March FORMERLY ELECTRICAL EXPERIMENTER THE SLEEP ELIMINAT See Page 1062 etsiti:Ii;ax1ïU11A, -awe sell. tri!lif1112 Go as High as You Like No Limit to Salaries in Aviation No other industry offers the wonderful chances for big money -making that the Airplane Industry offers to ambitious men. Many more trained men will be needed to fill big paying jobs. The airplane has come to stay it will soon be a part of our everyday life. The men who get in now are the ones that will cash in big. Look at the "big fellows" in the automobile game today. They represent power and wealth because they got in early-you can do the same in Aviation and you have an advantage because you can be trained before you start. Thousands of Airplane Mechanics will be Needed The airplane industry is going forward by leaps and bounds. Transportation-passenger carrying and nail carrying lines are being opened up everywhere. This means men- Delivering Newspaper "Extras" by Airplane men-men ! Trained men only are wanted-men who know what's what. Get ready now to make big money. The industry is calling for real red-blooded fellows heed the call-HOW is the time to get started-while the industry is still in its infancy. Here Are a Few Jobs That Will Pay $50.00 to $250.00 a Week: Aeronautical Instructor Aeronautical Engineer Aeronautical Contractor Airplane Repairman Airplane Mechanician Airplane inspector s.rplane Salesman Airplane Assembler Airplane Builder Keep right on with the work you are doing now. A little of Learn at Home your spare time is all TimeyouneCotirneed. Our In Your Spare Special is simplified for home inst'uctiun and is endorsed by airplane \\\\\\\\\'\ A New Seven -Passenger Airplane manufacturers. aeronautical experts, aviators and the lead- S ing aero clubs. Any man who can read English can under - wN stand it. The Lessons are self-explanatory and are made plain (t as day with Blueprints, Diagrams, etc. Our Advisory Council / \QQe and Instructors are behind you all the time giving you every- 1rt thing you must know. The entire field of Practical Aeronautics Science of Aviation is laid right beforeA,\\your Qand eyes. You are bound to succeed withWthis training. This means for you a man'ssize job with a man's size pay. MailSend for our big Bookfree book showing ThisBig SCHOOL just what is going OFAViA77ON A New Job-The Aerial Postman of Opportunities on in the Airplane Dept. 7443 Industry. It also Coupon 3601 Michigan Ave. i shows what other Chicago F R E E men have done in For Without obligation on my this fascinating field and what you can do, too. 'part you may send me your It gives a list of some large book entitled "opportunities in manufacturers and FREE the Airplane Industry" and your dealers in airplanes and some of the jobs that SPECIAL Limitedotïer. are open to trained men. 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It will tell you system of Master Salesmen and then began to make big money. about the National Salesmen's . Training Association Salesmanship training-about the National Demonstration method experience while studying-and all about the found inspiration enough in this remarkable that gives you actual If only one man had amazing opportunities that await you in the Selling field. book to jump -to a sudden brilliant success in the Selling field- of your life to leave forever be- you This may be the one big chance into a job paying him many times his former salary-then of a routine job for a sudden, brilliant success might call it luck. But thou- hind you the low pay sands have done it. at a big salary. R E A D! Is it worth 2c. to find out? Then mail this coupon NOW. Charles Beery of Winterset, Iowa, stepped from $18 a week as Your One Chance National Salesmen's Training Association a clerk to a position making him Illinois $1,000 the very first month. to Make the Biggest Dept. 42-C, Chicago, J. P. Overstreet of Dennison, Texas, read this amazing book, Money of Your Life left a job on the Capitol Police National Salesmen's Training Association Force at a salary of less than Dept.. 42-C, Chicago, Ill., U. S. A. $1,000 a year -and in six weeks Not one of the men whose free book, earned $1,800. F. Wynn, Port- Please send me, without any obligation on my part, your names appear in the panel at and- full information about the N. S. T. A. land, Ore., an ex -service man, "Modern Salesmanship." Also a list earned $554.37 in one week. left had ever sold a thing system -of Salesmanship Training and Employment Service. Geo. W. Kearns of Oklahoma, before-not a dime's worth. showing lines of business with openings for salesmen. City found in this book a way to Yet every one of these men, jump his earnings from $60.00 a Name month to $524.00 in two weeks, through reading this book, dis- and C. W. Campbell learned from covered an amazingly easy way Street it how he could quit a clerking to jump suddenly from low pay ob on the railroad to earn City State $1,632 in thirty days. to extraordinary earnings in the Selling field. Age Occupation _,,,,,111111,,,,,,11,,,,,,,.,,,,1,,,,,111111111111111111111,,,1_ ,11111111111.11111111,,,,e,111,,,11,11111111111111a1111111,,. Vol. X March, 1923 Whole No. 119 No.11 FORMERLY ELECTRICAL EXPERIMENTER PUBLICATION OFFICE: EDITORIAL Si GENERAL OFFICES: 542 Jamaica Ave., Jamaica, N.Y. 53 Park Place, New York City Published by Experinu nter Publishing Company,-Ine. (H. Gernsback, Tres.; Publishers S. Gernsback, Treas., R. W. DeMott, Sec'y). of SCIENCE AND INVENTION, RADIO NEWS, and PRACTICAL ELECTRICS 'labile ®f C0ntenti.G SO ir March POPULAR SCIENTIFIC ARTICLES ELECTRICITY EDITORIAL 1047 THE SLEEP ELIMINATOR CHICAGO -NEW YORK -BERLIN VIA THE AIR 1049 106' By H. Gernsback By Dr. H. Becher WATER -PROOFING RAPID SCENE CHANGES "JOHANNES AND MOTH -PROOFING BY ELEC- IN KREISLER". 1051 TRICITY . By Joseph 1053 H. Kraus By Ismar Ginsberg, B.Sc., Chem.Eng THE SUBMARINE OF.TOMORROW 1053 NOVELTIES AT NEW By Graser YORK AUTO SHOW 1064 Schornstheimer, Naval Expert THE AMATEUR NEW PROCESS COLORS BLACK MAGICIAN 1069 AND WHITE MOVIE MOTOR HINTS-$50.00 FILMS . 1054 IN PRIZES MONTHLY 107o By Lewis Yeager EXPERIMENTAL ELECTRO-CHEMISTRY 1074 FISH THAT HANG UP THEIR YOUNG TO RIPEN By Raymond B. Wailes 1055 ELECTROSTATIC By Dr. Ernest Bade A.C. TO D.C. CONVERTERS 1077 RECOVERING SUNKEN TREASURES 1056 By Clyde J. Fitch HOW -TO _ HOW OLD IS THE WORLD? 1057 -MAKE -IT DEPARTMENT 1078 By Harry Van Demark LATEST PATENTS 1093 THE STAR 1058 THE ORACLE-QUESTION AND ANSWER BOX 109, 24 By H. G. Wells PATENT ADVICE-Edited by Joseph H. Kraus 1115 24 BISHOP WILKIN'S MATHEMATICAL MAGIC 1061 By T. O'Conor Sloane, Ph.D., L.L.D RADIO ARTICLES THE EVER CHANGING GULF STREAM 1061 TALKING ACROSS THE ATLANTIC THE SLEEP ELIMINATOR 10ßn 1062 UNDER -RIVER RADIOPHONE RECEPTION 1081 By H. Gernsback SECRECY IN RADIO AT LAST WATER -PROOFING AND MOTH -PROOFING 1083 BY ELEC- By A.