craft. Hind- man's adobe house has served as a model for a number of others in that part of California. Departing radically from the classic Spanish design which consisted of a square, box-like structure surrounding a court or patio, Hindman and his neighbors have built [Continued on page 148] 65

Page 189

F YOU'RE looking for a new iceboat design, you'll like Polaris, the latest creation of the Hudson River type and a fast, trim racer with a moderate rig. This craft is a departure from the usual "banjo" cockpit model in that the crew \ sits upright and steers like а car. b A comfortable boat in heavy winds, b \ Polaris is 20 feet long and carries 90 A. Y square feet of sail No jib is neces- sary, as this sail has proved useless on iceboats. There are two cockpits, one located in front of the other. The T-angle iron runner blades prescribed are designed for sail- ing in snow as well as on clear ice. The laminated backbone con- struction, which is relatively simple, makes the hull ex- tremely staunch and check- proof. Polaris is steered by remote control with the steering quadrant coming back into the fore cockpit. Specifications given here provide not only for a weatherable craft but an attractive one. At the outset, get a good conception of the 72 Modern Mechanix construction by studying accompanying plans. Note that Polaris calls for improved methods of building; so keep in step with modern ice- boating by adhering to details. Clear, straight-grained Sitka spruce should be used for the side walls of the backbone or center body. Saw the 34-inch stock of 20- foot lengths into 2-inch strips for the lami- nating work. Reverse alternate ends of the strips so that the wood, when glued up, will bear greater strength. For appearance's sake, alternate strips of mahogany or walnut may be placed between spruce. But it would be vain to glue the strips without reversing the grain, as no benefit will result. Casein glue is essential because it is stronger than the wood. Mix the powder- form glue with cold water and beat until it becomes a thin batter. * To laminate, glue the strips as aforemen- December, 1937 The bottom of the backbone is shown in the photograph above. Note how the crossed steering cable is drawn taut around the 8-inch grooved wheels with a turn-buckle. Left—The laminated deck with tiller and sheet traveler ` just ahead of the fore cockpit. Drawings should be followed so as to obtain correct hull shape and the proper spacing for the bulkheads. tioned to build 12-inch wide side walls. Clamp the job and allow the glue to dry 24 hours before removing the clamps. Chisel away the glue which has oozed from the seams. Now taper the sides to the dimensions given in drawing. The bottom of the sides bear a 2-inch arch. The bow, or head piece of solid 4 by 6 by 615-inch oak, is glued between the fore ends of the sides and screwed with 2-inch F. H. brass screws. Work back from the bow in placing the bulkheads at the required distances. Use 3%-inch plywood for bulkheads, bordered with cheek pieces of 34 by 1%-inch pine. Fasten the plywood to the frames flush. Spread the side walls until the proper width is obtained; then fit in the bulkheads by beveling as necessary. All bulkheads forward of the cockpit сз 7

Page 190

иг" HOLE RASS CHAFING PEATE ЕА. SIDE ет LAMINATIONS Та" X 1-5/8" OAK GRAINS REVERSE BEVEL 45 OR 60 DEGREES SECTION THRU CHOCK RUNNER uie should have 2-inch air holes to ventilate the hull To bring the back ends of the sides together, for the stern-piece, use a light rope sling twisted with'a club. The stern piece, of 4 by 10 by 10%-inch oak, is beveled to fit the taper of the sides, between which it is glued and screwed. А special bulkhead must be constructed for the rudderpost. This is described in an ac- companying sketch. Between the third and fourth bulkhead, at the bow, a fore and aft wooden plate is fitted to support the mast step. All bulkheads, the mast plate, bow and stern pieces and the rudder post block are flush with bottom and top of side walls, at their respective stations. Next cover the bottom with % by 2-inch pine planking, fastening it to the bulkheads and sides with 1%4-inch brass screws. Round the corners of the bottom slightly with a plane. The deck, of % by 2-inch spruce or ч. Angle iron hobblers are welded to 14-inch iron plates and the entire unit bolted to runner plank. Modern Mechanix SCREW OVERALL TOENDS > LENGTH 2 1" SQUARE x 8"GROOVED QUADRANT WHEEL PIN: I TO PIPE l8xl'DEEP gu 4 x ||" PIPE A7" RUDDER POST SLIDING FIT FLANGE SCREW OR BOLT TO DECK x 4 xi5" PIPE a TILLERPOST 2 нок / WHEEL-PIN TO БЕ! 2" X 12" SOLID EYEBOLT pine, is glued to the side walls and bulk- heads and fastened with screws. All screw heads, wherever used on Polaris, should be countersunk and covered with plastic wood. Before gluing the gunwhales around the cockpits, glue 1 by 1%4-inch oak ribs across the bottom and inner sides of the cockpits. Cut rib tops flush with top of side walls and cover gunwhales 1% inches wide. The hole for the tiller post is 34-inch diameter drilled 3% inches from the fore end of the forward cockpit. The 34-inch diameter rudder post is 7 inches from the stern. [Continued on page 124] December, 1937 SPRUCE RUNNER PLANK 13' 0” LONG V4" IRON PLATE l2" DRILL FOR Иг" Qp—*— MACHINE BOLTS в" DRILL м2" R KING BOLT р 3" X 3" CN IRONS UT DETAIL в" WELD 75

Page 191

METHOD OF LAYING OUT A 5—POINT STAR by Ray J. Marran F YOU desire to make something unusual and out of the ordinary to brighten the home at Christmas festivities, something that will add cheer and decorative novelty to the Christmas dinner table, try your hand and power tools in producing a few of the novelty candle holders illustrated on these pages. All of these holders were specially designed for the Christmas candle. They are easily and quickly constructed by cutting the parts on a small jig saw and a lathe. When carefully painted with several coats of quick drying enamel in the regulation Christmas colors of red, green, white and silver, these candle holders make exceptionally attractive and appropriate center-piece decorative units for the Christmas table, or for the mantel shelf. Cut the parts from white pine and three-ply paneling, following a design unit similar to those in the illustrations. To lay out a perfect 5-pointed star, scribe a circle The jolly Santa Claus chara. “А” the desired size. Divide ters shown below are cut the diameter into Y4—points fi thi: 1; d d at- E tached to a 4inch pine base. F, B, C, L and I. Scribe the These Old English Carolers are cut from thin plywood, laid out to the 12-inch pattern shown. 78 Modern Mechanix i 200 The Santa Claus candle holders pictured on the opposite page are made from either this pat- tern or the one illustrated below. Before mounting, paint figures. circle ^B". Divide the line “С” to “В” into 1/3—points B, E, D and С. The line from “І” to “D” will be exactly 1/5 the circum- ference of the circle “А”; this measurement is used to mark the points J, K, G, H and I. Straight lines drawn to these points form the outline of a perfect 5-pointed star as shown. The stars required for the decorative unit are then cut on a jig saw. Stars cut from 3- ply paneling may be cut four to six at one Left—Before cutting the star candle holder to shape, drill a hole in the center of the plywood block large enough to accommodate the tall white or red Yuletide taper. time by bradding the stock together as shown. Note that a %4-inch center hole for the candle butt is bored in the plywood before the design is cut. Star candle holders may be used as a single unit; or they may be mounted on a circular disk cut from %4-inch stock and painted aluminum or bright red. A combination of stars, mounted on a base- board, or elevated slightly with round up- rights, makes attractive decorative units for three or more Christmas candles. The base is enameled glossy red, the stars glossy white and the trees a combination of bright reds, greens, yellows and silver. [Continued on page 126] The craftsman can vary the antics of the Santa Claus characters by making several different kinds. In each instance they are made to 1/2-inch squared patterns, laid out on tissue paper or sketched directly on the wood. The characters are then cut to shape, sanded, painted and attached to the base. December, 1937 79

Page 192

OMBINING the beauty of natural walnut with shining brass fittings, this useful and attractive nut bowl and mallet allows the craftsman to display his skill twofold. While both а wood and a metal turning lathe were used in making the original set, the potential constructor will not be handi- capped if he does not possess the latter piece of shop equipment. Lacking a metal lathe, the mallet rings can be cut to the required lo-inch height from brass tubing and shrunk to fit over the ends of the walnut mallet head. Otherwise, the mallet may be turned in its entirety from solid brass. A form of opening flower motif is imparted to the bowl although its size prevents this idea This walnut and brass nut bowl is a distinctive workshop project. from being obvious. However, the lines are distinctive and very appropriate. Turn the bowl from a block 2 inches thick and slightly more than 10 inches in diameter. Before the center spindle is turned down to exact diameter, bore a %-inch hole, 1-inch deep in its center, make a similar hole in a block of walnut or other appropriate wood with the grain running vertically. Glue the flat and also the dowel joints, bring the tail stock center tight against the piece and let the glue set. Get and smooth a ring of brass about jg-inch thick, %-іпсһ wide and 2 inches in diameter. First turn down the top of the upright so the ring barely starts on. This turning should have a slight taper. Тар it snug, start the lathe and, holding a block of wood against the brass, make it quite hot by rubbing. This expands the brass so that it can be driven tightly against the shoulder before cooling. The whole bowl is then gone over lightly, turned to shape, sanded, rubbed and finished. Lacquer, shellac or var- nish, which is later rubbed with No. 000 steel and finally polished with wax, provides а good finish. The mallet handle is "The mallet head is turned down to а spindle and the YA by 2-inch brass rings slipped оп and shrunk in place as pictured above. Left—The nut bowl near the stage of completion. Polishing is done with the project attached’ to the faceplate. Right—After partially turning the bowl. shape the anvil stud and shrink a 1 by 2-inch brass ring-over it. 80 Modern Mechanix After completing the lathe operation on the mallet, it is placed in a f simple and a hole drilled in the center for insertion of the handle. turned to shape from a maple dowel. The head is turned down to a spindle and the brass fer- rules of brass to j;-inch in width, diameter and wall thickness shown. In the same manner as was described above, the brass rings are heated and driven to a tight fit. For the walnut, filler should of course be used to fill the grain before applying the finish. The whole unit can be made entirely of walnut, or the bowl can be turned from figured gum or birch, while the mallet and top half of the center spindle, or “anvil,” can be of walnut to provide a pleasing contrast. Completed this bowl will take two pounds cf nuts without appearing over full It is an ideal wintertime project and, of course, has commercial angles which the enterpris- ing home shop owner can work out to his advantage. December, 1937 | .BRASS RING SHRUNK ON — WALNUT н/2" a Y NS ANOTHER ANVIL, SUGGESTION If a solid brass mallet head is used, it can be of the same dimensions as the brass trimmed wood head shown. or shanks can be turned between head center and the end faces. Another way to provide a neat brass trim is to dispense with the glued-up center block by soldering a large, flat head wood screw to the under side of a brass disc about %4-inch thick and turn the screw into a hole drilled in the original center portion. This will make the anvil just %4-inch higher than the bowl rim, but the heavy metal will not blemish with use as much as will the end grained hard- wood block. When this arrangement is used the center hole must be slightly countersunk to accommodate the screwhead so as to per- mit the brass disc to fit tightly against the wood. The protruding edges of the solid brass are then turned down flush with the wood center and finished in the usual way. by Dale R. Van Hom

Page 193

ПР CARDBOARD HE model locomotive presented here is of all cardboard and wood construction, even down to the trucks, its total cost being in the neighborhood of twenty cents. The materials, with the exception of glue and cardboard, were bought in the five and ten. However, the trucks may be purchased complete with a motor and the rest of the con- struction built up of cardboard from “О” gauge plans given here. Metal may be used in place of the cardboard and wood. + мг"

3 18 COPPER WIRE 8 PIECES SPACED LE REGULARLY = 1" aT SC OIL COOLER ASSEMBLY

2"x 43" piece ROOF 2f WIDE GLUED TO ROOF

CELOPHANE 4 FRAMING GLUE TO BACK OF OPENINGS

WINDOW DETAIL. PRESS DOWN THRU : RING "8" AND GLUE HEADLIGHTS PIECES TOGETHER (AIR TANKS MADE IN SAME MANNER)

SUPPORT Ж 18 WIRE BRACKET MUFFLER DETAIL

ENO PLATFORM (GLUE TO FLOOR) і BALSA

FLOOR (3//6" PINE) т

WIRE PIPES STEPS

ROC \ DETAIL OF SIDE TRIM EXHAUST SC 15/16" DIA, CONTOUR 2 STACKS 7 5. ee eee a * Сой T ^l =

3/4" DIAM. BONE oR T X DETAIL METAL RING OF WHEELS ki

WIRE END-TIE CUT OUT FOR THIRD RAIL 9/16 INNER FRAME TRUCK DETAIL

эле" 12"

CONSTRUCTION DETAILS ALL CARDBOARD UNLESS OTHERWISE NOTED

BALSA . INNER FRAME VARIATIONS t | = INDICATED BY BROKEN LINE An Ó Gauge 0й- WIRE- GLUE ТО j 8344" ~ OUTSIDE FRAMES E DIAM. ` OD „г< 190

Electric Locomotive by Herbert Lozier — CONSTRUCTION This unique model is an authentic ver- sion of a Union Pa- cific oil-electric loco- motive. It can be built for 20 cents.

As either a display model or motor driven, this flashing oil- electric locomotive is an interest-

Overall dimensions of the model locomotive are shown above. Construction is shown in perspective form in details on opposite page. This locomotive is a composite of several different types used on the roads. Either the mufflers or exhaust stacks may be left off at will, de- pending upon the builder's creative desires. Begin the model by making the trucks, building them up on a section of “0” gauge track so as to avoid any chance of mistakes when spacing the wheels. The pattern for both inside and outside frames of the trucks will be found on the accompanying plan. Make the inside first by folding the patterns over into box shape and gluing them securely at the ть. model can be fitted with seam. After they have dried, SEM EO (ашке то Бу add the top and pivot disk. tank and allowing an opening Я in the floor for insertion of [Continued on page 140] the motor, as shown at right. CUT OUT FLOOR TO ACCOMMODATE | MOTOR FRAME |

95 CHANGES NEEDED TO INSTALLMOTOR (CROSS SECTION)

Page 194

HERE are many instances where it would be convenient to apply a moderate degree of heat to a small area. Keeping small quantities of paraffin warm in the microscope laboratory, rapid drying of small objects or areas, instances where a hot water bottle might be used but where ordinary bottles are too large and clumsy—these are but a few examples. For such work, the simple and inexpensive lamp illustrated will be found useful. The lamp, the general idea for which was origi- nated by G. F. Prideaux, a Cleveland, Ohio, lighting engineer, consists of a 10-watt bulb enclosed in a metal housing that concen- trates the heat and light rays at one small spot, about the size of a silver dollar. For assembling the heat applicator the fol- lowing materials, most of which can be ob- tained at a local hardware or dime store, will be required: 1 brass socket for stand- ard medium screw base bulb, preferably keyless; a % to l-inch piece of brass tube, threaded to fit socket hole; 1 nut The perforated portion of the shaker cap is removed with a sharp knife or chisel (above) and the roughends turned down with pliers, as shown in photo below. A wooden handle, 10-watt bulb, 6-foot fixture cord, and inexpensive aluminum drink shaker constitute the materials used in the ap- plicator’s construction. to fit threaded tube; 1 aluminum drink mixer of the type illustrated; 1 10-watt, clear-glass lamp bulb; 6 feet of lamp or asbestos-covered heater cord; 1 separable plug for connecting to lamp socket or wall outlet; 1 wooden handle, which can be a 5-inch length of broom stick. If desired, a spring-type cord protector, like the ones found on electric iron plugs, can be added, for further protection of the wire. In the bottom of the drink mixer, punch a hole and enlarge it so that it will receive the threaded nipple. Connect one end of the wire to the socket, screw the threaded nipple into the socket, and run the wire and nipple through the hole in the mixer bottom, from the inside. Clamp the socket in posi- tion by screwing the nut over the nipple, centered with respect to the sides of the con- tainer and attach the connection plug to the other end of the wire. It is a good idea to provide some means of preventing the edges of the threaded nipple Ee [Continued on page 132] One of the applicator’s many uses: an aid in relieving rheumatic and muscular pains. Though small in size, the 10- watt bulb, shown installed in the shaker, will provide an abundance of heat. Below— Wiring of the socket is done before the applicator is as- sembled. Ап electric iron plug spring, fitted to the end of the aluminum shaker, will eliminate wite breakage.

Page 195

VERY motorist knows, only too well from past experience, the numerous troubles that develop in the car's motor dur- ing the winter months. Run-down batteries, broken high-tension cables and short circuits in the distributor are only a few of the many annoyances to be contended with. То say that these temper-shattering troubles can be avoided is by no means an exaggeration. With a better understanding of the factors involved in the motor's proper operation, When the car battery is too weak to permit starting, even by cranking, the problem may be solved by inserting а doorbell transformer in the ignition circuit as illustrated at right. Once motor has warmed up, original battery connections may be restored. Lower right—If a small quantity of cylinder oil placed outdoors overnight will pour from the bottle the next morning, its viscosity is satisfactory for winter use, Below— Starting troubles are often traced to carburetor and manifold winter starting can be made just as pleasant as it is during the summer. In order to introduce and compress a charge of fuel it is necessary that the motor turn over at a fair rate of speed. Unless the summer oil has been replaced with a light winter lubricant, this is impossible. In mod- erately cold climates the crankcase should be drained and refilled with a good grade of oil having a viscosity rating of S.A.E. 20 or 20-W. In localities where the temperature hovers at sub-zero, an even lighter oil, such as S.A.E. 10 or 10-W, should be used. Any competent gasoline station attendant will ad- vise the correct oil for use in your car or IGNITION SWITCH Y 4 7*— FROM BATTERY GROUND T TO bed FRAME Y a 1 1 i Ly DISTRIBUTOR EXPOSE OIL. IN COLD WE. Sometime all three may be at fault. VAPORIZE FUEL BY PLACING A HOT ELECTRIC IRON AGAINST MANIFOLD DISTRIB— AND WIPE OFF BOTH INSIDE AND OUT- SIDE OF CASE — FOLLOW WITH ALCOHOL WIPING THE ROTARY AND POINTS This photo of a modern automobile motor shows where to look for trouble in the ignition system. Trouble often occurs in the cables, distributor or generator. CONNECT & STORAGE BATTERY CHARGER Right—A simple way to charge a weak battery. TO you can determine this yourself by a sim- ple viscosity test. Place a tablespoonful of oil in a small bottle and allow it to remain outdoors overnight during a cold spell. If the oil, after being exposed to the elements, be- comes too hard to pour, you may be sure that it is not suitable for use in the crank- case, In order that the gasoline is converted into vapor for firing the cylinders, a cer- tain amount of heat is required. Even the best grades of gasoline cannot be expected ® to function properly unless the chemical changes they require are given proper consideration, The quickest way to ac- complish vaporization of the fuel is to heat the manifold of the engine externally. This may be done by resting an electric iron against the manifold or playing the flame © of a blow torch on it for a few minutes. With this simple treatment the motor will start almost instantly if the engine is first turned over a few revolutions with the choke momentarily pulled out before the ignition switch is turned on. [Continued on page 142] Many winter starting ‘annoyances can be remedied if the suggestions outlined in the illustrations at left are carried out. 1—An electric iron held against the manifold will aid in vaporizing the gasoline. 2—Clean both inside and outside of bakelite distributor with a clean cloth and alcohol, then (3) file rotary points and contacts. 4-—То prevent power leakage, waterproof high- tension cables with $several coats of shellac, varnish or clear lacquer. 89 e TERMINAL OF GENERATOR CUT-OUT, WITH OTHER TERMINAL TO FRAME OF- CAR TO MAINTAIN STRONG CAR BATTERY

Page 196

by E. Mason Marcus ROBABLY the most discouraging factor to all embryo home chemists is the lack of costly equipment that is outlined as neces- sary in most experiments. The experiments described in this article are unique in that the only necessary equipment consists of a few test tubes, jars, a pan, and a teaspoon. Perhaps you are wondering what a col- loidal chemistry is all about. Colloidal chemistry is concerned with suspensions, emulsions, and all other phenomena of finely divided particles. Colloids are quite common in our every- day life. Milk is a colloid Steam, fog, ink, butter, and gelatin are ай colloids. The red of a beautiful sunset is due to the finely divided colloidal particles of dust suspended in the air and refracting the light. Some of taining unflavored gelatin, silver nitrate, Experiments in Ordinary household gelatin, vinegar, wa- 4, ter and a few com- mon and inexpen- sive chemicals provide all materials 1 for performing these ‚Ш novel experiments. these colloidal particles are so small that they cannot be seen in a regular microsccpe which shows particles in trans- mitted light but must be viewed in an ultra- microscope which uses a dark-field and the particles are seen by reflected light. There are two types of colloidal systems. One of these is a watery system and is called a "sol" The type that we are going to ex- periment with are called "gels" for they are in the form of a jelly-like substance such as the gelatin desserts which we eat. There is a beautiful phenomena in the chemistry of gels which we call rhythmic banding. These can be made in gels of gela- tin or of silicic acid. Beautiful bands of bright red and colorless can be made to ap- pear in an ordinary test-tube. АП of these Rhythmic banding effects, as picture at left, are produced by mixing V5 tea spoonful of water glass with 2 teaspoonsful of water. To this is ciue a few crystals of potassium iodide dissolved in 2 teaspoonsful of vinegar. ‘When poured into a test tube a jelly-like mass is formed. Adding a solution made from a few mercuric acid crystals, will produce beautiful red bands. Below——Cross-section view of Liesegang's rings formed from a solution con- or lunar caustic, and water. Modern Mechanix Anyone can perform these unique experiments in colloidal chemistry. The only equipment required is a few test tubes, a teaspoon, pan and several small bottles. experiments have a gel for a base. For the first experiment in which we get the red bands, we will use silicic acid for a base. Do not let the name scare you, for silicic acid gel is nothing more than a mixture of common water glass and an acid such as white vinegar. It can be made by taking lo-teaspoon of water glass which can be purchased at any hardware or drug store, and mixing it with two teaspoons of water. This forms solution “A.” Solution “В” consists of two teaspoons of white vinegar or 5% acetic acid which is found in all vinegar and which gives it its sour taste. When solution “В” is poured into solution “А” a colorless solid mass is formed, known as pure silicic acid gel. It will be noticed that it is quite rubbery and will produce a metallic ring when the test-tube is tapped. To make the red bands in the test-tube, a few crystals of po- tassium iodide are added to the acid solution “В,” and then "B" is added to “A.” When this has set, which should require no more than a few seconds, a [Continued on page 130] December, 1937 This unusual “lead tree” experi- ment provides one of the most un- usual displays in colloidal chemis- try. In a small vial place V5 tea- spoonful of water glass mixed with 2 teaspoonsful of water. Next dissolve a few lead acetate crystals in 3 teaspoonsful of white vinegar and add to the water and water glass solution. Insert a small strip of zinc in the vial and allow it to remain submerged for several days. Resulting effects are shown in these pictures. Тор picture shows the "lead tree" after 2 hours while at left tree is shown after 24 hours.

Page 197

Hitching a Microscope Many set-ups may be used in taking photomicro- graphs. Неге a plate camera is supported over the microscope on a tripod, while blocks of elevate the microscope to correct height. lamp light source appears at the extreme IHE mere inspection of bugs and other specimens under a microscope, or the making of permanent slides, is a fascinating pastime. But photography through a micro- scope is something else and a job worthy of the most enthusiastic devotee and one of the most engaging of all hobbies. · It must be admitted at the outset that photomicrography is probably the most diffi- cult of all forms of the photographic art, assuming that perfection is the goal. But reasonably good pictures can be secured by the beginner within a week. Thereafter, as in any type of photography, improvement is a matter of skill gained by patience, care and practice. Of decided importance is the fact that con- trary to expectation, one does not need a lot of expensive equipment for this work. Any type of camera can be hitched to a micro- scope, and the accessories either purchased 94 The results obtained when a slide of human blood is photomicrographed are shown in the above series of pic- tures. The first print made (1) showed lack of contrast. In the next, (2) orthochromatic film was used with a moderately short exposure. Results still were not satisfactory, so a longer exposure was given the en- suing print (3) with noticeable im- provement. The amateur expected better results and purchased a set of light filters. The first print was jarred during exposure (4) so an- other attempt was made. In realign- ing the lens, the condenser was moved slightly, resulting in an off- focus image (5), but the experi- menter finally triumphed with excel- lent photomicrograph of blood (6). a few at a time or made at home, according to preference. Naturally, the better the equipment, the better the results. But it does not follow that one should put off trying his hand at a few pictures just because his in- struments happen to be of the cheaper or cruder sort. Take some shots anyway and learn the rudiments of the game; it's loads of fun and good experience. Better pictures will then come more easily when a better outfit is obtained. Complete photomicrographie apparatus is commercially available at prices covering a considerable range. Some of the professional outfits run into elaborate and expensive de- signs that would appall the novice as much by their complexity as by their cost. Never- theless all of them, from simplest to most in- tricate, operate on a single, elementary principle that we can easily and quickly demonstrate. Roll up a cone of cardboard and tie or glue the overlapping edges, so that the smaller Modern Mechanix To Your Camera by Julian D. Corrington, Ph.D. Photomicrographic sli from. Wards Natural Science Est.. Tne. opening of the ape: will fit snugly ove: the eyepiece of the microscope, the cone being inverted, base upward. This base should be some 10 inches above the eyepiece and from 4 to 6 inches in di- ameter. Paste a sheet of white tissue paper across the open base. With a slide in position on the microscope stage, and performing the -demonstration at night in a darkened room, shoot as much light as possible through the microscope, se- cure a focus, and there is the picture of the object upon the tissue paper. This is actually a case of projection, just like that of the mo- tion picture or lantern slide projector. Now it is obvious that if we were to replace the tissue paper with sensitized film or plate, we should be able to make a photograph of the object in this same manner. And that is just what is done by photomicrographic December, 1937 Photographing microscopic wonders is a new and inter- esting hobby. This 9x12 cm plate camera, attached to a home-made stand, makes excellent photomicro- graphs. А sheet of photo mount paper between camera lens and microscope eyepiece serves as a light-tight adapter. Black “scotch” tape will also provide effective results. cameras, which are no more than black boxes; the word "camera" means a chamber and a box is a miniature chamber. When hooked up to a microscope, all of the acces- sories of modern cameras may be dispensed with, since the microscope already has lenses for focusing, and exposures may be made by snapping the light source on and off, thus eliminating the necessity of a shutter. One of the best methods of building your own camera is to center the construction 95

Page 198

Faulty power lines are sometimes re- sponsible for the by Robert S. Kruse, E. E. T IS no good to plug a crack in a rowboat while water is pouring in through a 6-inch hole at the other end. In just the same way one cannot get quiet radio recep- tion with the best anti-noise device while noise is pouring in through some other gate- way—and there are 5 ways for the noise to get in. Let us examine the 5 gates, to see how they may be closed. Very many radio receivers, even when in good repair, are noise- factories on their own ac- count. These noises take the form of hums or A> "Shhhhhh" noises, AN which may per- M "lk ES interference heard on sets. Power com- panies stand ready to track down troublesome lines. ht sockets, worn heating A sters and irons all tend’ to create noise that hinders reception, т NEAR ROOFS br WIRES ES ORDIN NO JOINT T WAVE- SHOR NOISE) ARY BROADCASTS — Described here are three types of noise reducing antennas. Two of them are designed especially for shortwave reception, while the third is for broadcast pick-up only. АП are available in inexpensive kit form. | sist even when the antenna terminal of the set is connected to the chassis of the set. In other cases the hum is heard only when a station is tuned in, and still others the “shush” noise appears only on weak stations or when signals fade down. All these things are design-defects found in both cheap and costly receivers. A really STATIC REDUCING ANTENNA 70' TO 200! Right—In localities where static 15 ex- cessive, an antenna located only a few feet above the ground will often’ re- duce annoying radio disturbances. > p GROUND LINE 98 Modern Mechanix A noise filter consisting of two choke coils and two condensers, connected as shown, will often reduce power line interference. good serviceman will understand what causes them and you may learn whether to trade in the set for a better one or have him make changes in its circuit to get rid of the noise. Sometimes the receiver can be made decently quiet if given a 100-foot antenna but if that seems to overload it, compromise with a 75-foot antenna. On Jack Benny's program, and in the funny papers, any fool noise is called "static," but December, 1937 How to check radio noise at its source. If noise persists when antenna is grounded to chassis, it is en- teringset through the power line. Natural static, as caused by thunderstorms, cannot. be entirely eliminated. Special antennas will aid in partially reducing it. Sharp crashes of static may be reduced in some instances by connecting a G-10 neon bulb across the speaker transformer. there is no mistaking the real article when it has once been recognized. Static is infre- quent in winter and frequent in warm weather, especially after sundown. It never squeals or buzzes as the funny-men say, but is always and every time explosive in nature —a crash or pop for a single "splash" of static on a grating or frying sound but never a steady noise. It cannot be stopped at the source, for nature is responsible, but we can cover moderately strong static by using a larger antenna, as already mentioned, pro- vided we make the antenna merely longer —not higher. Broadcast reception can be made fairly acceptable with an antenna 5 feet high and 100 feet long when the ordi- nary antenna nearly ruins the speaker. Most people now know that pitched noises may be reduced by turning the tone control to "bass" or "low pitch" and accepting the [Continued on page 134] 99

Page 199

BUILD THIS TWO-TUBE by Clifford Peters ГГҮНЕ "Two-Tube Amateur Special" will fill the wants of the future radio amateur, or the person who desires to listen only:to the short waves with all their interesting broad- casts. For the person who now is learning the code, this receiver will supply all the code practice desired. : Simple to construct, the entire outfit can be assembled and wired, ready to operate, during a weekend. A metal cabinet serves the double purpose of furnishing adequate shielding and giving the finished product an attractive appearance. The outfit was con- structed with the power supply as a separate unit to remove the possibility of a. c. hum pickup so predominant in many home-built regenerative receivers, using a power pack. Before starting the actual construction, the builder would do well to study carefully the wiring diagram and the placement of parts. Slight variation of parts placement will not materially affect the operation of the re- ceiver. The builder will notice that the two tuning condensers are connected in parallel. The .0001 mf. variable condenser is used for band- setting purposes, and the .000035 mf. con- denser, mounted near the center of the panel, for spreading the section of the band selected by the band-setting condenser. Although this receiver is not recommended for loudspeaker operation, it will furnish sufficient volume on some stations to be heard throughout the room. It will, in any case, give signals loud enough to be read with headphones. 100 "AMATEUR SPECIAL” Actual construction should start with the panellayout. A cabinet measuring seven by ten inches long and eight inches deep will be found to be most suitable. This cabinet should have a removable panel so that layout and drilling can be done with it removed from the rest of the cabinet. The location for the band-spread con- denser was obtained by drawing diagonal lines from the corners of the panel, and meas- uring up one-quarter of an inch from the intersection of these lines. The centers of the holes for the band-set condenser and the potentiometer are ob- tained by measuring up two inches from the bottom of the panel and two inches in from each side. The pilot light and the “В” switch are located one and one-half inches from each side and two inches from the top of the panel. A plyboard subpanel measuring eight by seven inches deep is attached to the panel by three one-inch angle brackets. The sub- panel is mounted approximately one and a half inches from the bottom. Because the potentiometer and the band-setting con- denser are mounted only two inches from the bottom of the panel, it is necessary to eut sections out of the baseboard to accommo- date these instruments. It will be noted that the power supply is larger than most of those used for receivers. It can therefore be used with an amplifier for this receiver, or as a source of power for a crystal oscillator. The completed receiver as viewed from the front, “В” switch shows at the upper left corner of the panel. The pilot light is at the right. The panel measures seven by ten inches long. Modern Mechanix TUBE BASE DIAGRAMS FROM BOTTOM OF TUBE OR SOCKET GRID САР A switch is placed in the “В” plus lead so that the receiver may be shut off tem- porarily without turning off the filaments. When the receiver is used with a trans- mitter, this “В” switch will be found espe- cially useful. If the entire receiver, in- cluding the filaments, is turned off, ap- proximately twenty seconds are required before the tubes are again at operating temperature. The “B” switch eliminates this time lag. The pilot light indicates that the receiver is turned on even though the “B” switch is turned off. Different values of grid leaks should be uy SCHEMATIC PILOT LIGHT Markings on all parts А Note on photo that C1 and shown in the schematic R3 ate connected to detec- tor tube (6K7) through a grid cap at top of tube. diagram agree with those [ shown on photographs. 098 December, 1937 А 101

Page 200

by Paul Hadley HE popularity of photographie greeting cards increases each year among amateur photographers, who have developed many interesting and unique ways of making them. Yet, there is one branch of this hobby, though especially well adapted to the making of greeting cards, that has somehow been over- looked. This is table top photography, by means of which little scenes can be built up on a table in the quiet of the home, and pho- tographed by artificial light. Many are the effects that can be produced with a few simple "props," such as a toy doll or two, miniature Santa Claus and rein- deer, or other miscellany found in any toy Store. No particular equipment is needed; any available camera that can be focused on objects within a foot or two of the lens is well adapted to the work. As the objects are necessarily stationary, time exposures of any length may be given so that even the most simple lighting can be made to produce good results. All of the accompanying illustra- tions were made with a simple focusing camera, using one or two photoflood bulbs for illumination. Ordinary lighting bulbs would have served just as well however, by increasing the time of exposure. One of the accompanying illustrations shows a small doll seated at a table, much as any child would sit, just finishing a letter to Santa Claus, in which she requests him to bring lots of pleasant things to the re- cipients of the card. This little scene was simply made. The doll was an ordinary ten- cent china doll from the toy store, about 5 inches high, seated at a table made from a small wooden box. For a background, a sheet of white cardboard was placed immediately back of the table, with a window and cur- 104 De | T t " Photographic tains, made from black paper and two scraps of white cloth set up in front. An evergreen twig, decorated with a bit of tinsel, add a bit of Christmas atmosphere. The note was printed on white paper with black ink, and propped into place against the curtain, One photoflood bulb, at the same height as the set-up, and located beside the camera, fur- nished the light. The exposure was made in 6 seconds at f. 22 stop. The same tinsel decorated cedar limb was used in making the other three pictures in which the symbol of Christmas appears. In two of these the little trees, decorated with Though distinctively different, these novel greeting cards are easy to make. Properties consist of odd pieces of cloth, cardboard, two ten-cent dolis and a few miniature “prize package” toys. Draw greetings on resulting negatives with black show card paint. Modern Mechanix “Мы Ж. Your Пип H gifts, in a homelike setting, was made with the same window and wall background, but with the use of an additional doll character. The toys used to decorate the tree were a tint chair from a set of kiddie's doll furni- ture, supplemented with a striped whistle and a few marbles to look like balls. Light- ing for this scene is the same as that used in the first except, that the lamp was moved a bit farther to the left, so that more sharply defined shadows are cast. In the North Pole scene, we find old Santa, himself, about to leave on his yearly round, while the Aurora shines brilliantly around the North Pole. This scene took but a little over an hour in the making and photograph- ing, and proved to be one of the favorites with the children to whom it was sent. In December, 1937 Holiday Cards A small camera and simple props provide all equipment needed to make these clever greeting cards. Simplest of all to make, this card is never- theless very effective. A lighted candle, pen, inkwell and evergreen twig provide a cheery setting for the friendly Yuletide greeting. making this, the table was first covered with a layer of news- papers, and the “aurora” back- ground, of dark colored cardboard with the designs painted on it with white ink, set in place. A half inch layer of flour was then sifted over the paper covered table top and a small pile made where the “North Pole” was to stand. The pole, by the way, was nothing more than a large peppermint stick as sold in all stores at Christmas time. Santa, his [Continued on page 128] Bits of tinsel, an evergreen twig, a doll chair and a pair of china character dolls are incorporated into this original greeting card. The window frame in the background is formed of black cardboard and thin strips of wood. Star and snow effect are painted in.

Page 201

GerLuLom Deverorinc Tanks Are Easy То Make oh POUR DEVELOPER IN RERE “>. » /SHORT PIECES { OF CELLULOID. HUE CBAFFLE CEMENTED TO SIDES OF LID LACQUER ALI PARTS BLACK In order that the developer mix thoroughly when poured into the tanks and all light shielded from solution, the lids of the develop- ing tanks are fitted Ke with baffles made as ‚_ pox shared, de shown in the above i 5 Я This ор 1E ду. fo phantom detail. The Lect А ы 3 valori ехрїеѕ* "тузет" baffle is cemented to ж Ў ч Я 2 : signet cut 13, срасете the lid on short cellu- Y * vain ү the ӨТҮ prous loid tabs. The fun- 3 Ake don nel, on top is ce- р > à Г accomp E aceton mented with acetone. dnt К ока: К polis) tongs sipi stam anting Paintin Pictured at right is a com- pleted roll film tank, loaded and ready for the developing solution. Al- though shown transparent, the tank when in actual use should be given one or more of black lacquer. OST professional photographers develop their negatives by the time and tem- perature method in a tank, to assure results that are uniform from day to day. A high average of good negatives is one of the secrets of the successful photographer. When the amateur wishes to follow this method, how- ever, quite often he is confronted with one or more problems. First, a suitable tank may be too expensive. Again, one of the right size, particularly for roll film, may not be available. Finally, if you wish to make your own tank and are lucky enough to have a skeet of non-corrosive metal, such as monel or stainless steel, it is difficult to put to- gether. Solder cannot be used, as it would contaminate the developer. Heavy sheet celluloid, which you can pur- chase at any auto supply store, is the ideal answer to the problem. It is not expensive, does not affect the developer and can be welded together easily. Hold two pieces to- gether lightly and touch the edges with a drop 106 Modern Mechanix To insure tank rigidity. the bottoms are fitted with plywood and ren- dered waterproof with a sheet of celluloid, secured to plywood with acetone cement. Though inexpensive to make, the celluloid developing tanks will be found superior to many com- mercial types. The photo above shows a cut film tank in use. Below—When winding roll film on the developing tank spool, squeeze the edges of the film. as it is wound up, so that it bulges sufficiently to permit its insertion in the film tracks. of acetone. Like a flash the latter penetrates and makes a secure, waterproof bond. The illustrations show how to make tanks for developing either cut film, film packs or roll film. The roll film tank is supplied with a celluloid spool on which the film is rolled for development. December, 1937 by Kenneth Murray Spiral strips of celluloid are ce- mented to the inside of the spool so that the surfaces do not contact each other during the developing process. Note holes in upper disc for developer to pass through. Make these with a small machine drill. A rubber bulb circulator inserted in the cut film tank insure the de- veloping solution of proper agitation at all times. Roll film is agitated by gently shaking the covered tank. First cut a piece of thin plywood to the desired size and shape for the bottom of the tank, then bend a sheet of celluloid around it to make the sides. Cover the plywood with a piece of celluloid of identical size and flow acetone along the edges so that the two will be bonded to the walls. This forms the real bottom of the tank and protects the plywood from moisture. If the tank is large it is advisable to reinforce the corners and edges with additional strips of celluloid, welded in place with acetone. In the case of the cut-film tank, bend nar- row strips of celluloid and weld them in orderly fashion on either side, with acetone, to form troughs or grooves into which the [Continued on page 136] 107

Page 202

by Alfred Dolid With the equipment arranged in this manner, contact printing is easily accomplished. If desired, the glass bowl used for the acetic acid shortstop bath may be re- . placed by another 5 by 7-inch tray. ^ ULL instructions for developing roll film at home were given on pages 104 and 105 of the November issue of MopERN MECHANIX. The next operation is “printing,” which is the process of producing actual black and white pietures on paper from the developed nega- tives. There are two kinds of photographic "printing"—contact and projection. In con- tact printing, the negative is placed directly against the surface of a sheet of sensitized paper while light is flashed through the nega- tive so that it hits the paper directly. The size of the resulting print is thus exactly the same size as the original negative taken by the camera. In projection printing the negative is placed behind a lens in a sort of lantern, and the image is thrown onto sensitized paper a short distance away. By proper adjustment of the optical system, the print can be made many times larger than the 108 Anyone can make snapshot prints. These instructions tell how it is done. original negative. This form printing is com- monly known as “enlarging.” The person just beginning in photography should learn contact printing first, as it is very simple and requires only one very in- expensive and easily-made instrument — a printing box. This is a plain box, constructed of three-ply veneer or pressed wood, with an electric bulb in the bottom. The top is left open to accommodate a "printing frame," a device for holding the negative and the sensitive paper firmly and evenly together. You can make such a box in less than an hour if you follow the accompanying plans. The dimensions shown are for a 4 by 5-inch printing frame; that is, a frame that takes negatives up to 4 by 5 inches. This is large enough for all standard roll or film pack negatives in the popular amateur sizes. Ап opening in the center of the glass, to take your particular negative, is easily masked Modern Mechanix off with black “scotch” tape, which costs only a few cents a roll. In making the box, be sure that the print- ing frame fits loosely over the top, so that it can be put in place and removed quickly. Besides the printing box, the following items, all obtainable at very reasonable prices from any photo supply house will be needed: an “ОА” yellow filter for the darkroom safe- light; several fresh tubes of *MQ" developer; the same hypo saved from the negative de- veloping process; a one-pound bottle of acetic acid; two trays, one 5 by 7 and the other 8 by 10 inches; a few glass bowls or shallow jars; a wooden clip or pair of tongs for han- dling wet prints and a supply of contact paper. As a starter, get one envelope each of Azo E-4 and E-2 paper. This is semi-matte paper, the first of "contrast" grade for flat negatives and the other "normal" grade for normal negatives. This material is surprisingly cheap and therefore permits a lot of experi- menting. Half fill the 8 by 10 tray with hypo. Mix the MQ developer as per its label for con- fact prints and put it into the 5 by 7 tray. The printing box is of simple plywood construction, made to the dimensions given in the detail at right. A cleat socket, fitted wth a 25-watt bulb, is mounted in the bottom and wired to a radio toggle switch and a length of fixture cord. Printing frame fits on top. December, 1937 Measure out 34-02. of acetic acid, mix with cold water to make a pint of liquid, and pour into the flat bowl or, better still, into another 5 by 7 tray. Last, fill the tall jar with plain water. The arrangement of apparatus as shown in the large picture is a convenient one. To commence, darken the room and turn on the safelight. Don't be alarmed by the bright- ness of the yellow light. Photographic paper is much less sensitive to light than negatives, and can be handled in perfect safety under the “ОА” filter. The ability to judge the "contrast" of nega- tives will come only with experience. Nor- mally-exposed negatives, which have been developed in MQ developer, usually take "normal" grade paper; therefore start with that. Open the printing frame and clean glass pane carefully with a soft handkerchief. Place the negative on it, with the dull (emul- Sion) side up. A sheet of Azo paper is then laid evenly over the negative, with its chemi- cally-treated side against the latter. By ex- amining the paper under the safelight, the [Continued on page 142] — DETAIL OF PRINTING BOX — PLYWOOD STRIPS TO SUPPORT PRINTING FRAME SWITCH СЕ ПО VOLTS. 109 PLYWOOD SIDES

Page 203

New Aids and Ideas For Three narrow strips of wood, each fitted with sharpened nail prods, provide a handy means for extending the legs of a tripod. The strips are attached to the regular tripod with small "C" clamps as is illustrated at left. L-shape cardboard boarders, like the one shown at right, are excellent for determining the correct amount of trimming a Print requires, in order that it shows up most effectively. Once determined, it is an easy matter to mark the print with a China marking pencil and trim it down to correct size. | Left—A 210 v. flash- light bulb and bat- tery, connected in series with a photo- flash lamp, will in- stantly tell its condi- tion. If 215 v. bulb glows, photoflash lamp is in working condition. Below—An ink that will chemically re- act with a photographic print so as to produce a lasting white signature is easy to make. First dissolve 20 grains of copper sulphate in 2 oz. of water, then add 10 grains of sodium chloride (com- mon salt), When this dissolves, add sufficient ammonia to turn it a clear blue color. Finally add 10 grains of sodium hyposulphite (ordinary "hypo"). Apply ink to photo with a gold pen. Above— Where the darkroom facilities аге too cramped to permit drying of film by sus- pending it from a long cord, this clip holder will prove extremely useful. Several spring clothes pins are threaded on a length of iron wire in the Right-—Amateur photogra- phers who take their pictures with a box camera can be sure of level "shots" by equipping the camera with two small spirit levels, The levels are nothing more than automobile fuses partly filled with alcohol or red ink, sealed and attached to the camera with. cellulose cement. If old fuses are not available, short lengths of glass tubing, plugged with small corks, may be substituted. manner shown. The end clips may be attached to a chair with the center clips serving to suspend the strip of wet film. Modern Mechanix | The Amateur Photographer By removing the socket and shade from a flexible desk lamp it can be fitted with a reading glass so as to leave both hands free when "spotting" print blemishes. Where the celluloid backing of a negative is stained or scratched, the emulsion can be saved by application of acetic acid to backing. Attach negative, emulsion side down, to a glass plate with rubber cement. After backing comes off, remove emulsion from plate and wipe off all rubber cement. Very often the presence of small scratches on the surface of a cut-film negative can be attributed to the action of the finger nails from attempting to lift it from the developer. To overcome the difficulty, place a glass rod in tray as shown. The rod will elevate the negatives and permit easy removal. December. 1937 A length of linen fish cord, fitted with a wire hook on one end and knotted at 1-foot in- tetvals, is excellent for mea- suring distance between lens and subject to be photographed. Ап ordinary portrait lens can be used for wide-angle work. Fo- cus images on a ground glass screen and fit camera with a new dis- tance calibration as shown at lower right No. Below——This useful hand reflec- tor consisis of a desk lamp shade and socket fitted to the wooden handle and threaded copper tube of an old electric soldering iron. Light is provided by a size photoflood bulb. No. 1 or 1

Page 204

Seven prints of this "freak egg were sold “for $26 to a news- Paper syndicat HIS camera business gets into your blood. - No matter how good the last roll of film may turn out, you say to yourself, "This shot is undertimed. That one is over. I got too much scenery in this one. Boy, next time will be different!" Not long ago, three men got INO Aen for an evening. All were interested in pho- tography. Two were amateurs, the third а commercial photographer who had a great outlay in equipment. No matter what the shot, he could get it. One of the two alleged 112 еше eis, od This homemade corn stalk cutter would not appeal to the average newspaper reader, but a photo and short article on its construction resulted in a $10 check from a mechanical magazine. Left—A fast lens is needed to catch action pictures of home- built devices such as this trapeze ring-bar. amateurs was not actually that in the strict sense, because for years he had been selling prints to magazines and newspapers. Yet the commercial man regarded him as such be- cause he used a small folding camera which cost perhaps $30 when new. The third man owned a camera, too, though all he had was expense, and was about fed up because, while his pictures were usually good, he failed to find any market for them. Now here's the odd part of that meeting. It came out, after much talking, that the first amateur who was selling an occasional pic- ture to magazines was getting more for his prints than was the commercial chap using an 8x10 camera. The reason was simple. A great many magazines, including the one you Modern Mechanix Newspapers and magazines are constantly seeking new апа novel pictures. Here is ‘how you can supply their wants and also be paid well. are reading, pay $3 or more for pictures with а story to tell. Often an idea, photographi- cally shown and with a short, but accurate description, having two or three pictures in- cluded, will bring a $10 check, or even more. But, lest they be overlooked in the rush for stamps and envelopes, there are a few buts and ands which are mighty important. Pic- tures of the kind that sell must convey a specific idea and must also be in sharp focus, December, 1937 In spite of the excellence of this picture, it would be hard to sell alone. Accom- panied with a story on fishing, it would have the interest needed to sell it. This picture, showing the engine which supplied power to a midget auto, proved to be the keystone of an entire set of con- struction pictures, It sold the story! Left — Two photos of this model train layout and a detailed cap- tion earned $7 for an ambitious photographer. and on glossy paper. The larger the print the better of course, but in known instances, an old Brownie, taking a 34%4x5% print that cost $4 second-hand, earned over $2,000 in less than two years for its owner. The prints averaged $3.48 each, proving that the size or quality of the camera isn’t so important as knowing what kinds of pictures will sell and to whom to send them. [Continued on page 138] 113