Popular Science Monthly 1924-07: Vol 105 Iss 1

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Read What They Say $9,000 First Year Ellis Sumner Cook, 58 Superior St., Oak Park, Ill., left a $25 a week job and last year made $9,000! $100 a Month to $100 a Week in Only 3 Months H, D. Miller, another Chicago boy, was making $100 a month as a stenographer in Ju 1922, In September, 3 months later, he was making $100 a week as a salesman. $150 to $500 a Month . W. P. Clenny of Kansas City, Mo., stepped trom a $150 a month clerkship into a selling job at $500 a month. He is making $850 a month now. $6,500 a Year M. V. Stephens of Albany, Ky., was making $25 a week. He took up this train- ing ar id now makes 5 times that much. Small Pay to Big Earnings J. H. Cash of Atlanta, Ga., exchanged his $i5 a month job for one which pays him $500 a month.

Now Sales Manager at $10,000 a Year

0. H. Malfroft of Boston, Mass.. stepped a, a $10,000 position as a SAL MANA- 4 so thorough is this training. All uccesses are due to this easy, fascin- and rapid way to master certain in- > secrets of selling.

| EMPLOYERS | are invited to write to the Employment Dept. | of the N.S. T. A. We can put you in touch | with just the men you need. No charge for = service to you or our members. Em- det: ers are also ‘es invited to request tails about the N. A. Group Plan of instruction for entire. _e forces. Synopsis

and charts sent without obligation. Cee

POPULAR SCIENCE MONTHLY I Tell You This Free Book Will Show You The Way to Amazing Salary Increases

} DEMONS TR an METIOY O i ;

Eee Manion | ; tha ;

IRST let me ask you two questions. One: Do you consider that you are as intelligent as the average mail- clerk, f farmhand, office clerk, mechanic, or bookkeeper? I ask you this because most of the men whose salaries have jumped are just ordinary, every-day sort of men. Second: If you suddenly found your- self with all the money you needed to spend, wearing the best clothes, living in the finest neighborbood, driving a good car and belonging to the best clubs—but having to make good in a job that paid $10,000 a year, would it scare you? There are men to whom $10,000 a year is so much that the idea of earning it them- selves never occurs to them. They will always be in routine jobs at low pay. Their dreams will never come true. But yours will if you will absorb what I am going to tell you. For my work in life is to take ordinary men from blindalley jobs and show them how they can quickly make more money than they ever dreamed possible. And if you will give me a chance I’m going to show you how it’s done! Now, in one quick step you can enter the field where opportunities in your favor are ten to one— the Selling field. You know that Salesmen top the list of money-makers—that the salesman is his own boss—that his work is fascinating, inte resting and highly profitable. But the thing you doubt is your own ability. All right, but you can become a first-class, money-making salesman in an amazingly easy way. Proof That Salesmen Are Made —Not ‘‘Born’’ You might laugh if I told you that in a few weeks or months you could be making good in a big way in the Selling field. Thousands before you have laughed—perhaps bitterly—at the idea, but many of these thousands are now making big money as salesmen. The story of six men who once thought salesmen were ‘‘born,’’ who did not believe they were ‘“‘cut out for selling,’’ is on this page. Thousands of men like these six—men who formerly thought salesm n were ‘“‘born,”’ are now enjoying magnificent earnings in the selling field. They were bookkeepers, mechanics, farmers, clerks —even doctors, lawyers and ministers—but in a few months after writing to the National Salesmen’s Training Association they were out in the field selling—and making more money than»they had ever helped to make in their former vocaffons. Sounds remarkable, doesn’t it? Yet there is nothing remarkable about it. Salesmanship is gov- erned by rules and laws. There is a certain way of

By J. E. GREENSLADE

I only ask that you risk two cents on the strength of my word that the con- tents of this amazing book will show you the way toa prosperity that you never dreamed possible, in a fascinating field that you never thought of entering. This book is now free. Read my offer. saying and doing thing Ss, a certain way of approach- ing a prospect to get his undivided attention, certain ways to overcome objections, batter down prejudice, overcome competition and make the prospect act. Just as you learned the alphabet, so you can learn salesmanship. And through the NATIONAL DEMONSTRATION METHOD-—an exclusive feature of N. S. T. A. Systen of Salesmanship Training—you gain actual experience’ while studying. The NATIONAL DEMONSTRATION METHOD gives you experience and knowledge that enable you to overcome sales obstacles of all descriptions easily. It is one of the many reasons why N. S. T. A. members make good salesmen right from the start. A Lifetime of Selling Experience in a Few Weeks—Then Success No matter what you are doing now, I can prove to you that you can gain years of se lling experience in a few weeks—that you can go out and success- fully sell goods—that you can make more money than you ever dreamed possible. The N.S. T. A. System of Salesmanship Training and E mploy ment Service will enable you to quic kly step into the ranks of successful salesmen—will give you a big advantage over those who tack this training. It will enable you to jump from small pay to a real man’s income. Remarkable Book, ‘‘Modern Salesmanship,’’ Sent FREE With my compliments I want to send you a most remarkable book, ‘‘Modern Salesmanship.” It ge show you how you can easily become a Master Salesman—a big money-maker—how the N.S. T. Svstem of Salesmans hip Training will give you years of selling experience in a few weeks; how our FREE Employment Service will help select and secure — se lling position when you are qualified and ready. And it will give you success stories of former. routine workers who are now earning salaries as salesmen. Mail the coupon today. It may be the turning point in your life. NATIONAL SALESMEN’S TRAINING ASSOCIATION Dept. 15-H 53 Ww. Jackson Blvd. NATIONAL SALESMEN'S Chicago Il. TRAINING ASSOCIATION

SALESMANSHIP TRAINING < Strut

National Salmen’s Training Association 53 W. Jackson Blvd., Dept. 15-H, Chicago, Ill. I simply want to see the facts. Send me free your book ‘‘Modern Salesmanship,’’ and Proof that I can become a Master Salesman. Name en ne PT =e Address ee Se ree mee ame - Cit sso in Wine enn les en cheats eam eral aoe Oe Te eeee Occupatidiia..s<«cs-<cocces =

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POPULAR SCIENCE MONTHLY

= {fuer Z~ | =~, Pas : } = e : 7 : fT

AUTOMOBILES AUTOMOBILE Parts—Used parts for most ha it factory list prices. Allen, Briscoe, Buiex, Cadillac, Chalmers, Chevrolet, Dodge, Dort, Grant, Hudson, Hup- mobile, Oakland, Over! ind, Oldsmobile, Reo,Studebaker and many others. Send list of parts wanted. Maxwell AND ACCESSORIES | any eeriat

3., 4105 Olive Street, St. Louis, Missouri ~~ PpATENTS—Write for our Guide Books and “Record of Invention Blank” before disclosing inventions. Send model or sketch of your invention for our free Examina- tion and Instructions Terms reasonable. See ad- vertisement on page 103. Victor J. Evans & Co., 189 Ninth, Washington, D. C. $1.25 BUYS a positive Headlight Tell-tale. Handy Specialty Co., Somerville, Mass SPORT Speedster and racing bodies for Fords; build to order. Build your own Bucket Seat speedster. Send $1.00 for blue prints, instructions, and life size paper gy rns, complete; Keller Auto Body Co., Inc., Dept. 24, 317 W. NO C Winkler Ave., Louisville, ar is Modern unless having the Auto-Lavatory that keeps motorists clean. Instant Service Soap and Water. Automobile Show Sensation. Special Demon- strator Price. Distributors Wanted. Emmons Manu- facturing Co., Canton, Ohio. MONE Y!—Silvering autolights, radiators, Refinishing tableware, stoves, brass beds, etc. Methods free. Write—Sprinkle-Plater, Dept. 96, Indiana. WHAT do you need? We have it Company, 3212 Brighton Road, Ky.

mirrors. Outfits, Marion,

. Gray’s Auto Parts Pittsburgh, Pennsylvania.

M. P. LAUGITLLIN—Patents-Engineer-Attorney-Spe- claliz Ing Power-Automotive Inventions. 47 West 42nd St.. ~w York. BUY a Gas Gun for $2.50 and avoid stopping on the ro'd because out of gas. Somer- ville, Mass Handy Specialty Co.,

FORD ACCESSORIES SPEEDSTER fans ad. MOTORCYCLES, BICYCLES, SUPPLIES OVERSTOCKED Must

see “Red-i-hut” page 108.

200 Used Motorcycles. be sold at once. We have Harley-Davidsons, Indians, Hendersons, Excelsiors, Clevel:nds. Prices $25.00 Up. Write for our Bargain List. ™{yerow Brothers, Dept. C 15 Berkeley St., Mass. DON'T buy a bicycle motor our catalogue and prices. Shaw Mfg. Galesburg, Kansas. USkD parts for all motorcycles cheap. Co., 1922 Westlake, Seattle, Wesh, MOTORCYCLE sidecars—Borgain prices on experi- mental and discontinued models. Write Flexible Co., 337 Water Street, Loutanville. Ohio MODELS Boston,

attachment until you get Co., Dept. 4

Schuck Cycle

AND MODEL SUPPLIES

WE make wor ang modcls tor inventors and experi- mental work, and carry aco: iplete stoc k of brass gears and moclel supplies. Se ak for catalogue. The Pierce Mocel Works, Tinley Park, Illinois MOTORS, ENGINES AND MACHINERY VEO EO if eure irplus Sale. 4HP, $8.50; IZHP, $32.50; 1 HP. S545 olt Charging Generators, S850 Complete Lightiz ants—CGenerators—Ligcht Machinery. Write for ¢ Motor Specialties Co., Crafton, Penna BIJUR Generators, brand new, 6 Volts, maximum output 22 amperes at 2000 r, p.m. Government paid $15.00 each, our price S10.0 0 General Sales Company, 1921 S. Michigan Avenue, Chicago, Illinois. CONCRIVPE Building Block Machines and Molds, Catalocue free Concrete Manufacturing Co., 307 So, Third St., St. Louis, Mo MANUFACTURING DLLs. Toois {General Manufacturing. Moucls and man turing of new inventions our specislty. Logan Machine Co., 222 8. Clinton St., Chicago, Ti ELECTRICAL y outfits : kractionsl I > Grinder and Buffer for the hor fepsir shops. _ Literature fre rie, 333BR, W . Manhattan Blvd... ‘ole 1o, oO} io AVIATION FHE American School of Aviation announce 8 a hew correspondence course in mechanics of aviation. thorough training in practical aeronautics. American School of Avi tion, Dept. 674-B, 3601 Michigan Ave., Chicago, Tllinoi WANTED TYPISTS—Earn $25-$100 weekly in spare time copy=- ing authors’ manuscripts. Write R. J. Carnes, P-1, Talla-

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Penn Lab-

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Products Co., 1696 Boston Road, New York. aking Opportunities for Popular Science’ Readers |

Another $25.00 IN PRIZES To win one of these cash prizes is easy, and every reader is invited to enter this fascinating competition. Just write a letter of not over seventy words answering this question: — What Advertisement of “Money Making Opportunities” in this issue interests you most and why? Here are the prizes we will pay for the ten best letters answering the above question: — First Prize. ...... .$10.00 Second Prize ...... 5.00 Third Prize ....... 3.00 And 7 Prizes of $1.00each ..... 7.00 First read every one of the ‘‘“Money Mak- ing Opportunity” advertisements on pages 4 to 17. Check the ones that interest you. Then read over the ones you have checked and decide on the one that interests you most. Then write ashort letter, not more than seventy words, telling us why the advertise- ment you pick interests you most. Remem- ber that ten prizes will be awarded. You have a good chance of winning one of them. Be sure to mail us your answer before July lst. The prizes will be awarded, in the order of their merit, for the letters that are most interesting and Lest expressed. The names of all the prize winners and the letters that win the first two prizes will be printed in this column in the Septem- ber issue. Address your prize letter to Contest Editor POPULAR SCIENCE MONTHLY 225 West 39th Street, New York City Last Month’s Prize Winners The First Prize of $10.00 goes to John Chirgwin, Mineral Hills, Iron River, Michigan, for his letter on the advertisement of W. Hillyer Ragsdale. Here is Mr. Chirgwin’s letter:— Dear Sir:— a Money Making Opportunities | offered through Popular Science have been of benefit to me several times, but the thing I most needed—the services offered by W. Hillyer Ragsdale—I received just when I needed it most. I can boost the advertising through your magazine, as it put me on the road to success and inde pendence. can tell the etonig all advertisements in Popular Science are K. because Popular Science is a relial ble publication. JOHN CHIRGWIN. Walter Kelly, Minonk, Illinois, wins the Second Prize for the following letter regarding the advertisement of Wells and Edwards, Chicago, Ill. Here is Mr. Kelly’s letter:— Dear Sir: Money Making Opportunities” properly and rightiully named. Youman’s Guide, found under MULAS, afforded the opportunity. The reliability of Popular Science Monthly gave me the confidence in the advertisements so that I took the time to look them over earefully which resulted in answering the above named ad. It proved to be a most profitable move, enabling me to earn, at odd times, many times over the aaa” sae nded. VALTER KELLY. The'Third Prize t.. to Norman k. nolds, Spruce Creek, Pa. The Winners of the other seven prizes are :— Martin DeVries, Tranquillity, Cal.; F. B. Clark, Tifton, Georgia; G. D. Reynolds, Altoona, Pa; Harry Frye, Tullahoma, Tenn; Jerry Zerra, Feeding Hills, Mass.; Eleanor C. Brooks, Charleston, Ww. Va.; n. <.

is very TFOR- Rey-

Rate 25 Cents a Word. Advertisements in. tended for the September issue should be received by July 5th.

RADIO AND SUPPLIES

LAMBERT'S Reaen-Out Crystals. Tue king | tise on my famous IDX crystal sets that reach out and bring in concerts 400 to 1000 miles away. Mounted, 60c each, two for $1.00. Saige ee 40c each, three for $1.00: Fixed detector, SL.i M: ailed postpaid the day 1 get your order, L eon Le ae rt, 555A South Volutsia, Wic hit a, Kansas. RADIO Generators: 500V 100 watt, $28.50. Battery Charging Generators, $8.50. High Speed Motors. Motor Generator Sets all sizes. Motor Specialties Co., Crafton, Penna.

RADIO tubes, D11l, D12, UV199, UV200, UV2014, $4.25. Duteh radio tubes, D12, D200, D2 201A, $2 50, Crystal set, 50c. Add postage. Radio Sales Co., 1168 North Kingshighway, St. Louis, Mo. WANTED—Representative in every town. Small investment. Large Profits. Write for particulars to Ray-Dee-Arteraft Instrument Co., Redlands, Calif. LOUD Speaking Crystal Set. Broadcasting heard throughout house. Easily constructed. Instructions complete 25¢e. Catalog free. Steinmetz Wireless Mfg. Co., 5810 Penn Ave., Pittsburgh, Pa SUPER radio A and B circuit batteries, which bring in long distance reception. Sold for case or on payment plan. Write for prices and details. Radio Battery Cor- poration, 501-B Industrial Bank Bldg., Flint, Mich. RECHARGE your worn out ‘B" Battery for le. Formula and Instrue —_ 50c postpaid. Monarch Sales Company, O-we-go, N. RADIO Tubes re — and exchanged; write for free circular, “How to do Away with Storage Batteries on ‘Ail Tubes.” C. F. E. Radio Tube Works, Essex Court, Newark, N. J. RADIO Sets:

Super-Heterodynes, Neutrodynes and other standard types all makes; guaranteed: 50c off list. Why pay more? Send for bulletin 245 Radio Exchange, 925 Broadway, New York. FOR THE HOME HOME weaving—looms only $9.90. Big money in weaving rugs, carpets, portieres, etc., at home from raga and waste material. Weavers are rushed with orders, Send for free loom book, it tells all about the weaving business and our wonderful $9.90 and other looms. U nion Loom Works, 482 Factory St., Boonville, New York. ~ GRANDFATHER clock works $5.00. Build your own case, instructions free; make good profits selling your friends. Clock works with chimes for old or new cases, Write for full particulars. Clock Co., Nicetown, Penn. GASOLINE Iamps, lanterns and heaters. Catalog free, Little Wonder Mfg. Co., Terre Haute, Indiana. KIDDY Kabinet—Ornamental, fascinating, useful, instructive. Actual size patterns. Instructions, 25¢,

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proved BF Metal Casting Co., 342 Last 145th Street, New York. TRADE SCHOOLS PAINT Automopdiles, Trim Automovpiles, Become 4 Certified Electrician, Auto Battery Builder, Ignition Expert on Starting and Lighting, Metal Finisher, and 4 complete course in Auto-Repairing, Bricklaying and Plastering. We fit you for a big money job. Make you an expert able to step right into a position paying $45 to $100 per week. You are paid while learning. We main- tain our own dormitories. Come to Detroit, the Auto

mobile hub; the World’s wonder city. Write today. Standard Trades School, 416 Woodward, Detroit, Mich. ADDING MACHINES FRE trinl, marvelous free adding macnine. Adds, subtracts, multiplies, divides, automatically. Work equals $350.00 machine. Price only $15.00._ Speedy, durable, handsome. Five-year guarantee. Used by largest corporations. Write today for catalog an : O, Grane

trial offer. Lightning Calculator Co., Dept. Rapids, Michiexn. FORMULAS “YOUMAN’S GUIDE” contains best 5,000 formulas and recipes for every trade, business, occupation, hou wife. Let this book make , you money. Mone} guarantee. Paper cover $1.25, Cloth $2.00. RO8t-D id. Circular, book catalog free. Wells and Edwards, De partment M, 852 George, Chicago. LABORATORY AND CHEMIC. EXPERIMENTERS. Complete supplies for the chemical laboratory. Catalogue 5c. National Scientific Supply Co., 241 Pennsylvania Avenue, Washington, D C. YOUR, chemical problem solved and working process furnished for five dollars. Write me. : Stedman Richards, Consulting Chemist, Box 2402, Boston. Mass. CHEMICAL expert furnishes manufacturing formulas with complete working directions, resulting products possessing distinct individuality and merit. Processes perfected. Alllines. No lists of worthless stock formulas but reliable individual service. Charges_ reasonable, correspondence invited. Dr. Arthur Van Heeden, 508 South Oakley Boulevard, Chicago. BE a Laboratory Expert. arn $300.00 to $500.00 monthly. Study Bacteriology, Sanitation. Interesting I:xtension, Residential Courses. Diplomas and Degrees granted. 70 Piece Urinalysis Outfit Free to Students, Write for free Prospectus to-day. Internationa Physicians and Surgeons College, Room 939, 550 Gat field Ave., Chicago. ABSOLUTELY guaranteed chemical analysis of any product so that it may be duplicated, our charge $3. is Manufacturing products formulated. ¢ al, reacted invited. Doris Chemical Laboratories, East Clevela Rox 591, Cleveland, Ohio. More Money Making Opportunities

AL SERVICE

Trcehanz, Salem, Oregon. on pages 6 to 17

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heard ictiong 3 Mfg. bring yment y Cor- lich. or le, h Saleg or free ries on Court, es and Dc off Radio ———— ney in ym rags orders, veaving Union rk. yur own | 1 your y cases, , Penn, og free, use ‘ful, B, 2s De, Kiddy process Stedman n, Mass. ee eee formulas products >rocesses formulas sonable, den, 508 500.00 teresting Degrees students. ratio! 550) Gar- nondence levela: eal ities het RR BS SSeS me: ra POPULAR SCIENCE MONTHLY Stop right here. ELECTRICITY NEE Ss YOU I Will Train You At Home This is YOUR opportunity! ness is in for a tremendous increase. Study Course in Practical Electricity I can train you for these positions. FREE BIG ELECTRICAL OUTFIT A fine outfit of Electrical Tools, Instruments, Materi- als, etc., absolutely FREE to every student. I will also send you FREE and _ fully Prepaid — Proof Lessons to show you how easily you can learn Electricity and enter this splendid profession by my new revised and original system of Training by Mail. RADIO COURSE FREE Special newly-written wire- less course worth $45.00 given away FREE. Free Use of Laboratory I have a large splendidly equipped Electrical Labora- tory where you can come at any time for special instruc- tion without charge. Several competent assistants — prac- tical engineers — are in charge. Earn Money While Learning I give you something you can use now. Early in my Home Study Course I show you how to begin making money in Electricity, and help you get started. No need to wait until the whole course is com- pleted. Hundreds of students have made several times the cost of their course in spare time while learning. Electricity is calling you, and the Electrical Busi- But it needs more trained men—at big pay. By my Home Earn $70 to $200 a Week You’ve always had a liking for Electricity and a hankering to do electrical jobs. Now is the time to develop that talent; there’s big money in it. Even if you don’t know anything at all about Electricity you can quickly grasp it by my up-to-date, practical method of teaching. You will find it intensely interesting and eed ee I've trained and started hundreds of men in the Elec- YOU CAN ALSO BE A BIG PAID Electrical Expert At the rate you Have you the specialized Have you ambition enough What are you doing to prepare yourself for a real success? are going where will you be in ten years from now? training that will put you on the road to success? to prepare for success, and get it? You have the ambition and I will give you the training, so get busy. I am offering you success and all that goes with it. Will you take it? I'll make you an ELECTRICAL EXPERT. I will train you as you should be trained. I will give you the benefit of my advice and 20 years of engineering experience and help you in every way to the biggest possible success. Valuable Book Free °);,'°3,7 come an Electrical Expert,” has started many a man 4 CHIEF ENGINEER on his way to fortune. I will send a copy free and prepaid to every person answering this advertise- COOKE ment! ‘ P , Chicago Engineering 7 Works Act Now! Good intentions never @® get you anywhere. It is action, alone, that counts. NOW IS THE a TIME TO ACT. Dept. 3-B, 2150 Lawrence Ave. CHICAGO, ILL. DEAR SIR: You may send me en- rs tirely free and fully prepaid, a copy of L. L. COOKE, Chief Engineer your book, “How to Become an_ Elec- trical Expert,’’ and particulars about your Home Study Course in Electricity. Chicago Engineering , a Name.... Works 7 7 Address 2150 LAWRENCE AVENUE 7 Dept. 3-B Chicago, U.S.A.f Aes he he eas : . State The Cooke trained man is the Bi¢-Pay man

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$2500 REWARD For the Capture of An Unknown Man WICE he had entered the St. Clair Mansion. What was he after? Who? What was in danger? Berteau, the famous detective, had warned St. Clair that the mysterious marauder would come again. And now —a noise in the passage! The creak of an opening door. A shot in the dark! A capture! Is this wounded stranger the mysterious in- truder? Whocouldtell? Yet Berteau identi- fied the man without hesitation and won the $2500 reward. How did he do it? Easy enough for the Finger Print Expert. He isthe specialist, the leader, the cream of detectives. Every day’ s paper tells of their wonderful exploits in solving mysterious crimes and convicting dangerous criminals. More Trained Men Needed The demand for traired men by governments, states, cities, detective agencies, corporations, and private bureaus is becoming greater every day. Here is a real opportunity for YOU. Can you imagine a more fascinating line of work than this? Often life and death depend on finger print evidence—and big rewards go to the expert. Many experts earn regularly from $3,000 to $10,000 per year. Learn at Home in Spare Time And now you can learn the secrets of this science at home in your spare time. Any man with common school education and average ability can become a Finger Print Detective in surprisingly short time. Free Course in Secret Service a limited time we are making a special f a Professional Finger Print Outfit, absolutely Free, and Free Course in Secret ae Intelligence. Mastery of these two lred professions will pen a brill career for } For oiter ¢ u. Write quickly for ful ‘inger Prints which expla ig in detail. Don't wait mail the cou y pired Ipon now. never see this announcement agai assume no obligation—you have to gain and nothing to lose. Write at address University of Applied Science Dept. C-136, 1920 Sunnyside Ave., Chicago, II1. UNIVERSITY OF APPLIED SCIENCE Dept. C-136, 1920 Sunnyside Ave., Chicago, IL. Gentlemen:—Without any obligation r, send me your new, fully illustrated, FI yn Finger Prints and your offer of a FI in +} Secret Service Intelligence sional Finger Print Outfit. POPULAR SCIENCE MONTHLY Money — ae cninhinsiases NAL U ON DOUBLE entry — ping saan in 60 hours; guaranteed; diploma. International Bookkeeping In- stitute, Springfield, Missouri, Desk 10. LINCOLN-JEFFERSON University. Home Study in Academy College, Theological, Law, Music, Pharmacy. Business and Graduate schools, leading to degrees. Box G, Capitol Buik ling, Chicago. USED correspor ondence courses bought and sold. Bar- gain catalogue 1000 courses free. Students’ Exchange, Dept. 3, 47 West 42d Street, New York. BOOKKEE 4 I “hig ; in a week, $1 postpaid. 1859 Walton, Ave., New York. MATHEMATICS and Drafting taught by mail. Courses in Arithmetic, Algebra, Geometry, Mensura- tion, igonometry, Logarithms, Mechanics, Mechanical Drafting, and Tool Designing. Harding School, Box H. Highland Park, Mich. VISUALIZE! Correct method of self-study. brings book. Jewett, No. 3 Englewood Ave., Massachusetts. Dukes, Dollar Brookline, ADVERTISING in 24 metropolitan dailies, 24 words, $15.00. Helpful Guide listing 1000 public: itions, 4c stamps. Wade Company, Baltimore Bldg., Chicago. SELL your real estate, stocks, business, ete.—24-word ad in 100 syndicate magazines, $2.00; 20 California Sun- ADVERTISE day papers, $15; 20 big Sunday papers covering United States, $20. Lists and other rates free. Sample syndicate magazine, 15 cents. California Advertising Service, 324 Laughlin Building, Los Angeles, California. ADVERTISING rates for magazines and weeklies free. Charles A. Lutz, Apartmént 241, York, Penn- sylvania. 24 WORDS combine newspapers, $6.00. Louis. list of 70 Sunday and weekly AdMeyer, 4112 P, Hartford, St. ADVERTISING NOVELTIES lettered Advertising-Pencils for you. direct; save entire middleman's profit. agents). Address S. Musial & Co., Yonkers, N. Y. PRINTING, ENGRAVING, MULTIGRAPHING BETTER Printing for Less Money. Write us about your printing needs, and you will save money. Ernest Fantus Company, 525 South Dearborn Street, Chicago. EMBOSSED business, personal stationery. Samples, st: =. Daniels P. Company, Pittston, Pennsylvania. 25 BOND letterheads, envelopes, billheads, cards, $1: 25 each. Combination, $4. Economic Printery. Leonia, New Jersey. 1,000 LETTERHEADS or envelopes, $3.00. GILT Buy Samples free (no 10-14 Lincoln St., Sent pre- paid. Samples free. Monitor Press, Stockham Bldg., Morrisville, Pennsylvania. 500 TWO Color Letterheads, $2.75. Samples free. Superior, 1825 Roosevelt, Indianapolis. SMALL lots our specialty. Quick service. Prices right. Budlong, Box 157, Providence. ENVELOPES or Shipping Tags at sensible prices. R. D. Elliott, 305 South Third, St. Louis. LETTERHEADS—Hammermill Bond 814 x 11, 500 $2.65 cash. Other printing, MacDonald Printery, Marietta, Ohio. COMMERCIAL Printing. Write requirements. Franklin Press, B-34, Milford, New Hampshire. 50 LINEN-FINISH noteheads, 50 envelopes beauti- ~_, printed, any address, $1.00 C’lect Stationery Co., 5 No. 43rd St., Philadelphia. GUMMED LABELS NAME and address, 500, 30c. Others rolls or loose. Stationery, 200 sheets and 100 envelopes printed $1.00. Eastern Label Co., B, Clintonville, Conn. DUPLICATING DEVICES STENCIL Duplicating Outfit—$2.00, Prints Typewriting, Handwriting, etc. Primos Specialty Co., 3-X, Primos, Pa. “MODERN” Duplicators, save Time, Labor, and Money. Gets business. Reproduces Typewritten or Penned Letters, Drawings, Lessons, Music, one Bids, $3.00, $4.00. On Approval. Notices, Specifications, Maps or anything in one‘or more colors. Prints two per minute. Special sale on days’ free trial, $2.25 up. Booklet free. J. V. Durkin-Reeves Co., Pittsburgh, Pennsylvania. OFFICE DEVICES ADDRESSING machines, multigraphs, duplicators, felders, check writers, sealers, dictating machines, at about half new cost. Pruitt, 170-Z North Wells, Chicago. TYPEWRITERS AND SUPPLIES TYPEWRITER—cost $100—will sell for $35. negie College, Rogers, Ohio. CHALK TALKS LAUGH producing program, $1.00. ‘artoonist Balda, Oshkosh, Wisconsin. LANGUAGES WORLD-ROMIC System, Masterkey to all languages: Primers, $1.94 each language; Chinese, French, Spanish. Pronunciation-Tables, 30c. Dictionaries, grammars, 1,000 languages. Languages, 8 West 40th, New York. STAMMERING ST-TUT-T-T-TERING and stammering cured at home. In structive booklet free. Walter McDonnell, 59 Poto- nac Bank Building, Washington, STAMMERING _ permanently treatment. Write Machon_ Vocal Broadway, Los Angeles, Calif. INFORMATION COMPLETE guaranteed information, any subject, $1.00. Newspaper, Magazine C lippings, $1.50. Kron- berg Clipping Bureau, 3130 Davlin Court, Chicago. COMPLETE, accurate, information on any subject, $1. Car- Circulars free. “cared. “ea - at Academy, 2: National Information Bureau, 1429P Milton St., Grand Rapids, Michigan GUARANTEED information, any subject, strictly confidential. $1.00 Doris Chemical East Cleveland, Box 591, Cleveland, Ohio. FOR SALE—MISCELLANEOUS ROCKS and minerals for sale—hundreds of varieties— price list free. P. Zodac, 157 Wells St., Peekskill, N. Y. More Money Making Opportunities on pages 4 to 17 Laboratories, Audel’s Masons & Builders Guides just ready! They give informa- a ee in handy form for Brick. Plasterers, Tile Setters p all Cement W orkers. Easy to a 4. use, showing 2067 il- B lustrations, plans and working methods. Contain best approved outlines of work and ma- B terials, including instruct- ions on howto lay out and = ge various jobs. 1100 pages of inside practical infor- mationthat willincrease yourrange of knowledge. A working companion for the journeyman; ready reference forthe boss build- er;a practical instructor for the house builder. AUDEL’S MASONS & BUILDERS GUIDES Four. helpful, pocket- size, flexiblebooks. The 2067 ictures, graphs, Ff and diagrams clearly & Ms illustrate each point. The 1100 pages are pa printed, easy to read. A_ progressive — of a a practical application to every day problems, a VOLS. COMPLETE $6 BRICK-PLASTER-CONCRETE-TILE These Guides cover fully and completely:— Brick laying, tools, materials, bonding, mor- tars, designs, setting frames, foundations. Tile setting, hollow tile, wall, roofing, setting beds, mosaic. Concrete mixing, placing, re-inforced work, stucco, waterproofing. Plastering in all its branches, wall board. Stone Masonry and Steel Construction for Masons. Estimating. FREE Save mistakes—save work—save materials— solve your problems! EXAMINATION 143 E will pay you to send in this cou- Examine AUDEL’S COUPON | Masons Guides on Free Trial. |e. 8 2 8 Fe) THEO. J AUDEL. & Co., "22 5thAve., N. Y. City Send me, postpaid, for free examination: Audel’s Masons & Builders Guides, 4 num- bers. Ifsatisfactory I will send you $1 within5S days and mail $1 monthly until $6 is paid. PURE Sen ase cueeiccs > orewrase ss pevesreesenpes PUAGNEOS 1. Gascusssusswicen ek epeeeeeeueenesleee ROGIIIANIION oan cuicicnabe aces saseesseoawces Be ReLOVEIIDY stasis sbsass ye esse ees sess osaeseee RetetenCl ee ssiascass cn pacoeuasensbees! coe uarantee to fit You for*§000 a JOBS —or It Costs You Nothing you know there is no field in the world that offers such money-mak- ing possibilities as Elec- tricity. And now thou- sands are qualifying anew quick way in spare time in their own homes. I will train you in 20 weeks, to step right into jobs paying from $50 to $150 a week. Find out how the New Shop Type training fits you in both theory and actual experience. Thou- sands are taking this short cut to bigger positions. Remarkable method guaranteed by famous Lincoln Institute of Technology. Learn all branches with- ut previous experience. Free Employment— unlimited advice—legal binding guarantee 0! satisfaction or money back. Write at once for in- formation about complete Electrical apparatus anc instruments given. Also 5 big new Free Book. No obligation. Me —— . s S$ & H Engineering Co. Affiliated with the Lincoln Mn _" Institute of Technology 4 Dept. G-16 : = —s 1422 West Monroe St. Chicago, ill. tsi , > bia ai 2 3. apie

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CRRA yori PO “‘Be industrious; keep everlastingly at it’? —that’s the way the writers of copy-book maxims would tell you to go about it. But honestly —are you fooled by that sort of talk? Why, you yourself know dozens of fellows who work just as hard as beavers, yet draw barely enough to keep them alive! Argue it any way you like, it takes something beside mere qwork to push men ahead—it takes specialized work. And to suggest, for a second, that an untrained man—no matter how hard he works—is going to be promoted to a highly specialized position—such as that of Auditor, or Traffic Manager, or Sales Executive, or Expert Correspondent, or Production Manager, or Legal Counsellor—without first eguipping himself for that position, is as absurd as to intimate that the boatman in the park who has been on the job for twenty years is likely to be chosen captain of a trans-Atlantic liner! * %* * Recognizing these facts—and surely no one can dispute them —what is the wise thing to do to change one’s situation for the better? Many a happy-go-lucky chap will tell you that all you need do is to keep your eyes open and promotion will take care of itself. It will. But, oh, how slowly! While one man is advancing by this tedious route from $25- a-week to $30-a-week to $35-a-week, another chap, not a bit smarter than he, is climbing from $15-a-week to $30-a-week to $50-a-week to $100-a-week. If you doubt it, look about you! Talk with the men still in their twenties and early thirties who are swinging $5,000 jobs! POPULAR SCIENCE MONTHLY Making Successful Men by Home-Study Training How can I make more money? How can I advance more rapidly in business? Literally millions of untrained men—yourself, perhaps, among them—are continually disturbed by those two questions. No—there’s more to advancement than merely ‘‘catching onto things.’’ TIME is the all-important factor—and that is the big reason why thousands of earncst men have refused to wait, but have turned instead to LaSalle Extension University and have shortened by many years their journey to success. That they—in so doing — have acted to their own advantage is borne out by the fact that during only three months’ time as many as 1193 members reported definite advancement which they were frank to attribute to home-study training under the LaSalle Problem Method. The total salary-increases so reported amounted to $1,248,526, az average increase per man of eighty- nine per cent. * * Your future is, of course, your own problem—and no one can solve it but yourself. If you are content to drift, you will find plenty of company though little profit. If, on the other hand, you are really in earnest when you say that you want to get ahead in business, you will find both companionship and gain in home-study training under the LaSalle Problem Method. Below this text there’s a coupon—very similar to the one which has set many, many thousands on the path to success. A_ good way to gauge your strength of purpose is—by what you do with that coupon—-NOW. LASALLE EXTENSION UNIVERSITY The Largest Business Training Institution in the World Please send me catalog and full information regarding the course and service I have marked with an X below. Also a copy of your book, ‘*Ten Years’ Promotion in One,” all without obligation to me. LaSALLE EXTENSION UNIVERSITY Dept. 783-R Chicago, Illinois i 2% ey) Busi M g t: Training for Traffic Management — Foreign and Industrial Management Efficiency: Business Eng- > On / Official, Managerial, Sales and Departmental Domestic: Training for position as Rail- Training for positions in Works Man- lish: Trainin Executive positions. zoad or —- — Manager, Rate coe. Production Control, Industrial ad Sohne } ae t, Freight Solicitor, etc. ngineering, etc. Sorrespond- Modern Salesmanship: Training for posi- — Litinias Sales Exgeutte, Salen, Eales [~]Railway Station Management: Train- []Personneltnd Fenloyment Manage: f,th Lf oach or Trainer, Sales Promotion Manager, ing for position of Station Accountant, , - lett ; . Manufacturer’s Agent, Solicitor, and all posi- Cashier and Agent, Division Agent, etc. sonnel Manager, Industrial Relations Writers tionsin retail, wholesale, or specialty selling. ‘= [Higher Accountancy: Training for posi- ae .a8 Auditor, Comptroller, Certified Financial Institutions. ublic Accountant, Cost Accountant, etc. ModernForemanshipand Production Law: Traini ° Methods: Training for positions in Shop Cc mening toe Gers LL. B. Degree. Management, such as that of Superin- [] ommercial Law: Reading, Reference tendent, General Foreman, Foreman, and Consultation Service for Business Men. Sub-Foreman, ete. Name Present Position......... Banking and Finance: Training for executive positions in Banks and Manager, Employment Manager, and Bowne: Spanish: Training for positions relating to Employee Service. position as Foreign Correspondent with Modern Busi Cor a - Spanish-speaking countries. r r . e a . and Practice: Training for position as Bare Speaking: Training in the Sales or Collection Correspondent, Sales art of forceful, effective speech, for Promotion Manager, Mail Sales Man- Ministers, Salesmen, Fraternal Leaders, ager, Secretary, etc. Politicians, Clubmen, etc. [aes Bookkeeping: Training for C. P. A. Coaching for Advanced Ac- position as Head Bookkeeper. countants. sie te Dia i ene ged dd pea dnebana nanan

Page 6

POPULAR SCIENCE MONTHL™~’ = 2 2 2 YOU TOO CAN MAKE / ADIO DRAWING ~ Bree Course ~=~| HE a: of the Radio and its increasing field of usefulness have created a keen demand for men who can de- sign and draw plans for Radio Equipment and Layout. GET IN ON THE GROUND FLOOR OF THIS PROFITABLE OCCUPATION. Here is your oppor- tunity to learn Radio Drafting Free As soon as our regular course in Mechanical Drafting has been completed the graduate is entitled to take our Radio Drafting Course free of charge. This Offer Is Made for a Limited Time Only! Therefore, do not delay and run the chance of missing this unusual offer. Rew C. Claflin Write us today for full particulars. President Other Post Graduate Courses Acn fuden fit . ° . ° = As ~ pore ah gpthcognes-y +4 which may be selected in place of Radio Drafting—and also taught Free ‘ ool « ray g 7 “ 2 under the personal instruction —are as follows— * a ‘ome 1 lin, anor at Electrical Drafting Automobile Drafting resident of this School. He Aeroplane Drafting Sheet Metal Drafting ee ee cos age earnest co Machine Drafting Shop Mathematics operation ant ¢ tens of thou sand of men ho e beer . oa He Pag Ry ott pe jent The Regular Basic Courses Are ae ene ae pose wr a MECHANICAL (Machine) DRAFTING —_—— ance . Claflin’s long year ARCHITECTURAL DRAFTING » Position | be! pidge lng dis Prete smd TOPOGRAPHIC (Map) DRAFTING ils: ane . danbt ne: ama cage eg sage Special and complete instruction in Lettering with all Te. Gian f ) courses. ington Are © [| Get You We bsiz yeu secures satistac- | Columbia School of Drafting Invited to A J oO b! ts a frequently shana which ROY C. CLAFLIN, President age ee half completed. Your ability 14th and T Streets, N. W. ee an ar S.C. Columbia School of Drafting, Dept. G-394, Washington, D. C. Without obligation, please send me your catalog showing oppor- tunities for me in Drafting and particulars of your special training. | | | | Name wn 606 wie 1s $0 88% Seer ee eee | F |” | ee | This drafting set is Free“ | with our course. rp soso LEARN AUTOMOBILE ELECTR. eek BUSINESS : “ : 5 Be independent — your rain under Yorke Burgess, recognized nationz > crs rity ind teacher of experts who not only e | rides) Earn big mon- dorse his course, but als¢ stu ly it themselves and oF Att oe Smith, West recommend it to their subordinates. Roxewdcn. Ohio, writes: nce completing your SELECT YOUR SCHOOL CAREFULLY course I have mens & $800 Do not let the size or claims of an advertisement in- per month with my gar- fluence your choice. Study the catalogs of other age and agency.”’ Oppor- schools carefully and particularly note tunities everywhere for ONE BIG DIFFERENCE—AN EXCLUSIVE FEATURE trained men. Write for of the Burgess Electrical School. ‘*Start any time, stop f .. special tuition offer on 8 ce aiken way only for wheal you cat.”” weeks term with railroad fare and board paid. Write for Catalog—a Straight from the shoulder talk Address Dept. 265. on your future in the electrical field. No mystery. No Auto, Tractor ok McSweeny “efiecica Schools } Ask About Special Offer on New Radio Course 1815 E. 24th, 9th & Walnut, BURGESS ELECTRICAL SCHOOL, Yom, Percrss, CLEVELAND, O. CINCINNATI, O. Successor to the Rahe School of Cincinnati and the 27, 746 E. 42nd S$ % c % wag aeaeeent = Cleveland Automobile School. Canadian Branch, 201 Crawford Ave., Toronto BOOKS, PERIODIUALS “LIGHTS, Colors, Tones and Nature's tiner korces,”’ including vibrations; odic auras; cold-lights; radio; in- ventions; illustrated; 270 pages, $2.00. Circulars free. Stevens Science Publishers, 242 Powell St., San Francisco. KNEIPP Sanitarium, Minneapolis, Minn. Free books on health and vigorous manhood. FREE—Send ior my Newthought, Self-culture Occult, Mystie and Scientific book literature. August Martens, Burlington, Iowa. WITHIN the Atom—by John Mills. The most fas- cinating popular book on matter and energy—third printing. Price Two Dollars. D. Van Nostrand Com- pany, Eight Warren Street, New York. SEXOLOGICAL—Psycho-analytie Literature. Latest catalog ten cents. The Book League, 47 West 42 Street, New York. TECHNICAL and Professional publications. Write Smith, Box 1032, Rockford, Ilinois. ELECTRICIANS—aid to examination for license: illustrations, diagrams, tables, ete., price $1.25. Merine and Stationary Engineers—latest answers to questions asked at examinations; profusely illustrated. Price $2.50 Steam Boilers—construction, care and operation; 170 illustrations; complete and valuable information; price $2.50. Catechism of Steam, Gas and Electric Engineering over 1000 questions and answers. Price $2.00. All books written in simple, concise English by expert authorities. Reade Pub. Co., 296 Broadway, New York. MISCELLANEOUS HOMEOPATHIC and Biochemic preparations sent postpaid to all parts of the world. Manual and booklets free. Halsey Bros. Co., 111 N. Wabash Ave., Chicago, Illinois. Established 1855. EDUCATIONAL Character—New scientific sy stem of reading people. Write H. E. Conlin, Dept. X, 21 John’s Place, Buffalo, New York. -« LOCKSMITHING, complete 500 tricks of the trade, new edition, many added features, $1.50; money back if dissatisfied. H. Routson, 3406 Aadover St., Oakland, Calif. BRITISH girls desire American correspondents Proposition 10c. Clark, 16 Cambridge St., London, S. W., England. CARPENTERS—handy men-—make combination stool, stepladder, stand, bench, writing table, service tray, drafting easel. All in one. Drawings 50 cents. Home Equipment Co., Drawer 923, Butler, Penna. MAKE interesting new friends through jolly letters Write Betty Lee, Inc., Box 820 City Hall Station, New York City. Stamp appreciated. JOIN International Postcard ¢ ‘lub. Big Membership Hobby Magazine, prospectus, 10c. ‘‘Universal,’’ 10344, Eighteenth St., Chicago. FOR MEN AND WOMEN “SEXUAL philosophy,” 12c. Clear, specific authori- tative, complete, best, satisfies. Fred B, Kaessmann Lawrence, Massachusetts. GENUINE Indian bs —_. blankets and wampum wholesale. Catalogue. Gilham, Kelseyville, Californis: MAGIC words! Secret, sure method of obtaining anything you want. Postpaid for dime. Lida Smedley, 145 Miller, Brooklyn, New York. DETECTIVES—Work home or travel. Experience unnecessary. Write, George Wagner, former Govern- ment Detective, 1968P, Broadway, New York. I WANT to send you a mighty, Cosmic influence producing joy, health and true success in your life H. Whitney, Mind-Law Practitioner. 20 Isbell St., Binghamton, N. Y. PERSONAL LONESOME—Join our club—make acquaintances everywhere. Big illustrated book with descriptions and photos, sent in plain wrapper for ten cents. Bonafide Co Dept. 43, Kansas City, Missouri. LONESOME” Hundreds everywhere want new friends. Write, enclosing stamp. Smith, Box-1167X, Denver, Colo. OF interest to lonely, single folks. (Stamp) Box &46, City Hall Station, New York. EXCHANGE interesting letters with new friends Dolly Gray Club, Box 186J Denver, Colorado. Stamp appreciated. ARE you old at forty? See our advertisement on page 92 of this issue. The Electro Thermal Company, 4035 Main St., Steubenville, Ohio. FRIENDSHIP Magazine. Classy Illustrated. 0c. PM. Box 178, New Haven, Conn. PLAYS AND ENTERTAINMENTS YOU'LL have lots of fun exchanging cheery letters in my club. Eva Moore, Box 908, Jacksonville, Florida. (Stamp.) SPORTS HUNTING AND FISHING MAI: your own fish and minnow traps. 100 minnows caught in one night. Send 25 cents for specifications and prints Easy to make. Harry Frye, Tullahoma, Tenn. BOATS AND LAUNCHES BOATS that always Go are propelled by Ford engines. Ford boat dope sent free. Hs aurry Rider, 206C Commercial Bldg., Norwalk, Conn. INVESTMENTS INVESTORS—Free Report by Registered Mail de- scribing abnormal profits from Industrial Enterprise. But you must state positively emount you might invest if suited. Kerr & Co., Suite 239 Monadnock Building, San Francisco, California. INSECTS WANTED WHY not spend Spring, Summer and Fall gathering butterflies, insects? I buy hundreds of kinds for collections. Some worth $1 to $7 each. Simple outdoor work with my instructions, pictures, price-list. Send 10 cents (not stamps) for my Illustrated Prospectus before sending butterflies. Mr. Sinclair, Dealer in Insects, Dept. 7, Ocean Park, California. FORMULAS FORMULA Catalog tree. C. A. Lutz, Apartment 24!, York, Pennsylvania. More Money Making Opportunities — on pages 4 to 17 pmoaemAown ‘es t= |

Page 7

ture, gust fas- third Com- atest reet, Vrite ense; arine tions 32.50 170 price ring, 00ks ‘ities. — — sent klets cago, land, lents. idon, ation rvice rents. tters New ‘rship D344, — thori- nann, um ornis ruining pdley, rience yvern- uence r life : St., ances s and eCo., new 167X, x 846, ‘jends stamp 1 page -_——— fers in orida. — nnows ations homa, iia Spare Time Reading Teaches Profitable Trade—Solves Problems Condensed Contents of Audel’s New Guides POPULAR SCIENCE MONTHLY Over a hundred million dollars worth of building is be- ing done every month! The biggest building boom in the history of the country. Menthat know carpentry are in great demand. The quickest way to learn carpentry and get your share of the build- ing money is by spare time reading of Audel’s Guides. Learn the fundamentals, then keep the volume you need handy as a practical Carpenters everywhere will tell, you that Audel’s New Guides are a Good Set. working guide. New Ideas -Modern Methods -Short Cuts This course ‘‘Audel’s Guides for Carpenters lers’’ consists of 4 handy volumes of over 1500 pages with thoroughly illustrated charts, diagrams, graphs, pictures with calcu- or every job from making the excava- tion to constructing the entire building. You se new Guides most complete and sive in addition to being both time- There are 3700 actual ex- amples of efficient construction work with new solutions, and Buil lations f will find th compret ly and practical. methods, ideas, plans, systems, short cuts, time and labor saving suggestions, new ways that cover the entire theory and practice of the subject illustrated by sketches and forms all specific and practical. Guides give you the short cut, professional information you want. take chances. Every day you have before you in this set the exact, practical, useful informa- tion that will help you with every job that comes up in your daily work. Audel’s No need to guess or Thousands Say Guides Are Carpenter’s Best Friend ‘Reasonable Price”’ I find the Guides very satisfactory. The knowledge in them is much great- er than I antici- pated. A very con- venient size and price is so reason- able that every car- penter should pos- sess a set. —Ralph M. Collemer, Low- ell, Mass. “Valuable for Beginners or Old Timers”’ for ready reference. The arrangement of subjects and the simple way it is explained make the books very val- uable for the begin- ner. The rules and formulas are mighty handy for the old timers.—Ross Smith, Sommers Point, N. J. **Good For Professional Carpenters’’ It is the most handy reference work that I ever came in contact with. It is the very thing that the building imechanic needs every day for reference. I wish to state fur- ther there is not a foreman or super- intendent who can afford to be with- out this valuable work. I wish you unbounded success. —George H. Wat- son, 136 Munson St., Long Island City, N. ¥. “Guides Save Hard Knocks’”’ The Guides are truly wonderful and should be in the hands of all young carpenters as well as a lot of the older heads. If I had such infor- mation 20 years ago they would have saved me many a hard knock and also sleepless nights trying to figure out the next day's work. 3 M. McJohnston, R. R. 1, Hammond, Ind. Fe **Save Money” The Guides have met with my com- plete satisfaction. Anyone expecting to build a home can well save $150 or more by using the information given in your books. W. E. Frantz, Box 77, Tuscarawas, Ohio. **Good For Amateurs” The books are surely worth more than the purchase price; especially as they serve as a guide to the non- professional like myself who is try- ing to build him- self a home at the least expense. — Otto F. Schulze, Pr O. Box 43, Westmont, III. Guide No. 1—Over 431 pages How to know the different kinds of wood. —How to use of wood. Complete d on nails and the different kinds tailed screws information How circular and band saws are handled. How to use the steel square. How to sharpen tools. How to file and set saws. How to make wood joints. Complete information regarding joints and joinery. How to build furniture. Guide No. 2—Over 455 pages —How to understand carpenter's arithmetic. How to understand geometry. —~How to understand trigonome- try. How to solve mensuration prob- lems. How to estimate the timbers. Guide No. 3—Over 255 pages—400 illustrations — How to excavate trength of foundations. How to build foundations. How to make water-proof. How to erect post foundations. How crete. to build forms for con- -How to proportion foundation footings. -How to frame houses. -How to set girders and sills. -How to frame joists. How to construct a well hole. -How to frame a studding. How to frame corner posts. —How to lay out and cut braces. Guide No. 4—Over 448 pages—400 illustrations —How to put on wood, fibre and metal shingles. How to lay gravel roofs. How to lay tin roofs. How to hang doors. How to frame windows. How to put on siding. —How to put on exterior trim. ~—How to do cornice work. —How to make a work bench. —How to use rules and scales. —How —How to PER MONTH-ENTIRE SET 1200 illustrations -How to make a mitre box. -How to make a mitre shooting board. —How to plumb and level work. the chalk line. How to lay out work. How to use How to use all of the carpenter's tools, with over 900 illustrations showing specifically how. -400 illustrations How to proportion beams. Hlow to use drawing instruments. How to read plans. How to survey. How to draw up specifications. How to estimate cost. How to build houses, barns, garages, bungalows, etc. How posts. How to frame temporary and permanent braces. How to frame girts and ribbands. How to set window frames. How to frame partitions. to distinguish various types of roofs. —How to use the settings 12, 13 and 17 on the steel square. —How to lay out mitre cuts. How to use tangents, and full detailed information covering sky lights, scaffold and hoisting. to attach lath to corner —How to build stairs. -How to lath. How to lay floors. How to put on interior trim. How to paint. first to the give aid injured. I have looked over my Audel Guides and find a wealth of informa- tio Their size makes them very handy to carry right onto the job. have put my books in my tool kit and have them FREE EXAMINATION | POCKET SIZE-FLEXIBLE COVERS yy EXAMINATION Not a cent to pay until you see the books. No obligation to pay until Qg Fs you are satisfied. Send coupon y Y , now—today and get this fine, 7 PO helpful new set for Carpenters C ne re, and Builders. After you \ 7 a So ae have looked them over 5 _«W/ a oy ws days send only $1, then yy ¥ - ~ + $1a month until $6 is /; Ceres paid—if you want to keep them, | BUILDERS MATHEMATICS DRAWING = es lee SPECIFICATIONS NTT Telos Us ESTIMATES, FOUNDATIONS

Page 8

Dire arenes Kree Course ~=~| POPULAR SCIENCE MONTHLY

HE Tats. of the Radio and its increasing field of usefulness

GET tunity to learn Radio Drafting Free been completed the graduate is entitled Drafting Course free of charge. This Offer Is Made for a Limited Time Only! have created a keen demand for men who can de- sign and draw plans for Radio Equipment and Layout. IN ON THE GROUND FLOOR OF THIS PROFITABLE OCCUPATION. Here is your oppor- As soon as our regular course in Mechanical Drafting has to take our Radio

Therefore,

Roy C. Claflin President As a student of the Caos School of Drafting vou 7 be under the personal inst —are as follows— of Roy C. Claflin, owner and Pres nt of this School. He 1 most earnest co and the tens of thou } been

etal be Ate highly adicient The Regular Basic Courses Are i : ey : “fc ¢ rom . MECHANICAL (Machine) DRAFTING Persons in ance. long years ARCHITECTURAL DRAFTING a Position of experience as a Professional TOPOGRAPHIC (Map) DRAFTING t Cc ay (replies cr iad se ae this Special and complete instruction in Lettering with all Te Wesh. k rh. courses. : ° t “7 ‘es a : ington Are Get Your We xen sccurea satisfac. Columbia Schoolof Drafting | Invited to ‘ posit on as soo as yo Ocean Park, California _

FORMULAS FORMULA Catalog tree. York, Pennsylvania More Money Making Opportunities — on pages 4 to 17

C. A. Lutz, Apartment 241,

Page 9

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POPULAR SCIENCE MONTHLY

Spare Time Reading Teaches Profitable Trade—Solves Problems Over a hundred million dollars worth of building is be- Condensed Contents of Audel’s New Guides ing done every month! The biggest building boom in the Guide No. 1—Over 431 pages—1200 illustrations : history of the country. Menthat know carpentry are in great demand. | ~~ How to know the different kinds —How to make a work bench. 2 ; ; - . on nails and screws. on Ww c “ve y working guide. Carpenters everywhere will tell, you that Audel’s How circular and band saws are SCO teh: SAE ROE See Se New Guides are a Good Set. pene te SS tn eine . T . . ej 0 mer, Low **Good For The Guides ote witha Baceygay Meta Guide No. 4—Over 448 pages—400 illustrations pie: ; meen a truly wonderful | jn your books. W. —How to put on wood, fibre and —How to build stairs. “y varpenters and should be in|}. Frantz, Box 77 metal shingles. ' aluable for It is the most ]the hands of all | Ty shaded ‘Ohis: How to lay gravel roofs —How to lath. ale handy reference | young. carpenters usa = How to lay tin roofs. —How to lay floors. ig agg a work that I ever | as well as a lot of ““Good For How to hang doors. a —How to put on interior trim. av 0ked | came in contact | the older heads. If Amateurs’’ How to frame windows. a a over my \udel | with. It isthe very | I had such infor- ‘ P How to put on siding. —How to paint. Guides and find a] thing that theJ]mation 20 years The books are —How to put on exterior trim. —How to give first aid to the wealth of informa-] building mechanic | ago they would | surely worth more ——How to do cornice work. injured. ion rheir size | needs every day | have saved me than the purchase them very | for reference. I | many a hard knock | price; especially as Ss handy Aae ay wish to state fur-]| and also sleepless | they — as a ‘ ad IRE SET right onto the job. | ther there is not a nights trying to ’ guide to the non- f Yotave put ay , FREE EXAMINATION

- y kit and have them P é 3 POCKET SIZE-FLEXIBLE COVERS) ) 11600 PAGES-3700 ILLUSTRATIONS

; i sie! — san &, om | | . & a aps | Avnet : Auvets A \y Ls ; | nee sty you sige yor \ “es apres ~ ‘ 5 ‘ books. No obligation to pay until Svs

you are satisfied. Send coupon QS now—today and get this fine, 6” OQ helpful new set for Carpenters C 74, and Builders. After you NV 7 R RY ° “< have looked them over 5 AY, © Se Ss days send only $1, then 7 — + $1a month until $6 is é paid—if you want — oe SS to keep them, Ny ly OKs 4 7 <

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POPULAR SCIENCE MONTHLY TTA! fOOST I will make yen e a lf you’re earning less than $60.00 a week, GO INTO DRAFTING! I guarantee to train you AT HOME the JOB-WAY, with actual Draft- ing Room jobs. Send for my free book, find out about the wonderful opportunities to earn big money in this easy, fascinating business. Drafting Experts are close to the Boss, are first in line for promo- tion to Executive positions. $250 to $400 a Month! Common schooling all you need! I train you by my copyrighted ‘ ‘JOR- WAY” instruction. I train you thoroughly in Drafting by giving you actual JOBS to do. No books or useless theory to waste your time. My graduates FREE! EXPERT’S Drafting Outfit | | | money. | Boston, PHOTOGRAPHY AND SUPPLIES HAVE youa camera? Write for free sample of our big magazine, showing how to make better pictures and earn American Photography, 117 Camera House, 17, Massachusetts. FILMS Developed. Special Trial Offer. Kodak film developed 5c, prints 3c each. Trial 6 x 10 Enlargement in handsome folder 40c._ Overnight Service, Roanoke Photo Finishing Co., 212 Bell Ave.,. Roanoke Virginia. 8 x 10 ENLARGEMENT from your film, colored and framed for 98e, plus 2c for insurance. Cash with order, Send for circular. Alves Photo Service, Braintree, M: ss, DEVELOP and print your own films. Complete mulas, 60c (no stamps). Results guaranteed. at Owego, N.Y. ESTABLISH yourself st home, expert; make $754 week while learning; professional mera furnished free; write quick for full information, Inte rnational Studios, Dept. 174-B, 3601 Michigan Ave., ve ago. SPECIAL! Beautiful Any size for- Studio as a photographie “Old Master’’ Enlargement, 8x10, 11x14 or 14x20. ‘Sepia or pastel’ from negative = photo, $1.00 prepaid. Finest equipped plant in a ric: Film Artists Productions. Box 417, Los Angeles, Cal. AUTHORS—MANUSCRIPTS WRITE: for newspapers and magazines. Experience unnecessary, details free. Syndicate, 971, St. Louis. WRITERS—Stories, poems, plays, etc., publication. Literary Bureau, I WANT song poems. Mawr, Chicago. PEOPLE to write articles, stories, magazine. Enclose self Box 697, Los Angeles, Calif. BIG money writing photoplays, stories, poems, songs. Send for free copy America’s greatest magazine tor writers. Tells you how to write and sell. Writer's Digest, 636 Butler Bldg., Cincinnati, Ohio. $83 FOR ideas. Photoplay plots accepted any form, revised, criticized, copyrighted, marketed. Advice free, Universal Scenario Corporation, 214 Security Bldg., Santa Monica and Western Avenue, Hollywood, California. MUSIC AND SHEET MUSIC POEMS wanted—Sell your song verses for cash. mit MSS. at once or write New Era Music Company, St. Louis, Missouri. WRITE the words for a song. We compose Our chief of staff wrote many big song-hits. your song-poem to us at once. New York Melody Corp., 419 H Romax Building, New York. A $500 cash prize is offered tor the best second verse to “T'll Be Waiting.’’ Those wishing to compete may rece ive a free copy of this song and rules of contest, by addressing Equitable Musie Corporation, 1658 Broadw: ay, NN. ¥.C. Big pay. Press Reportin g are wanted for 117, Hannibal, Missouri, Casper Nathan, J-1252 Bryn poems, addressed envelope. etc., for Guide, Sub- 117, music, Submit MUSIC Turner, works by foot power, adjustable to any size sheet; turns music forward or backward: no machined parts. Thos. Marshall, 2205 24th Ave. N., Nashville, Tenn. MOTION PICTURE BUSINESS BABY Chicks from Hi-Grade Stock—Rhode Island oa aaace atari tie Ret ae “ raw iB 8 WRITE photopliys; $50 each. Experience unneces- are SUCCESSFUL —employers ask foi Coyne- JOB-WAY”’ training sary. Details free to beginners. Producer’s Le:cue, : ' S sus ‘ k > makes you a DRAFT- 312, St. Louis. trained Draftsmen. 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Denver Optic, all calling for Drafting Experts, all waiting Rornintion. | 508 Barclay, Denver, Colorado. for you to start and finish! DOGS BEAUTIFUL registered bull pups cheap; Bulldogs, ee ee eee ee a a Draftin 501 Rockwood, Dallas, Texas. Chief Draftsman g POULTRY COYNE SCHOOL OF DRAFTING Book Dept. B-37, 1920 Sunnyside Avenue, Chicago Without oblig: in 5 iting me any way please se nd me ote book, “Drafting, the foundation of industry,” absolute yl FREE @ Mail coupon, iree. Also complete information of your rapid **Jc i 5 ® get my free book. Let me teli you Phe: —" a Le ee the rest of this story personally. Address Name i CHIEF DRAFTSMAN St. Ni , COYNE SCHOOL of DRAFTING City State f 1920 Sunnyside Ave., Dept. B-37, Chicago ELECTRICITY HANDBOOK oak Only $1 Electricity that you need to answer your many questions—to 238 ILLUSTRATIONS 414 PAGES solve your knotty problems, to cee ces ee ee ee ee eee ee ee the book on teach you new kinks, to be your memory for tables, rules, formule, and other Electrical and Mechan- ical facts, Contents: Electricity and Magnetism; Bat- teries; Circuits; Magnets; Direct and Alternating Currents; Dyna- LCs: ELECTRICAL ENGINEERS HANDBOOK INTERNATIONAL CORRESPONDENCE SCHOOLS mos and Motors; Belts; a: Box 7700-C, Scranton, Penna. roplating; rica ea- one cg Rly ety Incan- I enclose One Dollar. Please send me—post- descent Lamps; Mercury-Arc paid—the 414-page I. C. S. Electrical Hand- Rectifiers; Transformers; Insula- book. It is understood that if I am not en- tion; Electric Cars; Single and tirely satisfied I may return this book within Multiple Unit Control; Transmis- five days and you will refund my money. Sion; Weights and Measures; Chemistry; Properties of Metals. Mail the coupon to-day Whites—Black Giants—White and Black Minorci:s. Price list of thirty kinds. J. H. Miller, Waynesboro. Pa. MAIL ORDER BUSINESS $50 a week, evenings. I madeit. Mail order business booklet for stamp tells how. Sample and plan 25c. ree, 12 articles worth $3. Alps Scott, Cohoes, New York THE Mail Order Review—leading mail order journal published. pages of money-making ideas, plans, schemes, formulas. Year $1.00; sample 10c. coin. B. Oswald Pforr, Baltimore, Md. Get into mail order business the right way. information free. Valuable Pentland Service, One Thames Ave., Norwalk, Conn. FOR INVENTORS TO SELL your patent, write me; experienced handling, immediate action. Address Arthur 8S. Billings, Suite 401, Dekum Bidg., Portland, Ore. ISELL patents. Established in 1900. Charles A. Scott, 773PS, Garson Avenue, Rochester, New York. INVENTORS: We develop youl invention to practical use; make necessary drawings, models; expert engineer- ing counsel; before or after Patent; also help market yourinvention. Investigate. (No attorneys or brokers.) Caston-Guay Engineers, Washington, PATENTS—Write for Guide Books and “Record of Invention Blank.” Send model or sketch of your inven tion for our free Examination and Instructions. See advertisement on page 103. Victor J. Evans & ©0., 156 Ninth, Washington, D. UNPATENTED Ideas Can ibe Sold. I tell you how and help you make the sale. Free particulars (Copy- righted 1923). W i W. T. Greene, 811 Jenifer Building, W: »shington, DD. INVENTORS’ Educator: 900 Mechanical — Move- Taents. 50 Perpetual Motions. How to procure and sell patents. Mechanical Movements greatly assist In- ventors, suggest new ideas. Explains how to select aD attorney and avoid Patent Sharks. Price $1.50. — age negli: Albert E. Dieterich, 681 Ouray Building, Washing- ton More Money Making Opportunities on pages 4to 17 oy Satan = 17? of the big tl Woul the i who i: of the Wno s One FE SRT HTOD] a for y Pe Pf Sr ien ie butt 3 n ; me you ? 7 Sor

Page 11

— iT big earn ouse, — Size x 10 "vice, noke, l and rder, css, » for- tudio ——- iphie ional ition, Ave., nent, ve or rica! — pay. rting d for souri, Bryn , for hide, ONES, Pp for ‘iter's form, free, Santa a. —— Sub- AT, nusic, ibmit ‘orp., Tse to pceive essing OG ey ble to d; no pe. N., = PR = Z. Al oo mh

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POPULAR SCIENCE MONTHLY

There may be a fortune for you in this FREE book about Inventions Invention is the easiest way to earn a fortune. dollars for their inventors.

Little ideas have made millions of This wonderful book explains how fifteen famous in- ventors now teach you the secrets of successful invention—in your own home. OW would you like to be the inven- tor of the Gillette Safety Razor, who makes TWO AND ONE- HALF MILLION DOLLARS a r? \Vouldn’t you gladly be the inventor oi the snap fastener whose profits were so big that he paid an income tax of $29,000? Wouldn’t you willingly change places with the inventor of the President Suspenders who is now worth $5,000,000, or the inventor of the Autographic attachment for cameras who sold his patents for $300,000? One single idea—as simple as any of these— can make you independently wealthy in a Other inventors have made S nort time. thousands of dollars from such common things as the crimped hair-pin, the metal tip shoc- laces, the paper safety match, the ordinary > paper clip. These are certainly not com- ated inventions—they are so simple, in ict, that probably thousands of people thought them but only one man DID anything about he idea when it came to him. \

Ideas Worth Fortunes Every day you find ideas. naturally as other people work as bookkeepers, mechanics, doccors or farmers. Proof YOU Can Invent As a matter of fact inventors thémselves say that invention is based upon exact laws which anyone can learn. It is merely a matter of first seeing something to be fixed and then of thinking of some principle which will fix it. That is all—that is everything to invention. Brought down to its plainest definition, in- vention is merely the science of “‘fixing things.’’ And how many times a day you “‘fix things.” A leaky faucet, a rattling window, a wabbly table—you fix hundreds of things like these every year. And, though you may never have realized it, every time you ‘‘fix things,’’ you use the very definite exact principles which are the basis of Inventive Science! What Edison Says Could you ask the advice of any greater authority than Thomas A. Edison? He says: “Invention is a Science and should be taught as a profession.” And now, for the first time, you can actually learn in-

r new inventions. It may anew toy for your chil- n. The man who invented Kiddie -Kar, it is reported, ae over $5,000,000. It maybe a new kind of soap. T. Babbitt is worth mil- ns of dollars today. It can be ¢ anew kind of broom ake housework easier for mutlons of housewives. But ne matter what it is—if your Practical, if it solves a , if it satisfies a need tune may be waiting

you every science,

ideas

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15 great inventors teach step in inventive —How to develop your imagination —How to develop your —How to get the facts you need for inventions —How to keep legal rec- ords of ideas —How to use scientific principles of mechanics —How to avoid wasting on inventions. . —How to apply for a vention as a_ profession— exactly as other people are learning electricity, mechan- ics, law, medicine. The Bureau of Inventive Science offers you the first course in practical invention ever devised. It has written down the easy-to-learn prin- ciples of Inventive Science so that everybody can read them and learn to use them. It doesn’t matter who you are, or what your present work is. With no special knowledge of impractical Peths eg mechanics or science you can sr endi re /s even now you have — < eneiie learn how to invent! . br yw ideas for inventions pe ed All you need to become = ead only reason you have —How to protect your successful is this easy, fas- ._-<veloped them is because rights cinating training which will to Se ent. your own ability —How to market a patent develop your ability so it will Or, like most per- i you believe that you = not born to be an in- os that inventors are en owl io invent things as sons and

hundreds vitally important facts which EVERY successful inventor knows and uses. be worth real money. Fifteen of other famous inventors tell you the secrets of invention, e which every success- at ful inventor knows. @

Thev explain how to originate ideas, how to develop and perfect them, how to get patents. 3ut they tell even more: Thousands of in- experienced inventors have been defrauded of their rewards because they did not know how to protect their patent rights. This great course tells you everything you want to know —how to sell your invention, how to get royal- ties—how to get the most money for your New FREE Book The most interesting part of this wonderful course is that it teaches invention by actual practice right in your own home. With each lesson you are sent one practical, absorbing exercise in solving actual inventive problems which gives you an unforgetable, instinctive habit of thinking inventively—worth more that you realize. In fact, the lessons and ex- ercises are so simple, so easy to understand, so interesting that they seem more like a pleas- ant game than like instruction which can make you a successful inventor. A wonderful new book, just printed, tells you more about the Bureau of Inventive Science and its simple new course in invention. It costs nothing, so send the coupon at once. This bureau is not connected with patent attorneys or manufacturers. Its only pur- pose is to teach you the principles of practical invention used by every suc- cessful inventor. Write for the FREE .¢f BOOK now. It may show you the o way to make a fortune! @ BUREAU OF ‘4 4 INVENTIVE 67 INIANWE SCIENCE 16% 27 Winner Bul 27 Wisner ee Rochester, va 27 Wisner Bldsg., eo Rochester, eo od Ni: ¥. e 4 Name Please send me free book, ‘‘The of Invention.” your Science ¢ i ¢ Address

Page 12

POPULAR SCIENCE MONTHLY

FOR INVENTORS = vrATENT applications filed with drawing $20; ¢.cierr, and $15; strongest claims; foreign patents low. Inventox ROO Service, 11 Broadway, N. Y. min — tube CASHING In—If you have a practical, usetul eet vention to sell, write us promptly, stating wheth, ares patented. American Patents Corporation, Barris» Building, Washington, D. C. Gr LIST eo eon Needed Inventions, $1.00. Hp» han Fuller, R. F. D. No. 2, Richmond, Va. expe MR. ADVERTISER: Ask to-day for a copy of ne “Quick-Action Advertising Rate Folder.” It conta > — reallyimportant facts which will prove interesting ay lam sluable to you. It also tells “How You Can Use Popy: Ou Science Monthly Profitably.’’ You'd like to know cat wouldn't you? Manager, Classified Advertising, Popul: A Seience Monthly, 225 West 39th Street, New York. vers GET Your Own Patents. Instructions $1. Coow ret Cutting, Campbell, Calif. i ae —— \ PATENT ATTORNEYS hou PATENTS—Before disclosing an invention the j, EEO ventor should write for our blank form “Record of Inver. 5 lion.’ This should be signed, witnessed and returned | : dar us together with model or sketch and description of t wh Invention for Free Examination and Instructions Or sicte Three Books mailed free to inventors. Our illustrate Co Guide Book, ‘‘How to Obtain a Patent, contains {yj “E : instructions regarding patents. Copies of unsolicite dur letters trom manufacturers and others who are constant! } Als ae writing us regarding the purchase or leasing of merit: } asst rious patents sent upon request. See advertisement op Car pige 103. Victor J. Evans & Co., 937 Ninth, Washing. _ ron, Q. C. Ys UNPATENTED Ideas Can Be Sold. I tell you how to end help you make the sale. Free particulars (Cop; Cla righted 1923). Write W. T. Greene, 811 Jenifer Building } a Washington, D. C. 3 cen “INVENTOR’'S ADVISER” the valuable Patent boo qui with 139 mechanical movements and illustrations, sen Pri free upon request.—M. S. Labiner Patent Attorney, } = Park Row, New York. Co PATENTS, trade marks, copyrights. Prompt, per No sonal reliable service. Over 30 years’ active practice Che arn Write for terms. Book free. Address E. G. Siggers Co Box 1, N. U. Building, Washington, D. C. i The world’s biggest, most fascinating business needs you! Why slave away RN ASAN and Foreign Patents secured. Fir § kn if RET SE ORE ale ° references, reasonable rates, prompt personal servic B f =oat small pay when aa ane rac opportunities as a Cooke-trained Auto The Ramsey Co. 273 A. Bank Ste A ie re @ Expert waiting for you? Mail coupon anc PATENTS—My fees in installments. Advice book ea ; ] will tell you how I train you at home in Earn While You Learn! free. Frank Fuller, Washington, D. C. iia y Lo # your spare time for AUTO EXPERTS big- : ht 1 9. CPRE H. F. LOWENSTEIN, registered patent attorna. lat pay position. When you read that there Get my big Auto Book—it’s I REE Technical expert. 817 McLachlen Building, Washing. i are now 15 MILLION autos, trucks and —see what others have done after ton, ee ini : tractors—that car Owners are paying out only a few months of my JOB-WAY § INV ENTORS —Send for form ‘Evidence of Concep- —~ SIX THOUSAND MILLION DOLLARS training. Almost at the start I train you tion” to be signed and witnessed. Form, fee schedule, 9% kid A YEAR for up-keep you will realize here to do actual jobs and make extra money 9 Rigg ps Ph Laat and Allwine, 232 Oura é ie; is ie eenets to eet ot ee doing it. 92 out of every 100 of my Sean SEL mR 7 rr i rani Bi mand for Cooke-trained Auto Experts. s nts repor hat they ar i “=RBERT JENNER, patent attorney and mechanicl ; : rotelbe te Pk a pd 2 if nal = expert, 606 F Street, Washington, D.C. I report if patent Al N Oth T i i Lik practica » Many already obtainable and exact cost. Send for circular. oO er iraining @ making more money than the entire cost ae : ————— 2 F f “JOB-WAY” training! PATENTS—Let me assist you in obtaining your valid & Mine ! c ‘ Patent rights. Personal service. Promptness assured = George Van den Berg, Barrister Bldg., Washington, D.C ° . . . Sieneall = = = - As Directing engineer of the great Go into Business Make _LACEY P.tent-Sense. ‘‘The Book the inventor keeps.” Chicago Auto Shops | know what §$3,000t0$15,0004a year! ae aS ao —aa- 5 : R ‘ é ! -NTS—Send for booklet. ontains valuable in- 4h wrx ner ‘c pe ~~ “pepe Mighty little capital needed. The formation for inventors. Our charge for search of Patent & I GIN ty hi is COOKE OB-WAY | Office records $5.00. Prompt service, twenty years’ ex 9 S Right in your own home, I make you big thing 1S ; ; ye od J -We perience. Talbert & Talbert, 506 McGill Building, MASTER of every branch of Auto, truck, TRAINING. Rich Washington, D. C. ae “ and tractor work. I train you with prizes, big profits await FR EE y PATENTS. Booklet free. Highest references. Best 3% D JOBS—not books. I give you complete every man who has been results. Promptness assured. Watson E. Coleman, @ e and practical instruction in every detail trained to give. car- 2 BIG REPAIR OUTFITS Patent Lawyer, 644 G Street, Washington, D. C. Bic: € of Mechanical and Electrical work, Bat- owners EXPERT ser- 2 Costly testing and _ COOPERATIVE plan for commercializing _ you ftery, Ignition, Farm Power Plants, vice. I give you this repair outfits free to inventions before patenting. Booklet free. Ralph iim I Welding, Brazing, Vulcanizing, etc. training, and I alsotrain ]| every student for a Burch. Patent Lawyer, Jenifer Building, Washington 7 you how to start,and run | limitedtime. Coupon PATENTS PROCURED, trade marks registered—A s : —_ : a business of your own brings special offer. comprehensive, experienced prompt service for the protet- | M : epee) ‘ PS ee > eas k . a tion and development of your ideas. Preliminary advice ; i i jee es a + = 99 © gladly furnished without charge. Booklet of information & 8 7 ladles AutoBoo SY] Pay Raiser Book FREE! und form for disclosing idea free on request. pig Be i ( i E Mail Coupon! ’ ‘ , Owen, 44 Owen Bldg., Washington, D. C., or 2276-2 3 I : . wa ai p ] agg care rap = : Woolworth Bldg., New York. et : : young you are, how mucn or hittle INVENTORS’ Guide free on request; gives valuable 8 B. W. COOKE, Pirectinge CHICAGO AUTO SHOPS 8 ciucation you have, this training will information and advice for all who have original ideas ot } : ; : make you a successful Auto Expert. Spe- improvements. Frank Lederman, Registered Attornes 8 Dept.B26,1916 SunnysideAve.,Chicago : roa ieee and many EXTRA fea- and Engineer, 15-S Park Row, New York. y Send me FREE cho Rook ~ T ig Pc ng My tures right now. Easy terms and low cost. THE PATENTOME is free. A liberal education in a : to rane Alec sea pour encod ere of 2: FREE Coupon brings free book ‘‘The Pay-Raiser”’ patents. ge Be Son, —S established 18. fi t SK so ou : ad e h ff cessf ch. Make $3,000/00— for free books—tell how to protect yourse ote We ib MAKE $50 THE FIRST WEEK oer ate on a year. Practically no invent, ideas wanted, how we help you sell, etc. Ame - Jfascline Fame Leng semapcesin a = each eee capital required to start. Just let us Industries, Inc., 501 Kresge Bldg., Washington, I LL ty. gy ay is just begin- have few weeks your time. No pre- DISTRIG T MANAGERS WANTED acid ning. Capital is not necessary. vious experience required—every- 1 County <n pgy We help you start. Ter- thing so clear, so easy, so simple. WORLD'S fastest selling auto eal oun

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Page 13

Ce Lerrg Venton

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“—, 0. Hp Sue. Y Of the contain Sting an | ee, 1 the jp of Inver turned | On Of the # ms. Oy Ihistrate tains fy Nsolicite, onstant) of merity ement op Washing. ——__. you hor rs (Copy- Building —__——. tent book ions, sent itorney, mpt, per practice . Siggers, —e ed. Fine 1 service. nada vice book attorney, & Washing. § f Concep- schedule. 32 Ouray nechanieal t if patent your valid Ss assured ton, D.C. or keeps.” aluable in- 1 of Patent years’ e\- Building, ices. Best Coleman C. zing your iim ee. Ralph shington ristered—A the protet- nary advice nformation § Richard B or 2276-2

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———— , Company, -ade-Marks, Moderate on: Leader Pago. i iodel today No charge ooklet and a. Highest A. O'Briet, 1k Building, WV ashington, —__—_—__——— echnical —Fundreds Vrite today If, how to i Ameres on, D. C. ED eS 7~ County W., Spring

—— «er tory in_the 225 West

Money Making Opportunities AGENTS AND SALESMEN WANTED “AGENTS—Best seller; Jem Rubber Repair tor tires and tubes; supersedes vulcanization at a saving of over x00 per cent; put it on cold, it vulcanizes itself in two minutes, and is guaranteed to last the life of the tire or tube: sells to every auto owner and accessory dealer. For yorticulars how to make big money and free sample, ad- ess Amazon Rubber Co., 504 Amazon Building, Phila- delphia, Pennsylvania. GET our plan for monogramming automobiles, trucks, hand luggage and all similar articles by transfer method; experi nee unnecessary; exceptional profits. Motorists’ accessories Company, Mansfield, Ohio. $10 DAILY silvering mirrors, plating and refinishing lamps, reflectors, autos, beds, chandeliers by new method. Outfits furnished. Write Gunmetal Co., Ave. F, De- eatur, Illinois. AGENTS and distributors, sell Vanikits. The uni- versal pocket companion. No competition. Everybody needs one, fast seller. Big money. Bovee Novelty Co., 4427 Kinzie Street, Chicago. —TGENTS, both sexes, we Manufacture and control new

ho iold article. Fastseller. Big profits. Exclusive ter- rit Write now. Connolly, 123 Liberty St., New York.

SALESMEN, can make $5.00 a day selling our calen- dars, pencils, signs, advertising novelties, yardsticks,

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EASY, pleasant work for mechanics, shop men, clerks, during spare hours, will add many dollars to their salaries. Also want persons who can give full time. Big wages assured, Novelty Cutlery Company, 27 Bar Street, Canton, Ohio. $60-8200 A WEEK. Genuine Gold Letters for store windows. Easily applied. Free samples. Liberal offer to general agents. Metallic Letter Co., 434A North Clark, Chicago INSTANT Weld—Repairs largest punctures without cement or heat. Lenn’s profit one day $56. Write quick. Free sample. Territory going fast. Tourist’s Pride Mfg. Co., Desk R, Minneapolis, Minnesota. FREE Sample “Rain Shield Wiper.”” Retails $1.00 3 ¢). Sold Clear and Rainy Days. No Cloth , -No Attachment. (1) Rub keeps Windshield Clear (48) Hours. Experience Unnecessary. Nulife Corporation, Hartford, Conn. MAKE money silvering mirrors, all kinds plating, knives, spoons, auto headlights. Outfits furnished. Free Booklet. International Laboratories, Dept. 27, 311 Fifth Svenue, New York. AGENTS —100%_ profits. Fast-selling novelty for Lodge members. Emblematic Belt Co., Dept. D., Ash- land, Ohio. BIG money and fast_sales. Every owner buys gold initials for his auto. You charge $1.50, make $1.44. 10 orders daily easy. Information and samples free. World Monogram Co., Dept. 25, Newark, N. J. EVERYBODY uses extracts. Sell Duo Double strength Extracts. Complete line household necessities Big 8 da Write today. Duo Co., Dept. E66,

Attica, N. STAMPING names on emblem key checks. Sample 20e. Key check outfits, steel dies, key cases, ete. Service Sales Corporation, Shelby, Ohio. AGENTS—Clever Invention! Inkspoon makes every pena fountain pen. Fast office seller, big profit, demand increasing everywhere. Exclusive territory _ offered. Sample free. H. Marui Company, Tribune Building, New York ORANGEADE, in powder—just add cold water most delicious drink you ever tasted. Fine for home, ties, picnics, dances, etc. Start in this business—big y easily made. Send dime for ten glass package postpaid. 7 kinds, Cherry, Grape, Lemon, Strawberry, etc, 70 glosses only 50c, postpaid. Chas. S. Morrissey Co., 4417 Madison St., Chicago.

PROTECTS your home and property, the Junior Electr jurglar Alarm, attached to your Doors and ws, complete with directions for installing. Only Send $1.00 with order; balance C.O. D. Agents wanted, Wareo Alarm, Box 664, Chicago. AGENTS! At last a perfect Knife Sharpener. <A sure seller and a money-maker. Retails $1.00. 100% profit. Guaranteed a lifetime. Write, Conaway & Conaway, Dept (C) Champnign, Tl. ONLY one sale a day means $200 per month! Five sales $1,090 per month. Marvelous new adding machine. Retails $15.00. Work equals $350 machine. Adds, subtracts, multiplies, divides automatically. Speedy, accurate, durable, handsome. Five year guarantee. Offices, stores, factories, garages buy one to dozen. A fortune for live agents. Write quick for protected erritory and free trial offer. Lightning Calculator Co., Dept. P. Grand Rapids, Michigan. AGENTS make 500% profit handling auto monograms, hew pictures, window letters, transfer flags, novelty signs Catalog free. Hinton Co., Dept. 125, 1153 No. Wells, Chicago, TI.

CHEAPEST self-wringing mop made. Big Seller. 1007; pront, Easiway Company, 405 St. Paul, Palti- 1ore d.

EVERY house a sale; Fast sellers: Particulars. Hel- mers Company, Desk No. 12, Hoboken, N. J. 50 PROFIT selling name cards, penknives, sta- tionery, catalog. Wolf Labels, 1309 E. Levick Street, Philadelphia.

a BILLION, 650 million marks, real German currency rs only $1 00. Wholesale prices with order only. Atlantic 9., 1209 Beach Ave., Bronx, New York. van AKE 325 to $50 week representing Clows Famous hiladelphia Hosiery, direct from mil!—for men, women.

childrer . Every pair guaranteed. Frices that win. Free jc How to Start” tells the story. George Clows mM Ty: ipuny, Desk 24, Philadelphia, Pennsylvania Bi to $25 Daily, No Investment. Free outfit. Best Meri Largest commissions. World Raincoat Company, +S. Morris Park Ave., New York. 4 AGENTS wanted—Don’'t get pinched. Put Liteout Sn ectors on your car. Tells you when your light is out. Meee pair postpaid, $1. Exclusive territory. World ws. Co., 1522 8th St.. Des Moines, Iowa. omARE $17 day—Finest extracts, food products, cag. fee Parations, household necessities. Credit; sample Bon tee: Write for amazing offer. Perkins Products, <6, Hastings, Nebr.

ae Start you without a dollar. Soaps, extracts, per- ca toilet goods. Experience unnecessary. Carnation Dept. 21, St. Louis. More Money Making Opportunities on pages 4 to 17

: 4 Want arid s toBigPay? /Come on 2™. Get into AUTOMOTIVE GAME/ Earn $75 to $200 a Week That’s the money for you! And you can have it! Why not? The jobs are open—they’re calling for trained men to fill them—all you need to walk off with a $75 to $200 a week job is training. Get it! Here’s how:—Give us an hour a day, spare time, and we’ll quickly put you across to big success in the Automotive Game. We’ve done it for hundreds of fellows just like you—men with perhaps less education, brains and ability. These fellows are holding down big money jobs—run- ning their own business—making something out of themselves—YOU can do it too! For the sake of your dollars and cents future, send the coupon today, and find out just what we can do for you. Learn at Home From 20 Master Experts Here’s a course written not by one man, with the narrow, one-man viewpoint, but by 200f thecountry’s brainiest,most successful Automotive Experts. Fits you for a dozen big pay jobs. Shows how to start and build a successful busi- ness of yourown. Learn it allat home, in spare time, under a money back guarantee of results and satifaction. WRITEY Get Our FREE Auto Book Get the facts on this great course. Read of the success of others. Learn how you too can easily earn $3500 to $10,000 a year. Seewhy and how this course excels all others. Get our 3) special free tuition offer and full informa- tion on EXTRA FEATURES found in no other school or course. Write today for big free book. No obligation whatever. Rush the coupon or a postal today. AB/75 Automotive Division Drexel Ave. and 58th St. earn atHome toBoss the Job ARN $3500 to ¢ 10000q YEAR

the

AmericanSchool | ——

o Ad Dept.AB75 Chicago V@ Without a penny’s ex- pense or obligation please send me Free Book and all information on your Automotive Course.

eeecevesee a ecarecccenesesesee

Page 14

THE BIG PAY TRADE Ilawkins Guides give Answer plain all guides. postman. No in modern Electricity. your questions. modern Handy size. I worker can increase his pay by Highly $1.00 a Month After Free Examination Not a cent to pay POPULAR SCIENCE MONTHLY QUICKLY LEARNED IN SPARE TIME you a complete practical illustrated course Make you a master of this big-pay trade. Give you a helping hand. Fully ex- practices and short cuts. Easy to read. lexible binding. Ten volumes. Every electrical spare time reading of these endorsed, Free examination, until you see the books. Nothing to pay obligation to buy unless you are satisfied. Send Coupon now—today—and get this gre at help library and see if it is not worth $100 to you. Pay only $1 a month for ten months or return the Guide. y 10 Vols. pete Snape late Theo, Audel & Co., 72 Fifth Avenue FREE Send me for Irree Examination the 10 EXAMINATION vols. of Ha ; kins Electrical Guides. If sat- d isfactory, will send you $1 within 7 days, then $1 per month until purchase price of $10is paid. (Aude! pays postage.) Name.....- Address - SERN Se ete eile ibe els ae oboe ae 1 cL Ri Chehab e ea neeewsn 7T34 se Wants tof Play JAZZ LEARN TO PLAY ANY IN FEW MONTHS INSTRUMENT You can learn by playing Piano Mandolin actual sclections instead of Organ Drums and ot age 9 « go ises and elimin- ma ate endles 1Ours Of practice. Violin Traps A new simpliied method of Banjo Harmony and teaching reduces all music to Clarinet Composition its Flute Sight Singing | We simplest possible form. teach you in your own home by note. No numbers or ed a “‘trick stuff.’’ So simple that young and old find it easy to Cello Trombone play with amazing skill. All Guitar Saxophone intricate ‘‘mysterics’’ of music eliminated. Thousands have gener this splendid quick way. Surprise everyone and become popular, practically with your new accomplishment. FREE BOOK and Illustrated Folder offers this wonderful musical opportunity. Send for them today. You'll be astounded, thrilled, fascinated, at this easy, rapid way to become a veritable muster of your favorite instrument. Name the instrume nt you are par- ticularly interested in. Special reduced price if you write at once. U. S. SCHOOL OF MUSIC, 87 Brunswick Bids. New York City Voice and Speech Culture Automatic Finger Control overnight, Learn Cartooning At Home—tIn Your Spare Time from the school that has trained so many successtul cartoonists of today earning from $50 to $200 and more a week The Landon Picture Chart Method of teaching makes original drawing easy to learn. Send 6c in stamps for fullinformation and chart totest your ability. Also state age. THE LANDON SCHOOL 1451 National Bidg., Cleveland, O. ‘Why Good Dancers E VERYONE admires and wants qq) ~ to dance with the person who knows the latest steps. There is no need of being a wallflower! By my remarkable new easy m¢ thod, any- one can learn the newest dances at home in a few hours. Much less expensive than from a_ personal teacher. No music or partner needed, So simple even a child can learn quickly. 120,000 have learned danciny by mail Your own success is guarant teed. To prove I can quickly make you an ac- complished dancer, I will send you FREE in Pend cover, @ lesson in Fox Trot. Secret of eading, How to Gain Confidence, How to follow and to Avoid Embarrassing Mistakes. To help pay Bee cost of hancling, mailing, etc., send 2 Learn in private, surprise your ictenda: “Act now. ea good dancer DECIDE THIS QUESTION ONCE FOR ALL! ur expert vocational counselors, employing latest scientific method which eliminates ‘all guess work, will show you what occupation you are best fitted for, and B guide you step by step until you succeed. Write for free information toda : Bureau of Vocational Research, 296-D, ienkow, How York Here’ 3 the quickest way to b of your spare time for a few see Be nson jumped oS ves in six months. You, too hong now. earn money back guarantee, free tools offer. Low price an oasy Book is free. No obligation. A postal will ison Write NOW. Dept. 6178 536 South Clark Street, Chicago, Illinois ig pay work. Takes, only “§ hour a day bi m $20 to n boss Auto Job. ror rl show at home. Learnb) Sob- “Way’’ Plan. Send for ig illustrated a explaining ‘‘Job-Way’’ eroree, Tells about J. R. BAYSTON, Pres., CHICAGO AUTOMOTIVE INSTITUTE Send for our free lesson which shows how easily you can master Drafting by the Chicago *‘ Tech’? Method and LESSON if You get this pay raising training by Find out about this now. "The lesson is free 731 CHICAGO “TECH” BUILDING, - CHICAGO, BE nos Money Making Opportunities AGENTS AND SALESMEN WANTED MAKE $100 weekly in spare time. Sell what the public wants—long distance radio receiving sets. Two sales weekly pays $100 profit. No big investment, no canvassing. Sharpe of Colorado made $955 in one month, Representatives wanted at once. This plan is sweeping the country—write today before your county is gone. Ozarka, 803 Washington Blvd., Chicago. PATENTED Cigar Lighters with Glass Adve Itising Front. Also Electric Cigar Moisteners. Wonderful Sellers. No Competition. Big Steady Profits. Proof, Cuts, Sales Plan Free. Drake Mig. Co., Dept. P., Milwaukee, Wis. MAKE $8 a day selling Imported Bamboo Fountain Pen. Whirlwind seller, Free sample. Mohler, Dept. 6, 416 S. Dearborn, Chicago. NEWEST Invention! Improved Pocket Calculating Machine. Does work of expensive machine. $15.00, Agents: Big Profits! Schultheis, 1065-C Bergen Street, Brooklyn, N. Y. SELL necessities. Everybody needs and buys the “Business Guide.” Bryant cleared $800 in July. Send for sample. It’s free. Nichols Company, Box 1B, Naperville, Illinois. KARN $10 daily silvering mirrors, plating and re- finishing metal ware, headlights, chandeliers, bedsteads, Outfits furnished. F. Decie Laboratories, 1133 Broad. way, New York. GET our free sample case toilet articles, perfumes and specialties. Wonderfully profitable. La Derma Co, Dept. F, St. Louis, Missouri. AG : Big profits. letters made. Easily applied. Particulars free. Staibrite Avenue, New York. ARE you offf at forty? See our advertisement on page 92 of this issue. The Electro Thermal Company, 4035 Main St., Steubenville, Ohio. -NTS—-$75.00 Weekly Selling Nustile Guaranteed Your pay daily. You write orders, we deliver and coilect. Special monthly bonus. Sample outfit furnished. Nustile Hosiery Mills, Dept. 400, Philadel- phia, Penna. SALESMEN—Sell ‘‘Amenz” radioux shirts; guaranteed to wear one year. Very liberal commissions. Get our proposition first. Menzin Shirt Co., 479 East Tremont Ave., New York. BIG money and fast sales. Every — buys gold initials for his auto. You charge $1.50; make $1.35. Ten orders daily easy. Write for particulars and free samples. American Monogram Co., Dept. 47, East Orange, New Jersey. AGENTS: Bill Omeis, just an ordinary fellow, over $5000.00 during 1923 selling our $1.50 kitchen specialty. He is now a district manager. We are offer- ing you the same proposition—an opportunity as big as you want to make it. You can do what Omeis did. Write today, M. H. Tyler Mtg. Co., Dept. P-1. Muncie, Ind. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.” It contains some really important facts which will prove interesting and valuable to you. It also tells “‘How You Can Use Popular Science Monthly Profitably.’’ You'd like to know, wouldn’t you? Manager, Classified Advertising, Popular Science Monthly, 225 West 39th Street, New York. AGEN TS—Household necessity, sells quickly. L arge profits. Square deal. Premier Mfg. Company, Dept. 5, Detroit, Mich. $10.00 DAILY easily made selling Needle Cases; retails 25e. Send 10c for sample. Mail Order House, Wilmerding, Penna. EVERY house a sale; Fast sellers: Particulars. Hel- mers Compiny. Desk No. 12. Hoboken, POLMic?—The Wonderful Polishing Cloth that cleans all metals without liquid, paste or powder. Ap- proved by ‘Good Housckeeping” and ‘*Modern Priscilla” —sclls fast at 25c. Sample Free. F.C. Gale, 15 Edinboro t., Boston. FORMULAS, Processes, pendable, profit: a Catalog free. C. W ashington, a3; $100 WEEKL Y selling One-Minute Tire Changer to car owners, garages, tire stores, bus lines, etc. Simple— sure—spe edy—se lls on sight. Big sales records. Makes wonderful demonstration. Exclusive. We help you start. Write Dept. P, R-M Mfg. Co., 14 Riegel St. Dayton, Ohio. WONDEREUL discovery. minutes. Gallon free to agents. Paul, Minn. FREE Copy—Big Fun Magazine. wanted. Fin-Ko, 944-P Clark, Toledo, CAN you sell to colored people? Write Stratene Co., Dept. 100, 2500 Second Ave., Birmingham, Alabama. SALESMEN sell sales and order books, auto, reg. rolls and_ bill ladings. Large demand. Liberal com- mission. Wirth Sales Book Co., Dept. PS, Chicago MEN and women representatives wanted to take orders for Annie Blain flavoring extracts in every locality, wholesale and retail; new selling system; free samples to public and other unique methods. Address Annie Blain Co., New Brunswick, N. J. AGENTS—Make big money selling Horsey-Bassett Silk-Like Rubber Aprons and Specialties. Finest oD market. New styles, new colors, new selling plan. Your profits in advance. $15 a day easy. You show samples and mail us orders. We deliver and collect. Send name and address for sample apron and selling outfit, C.0.D. 75c. Become our District Manager. Address The Iforsey-Bassett Co., Inc., Dept. PS-7, Cc ristfield, Mary- land. Best and cheapest window Dime brings five samples, Company, 1115 Second made Trade-Secrets—Different, de- Thaxly Co, Charges batteries in ten Radiolite Co., St. Representatives re Two Years’ Essieeocing Course S Civil Mechanical Compact courses of essentials. mechanical drawing; also shop and field work. time and money, but strong in purpose. what is embraced and what is omitted. tary school education. Machinery. If interested, be sure to write. Electrical Richer in higher mathematics, higher science and Courses distinguished alike for Adapted to Engineers with Practical Exnerience desiring a Degree No Entrance Examination or High School Diploma Required Indispensable preliminary work provided for students with only elemen- Modern shops, Laboratories, Library, Expenses low. For catalog address TRI-STATE COLLEGE OF ENGINEERING, Box P-7, Angola, Ind, prepare for a high salaried job. increase Your Income mailunder thedirection of ourexperts. DRAFTIN The fees are moderate, the terms easy. and we send our catalog with it. EGE . CHICAGO TECHNICAL COLLEG With Diploma and Degree Chemical Planned for those short in : Apparatus and § MEN only. Sell new novelty. Sample 25 cents. How- ard Eddy, Meriden, Connecticut. EASY work, big profits selling automobile spring lubricators. Automatic Spring Oiler Co., Drawer 18, Corona, New York. THE Greatest Money Maker in years for Agents. Manufacture and sell your_own guaranteed products. Mystine Products Co., 3006 Fifteenth St., Everett. Was WANTED—Representatives in every foctory in = United States. Popular Science Monthly, 225 W 39th Street. New York. DUSTLESS Sponge Cloth. New Invention. (1) Rub—Dusts, Cleans and Polishes Automobiles. Furnr ture, Pianos, Retails 50c.—Costs 16c. Sample Nulife (H) Sponge, Hartford, Conn. —— More Money Making Opportunities on pages 4 to 17 Monogr ons Transfe! No Lice MR. ‘Quick- some re and val Popular know, 1 Popular AGE samples ticulars, — — “nd val Popular Wouldn't “clenee SY to Smooth, , big seas $100 We 12, kro M or

Page 15

tising derful Proof, ious Intain “pt. 6, lating 15.00, street, S the Send pital or experience needed. Write to- Armour Tire & Rubber Co., Desk 807-A, Dayton,

Sti 1, Pecrl Necklaces. 500% profit. Everybody wants

c E2sy to s ag Write for rock-bottom prices. Star ‘va ort Comy pany, 63 Second Avenue, New York. RETIRE in five years, selling our Super 1-2-3 Bell Gum Machine Deals. Six balls for three cents. 100% pr ae ee Purity Gum Co., 273-20th St., suWa ee

“000.00 YEARLY. State Distributor. Amazing eed Pricing System, retails $4.90 only. No re Tremendous demand!! Millen Mfg., De pt. Colon i 1 Blig.. Boston, Mass. “a into business for yourself. Make money marketing as opr ‘cialties under your own labels. We furnish veryth nd show you how. Booklet free. Nation:l Scientific Laborator ies, 224 Monroe, Richmond, Virginia. nee : Selling Teer ords. Everybody h:.s phono- Faph now y Capital or experience unnecessary oan Departme ent, 598 ¢ ‘olumbia Road, Boston. m... ATE Manager. Envelope Sealer Seals 3500 en- pes hour Amazing invention! No on Depe

_ ils $5. only. $20,000.00 yearly. Red-E Co., Dept. ) Boylston . Boston. Mess. x feeeoe NDING invention. Winterburn makes 41.4 1304- ety gsllon. Fords use kerosene. Big profit. Weeks, 19, Fondulae, Milwaukee, Wis.

“Garg ADVERTISER: Ask to-day for a copy of the lek-Action Advertising Rate Folder.” It contains and lly important faets which will prove interesting Popy uluable to you. It also tells ‘“‘How You Can Use wouldn't ee 1ce Monthly Profitably.’’ You'd like to know Science \ 0 Ms Ani ager, C lassified Advertising, al ionthly, 225 West 39th Street, New York y RUM M2 AGE Sales make $50.00 daily. Offer wonderful 609 Divie ere You. “*Wholesale Distributors,” Dept. 34 : vision Street, Chicago. er lig quick “money-maker, “Old Master” auto outfit; “Paint Car Today, Drive it Tomorrow:” smooth ipply, gives wonderful, glossy, factory-like big weg Ugh’ finish; enormous demand everywhere; $100 ai how on; exclusive territory: liberal profit; 72, Akror -~_* easy. Akron Paint Products Co., Dept.

More Money Making Opportunities on pages 4 to 17 $30.00 DAILY taking orders Beautitul guar rantec: “l

POPULAR SCIENCE MONTHLY 15 Bea BIG PAY Expert! apt ie ie OE ARES in the Great mn on — , “ Earn $250 wi . "'shops oe to $1000 per Month

Student Winding Stator Make this the most profitable and enjoyable summer of your life. Come to Chicago, the greatest summer resort city in the coun’ on beautiful Lake Michigan, and greatest electrical center in the world. We pay your railroad fare from any place in United States. See the country atourexpense. Become askilled electrical expert in great shops of Coyne. Complete Electrical Training in 3 Months Nota cores pie course—no books or useless theory right into a position paying from $50 to $250 a week. —eve in practical, You are trained on thousands Coyne trained man is trained completely. He can take na of dol Arcrpe bord pt electrical equipment. Everything from aero anywhere in the electrical world. Autoignition and door bells to power plants, You work on motors, generators, attery experts make from $3,000 to $20,000 ayear. Hun- house wiring, autos, batteries, radio, switchboards, power dreds of our graduates are making big money and you plants—everything to make you an expert ready to step - n do — same if you grasp this opportunity, eee eign ote weccee ER Radio and mer playground. Free bathing beaches, beautiful parks, — aaa and the great Municipal pier, a ball ‘ ° Auto Course parks. ia near the lake and bathing beaches. : —— a a ee wa ee FREE?! Besides paying your rail- road fare, we include FREE a course in Radio— the marvel of the age. Also, a complete course in auto, and truck and tractor electricity and storage bat- teries. Greatest outlay of auto electrical and battery equipment in the country. Earn While You Learn Our employment depart- ment helps you get a job to earn a good part of your expense. FREE Railroad Fare to Chicago Coyne Electrical School, Dept. 13.68 1300-10 W. Harrison St., Chicago, Hil, eon ow On Ow Dear Sir:—Please send me free your big catalog and full particulars of your — offer of free This is the eatest offer ever made by a school and it is for a lim- railroad fare and 2 extra courses ited time. Don’t delay a single minute. Send the coupon in right away for our big firee catalogue and full particulars of this won- derful offer. Act now! We pay your raitroad fare. Coyne Electrical School 1300-10 W. Harrison St., Dept. 13-6B, Chicago, Ill. LEARN ENGINEERING Great Demand for Practical-Technical Engineers. sig Learn

Name Address.

Salaries. Wonderful Opportunities. Thousands of our graduates holding responsible high- salaried positions. Flestrical and Mechanical Enamecrine, Simple and con, | AYN $7O to $200 a Week

densed Method. Faculty of Trained Experts. New Become a recognized radio expert. Trained men in urgent demand Building. Extensively Equipped Laboratories and Shops. | 38 brondcasting ang ie onsrsprb fay positions now open. No Department of Architecture. Structural and Mechanical Cagisun tealntae necessary. We train you in theory yds 4 Mies Drafting. Degrees Awarded. Positions Secured. Day and eceiving set parts and diagrams for practical work at home furnished Night Sessions. Summer School Now Going on. 22nd free. First school to teach radio by mail. EF :tablished 1914 Thousands Year Begins Sept. 17. Write for Catalog A of successful sraguates. Get facts and details of special tuition offer : . aps . from Free Book **Ric h R-wards in Radio.’" Write today. State age, FINLAY ENGINEERING COLLEGE, Kansas City, Mo. lati i Radio | Dept. 12GA, Washington, D.C.

WRITING idays—no experience needed. We establish you sin y our own shop, ‘ : any locality, worth $60 weekly, up; furnish all material and plan to secure order % a f-om local merchants to do righ home, evenings, if cosired. Get into t thin f fasc earns. eusily Ow al s A learned, profitable business. Cost low—terms easv. Illustrated matter and terms FREE EMPIRE INSTITUTE, 1476 Broadway, New York

Page 16

$20°°aWeek This Man Wouldn’t Stay Down He was putting in long hours at unskilled work. His small pay scarcely lasted from week to week. He saw other men promoted. Then he learned the reason. They had special training. He made up his mind to get that kind of training. He sent to Scranton a coupon like the one below. That was his first step upward. The reward was ing he was made Foreman. is Superintendent. It just shows what a man with ambition can do! What about you! You don’t have to stay down. You can climb to the position you want in the work you like best. The way to do it is easy—with- out obligating yourself in any way, mark and mail this coupon. not long com- an increase in salary. Then Now he \ ~ INTERNATIONAL CORRESPONDENCE SCHOOLS _ Box 7696-C, Seranton, Penna. Without cost or obligation on my part, please tell me how I can qualify for the position or in the subject before which I have marked an X BUSINESS TRAINING COURSES (Business Management (J Salesmanship (JIndustrial Management } Advertising {_})Personnel Organization LJ Better Letters {} Traffic Management (J Show Card Lettering QO Business Law _} Stenography and Typing {Banking and Banking Law } Business English [J Accountancy (including C.P.A.) (J Civil Service Oo Nicholson Cost Accounting [} Railway Mail Clerk atk wokkeeping [| Common School Subjects Private Secretary [} High School Subjects Spanish O French Lj Llustrating TECHNICAL AND INDUSTRIAL COURSES Electrical Engineering Ty Architect Electric Lighting [j Architects’ Blue Prints () Mechanical Engineer Contractor and Builder {) Mechanical Draftsman >] Architectural Draftsman () Machine Shop Practice + Concrete Builder C)Railroad Positions [] Structural Engineer Gas Engine Operating [] Chemistry [1 Pharmacy (Civil Engineer [] Automobile Work Surveying and Mapping (] Airplane Engines Metallurgy 0) Mining C] Agriculture and Poultry Steam Engineering O Radio [FF Mathematics Name........ esos — Street 3-G-24 I cantrachemabhntecddaunstucastbienn+:enenrs seecineesostmebsonbensoeensineen | oe ... State 2 SD i ctticsinkcnishecbusewnccenes Persons residing in Canada should send ‘this coupon ‘to the International Correspondence Schools Canadian, Montreal, Canada Limited, POPULAR SCIENCE MONTHLY HELP WANTED Excellent opportunity to earn big money, travel, thousands of dollars offered in rewards. Established 1909. Particulars free. Write to C. T. Lud- wig, 424 Westover Bldg., Kansas City, Mo. SILVERING Mirrors, French plate. immense profits. Plans free. celsior Springs, Mo. OUR genuine gold window sign letters are an excellent money-making proposition for handy men. Slann Sign System, East Bethune Avenue, Detroit, Michigan. EMPLOYMENT in South America. We furnish classified lists of 350 employers for $1. South America Information Bureau, Portland, Oregon. ALL men, women, boys, girls, 17 to 65, willing to accept Government Positions, $117-$250, traveling or station- ary, write Mr. Ozment, 295, St. Louis, Mo., immediately. PARN $10.00 to $35.00 weekly mailing circulars at BE a detective Easily learned; Wear Mirror Works, Ex- home. Outfit and instructions 25 cents. Jamorris, 2305 Gratz, Philadelphia, Pa. WANTED—Representatives in every factory in the United States. Popular Science Monthly, 225 West 39th Street, New York. DETECTIVES needed everywhere; cities, towns. Particulars free. Write National Detective System, 188 East 79th, New York. FIREMEN, Brakemen, Baggagemen, Sleeping car, train porters (colored). $140-$200. Experience un- necessary. 838 Railway Bureau, East St. Louis, Il. DETECTIVES earn big money. Excellent oppor- tunity. Travel. Fascinating work. Experience’ un- necessary. Particulars free. Write American Detective System, 1968 Broadway, New York. WRITE photoplay:; $50 each. Experience’ un- necessary; details free to beginners. Producers’ League, 312, St. Louis SALESMEN, we pay larger commission than any other brush house in the country to men selling our line of Sanitary Twisted in Wire Brushes. Sanitary Wire Grip Brush Co., 15 Mercer St., New York. MAN Wanted by largest concern of its kind. full time. Experience unnecessary. Our men getting up to $200.00 weekly. Lowest prices. Red Seal Coal Company, 360 Coal Exchange Building, Chicago. STOP Daily Grind. Part or Your town needs plater operator. There's money silvering mirrors, headlights, radiators, bumpers, stoves, tableware. Reliable outfits furnished. Here's help Free. Sprinkle Plater, Dept. 98, Marion, Ind. MEN—Experience unnecessary; meke secret investigations; reports; salaries; expenses. Write Ameri- can Foreign Detective Agency, 321, St. Louis, Mo. RAILWAY Postal Clerks—Start $133 month. roud pass: expenses paid; questions free. Institute, N-2, Columbus, Ohio. travel; Rail- Columbus Money Making Opportunities | Every Engineer, Mechanic and Electrical Worker will welcome this new master set. It will answer your baton vic it will help you with your daily work.—A sure source of advancement and higher pay. Complete up-to-date information that is thoroughly and easily explained on every branch of modern engineering and electrical practice. ’ AUDEL’S ENGINEERS & MECHANICS GUIDES 4750 PAGES $1 A MONTH 8754 ILLUSTRATIONS $12 COMPLETE These Guides tell you all about— Theory, Practice and Operation of ALL St UNIFLOW and POPPET VALVE ENGINES, and LOCOMO- BILES. Locomotive-Marine Engines; Turbines: Rotary Engines --the Indic ator -- me aes -- PRACTICAL MANAGE MENT. GAS, GAS EN ES--Aeroplanes and Aviation--HOW TO SELECT AN ENGINE. STEAM ENGINE gles and formulee. Steam Boilers; Heat-Combustion; Fuel and Flue Gas Analysis- C02 Recorders-Construction of all t pes of Boilers,--Mechanica Stockers--Oil Burners--Se tting--Chim s--Mechanica a) rant --HOW TO SELECT A BOILER--ROT ER DESIG sed on S.M.E. BOILER CODE--OPERATION FIRING. iss Fit- tinge --Heating and Ventilation--Refrigeration--Cooling Towers --Condensers--Distilling Apparatus--Plevators--Cranes--Ropes and Cables--Splicing--Practical Electrical Engineering as an aid for engineers and electricians in obtaining a license--re ady reference index, covering entire field of Modern Electricity. SHIPPED TO YOU FREE team Engines; RAILWAY Mail, Postoffice Clerks, Carriers, Customs, and many other positions open,—$1400-$2300 yearly. Write tolay for 36 page booklet showing how to obtain one of these desirable Jife positions. Chicago Civil Service College, T-70 Kesner Building, Chicago. ARE you old at forty? See our advertisement on page 92 of this issue. The Electro Thermal Company, 4035 Main St., Steubenville. Ohio. BUSINESS OPPORTUNITIFS BECOME A Foot Correctionist. A New Profession, not medical nor chiropody. All the trade you can attend to; many are making $3000 to $10,000 yearly, easy terms for training by mail, no further capital needed or goods to buy, no agency or soliciting. Address Stephenson Labora- tory, 10 Back Bay, Boston, Mass. CAPITAL furnished to old established firms who desire to expand their business, and arrangements made to secure funds for promotional enterprises and where true worth can be established. T ‘he system which we have for providing funds is in no way a hardship on the recipient, and we can give immediate action. Room 603, No. 50 Pine St., New York FREE plan—start mail order business. H. J. Teeple, Decatur, Indiana. USED correspondence courses sold, rented and ex- changed. List free. (Courses bought.) Lee Mountain, Pisgah, Alabama. FREE Book. Operate little Mail Order Business, home evenings Pier 773, Cortlandt St., N.Y. START your own business, remunerative, interesting; little capital. Dept. R, Paul Learn ie ge trading. Kaye. 149 Broadway. N. Y. I MADE $30 a —— home. French breadmaking. 15 years’ experience; Free booklet tells. Ashbrook, E. 67, Marengo, O. HOW O. T. H. 8. B. R. Co., Oblong, Il. $120 STARTS profitable mail order agency business; no soliciting: can make $40 weekly: part time required: everything furnished: bank reference furnished; full sample and book. Mervel Co., 6002 Market, Phila- delphia, Pa. STOP 1} plodding! Be successful. Operate a tire repair shop. Make big profits in any locality. We teach you and furnish complete equipments, $100 up. Book of Opportu- nity iree. Haywood’'s, 1306 South Oakley Avenue, Chicago. NMI{AKE Money! 120 Plans Free! C- Muskegon, Michigan. $10,000 A Year With Your Own Business is yours for the asking if you have the ambition to Boss yourself, the courage to Make success yours, we can put you “on top” of the heap. This is no agents proposition but a bona-fide opportunity to establish yourself in your own business regardless of the amount of capital you want to inves Write us today ve? Free booklet. Progressive Business Builde rs, Dept. A, Passaic, New Jersey. INCORPORATE; oa private property; perpetual charters immediately; cheapest: best; information free. Incorporating Bureau, Philip Lawrence, Huron, South Dakota. INCH Display made $110.00 in 2!4 hours. 10c. Wolverine Bureau, Advertisement 166 Magazines Thrice $15. Year $50. Wood's Popular Service, Atlantic City. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.’’ It contains some really important facts which will prove interesting and valuable to you. It also tells ‘‘How You Can Use Popular Science Monthly Profitably.’’ You'd like to know, wouldn't you? Manager, Classified Advertising, Popular Science Monthly, 225 West 39th Street, New York. More Money Making Opportunities on pages 4 to 17 Not a cert to pay until Sonieee see the books. pay unless you are satisfied. this new master set for engineers. No obligation to Send coupon now--today and get Pay only $1 a month, Ore. AUDEL & CO., 2 Fifth Ave., N.Y. Please imi te me for r apetcee FOR ENGINEERS & MECHANIC S, Ship at once prepaid, the 8 numbers. If satisfac- tory, lagree tosend you $1 within 7 days and to mail you $1 monthly until $12 is paid. Sig nature Occupation Employed by Residence Reference 7 Teach By Mail I can make a good penman of you at your home during spare time, no matter where you live or how poorly you now write. 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The ManWho is Astoundin America! What is the mysterious power wielded by this man—a power he also shows others how to use? What is this new method which has started thousands of despairing persons on the road to health, happiness and prosperity? HOUSANDS upon thou- sands have been turned away from the great theatres and auditoriums in Chicago, San Francisco,Seattle, Denver, Boston, and _practi- cally every great city in Amer- ica where Dr. Bush has been lecturing! Those who were ill have been shown how to become well and strong by a method to which other mental science move- ments were as the first step in a far-reaching stairway. The worried and the diences had been taught POPULAR SCIENCE MONTHLY to use this wonderful power. Reports so amaz- ing that they were in- stantly investigated by Newspapers, and_ Socie- ties for Psychological Research —and found absolutely true. 3y your method of visual- ization I secured the funds to build my home,” writes one of Dr. Bush’s Chicago listeners. Mrs. Mary Roberts of Denver writes, “My salary was in- creased 40% in one week by following your nervous have been shown how to rise above their mental and nervous trou- bles in a_ single evening and how to attack and solve their problems un- hampered by des- pair. conscious Vibration Poverty a Overcome It An Astounding New Power True ful as it is to have the secret of men- Universe, Partial List of | Contents || powers of Psycho-Analysis and the Sub- | Worst Enemy What Is Love and How to Keep | It How to Develop Personality How to Be Popular How to Be Beautiful Through Mysterious Force How to Win Suc- cess—How to Kill Worry— Conquer Illness Disease—How to How to Double Your Efficiency VISUALIZATION — How to Make Your Dreams Come - How to Use Suggestion for But as wonder- gaa Success and Happi- The Greatest Just Lately Dis- covered and How to Use It What the World Owes You and | How to Get It —— psychological method and my sales- manship were How to Have Amazing Memory | DOUBLED.” How to Destroy Fear—Man’s | | His Teachings | Now in | Book Form | Dr. Bush’s sole idea in giving these lectures is the same that actuated him in his earlier days. Then as an earnest and brilliant young Law in the tal and physical health — there is a still greater force at work. This force can be harnessed to bring us the material things —money, power, — influence, no matter what it is. Dr. Bush has harnessed this force, and has proved that he can show others how to use this power. Long before the lectures were over, reports began to come in showing how quickly his au- minister of the Gospel he refused honors and financial returns to apply his efforts where they would do good to the greatest number. His lectures are given to teach this new force to everyone. And to reach more people he has incorporated his lectures in an absorbingly in teres sting book, ‘“Ap- plied Psychology,” which will be sent on FREE TRIAL to any earnest seeker. Luther Burbank says, “Ap- plied Psychology appears to me the most practical and useful work which has been published on these and similar subjects.” - — - DR. DAVID V. BUSH Editor of ‘‘Mind Power Plus’’ Are you nervous or depressed? Do you feel old? Have you lost your grip? Have you a worrying disposi- tion? Have you a personality that fails to attract others? Are you timid? Are you misunderstood? Do you lack the aggressiveness necessary to bring you position and power? Are you in ill-health? Have you any chronic disease? Is anyone in your family or among your friends so affected? Are your children wilful and disobedient? Examine It Free Mail the coupon. This book will be sent at once. Read it five days. Practice this new force yourself. If you find it the most inspiring, the most valuable means to obtain health, wealth and happy ness, send us only $3.50—which you will realize pays only the cost of printing, advertis- ingand distributing the 540 page book. Otherwise return the book within five days and you will not owe a penny. But begin to enjoy the bene- fit of this new force atonce. Mail the coupon today. APPLIED PsvcHouom® AND ENTIFIC FING DAVID V. BUSH, Publisher Dept. 97, 225 No. Michigan Blvd., Chicago, ih DAVID V. BUSH, Publisher Dept. 97, 225 N. Michigan Blvd., Chicago, Ill. Please send me a copy of ‘ ‘Applied Psychology and Scientific Living’’ for approval. I agree to re ut $3.50 or re-mail the book in five days. Il PR ¢¥ ] worth chase: article Asan tute g radio Mont! you t for ra Wh labors it me user, | deterr mecha all sol give t! TI tivity oran adjust put, a anteny ting s¢ nal Str is mes outpu' actual Castin,

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igo, Ill POPULAR SCIENCE MONTHLY a ee a PS Tests of a Radio Set in Popular Science Institute of Standards Laboratory where, HES Le ST by means of a miniature transmitter, the action of a set can be accurately measured PROTECTION FOR YOU IN YOUR RADIO PURCHASES By COLLINS P. BLISS, M.A. Director of the Popular Science Instituie of Standards HE newly established Popular Science Institute of Standards offers you trust- worthy and impartial guidance in your pur- chases of radio equipment, tools and other articlesofa technical or semi-technical nature. Asan important part of its service the Insti- tute guarantees to you the reliability of every radio product advertised in Popular Science Monthly. Engineers of the Institute protect you thoroughly by exhaustive tests which for radio sets consider: 1. The external appearance 2. Workmanship . Sensitivity . Selectivity . Amount of amplification 6. Ware-length range 7. Quality of reproduction . Operating characteristics Ct mm cot ‘ ¢ € When we first receive a set for test in our laboratories we examine it to determine that it meets the requirements of the average user, Each piece of apparatus is inspected to determine that it is constructed properly mechanically, and is built substantially ; that all soldering is perfectly done and that it will give the maximum electrical efficiency. _ Then laboratory tests are made. Sensi- tivity is determined by means of an oscillator ora miniature transmitter, which has been adjusted previously for a predetermined out- pul, and then started and placed so that the antennae coils of the receiving and transmit- ling sets are in a coupling position. The sig- nal strength at the end of the detector tube 'Stheasured. By varying the transmitter output of the oscillator we can imitate the actual conditions found with stations broad- casting at different power outputs. By vary- ing the coupling we can approximate the strength to be received at different distances. Analysis of readings thus obtained gives a determination of the sensitivity and signal strength locally and for the distance. EXT is a test for selectivity. With the same set-up as in determining sensi- tivity, we can tune in on the oscillator which has been started with a predetermined coup- ling and transmitter output. The signal cur- rent is measured on the detector. Then the transmitter is detuned until the signal cur- rent is reduced to about one-half. By use of formulas, selectivity of the set is determined in terms of the frequency change. Thus the less the change is required in detuning the transmitter, the more selective is the set. @ 7 POPULAR SCIENCE Monthly Guarantee The above seal on an advertisement indicates that the products referred to have been approved after test by the Popular Science Institute of Stan- dards. Popular Science Monthly guaran- tees every article of merchandise advertised in its columns. Readers who buy products advertised in Pop- ular Science Monthly may expect that these products will give absolute satis- faction under normal and proper use. Our readers in buying these prod- ucts are guaranteed this satisfaction by Popular Science Monthly. THE PUBLISHERS. af The amount of amplification is determined by using the same set-up but with modulated audio-frequency. The amount of amplifica- tion is measured by comparing the signal strength with the amplifier and the signal strength using the detector tube only. In this way we can determine whether or not a set gives a sufficient amount of amplifica- tion. After this a test of wave-length range is made. A measure of the range of the set as a receiver, its maximum and minimum range of wave length, is made. To be an efficient receiver, it must, of course, be able to cover the usual wave lengths used by the different broadcasting stations. The quality of reproduction is another important factor. The set is operated under average conditions and a determination of the quality of reproduction is made. The final test of the series is that of operating characteristics. A determination of the ease of tuning is made. Then, too, there must be a sufficient independence of tuning. It must be possible to tune in accurately; for this you require fine control. Finally, the set must remain put after it is adjusted. RADIO set must pass the rigid tests outlined above, to receive the Popular Science Institute of Standards approval. Readers are urged to make full use of the service of the Popular Science Institute of Standards, as through the careful testing of a staff of competent engineers the Popular Science Institute of Standards assures every reader that the Radio Products displayed in our columns are of good value and will under normal and proper use give absolute satis- faction. Test of radio apparatus is only one of the functions of the Popular Science Institute of Standards. In the next issue of Popular Science Monthly we will tell how we protect you in your purchases of tools.

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POPULAR SCIENCE MONTHLY EB DUAL ELDS “The Sage attends to the innerand not to the outer.” Lao Tru LOSE inspection of many receivers reveals ia b 4 ) but one large shield to prevent body- Tie ae big a ais capacity effects. Asa result of research, each receiver is not misled, he tuning control on a GREBE Receiver has its looks inside the cabinet. : : ; ‘ : own aluminum shield of special size and shape. Y eater” 4A This is just one of many details of crafts- manship which make for the high efficiency of GREBE Receivers. oe , Va Ask vour Dealer or write us. A. H. GREBE & CO., Ine. ahs Micouedscetcis Van Wyck Blvd. Richmond Hill, N. Y. Receivers are licensed Western Branch: 451 East 3rd Street, Los Angeles, Cal. under Armstrong U.S. Pat. No. 1,113,149

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PQPULAR SCIENC: MONTHLY SUMNER N. BLOSSOM, Editor July, 1924 Through outdoor loud- speakers, indicated by the arrows, throngs outside the national Capitol heard Presi- dent Coolidge deliver the first message to Congress ever broad- cast by radio. By the same magic of radio millions of American voters this summer will hear the campaign speeches of the presidential candidates Radio’s Part in Politics RESIDENTIAL campaign year 1924 brings with it a brand-new puzzle for the politician. The puzzle is the radio fan. Politics is largely a matter of publicity. Since the 1920 campaign, radio broadcasting has developed into one of the greatest medi- ums of publicity in the land. Hence the politician’s concern. When those fellow Ohio editors—and Publicity experts—Warren G. Harding and James M. Cox ran against each other for the presidency, there were but 15,000 sets in the country. That figure is the timate of the Department of Com- merce radio experts. Today, Secretary Hoover estimates that there are no less than 5,000,000 radio receiving sets in Tegular use. Since—through loud- Speakers and extra head sets—each re- “lver probably averages at least two isteners, it is probable that some 10,- 000,000 people hear what the radio waves are carrying each day. : To a political spellbinder, eager to sell By Edward G. Lowry Mr. Lowry is one of America’s fore- most political writers. Through his close personal contact with the leaders of both the Republican and Democratic organizations, he is able to present here the first com- prehensive estimate of the tre- mendous part radio will play in electing our next President. his wares, that is an audience such as no man before, even in his wildest dreams, ever hoped to reach. Probably the most ambitious spellbinder this country has ever known is James M. Cox. His cam- paign in 1920 was a marvel to foe and friend alike. During the last three months of his campaign, Cox traveled more than 10,000 miles in his special car, talking on an average of 10 times daily to audiences ranging from mere handfuls of people to the 30,000 who assembled to hear him on notification day at the Dayton Fair Gounds. Cox was able to achieve this almost superhuman task because he was physi- cally stronger than nine out of 10 men of his age; and he was considerably younger than the average presidential cam- paigner. Also, to keep himself fit, he carried with him his own cook and masseur. OW many people heard Mr. Cox? There is no way to ascertain the exact number, but newspaper corre- spondents who traveled with him once figured that he may have made his voice heard to 1,500,000 at the miost. A more conservative estimate would be 1,000,000, or but one-tenth the number the Democratic candidate in 1924 can reach in one evening from his comfortable front porch, if he can arrange for an adequate chain of broadcasting stations to carry his message to the radio fans of the whole country. Indeed, through the magic of radio, either of this year’s candidates, if his line is connected with such a chain of 21

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POPULAR SCIENCE MONTHLY The corner soapbox—1924 edition. This powerful radio receiver with loud- speaker, mounted on a motor truck, is designed to carry the voice of a distant campaign orator to the street-corner crowds. It may play an important part in this year’s presidential campaign broadeasting stations, can talk through his own home or office telephone to an audience greater possibly than the total number of people who heard the voices of every presidential candidate since the time of Lincoln! Certainly this is a phase of present-day campaigning that can not be overlooked. IF COURSE, there is the view that Cox in 1924, by his vigorous cam- paign, made himself known personally to a great number of his fellow citizens. That was an asset worth something, but it is probably offset by the fact that many who rallied to hear his speeches, but who were in the back rows, could not hear his voice. Everybody who tunes in can hear everything that the radio spellbinder has to say. Moreover, as every radio fan knows, when he hears a speech over the radio he is impressed by a certain intimacy, a sense of contact with the speaker. Especially is this true when listening in by headphones, when it seems to the auditor almost as if the orator were addressing his words to him alone. “Let me talk to a man face to face and I will convince him!” public speakers have been declaring for years. And now radio gives them at last an opportunity to make good their boast. Another thought is that those who turned out to Democratic rallies in the 1920 campaign were Democrats. They would have voted for Cox whether they nad heard him or not, for the most part. The candidate who campaigns by radio reaches a mixed audience of Republicans, Democrats, and _ inde- pendents. It is the latter who turn the tide of a political bat- tle. Regulars vote straight. It doesn’t take so terribly many independents to give one candidate or the other a victory. In 1916 it took but 591,- 385 of them to keep Mr. Hughes out of the White House and to keep Mr. Wilson in. Some of the thoughts in the minds of na- tional political leaders Herbert Hoover, about this new radio puzzle are these: Radio is a campaign bet that cannot be overlooked. It is not a substitute for political rallies, for newspaper publicity, booklets, and other tried methods of campaigning. It alone will not beat a political organization. But it is some- thing new in campaigning, something that may prove sufficiently influential to turn the tide of public sentiment. It may materially increase the number of voters. Ordinarily, 18,000,000 votes in a presi- dential election is a fine record, though in 1920, due to the heat of the campaign, almost 25,000,000 votes were cast. Take either number and 10,000,000 radio fans are a powerful element. eaten presents not a few practical problems to the political managers of the Republican and Democratic par- ties, both of which plan to use radio broadcasting during the campaign. As this was written, the most that either party had done was to arrange for the broadeasting of the speeches, the noise and the other audible features of the conventions, from Cleveland and from New York. The biggest question, cost, did not come up for solution, because the radio companies were eager to broad- cast the convention proceedings as fine programs for their audiences. This means that, whereas the national conventions of 1920 were limited to the lucky 30,000 who were able to get tickets in Chicago and San Francisco, the 1924 conventions were open to all who had the necessary receiving set. Secretary Commerce, not only is radio dic- tator of the United States, but is an ardent radio fan as well. cited by Mr. Lowry as one of the men who, while not considered good public speakers, have found themselves in demand as radio speakers because of their clearness This convention broadcasting set-up gives a fairly good idea of the oppor- tunity open to the presidential spell- binder, if he desires to talk to the whole country at once. The undertaking is an expensive one. It involves tying up im- portant trunk lines of the American Telephone and Telegraph Company from the city in which the candidate speaks for at least three hours. While the tele- phone company regarded this as a public service to its radio audience in the case of the conventions, it took a different attitude regarding messages of individual campaigners to potential voters. In national broadcasting, not only are wires tied up, but an extensive staff of en- gineers must be on the job, all over the of He is country, to see that amplifiers and trunk lines are working right. This service is expensive to the telephone company and the user alike. [™ IS true that the broadcasting com- panies who work entireiy by radio are perfecting a system of re-broadcasting, without the use of the land wires. How- ever, at the present time but one large re- broadcasting station of this sort is in operation, and it appears unlikely that this method will be sufficiently developed to cover the country in the 1924 cam- paign. An idea of the arrangements necessary for nation-wide broadcasting may be gleaned from the way the President’s recent speech before the Associated Press editors in New York was handled. . The President spoke at a luncheon at the Waldorf Hotel. His entire message, and even the side remarks of those near him, the tinkling of ice in the glasses and the rattle of dishes, was heard by radio fans all over the country, for, besides being broadcast direct from New York, the words of the President were carried also over the telephone lines to Washington, Pittsburgh, Kansas City, and Providence to be re-broadcast. It is probable that that speech, delivered to a few score of editors in New York, was heard simul- taneously by several million people. At its present stage of development, radio broadcasting probably lends itself best as an adjunct of a regular political campaign. To use radio, the candidate making a front-porch campaign, as did Mr. would use 0 But tl Mr. ¢ each ¢ Witho carry | car, é numbe addres A} spellbi privile Comm not ye few of air, cl the br: of tru Many succes: not a directl bring | throug entert: formin who ¢ sort m Tadio f B00d gg Prograr Station This Spellbin tore off @ wind) hot be

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[-up por- pell- hole S an im- ican rom eaks tele- iblic case rent dual In vires en- the trunk ice is y and com- io are sting, How- ge Te- is in that loped cam- assary y be dent’s Press The t the Mr. Harding from Marion in 1920, would be obliged to resort to the costly use of extensive land wire hook-ups. But the candidate making a tour, as did Mr. Cox, could have his speeches from each city broadcast by the local stations. Without a very great cost, he also could carry a broadcasting outfit in his special car, and thereby increase greatly the number of listeners to his train platform addresses. MAJORITY of radio stations prob- ably do not know how much the spellbinder should be charged for the privilege of using their transmitters. Commercialization of broadcasting has not yet been accomplished generally. A few of the larger stations sell time in the air, charging about $10 a minute when the broadcasting does not involve the use of trunk lines from one city to another. Many advertisers have found this a successful avenue of publicity. They do not attempt to advertise their wares directly over the radio, but endeavor to bring their names before the radio public through musicians, singers and other entertainers who are announced as per- forming “‘by courtesy of’’ the advertisers who employ them. Programs of this sort must be just as entertaining as other POPULAR SCIENCE MONTHLY audience. Acrobatics are lost to the microphone. The radio spellbinder needs a clear, concise message. He need not be an orator. In fact, many men who are not good public speakers have found themselves in demand as radio speakers. Secretary of Commerce Herbert Hoover is an example. His carefully prepared addresses, read to an audi- ence of banqueters, often is lost. Over the radio it is clear and logical. Secretary Hughes is another good radio speaker, though he is also considerable Postmaster- of an orator in public. Radio on the stump— one of the motorized loudspeaker ‘“plat- forms” that will help carry the voices of the presidential campaign to a radio audienc: that is estimated ac 10,000,000 Americans ” owe CHE PE General New and Secretary of Agriculture Wallace, both of whom have had considerable experience in broadcasting, find it a boon as a means of reaching people. HE President, who finds it difficult to speak in pub- lic, has encountered some in- teresting experiences when speaking over the radio. He is the first President whose mes- sage to Congress was broad- cast. On this occasion, the telephone company broadcast the address not only in Wash- ington, but in Providence, Dallas, Kansas City, and New York. >, and r him, 1d the o fans being cs, the d also ngton, idence e that Tadio features, for the radio fan with a On several occasions recently the speeches of President Coolidge have been heard over the radio by unseen millions, notably his address at the Lincoln’s Birthday dinner of the National Republican Club and his more Tecent speech before the Associated Press editors in New York City. In the latter case his entire message, and even the side remarks of those near him, the tinklling of ice in the glasses and the rattle of dishes, were heard by radio fans in every part of the United States While the President was speaking, the telephone com- pany engineers received a tele- graphic query from a fan in St. Louis, listening in on the Kansas City broadcast. He wanted to know what was the rustling noise he heard along with the President’s speech. ore of simul- e. yment, - itself litical didate as did good set can tune out an uninteresting Program, and tune in a more distant Station whose offering meets his fancy. his raises another question for the ‘pellbinder. The oldtime orator who tore off his coat and collar and who made 4 windmill of his body as he spoke, will hot be the speaker who holds a radio The engineers traced the rustle to its lair. It was the President fingering the pages of his message, as he read it from the rostrum of the House of Representatives. It takes a new technique in spell- binding to hold the radio audience. The person who is seated in a crowded hall at a political rally has no choice but to hear the speaker through, whether he likes it tans or not. The radio listener-in, if he wearies of the speaker, can tune him out and tune in a jazz band from another station. It takes more than cold polities to hold him. The speaker with a good string of funny stories has the advantage over the man with heavy logic. The man with a brief message, full of interesting facts, is listened to, where the windbag with an hour of flowery oratory talks to empty space, for radio puts the acid test on policies, issues, and men. Volume of voice, graceful gestures, or the all but hypnotic effect of a powerful personality will not make up for lack of logic, co- herence, and a clean-cut, convincing message in a radio speech. ieee radio listener in the quiet of his own home has opportunity to ponder on and dissect the statements that come to him through the air. He can comment aloud if he cares to in entire security. He can silence the speaker permanently so far as he is concerned by merely turning a knob. More than ever before, public speakers must stand on their own feet, and succeed or fail by their own efforts. The applause and cheering of loyal party men, who have attended a meeting for the sole purpose of stimulating enthusiasm, will not help a speaker with his radio listeners, for demonstrations of hand- clapping and shouts become merely a confused rumble in a head set that the radio enthusiast finds distinctly annoying. - Former Senator Albert J. Beveridge, (Continued on page 112)

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24 How I David Belasco, dean of American theatrical producers, with his staff of electricians, studying lighting effects on a model stage POPULAR SCIENCE MONTHLY ake Stage Sunlight By David Belasco subject. light. rapidly, and it all will look white. EN who make a study of light say that what we call light really is vibrations in the ether hitting our eyes. Certain it is that the future holds much promise for the scientific researcher in the Sunlight, Mr. Belasco’s aim, is called white But it is a combination of red, orange, yellow, green, blue, indigo, and violet. Paint these seven colors on a circular bit of cardboard, spin it In the accompanying article the famous theatri- cal producer tells of his lifelong efforts to create a true semblance of sunshine for the stage. NINCE my ceallboy days at the S Baldwin Theatre in San Francisco I have been interested in lighting. The conviction that light is the greatest external influence upon mankind always has been in me. Since the stage mirrors life, it seemed to me that light was a great force in producing stage effects. While I believe ‘“‘the play’s the thing,”’ light is an aid. It aids and abets the producer’s best efforts. I have done all in my power to forward the evolution of light as an aid to the theater. In my boyish days of barn- storming through California, I played by the light of smoking kerosene-fed lamps. This form of lighting still persists in some communities. Not so many years ago, David Warfield played ‘‘The Music Master” with kerosene lamps in a play- house in Oil City. In my eagerness to improve conditions, I once secured a dark lantern of the kind used by the gentleman burglar and his lowlier fellows. I manipulated it for concentration upon one spot in the scene that I desired to emphasize. I used light not merely to light the stage but to stress a scene. Years afterward, I employed engine - headlights, those great single eyes that pierce the night and warn us of the loco- motive’s imminence. This furnished the strong light I de- sired on some scenes. But it, too, was un- satisfactory, because it was far removed from my model— sunlight. ‘Nearer sunlight nearer perfection in stage lighting.”’ That is the ideal toward which I have been striving all my life. It was in the production of “‘Mary, Mary, Quite Contrary,’ with Mrs. Fiske, that I attained it. Through 40 years of experiment I had received much praise for my imitation of nature’s lighting, but it was only after the opening of that play that I heard the coveted words, “It is like a day out of doors!’’ The reason why lighting on many stages gives distorted pictures of life is that the light is not balanced. The average manager who wants to light his stage well turns on all the lights available. He does not realize that mere profusion of light fails to give the impression of sunlight. It gives only the impression of a vast waste of artificial light. colors, Mrs. Fiske in ‘‘Mary, Mary, Quite Contrary,’”’ the play in which Belasco finally achieved a true semblance of sunshine. the soft white light, produced by diffusion of the fundamental is reflected upon the figure of the famous From that flood of light his actors suffer. Strong light from above—em. phasizing every slightest shadow—carveg lines in their faces. It cuts gashes jp skin that is satin smooth. It makes the actor look 20 years older. It is cruel, It is inartistic. It is unnatural. Strong lights from below have a different but equally appalling effect. They distort the features. Delicate, pale faces they convert into blur. It was when I produced “Du Barry” that I first used the now well known Du Barry pink. For the scene in Dy Barry’s bedchamber I wanted a soft light that would beautify the room and its occupant. Mrs. Leslie Carter had Note how actress beautiful red hair. I wanted a light that would emphasize and yet soften its & beauty. Bright pink lights would not accomplish that purpose. I tried tint after tint of pink. At last I found one that produced a mellow, genial light. That was the origin of “Du Barry pink. My next important experiment was I” modifying the useful but inartistic ar & light. Circles of mica were placed about ‘ the lens, narrowing by degrees the field of light and enabling me to focus up0o! an object without an all-revealing glare. The circle that permitted the light from the mica-surrounded lens to pas through often was not more than an inch in diameter. This was used with gratr fying effect in ‘“The Rose of the Rancho. As the curtain rose upon that play 0 Spanish life in America an old priest was TPE BRIS cys lig] lar Su: gal din to sec pre gay W: do] Ste Tac did in dis pla the

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tors rves ich ow tal ess at that en its | ld not od tint nd one light. pink.” was in tic are 1 about he field is upon g glare. p light to pass an inch h grati- ancho." play of jest was discovered asleep in an arbor. The narrow rav of light from this contrived circle was directed upon two grape leaves in the arbor. The light was reflected upon the face of the sleeping monk. At the gate of the monastery the light was directed in the same manner upon two leaves. The light from the leaves was reflected upon the grass. T IS for such touches that applause is heard in my theater when the curtain POPULAR SCIENCE MONTHLY ditorium. They were arranged in groups with amber shades in the ceiling. Along the floor the amber lights were repeated. The lights arranged along the wall had white silk shades. The side lights were brighter and harder, so that audiences might find their seats. One of my most gratifying experiments was when I produced ‘“‘The Return of Peter Grimm.” It was necessary that Peter enter the room where his friends were talking about him, without their see- Machine shop in the electricians’ room of the Belasco Theatre, showing Mr. Belasco (third from the left) and his assistants at work in their experimental lighting laboratory rises upon the first scene. My gracious audience recognizes that by some novel means a natural effect has been secured and thus gladden my heart by their approval. For the production of ‘“‘The Rose of the Rancho” I had six men working at the lights. I needed all of them to give the impression of outdoors in the garden life of California. It was pleasing, and friends and critics assured me it was a triumph. But I was not satisfied. My next invention was the baby light. The are light was ponderous, overwhelm- ing. It refused to be tempered to the point of softness that I required. There- fore I worked out the plan for the baby light. It is a lens about one fourth as large as the are. It is incandescent. Suspended from the gridiron and the galleries, baby lights can be regulated by dimmers to the gentlest glow. I gave my attention for a long time to reflectors. How to arrange them to secure the right degree of glow was a problem. We worked and worked. I gave five days to a rehearsal of lights at Washington. It cost me a thousand dollars a day, but it was worth it. OKILFUL manipulation of the lights by means of reflectors was a long step. But it did not take me to my goal. had passed my brother managers in the Tace, but that had little significance. They did not care about lighting. I did. _ When I opened the Belasco Theatre In New York, something occurred that disturbed my audiences and the critics. © can’t read the programs,” they com- Plained. “We can’t see our friends in the audience.” “You will grow used to it,” I answered. There were 4000 lights in the au- ing him. It was necessary, too, to convey that he was dead. I did this by keeping the back part of the stage dim and by picking out Peter Grimm (Mr. Warfield) with a light. Every one of the players was followed about by a light. But still I was not satisfied. I wanted something better. I found it when Mrs. Fiske appeared upon my stage last season. With “Mary, Mary, Quite Contrary,’ my dream of 40 years came true. I had se- cured a true semblance of sunshine. This was done by dif- fusion of light. Upon a sheet of heavy glass, mottled paper was spread and fastened. Over this were placed sheets of silver leaf. The silver leaf was colored in the fundamental hues. The plate of glass, mottled paper and silver leaf was attached to the stand of a baby light. It threw a soit light instead of a glare. Light reflected from the invention had solved my problem. HE light diffused upon the stage created the illusion of sunshine. To actually reproduce nature on the stage would have been crude, prosaic. We had approached as near to nature as the stage allows. To come as near to it as I have with my artificial sunshine is the thing. I have heard it is the 25 last word in stage lighting. Perhaps. Light must come from the right lamp to produce the right illusion. I have lamps from every part of the world— 2000 of them. Some of them are in my shop in the basement of my theater. But they have overrun the shop. Many of them have had to be sent to the store- house. I have need of all of them. One day last week I found in an auction sale a beautiful old Italian lamp. I may pro- duce an Italian play some day and that lamp will be an asset. WOULD not finish this contribution without a word to the home makers. Light is as great an aid in the home as in the theater. Issuing through colored shades it leads an army of beneficent sentiments. Many a girl has brought the bashful suitor to a proposal with the help of a delicately tinted pink lampshade. Whereas darkness breeds villainies. You may cry “extravagance,” but no worthy ideal is extravagant. Let us have plenty of light—the right light—in our homes. We can adapt an idea according to our purses. The most used room in a house should have three kinds of lights. There should be lights from a chandelier—be sure to make pink shades for it—for general use. There should be a reading lamp to throw the glow upon the page instead of the eyes. Eyes should not have to do battle with a strong light. They focus upon but one The lamp room in the basement of the theater. Here Mr. Belasco has collected 2000 unusual lamps from all parts of the world. He says he has need of every one of them—for atmosphere or light third of the page, the black print. There should be a lamp that will diffuse the light through the room. There are lamps that cast the light upon the ceiling, which light is reflected upon the floor. That is the light in which to live, the best light for art and for service. An unusually practical article in next month’s issue will describe in detail how to wire your home for radio.

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POPULAR SCIENCE MONTHLY Desert Cliffs Yield Ancient Secrets F AMERICA’S little-explored nat- ural wonders that are being opened to tourists by the comple- tion of new automobile highways, few are more interesting from a scientific stand- point than the majestic cliffs that mark the site of ancient lakes in the now waterless wastes of the Mojave Desert in southern California. Here from the depths of deep defiles rise great buttressed walls fashioned through the ages by nature’s architecture. These strange formations in the heart of desert lands hold for the scientific explorer a fascinating story of the ages, giving up new secrets of evolution on the American continent. Millions of years ago, geologists tell us, the present waterless country of the Mojave Desert was dotted with lakes and rivers. Into the lake waters year after year spring freshets and floods washed sand and clay, laying down layer after layer of mud in the lake bottoms. Now, by some unrecorded convulsion of the earth, these lake bottoms have been lifted up, and the rains of the cen- turies gradually have cut through them, creating the buttress-like formations. The projecting, shelflike layers in this picture mark the harder strata, where the ma- terial deposited in the ancient lake bottom happened to be sandier and solider than usual. These harder strata have resisted the rains more than the rest. In the softer clay between the harder layers, modern geologists have found th bones of animals long extinct—animals that reveal important stages in evoluticn as it was enacted on the North America continent. The clay layers have yieldec, for example, the bones of a remote ances- tor of our modern horse. CIENTIFIC interest in these dis- coveries has been increased by the re- cent finding of five prehistoric human skeletons, standing upright in undisturbed strata at Los Angeles, only a comparative- ly few miles to the west. Scientists be- lieve the skeletons date to the last Ice Age, 125,000 or more years ago. Further excavations will be undertaken in the hope of revealing relics of glacial days.

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the mals ticn ican dec, 1ces- e re~ man rbed tive- be- Ice ther the POPULAR SCIENCE MONTHLY * Courtesy Mount Wilson Observatory One of the unfathomed mysteries of the heavens is the great dark nebula in the constellation of Orion—a black ‘‘hole in the sky”’ seen near the center of this magnificent photograph made with a powerful 100-inch reflector. It is called ‘‘the Horse’s Head.”” Astronomers be- lieve it actually is a colossal mass of non-luminous matter that blots out the light of bright stars beyond it—possibly a strangely shaped “dead universe,’’ a heavenly derelict floating through space at dis- tances so vast that our minds cannot begin to comprehend them The World’s Greatest Spectacle By Raymond J. Brown O DOUBT you have read about the work of uncovering the tomb of Tutankhamen. Probably you have been greatly impressed, for there is drama and thrill in the thought of men cutting their way into a place that had been seen by no eye and touched by no hand in more than 30 centuries. Suppose, though, that some one were to when you saw them you actually would be carried back at least 10,000 years. For those cloudy patches are star clusters, con- taining tens of thousands of stars, some undoubtedly larger and brighter than our sun, but so far away from the earth that their light, traveling 186,000 miles a second, requires 10,000 years to reach us! Which means that when you see that light, you actually see something that left dawn of the oldest civilization that ex- isted on earth! A perfect link between the present and the past! Moreover, though some of these far- distant star clusters cannot be seen with- out the aid of powerful glasses, they are so large that it would take a heam of light 500 years at least to cross one. And only from those relatively close does the light reach us in so short a time as 10,000 years. stop you today and offer to take you back 70 or 80 centuries be- fore the time of Tutankhamen; to let you see with your own eyes certain events of 10,000 or 11,000 years ago—not reproductions of those events, nor relics of them, but the actual events them- selves? What do you think you would say? You probably would think the Suggestion absurd, and yet if the man who made it happened to be an astronomer with a telescope, he could fulfil every one of his promises. For if you care to see certain events that antedate the beginning of the Christian era by at least 8000 years, it is neces- sary for you merely to go out of doors any one of these clear sum- mer nights and look at the sky through a telescope. Here and there in the heavens the telescope would disclose Cloudy patches of light, and those stars thousands of years before the The Tremendous Mystery Story of the Sky R. BROWN'S story of the wonders of the heavens and their immensities gives us a new sense of the mystery and adventure of life. He tells us, for example, of the recent discovery of a faint luminous haze—another distinct universe of suns and planets like our own universe of the Milky Way, yet so far distant that to reach us its light, speeding 186,000 miles a second, must travel for a million years! A universe five times as distant as the farthest star in the Milky Way, too far away for our eyes to see it or for our minds to comprehend it; too far away for our most powerful telescopes to catch more than its hazy, cloudlike luster! Such figures make us wonder if, after all, there is a limit to bigness and to smallness. And yet by correct observations of these tremen- dous heavenly bodies your daily life is regulated. Your watch, your clock, the vessels on the seas, and the trains on the land—all depend on the astrono- mer’s telescope.—THE EpirTor. Astronomers estimate that the light from many of them does not reach us in less than 200,000 years, while only a few months ago there was discovered in the constellation Sagittarius a faint haze whose light is estimated to take 1,000,000 years in its jour- ney to the earth! This is by far the most distant object ever viewed by man, and yet astron- omers do not say that it marks the limits of the universe. They have formed an opinion regard- ing the extent of space, but that opinion is not based on actual measurements, for even the mar- velous instruments of modern astronomy are incapable of measuring the distance from us of masses, which, while probably made up of as many as 100,000 suns, still cannot be seen except with the help of a powerful tele- scope! To speak of the components of those distant patches in the skies

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28 as “‘suns” is quite correct. All stars are suns, and the sun isastar. Also, our sun, which seems to us the undoubted ruler of the heavens, is only an average star. In an area of the Milky Way only as large as the full moon, telescopic photographs have shown 80,000 stars, as many of which are Jarger than the sun as are POPULAR SCIENCE MONTHLY tance from us is 1200 million billion miles? To give an intelligible idea of distances like this, astronomers have selected the light-year as their unit of stellar measure- ment. This is the distance that light will travel in a year—approximately six trillion (6,000,000,000,000) miles. In the Write that number down—a “‘1”’ and 15 ciphers—then try to compute how long it would take the Shenandoah, with her cruising speed increased to 100 miles an hour, to fly there from the earth! Then remember that these stars are our next- door neighbors, and that only a few of them are so near us. In fact, smaller. N ANY of the tiniest specks of light you see in the sky on a clear moon- less night are stars that are immensely greater than the sun. In fact, if you pick out any faintly luminous star at random, the chances are that it is just as bright as the sun, just as large (about 855,000 miles in diameter) and of about the same mass, which is about two billion billion billion tons. If you pick out a brighter star, it is altogether likely to be a greater sun than ours. It might even be Antares, which is 400 times larger than the sun, or Betelgeuse, more than 200 times larger, or Arcturus, about 25 times larger. There ire between two billion and three billion stars from which you may _ choose, according to the estimates of astronomers, although only a few of these can be seen without a_ telescope. When you look up at the sky on a clear night, the number of stars you see may impress you as running into the millions, yet actually not more than two to three thousand are visible to the unaided eye from any one place on earth. If you could make observations from sev- eral parts of the earth you might count between six and seven thou- sand. Seventy-five per cent of these are giant stars, such as Antares, Betelgeuse and Aldebaran. OW, many of the two to three billion suns that we call stars are believed to be like our sun in at least one other im- portant respect. Around them satellites are whirling just as around our sun revolve the earth and the seven other planets. In other words, what people on the earth are accustomed to regard as the world, or the universe—the sun and its planets with its star-studded canopy of sky—actually is only an infinitesimal speck in the real uni- verse. It is only one of several thousand —possibly several hundred thousand or several million—other worlds that lie in the depths of space. To attempt to measure the size of the real universe in miles would be futile and merely confusing. To most of us distances greater than 25,000 miles, the approxim- ate circumference of our relatively tiny earth, are incomprehensible. Thus, even to speak of the sun being 93,000,000 miles away from the earth—a short dis- tance by the standards of stellar space— conveys no clear impression. What are we to say, then, of the star clusters whose dis- Courtesy Mount Wilson Observatory Trifid nebula in the constellation of Sagittarius, apparently a cloudy patch of white-hot gases almost invisible to the unaided eye case of those far-away star clusters, astronom- ers would say that they are 200,000 light-years from the earth, which means that it takes light 200,000 years to pass from them to the earth. When we re- member that light from the sun reaches us in a little more than eight minutes, we begin to perceive what stellar distances actually mean. For example, Alpha Centauri, one of the closest stars to us, is 25 trillion miles, or more than four light-years away. Sirius, one of the brightest stars that we see, is more than twice this distance from the earth. The mighty Betelgeuse, which, for all its vast size of sun, seems just a extinct. million billion miles away from us. 200 times that of the red button on the shoulder blade of Orion, is more than a only about 30 lie within 109 trillion miles, or about 17 light-years from the earth. And only a thousand or go of the remainder are at dis- tances from the earth that can be computed within hundreds of billions of miles, The rest—and remember there are between two and three billion at least—may be anywhere from 50 to a million light-years away. Science doesn’t know, nor can the most delicate in- struments and _ ingenious methods yet devised fathom, the true distances of space. ITH facts like these regarding the great known stars in mind, at- tempting to form a mental vision of the prodigious ex- tent of the universe is awe- inspiring and_ bewildering. As a single example of how utterly impossible it is for us, to whom the speed of an express train seems terrific, to picture adequately the sublime wonders of the heavens, take the great nebula in Andromeda. A nebula may be defined as a celestial cloud, a mass of light, a mist of fire, ap- parently composed of a huge expanse of white-hot rarefied gases. Some astron- omers believe that the neb- ulae are the source of stars. Courtesy Mount Wilson Observacory The star cluster of Hercules that to any but powerful telescopes appears as a hazy patch. many millions of miles apart, and so far away from us that theif light would be visible thousands of years after they had becom¢ Each pinpoint of light in the photograph is a sun. Many of them are far larger than our own, and probably, like ours, are the centers of solar systems of planets and moons. In reality it is a group of countless suns Now, the nebula in Andromeda is 100 million times as large as our sun. Its diameter is a million times greater than the distance between the sun and the a ae ts i GN Raa Per} FRAG ey Were oC en se Be eas ru [er ie tse i ade alia ; Fr ~~ 1A Dae

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nd 15 ong it 1 her es an Then next- ew of n fact, in 100 ut 17 earth. or so at dis- n that within miles, ember Oo and —may 0 toa away. W, nor ite in- ‘enious thom, space, these great id, at- mental DUS ex- is awe- dering. of how is for d of an terrific, ly the of the great L. defined a mass ire, ap- of a Lite-hot astron- he neb- { stars. ervacory sopes suns theit come sun. like oons. 2 is 100 in. Its er than ind the ii aa earth. If you could place a radio trans- mitter on one edge of it and a receiver on the other, a signal sent out by the one would not be received by the other for almost 20,000 years. And yet, were an astronomer to give you the exact location of this huge cloud of fire, you probably would strain your eyes vainly to see it unless you had a telescope. For this tre- mendous area of luminous gas is compar- able with the entire expanse of the heavens as a single drop of water is with the torrent of a Niagara. And that is not because it lies at the outer boundaries of space. On the contrary, by the reckoning of astronomers, it is only in the middle distance. HIS nebula is moving slowly toward the earth—slowly, that is, according to the speed at which celestial bodies move. It is approaching us at something around 200 miles a second—about 60 billion miles a year. Some day it may reach us, but that fact need occasion us no alarm. For the nebula is so far away that, even moving at a rate of 60 billion miles a year, it would not approach per- ceptibly closer to usin a POPULAR SCIENCE MONTHLY When you see these huge masses of rock burst into flame in the air, you say you have seen a “shooting star.”’ The little streak of fire seems to be far out in space among the stations of the heavenly bodies whose distance from us is measured in light-years. Actually, though, it is only between 20 and 80 miles away. At the greater distance the meteorite, which is traveling about 25 miles a second, begins to glow. It rapidly reaches full flame; at 20 miles it is en- 29 tails of comets without harm. Comets come and go. They pass out of our field of vision eventually only to be led back into it again by the sun’s gravity and to become visible to us once more. Just as the “‘shooting stars’? appear to be far out in space, all the heavenly bodies, with the possible exception of the moon, seem the same distance away. The sun and the moon appear to be larger than the stars, some stars appear fainter than tirely consumed. Sometimes countless millions of these meteorites make up a little army of their own and start marching through the heavens. When such a swarm travels close enough to the sun to be influ- enced by its gravitational billion years! And re- member that this fiery cloud is reasonably close to us if we com- pute its distance by the tremendous standards of the skies! Sometimes we have visitors from the heav- ens. You have seen them in museums. Pos- sibly one has reached the earth close enough to your home for you to have seen it before a museum claimed it. These visitors look like huge rocks, although they often are solid metal, and are called “meteorites.” They are bits of cosmic flot- sam, varying in weight Courtesy Mt. Wilson Observatory The spiral nebula, Canes Venatici, photographed with a 60-inch re- flector. Astronomers tell us that the galaxy of the Milky Way, of which our own little solar system is a comparatively insignificant part, may itself be a spiral nebula much like this—a whirling discus of stars, so huge that it takes from 25,000 to 50,000 years for light to travel from one side to the other! Our sun is comparable with one of the tiny specks of light on the outer edge of the circular mass others, but, unless you knew otherwise, it is scarcely likely that you would attribute these differences in size and luminos- ity to their real cause —the between an ounce and more than a ton. As- tronomers say that The Morehouse comet, as photographed at the Yerkes Observatory in 1908. from ten to a hundred million of them are furled at the earth every day. Few, though, reach the earth’s surface. The rest are burned in the heat generated by the resistance of the earth’s atmosphere to their terrific speed. Courtesy Mt. Wilson Observatory In the center of this photograph is seen the mysterious S-shaped dark nebula of Ophinchus, surrounded by countless jewel-like suns © Keystone It is made up of countless millions of meteorites whirling around the sun in a swarm, sweeping a huge “‘tail’’ of vaporous matter. The tail, many millions of miles in length, was not visible to the naked eye. Note how the far distant stars shine through the diffused cloud-like substance of the tail force, it begins to whirl around the sun—as the earth does—and becomes a comet. From the rear of this army, and in a direction away from the sun, sweeps a huge “tail”? of vaporous matter. Many times the earth has passed through the widely varying distances of the heavenly objects. This is scarcely remarkable since it is true also when you view far- distant objects on earth. Now, even to the instruments of astron- omy, the far-distant objects in the heav- éns—star clusters, for example, that may be from 50,000 to 200,000 light-years away—seem to vary in size and luminos- ity, but the fact that their distances vary widely is not readily apparent. That is why astronomers can offer only estimates of the approximate distance from us of the stellar bodies that lie close to the apparent limits of space. FTER observing thousands upon thousands of stars, however, astron- omers have learned to interpret differ- ences in luminosity in terms of differences in distance; hence, they are able to make quite accurate estimates of the distances of the most remote heavenly bodies by comparing the amount of light they give off with the amount of light that issues from stars of known distance. In other respects, too, they have as- sumed the stars about which definite information has been obtained are typical (Continued on page 113)

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30 POPULAR SCIENCE MONTHLY “Flying Autos in 20 Years” An Expert's Visionary Picture of Motor Travel in the Future \ ,' YITHIN the next two decades autos will be made with folding wings, so that when on a straight stretch of road they can be spread and the machine will take to the air. The present- day tendency to lighten the construction of automobiles through the extensive use of aluminum alloys, without sacrificing the safety factor, and the great progress made in airplane construction as the result of recent experiments with motorless gliders, as well as motor gliders, are the two factors that will make this possible. This combination automobile - airplane will have a body shaped similar to the present hydroplane hull, mak- ing it both a water and land machine. The wheels will protrude sufti- ciently to permit the machine to be driven on the highway after the wings have been col- lapsed, propeller disengaged and the automobile control mechanism applied, which in reality will give a three-in-one conveyance. MAGINE the convenience of being able to drive around in the city, as is done nowadays, and then when you start for some other town and get on a straight of way or enter a near-by pasture, to unfold the wings on the ma- chine and take to the air! It will mean quicker transporta- tion for the suburbanite, for people living at a distance from a large city, and for the traveling salesman who now uses the motor car and highways to cover his ter- ritory. Recent glider trials held throughout Europe have shown ways of increasing the lifting power, while reducing the spread of airplane wings. Further, it has been demonstrated that with properly con- structed wings and properly designed motors it is possible to fly almost any type of fuselage. The development of automatic safety devices to control flight will decrease the liability of accident. Today, flying is no more dangerous than motoring on the ~~ ~ How the fiying roadster may appear if Captain Rickenbacker’s predic- tions are fulfilled a model built by Allen H. Russell of Nutley, N. J. By E. V. Rickenbacker Ace of Aces in the World War streets and highways—sometimes I think not as dangerous. However, people have a fear of flying that will have to be over- come just as they had to overcome their fear of traveling 20 miles an hour in the horseless carriage of 20 years ago. Save in time of war, there is no need for Our artist’s conception of the automobile- hydroplane of the future as predicted by Capt. E. V. Rickenbacker. The machine would be equipped with folding wings for flight and with pontoons for water travel stunt flying, and that is the only really dangerous part in flying. It is a good bit like driving through heavy traffic at 60 miles an hour—every one doesn’t have the skill to do it. Rigid rules will be laid down for flying, much the same as there are rules for vehicular traffic today. In the combined automobile-airplane I see a machine that is not greatly dif- ferent from the present-day motor car, except in its decreased size. The body will be nar- rower and shorter, to reduce weight, and will be of a modified stream- line design. The engine will be made lighter and smaller, but with about the same horsepower as is used today through the use of a supercharger. The wings will fold back against the sides of the car when driving along the street and will have sufficient span to lift the car off the ground at a moderate “take-off” speed. The 25-foot span that it is possible to build on the present-day motor-car—1214-foot wings on each side —will be sufficient to lift the lighter and more efficiently built machine of 1940. ONSIDER what such a machine will mean to the man who works in the city. He could live several miles farther away from the heart cf the city and spend less time getting to and from work. By flying, more speed could be made with a greater degree of safety than now is pos- sible on the streets and highways. It would not take a great stretch of im- agination to foresee municipalities regu- lating the height of buildings to uniform- ity, the streets to be bridged, in order to form one vast landing-field in the center of each city for flying machines. The land- ing-field or tops of the buildings could be connected with the street level by elevators so that a machine alighting could descend to the street and _ be driven about as an automobile. At the end of the business day it would be driven Rickenbacker as an automobile speed king back to the elevator and lifted to the roof to take off for the homeward flight. Such a forecast is more than pure fancy. It is founded on present progress in automobile and airplane design. EXT month: A dramatic story of a young immigrant who, by his own mechanical efforts, found a way (to travel on land faster than any other human being. His life story is a thrill- ing romance of mechanics. You cant afford to miss this unusual personal story of the swift progress of applied science. _—" ———”_ ae oS a, wl of the gin Oc dy: eve bla by qui the ant lar, Mc val an the par Va All inf. tur Ne shu cur ling pou foo har bit qui Ho we loa ine

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he he ift ite fat ay de nd vill 1er nd By 1a OS- ing roof pure Zress of a own y to ther yrill- ant onal clied = anene tone Above: Preparing to blast away a 90-ton reinforced-concrete founda- tion at the Lehigh Valley Light: and Power Company, Allentown, Pa. Dynamite charges placed in holes drilled in the face of the pier cut it neatly into blocks without disturbing near-by machinery. At the right: Dynamiting a concrete pit at the Philadelphia Dupont Paint Works—a view after the first shot. Not a window-pane in the building at the left was broken By H. E. Davis OVING mountains, turning rivers M from their courses, or leveling + huge barriers of rock by the use of dynamite are tremendous feats, yet they are performed so frequently in en- gineering projects that they no longer occasion surprise. Recently, however, dynamite has been put to a variety of new uses, which, though less spectacular, are even more remarkable than the giant blasting operations usually accomplished by means of this powerful explosive. Dynamite now is being used in small quantities as a substitute for the pickax, the sledge, the crowbar, or the cold chisel and hammer in such unusual places as large factories, or even the holds of ships. Moreover, it is being fired in the midst of valuable machinery, electric switchboards, and similar equipment without stopping the machinery or even breaking a window- pane! Recently, for example, the Lehigh Valley Light and Power Company of Allentown, Pa., wished to remove the re- inforced-concrete foundations of three turbine generators. Each foundation was 12 feet square and weighed 90 tons. Near by was machinery that could not be shut down without cutting off the electric current from several towns and trolley lines. A 22-inch steam pipe carrying 250 Pounds pressure to the inch ran within a foot of the foundations. Drilling holes with jumpers and sledge ammers and breaking the concrete off bit by bit with wedges would have re- quired 10 weeks. The company decided to try dynamite. Holes four feet deep and 15 inches apart Were drilled in the face of the pier and loaded. Each charge consisted of a three- inch section of a one inch by eight inch POPULAR SCIENCE MONTHLY Dynamite, Industry’s dynamite cartridge primed with an elec- tric blasting cap. On top of the charge tissue paper was tamped in lightly to afford a two-inch air space, and then wet clay was tamped tightly to the mouth of the hole. A blast- ing mat was placed over the foundation, and when the shot was fired, it simply eracked the concrete without throwing any fragments. By successive shots the pier was cut into blocks as neatly as if with a chisel. The operation of the plant was not inter- rupted, nor was any damage done. VEN a more remarkable instance of the new use of dynamite took place in an electric-lighting plant in Denver, Colo., where gelatin dynamite was em- ployed to remove a solid cast-iron pulley wheel weighing more than a ton from a shaft to which it was rusted fast. Charges of the explosive, skilfully fired in holes drilled in various parts of the wheel, shot away the spokes, split the rim, and finally cracked the hub into two pieces that dropped to the floor, leaving the shaft entirely unharmed. The total amount of explosives used in breaking up the wheel was 30 sticks of New Pick and Sledge dynamite, 50 caps, and 40 feet of fuse, making the whole cost of materials less than four dollars. T SPOKANE, Wash., a steel reinforced-concrete smokestack, 10 feet in diam- eter at the base and 210 feet high, located on a deserted crematory site, caused the city engineers much anxiety until they decided to bring it down with explosives. Sixty- five holes were drilled around two-thirds of the circumfer- ence, in a belt about four feet wide and a few holes in the remaining third, leaving about four feet intact. The 65 holes were loaded and fired in groups to blast out the concrete. The steel reinforcing bars then were cut with an acetylene torch. A cable attached to the stack 100 feet above ground was tightened after each shot and after cutting the steel, caus- ing the stack to be pulled about 214 feet out of line. The holes in the remaining circumference then were loaded and fired, and the stack, breaking the reinforcing rods, fell in the desired place. PRUAStING in the hold of a ship may sound like a rash proceeding, but the Charleston Shipping Company of Charles- ton, S. C., will testify that dynamite re- cently saved them three days’ time and 50 per cent of labor in unloading a cargo of potash that had become caked in the hold so hard that breaking it up with picks was extremely slow work. Thus, in our ports in the midst of ship- ping, in busy city streets, and in indus- trial plants running at full speed, small charges of high explosive can be directed with the greatest nicety. How a 210-foot rein- forced-concrete smoke- stack at Spokane, Wash., was felled by dynamite. Above: Cutting the steel rein- forcing bars after the concrete base had been blasted. At the left: The fallen smokestack

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30 POPULAR SCIENCE MONTHLY “Flying Autos in 20 Years” An Expert's Visionary Picture of Motor Travel in the Future X YITHIN the next two decades autos will be made with folding wings, so that when on a straight stretch of road they can be spread and the machine will take to the air. The present- day tendency to lighten the construction of automobiles through the extensive use of aluminum alloys, without sacrificing the safety factor, and the great progress made in airplane construction as the result of recent experiments with motorless gliders, as well as motor gliders, are the two factors that will make this possible. This combination automobile - airplane will have a body shaped similar to the present hydroplane hull, mak- ing it both a water and land machine. The wheels will protrude sufti- ciently to permit the machine to be driven on the highway after the wings have been col- lapsed, propeller disengaged and the automobile control mechanism applied, which in reality will give a three-in-one conveyance.

<s Sage ' MAGINE the convenience of being able to drive around in the city, as is done nowadays, and then when you start for some other town and get on a straight of way or enter a near-by pasture, to unfold the wings on the ma- chine and take to the air! It will mean quicker transporta- tion for the suburbanite, for people living at a distance from a large city, and for the traveling salesman who now uses the motor car and highways to cover his ter- ritory. Recent glider trials held throughout Europe have shown ways of increasing the lifting power, while reducing the spread of airplane wings. Further, it has been demonstrated that with properly con- structed wings and properly designed motors it is possible to fly almost any type of fuselage. The development of automatic safety devices to control flight will decrease the liability of accident. Today, flying is no more dangerous than motoring on the ost —

How the flying roadster may appear if Captain Rickenbacker’s predic- tions are fulfilled

—a model built by Allen H. Russell of Nutley, N. J. By E. V. Rickenbacker Ace of Aces in the World War streets and highways—sometimes I think not as dangerous. However, people have a fear of flying that will have to be over- come just as they had to overcome their fear of traveling 20 miles an hour in the horseless carriage of 20 years ago. Save in time of war, there is no need for Our artist’s conception of the automobile- hydroplane of the future as predicted by Capt. E. V. Rickenbacker. The machine would be equipped with folding wings for flight and with pontoons for water travel stunt flying, and that is the only really dangerous part in flying. It is a good bit like driving through heavy traffic at 60 miles an hour—every one doesn’t have the skill to do it. Rigid rules will be laid down for flying, much the same as there are rules for vehicular traffic today. In the combined automobile-airplane I see a machine that is not greatly dif- ferent from the present-day motor car, except in its decreased size. The body will be nar- rower and shorter, to reduce weight, and will be of a modified stream- line design. The engine will be made lighter and smaller, but with about the same horsepower as is used today through the use of a supercharger. The wings will fold back against the sides of the car when driving along the street and will have sufficient span to lift the car off the ground at a moderate “take-off” speed. The 25-foot span that it is possible to build on the present-day motor-car—1214-foot wings on each side —will be sufficient to lift the lighter and more efficiently built machine of 1940. ONSIDER what such a machine will mean to the man who works in the city. He could live several miles farther away from the heart cf the city and spend less time getting to and from work. By flying, more speed could be made with a greater degree of safety than now is pos- sible on the streets and highways. It would not take a great stretch of im- agination to foresee municipalities regu- lating the height of buildings to uniform- ity, the streets to be bridged, in order to form one vast landing-field in the center of each city for flying machines. The land- ing-field or tops of the buildings could be connected with the street level by elevators so that a machine alighting could descend to the street and be driven about as an automobile. At the end of the business day it would be driven Rickenbacker as an automobile speed king back to the elevator and lifted to the roof to take off for the homeward flight. Such a forecast is more than pure fancy. It is founded on present progress in automobile and airplane design.

pow month: A dramatic story of a young immigrant who, by his own mechanical efforts, found a way to travel on land faster than any other human being. His life story is 2 thrill- ing romance of mechanics. You cant afford to miss this unusual personal story of the swift progress of applied science.

“nt

| ween.

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9 the the POPULAR SCIENCE MONTHLY Dynamite, Industry’s New Pick and Sledge dynamite, 50 caps, and 40 feet of fuse, making the whole cost of materials less than the » lift rate that -day side and D. will | the ‘ther pend By ith a pos- f im- regu- ‘orm- er to ter of land- ld be with level rs so chine could » the 1 be ut as obile. of the ay it lriven i king he roof n pure rogress ry of a vis own way to y other » thrill- u can’t ersonal applied Above: Preparing to blast away a 90-ton reinforced-concrete founda- tion at the Lehigh Valley Light: and Power Company, Allentown, Pa. Dynamite charges placed in holes drilled in the face of the pier cut it neatly into blocks without disturbing near-by machinery. At the right: Dynamiting a concrete pit at the Philadelphia Dupont Paint Works—a view after the first shot. Not a window-pane in the building at the left was broken By H. E. Davis OVING mountains, turning rivers M from their courses, or leveling + huge barriers of rock by the use of dynamite are tremendous feats, yet they are performed so frequently in en- gineering projects that they no longer occasion surprise. Recently, however, dynamite has been put to a variety of new uses, which, though less spectacular, are even more remarkable than the giant blasting operations usually accomplished by means of this powerful explosive. Dynamite now is being used in small quantities as a substitute for the pickax, the sledge, the crowbar, or the cold chisel and hammer in such unusual places as large factories, or even the holds of ships. Moreover, it is being fired in the midst of valuable machinery, electric switchboards, and similar equipment without stopping the machinery or even breaking a window- pane! Recently, for example, the Lehigh Valley Light and Power Company of Allentown, Pa., wished to remove the re- intorced-concrete foundations of three turbine generators. Each foundation was 12 feet square and weighed 90 tons. Near by was machinery that could not be shut down without cutting off the electric current from several towns and trolley lines. A 22-inch steam pipe carrying 250 pounds pressure to the inch ran within a foot of the foundations. Drilling holes with jumpers and sledge hammers and breaking the concrete off bit by bit with wedges would have re- quired 10 weeks. The company decided to try dynamite. Holes four feet deep and 15 inches apart Were drilled in the face of the pier and loaded. Each charge consisted of a three- Inch section of a one inch by eight inch dynamite cartridge primed with an elec- tric blasting cap. On top of the charge tissue paper was tamped in lightly to afford a two-inch air space, and then wet clay was tamped tightly to the mouth of the hole. A blast- ing mat was placed over the foundation, and when the shot was fired, it simply cracked the concrete without throwing any fragments. By successive shots the pier was cut into blocks as neatly as if with a chisel. The operation of the plant was not inter- rupted, nor was any damage done. VEN a more remarkable instance of the new use of dynamite took place in an electric-lighting plant in Denver, Colo., where gelatin dynamite was em- ployed to remove a solid cast-iron pulley wheel weighing more than a ton from a shaft to which it was rusted fast. Charges of the explosive, skilfully fired in holes drilled in various parts of the wheel, shot away the spokes, split the rim, and finally cracked the hub into two pieces that dropped to the floor, leaving the shaft entirely unharmed. The total amount of explosives used in breaking up the wheel was 30 sticks of four dollars. T SPOKANE, Wash., a steel reinforced-concrete smokestack, 10 feet in diam- eter at the base and 210 feet high, located on a deserted crematory site, caused the city engineers much anxiety until they decided to bring it down with explosives. Sixty- five holes were drilled around two-thirds of the circumfer- ence, in a belt about four feet wide and a few holes in the remaining third, leaving about four feet intact. The 65 holes were loaded and fired in groups to blast out the concrete. The steel reinforcing bars then were cut with an acetylene torch. A cable attached to the stack 100 feet above ground was tightened after each shot and after cutting the steel, caus- ing the stack to be pulled about 214 feet out of line. The holes in the remaining circumference then were loaded and fired, and the stack, breaking the reinforcing rods, fell in the desired place. nee in the hold of a ship may sound like a rash proceeding, but the Charleston Shipping Company of Charles- ton, S. C., will testify that dynamite re- cently saved them three days’ time and 50 per cent of labor in unloading a cargo of potash that had become caked in the hold so hard that breaking it up with picks was extremely slow work. Thus, in our vorts in the midst of ship- ping, in busy city streets, and in indus- trial plants running at full speed, small charges of high explosive can be directed with the greatest nicety. & How a 210-foot rein- met forced-concrete smoke- ieee stack at Spokane, Wash., was felled by dynamite. Above: Cutting the steel rein- forcing bars after the concrete base had been blasted. At the left: The fallen smokestack

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“One of the prime principles of suc- cessful invention is concentration,” says Frank G. Rinsche. Here the inventive chief of the Burroughs Adding Machine Company is seen studying the mechanism of a model machine that always stands before him on his office desk and that he uses in working out his new ideas HERE is something of the inven- tor in every man. You yourself probably have a good idea or two in the back of your head that you might work out some day. No doubt your ideas are excellent, but they always will re- main ideas only unless you find what to do with them to turn them into actual accomplishments. Back in the early eighties there was a man who thought the grinding task of bookkeepers, adding and_ subtracting endless columns of figures year in and year out, was a waste of effort. He thought these thousands of workers could expend their energies in a more useful direction or could do a greater amount of the same work much more accurately if they had a machine to help them. When he told others of his idea, they laughed at him. How could a brainless machine of steel do calculating like the human mind? How could steel figures be made to think? It was absurd. Nevertheless, that man, William Seward Burroughs, stuck to his conviction that such a machine could be invented. He had the purpose, the foresight, and the inventive genius to toil ceaselessly at his self-appointed task, with the result that from his idea he ultimately developed what has been one of the greatest boons to business ever evolved—the adding machine. This would still be nothing POPULAR SCIENCE MONTHLY What to Do with a Good By Frank G. Rinsche more than an inventor’s dream but for one thing: Mr. Burroughs knew what to do with his idea! Mere ideas come readily enough. They are, perhaps, the easiest thing in the world to possess. Roger Bacon con- ceived the idea of a flying machine back in the thirteenth century, but he didn’t ‘arry out his idea to completion. So he wasn’t the inventor of the flying machine. Getting ideas seems to be the easiest part of the inventor’s job. His big work is to sort out the most practical of these ideas and give them practical expression. No man has a monopoly of ideas, no matter how specialized his field may be. | bee on my desk is a copy of the Patent Office Gazette, a government publication in which are listed all the patents granted last week. According to this list the priority ot 763 inventions has been recognized officially. This is an average week’s production of the inventive mind of America. Taken in the aggregate it is the fruit of hundreds of years of mental and physical labor. Yet I believe that not more than five per cent of these 763 inventions have any commercial value. Official records probably would support this belief. These inventions represent ideas that are clever and even brilliant; mechanical and engineering talents that are priceless; yet, with lamentably few exceptions, they are not inventions that American economic life demands nor for which it will pay its richest rewards. In other words, they are not practical. N A figurative sense, the young inven- tor is too apt to search the world over for the golden opportunity actually hidden under some prosaic mask at his own doorstep. Some of the world’s most useful inventions have been the result of overwhelming economic demands. Such an invention need not be an adding machine, a typewriter, a telephone, or other complicated apparatus. The fountain pen, rubber-tipped pen- cil, alarm clock, and safety razor are but a few items of a list that the reader can select at random that met great popular response and made fortunes for thelr inventors. Behind each one there was an industrial, commercial, or social want that had to be satisfied. However, the mere finding of a need for an invention is not enough to assure success and wealth. Others may have had the idea before. It is folly for an inventor to undertake a definite work until he has first ascertained from proper authority—the government Patent Office —what patents have been issued in his line. He can get this information at nominal expense and save perhaps years of useless toil. ; One of the prime principles of invention B 4 eel eee oO 3 —_ nn — —“~ 85 >, ame one ek af af oO 2 bie re a a a ee eee

Page 35

va ns that nor for rds. In 1. r inven- rld over actually ask at world’s en the »mands. adding one, or ed pen- are but der can popular yr their was an 1 want a need ) assure Ly have for an e work 1 proper 't Office 1 in his tion at Ss years vention is concentration. The successful Ameri- can inventor must be its faithful disciple. Through him the necessity of improving methods of handling office and shop operations will be satisfied in order to keep step with the growth of business. Manu- facturer, business man, and banker are always on the lookout for any method or machine that will decrease overhead and production costs in office and factory. N AMERICA we distribute rewards on pear alone, whether an invention was developed in a month, or a week or several years. Mr. Burroughs spent the best part of his life gaining the rewards that were ultimately his and that will come to every man who will have the perseverance to stay with a conviction that is prac- tical until he sees its fulfilment. Inventions are not accidents, nor are ideas inventions. Many practical men have ideas, but if these ideas cannot be evolved into serviceable inventions, they might as well be left un- born. The inventor of today must have a thorough training and practical experience to make a success of his calling. In our case many good sug- gestions come from the users of our machines, but the good suggestions are greatly out- numbered by the impractical ones. For instance, one of the most frequent suggestions of- fered us was a pedal for re- placing the hand-operated bar. A little thought would disclose the obvious fact that the rais- ing and lowering of a pedal would be far more tiresome than the pulling of the little bar by hand. NE time a man wrote us he had an invention that would increase the output of our machine 100 per cent by placing one adding machine behind another with a single power unit operating both, so that the second machine would duplicate all computations made by the first. He never stopped to consider that the identi- cal result could be obtained much more easily merely by inserting carbon paper between two sheets of white paper on the first machine. Invention might be defined broadly as the science of satisfying human needs. Usefulness is the only reason for inven- tion and the new method must’be simpler than the old or the invention is quickly nullified. The adding machine will serve as a good example. For almost 40 years every one connected with our inventions de- partment has been concentrating on the development of new machines and fea- tures to simplify and improve old ones or to satisfy unfulfilled needs. A particular instance of simplifying Operations is found in one of the most substantial additions we have made, that of the electrie motor. By saving the time and strength that an operator must ex- pend in pulling a handle, we have in- creased his productivity greatly and have made him happier and more contented on chines, and new devices. mometer Company, POPULAR SCIENCE MONTHLY the job. The pulling ofthe handle seemed trivial enough, yet when you multiply that pull several thousand times a day, the task becomes one that would tax the strength of a professional strong man by the same principle that ‘‘constant drip- ping finally will wear away the greatest stone.” An amusing instance comes to mind in connection with this improvement. In one of our offices we had one of the first hand duplicating machines ever built. The office boy had the time of his life running it. But as soon as the novelty wore off he began to complain about the monotony of turning the handle. Finally An Inventor Who Has Put His Ideas to Work HEN Frank G. Rinsche writes in the accom- panying article that ‘‘usefulness is the only reason for invention,” he is speaking from a lifetime of practical experience in inventive work—a lifetime devoted to the perfection and improvement of ma- chines that have saved incalculable time and labor for the merchant, the manufacturer, and the office man. For 14 years Mr. Rinsche has been active in the inventions division of the Burroughs Adding Machine Company, creating different types of figuring ma- improving their usefulness by scores of He has been identified with the Bur- roughs invention almost since its inception. Born in St. Louis in 1869, Mr. Rinsche attended public and private schools, then entered the Spangle- berger School of Engineering in St. Louis. To pay his way he worked half days and three evenings a week In 1888 he went to work for Joseph Boyer, then owner of the Boyer Machine Shop. shop that William Seward Burroughs developed his first adding machine. Mr. Boyer later became presi- dent of the Burroughs Adding Machine Company. Mr. Rinsche stayed with Mr. Boyer until 1895, when he went to England for the American Arith- later the Burroughs Adding Machine Company. He has been connected with the inventions division of the company since 1910. in a machine shop. fh ccommnntitttt Gal yo i Pye a allt ti oe the lad got a brilliant idea. He came run- ning out to the shop with it. “Say, Mr. Rinsche,”’ he called, his face fairly beaming with joy, ‘‘running that machine is darned hard work. Why don’t you hook up one of those electric motors to it so that it will run easier? I’ll bet I could turn out twice as much work then.” pli ARAPHRASING the old _ familiar story, we did, it did, he did. In fact, the boy ran off four times as many letters as he formerly did and he got more fun out of his job than he would have out of a baseball game. However, there were many obstacles between the conception and completion of this idea. For example, we had to allow for the fact that few business men, bankers, or clerks who would use our machines were familiar with the operation of an electric motor. We had to make it foolproof, for human nature is fascinated by the unknown. The spark of inventive genius that is in all of us to some extent finds its greatest help last 10 years. It was in that 33 joy in exploring a piece of machinery about which it knows nothing. In addi- tion, we had to take into consideration the fact that a careless operator might forget to turn off the electric power at night. Concentration finally guided us through these and other problems with which we spent several long and hard years. Sel- dom did we spend less that from 12 to 16 hours a day on the work. When it neared completion, 24-hour days were common to all of us. But in the end we attained not only the addition of electric power, but also an ingenious automatic cutoff that took into con- sideration the careless clerk and auto- matically stopped the motor at the end of two or three minutes after the last opera- tion of the machine. HIS is an example of get- ting hold of a good idea and giving it practical ex- pression. Among a score or two of contributions that I have made personally to the improvement and refinement of the Burroughs machines, I feel that the most worth while was this application of the electric motor. Within the next 10 years I look for even greater improve- ments in the handling of office work than there has been in the Every conceiv- able operation in the handling of figure work will be done by machinery. The business man of 1934 no more will think of returning to his office or store at night to spend long hours at the figure work of the day’s business than he will think of taking his family out for a ride in a wheelbarrow. The readers of this magazine very likely will play a large part in bringing about the day when there will be no such thing as an office where mental caleu- lations of any sort are tolerated. In conclusion, and at the risk of being thought a reactionary, I want to state another cardinal principle of the science of invention, and that is fidelity to one’s purpose. I do not believe many of the younger inventors of today appreciate the vital necessity of concentrated and unremitting toil that is necessary before specific objects are gained. HE inventive road is a rocky one, but if a man like Edison, enjoying as he does the acclaim and rich rewards the world has given him for his many con- tributions to human progress and comfort, can devote from 12 to 16 hours a day to gain still greater goals, it is not too much to expect of young inventors, potential Edisons, that they forget time clocks and outside activities when a worthy inventive project is undertaken. The Goddess of Invention is a jealous one. She demands being wooed with whole-hearted and unremitting fervor, but once her favor is won, her rewards often are the greatest that man can attain. They are rewards won for knowing what to do with a good idea.

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| 34 POPULAR SCIENCE MONTHLY Oddities of Home Workmanship j) - From old parts salvaged from a junk pile, J. H. Batchelor of Savannah, Ga., built the snappy sport roadster in which he is seen driving. On his first trip with his ue. KE creation he drove from Me Fe bs Savannah to Miami, ; Fla., a distance of more than 500 miles

This odd tree dwelling : pe represents seven months’ ' _. ~e work by Amos Espy, 82- Wes yy At a cost of $75, Frank Carring- year-old Civil War veteran : r ton, aged 72, a farmer of of Westgate, Calif. It has 4 ae ee " Washta, Ia., has constructed two attractive rooms fitted c: \ his own astronomical observa- with every modern. con- 4 ; — \ a, “p tory. The revolving roof can be venience. The first floor is ' - turned in any direction desired 30 feet from the ground ; ; : i

Using only a cross- cut saw, an im- provised hacksaw, and a knife, Earle F. Olson, a young - re y pianist of Gales- \ | His — re , burg, Ill., con- : ; - | tr structed the home- a | made baby-grand AK SP) piano with which We’ j he is shown. The instrument con- tains 5500 pieces, The odd chimney-like apparatus above is a home- sc = nea Here is Harry Belock, youthful member of made instrument designed to measure the wind re- MEER. Kuiee sani, the Brooklyn, IN. -Y., Radio Club, with the —— in oa ing acar. It was designed and built ing at the task 100-watt radio transmitter he built during y Clarence S. Bruce, an employee of the Auto- his spare hours. He claims his station, des- motive Power Plant Section of the United States ignated 2 AVC, has a transmitting radius of Bureau of Standards at Washington, D. C. 2600 miles when conditions are most favorable <, mxaei, \S = i 2 Sens

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>» How I B Skating down an in- cline and “looping the gap”’ on his head is one of the spec- tacular feats accom- plished by Hilary Long with the aid of science chute and “loop the gap’’—on my head. I do it twice a day. I am not afraid, because I know I am safeguarded by unalterable principles of science that I have trained my body to obey. The greatest circus daredevils are close students of nature’s physical laws. And the most perfect, most thrilling spectacles of the sawdust ring are those in which the principles of.science have been applied most painstakingly. In fact, practically every law of physics is brought into play in the making of a great circus— the principles of gravity, equilibrium, acceleration, velocity, centrifugal force, and the rest. Likewise, practically every branch of physics has its use—the optical, with which the magicians per- form their marvels; electricity, the secret of the fire-eaters; acoustics, the aid of the eccentric musicians; mechanics, the ready tool of every trick-playing clown and the basis for the most hair-raising thrillers conceived by clever inventors. Even when I was a boy of seven, practising my first circus stunts with crude, homemade ] AM not afraid to slide down a steep POPULAR SCIENCE MONTHLY ae of any body or object, the vertical line passing from its center of gravity to the earth must pass through its resting base, or between its bases, if there are more than cne. In man, the normal resting bases are the feet, and the line of gravity passes between them. } J] OW, in order to preserve equilibrium, Nature prefers a wide resting base. The wider the better. That is why a sailor, on a rocking ship, instinctively spreads his feet far apart. But as my job is to entertain and thrill my audiences, I reverse the proceeding. Instead of mak- ing my base of support as wide as possible, as Nature prefers, I make it as small as is humanly possible. If, while I stand on my head for my spectacular upside-down slide, some one should drop a line equi- distant between my legs, the line would pass through my head and go straight to the ground in response to the pull of gravity toward the center of the earth. My center of support is not between my feet, as it is when I am standing; but it is 35 ecame a Daredevil A Circus Acrobat’s Own Story of His Partnership with Science in Making the Big. Thrills By Hilary Long Hilary Long, daredevil, of the Ringling Brothers Circus, who says his safety lies in his knowledge of the laws of physics my problem is still more complicated. The instant my body, in this upside-down position, begins to move swiftly down an inclined plane, another factor comes into play—acceleration. If I am to preserve my balance on its small support, the line through my body no longer can be straight toward the center of the earth, but must be inclined forward to a degree, depending upon the acceleration. Just how much this inclination should be, I can determine by math- ematical calculation; but I apparatus, I learned to recog- nize the unalterable laws of physics, even though I did not know their names. When my father forbade me to join the circus, I acquired my first early training by daily prac- tice in the family barn. And with practice came confi- dence—the confidence based on a growing acquaintance with scientific principles. How is it possible, you may ask, that I ean roller- skate on my head down a chute inclined at an angle of 60 degrees, jump across an can put these findings into practice only by controlling my body perfectly to obey them. Nature is a mistress who permits no trifling. I do not juggle with Nature; I simply reach an understand- ing with her. And so I get on very well with a half-inch foundation instead of the two-foot foundation of the sailor. HIS aerial feat of mine represents just one of the ways in which equilibrium is applied in producing spec- open gap and land safely on my head? It is a simple Matter of equilibrium; I have applied the laws of acceleration and gravity to my balanced, speeding body. If I should defy these laws for the fraction of a second, disaster might result. But I never defy them. Equilibrium is one of the basic prob- lems that must be solved by the circus daredevil. To preserve the equilibrium The aerial automobile race, a mechanical thriller made possible by accu- rate calculation of distances and timing. B, race down an incline and loop the gap. finishes first, as shown. a point the size of a dime at the crown of my head! My efforts, like those of other balancers and aerialists, are toward reducing my base of support to the least possible space. But in my upside-down coasting stunt Two small automobiles, A and Although A starts first, B This is because A is made to go higher at the take-off, and so must travel a longer path to the receiving platform tacular circus feats. The most elementary balancing exercise is to make movable objects remain _ stationary while limiting the support to some small part of the per- former’s body, such as the hand, chin, forehead or shoulder. You often have seen a juggling acrobat balance on his chin or nose a long pole, at the top of which may be balanced another object, or even another performer.

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36 The longer the pole is, the more amaz- ing the feat seems to be. Yet actually the reverse is true. A long pole is far easier to balance than a short one, for the reason that a slight movement of the center of gravity can be compensated for by a comparatively slight movement of the support. A{ORe difficult than balancing an ob- 1¥i ject, is the balancing of a perform- er’s body while poised on an object. If you ever have tried to ride a log floating in the water you will realize just how \ J SG, j Ira Millette, fa- mous trapeze art- 4 ist, has mastered “4 equilibrium so that ' , { he can stand on his \ head on a_ ball balanced on the bar of a high swinging trapeze difficult it is. In this field the circus equilibrist has learned to perform feats that are almost unbelievable. Ira Millette, the American aerialist who unusual feats of swaying, swinging, and twirling high above the ground on a double trapeze, is a master of balance. In one of his acts he balances himself upside down on a ball which, in turn, is balanced on the bar of a trapeze swinging high above his audience. does “SQUALLY as important as balancing for the aerialist is the exact timing of movement so that the acrobat’s flying body and the swiftly moving apparatus will come together with clocklike pre- cision. Jennie Rooney, one of the most skilful of American trapeze performers, rightly says that time, balance, and strength form the tripod that supports the successful circus daredevil. In her whirling leaps high in the air, as she flings herself from a trapeze to her partner’s outstretched hands, Miss Rooney is able to calculate her own movements and those of her partner to a split second. One miscalculation might mean a disastrous fall. Strength counts tremendously, too. Miss Rooney looks like a young girl just out of school. Yet she has the strength of two women. She proved that not long ago when she fell from a trapeze 40 feet high, caught a rope © halfway down and clung fast to it. That was one of the most remarkable feats ever performed by a woman of the circus. Another law of physics that all aerial POPULAR SCIENCE MONTHLY performers must understand is centrifu- gal force—the force that exerts itself ever away from the center. This law is employed in all the audacious circus acts grouped under the general term of “looping.” A simple example of centrifugal force can be witnessed by any one. Fill a glass with water. Whirl it rapidly in circles outward, the circles growing larger and larger. The water will remain in the glass, even when it is in an upside-down posi- tion. Centrifugal force, moving from the center outward, presses the water against the bottom of the glass. This same force makes possible the dizzy whirling and swinging trapeze per- formances such as are accomplished by Ira Millette. Its use in circus “‘looping’’ was applied for the first time 24 years ago by. an ae eo eat _ American cy- ‘ “tt list. T he same principle applies also in the “Infernal Basket or Death Trap,” which consists of a large basket, around the inner sides of which motorcyclists speed, maintaining themselves in almost horizontal positions. Of course, while we cannot go counter to the laws of nature in the circus, we often give the im- pression of doing so. A striking example of this is the apparent victory gained over a revolving disk. The rapid rotation of the disk makes it impossible for any one to remain on its surface: for centrifugal force flings outward any object placed upon it. But if a man, stepping on the whirling disk, runs in a direction opposite to that of its rotation and slightly toward the center, it will support him. This has been accomplished by several performers on roller skates. It would seem to be a defiance of the law of centrifugal force, CENTRIFUGAL FORCE while really it is a demonstration of balance. Accurate timing, so important to the aerial performer, is one of the secrets of my headlong “loop the gap’ stunt. Likewise, it is the secret of some of the most thrilling mechanical spectacles of the circus. One of these is the aerial automobile race, invented not long ago by Emile Noiset, who was one of the first to try “looping the loop.’”’ Two small automobiles dash down a steep inclined runway, leap through the air, and land on all four wheels on a receiving platform. NE car starts the mad race slightly ahead of the other; yet, strange to say, the car that starts second arrives at the finish first. How is such a paradoxi- cal result possible? The secret lies in timing. In its leap through the air, the car that starts first is made to describe a higher arc than the second car, which means, of course, that the first car must travel a longer distance —a distance great enough to make it arrive on the other side of the gap behind the second car. The circus performer knows that it is just as important to keep the appa- ratus and machinery with which he works in perfect operating order as it is for him to observe and obey the laws of physics. This applies as well to the machinery of his body. For successful achievement he must acquire and preserve perfect health and strength. He must be clear-headed always. His nerves must be steady; his supple muscles trained to obey with per- fect movement every order flashed from his brain. 1 hl once in a quarter century of ex- perience in the circus have I known the sensation of fear. Yet it is not reckless bravado that makes the circus daredevil fearless. His fearlessness is grounded in the calm confidence that comes with knowl edge of physical laws, obedience to them, and firm reliance on their steadfastness, c The thrilling motorcycle “loop the loop’’ is made possible by applying the Jaw of centrifugal force—the same force that keeps the water from spilling from a glass that is swung in a circle. LV CENTRIFUGAL Fi | FORCE PRESSES THE LIQUID, 77 AGAINST BOTTOM OF GLASS \ ‘Goes > Just as centrifugal force presses the water out- ward against the bottom of the glass, so it holds the cyclist against the track while he is traveling at a terrific speed upside down

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n of » the ts of tunt. e of acles 1erial r ago > first small ‘lined land form. ghtly ge to ves at 1d oxi- ; leap irst is n the , that stance ike it yehind t itis appa- works or him hysics. ery of ent he health 1eaded y; his ch per- 1 from of ex- wn the eckless redevil din the knowl- _ them, istness, -r out- so it » he is down The master artist of the in- Wasp of the tropics. nest, hung from a twig, is in the form of a flattened ball of dark reddish-brown pulp cu- riously streaked with pat- terns of white, At the side of the nest is a circular entrance This Mason Wasp, called the Eumenid, is a potter of remarkable skill. Above is one of the many-colored jugs of clay in which An ingenious armored house in _the cocoon of a Tropical oth 1s protected from its enemies. It is a silken cone, half an inch high, covered with several dozen thorns made of the finest silk. The cone is hung from a silk thread 10 inches long attached to the apex. It ap- Pears neither to be edible nor to offer good footing, and so is left exquisite he has ever found. where the young wasps are raised, are more delicate than tissue paper. surface of the nest, which is shown four times its actual size, is covered with clay spines POPULAR SCIENCE MONTHLY Masterpieces of Insect HE insect world, like the world of men, has its master architects and builders, its painters and decorators, carpenters, and masons. And many of its odd structures are marvels of econ- omy, safety, comfort, and beauty. In the great South American jungles, where the air is warm the year round, the insects have attained extraordinary skill in the construction of their homes. There are found the masterpieces of their architec- ture, adorned with wonderful designs and colors, and fortified against invading enemies. A few of these structures, photographed by Paul Griswold Howes, assistant curator of the Bruce Memorial (Museum, Greenwich, Conn., are repro- duced on this page. its eggs are hatched Architects a _ protection myriad jungle murderers, the caterpillar of certain species of butterflies pends itself from a leaf by a long, strong thread. Having done this, it weaves a beau- tiful silken basket of deli- cate mesh, less than an inch shows it greatly enlarged This delicate nest of the tiny Trypoxylon Wasp Mr. Howes says is one of the most A huge ‘apartment house’ built by the Social Wasps that live in great communities in the tree tops of Colombia jungles. pulp nest, three feet long, is as tough as the finest papier-maché, beautifully glazed, and as white as Within are tiers of paper In obtaining the nest shown above, the limb supporting it was shot through and the nest dropped The cells of clay The entire outer

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New Vistas of Science The Latest Discoveries and What They Mean to You NEW tool with a most amazing A variety of uses has just been put in the hands of science through the development of a method of producing clear fused quartz in quantities in the laboratories of the General Electric Com- pany at Lynn, Mass. While the material itself has been man- ufactured in small quantities for many years, the new electric furnace, invented by Dr. Edward R. Berry, assistant director of the Thomson research labora- tory of the General Electric Company, transforms it suddenly from a substance too valuable for general use into a material that eventually may become as plentiful as window glass, which it resembles. Unlike window glass, though, fused quartz is almost absolutely transparent; so clear that 92 per cent of light will pass A powerful aid to safe navigation is embodied in the instrument shown above, known as a “submarine oscillator and depth finder,” perfected by Sound waves projected through the water by the apparatus strike bottom ard are reflected back to an instrument on the ship, which records the exact time consumed in the round trip and so computes the depth of water under the vessel. apparatus also determines the distance of another ship, thus greatly aiding the navigator to avoid the danger of collision in a heavy fog research engineeczs of the U. S. Navy. through it. Ordinary glass permits the passage of only 35 per cent, while the transparency of the best optical glass is only about 65 per cent. More important still, unlike ordinary glass, it does not filter out the ultra-violet rays, which medical science knows to be so potent a germicide. And since it trans- mits the heat of light virtually without loss, it makes possible the construction of sun rooms in which invalids will receive the full benefit of the curative rays of the sun while shielded from™ the cold of outdoors. Further, its peculiar quality of trans- mitting light in much the same way that electric current flows through a wire may permit physicians to carry the beneficial ultra-violet rays to parts of the body that usually are inaccessible. If a rod or tube of fused quartz is bent or curved, the light and heat still travel from one end to the other. Unlike glass, the fused quartz, prepared from rock crystals that exist in virtually inexhaustible quantities, does not crack POPULAR SCIENCE MONTHLY from heat, making it an optical material of unusual quality for such purposes as the lenses of telescopes, microscopes, cameras, or moving-picture projectors. New Remedy for Pneumonia ROM the Harvard Medical School recently was announced the discove: y of a remedy which has been used with success in the treatment of many sufferers from lobar pneumonia, who represent about 25 per cent of pneumonia patients. Medical men have expressed the opinion that under favorable conditions the new treatment may reduce the mortality from lobar pneumonia by 25 per cent or more. The The discoverer of the new treatment, Dr. Lloyd B. Felton, is only 32 years old. What he did was to purify the ordinary horse serum, used in the treatment of pneumonia, obtain- ing a white crystalline substance believed to be fatal to the pneu- monia germ. This pure serum does not produce the chills, fever, and “serum sickness’? that more often than not follow the use of horse serum and made it of doubtful value in the treatment of pneumonia. What Bad Roads Cost You T IS obviously more expensive to run an automobile over poor roads than over good ones. Just how much difference it actually makes, though, is astonishing. Taking all expenses into consideration— gasoline, oil, tires, and repairs—motoring over unimproved roads is more than 50 per cent more costly than rolling ove smooth highways. This fact was disclosed in a recent test . conducted by the Department of High. | ways of the State of Kentucky. Sixty-two light cars of the same make and mode | were used in the test, one group being operated for a period on good roads, the other on bad. The upkeep of cars that ran on the good Hm roads averaged 4.22 cents a mile, while each mile on bad roads cost 6.72. In gaso- line alone each mile run over the bad roads @ cost 2.3 cents; on good roads the cost was 1.7 cents. Strange Birds that Bray ATURE’S oddities seem to be without number. An expedition of the Amer- ican Museum of Natural History, search- ing for rare bird specimens in South America, found penguins in the jungle. This was remarkable enough, for pen guins always were associated with the ice wastes of the Antarctic. But these trop- ical penguins bray like a jackass. Another queer find was called by Dr. Frank M. Chapman, leader of the expedi- Dr. E. B. Krumbhaar of the Philadelphia General Hospital, an ex- pert in cancer research work with radium, recently reported that scientists now are able to produce cancer in mice at will. daily applications of isoprene tar on a mouse’s back, he says, result within six months in a wart-like mark that becomes a cancer A few tion, “‘a case of evolution in progress while the species is still in existence.” This consisted of two specimens of the steamer duck, one from inland and one from the coast. The coast specimen lives on crustacea and other small life. It has no enemies and does not have to search for food, so it has forgotten how to fly! It uses its wings merely to aid it in swimming. . § wil ga fue Te Wi

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tion— toring lan 50 y over nt test i High § ty-two fe model | being ds, the e good , while n gaso- d roads ost was ray without > Amer- search: South jungle, or pen- . the ice se trop- by Dr. -expedi- an ex- ed that A few , result cancer progress xistence. ns of the | and one crustacea 0 enemies food, so it s its wings ae Its inland brother, however, must fly above the tall trees to reach the lakes where it finds its food, so it uses its wings as other ducks do. Will the Sun Cook for Us? ARNESSING the sun is an old dream H of inventors, a dream that has ap- proached realization many times through the construction of sun motors, but not vet has been fulfilled. Recently several more or less successful attempts have been made to persuade the sun to render to man additional service beyond the light and heat it customarily supplies. No less a person than Dr. Charles G. Abbot, of the Smithsonian Institution, who is probably the world’s foremost authority on the sun and its ways, was responsible for one of these attempts. At Mt. Vernon, Calif., a few weeks ago, Doctor Abbot constructed a solar cooking range in which he intended to broil steaks and bake bread by concentrated sunlight. Apparently the range was working well— a thermometer test showed a temperature of about 350 degrees within its oven— when some oil was spilled and the stove was destroyed by fire. Doctor Abbot is rebuilding the range, and expects to demonstrate soon that food can be cooked Tubes of clear fused quartz, the most transparent solid known to man, are shown here in the hands of Dr. Edwerd R. Berry. By the perfection of a new electric fur- nace in the labo- ratories of the General Electric Company he has succeeded in pro- ducing umnprece- dented quantities of this extremely useful material, as described on the opposite page POPULAR SCIENCE MONTHLY without coal, wood, Scientists in the Color Laboratory of the Depart- ment of Agricul- ture are conduct- ing researches to produce superior American dyes. At the left is W. C. Holmes, loolzing through a newly perfected machine used to analyze stains Ordinarily, sandstone will withstand a pressure of not more than 8000 to 9000 pounds a square inch. After the sulphur treatment, however, its strength of com- pression is increased to 30,000 pounds, or about 300 per cent. This is due to the fact that the porous sandstone soaks up large quantities of the sulphur. Cement immersed in melted sulphur also has been found to gain remarkably in strength. Tests are in progress to determine how well the sulphur-im- gas, oil, or the other fuels commonly used. At about the same time a San Francisco inventor was demon- strating a solar heating plant in which the rays of the sun, reflected from mirrors and fo- cused through lenses, brought tremendous heat to bear on a small spot. The inventor claimed his apparatus was capable of melting diamonds. Another Californian, utilizing a Somewhat similar prin- ciple, has developed a reflecting apparatus that is said to concen- trate sufficient solar heat to melt the ores of Metals. pregnated sandstone withstands exposure. A Life-Saver NE of the deadliest perils to the mo- torist — the poisonous carbon monoxide gas discharged from the engine exhaust — ap- pears to have been conquered. Dr. Miller Reese Hutchinson, famous inventor and former chief engineer of the Edison labora- tories, announced re- cently the discovery of a chemical compound which, when mixed in small and inexpensive quantities with com- Super-Stone HE U. S. Bureau of Standards has been conducting interesting tests Tecently to supply engineering science with a new building material of tremen- Two views of a new solar furnace invented by Marcel Moreau, Jr., of San Francisco. Multiple mirrors and lenses are used to dous strength, much cheaper than granite. By soaking sandstone in melted sulphur for several hours, it is found that it be- comes as strong as the best granite. concentrate the sun’s rays and develop a heat of 15,000° F. The picture at the right shows the inventor and his father mercial gasoline, not only virtually elimin- ates danger from this source, but prevents carbon deposits in the engine cylinders. An effective mixture, he says, is in the proportion of two or three ounces to five gallons of gasoline.

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40 POPULAR SCIENCE MONTHLY our Meals and Your Health} By Walter H. Eddy, Ph.D. Professor of Physiological Chemistry, Teachers College, Columbia University ARE you afraid to eat lobster with your ice-cream? ‘‘Such an idea is absurd,”’ says Doctor Eddy, expert on ‘‘The dangers in food lie not so much in what is nutrition. eaten as in what is not eaten. “Your food should be palatable,” equivalent to saying that a dietitian’s idea of a good meal The familiar story of a woman losing her husband's love because of poor cooking is more is the same as your own. truth than fiction.” The human body is an engine, the food we eat being the , our strength, and our out- diet. fuel. Our thinking, our work ward appearance all depend upon he says; “which is nutrition. Faulty meals are responsible for more than one half the world’s disease. OT long ago 200 American families N were canvassed as to their diet, and full details obtained of the meals they had eaten through a consider- able period. Almost without exception the diets were deficient in important con- stituents necessary for the support of life. Now, there is no reason why this should be the case. Correct eating is quite as easy to achieve as incorrect eating, and is a great deal more satisfactory to every one concerned. A correct diet produces good health and increases the chance of longev- ity. And yet these desirable ends are not won at the cost of the self-denial that is associated in many minds with the use of the word “‘diet.”’ As a matter of fact, a proper diet is made up of meals that are good not alone because of their physical benefit, but good in the popular sense as well. Moreover, a proper diet does not cost any more, nor require any more work on the part of the person who must prepare the food than does the unscientific ~nd unsatisfactory way of eating that is the rule in so many homes. Most people remember when the popu- lar idea about diet might have been summed up about as follows: Some foods say chicken, vegetables, and cereals— ‘“‘digestible,’’ and hence should be eaten freely. Other foods-—hot bread, for example, pies, hard-boiled eggs, and shellfish—were “‘indigestible,’’ and hence were to be eaten sparingly if at all. Also, certain foods eaten with other foods were supposed to form “bad combinations.”’ Classic examples of this last notion were the combinations of lobster and ice cream or pickles and milk. Either of these com- binations was supposed to lead inevitably to disastrous consequences. were HE experiences of modern dietitians has shown these ideas about harmful food combinations to be entirely absurd. Foods are not antagonistic to one another. There are really no bad food combinations in the sense, anyway, that two foods such as ice cream and lobster form a team that is fatal to digestion. If any one ever really became ill after eating ice cream and lobster, it was be- cause he ate too much or was poisoned by impurities—either one of which might have happened to him after eating ice cream alone, or lobster alone. If there are bad food combinations, they are made so more because of what they lack than because of what they contain, and these become good combinations as soon as you supply the elements that they lack. Or, to put it in another way and show how simple this whole diet question really is in its practical application, there is nothing wrong with the foods you are accustomed to eat, except that, if you’re like the vast majority of people, you probably do not eat those foods in the proportions and amounts required by the chemistry of your body. To take a specific example, a dinner consisting of broiled steak, fried potatoes, bread and butter, pumpkin pie and coffee probably would impress you as being a good meal. It would satisfy your appetite and supply you with enough energy to do your work. And yet, although not so im- perfect a meal as others I might mention, it is not actually a good one, for it lacks at least one element essential to the welfare of the body. Add a green vegetable— spinach, string beans, or something of the sort—or a salad, and you have supplied the element that is lacking, and have made it a satisfactory meal. [>" E reason for this is that your body requires a small amount of mineral salts each day—particularly salts con- taining calcium and phosphorus. These FLUIDS 5918 GALS BREAD 27 2 TONS are present in green vegetables and milk in proper proportions. Now, except for the small amount of milk that probably would be placed in the coffee, or would be used in making the pie, until a green vegetable was added, the meal I detailed above was lacking in the calcium, which is of especial importance in the promotion of bone growth. This was the principal deficiency shown in the 200 diets to which I referred above—a lack of green vegetables and milk. And it is the un- For years Doctor Eddy has been studying human beings and the food they eat. tion by isolating “vitamin D,” one of the mysterious and elusive vitamins so essential to the support of life. In the article beginning on this page he outlines in a simple, understandable way the scientific principles of He translates the calories, vitamins, proteins and carbohydrates of the dietitian’s laboratory into plain, non-technical language. Doctor Eddy shows you how to eat what you like and yet promote your health and happiness. say is important to every reader of this magazine. Recently he attracted wide atten- What he has to —Tue Eprror. doubted reason why so many children in a this country are afflicted with rickets, and why so many people have bad teeth. HE first purpose of food is to supply the body with energy in the form of heat. This is measured in calories, just as coal is measured in tons. Getting the proper amount of calories each day, hovw- ever, does not solve the food problem. Restaurants and cookbooks frequently give the number of calories certain dishes contain, but that doesn’t mean every: § thing. Any food chemist could compilea § “‘diet’’ consisting of alfalfa, chicken com and linseed oi! that would contain all the calories the human body requires, but you couldn’t use such a diet. The human body is not designed to digest and utilize hay and linseed oil. The human body, however, is de signed to digest and utilize food of the kind you always have been accustomed to eating, and it is from those foods that you must select your diet. stitutes; carbohydrates, that is, and foods of a starchy sort, such as potatoes; fats, and mineral salts. Showing the amount of staple food consumed by the average man in his lifetime. People of the United States spend $49,- 000,000 for food daily MEATS 18.3 TONS FISH 6.6 TONS EGGS- 15,000 selection from among these four elements solves the problem of proper eating, One trouble with Americans they may seek to supply their bodies with energy from proteins alone. They may eat too much meat. ; You may apparently thrive on a diet containing too much meat for many yeals, but such a diet is almost certain to lead t0 dangerous disorders, for it causes an aa condition of the body that may accelerate rheumatism, premature old age, hardet Science im divides those foods into four classes— fs proteins, which are meat or meat sub- 9 sugar jam Propet is that §

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\ildren in kets, and peth. to supply e form of ries, just stting the lay, hovw- problem. requently ain dishes in every: compilea cken com uin all the s, but you ie human nd utilize r, is de od of the -customed foods that Science classes— neat sub- is, sugar § - such as s. Proper iount of imed by 1 in his » of the ond $49,- ds daily r elements er eating. s is that yodies with They may on a diet any yeals, 1 to lead to ses an acid accelerate e, harden 4 ing of the arteries, and even apoplexy. The amount of meat thatshould beeaten in one day by the average person should not exceed the equivalent of half a pound * of beefsteak, and you probably will find one meat meal a day sufficient. Or you may get the amount of protein your body needs in a day from any of the following: two quarts of milk, six eggs, or a third of a pound of cheese. HIS daily allowance of protein may be said to supply the nucleus of your diet. Add to it fats, carbohydrates and mineral salts in amounts sufficient to form meals of your accustomed size, and your diet problem is virtually solved. The one precaution to he taken, though, is to avoid excessive eating of fats and carbohydrates. Americans are not likely to overeat on fats, but many persons do eat too much sugar and starches, which ferment in the stomach and cause head- aches, physical sluggishness, and other ills. In fact, there are many persons who probably never have tasted strong drink in their lives who actually are suffering from an _ intoxica- tion similar to that produced by alcohol, due to injudicious eating of sugar and starches. This sort of food intoxication has all the narcotic effect of whisky without its exhilara- tion. fy A simple way to avoid the \e danger of overindulgence in y3 starches and sugar is to use Na green vegetables to supply much of the bulk of the food A you are accustomed to take POPULAR SCIENCE MONTHLY from potatoes, bread and similar starchy foods, and to substitute cooked fruit, simple puddings and ice cream for pies, pastry and other heavy desserts. Milk also should be taken regularly. It need not necessarily be drunk, but can be used in cooking. Your food, of course, should be palat- able, which is equivalent to saying that a dietitian’s idea of a good meal is the same as your own. The familiar story of a woman losing her husband’s love because of poor cooking is more truth than fiction. In fact, I am certain that a great deal of domestic unhappiness would be eliminated if women understood that a man doesn’t consider dinner without dessert areal meal. URING the late war I served as major in charge of food resources with the A. E. F., and I know that one of the most potent factors in upholding the morale of the American army was the variety of food supplied the soldiers in their ordinary rations, particularly in the matter of desserts. Dr. Walter H. Eddy, authority on diet and nutrition, at work in his laboratory at Teachers College, Co- lumbia University, where he recently suc- ceeded in isolating vitamin D 41 Another important point in the selec- tion of the diet, and one which most per- sons are inclined to overlook, is the necessity of including food that must be chewed. The white meat of chicken and potatoes and white bread are palatable and digestible, but their fibers are not strong enough to supply the “roughage” which is necessary to intestinal digestion. (Continued on page 115)

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POPULAR SCIENCE MONTHLY ’ H Goi, © | MAME 4 Pe a Efficiency of Workmen Revealed in Movies HE superior technique of workmen who do more in less time than their fellows is being recorded on motion- picture film by efficiency engineers, using a plan invented by Frank B. Gilbreth. Against a background marked off in squares so that it looks like a magnified piece of graph paper, the workman goes through a job in his best manner. Beside him is a clock with a single hand. This hand moves so rapidly around the dial that each of 16 film pictures taken in a Handy New Tire Deflator Clamped to Valve Stem HE handy automobile tire deflator illustrated above has been designed primarily to save time in doing tire repair work. Usually to deflate a tire it is necessary to press the prong of the valve cap, or other similar object, against the valve pin until all the air has escaped. The new deflator, however, is clamped to the valve stem simply by a slight pressure of thumb and finger. In this position a small pin in the center exerts continuous pressure on the valve pin, compressing the spring. This leaves the hands of the worker free for other jobs, such as assembling repair tools, while the tire is being deflated. SKIN from a patient’s arm was used to unusual performed at the make him new eyelids in an operation recently Liverpool Royal Infirmary, England. second shows it in a very different po- sition. The squares of the background, as they appear on the motion-picture film, serve as guides for exact measurement of dis- tances covered by the larger movements of the workman, while the speeding hand of the clock reveals the exact time consumed by each operation that goes to make up the work. Thus waste movements and movements ordinarily made too slowly, are revealed. Seven Tractors Move Huge Boiler Four Miles EVEN Ford tractors, five in front to do the pulling, and two behind to serve as brakes on down grades, hauled a 40-ton boiler recently from the Govern- ment Printing Bureau, in Washington, D. C., into Maryland. The distance, four miles, was covered in 105 minutes. Not even on the several rather sharp up and down grades was difficulty en- countered, although the braking ma- chines in the rear proved to be invaluable aids. The boiler rested on two large wheeled beds. Flexed Steel Band Plays Music for Dancers A NEW musical instrument, capable, it is said, of a surprising variety of ‘jazz”’ effects, is making its appearance in American dance halls. It can play solo or accompaniments, and is said by those who have heard it to be an effective addition to a trap drummer’s repertoire. This unique instrument is a steel band against which two hammers strike. The Top and side view of the new musical jnstru- ment, showing how tones are produced by striking steel with hammers degree to which the band is flexed by the player’s thumb determines the note played. The tone is described as a clear, flutelike, singing whistle, with a tremolo. Loud or soft music can be played. A scale at one side guides the player. The idea embodied is a modification of the vaudeville ‘‘musical saw.” It is claimed, however, that a much greater range of tones is possible with the new instrument anc that one can acquire fair proficiency quickly. ‘‘Doorless Door’’ Bars Flies 7° TEST the efficiency of a newly in- vented ‘“‘doorless door,”’ designed to keep flies from entering meat and fish markets, 2000 house flies recently were imported from Dallas, Tex., to Boston, Mass. A _ screen of air from hidden electric fans above and below the door is used to bar the flies. SS a Five tractors hauling the 40-ton boiler. Two tractors in the rear acted as brakes | ‘ | v “ ae ae ee ee —— |

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ays apable, ‘iety of ance in solo or those ffective ertoire, and side f the new al instru- showing nes are ced by ag steel hammers by the / note . clear, emolo. od. A or, ication It is rreater 1e new ire fair Flies wly in- ned to id fish y were soston, hidden » door Camera ‘“‘Gun’’ Is Mounted on Rifle Stock EAL hunting without killing—un- usually fine photographs in place of dead game. This new brand of sport, re- quiring skill in marksmanship, is available now, it is said, with the perfection of an accurate camera gun made by mounting a standard aerial camera on a rifle stock. “The invention, originally developed for use by army observers, is rapidly be- coming popular among amateur and pro- jessional photographers. A turn of a crank at the side of the box winds the film and sets the shutter. A pull on a trigger makes the exposure. Traffic Signal Bends Over if Struck by Auto \ OUNTED on a ball-and-socket joint + in the pavement, an ingenious new traffic signal gives at the instant of im- pact, allowing the ear hitting it to pass safely over. It was invented by Frank Griswold, of Minneapolis, Minn., as the result of a collision with a stationary sig- nal one stormy night more than four years ago, in which the inventor barely escaped death. The signal is a slender pole, five feet six inches tall, anchored in its socket by six powerful coilsprings, which right it when it has been overturned. Its lights con- =~ to operate even when the pole is cnocked flat. POPULAR SCIENCE MONTHLY { Lj j i j ‘ fo” “Turntable Home’ HE “turntable house,’’ one of the world’s newest ideas in home con- struction, has been originated by an architect in Berlin, Germany. Designed for the purpose of economizing in space, it is said to convert a single large room into several different rooms that are available for use as desired. Each floor of the two-story house has one large room, at one side of which, con- ’ Has Many Rooms in One cealed by draperies, is a turntable divided in three sections. Each section, sepa- rated from the others by walls, is a room in itself. Thus, one section, furnished with a piano, may serve as a music room, an- other may be a card room, and the third a bedroom. The photograph above shows the turn- table, with two of its sections, being pushed around by a child. When the Shoe Pinches wo people claim their corns warn i them of weather change. But prob- ably the corn merely is registering change in the shoe leather. This varies with the amount of moisture in the air. A two per cent change from normal either way is about all the average foot can stand with- out discomfort, according to a recent report of J. A. Wilson to the New York section of the American Chemical Society. He cited experiments to show that the amount of pinching varies with the kind of leather used. Se aed PG dea Struck by car, the traffic signal bends and the car passes over it A Pocket Clothes Brush N OVING a small lever causes the bristles of this pocket clothes-brush to lie flat, so that the entire brush can be carried in a case Jess than half an inch thick. In the photograph above the lever is shown at the left and the thin metal cover of the case at the right. Stature and Disease HYSICIANS at the Presbyterian Hos- pital, New York City, have reached the conclusion that the presence of dis- ease, or at least a predisposition to certain diseases, is indicated by the size and shape of the body. Measurement of many patients suffering from several common ailments showed, it is said, that each ail- ment has its distinct bodily type. About 85 separate measurements were made on each individual.

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POPULAR SCIENCE MONTHLY 4 5 4 ag Z p ee 4 “s 4} 3 j ; , «ag } Y Waal: Gia 1% ye i; a f i " = . ii H ; oe inde Mle 4 i tens Loe fo ————— Fee: : = >————— gee p S| , fe es zA ee. : tf le Mies — ‘ie me Hi Be gsi i LEY ZH; J Q ~~ i Koen 4 “4 gee pee Washes and Sterilizes 900 Dozen Eggs Hourly GGS are washed, rinsed, dried, steril- ~ ized, and dry-cleaned at the rate of 900 dozen an hour, by this huge machine with which seven girls are said to do as much work as 40 girls did formerly, and which is designed to re- duce breakage 75 per cent. The machine is fed at the left end with trays, each containing 36 eggs. The upper portion washes, rinses, and dries them. Those to be sterilized are carried to the lower portion. The sterilized eggs then are freed of gloss by reciprocating brushes. The machine can be used as a cleaner alone, or as a sterilizer, as desired. A Universal Socket Wrench for Ford Cars RACTICALLY every nut and bolt on a Ford car, it is claimed, can be gripped with the universal socket wrench pictured below. Eleven different sizes of nut and bolt are provided for. Each size of socket js exact, a feature that prevents the round. ing off of nuts. Unscrewing hub cap with the wrench Automobiles Tested EVOLUTIONARY changes in the design of motor-car bodies are ex- pected by some automotive engineers to result from experiments in progress at the Kansas State Agricultural College, to de- termine the best means of minimizing wind resistance. Two unusual pieces of apparatus have been designed for the experiments—a floating platform and a wind tunnel. The platform is atop a hill, exposed to a clear sweep of wind, and is built on the top of a tank 16 feet in diameter that floats in a second tank partly filled with water. Four stay-ropes prevent side sway of the float. Floating platform and wind tunnel ~ tests Tiny Pencil Is Carried in Finger Ring \ OMEN often have no convenient way of carrying a pencil. Men, too, often find themselves without one, despite their numerous pockets. But every one can carry a ring, and a ring is not lost easily. This newly patented ring conceals a tiny refillable pencil. The pencil folds back under an oval or oblong of black onyx. A notch holds it firmly when in use. Turning a screw pushes the lead down as it is worn off. The stone is mounted in a silver setting on a silver ring. Beast, Bird, or Fish? A STRANGE bird that is reported to look like a bat, swim like a fish, and break rocks with its bill, is one of the curiosities sought by a party of Uni- versity of Pennsylvania explorers, who recently embarked on an expedition to the Amazon, South America. They hope to obtain motion pictures of the creature, which is called the “‘hoatzin.”’ for Wind Resistance A car is driven on the platform, headed toward the wind. Instruments then measure precisely the drift of the float before the wind. The wind tunnel is used to supplement the findings obtained by the floating platform. In it the wind, produced by an airplane propeller, is unchanging. The car being tested is driven into the tunnel on a platform. The portion of the tunnel occupied by the car is enlarged according to careful calculations, so that the car will not increase the air speed. The push of the wind against the car is measured by determining the pull re quired to return the platform to the position it occupied originally. A specially designed fan, capable of bearing 17 tons of centrifugal force upon each blade, is being built to replace the airplane propeller. the be: uni ab] of tal cer as wa the his pla mi Abo pow that gers Side frau. is 1 Pict The Cate:

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nch olt on an be Tench 1 bolt ‘ket is ‘ound- nch we ~ headed 3 then e float ylement floating ced by anging. nto the j 1 of the nlarged so that speed. the car pull re- to the able of pe upon ace the Tiny Spotlight Attached to Band Instrument Fics to the lyre of any band instrument, this device—an arm extending toward the mouthpiece and ending in a tiny spotlight—throws a strong light directly on the music score to be played. A battery concealed in an attractive case behind the music rack feeds the light. Any width of rack can ° be accommodated. POPULAR SCIENCE MONTHLY ry - Builds Wheelbarrows with Pneumatic Tires HESE odd, shock-absorbing wheel- barrows, equipped with pneumatic tires, were designed and built by N. E. France, a beekeeper of Plateville, Wis., for the purpose of transporting his bee- hives without disturbing the honey- makers. He says the carriers can be used advantageously for other purposes, such as transporting eggs without danger of breakage, using either bicycle or auto tires. Railroad Conquers High Peak of the Alps NVALIDS and others who have not mountaineering legs now can ascend the Jungfrau (one of the most famed and beautiful peaks of the Swiss Alps) on a unique railroad that exemplifies remark- ably the resourcefulness and ingenuity of modern engineering. The feat has taken nearly 30 years. The road owes its existence to an as- cension of the peak some years ago by a Swiss engineer, A. Guyer. So charmed was he by the tremendous panorama and the great chain of mountains, that on his return to his hotel he drew up a rough plan for the project, working until after midnight As most of the ascent lies within the $e Above: One of the Powerful engines that haul passen- gers up the steep Side of the Jung- frau. The engine 18 stripped in the Picture. At right: The mountain train catering the tunnel region of perpetual snow, that part of the road could not be built outside the mountain. The frequent avalanches and great depths of snow would have made it too dangerous. So the engineer arranged to bore a long spiral tunnel, keeping close to the sides affording the best views and breaking openings at intervals. The entire length of the road is six miles, 414 of which are in the tunnel. A special spur gear track is used to insure safety, some of the grades running as high as 25 per cent. The highest station is 11,300 feet above sea level. The 18-ton locomotives that haul the 35-ton trains up are among the most powerful ever built. They are electric, driven by two 350-horsepower motors. Four sets of independent mechanical brakes are on each locomotive. Three are hand-operated. The fourth is auto- matic. On the down trip the locomo- tives are used to generate electric current, which is fed back to the power “3 station. Safety-Razor Blade Holders Permit Easy Stropping AFETY-RAZOR blades, single or double edged, can be stropped just like the veteran straight-edge razor with this new device. The blade fits in a holder that in turn is held tightly in a slot by the stropper. Two holders, said to accommodate be- tween them every kind of safety-razor blade, are provided. An ejector attach- ment is provided also. Blades can be inserted safely, quickly, and easily. RECENT excavations in California brought to light two tools—a petrified bone awl about two inches long, and a rudely fashioned quartzite palm-ax. Dr. William A. Bryan, director of the Los Angeles Museum of History, Science and Art, announces that the tools prob- ably were used by the prehistoric men whose petrified skeletons were found near-by, believed to belong to the Pleis- tocene era, ending some 25,000 years ago.

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IQUID soap is thrown away every — time a holly wreath goes to oblivion with the ashes and tin cans. That potential liquid soap is thrown away, for it can be made from holly leaves. So also ean 11 other by-products, including animal food, medicinal tablets, confec- tions, cigars, and champagne, the two last said to be deceptive imitations. The production of this astonishing is, POPULAR SCIENCE MONTHLY ee Imitation Tobacco and Soap from Holly assortment from Christmas greenery is the result of 12 years’ experimenting by Stephen M. Hoye, of New York, lawyer by occupation and chemist by avocation. Tirelessly and with huge zest, he has dedicated most of his leisure hours to this chemical necromancy. His latest feat is imitation tobacco. The buckthorn is removed and the re- mainder cured, bleached, and flavored. Fourteen Views of Eclipse Taken on One Plate [& REMARKABLE photograph, show. fmm / ing 14 different progressive views oj 4 the last solar eclipse, was taken by Victor: sa H. Van Horn, a professional photographe, Jim ti of Three Rivers, Mich. mona All the exposures were made on the one photographic plate. The first was fir made at 3.22.30 p.m. and the last a ie 4.27.30 P.M., a five-minute interval being allowed between each of the exposure, Every exposure was timed at 14/100 of. 8 second. Progressive view of a solar eclipse Full-Size Microscope Folds into Pocket Length FOLDING pocket microscope, pow- erful enough to make blood counts and detect minute botanical structures, is now available for physicians, scientists, and students. Although, extended, the instrument has a standard length tube, it folds into a ease four inches long and three inches wide: It has a special invisible objective, with a focal length of six millimeters when used complete and 12 with the front element removed. Light is reflected by an inclinable mirror and a condenser. Ice-Age Grasshoppers Found in Glacier N ILLIONS of grasshoppers that died during the Ice Age, some 500,000 years ago, are buried throughout a big glacier on the north flank of Mount Wise, near Yellowstone Park. The _ clean, glittering ice alternates with dark bands of frozen debris. In this debris, and on the glacier surface are frozen these myriads of mummified insects. They lie, for the most part, in layers. Rangers of the park, particularly a girl ranger, Miss Margaret Lindsley, have been active in procuring specimens and investigating the extent of the find. They have found this hard and perilous work, it being necessary to cross a glacial lake that is set at the foot of the glacier by leaping from ice cake to ice cake. A number of perfectly preserved speci- mens have been found. These seem vi: tually the same as modern grasshopper ; when placed side by side. a Scientists, attracted to the park by we reports of the phenomenon, subscribe toi the theory that the insects, coming ini¥ ( great swarms from their breeding ground} across the Bear Tooth Mountains, werfim [| driven to the ice by sudden storms ani there frozen in, to remain in a state cfm | almost perfect preservation for half 2% million years. As a result of the wonderful find a the side of Mount Wise, the glacier has acquired a name of its own—it is now . known as “Grasshopper Glacier.” Al ready tourists are including it in ther itinerary of a trip to Yellowstone, though the glacier lies outside the park proper. Below: One of the mummified grass- hoppers found in the Mount Wise gla- cier by the million. Scientists think they are probably relics of the Ice Age, an age that geologists place at approximately half a million years ago Miss Shaw and Margaret Lindsley, the latter a ranger of Yellowstone Park, digging out bodies of 500,000-year-old grasshoppers from Mount Wise glacier at t

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Llipse This Finder Indicates Any e . Star Instantaneously , show. NY important star or constellation riews of £4 can be located in a moment, it is r Victor said, with this new finder. The constella- grapher tions are named on a dial and beside each name is a dot diagram of the group. on the To locate a constellation, one places the rst was finder on a level surface, the face to the last a north. The sliding pointer is adjusted to al being indicate the date, and the movable dial is posures, adjusted to show the hour. The pointer 100 ofa with the open center is moved so that the name and number of the constellation sought are seen through this center. Properly adjusted, this finder indicates any star desired The arrow then is moved up or down until the number on the arc corresponds to the number within the pointer. The arrow now points to the constellation. Directions list the stars in each con- stellation, showing how to find them by the dot diagrams on the dial. er seem Vil sshoppers park by oseribe to oming it g grounds ains, welt corms and | a state o! or half 3@ il find on lacier hasf -it is now ier.” Ak t in ther ne, though rk proper. ne of the -d grass- found in tWisegla- 1e million. think probably the Ice age that ; place at ately half years ago — = QO TEST the resistance of window a. to flames, the Underwriters’ o atories use a gas furnace in which a go of 1800° F. is maintained for alfan hour. The wire glass windows are ‘tin a frame in one of the walls of the brick furnace, as shown in the picture at the right, POPULAR SCIENCE MONTHLY pla bisraih pai jee yf pees wees es Z A Bacteria Earn Board in Health Service | allenggatin have their own boarding- house, run by the Public Health Ser- vice, at Washington, D. C. Although the menu always is soup, and nothing more, it is by no means the watery soup that is supposed to be characteristic of boarding- houses. Steak, eggs, potatoes, gelatin, and milk are among its ingredients, and the 60,000,000,000,000 small boarders are said to grow plump rapidly on it. Tables being considered not feasible, the bacteria dine in tubes, in intimate little groups of 10,000,000,000. This makes it necessary for L. J. Bender, their chef, shown inspecting one of these groups, to supply soup to 6000 tubes daily. The “boarders” earn their keep by Glass Windows Tested in Blazing Furnace In this way conditions that might be encountered in a burning building are duplicated. Glass that disintegrates with the first hot blast not only would be dangerous in case of fire, but would create a draft that would spread the flames. the laboratories. assistants in Service’s serving as research Public Health New Lignite Process May Lower Coal Bills | JGNITE is transformed into a fuel claimed to possess the heating quali- ties of anthracite coal by this new oven, perfected by the United States Bureau of Mines. Lignite—primeval wood prevented from becoming coal by the excess of water in the earth surrounding it—underlies great areas of the Northwest. The Bureau estimates the cost of producing it at $8.17 a ton. The oven is essentially a vertical shaft with a top opening through which the raw lignite is supplied. Carbonization is effected by maintaining a combustion zone in the middle of the shaft and passing the lignite through it slowly enough to maintain a state of bare “combustion. This is accomplished by supplying air under slight pressure. Varying air pres- sure and the rate at’which the carbonized fuel is discharged regulate the degree of carbonization. The carbonized lignite is in the form of char, which usually must be briquetted. A ton of lignite yields 42 per cent char.

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a FOPULAR SCIENCE MONTHLY HESE two books—one said to be the oldest, the other the smallest in the world—are on display at the University Library in Philadelphia, Pa. The oldest book——about an inch and a half square is a record of commerce and barter in- scribed on stone during the Ur dynasty of The World’s Oldest and Smallest Books the Babylonian kings, more than 5000 years ago. of the hand above. The smallest volume, made only a few years ago and containing several hundred pages, rests in the hollow of the hand as pictured above. World’s Largest Bell for Cologne Cathedral HE largest bell in the world, a mag. nificent modern example of the bell. maker’s exacting and historic craft, was completed recently for the tower of the famous Cologne cathedral, in Cologne Germany. The ornamentation of the great bell, although simple, is said t have been wrought with rare artistry. Its ancient predecessor in the old steeple was removed during the Great War and melted for use as metal for munitions In the photograph below workmen are shown moving the bell on rollers by means of block and tackle. It is shown between the fingers Moving the huge bell on rollers ss & — . aves One-Sided Ship a Landing Field for Aircraft HE something that seems to be miss- ing from this ship never was there. he vessel is the British naval aircraft carrier, Herines, and the flat, open space is a landing-deck for the seaplanes she mothers. The superstructure has been com- pacted into a five-story starboard tower. The craft is ballasted heavily to port to compensate for the weight of the tower. Exhaust from her engines escapes through horizontal funnels at the stern. The Hermes is said to be the finest craft of her type in the world. MOLES may be controlled by placing tea- spoonful quantities of concentrated lye in their runways at 25- and 50-foot intervals, recent experiments indicate. Shopper’s Pencil and Vanity Case Combined ESIGNED especially for the woman shopper, an unusual combination of pencil, powder puff, and rouge stick is handy either for jotting down shopping notes or for renewing the complexion. While the by removing a cap, which contains a day’s supply of powder. In the lower part of the holder is another compart- ment with an extra supply of leads for the pencil. pencil is small enough to be carried in a compartment of a small hand- bag, the upper part of the holder serves as the vanity case. Powder puff and rouge are made available The pencil with cap removed, showing powder puff and rouge “Auto Grasshopper” Survives Hard Bumps A” EMBANKMENT at a danger- ous turn in the road probably would hold no terrors for a newly invented automotive ‘“grass- hopper’? shown below in mid- air during a six- foot jump. The car, the ingenious crea- tion of a French engineer, has extraordinarily powerful springs, so that even a hard fall cannot smash it if it lands up- right, the maker ©K.&H. claims. Also, it is said to be fire proof, so that a bad crash could not set it ablaze. Although the car seems to lack an engine, it has one, just in front of the rear wheels. It is the inventor himself who 1s shown in the picture below handling his acrobatic car. Making a six- foot jump from an em- bankment in the new shock - proof automobile A brill pair exte rece of rese cont B his $ Mu: — “ It i: fore E fligl bird flow atec He T acec Hea com apo’ pne sub: FE! can who fron affo: carr mar to x

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Model of a da Vinci Plane Built from His Plans ALTHOUGH for centuries it has been mag. [\ known that Leonardo da Vinci, e bell. prilliant medieval engineer and renowned for t, Was painter of the “Mona Lisa,”’ had made of the extensive researches in aeronautics, the logne, recent discovery in an Italian monastery of the of parchment records of many of his 21d to researches was the modern world’s first ry. conerete knowledge of them. e old Below is pictured a model from one of at War his sketches, built recently at the National ‘itions, Museum of History, at Washington, D.C. en. are —— rs by Model built from da Vinci sketch It is an impressive witness to the creative foresight of the great artist. Da Vinci approached the problem of flight by analyzing the equipment of birds. This model is designed to be flown by the flapping of the wings, oper- ined tains 2 ated by a pilot lying prone on the frame. e lower om part- ads for (9 Healthiest Year on Record HE last year has been the healthiest — year on record in the United States, | fm according to statistics of the U. S. Public Health Service and leading insurance companies. Tuberculosis, heart disease, apoplexy, Bright’s disease, influenza, =| pneumonia, and diabetes all showed a | substantial decrease from the year before. gl appreciate how versatile a — a conveyance a motorcycle can be. In Wales, many farmers who live a considerable distance ee Imps from the city and cannot be fire afford to purchase trucks, ‘ould not carry their products to market in crates attached o lack an to motorcycle sidecars. front of Driving a calf If who is to market on the sidecar handling cing a Six- t jump 1 an em- rkment the new ~k - proof omobile Sidecars Carry Farm nga y POPULAR SCIENCE MONTHLY 0S FAIR PRED 1S. Ty. MOLES A ‘THE RATED IPERS MEME [00 MILES AN HOUR TNE EPPWE STATE Kermit Mi 999 POLLED THE FASTEST TRAIN Ih THE WORLD JULY 1492 AT THE CHICAGO WORLDS 5. OER, io kis ts “ ae , i C ITH his knife, Ernest Warther, of Dover, Ohio, for years has been recording the history of locomotive building in wood. His astonishingly detailed carved models have been in- spected by thousands, including admiring fellow carvers, at exhibitions. Even to the fittings of the pipes that run along the body, and to the smallest detail of the How to Flavor Your Coffee HERE is a best way of doing every- thing—even of putting sugar and cream in your coffee. In fact, to put sugar and cream in your coffee is quite wrong, according to the dairy experts of the U.S. Department of Agriculture. The correct procedure, they say, is to put cream in the cup, then the coffee, and add the sugar last of all. from ‘‘feathering’”’ should it be slightly sour. Coffee poured on cream and sugar in a cup is almost certain to result in the cream’s curdling. Products to Market Even a partly grown calf, as the picture shows, can be transported conveniently. It will be observed also that besides the calf, the sidecar is carrying a smaller crate just in front. arves Wood Models of Famous Locomotives This will prevent the cream couplings, his wooden miniatures are faithful reproductions. His collection now includes models of most of the famous locomotives that have marked epochs in the development of steam transportation. These range from Sir Isaac Newton’s tiny locomotive to the famous ‘‘999,”’ holder of the world’s loco- motive speed record, 121.3 miles an hour. Radio through 120 Feet of Solid Rock | aoa waves can leap through 120 feet of solid rock about as swiftly as through free air. This was demonstrated recently at Rocky River, Ohio, when a receiving set placed that distance under- ground in a mine shaft picked up con- certs from local and distant stations. The set was used with a highly direc- tional loop. Because the tunnel at no point was higher than 5)4 feet and aver- aged four feet in width, the sides and roof exerted a marked ground capacity. This was overcome by swinging the loop parallel with the mine shaft, proving that the radio waves heard were pene- trating the rock, not entering the mouth of the tunnel. A loudspeaker was used. Local sta- tions came in very loud, and many dis- tant stations were heard faintly.

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50 New Motor Fuel to Silence Knocks Y THE middle of this summer you will be able to purchase at ap- proximately 30,000 filling stations in various parts of the country, a fluid that will double the efficiency of your automobile, eliminate the troublesome motor knock, and give you 100 per cent greater mileage in addition, according to engineers of the General Motors Research Corporation, inventors of the product. This liquid will be mixed in small quantities with your regular gaso- line, at the additional cost of three cents a gallon over the current price of gasoline, it is announced by authorities on fuel. The name of this new product is ‘fethyl gas,’’ a combination of commercial gaso- line and tetra- ethyl-lead. It is the fruit of seven years of research in which chemical engineers sought a fluid that would increase the effi- ciency of the gaso- line motor. For a long time it has been com- mon knowledge among experts that only five per cent of the _ in- herent power of the fuel used in internal combus- tion engines ordinarily is utilized by the motor; that the other 95 per cent is wasted through the exhaust pipes; blown into the air without doing a bit of useful work. To reduce this waste, de- signers have known that it is necessary merely to increase the power of the motor by increasing the compression, but they also have known that when this is raised beyond certain well de- fined limits, the engine begins to knock. ECOGNIZING that the stan- dardization of fuel composi- tion was one of the necessary achievements toward realizing the perfect motor, the engineers of the General Motors Research Corporation at Dayton, Ohio, set out to discover the cause and prevention of the gas knock. After careful investigation they learned that the knock is caused not by pre- ignition, as was generally supposed, but by the creation of a high velocity gas wave in the combustion chamber, due to certain imperfections in present-day gasoline. This wave, striking against the piston or cylinder head, causes the knock, which actually is the result of detonation. Searching for a remedy, they added various chemicals, singly and in com- bination, to commercial gasoline in an effort to find a fuel that would eliminate the high velocity gas wave. Approxi- mately 2500 substances were tried and One of the engines with electrical apparatus used to test the new ethyl gas and other fuel combinations. On top of the engine cylinder POPULAR SCIENCE MONTHLY By Robert E. Martin discarded because of excessive expense, corrosion in the motor, offensive odor, or other drawbacks. Finally it was dis- covered that tetra-ethyl-lead would pro- duce the desired results. The solution had been found! But alas, a pound of the precious fluid cost $585, and the amount necessary to ethylize six gallons of gasoline—which cost a few cents a gallon— would cost six dollars! Three years more of ex- perimenting and the test- glows with every This attachment to the filling station appara- tus mixes ethyl fluid with gasoline as it is dis- pensed. The device has a crank, each turn of which releases just enough of the new knockless fuel to treat a gallon of gasoline ing of additional thousands of schemes finally produced a means of producing tetra-ethyl-lead commercially for 121% cents an ounce—an amount sufficient to ethylize six gallons of gasoline. The re- maining problem now was that of market- ing the new fuel, which was solved in this way: is an apparatus connected with an electric 5 P light, shown in the case at the left, that which fuel is con- explosion of the fuel The basic supply of ethyl fluid is th Du Pont Chemical Company at Wi. mington, Delaware. The product ; shipped to Dayton, where it is blended in a special department of the Generg Motors Corporation and prepared fo; shipment in sealed cans. These ar standard sized containers that hold fiy liters, sufficient to ethylize 1000 gallon; of gasoline. - yr 4 s708 dispensing, the ethy] js iy poured into a specially de tached to filling station apparatus, allowing the pump to be used for standard gasoline or ethyl gas. One revolution of the little crank on the side of the ethyl container liberates enough fluid to gasoline. Ethyl does not produce high test gasoline from a medium test prod- uct, nor add power to the gasoline proper. It simply changes the conditions under sumed in the mo- tor. Demonstrations are reported to have proved conclusively _ the beneficial effect of the addition of tetra-ethyl-lead to gasoline. A single-cylinder engine running at about 1000 revolutions a minute first was used in the tests. It ran smoothly on com- mercial gasoline, carrying about 80 pounds compression to the square inch. The addition of kerosene to the tank developed a severe knock and the amperage shown on the dial dropped from 25 to 17.5. The addition of a small quantity of ethyl fluid at once removed the knock and brought back the amperage to its original figure of 25. N SEVERAL standard automobiles the normal compression of from 60 to 90 pounds was raised as high as 160 pounds to the square inch, which, under normal conditions, would produce violent knocking.’ With ethyl gas these cars climbed steep grades in high speed at less than 10 miles an hour without even a trace of a knock and without the slightest injury to the engine. What will this discovery mean to the motorist, to you and your neighbor? If general usage substantiates preliminary demonstrations, it will mean that the efficiency of your present motor will be doubled; the power that may be obtained from gasoline resources will be doubled, the life of your car engine will be length- ened and the operating cost will be cut. signed vending mechanism at. § treat a gallon of § does it § Ps Py og # 4 i b 2 x i"

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<§ is the t Wil uct js ylended yeneral ed for se are ld five gallons thyl is lly de sm at- filling aratus, e pump ed for rasoline s. One of the on the e ethyl iberates uid to illon of @ oes not igh test rom a st prod- does it @ to the oper. It nges the 3 under is con- the mo- orted to aly the addition rasoline. running tions 4 in the on com- g about to the ition of eloped a mperage ed from on of a fluid at ck and rage to omobiles ym 60 to as 160 h, under » violent ese car\rs speed at put even out the n to the bor? If liminary chat the - will be obtained doubled, e length- | be cut.

POPULAR SCIENCE MONTHLY Better Tools for the Housewife

Worn and shiny garments can be renewed, it is said, with this rotary device con- taining thousands of tiny needles with microscopic hooks that bite into the fabric and pull up new nap

for thread.

The unattractive chain switch for elec- tric lights that often rattles against large shades can be eliminated with this ex- tension, easy to install and to operate

Broken corks are readily pulled with F this device. The Spring prongs are inserted so that the cork is between them and a twisting motion withdraws it from the bottle

F2 This compact sewing kit, 234 inches long, contains fv thimble, pins, a variety of needles, and two bobbins The metal case is said to be rustproof

Grasping the split handle of this iron causes the legs of its metal stand to fold up out of the way for ironing, as shown above. When the top half of the handle is released, a spring causes the supports to spring back, as at right. Various sizes are made The broom shown at the right has two sweeping ends. When one is worn, the other is brought into service by re- versing the head

51

A newly invented high chair becomes a baby carriage when folded down, the tray being removable. The carriage is equipped with a safety brake

A marble rolling in an inclined slot- ted cylinder grips the broom handle firmly in the simple holder shown at the right

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POPULAR SCIENCE MONTHLY The electric bench machine with rotary saw attachment, used in cutting lumber Weighted Strap Supports Ash Receiver VERY housewife who has had to clean tobacco ashes from the rugs knows by sad experience the trouble that is caused whenever an ash receiver topples from its precarious perch on the arm of a chair or davenport. To prevent just such accidents there has been invented a decorative weighted strap designed to serve as a convenient anchor. The strap is weighted at each end, while the receiver is attached to it at the center by means of a spring clip. When the receiver is to be used, the strap merely is thrown over the arm of a chair, where it holds the receiver firmly without danger of spilling. When the receiver is to be emptied, it can be removed from the strap almost instantly. Electric Bench Machine Has Many Uses AN ELECTRICALLY driven bench machine with a rotating toolholder adapted to work at any angle and to a great number of uses, recently has been developed. It consists of an _ electric motor and a horizontal carrier bar, to- gether with necessary fittings for carry- ing tools. The machine may be used for sawing, grinding, shaping, and tenoning. It also will carry lathe and jigsaw attachments, as well as a flexible shaft that permits its use for drilling of all kinds. A ‘‘Human Radio’’ Theory HE startling theory that every human being is a veritable wireless station, sending out waves of varying length that aid him in his daily work, is advanced by the famous inventor, Lakhovsky. He calls these waves ‘“‘human rays.” Lakhovsky believes that eventually it will be possible to eliminate maladies by overcoming radiations of microbes, and that some day men may converse at a distance by directing their own waves. Sprocketless Movie Machine to Save Film NEWLY designed sprocketless mo- tion-picture camera and _ projector device designed to do away with all sprockets and star wheels, thus eliminat- ing the perforating of films, has been perfected by George W. Bingham of 3rooklyn. He also is the inventor of the wideview and widescope motion-picture cameras. The chief advantage claimed for the new machine is that it will permit a film to run more than three years without showing material signs of wear. Present- day perforated film is good for only about three months. Another advantage is that the rollers are adjustable for shrinkage of film. Thumbscrews at the ends of two sets of rollers permit them to be expanded or contracted within a thousandth part of an inch. An oscillator literally whips the film into shape, though gently,-it is claimed, without tearing, doing the work that the star wheel does in the ordinary machine without jerking the pictures before the frame. It also is said to frame the pic- tures perfectly. Above is the sprocketless motion-picture projector, with its inventor, George W. Bingham. At the right are shown the adjustable rollers and oscil- lator that carry the film through the projector Signal Lights Save Diners NM INIATURE traffic towers are being aA used on after-dinner speakers’ tables in New York to curb the flow of oratory. Amber and green lights warn the speakers that their time is about to expire, while a red light is a signal for a full stop. In addition, the inventor claims his machine will per- mit the projecting of old and worn- out film that has been shelved be- cause the sprocket holes have become worn and torn

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1e ench older toa been 2ctrie *, to- arry- wing, t also 1ents, its its Ory uman ation, . that anced He lly it ies by , and } at 2a res, m about is that age of yf two anded 1 part e film aimed, at the achine re the le pic- tly. yn, the ims his ll per- jecting worn- at has od be- rocket yecome torn } : Core Drill “X-Rays” Concrete Road FEW years ago it was a difficult problem to determine the A thickness or cross-section composition of a concrete founda- - The general character of the concrete was learned by taking samples during construction, and whether these samples were representative or not depended on the inspector. The results of such tests often were of little value because inspectors sometimes worked with the idea that their services were judged py the perfect samples that they turned in. “This condition has been remedied by the invention of a machine that “X-rays” state highways or foundations. drill that extracts from the pavement a small core showing the quantity and quality of workmanship and material, from the tion or pavement. foundation to the upper surface. The test takes only 20 minutes and the small hole it leaves can be plugged up quickly. Two advantages of the drill that performs this operation are the use of inexpensive steel shot for the drilling instrument instead of the costly black diamonds used in other types of core drills, and the ability of the machine to eut cores of ample size. The cores are actual records of the finished road, and any kind of modern road material can be tested. The highway departments of Penn- sylvania, Illinois, Ohio, and other states now operate these drills as part of their regular equipment. Pneumatic Auto Springs Are Adjusted Easily IR-CUSHION springs to replace the 4% usual elliptical springs for auto- mobiles have been invented by James G. Hughes of Cincinnati, Ohio, who claims they offer greater resiliency, quicker action, and improved riding qualities. Three inflated pneumatic rubber tires of small dimension are joined by alu- minum rings or washers, which in turn are joined by a series of steel rods. Bolts and lugs for attaching to the car complete the apparatus. Iron rods extending from one end of the car frame to the other and connected directly between the pneumatic springs and the car frame prevent side slipping. _ Twenty pounds air pressure is suffi- cient for a large passenger car. For smaller cars only two sections of the cushion need be used and the air pressure can be regulated. The pneumatic spring and its inventor POPULAR SCIENCE MONTHLY It consists of a tag ee — The road-testing machine extracting a cross- section core of concrete, as shown at the left Novel Advertising Display Made of Glass Tubing NUSUAL display effects are said to be obtained by an inexpensive yet attractive advertising sign composed of a continuous length of glass tubing formed to any desired shape, through which brightly colored liquid continually dances. This is accomplished by connecting the inlet end of the tubing with a tank Map of England in colored tubing of colored water. From the tank small quantities of water drop into a glass tube container fitted with a side tube air vent. The liquid falling into the container draws air through the vent, breaking the stream of liquid into continually moving bubbles that work their way around the outlines of the sign. Telescope and Microscope in One Instrument MBODIED in this useful combina- tion optical instrument is a_ pris- matic telescope that can be converted quickly into an efficient microscope. All that is necessary to make the change is to attach a small tubular fitting that, like the telescope itself, can be carried in the vest pocket. The original telescope insures a three or sixfold magnification, while the micro- scope amplifies 42, 84, or 180 times. The same instrument may be used for examining small opaque objects, thus constituting what might be termed a tel- escopic magnifying lens.

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POPULAR SCIENCE MONTHLY vee ee x = CO- NVA GIO “WOW 8g i} 6 “4 3 1 0 — Nel - OHV SUMANIOOS i Calculating Machine Carried in Pocketbook AN INGENIOUS calculating machine that fits in the pocket and is operated merely by inserting a metal stylus in holes corresponding to figures and push- ing the holes to the ends of their columns, adds, subtracts, multiplies, and divides. The machine is carried in a leather case, and is the size of a pocketbook and may Simple Scraper Removes Mud from Shoes O KEEP mud tracks from the house and particularly from the parlor car- pet and so save the housewife unnecessary labor in stormy weather, the simple but effective shoe scraper shown above has been devised. It is equipped with a long handle to obviate the necessity of bending in removing mud from the shoes. The scraper is a double-edged metal knife attached to two metal prongs. The upper edge is used to scrape the soles of the shoes, while the lower edge is curved to fit the heels and uppers. RECENT tests by the Society of Automo- tive Engineers and the U. S. Bureau of Standards showed that autos skid less on clean, wet pavements than on dry ones. be used inside of a ledger if desired. The top of the stylus is an automatic pencil that may be used for tabulating calculations. The machine contains no wheels or springs and does not require oiling. Mistakes are recorded automatically. The result of calculations appears on both the addition and subtraction faces, so that debits can be added on one side and credits on the other. The final figure on the subtraction face shows balance due. Electric Screwdriver and Wrench Combined rw ELECTRIC = screwdriver and socket wrench, weighing but 15 pounds complete, has been perfected to speed production, cut costs and increase convenience on hundreds of jobs. It is designed particularly for driving very large wood screws and lagscrews and for running up nuts on large bolts. The spindle has a positive clutch that auto- matically disengages when forward pres- sure on the tool is released. The tool has a pistol grip and a trigger switch. Motors for voltages up to 250 are available. The light electric tool is shown be- low in use as a socket wrench, run- ning up a nut ona large bolt. At the left it is shown driving large screws Weighted Extension Lam)| Always Stands Upright ESIGNED especially for use in shor é or garages where light is required inf places remote from connections, a ney}. extension lamp not only will right itse} if overturned, but will pay out or reel i, 1 its own cord. A wire frame protecting 3 the bulb is surmounted by a hook by which the lamp can be hung. i The weight of a ball base, which con 1 tains many yards of cord, causes th ™ light to right itself. The length of cor desired is obtained simply by connecting with a socket and then carrying the light 4 The complete extension lamp equipment where it is needed, the cord paying out : from a weighted spindle within the ball. | When finished with the light, the user 7 disconnects it from the socket and rotates the wire guard, which draws in the cord, the weight, which is also rotating, aiding the operation. STEAM from locomotive boilers is being used by the Southern Railway to kill weeds along the right of way. Passing through perforated pipes the steam hits the weeds at a high pressure. fo th in ah or Tu

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es o show J red in f= a new yy - itsel FF reel in -ecting Fi ok by h con i es th # of cord necting | e light @ — E RAEI EY pment ying out & the ball. § the user d rotates § the cord, g, aiding is being y to kill Passing ‘eam hits Novel Pistol-Watch Fires Bullets through Stem AS A protection against thugs, a £% French inventor recently designed a watch which, to all outward appearance, looks innocent enough, but which in reality is a small pistol, capable of kill- ing at close range. The stem of Give: weastieh serves as the barrel of the gun, which con- tains four bul- lets of small caliber. The bullets are fired by pressing a small trigger on the edge of the watchcase. An ordinary watch guard is attached to the ‘‘timepiece”’ as a disguise. Ready to shoot Alcohol as a_ Pipe-Cleaner HE usually disagreeable task of clean- ing a tobacco pipe that has been used for a long time is said to be accomplished thoroughly and quickly, simply by apply- ing a match to the little device shown above. It consists of a glass tube with a bulb at one end, attached to the pipe stem by a rubber tube. The bulb end is filled with alcohol and heated for a few seconds over the flame of amatch. The heat causes the alcohol to flow through the stem, loosening the sediment and car- rying it back into the bulb. shown fully extended at the right POPULAR SCIENCE MONTHLY Huge Armature ITHIN this gigantic armature, a whole company of Swedish soldiers, 172 men, is seen assembled, with plenty of room to spare. The 11,000-volt dynamo of which it is Holds Company of Soldiers a part will feed power to the Swedish State Railway. It is one of a number of huge dynamos being built for the Swedish General Electric Company, now tapping Sweden’s enormous water resources. London Fire Department Has 85-Foot Ladder N 85-FOOT extension ladder that serves either as a fire-escape or a water-tower, is the last word in equip- ment of the London, England, fire de- partment. It is carried on a 65-horse- power motor-truck chassis. The hydraulic pressure for raising, ex- tending, and revolving the ladder on its turntable is provided by a three-throw pump at the rear of the truck, driven from the engine shaft. The ladder can be extended to its full height, it is said, in less than a minute. SSGRURERERD-- “SORE SOG 0004 DOERS DEES LT] Ym is “fg Airplane Hand Crank Aids Fliers in Starting Ee: two men are required to start an airplane engine, one at the starting switch and one turning the propeller. Aviators forced down in unin- habited districts find it difficult and sometimes impossible to start their en- gines if they are operating the plane alone. For this reason, many planes of the latest design are equipped with cranks, resembling automobile cranks. These permit the aviator to turn over the engine while operating the switch. Radio Velocity Measured |? ipa a motion-picture device, ex- perts of the Radio Corporation of America recently succeeded in measuring the velocity of radio impulses. A radio signal was recorded as making a circuit of 8500 miles between the corporation’s sending station at New Brunswick, N. J., and Warsaw, Poland, in .054 second. A 14-tube receiving set was used.

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POPULAR SCIENCE MONTHLY | 4 ee PIDERS usually are considered little more than a nuisance, but to George Hannes of Toledo, Ohio, pictured above, they have been the backbone of an unusual business for the past 35 years. _ The World’s Largest Shell N ONSTERS of the past and present are being mounted and cast in re- productions of their original form in a special department of the British Na- tural History Museum at London. Huge models of prehistoric creatures often are made up from a few bones. One of these is a restoration of the world’s largest shell, shown above. It is a gigantic fresh-water shell standing higher than a man. The actual spe- cimens on which the model is based were found in rock strata. Two of the original fragments are shown. One of them is held by F. O. Barlow, who constructed the model. His Business Is Collecting Spider Webs Hannes is a spider expert who collects spider webs for use in surveying instru- ments. The fine strands are the strongest and the thinnest obtainable. Since they are only about five ten-thousandths of an inch thick, they are said to serve better than any other substance for the cross hairs on the surveyor’s telescopes or for field glasses. The web is taken from the insects by allowing them to drop from a loom. As fast as they drop, the web, left behind, is wound on spools and placed in storage. A certain species known as the Michigan gray and brown spotted spider is raised for the purpose. This Man-Made “Caw” LACK days are ahead for crows. Hereafter not even the friendliest “caw” can be trusted. It may be a man-made lure calling them within gun- shot. For a crow call said to imitate their cries perfectly has been invented for The Hard-Working Elephant Enjoys His Bath AN ELEPHANT driver at Kandy, Ceylon, is shown below, giving his charge a thorough washing after a hard day’s work. Although it is not generally known, the elephant is one of the cleanest of ani- mals and one of his greatest delights is playing about in water. This one seems to be enjoying his bath thoroughly. IN THE Siskiyou Mountains of California, forest rangers report the discovery of a tribe of Indians who communicate only by whistling and who can talk to birds. Lures Crows to Death Crows find little sympathy from the farmer. Not only do they destroy farm crops and raid poultry yards, but they are a menace to useful birds, whose nests they rob. the use of farmers whose crops suffer from the black marauders. Experts say that there are numer- ous variations of the “caw,’’ such as a warning note and a call to feed. Therefore, the new lure is made so that the reed of the instrument may be taken apart and adjusted to give coarser or finer tones. A few hours spent listening to crows and watching the actions that ac- company and follow their cries, it is claimed, will enable a hunter to understand and to answer them. A farmer-hunter sounding the crow call with the ingenious reed instrument shown at the left. The instrument can be taken apart and adjusted to re- produce variations of the crow’s “‘caw re B 2( fo Wi be of ph

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ant andy, ig his hard nown, f ani- lights ; bath = lifornia, ry of a ite only birds. eath “om the oy farm they are se nests row call trument 1ent can to .Te- 2 steel mill of the Ford plant. Writes, Prints, and Binds Books Single Handed NE of the most unusual “one-man O jobs” in history was completed recently when Dard Hunter turned out 900 copies of a book on which he per- formed every task himself, from the writing of it to the finished volume. The book—a history of papermaking— is the outgrowth of several years of research on the part of the author-maker. APEEE RD EY The writer-bookmaker at his press With his manuscript completed he made enough paper for 200 volumes, then cut, cast, and set his type, printed the edition himself, and finished his task by doing all the binding. The volumes are said to be examples of fine workmanship. POPULAR SCIENCE MONTHLY | VEN the farm animals are learning to keep step with the progress of science. In Wall Lake, Ia., a lad by the name of Robert Ralph owns a hungry calf whose feeding took too much of its youthful owner’s time. So he perfected an auto- matic feeding machine with an alarm clock attached. At feeding time the alarm rings and the calf comes scampering across the barnyard to his meal. The clapper on the bell releases a ball that opens a shoot and lets the grain from a hopper drop to a feeding trough below. All Ralph has to do is fill the hopper Midget and Monster in Armature Building A STRIKING example of the most recent progress in the construction of electrical machinery is offered in the photograph below, which shows a giant armature weighing 96,000 pounds and a second one, equally complete, weighing 614 ounces, Both armatures were assembled in the same building of the Schenectady Works of the Generai Electric Company. The huge piece of apparatus is for a motor that is being constructed for use in The motor of which it will be a part will develop 4500 horsepower, and the armature will revolve 67 times a minute. The tiny armature winding that is shown in the hand of Miss Edith Bartlett was rewound by the service department for use in a small blower The young woman in the Picture is hold- ing the mid- eet armature that was to be used in the General Electric Company hospital. The diameter of the large armature winding is 13 1/3 feet, while that of the midget is only 114 inches. Young Inventor Feeds Calf ie Clockiwoslt with grain, set the clock for feeding time, and let the calf do the rest. inventor is shown above with his in- genious homemade machine. The young a ed i ‘oy: Giant Radio Insulator HE largest radio insulator in the world is used by the navy at high- power stations and is known as the Navy Type, SE-1560. It consists of two parallel porcelain rods six feet long, secured by yokes with shields attached to the an- tenna end. The over-all length of the complete insulator, including yokes, is eight feet 534 inches. The working load is ap- proximately three tons. Under test these units, flashed over, when wet, at about 460,000 volts at 60 cycles.

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POPULAR SCIENCE MONTHLY * i (a ® se Seo OAS Sih cites Ee we N FORMER days of cattle epidemics, the four-footed creatures were the only ones subjected to rigorous disinfecting baths, but science today recognizes no dividing lines and includes the automo- bile in the list. “Sheep Dip” for Autos to Comb As a preventive against the further spread of hoof-and-mouth disease, which is threatening the live-stock industries of the state of California, where a statewide quarantine was declared, disinfecting troughs for cars have been placed at many at Hoof-and-Mouth Epidemic county lines, and a!l cars must use them In order to check the carrying of germ by man over broad areas in the state every automobile must pass_ throug shallow vats filled with strong disinfectiy fluids before passing into the next county, Kerosene Spray Designed to Clean Auto Engine KEROSENE vapor spray device for cleaning grease, oil, and dust from automobile engines and other machinery recently has been developed. It consists of a nozzle with a double jet, one of which is attached to the compressed-air line and the other to a kerosene can. As the air is released from the airline, passing through the hose and out of the jet, it sucks up kerosene through the hose connected with the can. The cleaner is operated on the injector principle and a powerful spray of kerosene and air is thrown against the motor, quickly clean- ing off dirt and grease. The flow of kerosene can be regulated at will. After the engine surface is cleaned, the kerosene is shut off and the motor is dried with the air. Lightweight Car Designed without Chassis ff usual N THE production of a remarkable automobile without the usual chassis, a French engineer claims to have achieved an improvement that may have a revolu- tionary effect on automotive design. Instead of the usual frame, a single beam connects the front and rear axles. The engine, instead of being under the Bicycle Lock Holder ICYCLES are safeguarded more con- veniently against theft, it is claimed, with a new lock holder that is attached permanently to one of the rear frame supports and will work with any padlock of the proper size that has a hasp long enough to reach the opposite frame sup- port. The sheath in which the lock rests hinges back when the wheel is locked, covering the heads of the screws that attach the holder to the frame. When thus hinged back, the sheath is closed at the bottom by a clip with two holes through which the two rods of the hasp are run. a“ ARTICLE on the thyroid gland, announced for this month, will be published in a forthcoming issue, owing to the fact that tmportant additional material is in process of preparation by the author. One beam connect- ing front and rear axles replaces the chassis, shown below. Note position of the en- gine at the rear as Attached Permanently © K.& H. hood in front, is mounted in the rear. Advantages claimed for this type of construction are that less material is re quired in construction, tire wear is les sened as the result of the decrease in weight, and transmission is improved. In addition, the narrower body offers les wind resistance. The new padlock holder is at- tached permanently to a rear frame support as shown above ome tri eq ca oT ——

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se them, of germ: 1e State throug infecting county, ISSiS the rear. type of rial is re ar is le crease il coved. In ffers less ently POPULAR SCIENCE MONTHLY See ee SE a en ee (SAE Fee a ) gertaalecoeiag especially for road con- struction work, a new two-way drive truck runs backward or forward with equal facility. In other words, it always can reach its objective in the most direct Motor Truck with Twi Way way without the necessity of turning around. Thus the necessity for filling ditches and removing forms for turning purposes is obviated. In addition, the short wheel-base—128 Drive Designed for Road Work inches—and specially arranged steering mechanism make it possible to turn the truck in an unusually short circle. The machine is shown above dumping its load into a concrete mixer. Testing Device Simplifies Motor Timing 4 PLUNGER KNOB PISTON O The plunger knob of the new tester rises and falls with the cyl- inder com- pression O CLEARLY is the position of the piston in the cylinder indicated by a recently invented timing tester, that the user can time the spark and valves, be- sides determining quickly the correct fir- ing order, enabling him to assemble the ignition wires properly—all without dis- mantling the engine. The device consists of a _ balanced plunger surmounted by an indicator ball. These rise and fall with the compression in the cylinder. The upper part is used as a spark-plug terminal. Besides the usual binder nut, it has a new spring fastener that enables one to attach the ignition wire instantly. The tester also determines precisely when the cylinder is ready to burn out carbon, for it indicates when the piston is at top dead center, with both valves closed. Portable Trouble Lamp Useful to Campers froR night repairs on the road or lighting an auto-camper’s tent, this new port- able electric trouble light is especially adapted. A heavy spring clip with rubber grips fastens the light at almost any part of the car. The frame can be swung in a complete circle, bent up or down, or set at any angle, throwing the rays exactly where they are needed. A 10-foot cord plugs into any light socket on the car. carrying the light MX The trouble light with spring clips by which it is attached Auto Engine Used to Run Garage Elevator HE Ford engine has been made to serve many purposes, but none more unusual than that to which an inventive garage owner has put it. He makes it drive an elevator that transfers auto- mobiles from the first to the second floor of the garage. The engine was mounted on a wooden framework and attached to the support- ing beams of the elevator mechanism as shown above. A Ford rear axle shaft was squared at one end, fitted in the universal joint socket of the engine, and supported at the rear by a cross bar holding a rear axle roller bearing. On the projecting end of the shaft was keyed a_ two-foot separator pulley. V-shaped wooden blocks were fitted in the rope groove of the five-foot elevator pul- ley, and an old belt running between the pulleys completed the unique and in- genious outfit.

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POPULAR SCIENCE MONTHLY Crossing the finish tape, the runners are automatically photographed and timed ‘by the three-dial clock shown at the right Electric Clock Times and Photographs Runners HUGE electric clock with dials, said to record time to one thousandth of a second, has been in- vented for important athletic contests such as the Olympic Games this summer. It can be connected with a camera so that a picture of the finish of a race is photo- graphed, indisputably establishing the order of the runners, should a difference of opinion arise. The clock is started by the firing of the starting pistol. Its hands are stopped the instant the runner breaks the finish tape. The clock and its hands are so large that the time can be read by many of the spec- tators; yet by means of its three dials it is graduated down to record fractions of a second. three B LASS so tough that when blown into a hollow sphere it can be kicked about like a football has been invented by Doctor Horak, a Czech engineer. While he does not claim to have found the secret of unbreakable glass, he declares his glass is tougher than any heretofore known. can you tell why this is so? Then try them on your friends. month. 8. Can plants see? How Much Science Do You Know? CIENCE is an indispensable part of our daily lives. scientific reason for nearly everything we use. How much do you know about the ‘“‘why”’ of these things? For instance, every one knows that a soap bubble is always round, but Knowing the explanation of some of the hundreds of similar questions that come up daily will give you a liberal insight into science. will be found a dozen questions picked at random on various subjects. How many of them can you answer correctly> After you have written down the answers to the best of your ability turn back to page 119 and see how nearly you are right: but don’t read the correct answers until you have considered each question thoroughly. There will be 12 more questions next 1. Why is a man usually stronger than a woman? 2. How could you start a fire if you had no matches? 3. How large is the earth in thickness and circumference? 4. Why are there no fish in the Dead Sea? 5. What are icebergs and how are they formed? 6. Why does a wood fire snap and crackle? 7. What is the largest living animal on earth? 9. What was the first metal to be used by man? 10. Where did the American Indians come from? 11. How does a towel dry your hands? 12. Why is the formation of a soap bubble always round? There is a do and every article we Below Metal Bucket for Berry Picking, Saves Fruit ERRIES and other soft fruits can be picked more conveniently and with less loss from bruises, it is claimed, with a new bucket de- signed to hang from a band across the picker’s shoulders. The metal container, open at the top and bottom, incloses a canvas bag that also can be opened at both ends. While the bucket is being filled, a ring attached to the edge of the bottom mouth of the bag is engaged by a snap near the top of the metal body on the front. the bag. This closes When the bucket is set on the ground, it rests on supports that keep the bottom of the bag from touching the ground, and thus prevent bruising of the fruit. The metal body also protects the fruit from side blows or pressure. The snap and ring are disengaged when the bucket is to be emptied, opening the bag and allowing the fruit to be deposited gently in a receptacle. The bucket has a concave back con- forming to the picker’s body. a —— The new bucket with canvas bottom open Ocean Flight of ZR-3 to Mark Aerial Progress ITHIN a few weeks the great dirigible ZR-3, built by the Zep- pelin Company for the United States Government, is expected to fly from Friedrichshafen, Germany, for America. No more thrilling illustration of the prog- ress of modern science probably could be furnished than this of an airship under- taking a perilous voyage across the Atlantic quite as readily as would an ocean liner. The ZR-3 is the first passenger-carrying airship, designed for other than military purposes, to be built for use in this coun- try. In design and construction she 1s said to be the most beautiful and luxuri- ous airship ever built. She is 656 feet long and 90.7 feet in diameter—not 989 feet in length and 130 feet in diameter, as erroneously stated in a recent issue of this magazine. Her total volume is 2,400,000 cubic feet. Her five engines of 400 horsepower each are capable of driving her at a speed of 75 miles an hour. wat clait allo in t rem esca Jt plug inse} is a slee’ vent Ti nece the 1 wate Afte sligh from trou! Aut comp ten fr this f. trated Eve: son, b ductio ithe yp IScienc | The Nordr of Pa: Wonde langua The James the ne Which Meet, Tech Specifi Manus ond Ei

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ked rom de- the and 1 be eing tom the oses und, ‘tom and The from when r the sited con- open to S great 2 Zep- States from nerica. > prog- yuld be under- ss the uld an arrying nilitary s coun- she is juxuri- 56 feet not 985 eter, as > of this 400,000 sepower a speed New Safety Plug Drains Water from Gas Pipes HE dangerous stream of escaping gas that often accompanies removal of water from gas pipes is avoided, it is claimed, by a new draining plug which allows the water that has accumulated in the water trap to be drained without removing the plug or allowing any gas to escape. The new cap is similar to the usual plug with the addition of a small nipple inserted in the bottom. In the end of this is a small lateral opening and a revolving sleeve with cap that opens or closes the vent. To drain the water from the trap it is necessary merely to turn the collar to open the vent. The gas pressure forces out the water through the vent in a small stream. After the water has completely run out, a slight twist of the collar prevents any gas from escaping and does away with the trouble of removing the entire plug. Draining the water through the vent Recent Publications A résumé of new books on science and invention Autocamping, by F. E. Brimmer. A comprehensive, practical handbook writ- ten from the experiences of a pioneer in this fascinating outdoor pastime. Illus- trated. D. Appleton & Company. Everyday Biology, by J. Arthur Thom- son. A popular and unconventional intro- duction to the study of living things by the noted editor of ‘“‘The Outline of | Science.” George H. Doran Company. The Kingdom of the Stars, by Charles Nordmann, astronomer of the University of Paris. The enthralling story of the Wonder of the heavens told in popular ‘anguage. D. Appleton & Company. The Hun anizing of Knowledge, by James Harvey Robinson. A discussion of ee hecessity for a common ground on "hich science and the ordinary man may meet. George H. Doran Company. _ echnical Writing, by T. A. Rickard. *pecific instructions on the preparation of “anuscripts on scientifie subjects. Sec- ond Edition. John Wiley & Sons. POPULAR SCIENCE MONTHLY Drops Eight Stories in Vest Pocket Fire Escape HE proof of the pudding is in the eating and the success of a fire escape lies in its utility. To prove his faith in his invention of a ‘‘vest pocket fire escape,” Peter P. Vescovi crawled out of an eighth- story window of a New York hotel recently, attached his device to the small railing just outside the window and safely descended to the ground. The “‘fire escape’’ consists of a compact roll of 75 feet of steel tape tested to hold The inventor attaching his pocket fire-escape preparatory to his descent from the eighth story (at the left) 750 pounds. It is unwound from a little wheel inside the case, the speed of release being regulated by a brake. A strap fastened around the body attaches the “fire escape’’ to the user. Vescovi bravely demonstrated his device before half a dozen police and fire officials while a large crowd in the street watched his breath-taking descent. Birds Still Champions OR untold ages before the American round-the-world fliers started on their adventurous trip, certain birds called “arctic terns’ have been making a trip of 22,000 miles each year from their breeding grounds in the north polar regions to feeding grounds in the antarc- tic, and back again. Man still has some distance to go to match the birds’ records. SN | Know Your Car HE occasional jamming or locking of a starting motor is a problem that usually baffles the auto driver who fails to understand that it is chiefly his own fault. If the priming rod is not pulled out long enough in pressing the starting button or foot switch, not enough gas is drawn into the cylinders to fire all of them. The result is that if the engine is cool, the motor turns a revolution or so and when the unfired cylinder is on the compression stroke, the piston compresses the charge and rebounds, turning in the opposite direction. When the foot presses the switch at this time, while the flywheel is turning in the reverse direction, the pinion is thrown into engagement and the two oppositely turning gears— the starter gear and the flywheel gear —are engaged. Since one cannot overcome the inertia of the other, the When the Starting Motor Jams _ effort to increase the movement of result is that the compensating spring is locked tight with the gears in mesh. To avoid this, the operator should not press the switch until the motor has time to come entirely to rest. The best way to free a locked gear is as follows: Engage the high-speed gear with the clutch in and the igni- tion switch thrown off. Now grasp the spokes of one of the wheels, and turning this wheel as if to move the car forward, take out all the lost mo- tion. Then quickly turn in the op- posite direction as if to back the car. Try this several times, mdking an the car each time by applying more effort. Usually the motor can be dis- engaged by this method and the labor of removing the starter can be avoided.

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62 Adventures in Home Ownership We Plan Household Equipment, Specifications, and Contracts HIS 1s the fourth article in Mr. Riley’s interesting series describing the home-buying adventures of Jim and Marion Hunter. In preceding articles, Mr. Riley told of their house-hunting expeditions, of their purchase of an in- expensive ready-built home to live in until Jim’s expected salary increase should materialize, and finally of their selection of the building plans for a permanent home. In the following article, the story of the Hunters is concluded. When you have read it, you won't want to miss an equally readable series on how to save money in building a house, beginning next month. ad a | PY oe eee ee The house that “\ULLY two weeks had elapsed since I had heard from Jim and Marion Hunter about their proposed new home. It was no surprise to me, therefore, as [sat on my screened porch reading the paper one Sunday morning recently, to be hailed cheerily from an approaching motor car and presently to see Jim and Marion hurrying toward me across the lawn. “We've bought the land!’’ announced Marion breathlessly, sinking into the couch hammock at my side. ‘Half an acre of it.” **As usual, it’s a compromise,”’ laughed Jim. *‘Marion wanted to be in a thickly settled suburb; I in the country. We’ve located just where the two seem to meet, and land enough for lawns, flowers, and a garden is not too expensive. The altera- tions in the plans are complete, specifica- tions are being drawn, and we expect to be ready to start building soon.” “And we thought that perhaps you’d have a few suggestions to offer about let- Jim and Marion built, arrangement and equipment of the rooms on one side. Note how the cellar is divided by partitions into several rooms, this view showing the laundry with its electrical equipment, the heater room, and vege- table cellar. The kitchen in the rear of the first floor has a large white POPULAR SCIENCE MONTHLY By Phil M. Riley Noted American Authority on Architecture and Building , ting the building contracts,’’ Marion chimed in. ‘Possibly, too, you can give us some ideas on equipment that might help in rounding out completely the specifications for our new home.”’ broken away to show “You bet I can,’’ I assured them, add- ing the suggestion that, if they cared to look, I might show them some of the things that had given me pleasure in my own home. And so we strolled out into the vard, where we began with a discussion of outdoor specifications. “Your house, like mine,’ I said, “‘is going to be shingled. Use cypress. It’s the most lasting of woods. Dip the shingles in shingle stain before laying and never paint them. Paint on a shingle surface encourages dry rot under it. You an get a cream or the good old plantation white in a creosote stain that sinks into and preserves the wood, and it can be used on both the shingles and trim. _. me urge you also to have a slate roof,’ I went on. “It costs more at the start, but it’s permanent, fireproof, and of excellent appearance—a good in- vestment. The same is true of copper conductor pipes, flashings and valleys enamel sink and drain table, also white enamel electric dishwasher. All rooms are plentifully supplied with plug sockets for lamps, vacuum cleaner, and other electrical household devices. connected with plug socket in the front bedroom. Ample storage space is provided in the roomy attic, which also contains maid’s room and bath on the roof and screen wire. In building a permanent home, it pays in the long run to buy the most enduring materials Don’t think of using ordinary building bricks for your chimney and fireplace The various tapestry types have a de lightful texture and variety of color that are well worth the slightly additional price.”’ As we passed around to the back of the house, Marion’s eye caught the underground garbage receiver near the back door. Notice the electric fan “Thatisa good thing, isn’t it?” she asked. “Where garbage collections are depend- able, it’s the best arrangement,” I an- swered; “‘otherwise an incinerator is de- sirable. See, it opens with the foot like this, and the pail comes out for emptying. Dogs, cats and flies have no chance to get at the garbage and a clean service yard is assured.” a HAT’S that?” asked Jim, pointing to a metallic door in the basement wall near the garage driveway. “That’s my coal chute. See, the heavy steel hopper drops down and catches all the coal, while the door opens and fastens upward, protecting the building where it’s most needed—no blackened and battered sash and window frames.”’ ‘How about locking it?” “Upon closing the hopper, it locks automatically on the inside, and is double locked by a special key on the outside. When not in use, the hopper lies in the “bh spi tit yo loc spi tal liv

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p } Lilding € long terials, uilding eplace a de or that litional ack of it the ar the er. im fan ace ath she asked. e depend- ” i - ‘or is de- foot like mptying. nee to get ce yard is , pointing basement the heavy atches all nd fastens ng where oned and ” es. it locks 1 is double lies in the chute body, out of everybody’s way.” From the yard we entered the cellar. “How do you keep it so clean?”’ was Marion’s first comment as we descended the stairs. Piemeel foundation walls and floors are a great help,’”’ I told her; “but the real secret lies in dividing the space into several rooms by wood par- titions. Here at one end of the house, you see, is the heater room in which is located the heating plant, coal bins, space for ash barrels and a full height basement door where the ash barrels are taken out. Here also the pit under the living-room fireplace is emptied. This POPULAR SCIENCE MONTHLY ““Yes,”’ I answered, leading the way. “This, you see, is another separate room of ample size for the set tubs, an electric washing machine, and a mangle.” Next I called their attention to two elec- tric plug sockets for the laundry machin- ery, and a gas connection for the mangle. “You'll want plenty of these plug sockets throughout the house,” I re- minded them. ‘‘There should be at least one and preferably two in the wall, base- board, or floor of every room. Remember this is an electric age and provision must be made for floor and table lamps, fans, portable heaters, vacuum cleaners, piano players, irons, toasters, coffee percolators, chafing dishes, waffle irons and grills, also various bed- room and bath- room devices.” “T suppose,” hazarded Ma- rion, “it would be a gdod plan to furnish each room of our house on pa- per, so to speak, and plan the electric wiring accordingly be- fore the house is built.” “That’s the point exactly, and a good way tosavemoney,” I agreed. The neat laundry in the basement, showing electrical washing machine and mangle, set tubs, built-in closet for ironing-board and iron, and mul- The floor is of waterproof rubber tile tiple clothes-rack at the left. keeps all ashes and coal dust away from the rest of the cellar.’ I pointed out how the hot-water fur- nace and all the pipes were covered with ashestos, explaining that although this provision costs little, it insures the heat’s going to the rooms above instead of being wasted in the cellar. I described, too, the automatic heat-regulating system. “RHE regulating dial is in the living- room above. You simply set the dial for the temperature you want, keep the fire properly tended as to coal supply and removal of ashes, and the regulator keeps the drafts set to maintain the de- sired temperature day and night.” “Isn’t it wonderful!’”’ cried Marion. “Yes, and there is another interesting thing about my heating plant,” I con- tinued. “Behind every radiator in the house hangs a special container kept full of water that gradually: evaporates and maintains normal humidity of the air. This makes for better health, fewer colds, less throat trouble and helps to preserve woodwork and furniture from overdrying with consequent shrinkage and pulling apart.” From the furnace I led them to a door opening into the vegetable cellar, under the sun porch where a garage often is located. I explained how this cellar is xept cold by a concrete partition separat- ne ‘t from the rest of the cellar, and ‘towed them the shelves along the sides, for preserves and canned goods. Your laundry is in the basement, too?” queried Marion. Upstairs, Marion was de- lighted with the kitchen ar- rangements, es- pecially the flooring and baseboard of rubber tile with three-tone grain effects like marble. She was impressed, too, with its sanitary, noiseless, non-slippery, waterproof, and durable qualities. Other features that caught her eye were the large white enamel sink with combined draining table, and the white enamel electric dishwasher that when closed served as a kitchen table. “Now I want you to look at my win- dows,” I said, as we entered the dining- room. “All are hung on metal chains that never rot and break nor come un- fastened like cotton cord. These are pivot windows, you see. Each sash slides up and down, yet it also can be swung in- ward for cleaning both sides. Notice also how smoothly they slide and how tightly they fit in those — — Courtesy Home Owners’ Service 63 “What a delightful great fireplace!” cried Marion enthusiastically. “Yes, it is,” I agreed with some pride. “And that reminds me of a caution I want to give you. A fireplace that smokes is an abomination. Two precautions will prevent it. Make sure that yours has at the back of its throat a smoke shelf of ample width to deflect the down and start the up draft, and that the cross sectional area of the flue lining is not less than one- ° twelfth the area of the fireplace opening. You'll need a flue damper. Notice how easily this one is controlled outside by this unobtrusive little brass knob.” OING up to the second floor, I again called attention to the plug sockets in the halls for table-lamp and vacuum- cleaner use, and I pointed out the econ- omy of having most of the plumbing centralized practically in a vertical line at the back of the house, the laundry below the kitchen, the hall and master’s private baths above, and the maid’s bath on the third floor over the hall bath. “Your bathrooms are just my idea— all white fixtures,” said Marion. “The best is really the cheapest and most satisfactory in plumbing fixtures,” I said. “Tile floors and wainscots are easily kept clean and prevent damage due to splashed water. Rubber is equally good. Tubs fitting exactly into one end of the room with solid bases down to the floor prevent accumulation of unsightly and unsanitary dust under them, while lava- tories supported on a standard make cleaning around them easy.” " HAT surely appeals to the house- wife,”’ agreed Marion. ‘Notice now that the bathroom door swings into the bedroom,” I pointed out. “See, on the back is a full-length mirror, a substitute for a pier glass without taking up so much room. Now look at this white enameled steel medicine cabinet set into the wall with its mirror door. (Continued on page 116) metal weather strips. That means winter comfort and a saving of several tons of coal a year.” “Your front door also is well protected, I noticed,” commented Jim as we passed to the living-room. ‘‘Yes, it has wood weather strips all around it, and that glazed vesti- bule on the front porch keeps much of the cold out in winter. It’s a great comfort when somebody comes to the door for a few minutes, and it really adds distinction to the appearance of the house.” Courtesy Home Owners’ Service Above is the white bathroom, showing tile floors and wains- cots, porcelain tub and lava- tory. white enameled steel medicine cabinet and mirror set in the wall. and built-in toilet receptacles. At left is the breakfast nook off the kitchen

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64 Two Radio Receivers in One How to Build a Combination One- and Three-Tube Portable Set By Joseph Calcaterra Radio Editor of POPULAR SCIENCE MONTHLY A recent radio show I overheard a visitor commenting on a so-called A ‘“‘portable”’ set. POPULAR SCIENCE MONTHLY good pair of phones attached to a horn. Local stations came in loud and clear. The symbols on the wiring diagram on this page have been numbered to cor- respond to the numbers assigned the parts in the photograph of the panel layout. variable grid leak and fixed condenser. 4 fixed condenser and fixed leak may he used instead. Numbers 9, 18, and 19 are the detector, first stage and second stage tube sockets, Numbers 10 and 28 are the rheostats, Those giving a fine adjustment “That set is portable,’ he said, “if you happen to have three husky fellows handy.” This remark I kept in mind in designing the portable set I shall describe this month—a really portable set, yet one that will give just as good service in the home as it will on a trip. An unusual feature is the construction of the set in two units. The first is a detector unit; the second a two-stage amplifier unit. These units are to be preferred. Number 11 is a mica fixed condenser. Its value may vary from .0001 to .001 microfarad, Number 12 is the positive 4 and negative B battery post. Number 13 is the negative A battery post and No. 14 is the positive B battery post for the detector stage. Numbers 15, 22, and 23 are jacks. Terminals A and D are the outside springs. B connects with the _ inside were made for each other, so that the detector unit can be Front view of the panel, showing controls of the detector unit (at left) and the detachable amplifier unit (at right) used either alone or in connection with the two-stage amplifier. The weight of the detector unit alone is 3'¢ pounds and that of the amplifier unit is 214 pounds, making a total weight, when both are used together as a single unit, of 534 pounds. INCE the set is designed for use with the UV-199 and C-299 types of tubes, a 414-volt C battery can be used as the A battery and a small 45-volt battery as the B battery. The C battery is a minia- ture 414-volt flashlight battery. With complete accessories including phones, aerial equipment, batteries and carrying case, the total weight of the outfit will not exceed 13 pounds, if care is taken to select lightweight parts. In designing the circuit, I have modified a standard regenerative circuit along lines similar to those in the one-tube set described in the January issue, with which readers of POPULAR SCIENCE MONTHLY have reported exceptional results. Using only the detector stage of the portable set, Chicago stations (700 miles away) have come in loud enough to be heard clearly throughout my laboratory. he loudspeaker I used consisted of a Rear view, showing parts lettered and numbered to correspond with wiring diragram Numbers 1 and 2 are the aerial and spring that makes contact with outside spring A, while ter- minal C connects with the inside spring that makes contact with out- side spring D. The last jack may be a single-circuit jack, but the other two’should be double- circuit ones. Numbers 16 and 17 are the connecting wires from the primary of transformer 24. These wires are connected with the B and C terminals, respectively, of jack 15 when the amplifier unit is to be used with the detector. UMBER 20 is the negative A battery, and number 21 is the positive A battery connection. These posts are con- nected with numbers 13 and 12, respec- tively, of the detector stage when the amplifier unit is added to the detector. Number 24 is the first stage trans- former and No. 25 the second stage trans- former. Small-size audio-fre- a quency transformers should be ground posts re- spectively. Num- bers 3 and 4 are the aerial and ground switches respectively. Switch No. 3 has seven switchpoints \3 and two switchstops, while switch No. 4 is provided with six switchpoints and two switchstops. Number 5 is the stator wind- ing and No. 6 the rotor winding of a standard or homemade variocoupler. The one used in this instance was homemade, having 60 turns of No. 24 d.s.c. wire tapped at every 10 turns for the stator winding and 40 turns of No. 22 d.s.c. wire for the rotor winding. The stator winding was wound on a four-inch tube and the rotor winding on a 3!4-inch rotor. Number 7 is a .0005 microfarad (from 23- to 25-plate) Vernier variable con- denser. The rotary plates terminal is marked A and the stationary plates ter- minal is marked B. Number 8 is a well-known type of isisonnacee 3 The complete wiring diagram B BATT | -T5 used to conserve space and to keep the weight of the set down to a minimum. Number 26 is the 414-volt flashlight battery that is used as the C battery. Number 27 is the positive B battery post of the amplifier stages. , The panel used for the detector stage 1s 10 inches long by seven inches wide. That used for the amplifier is four inches long by seven inches wide. The detector unit baseboard is nine inches long by 4'2 inches wide, leaving a space of one half inch from each edge of the panel. ee The baseboard for the amplifier unit 1s (Continued on page 117) Terminal 3 pupayinr See: X por —s vo edt ct ct HM CO Cg 4 ~_——- Pe ~~ Df TTD OFTtlUCUCMO!UCC > ios an a a ae ee a ae

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1e Set nser. A may be letector, sockets, leostats, ustment ca fixed lay vary rofarad, sitive A ry post. rative A 14 is the t for the d 23 are 1d D are "erminal e inside act with hile ter- rith the vith out- le-circuit > double. nnecting rmer 24. ne B and jack 15 sed with battery, sitive A are con- , Tespec- hen the ector. e trans- ge trans- udio-fre- ould be 19 °

mplete iagram <eep the num. lashlight battery. ery post - stage is le. That hes long stor unit by 4!2 one half rr unit is

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POPULAR SCIENCE MONTHLY

Experts say that the next great step in the progress of radio will be the success of broadcast radio vision. Here is one of the recent inventions for the reception of photographs by wireless. At the extreme left of the picture is the receiver that picks up radio waves on which have been impinged light waves. At the center is a radio

y; é, i 4 tting E-BROADCASTING undoubtedly R is the year’s most important de- velopment in radio. Re-broad- casting is exactly what its name implies— a second broadcasting by several sta- tions of radio programs transmitted to them from the stations at which the programs take place, thus multiplying greatly the distance through which the programs travel and increasing the num- ber of potential listeners. Of course, in the case of presidential addresses and other important events, this has been done many times by means of land telephone lines. But through the recent development of an extraordinary short-wave transmission system, the entire process now can be accomplished by radio, and the frequently discussed possibility of one man’s addressing the = world probably soon will be real- ized. THE principle upon which radio re- broadcasting depends is quite simple, although the technical difficulties sur- mounted in its development were tre- mendous. In re-broadcasting, a program ls transmitted on two wave lengths. One isin the broadcasting range of from 250 . to 600 meters. These signals can be picked up by ordinary receivers within Tange. The other is 100 meters or less, which is below the receiving range of ordinary receivers. The re-broadcasting stations, however, are equipped with receivers capable of picking up the short-wave signals, and, when they are received, they are re- broadcast automatically over a wave length within the broadcasting range. Re-broadcasting is new, but it is no sudden development. It is the result of years of painstaking work by engineers of the Westinghouse Company under the direction of Frank Conrad. Thus far most of the work of the ex- Perimenters has been done with a non-

3 5, | | : | the Pace in Ra By Jack Binns Beginning with this issue Mr. Binns will keep you in step with the very latest developments in the swift progress of radio, as they occur each month. Every reader who has followed his intensely practical articles tn POPULAR SCIENCE MONTHLY knows that he is peculiarly qualified for this service. Fifteen years ago Jack Binns, then a wireless operator, sent out from the sinking steamship “‘Republic”’ the first *‘CQD”’’ distress call in history, saving 1650 lives in the first wireless rescue at sea. Since then he has kept abreast of radio durin§ its spectacular develop- ment, and today he is America’s most popular writer on the subject. directional aerial at station KDKA, Pittsburgh. Now a novel type of aerial is being developed for still greater effi- ciency in radiating the short waves toward KFKX at Hastings, Neb., the re-broad- casting station, and across the Atlantic to England. Recently the short-wave relay was used in broadcasting a program from station WJZ in New York City. A telephone wire carried the program to station WGY, Schenectady, whence short- wave transmission carried the signals successively to KDKA, to KFKX and to KGO at Oakland, Calif., thus covering virtually the whole country. The important thing is that the pre- liminary work has been completed, and the possibilities defined. It will not be long before one broadcasting station can be linked up with all others. Then any speaker can “‘tell the world” in reality. Broadcasting on Wheels NOTHER kind of broadcast relaying that will supplement readily the one just described has been developed by receiving camera that transforms the modulated radio waves into light waves and afterward imprints them on a photographic negative

f 7 di engineers of the General Electric Com- pany. This consists of a mobile broadcast plant of low power that is used to pick up programs from remote points and relay them by radio to the main transmitting station. A wave length of about 110 meters is used. This is far below the range of or- dinary receiving sets, so that no inter- ference is caused. The small transmitting set is mounted in a covered automobile truck permanently wired for operation. It can be run directly to the place where the program is being given, and put in operation within a few minutes. This is an advantage over the wire connection, since it usually took hours to prepare the latter and test it for quality transmission.

Fire-alarm signals by “wired wireless” have been introduced in London. The radio transmitting apparatus within the alarm box is connected with electric-light wires and with the ground. Pulling the alarm lever rings a bell at the fire station and registers the box from which the signal is sent

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Oversea Phone Service N IMPORTANT radio development, which is expected ultimately to give us commercial telephone service with Europe, is the so-called “side band transmission,” which is taking place every day between Rocky Point, L. L, POPULAR SCIENCE MONTHLY practically unknown. our leading industries. Now it is one of Last year one corporation alone sold $22,500,000 worth of broadcast receiving apparatus, accord- ing to a sworn statement. There is no Radio fans soon will be able to record concerts and speeches received by their radio sets, it is claimed, by the invention of the apparatus shown above, which makes a permanent record on a magnetic wire. Ethnologists of the Smithsonian Institution at Washington, D. C., are seen using the instrument to make a record of a Sioux Indian song and England on a wave length of 5000 meters. For more than a year the experimenters have been obtaining transmission and reception data every day, preparatory to the establishment of a regular service. They are using a system that deliberately suppresses the carrier wave. The result is greater efficiency and more selectivity with less power. Telephonic conversa- tion across the Atlantic can be made in daytime by this means with 100 kilowatts. doubt but that the others combined sold as much again. Just think of it—a $45,000,000 business growing up in two years! Other radio statistics are equally im- pressive. There are 563 licensed broad- cast stations, and upward of 5,000,000 receiving sets. More than 10,000,000 per- sons listen in every day. More than 250,- 000 persons are employed in radio work by 3000 manufacturers, 1000 jobbers, and 25,000 retail dealers. An Aid to Cable Service i pinaster radio will come an era of speed and efficiency never dreamed of in transoceanic communication, in the opinion of Major-General George 0, § Squier, retired, former chief signal office; of the army. Not that General Squier is predicting the supplanting of the cable by radio, On the contrary, what he urges is the use of radio apparatus in conjunction with the cable. Through the employment of vacuum tubes, he stated recently, ampli- fication by several stages of the received cable signals could be effected, thus opening a new range of cable efficiency, Developments in Europe HE progress of radio abroad proceeds apace, although at a slower gait than in this country. The latest countries to consider the establishment of national broadcasting are Finland and Brazil. Switzerland has given up the idea of | | erecting a central national station, and instead will build several stations, probably at Lausanne, Geneva, Zurich, and Basel. The engineers of the British Broadcast Company are attempting to broadcast the song of a nightingale. A microphone and small broadcast station have been secreted in a grove frequented by the birds. The Radio Party Line ECENTLY the radio “party line” made its appearance. Dr. A. H. Taylor and L. C. Young, of the Naval Laboratory at Bellevue, Md., have de veloped a method by which several re ceivers may be hooked up to the same aerial and function independently, re ceiving signals on different wave lengths simultaneously, even Radio Surgery OW comes the radio knife for surgery! This latest marvel was used in a Chicago hospi- tal recently in two can- cer operations. The “knife” resembles a needle. It is connected electrically with a radio transmitter that pro- duces high-frequency current. It thus becomes one electrode. The other is connected with the patient’s body. Human tissue, of course, offers resistance to electric current, and sufficient heat is genera- ted to cause the “‘knife’”’ to burn through the skin quickly. The incision is bloodless, for it is cau- terized immediately. A Huge Business gested grip on the public is almost un- believable. Two years ago, so far as the public was concerned, radio was Here is shown Alfred H. Grebe, widely known radio inventor, with his new in- vention, the “‘clarifier.”’ any regenerative receiver, its inventor claims, it will absolutely prevent radia- tion, or “‘re-radiation”’ as it is sometimes called, thereby eliminating any chance of causing annoying squeals in other receivers in the neighborhood. Hitched __* aes Hitched up to up to any kind of receiver, it is said to supply its user with stronger signals, improved selectivity, increased quality of signals, and a longer receiving range. The clarifier will work with all types of tubes, can be added to any set with- out wiring changes, works with either long or short aerials and covers the en- tire broadcasting wave-length while the aerial is being used for transmission. This is made possible by what they call a “coupling tube unit,” which is connected be- tween each receiver and the antenna. Detailsare not yet announced. “Ringing Up” NGINEERS of the American Telephone and Telegraph Company and the Western Electric Company recently de- veloped a method where- by one radio station can call up another by ring- ing a bell. The first application of the new system of ringing up by radio un- doubtedly will be to commercial wireless work. It would be high- ly useful, too, in inter- communication in a na- val fleet. Some day we all may be ringing 4 radio bell in our neigh- bors’ homes just as wé do by telephone. range

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ce era of reamed in the ‘ge 0.8 _ officer dicting radio, the use n with nent of ampli- eceived |, thus ciency, ope roceeds rit than tries to 1ational Brazil. idea of | station, tations, Zurich, oadcast oadcast rophone ve been by the 1e y line” A. Hj 2 Naval ave de- reral re- he same ‘tly, re- lengths y, even is being ission. possible call a > unit,” ected be- iver and otails are ed. Up” of the elephone Yompany Electric itly de- dd where- ition can by ring- plication stem of adio un- be to yireless be high- in inter- in a na- > day we inging 2 ur neigh- st as we > se Confessions of a Used-Car POPULAR SCIENCE MONTHLY As made to Leslie V. Spencer, M.E. job for a while with a very successful gyp ina large Eastern city. At the time I took it I didn’t realize just what ajob it was. It didn’t take me long, though, to discover what kind of an establishment I was in, and I got out as soon as I found another job. The things I saw in that place made my hair curl, and I’m telling them now in hope they'll serve aS a warning to people who are thinking of buying second-hand cars from dealers they don’t know. There are two kinds of people in the used-car trade—legitimate dealers and “gyps.” The legitimate dealers require no explanation. They trade in used cars just as honest people all over the world trade in other articles of commerce. They’re in the business to make money, of course, but they make it honestly by giving their customers value and satisfaction to the best of their ability. The used-car gyps, though, are entirely ] USED to be a gyp. At least I had a mechanics and painters got through with them, they looked like real bargains—as far as outside appearances went. As to the service they’d give, that was some- thing that Charlie didn’t bother about. A lot more time and care were spent on making the cars look right than on mak- Tesi. When the dishonest dealer tries to sell a worn-out car as a practically new model, the engine always is beautifully clean, the body glistens in a brand-new coat of paint, and the tires are painted to look like new a different class. You’ll find the word “gyp” in the dictionary, which says it means a “‘swindler or cheat.” In acquir- ing and selling used cars the gyp aims to give nobody a square deal. His sole purpose is to turn over a usually worthless article as quickly as possible for the largest possible amount of money. If he tan disguise an automobile that’s really fit for the junk pile sufficiently to sell it to some unsuspecting person for a thou- sand dollars, he’s put over a “good” deal. That the car stops, never to start again, after going a hundred miles, bothers him hot a bit; for the gyp is almost a fanatical believer in the old maxim of law and business —““Let the buyer beware!” THE boss of the place where I worked was called ‘Charlie.’ He had two floors in the automobile district. he ground floor was like any ordinary garage, but upstairs it was quite different. (Je cars that Charlie and his gang icked up” were run up to this second floor on an elevator, and, when we ing them run right. Charlie had learned from _ experience that if a car had plenty of shiny paint on it, the green buyer was likely to take its performance on faith. The condition of a car when it came in and where it came from were by no means as important as the selling end. Once the engine was “‘doped’”’ with high efficiency gasoline and with heavy oil to silence the rattles so the car would run through a demonstra- tion, and the body was fixed up with paint, advertisements would be run in several of the daily papers. It rarely took more than three or four days to sell a car after it had come from the upstairs shop. "THERE were always cars going in and out, and I learned the history of some of them. For instance, a hard look- ing fellow drove in one day with a Packard touring car that was a fairly late model, but pretty badly used up. The mudguards were badly twisted, the windshield was cracked, the metal sup- ports of the top were bent and broken, the top itself badly torn, and the car was covered with mud and dust. This fellow told Charlie he had “picked up” the car in some Southern state. He was walking along a road, he said, when the car suddenly skidded and The used-car gyp does just enough work on a car to enable it to run out of his shop. His sole purpose is to turn over a usually worthless article as quickly as possible for as much money as he can get turned over into a ditch. The owner, un- hurt, walked away to look for a farmer to pull out the car. He was scarcely out of sight when a farm wagon drove up from the opposite direction. The man who brought the car to Charlie immediately got an idea. He stopped the farm wagon, told the farmer he owned the car and offered him $10 if he’d pull it out of the ditch. FEW minutes later the car was again on the road, and, while the farmer was hitching up his team, waiting to be handed the $10 he had been prom- ised, our friend jumped into the driver’s seat and drove off. Charlie didn’t bargain with the man. He just opened his safe and handed his visitor $300. Then he put the car into the elevator. The old bus didn’t look so bad after it had been washed. Charlie destroyed the automobile license plates, and then we started to work. We overhauled the en- gine, got new mudguards and other needed parts from the service station, changed the motor number, put a new glass in the windshield and installed new metal in the top. Then the car was painted, and when the top was folded back so that the tears didn’t show, it looked ready for Fifth Avenue. Meanwhile Charlie had faked a bill of sale that would have convinced a judge that he got the car in an honest deal from a reputable man. A couple of days later anybody who was looking for a bar- gain in automobiles would have found one advertised in most of the morning papers. And when the “suckers” started to troop in, Charlie himself played the

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68 part of the broker who had lost everything in the stock market and consequently had to sell his handsome car for a song. HE “song’’ was $2000, and, when Charlie found a man who would pay it, he made just about $1600, for besides the $300 he had paid for the car it cost him about $100 to repair it. Another time one of Charlie’s scouts called up on the telephone to say that a Dodge had been virtually demolished by a In disguising an auto that’s really fit for junk, dam- aged fenders are ironed out easily and repainted to look like new street car, and that he could buy the wreck for $50. Charlie told him to grab it, and within a couple of hours Charlie’s wrecking car had hauled in the most hopeless looking mass of junk I ever hope to see. Even after we’d taken off the ruined mudguards, the body, and the two broken front wheels, there didn’t seem to be much left but wreck. The frame and the axles were bent, the springs were hanging loose; the thing looked just like what it had been sold for—junk. We finally got a little encouragement when we found the engine would run after a fashion, although the crank- case and water jacket were cracked and the radiator had some big holes in it. We puttied the cracks, straightened the radiator cells, soldered them up and poured a lot of flaxseed in with the water when we filled the radiator. After a while it stopped leaking. COAT of gray paint hid the putty on the engine and helped hold it in place. Then we straightened out the frame as well as we could without spend- ing much time on it, put on a brand new body, new front wheels and a set of new mudguards, and filled the gas tank with extra volatile gasoline. The next day the car was advertised in the papers. Charlie’s crack salesman, whose name was Jim, was given the job of disposing of this camouflaged wreck, and in three days he’d done it. He let his victim have it cheap, too—$800, with insurance thrown in, which represented a profit of $500 at POPULAR SCIENCE MONTHLY least. The buyer was well satisfied ap- parently, too. How was he to know that that smart new body hid a sprung frame that eventually would make every operat- ing part of the car go bad? Another car that came in some time later had an engine that sounded like a concrete mixer. As an experienced me- chanic, I was for taking the engine down, replacing the loose bearings and worn pistons, grinding the valves and so on. Charlie, though, had a simpler system than that. He merely had us fill up the crank- case with oil that was almost heavy enough for a transmis- sion case! It silenced all the rattles; but I’d hate to drive that car very far away from home! In another car we found two teeth out of the intermediate gear when we were putting in new grease. Or- dinarily that would be serious, but it wasn’t to Charlie. He had us shape two pieces of steel to conform as nearly as possi- ble to the shape of the missing teeth — and we screwed them into place! Then we filled the transmission case with a mixture of oil and sawdust to cushion the meshing teeth and silence the noises. We never heard from the man who bought that car. I’ll swear it didn’t run very long, but maybe he was the kind who’d rather take his loss than admit he’d been swindled. Every day you’ll see in the papers ad- vertisements that, besides offering a used car at an astonishingly low price, inform you that the car has run “‘only 500 miles.” ne, I suppose there are such cars on the market, but my experience in Charlie’s place makes me doubt it. For one of the first things we did with a car when it came in was to reduce the mileage by resetting the speedometer. A _ pen- knife inserted in the slots between the numbers and a little patience were all that was necessary to turn an old warrior that had gone 50,000 miles into a “very slightly used” car with a Beware of excessive smoke from the exhaust. or of heavy oil put in the crankcase for the purpose of disguising engine rattles speedometer that recorded a scant 500, Very volatile gas—a high test fuel such as racing drivers sometimes use—is one of the secrets of the snappy motor perform. ances which a gyp dealer’s cars give on demonstration. This fuel makes starting easier, and gives more “‘kick’’ to the whole performance. Another thing that smart gyps like Charlie always are particular about is that the battery be fully charged, Of course, the battery may be ‘“‘shot,”’ but they get by that difficulty by overcharg- ing it for the demonstration. When the plates of the battery are so far gone that not even overcharging will make it fune- tion, filling it with the acid from a good battery often will make it last long enough to demonstrate the car. jeer tapiniadgy' is expensive, and one thing the gyp hates is needless expense, Accordingly, if the platinum points in the timer are badly worn, Charlie and his kind don’t bother to replace them with plat- inum. With a sharp knife they cut little chips from a ten-cent piece, and hammer these into the points. Of course, the silver points don’t last, but somebody else has to worry about that. Often you’ll see used cars advertised as having new tires. In this case the gyp tells no untruth, but the tires are of the kind known among the gyp fraternity as “‘40-mile bolognies.”’ In fact, it’s the ex- ceptional ‘‘bolognie’’ that will last 40 miles. However, they look good—espe- cially if given a coat of white paint. Charlie and Jim both were expert actors, and they’d think up all sorts of ingenious stories to help them sell cars. I’ve told you how Charlie played the part of a bankrupt broker. That was a favorite role for both of them. Other parts they played ranged from that of a struggling young business man, who was selling his ‘ear to take his dying wife to Arizona, to that of a wealthy physician who was retiring from practice. Well, there’s a lot more to the used- car game than that, but what I’ve told you ought to cause the man who starts shopping arcund for a second-hand automobile to watch his step. If you're going to buy a used car, my advice is to go to a dealer who is known to be repu- table or to take along the best mechanic you can hire and believe what he tells you about a car, no matter how shiny the paint, how new the tires, how peppy the motor, and how low the speedometer reading. Ae you a good driver? How would you act in a sudden emergency? Next month an eminent psychologist will reveal amazing facts about yout emotional efficiency as it affects your safety on the road. It is an indication either of worn cylinders = hm wr TID

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“Timely New Ideas for the Motorist ‘icular The valve grinder arged., pictured at the left . Dut can be used in an charg- ordinary bit brace. on the Its swivel head per- e that mits it to grind yee: from _ any angle. The jaws may be 1 good adjusted to fit any t long valve with holes drilled in the head e thing (pense, }in the is kind h plat- it little ammer e silver > has to ised as he gyp of the nity as the ex- vie The tiny glass tube within the circle of last 40 Strapped to a shelf at the back of a this radiator cap indicates the water —espe- Ford car, this water- and dust-proof level, while the top opening kitchenette has 13 large compartments expert for food, utensils and toilet articles for wae an the motor tour. The door, equipped a ane with folding legs, serves as a table the part favorite rts they ruggling ling his zona, to ho was serves as a funnel for filling This gasoline gage replaces the regu- lar Ford tank cap. The in- dicator rod slides through : / ‘ an opening in the cap and A motorist’s cap with two visors. has a cork ball at the end When the lower visor is unsnapped and pulled down, it shields the driver’s eyes from glaring headlights 1e used- at I’ve an who nd-hand f you're ice is to be repu- nechanic tells you he paint, e motor, reading. Air admitted into this globe on the radiator cap is moistened by steam and conveyed to the carburetor wv would »rgency? hologist ut your sts your he road. Thebattery connector No key is needed to show n To keep out cold air in winter and lock this ingenious new above 1S hot air in summer, these rubber automobile door catch. designed sheathings for Ford pedal slots have Pushing down on a or €asy re- S been designed for greater comfort button on the inside ms moval from any terminal, no matter to the driver. They are set in frames handle, as shown above, how corroded. The device is locked bolted to the lower of the two floor locks the door when it is linders m place by tightening the large nut. boards through which the pedal slots closed. A special key is rattles Sening the nut frees the grip are cut, and hug the pedals closely The lock mechanism required to reopen it

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70 SPOUT that cannot be lost, since it is always attached to the can from which the pouring is to be done, is shown in Fig. 1. Any tubular sheet metal that will fit the cap POPULAR SCIENCE MONTHLY Practical Suggestions for the Auto Owner Bt shade is beveled off to fit against the car body, i ; The upper end of one or more of the strips should be screwed, if possible, to the top as an additional brace. Otherwise the ends are cut off flush. of the reserve oil or gasoline can is inserted after the end has been expanded slightly to a cone shape and a bead turned up around the pouring After inserting this, the bead is again es The upper end of the tube is 4 flanged slightly to avoid its slipping inside the can. cap. pressed into shape. HE windows of sedans and coupés often develop annoying rattles after the car has A suitable and easily been run for some time. made anti-rattler is shown in Fig. 2. This is simply a small circular piece of rubber about 1 in. in diameter and 14 in. thick. A hole is punched through it slightly off center. With a small burr or washer on top and bottom, this is screwed to the center of the WOODEN window frame. , By turning the disk so that pressure is ap- plied to the glass, rattling is prevented. HANDLE —_ TWO RODS BOLTED _ TOGETHER OR lapping eylinders it is possible to use an old, loose - fitting piston for the cylinder block you are work- ing on. Fit a connecting - rod to it in the usual manner and fasten a second connect- Fig. 3. ing-rod to the first, as shown in wig. 3. oA handle of wood or metal through the wristpin bear- ing in the sec- ond connecting- rod is used to rotate the pis- ton. By smearing the piston with valve - grinding compound and partially work- ing the piston back and forth by twisting the handle and pushing the piston in and out of the block at the same time, a good smooth job can be done as easily as with a more expensive tool. Old piston makes good lapping-tool MCTAL STRIP TO FIT LUG_ BOLT Fig. 6. Tightening ring lugs with tin strips GOOD-LOOKING automobile sun visor (Fig. 4) can be made in the home workshop for as little as three dollars. The first step is to make a paper pattern that will serve as a guide for cut- ting the two brackets from heavy galvan- ized iron. Satisfactory dimensions are indicated in the accompanying illustration and the best angle usually will be found to be about 20 degrees from the horizontal. CONNECTING= The motorist who looks after small repairs him- self saves money SCREWED TO TOP OF WINDOW Fig. 4. An enameled board, supported by gal- vanized iron brackets, forms this neat sun visor JONG WIRE LOOPS Fig. 7. With loops of wire the loose and worn joint of an oil-feed pipe may be made tight After each plate has been bent as shown by the dotted lines and the rough edges have been filed off, the brackets are screwed to the uprights on either side of the windshield. The visor itself may be made of clear cypress or pine. The board is planed down to a thickness of 3g in. and both sides are scraped smooth. It should be cut to length so that it will fit the brackets accurately. Three or more copper strips are set flush in the upper surface of the shade to prevent warping and the back of the The top of the shade and the brackets are fin- ished with black enamel and the under part js enameled with a smooth, glossy coat of green. [N GRINDING overhead valves contained ina removable cage, it is sometimes difficult to re- move the valve spring pins on account of the light weight and small size of the valve cage assembly. The attachment shown in Fig. 5 will assist in overcoming this difficulty. HEN the rim-lugs of a car get worn, they cause much annoy- ance by the noise they make every time the wheels go round. As it is some- times impossible to secure new ones at once, a temporary repair may be made as shown in Fig. 6. Take a strip of heavy tin or sheet iron 5 or 6 in. long and the same width as the rim - lug. Punch a hole in one end _ the same size as the bolt through the felloe. Lay the strip on the lug so that the hole will come right for the the strip so that Fig. 5. Simple fixture for removing spring pins to the shape of the lug. HILE ex- amining a friend’s auto- mobile, I found he had the up- per end of the oil-feed pipe wrapped with tire tape to stop a leak. On un- covering the pipe I noticed that one side of the coupling shoulder (Fig. 7) was almost worn off. The shoulder was originally as in A, but had worn to the shape of B. | ran a loop of wire under it and fastened it by twisting the ends. As this twist made one side higher than the other, I fitted on another loop of wire so as to make it even. Fig. 8. Crumpled paper holds wrench shim in place fare or rusted nuts in inaccessible places are often difficult to remove. It is possible, of course, to shim an open end or socket wrench to pull them off, but it is hard to keep the shim in the wrench while placing it over the nut, as in Fig. 8. This can be accomplished by stuffing a wad of paper in the wrench to hold the shim. The paper is compressé as the wrench is tapped over the nut. bolt and press | it will conform @

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Cr body, hould tional re fin- art is on. d ina to re- e light 2mbly. sist in ar get annoy- ‘y time some- W ones nay be a strip 7 tin or n 5 or6 and the idth as n - lug. . hole in id the ,e as the through pe. Lay p on the that the ill come for the 1d press p so that conform shape of [ILE ex- amining d’s auto- , I found 1 the up- 1d of the ad pipe ed with pe to stop On un- ring the I noticed ne side of coupling der (Fig. as almost off. The lider was ially as in » of B. ; fastened it -wist made iT, I fitted to make it naccessible to remove. m an open them off, him in the the nut, as plished by wrench to om press e nut. POPULAR SCIENCE MONTHLY ome Workshop Arthur Wakeling, Editor Building a Money-Saving Icebox By L. K. Wright Refrigerating Engineer N PURCHASING icechests, often ] the governing factor is the exterior appearance rather than the insula- tion. Yet it is the insulation that deter- mines the quality of the box. The old theory of utilizing a so-called “dead air space”” has been exploded. It is impossible to prevent large eo awe of air from circulating because the difference in temperature at the top and the bottom causes motion. Most modern manufacturers use some substance of packed cellular formation, which incloses myriads of tiny cells. These minute spaces, often seen only under a powerful glass, are thoroughly sealed cells and therefore inclose air spaces that are actually ‘“‘dead.”’ It is the melting of the ice that produces cold. In changing its state, ice absorbs heat. One cannot expect, therefore, to obtain cold temperatures without having the ice melt, but it is unwise to put ice in a temperature to which the heat of the room has easy access, as is the case with 2-11" —_——» aa DIMENSIONS OF BOARDS REQUIRED TOP FOR ICE CHEST OF 3/4’ on Ze STOCK} l+— 167" Ye THICK be 5-1 54->\ in s Ce at HINGE PINS bes La = 15/4 —~4 GALV. IRON LINING I" THICK CORK 2° THICK CORK ICE-DECK BAFFLE BROKEN JOINTS OF CORKBOARD INSULATING PAPER 34 BOARDS wo. ah SSH FoR “a fil Ig See tee ees ee tees i WENGE RON > 4 U ‘ LEGS 3" WIDE Fig. 2. Dimensions of wooden shell and view ng cork insulation, ice deck and baffle some of the poorly built refrigerators on the market. The icebox illustrated is one that gives far superior service to the average cheap icebox. At the same time, it is not difficult or expensive to build. Any handy home worker should be able to construct it, ex- cept possibly the sheet-metal work, and that will be done reasonably by any tin- smith, as it involves only the simplest type of soldered work. It might be well to review a few facts about home refrig- eration that will be of value to every one planning either to buy or make an icebox. i 3" SPACE MT Mh Fig. 1. Broken-away view showing the general construction of the icebox well built commercial refrig- erator, a lower temperature may be maintained. This, varying with the temperature to which the outside of the box is subjected, will be from 46° to 40° F. or even lower. The number of ice charges under average conditions with a first class icebox will be about half the charges ordi- - narily used. An _ ice- chest usually is given about 250 charges a year, where no steam heat is questions: Does my icebox waste ice > ture in my refrigerator always low enough? of air within the chest. MPORTANT to every householder are these two Is the tempera- A reduction in ice bills, in some cases amounting to from $15 to $30 a year, and at the same time a lower and more constant temperature are claimed by Mr. Wright for the homemade icebox he describes. cret lies in the method of insulation and the circulation employed. In steam- heated apartments chests require filling nearly every day, say 350 charges. With the box described, the fillings should average about 180 a year. Charges are best made with 50-lb. ice cakes. Ice The se- For every degree the temperature can be lowered, the period of preservation of foodstuffs and milk is prolonged. It is well known that at 98° F. bacteria multi- ply vastly more rapidly than at 70° F. Cream can be kept sweet a long time at from 40° to 45° F. because lactic acid bac- teria stop multiplying at that tempera- ture. At 32° F. bacterial development practically ceases. Most iceboxes maintain a rather high temperature, say about 50° F. With a box such as is described, or with an especially requires about 144 B.t.u a pound in changing its state. With a 50-lb. cake this indicates a refrigerating value of about 7200 B.t.u. every 24 hours. Under average conditions this icebox should use about 3000 to 3500 B.t.u. A 50-lb. cake of ice costs from 20 to 30 cents. This is clear evidence of the value of having an efficient icebox. I have used corkboard as insulation because its close non-fibrous structure makes it waterproof. It withstands moisture to a greater extent than other (Continued on page 104)

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72 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Neat China Closets that Are Easy to Build By Edwin M. Love B rom ms corner china closets are now much in favor, especially in small dining-rooms. Any handy man can construct them in unused corners and they not only increase the cupboard space of the house, but also improve the appearance of the room. They should be built preferably in pairs, in corners oppo- site one or more windows. The cupboard illustrated is 2 ft. 6 in. wide and 6 ft. 81% in. high, inside the jambs. The width may be varied as de- sired, but the height should be the same as that of the inside doors in the house. The top of the countershelf should be 3 ft. from the floor. Any style of trim may be used around the cabinet "£40 without change in the other parts. Omitting the casing material, which should match the trim of the room, the white pine stock required for a single cabinet is listed below. It all should be sized two sides TRIMMER aoe i required for building one cabinet is about 18 hours. First lay out on the floor in the corner to be used a line lying at an angle of 45 degrees with the walls at such a distance At right: The finished corner china closet. Be- low: The rough framework. Pref- erably a pair of closets should be made to insure a balanced effect, although one alone looks well in a small room TO CEILING -— and everything but the first item should be either machine or hand sanded. lL 3 pe. 2 by 4 in. by 16 ft., for studs 2 pe. 1 by 2 in. by 18 ft., for cleats and sub- jambs 2 pe. 1 by 3 in. by 18 ft., for jambs 1 pe. 1 by 12 in. by 8 ft., for shelves 1 pe. 1 by 12 in. by 12 ft.. for shelves 1 pe. 1% by 214 in. net by 12 ft., for door stiles and upper rails 1 pe. 14% by 214 in. net by 14 ft., for sash stiles and upper rails 1 pe. 14% by 214 in. net by 6 ft., for jamb rails 1 pe. 14% by 3 in. net by 6 ft., for door and sash bottom rails Other material needed is as follows: Hil) ee f =| Some 1 pe. 54 by 6 in. by 3 ft. pine, round-edge baseboard 1 pe. 3% by 6 in. by 14 ft. pine 1 pe. % by 2 ft. by 2 ft. 3-ply pine panel veneer 2 lights, double-thick glass 11 in. lin. 4 11l%-in. glass knobs 2 elbow catches 2 forge catches 4 pairs 219 by 214 butts 1 pe. plaster board, 2 by 3 ft. HEAD TRIMMER —— CHINA SHELF by 2 ft. in. dull brass loose pin METHOD OF LAYING OUT BRACKET ELLIPSE SASH DOOR CHINA SHELF Y ELLIPTICAL BRACKET ie nie 1g x25 f SyAMB OUNTERSHELF P-RAIL J PANEL BOOR 2-6: SHELF 1a! *crite DETAIL OF PANEL DOORS y o SECTION THROUGH FRAME Sectional view through the front, and details of door, countershelf, and ornamental bracket The cost of materials in my own locality (Alhambra, Calif.) is about $10. The time 4 = fry TACK Ry that the line is 3 ft. 31% in. long, from plaster to plaster. Plumb lines upward from its ends and cut in a 2 by 4 in. floor and ceiling plate. Next cut two pieces of studding to fit between the plates, and rip from each a triangular strip, cutting on a true miter of 45 degrees. Nail these strips to the plumb lines on the walls, being careful not to break the plaster. Cut between them, at a distance of 6 ft. 10 in. from the floor, the double head trimmer indicated above. The back edges of the ends must be mitered to fit the plaster. Cut two more pieces of studding to fit between the bottom plate or floor cleat and the trimmer head, and nail in place. The posts built up in this way have tri- angular cross sections as shown in the countershelf detail, at the left. Two short studs divide the space above into three equal sections, over which the plaster board is nailed. ost | SHELF 1 GIEAT HE 3¢ in. by 6 in. board is cut in half and nailed outside the posts or side trimmers, joining neatly with the walls. If the builder desires, a ceiling may be built level with the bottom of the head trimmer, but this is not essential. Make cleats from the 1 by 2 in. stock, chamfering one lower corner of each for neatness, and fit and nail level against the walls at the distances indicated at the left. Put in shelves, gluing the joints and nailing them into place on the cleats. Keep the front edges plumb 1 1/16 in. behind the fronts of the side trimmers. This done, make the jamb out of 1 by 3 in. stock, dadoing the head jamb 3¢ in. into the sides. Then plumb lines down the ends of the shelf fronts, 2 ft. 6 in. apart, and cut square in on the shelves 1 7/16 in. deep, chiseling out the ends. Set the jamb into these notches with the front edge flush with the fronts of the side trimmers, being sure to plumb both ways and to level the head. Cut in the bottom jamb rail and the one under the countershelf (11 in, stock), notching the ends into the jambs, If the dimensions are carefully followed, the bottom shelf will project 14 in. above the bottom rail, forming a stop for the bottom of the panel doors. Case up the opening to correspond with the trim of other doors in the room. The countershelf is spliced out to bring the front edge flush with the front of the casing, and a 54 by 234 in. fascia is fitted } to project over the casing % in. at the end, as illustrated. This piece should be dropped 1¢ in. below the top of the coun- tershelf to form a margin. The shelf imme diately above the ornamental bracket js brought flush with the front of the jamb. The bracket detail gives all dimensions, To lay it out, draw a base line 2 ft. 414 in. long, erect a perpendicular to the center, measure up 81% in., and with a wire or string knotted at each end and having a length equal to the base line, strike ares through the base line, using the top of the perpendicular as a center and one half the string as a radius. Drive brads in these intersections, slip the string knots over @ them, and trace around with a pencil, being careful to keep an even tension’ on the cord. Make the bracket in halves, using one side as a pattern for the other. Nail in place 14 in. behind the face edge of the jamb. The subjambs are cut between the shelves behind the jambs, to hide the rough edges of the two by fours. Make the doors and sash out of the 1% in. stock, either joining with mortises and tenons or by means of dowels. Groove for the panel veneer in the lower doors, and cut rabbets for the glass in the sash. Hold the glass in position by light pine strips or moldings inside. Never forget that the least hammer mark or rough place shows when val- nished and enameled. Thorough sand- papering with fine grit is essential. This Pulley Device Will Prevent Clothes-Line from Sagging ECAUSE of the constant annoyanc of having the clothes-line sag and let down the wet clothes, I built this simp! elevating device. The near pulley mounted on a 1-in. pipe tee, which slides up and down on a length of }4-in. pipe inclined to the post, as shown. To rails the wash, the hoisting rope is pulled dow" and held by catching the hook over thé lower cross pipe.—J. J. BoYD.

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Id > flush , being vel the ail and l ] ¢ in. jambs. llowed, . above for the up the trim of 0 bring t of the is fitted at the ould be \e coun- f imme- acket is e jamb. ensions. 4 ] 2 in. > center, wire or laving a ike arcs »p of the half the in these ots over 4 pencil, nsion’ on 1 halves, he other. e edge of yeen the hide the the 1 tises and roove for oors, and sh. Hold . strips or hammer hen var- gh sand il. Prevent ging annoyance ag and let his simple pulley 5 hich slides 1g-in. pipe To raise ulled dow? k over the HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 73 Valuable “Turned” Chair Made by Hand AX {NDING myself, like many another hb amateur woodworker, with an am- bition to build fine furniture, but with no lathe or even a large assortment of hand tools, I hit upon a method of hand turning that enabled me to make the chair illustrated. The ‘turning’ was done with only a wood rasp, a Saw, a bastard file, a 3-in. chisel, and three or four grades of sand- paper. The method of shaping the spiral or twisted parts is as fol- lows: The spiral must be marked out on stock that has been rounded with plane, drawknife, rasp or knife. The spirals are laid out by means of a pattern of heavy wrapping paper in the shape of a paral- THUMBTACK PITCH 200 th | similar By Rufus E. Deering by wrapping pieces of coarse sandpaper around flat or round pieces of wood and using the abrasive as a tool. The final smoothing is done by holding small pieces of fine sandpaper in the palm of one hand and rotating the spindle with the other. The hexagonal and other parts ot the chair are worked in shape with a rasp and half-round wood file and then sanded. The chair is best made of walnut or dark hard I cut the wood. lelogram, as in the accompanying dia- gram. The base of the parallelogram is’ equal to the circumference of the stock and the alti- tude equal to the pitch of the spiral to be made. The pattern is wrapped around the stock at one end so that the sides are parallel to each other. It is held in place with thumbtacks while the spiral is marked on the stock between the parallel edges. The pattern then is moved down on the stock and the spiral con- tinued. After the spiral is marked, a shallow cut is made throughout its length with a saw. The edge of a half-round cabinet rasp is used to enlarge and deepen this cut. When it is about deep enough, the round face of the rasp is used to make the concave curve inthe turning. The edges of the depres- sion are smoothed up and the spiral is worked into shape as correctly as possible. Then the smoothing is carried further 24" re 4 ps S96 3'ps 356 Jyh 3 ZF | i Balloon-Vender Kite Is a Colorful and HE balloon kite represents a bunch of toy balloons carrying up the vender to some unknown land. The framework is the same as for the old-fashioned bow kite, with a cross piece added. A kite of this kind should be at east 4 ft. high, but care must be taken to avoid getting the framework too heavy, a common fault in all form kites. For a 4-ft. kite, the spine or vertical stick should be about 5/16 in. thick and 14 (\. wide, depending somewhat on the ‘toughness and weight of the wood. Spruce 'S excellent. The bow is thinner, as it must be bent. If the wood lies in water for half an hour, it probably will bend all nght. Spring the stick and tie a string across as for a bow. Place the bent bow ‘0 that the middle of it will come over the center of the end of the spine and drive ta °,-in. brad. The narrow edge of the Handmade walnut chair and_ details showing the construc- tion and method of laying out the spiral turnings accurately k be shaped, however, by steaming and bending straight stock or by cutting the pieces to shape out of solid or glued-up stock of sufficient size. Stock 114 in. square is used for the turnings of the chair, and the parts to be made into spirals are worked down into a round shape 114 in. in diameter. A pitch of 11% in. is satisfactory in making the twists. The pieces for the seat are from stock 114 in. thick, and for the back from 1 in. thick. All joints are glued. The back and seats are of woven cane. Cane comes in hanks of about 500 [t., which is sufficient to cane two chairs like this. The cane is woven through |- or 3/16-in. holes drilled 34 in. apart. The cane should be wet before attempting to weave it. The process of caning, while it may seem complicated at first glance, is really quite simple. Even if one has had no experience in caning, a study of a caned chair will show how it goes. Indeed, it costs little to have the caning done, if the home worker does not wish to spend his time on what is a relatively monoton- ous task. The chair may be fin- ished any way the builder prefers, but for this style varnish is not really appropriate. It is better finished with two coats of shellac, well rubbed with very fine sandpaper or pumice- stone and oil, followed by furniture wax. RTICLES scheduled for early publica- tion tell how to con- struct a Welsh dresser, pieces for the chair illustrated from some walnut tree limbs. There was one ad- vantage in this—the back and legs of the chair were cut from limbs with just enough bend to give them their shape. These may By Charles M. Miller This is the first of two articles by the foremost kite authority in the United’ States, and the author ¥ of “Kitecraft and Kite Tour- naments” a toy giraffe that can be ridden, a folding ironing-board and cupboard, a combination bookrack, a baby’s bath table, improved Chinese fame racks, and a toolkit that saves time in keeping the home shipshape. Amusing Novelty spine should stand to the front of the kite, as it is much stronger so placed. Cut a notch in the bottom of the spine to receive the bow string, which should be drawn fairly tight. Measure the two side strings, and if not equal, slip the string through the notch. When equal, wrap the spine end with string and brush on some shellac. Next lash a 3-ft. stick about 1% in. by 3¢ in. thick to the spine where the bowstring crosses and to the bow, as illustrated on page 109, curving the stick up a trifle at each end The tops of the upper balloons are the only ones that need an extra framework. Number 6 reed used for reed furniture is satisfactory for these rounded forms, as it is very light. Split bamboo is much stronger, but is harder to prepare. The reed can be used dry or wet. The bamboo (Continued on page 109)

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74 F YOU have an electric fan that will I not run or is erratic in its behavior, ten chances to one you can fix it with little difficulty and no expense. Most fan troubles, indeed, are easily remedied. What you need to know is where and how to look for them. At that, it is child’s play compared to hunting trouble in a radio set. Rugged and well built as is the modern fan, it needs to be cleaned and oiled at the beginning of each season and treated with reasonable care. A bad fall ora dry bearing, a weak brush spring or a badly kinked cord may put the best of fans out of commission. You can diagnose fan troubles roughly by consulting the chart at the bottom of this page. Often the difficulty is not in the motor itself, but in the plug or cord. The first thing to do, then, is to try a iamp in the socket to see if the “‘juice”’ is there. The next step is to guard against acci- dentally blowing a fuse or doing other damage. To do this, open the main service switchboard in the house, note which wire runs to the water pipe or “ground” and then remove the fuse plug from the other side of the line. In this insert the plug of an electric iron or a toaster or a very large lamp, such as one drawing 200 watts. Should neither line be grounded, the resistanee can be placed indifferently in either. Now plug in the fan and place a length of wire across the main terminals in the base. If there is a vivid sparking, the cord is all right. If not, there may be a hidden break in the cord, which usually can be found by bending the cord in vari- ous ways, as the spot will get hot. By looking inside the plug, you can tell whether the connections have loosened or the ends of the wires are touching each HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY How to Fix a Balky Electric Fan examine the brushes and commutator. Perhaps your fan hasn’t any; it won’t if it is of the alternating-current induction type. If it is of the series-wound commu- tator type, or if it is a direct-current motor, it will have a commutator and brushes (See Fig. 1). The brush holders can be removed, usually by loosening a single screw in each. Perhaps the brush springs are weak, as they may become through overheating. Possibly the brushes are badly worn. The commutator may be oily and dirty, need- ing to be cleaned with kerosene, and per- haps sandpapered carefully with very fine sandpaper. Clean out the slots with a pointed stick and inspect the fine connect- ing wires for breaks. If there is a burned spot between two of the bars, take out the armature and return it to the electrical dealer to be repaired. If the motor is of the induction type, without a commutator (Fig. 2), it may have centrifugal fingers that fly out when the rotor speeds up. Cleaning them usu- ally will make them work freely. If the trouble seems to be merely that the fan binds, lint and dirt may have accumulated around the bearings and need to be removed. If the armature or rotor sticks, the bearings sometimes can be re-alined by tapping their housings gently with a block of wood. This trouble is not apt to oc- cur unless the fan MO-V. HOUSE LINE nas beecem “at dropped. If the STARTING bearings are SswitcH badly worn and the spindle has too much play, the small bush- ingsineachbear- 0 ing can be re- TESTLAMP moved and new F ones inserted. Fig. 5 Now that there _— is nothing to pre- vent the fan from turning easily, and the ‘juice’ is being delivered to the motor terminals, it is obvious that there must be something wrong in the wiring itself, if the fan still shows no sign of life. The diffi- culty is to find just where'the short circuit, open circuit, or other defect is located. First test the starting or speed regulat- ing device, which may be a speed-regulat- ing coil (Fig. 3) or a rheostat (Fig. 4), with switchpoints. The easiest way is to use the electric current itself to ferret out the trouble. To do this, connect to a plug two in- sulated wires with their ends bared (Fig. 5). One of these wires should be cut and a 15- or 25-watt lamp inserted to act as an indicator. The elec- tric iron or other large resistance used to protect the main house circuit should be removed while this testing circuit is in use. Test the various terminals by touching two of them at a time with the bare wire points. If the lamp lights, the circuit is all right between the points being tested. If it doesn’t light, it is a simple matter to narrow down the hunt to the point where the break has occurred. If the speed regulating coil or coils are all right, the diffi- other; either defect can be remedied Fan Trouble Will not run at all Blows fuse Cut off sev- Sticks easily. eral inches of cord, if necessary, and re- connect the plug, or Buzzes only substitute a new eord throughout. Once you are sure the “‘juice” is actu- ally reaching the fan terminals and the Runs jerkily Probable Reasons Open circuit and Short circuit plug, cord, “‘short’”’ is detected Clean thoroughly, bell, if necessary; and line up bearings; grease well Check up each possible cause and correct by cleaning, replacing de- fective parts or reconnecting open Dirty or bent parts Centrifugal fingers bind; burned or dirty commuta- tor; defective brushes; open circuit in armature winding circuit Brush does not touch com- mutator; loose connection; open circuit in armature How to Repair Troubles at a Glance and Their Cure | Use test lamp in step-by-step check | up of circuit, beginning with cord | resister or starting switch. Reconnect when break is found Put resistance in line and examine | and connections, | placing or insulating part in which | Look for sparks, which usually re- veal point of failure. Reconnect or replace defective part culty is in the motor c- | removing end straighten parts itself. The wire in the windings rarely breaks, so that the open circuit will be found almost cer- tainly at soldered connections or loose ends. Examine all con- (Continued on fan still won’t run, page 100) _~ Ae gt ORL lle _ -_ es -.h Uc6lelhlCCelCU6lhlhCUe: 6. Oe

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in y that r have Sand ture or es can USiNgs rouble E aaa rm TOR A\NALS IELD OIL SRUSH RMATURE RUSH a) init \ By = POPULAR SCIENCE MONTHLY eae nT rT Hi fy ue ‘f vitiietintd é ’ 4 4 dui shades are: FIELD OIL nd the motor aust be f, if the e diffi- circuit, ted. egulat- egulat- heostat \points. use the o ferret Jo this, (wo in- ir ends of these id a 15- rted to he elec- used to ould be s in use. ouching ure wire ircuit is tested. atter to t where ‘oils are ie diffi- e motor wire in s rarely hat the will be yst cer- soldered or loose all con- d on 60) It Tells — 4 ie How to finish soft : and hard woods. How to stain wood Oak No. 131 Walnut artistically. How to remove old paint and var- nish. How to secure a beautiful enam- el finish. 75 Johnson’s Wood Dye comes in all sizes from half pints to gallons. Among the sev- enteen popular No. 128 Light No. 110 Bog Oak ’) JOHNSON's Woon Dvt Fumed Oak NO. 120 woop rimsnine AeTHORITES Yi Mahogany No. 129 Dark Mahogany . No. 127 Brown Mahogany || No. 123 Dark Oak Ai\i | No. 126 Light Oak hiv ( ~«~No. 124 Golden If you have a hobby for making cabinets, eit porch swlidinwedlee er etc.,— you will find our Book invaluable. Naturally, you want to give your handiwork a beau- tiful finish. Our Book gives complete instructions for finishing all wood—hard or soft, old or new. It is the work of experts—beautifully illustrated in color. capacities—includes color charts, etc. Use coupon below. JOHNSON’S Johnson’s Wood Dye has many uses, for both the artisan and amateur. Architects and contractors specify it for coloring woodwork and flooring in new buildings. Painters and decorators use it with equal satisfaction on new and old wood- work of all kinds. Housewives delight in it for doing over old furniture and for coloring reed and wicker baskets, etc. Manual training teach- ers and pupils use it for finishing their mod- els. Upholsterers, furniture repairers and Cabinet makers find it ‘“‘just the thing”’ for their work—old and new. S. C. JOHNSON & SON “The Wood Finishing Authorities”’ Racine, Wisconsin, U. S. A. 7 —, | SERVICE PP pea: | DEPARTMENT partment, mail this coupon to us WOOD DYE Gives covering Johnson’s Wood Dye is very easy to apply—it dries in four hours and will not rub off or smudge— penetrates deeply, bringing out the beauty of the grain without raising it. Made in seventeen popular shades all of which may be easily lightened or darkened. Full directions on every label. Read and follow them PPS eee eee Ask for a FREE copy of the Johnson Book on Wood Finishing at any store displaying the sign shown at left. If no store in your locality has a Johnson Service De- ee ook a acs sedan ere cwedenwaene emeaemien Your Name... Sb odin wim E PharkaceeR en eeee aaa aden [0 ee : cove, ot lag orahetererenereqiay elma eames ORG Met MORAN ROM OME vc 50. o: or s)'sl'oieiviel'eno'sia 0.8\ol atl avererelaloneleele sarmiaiaars Mail to S.C. JOHNSON & SON, Dept. P. S. M.7, RACINE, WIS. fan Sc REE

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POPULAR SCIENCE MONTHLY Better Shop Methods, How Expert Mechanics Save Time and Labor ta Secrets of Cutting Threads Successfully By H. L. Wheeler and Henry S. Laraby OE was having a hard struggle with a J simple threading job. Several times he had broken his threading tool, and he was trying to reset it when Old Bill came over to see if the job was finished. With some signs of nervousness, Joe started the lathe again. Perhaps if Old Bill hadn’t happened along at this very moment, things might have gone better, but some men do get a sort of sinking sensation when the boss comes along, especially if they are bungling their work. This is what Joe was doing with his threading, for the tool had crossed the thread. Old Bill was far from pleased, because he had promised the job by noon. To tell the truth, he had been tempted more than once to let Joe go, but he had a kindly feeling toward the young mechanic. He understood, with the tolerance and broad vision of a man who was genuinely a master of shop practice, that mechanical 129%! See Gay SETTING CENTER) LINE ability cannot be gained overnight; there- fore, he was always willing to straighten out the work of any machinist who showed the least interest in learning better methods. This particular job was a trifle out of the usual run. “Just stand by and watch what I do and how I do it,” Bill said, as he put over the compound rest at an angle of 30 degrees and set the tool square and on center. His next move was to engage the nut and run the tool along to about the middle of the thread. “This takes up the back lash,’ he ex- plained to Joe. Y MANIPULATING the cross-feed and the compound rest, he soon had the tool perfectly meshed in the old track. He tore a sheet of white paper from his notebook and held it under the tool. “Look down at the top of the tool, Joe. Do you see any white through the sides of the tool?’’ Of course Joe did not. “You see,’’ Old Bill went on, “‘the point of the tool is now at the bottom of the cut. We'll set the stop at this point, and we are ready for business.” Bill backed the tool out and reversed the carriage to the starting point by dis- engaging the nut and running it back with the hand feed. He put a chalk mark on the faceplate near the edge of the way and one on the way itself, close to the carriage. Then he ran the cross-feed into the stop and moved the tool in .003 in. with the compound. The lathe was started and Bill smeared the thread with oil. The tool peeled off a nice smooth chip as it ran to the end. Here Old Bill pulled the tool out quickly with the cross-feed handle and stopped the lathe, at the same time throwing the nut out again. He turned the spindle by hand until the chalk mark came around to the right position and ran the carriage back to the other chalk mark. He took another cut in the same way and then stood aside to let Joe take hold of the job again. “You will notice, Joe, that there is no burr on top of the thread and the cut is quite smooth,” Old Bill remarked. ‘That is due to the fact that the tool cuts only on one side and is ground with a slight slope toward the back. I guess you’re on the right track now. Next time be a CENTER Method of setting in- GAGE ternal thread tools, and : a handy gooseneck tool FIG.5 little more careful. That oil you are using is quite thick. You’d better thin it out with some kerosene and you’ll get better results.” With this, Old Bill left Joe to finish the job. After all, thread cutting is Old_ Bill, considering his promise of immediate de- livery, decided to salvage the piece. He told Joe to take it to the smith shop and have the welder stick some metal on the spot where the thread place. Old Bill Says— ID you oil your lathe this morning? Oil costs money, so see that every drop is put in the right was damaged. Talking about oil—a little on “Get back here just as one’s manners helps a_ lot. quickly as you can and dress ey omnis “She day's it down to size,’”’ he added; “then come and tell me when you have it ready and I’ll show you a few kinks about thread cutting.” After Joe had the job all set again, he went for Old Bill, who took hold of the lathe. Be sure of your set-up before you start to cut. The shop pest is he who is always borrowing tools. your own and be independent. To do unnecessary work in a shop is a waste. find the easiest way. If surface plates could talk, many a one would say, an anvil!” The fast worker knows when to take time. It pays to “Tam | a straightforward operation when a few simple rules are known and observed, but some mechanics tackle 4 threading job in the fear that they will not be successful. This fear was Joe’s principle trouble. The first thing to do is to gain confidence and master a few simple rules. The explanation of Old Bill’s method for catehing 4 Buy thread is this: By having the work and the screw in the same relative position with the starting point of the tool, the nut may be disengaged at the end of each cut and run (Continued en page 88)

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2d into 003 in, meared d off a e end, quickly topped ing the ndle by around arriage le took id then the job re is no e cut is “That its only a slight yu’re on ie be a — TOOL NECK LDER = ing in- ols, and eck tool re using n it out t better -o finish itting is peration ‘ules are ed, but ackle @ fear that ecessful. principle ing to do nce and rules. of Old tehing 2 ving the y in the ‘on with the tool, gaged at and run re 88) POPULAR SCIENCE MONTHLY Ske L.S. STARRETT COMPANY orld’s Greatest Toolmakers MANUFACTURERS OF HACKSAWS UNEXCELLED CATALOG No. 23 Hot off the Press THE NEW STARRETT CATALOG N2. 23 W is now ready for distribution. Shows all the new Starrett Tools which have been added since our last catalog was published, many of which are here listed for the first time. Get your copy atany HardwareStore selling Starrett Tools or write us. THE L. S. STARRETT CO. The World's Greatest Toolmakers Manufacturers of Hacksaws Unexcelled ATHOL, MASS, for instance Angle Gage Hold Downs Extension V Base for Jack Screws Rolling Mill Gage Drill Point Gage Flexible Stainless Rule Cylinder Gage Pocket MicrometerCase Dial Bench Gage and some fifty others

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BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY Cutting Down Shop Casualties The price of a moment’s care- lessness. The operator allowed his glove to catch between the work and the drill, and his hand was badly crushed. At the same time the drill literally ripped the clothing off his body. This shows what arela- tively harmless machine can do and is a warning of the necessity for continual caution and proper working clothes. To wear loose overalls and baggy sleeves around a machine is to invite mutilation j. veny year, according to statistics based on Department of Labor reports and other official sources, 22,000 American work- men die as a result of industrial accidents. This is 45 per cent of the total number of Americans killed in the World War. Every year, it is estimated, there are not less than 8,400,000 accidents in shops, fac- tories, and similar industrial enterprises, and as a result 680,000 men are laid up for four weeks or more. Most of these accidents, experts say, are preventable. Think! Be careful! Go slow! SAFETY FiRST!

The handles on these lifting hooks are an excellent safety measure, but often over- looked in plants where heavy materials are handled. The workman can adjust one of these hooks and hold it until the crane has. started to lift without danger to his fingers This workmen’s thumb was crushed in a slot of the drill press table when the block he was,drilling started to turn. He held the work by hand as in the upper right-hand illustration instead of clamping it If the work is properly elamped on a drill press table, there is not much likelihood of accidents like those shown above. By analyzing 350,000 industrial accidents, the National Bureau of Casualty and Surety Underwriters for the Na- tional Council on Compensation Insurance, has shown that most accidents occur at the point of operation, or where tool and work meet Photos courtesy of the Natsonal Safety News Never try to hold work against a machine’s strength, as shown above. A result very apt to follow such care- lessness is indicated in the illustration at the left

Beware of falling tools. Left in unsafe places, tools may injure a person below

BA Sa PO ig rH 2 0. rss ~ OD ~~ FS er Tt UDC <_-“ fF. fF DP a a

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POPULAR SCIENCE MONTHLY gion Ae 7 = 42 $B, B>, % e Os te _ pres 2 pet Be il Z Se Ait 400 BD : pein o: oyT “) ees? i i] Enjoy Your Radio This Summer USIC MASTER with its rich, clear tone—unmarred by muffling, blast or at distortion—will make radio a pleasure such ch care- as you have never known before. istration Summer opens a new world to good radio sets equipped with Music Master. Picnics, camping trips, boating parties, open-air dances—these are only a few of the occasions which Music Master can enliven for you. Music Master is remarkably well fitted for summer conditions. The extremely sensitive precision instrument in the base, the scien- tifically tapered tone chamber, and the now - famous wood horn, the natural and perfect resonator—make up an instrument of bal- anced proportions and unsurpassed effective- ness. Your radio dealer is waiting to demonstrate Music Master for you or to send one for trial with your own set. Dealers Everywhere Music MASTER CORPORATION (Formerly General Radio Corporation) Makers and Distributors of High-Grade Radio Apparatus 10th and Cherry Streets PHILADELPHIA Chicago Pittsburgh 14-inch Model, for the Home - - - - = 21-inch Model, for Con- certs and Dancing - Connect MUSIC MASTER in place of head- phones. No batteries required. No adjustments.

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80 Here's what hfe ab Ill say (Qe 3s — aftera : .> lifetime of using them ~

" | ¥ —and you ‘~« younger fellows can take it oy leave ut, just as you choose” “I would as soon go to work without my" right hand as without my NICHOLSON Files. Through the forty years I’ve been in this shop, NICHOLSON Files have always been right on the job for me--- perfectly tempered, keen cutting and true as dies in their uniformity. “Yes, I’ve used them on both heavy work and for fine filing and found that the NICHOLSON File for any purpose is the best file for that purpose. Most first-class Hardware Dealers carry complete stocks of NICHOLSON Files. NICHOLSON FILE CoO. Providence, R.1., U.S.A. HOLS, SS ” U.S.A. (TRADE MARK)

= =] NICHOLSON FILES ~a File for Every Purpose | OSS SS SS SD j L

BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY

This Die-Maker’s Square Has Sight-Hole in Handle To die-maker’s square has been de- signed so that high spots in the sides of holes can be checked readily by looking along the blade, which cannot be done easily with the usual square. The edge of the blade is made in the shape of a MILLED OUT FINGER HOLD

"DEEP ON EACH SIDE ° ascend a | “ = 48 sro | E | = tf | x i we 1 . — 1 y_1 ae gle 2 or aarero are -” TTT |] mw ij + nus 0 ‘a TT |] FF | saan enaonnammenanans > Li | - 25 SIDE FOR GROIN KNIFE EDGE) Zz. ¥ i a 3 : By ke

Details of the die-maker’s square. Note hole through handle and shape of blade knife edge and is visible through a hole in the handle. | The bottom side of the beam is cut so that it will not catch on the opposite side

of the die when used in narrow openings, and the bolt is made exceedingly heavy | to prevent the blade from shifting. While this tool has been in use in cer- | tain shops for a number of years, it is not |

8 LOOKING DOWN THROUGH YY HOLDING WORK TO THE LIGHT AND LOOKING THROUGH Me BEAM HOLE THE HIGH SPOTS ALONG THE BLADE KNIFE EDGE ARE DETECTED.

SQUARE ©) | EDGE WONT FOUL DIE Y =Yy OPPOSITE THE WORKING SIDE Uf j/ Wy

iG Yi Yj THIS HIGH SPOT WOULD 7 PERFECT HOLE SIDE MAKE THE DIE USELESS 3° CLEARANCE Accuracy of holes is checked by sighting the blade through the hole in the handle as well known as it deserves to be among mechanics who handle very fine, accurate work.—H. L.

BRASS may be colored an antique green with a solution of 3 oz. crystallized chloride of iron, 1 lb. ammonium chloride, 8 oz. verdigris, 10 oz. common salt, 4 02.

potassium bitartrate, and 1 gal. water.

tebe 26 © Fr OO ef ft «3 Sette A. fe oe mm of 029 CP A SS > Ole CU | a

Tape ae

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das n de- sides oking done edge . of a

m & m green tallized rloride, t, 4 02. ater.

BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY

V-Block Tool for Centering Round Stock Quickly SIMPLE centering tool for centering A round stock can be made from a piece of sheet steel about 3/16 in. thick. It is used in connection with a V block. The tool has four accurate edges, two of which serve as guides in the V block and made to the same angular dimen- |nTERSECTING sions. The verti- LINES cal edge bisects the face angle SCRIBES and __ intersects the apex of the V. To use the tool, hold it against the end centering TOOL of the stock while resting in the V The centering tool block, as shown in the accompanying illustration. Mark along the vertical edge with a scriber and rotate the stock about one quarter turn. Another mark then is drawn along the vertical edge bisecting the first. The in- tersection of the two lines will indicate the center of the piece. In addition to its use as a centering tool, this device may be employed as a small square. To allow this, the vertical and horizontal edges should be at an exact right angle to each other.—G. A.

Protecting Small Levels i LINING up small machines I make use of a 3-in. pocket level. Each week one or more of these levels was accident- ally broken until I hit upon the idea of covering the level with rubber, as shown. To do this dissolve 4 or 5 oz. of crude rubber, preferably what is known as washed para sheet, in 12 oz. of benzol. This will require at least 24 hours. Place the level on - a board and apply as heavy a coat as Qi wossible by pour- : ing and brushing. oe When the coat is thoroughly dry, apply another coat and continue until all the cement has been used up. Tie a cord around the level and drop it into a solu- tion consisting of 96 parts carbon tetra- chloride and 4 parts of sulphur chloride for about 20 seconds. This immersion elects a vulcanization of the rubber. Rinse the level in water and when it is dry, strip away the rubber from the edge side and with a razor blade cut an ellip- tical opening over the glass sight.—L. W.

BUBBLE SIGH ne

Hook for Hot Soda Tank A HANDY dipping hook for the hot soda tank may be made from a length of 3%-in. cold rolled steel. It will found convenient for handling small parts aving a central hole, for cleaning greasy

Similar work.—H. W.

ee

milling cutters, and for

This test is How Men Win A significant Shaving Cream story By V. K. Cassady, Chief Chemist GENTLEMEN: Here for 60 years we have studied soap. Some of the greatest soaps in existence are of our creation. Our Palmolive Soap is the leading toilet soap of the world. Our problem was to create a Shaving Cream so superior that every man who tried it would adopt it. We brought to our laboratory every other shaving cream. We put them all to scientific tests. Then we studied to excel them in every quality desired. We made 130 shaving creams, each better than the others. And we at last arrived at what we deem the utmost in a shaving cream. Millions of men have adopted it. Tens of millions more will when they know. Just watch it act Don’t buy it—just ask fora ten-shave test. Compare Palmolive Shaving Cream with the soap you are using now. If we have done what you desire, adopt it. If not, return to the old. We ask no favors. But we do ask the courtesy of a test. Concede us that test. You owe it to yourself and to us. 5 BETTER RESULTS It multiplies itself in lather ness for 10 minutes on the face. 250 times, so one-half gram The super-strong bubbles suffices for a shave. support the hairs for cutting. It acts in one minute. Within That’s the major purpose in a that time the beard absorbs 15 _— shaving soap. per cent of water. The palm and olive oil blend It maintains its creamy full- leaves delightful after effects. To add the final touch to shaving luxury, we have created Palmolive After Shaving Talc—especially for men. Doesn't show. Leaves the skin smooth and fresh, and gives that well-groomed look. The Palmolive Company (Del. Corp.), 360 N. Michigan Ave., Chicago, Ill. PALMOLIVE a SHAVING CREAM_paa'\

\

b\ ary) NES) pews © P. Co., 1924 10 SHAVES FREE and a Can of Palmolive After Shaving Talc Simply insert your name and address and mail to Address for residents of Wisconsin, The Palmolive Company (Wis. Corp,), Milwaukee, Wis., Dept. B-828, Address for resi- dents other than Wisconsin, The Palmolive Company (Del. Corp.), 360 N. Michigan Ave., Chicago, IIll., Dept. B-828. Wa

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Set of STANDARD (ae TOOLS - ne. x \ re a) Sa Gan. = ad 7 ow w4, ox Ma “For the shop apprentice and home mechanic” Here is a set of tools selected by a master mechanic as being essential to every apprentice machinist or home mechanic who wishes to have an outfit of quality tools for a moderate outlay. The tools are neatly arranged in a felt-lined leather case that provides ideal protection from dust and moisture. Closed, the case is about 7" x 434"x 13". This set contains the following tools: 6" Tempered Steel Rule 6" Combination Square 60° Center Gauge 9/64" Center Punch 4" Rex Divider 4" Rex Outside Caliper 4" Rex Inside Caliper 4" Hermaphrodite Caliper Mechanics the world over depend upon Brown & Sharpe Tools for their quality and lasting accuracy. For this reason Brown & Sharpe Tools have been the choice of mechanics for three generations. Ask your dealer for Brown & Sharpe’s Set of Standard Tools No. 847, or, if he cannot supply you, write us. Our Catalog No. 29, listing over 2,000 tools, sent on request. BROWN & SHARPE MFG. CO. Providence, R. I. BROWN & SHARPE TOOLS BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY Fixture for Tapping Nuts in | the Drill Press | APPING nuts in a drill press is speedy | and satisfactory. A cast-iron block is made as detailed with a groove equal in width to the distance across the flats of the nuts to be tapped. A clear. ance hole is drilled for the tap. The block js bolted to the drill. press table and an ordinary machine nut tap is used in the drill chuck, Several nuts may be placed in the iin eels wen block and as fast along a_ slide as the tap is drawn up, another nut js ready to slide against the stop pin. A separate block is used for each size of nut,| —H. L. W. Graduating a Long Metal Scale in an Ordinary Shaper CIRCULAR-SAW operator needed | i a scale to go on his 12-ft. sawtable.|f It was found impossible to purchase such | a scale at a price consistent with the re-| quirements, which did not call for ex-|| treme accuracy, so the scale was made! in the shop in the following manner: The metal bar was clamped in the shaper vise, and the shaper stroke set so & that the tool would pass entirely across. the bar. All the inch graduations were cut by passing the pointed tool across| the bar. The stroke was then shortened |§ to pass only about halfway across, and the half-inch graduations were marked. | The stroke was shortened again to make | the quarter-inch and eighth-inch gradua- tions. The result was a cleanecut scale at a very low cost.—R. H. KASPER. Gage for Awkward Work ‘TH special gage shown below is de-|f signed for measuring in places where | f other tools would have insufficient range | or adaptability. : | The beams are movable anywhere on | & the bar and the gage can be used for in- side or outside measuring. One beam may | This gage is useful for work that is diffi- cult to measure with ordinary tools be reversed so that a long and short end can be used together. It also can be used in a vertical position for measuring | heights. The gage is made from drawn steel. | The bar should fit neatly in the slot of the | beam. A gage of this type now in use has | two bars, one 15 and the other 36 in. long. | —S. C. His, Torrington, Conn. ee a

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i: in | speedy | block | | - equal | e flats | to be! clear- drilled ck js e drill. and an achine- ised in chuck. ‘S may in the as fast ; drawn nut is yin. A of nut. Scale r needed | wtable, | ise such | the re- for ex-| Ss made | ler: | in the|j e set so y ACTOSS | ns were 1 across | ortened | Ss, and marked. | @ to make | gradua- ut scale SPER. ork w is de-| es where | § nt range | vhere on d for in-| 2am may | s diffi- tools ‘hort end n be used neasuring | wn steel. | Jot of the | n use has 3 in. long. 1. —_— Locating and Enlarging Punches Aid in Accurate Layouts price punching a location accurately with an ordinary punch is difficult, for it is not an easy matter to hold the punch vertically without a guide. For precision work, therefore, a set of locating and enlarging punches such as those illus- trated is a valuable addition to the machinist’s toolkit. The guide points of the locating punch follow the center lines scribed in the work by means of four V-shaped scriber points instead of the more usual half V-points. The points bear on the surface of the work , MACHINE _ )" aw STEEL | KNURL FLAT... ¥ 5 th 5° N 5 ved od | a TOPE » 32 Ms 5 4 TAPS", x D or - rT. 3 — ks wth F ot Z HOLE : HARDENED EIGTHD. POINT CH. ie © DRILL ROD yk 4 SCREWS o 2 18 THD. re al] MO warvéene ~ ED ae POINT 2 TOD OF COLLARS (—) KR 2 wH--4 by \g FLAT-AT-% 5” rfl f SKNURL HARDENED pont ()i3'D. DRILL ROD \/_y¥ ; The locating punch and its parts are shown at the top and the enlarging punch below and, because of the weight of the tool, drop into the scribed lines with a click. A slight tap with a hammer then gives a sufficient impression for the location mark. The second, or enlarging, punch is not located in the same manner as the other, but is moved about on the flat bases of its four legs until the point coincides with the location punch mark. The spring keeps the point above the work’s surface until it is properly located and the punch can be tapped. Care must be taken to have the punches fit snugly in the bases and to have the axes of the punches at right angles to the base. The locating feet of the first punch must fit tightly, requiring a hard turn on the screws to force them out. A LINING for protecting tanks from the influence of acids is made from a mixture consisting of 75 parts pitch, 9 Parts plaster of Paris, 9 parts ochre, 15 Parts beeswax, and 3 parts litharge, all nent by weight. BETTER SHOP METHODS LEPARTMENT OF POPULAR SCIENCE MONTHLY ) 5 =) £ 4] ) i) Trucks General Motor Power to Pull Out— Speed on the Road! Watch for the GMC trucks on the next excavating job! Division of General Motors Corporation Pontiac, Michigan General Motors Truck Co. Pontiac, Michigan Department 47 Gentlemen:—I am interested in what GMC trucks can do in the following business:—(Check business) Notice how easily they haul their full load of earth up the steep incline to the street—unaided by cable or team. Then check up with the driver on the number of loads they haul each day. You will find them as speedy as they are powerful. For, equipped with the famous GMC Two Range Transmission, GMC Trucks multiply the power of an engine, of economical size, into pulli at the wheels that will take them up any gradeor out of any mud where wheels can get traction. And, by a shift of a lever, also provide as fast a road speed as safety permits. This combination of speed and pulling power—built into GMC Trucks —their rugged dependability and their operating economy, all make them money-makers for haulers everywhere. GENERAL MOTORS TRUCK COMPANY Lumber 0 Laundry oO Milling oO Contracting oO Transfer oO Store Delivery oO Bakery Oo Building oO Furniture oO Bottling oO Oil 0 Coal oO Other Businesses (0 Name Address

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BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY ee | Boring Bar, Expansive Mandrel, | S and Lathe Tool-Holder ‘T BREE time-saving ideas for the ma- chinist are shown in the illustration | f below. The first is an efficient adjustable bor- i ing bar, which may be made at small cost. ” | A square slot is cut through the bar to. take standard toolbits. These usually are beveled at both ends when purchased. / Holes are drilled and tapped for the ad- justing screws. The cutters may be set. roughly to size with calipers and locked | with the setscrews. They should be ground for size on centers either in lathe | or grinder, and properly relieved for | clearance. The size then may be changed | readily within reasonable limits. | An expansive mandrel is a handy lathe | § ( | accessory for turning and facing small | SQUARE CUTTER , ~~ BORING-BAR u f Z t] Z' t Yyy a SETSCREW 0 / t) i a CUTTER-ADJUSTING SCREW ve ee ea z EXPANDING PINS a Ne e Buy some good tools | C5, : it ; \' x HY pa ” y 4 a > WA ‘ ¥ s] @ yy PP y for the boy, Dad~and 1 “af . {whisper} use them yourself il cant | | F P in the attic or out in the garage | there are new adventures wait- 3 ing for the Boy and YOU —adventures a with tools in The Land of DOING 7 v Things! SWIVEL CLAMP WOOL -HoLaee P What a world of achievement good The adjustable boring-bar (above), expanding | [) | f ! mandrel (center), and lathe tool-holder (below) He! tools open up! What wonders they mi: can perform ! gear blanks or similar work. The design | F : ; : ; . i i th Begin your tool kit today with a Si- suggested in the second drawing has we le P ; round pins actuated by a hardened stee monds Hand Saw, Hack Saw and File. ball in contact with a setscrew placed’ fe |, You'll thrill to the feel of their perfect centrally at front end. The pins —_p e : sas ’ : beveled about 45 degrees on one end an Wilt qualities. You'll = each of | each should have a flat spot for a locking | them as a real tool. You'll know why setscrew. The pins are spaced 120 de- Industry has chosen them for years. —— spent eee one or two inches ’ ee | from the end. They Il make the boy a better boy | A useful boring tool-holder is the third his Dad a better man. | tool illustrated. It makes use of ones B | sizes of drill rod or of high-speed stee ut be es when nee buy oe | round stock. One end of the rod is forged or files, to say SI-MONDS. | to the desired shape and tempered as | usual for any tool. The holder consists of & SIMONDS SAW AND STEEL CO. | a piece of cold rolled steel having a V cut “The Saw Makers - Established 1832 in the top side. One end is fitted with a Fitchburg, Mass. swivel yoke having a setscrew for setting Branch Offices in Principal Cities and adjusting the tool.—H. S. L. Cutting Cost of Lanterns ONTRACTORS and others who use guardian lanterns with red shades, know the cost of replacing broken glass. ee This expense can be reduced by using the alii : OATH a 3 ordinary red dye stain made for electric- | : Sees — light bulbs. A bottle costing about $2. will color several dozen shades.

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IF OLDER iding 2low) design | three | steel nlaced uld be d and yeking | 0 de- inches third ndard steel ‘orged ed as ists of V cut with a etting 1S 10 use hades, glass. ng the octric- | ut $2 BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY Shop Coat-Rack Made of Pipe and Metal Lath A SERVICEABLE shop coat-rack can be made from short lengths of pipe and standard pipe fittings. The top is covered with expanded metal or wire G'HIGH , 12'LONG, 18" WIDE This substantial rack, which is made of standard materials, economizes space cloth and serves for a hatrack. The three uprights are of 114-in. pipe fastened to the floor by means of railing flanges. The top frame and braces are made of 34-in. angle iron, riveted together. Coats hang on conventional coat-hangers, as _ illus- trated.—A. S. JAMIESON. Handy Belt-Lacing Tool I HAVE been using this handy belt- lacing tool for the past year in a small shop for applying carded belt hooks. The tool is made by cutting a number of parallel slots in a short piece of 1¢- in. pipe with a hacksaw. The dis- tance between the slots should be de- termined by the corresponding dis- BELT HOOKS FE tance between the or carded belt hooks hooks on the ecard. A length of 12- gage wire is used as a pin to hold the hooks in place. The illustration clearly shows how the tool is used.—CARLETON SCHLESMAN, Baltimore, Md. Accurate Dividers for Shop Use HE difficulties with the average divider are the tendency of the legs to spring, the loosening of the hinge, and the slipping of the pivot joint due to the “ “ IN THROUGH —— = 7" f al j-32 DIA. 3 | 3° POINTS SR FEvpeReD | The thick, heavy legs of this type of dividers do not spring or shift in use |fact that pressure cannot be exerted | directly above it. | A set of dividers made as shown here will overcome these disadvantages. falc laa BLACK & DECKER QUARTER-INCH PORTABLE ELECTRIC DRILL “With the Pistol Grip and Trigger Switch’”’ Bench Drill- ing Stand. The drill can be in- serted or de tached quickly by means of handle clamp. $12, In Canada $16 Grinding Outfit. ~ Consists of stand which can be fast- ened to bench top, arbor with clamp washers and nut, and grinding wheei. $3—1n Canada $4 ps Ob, ee Do You Make Things for Your Own Home ? Do You Build Radio Sets ? Do You Work on Your Own Automobile ? This BLACK & DECKER, QUARTER-INCH PORTABLE ELECTRIC DRILL will save you an immense amount of labor and will enable you to turn out work to be proud of. You will find it one of the most useful tools in your kit. Order one now. . he ee earn SRN SEY Be RES Shae i Ee ee FE AY % ew " BORE To RRR aE SC See cay Rs ORR ORRREONE © oc POR APACS SAMBO Fig Re ik FESS AS Se Orders and inquiries sie be mailed to “THE BLACK & DECKER MFG.CO. 700 Pennsy!vania Avenue, Towson, Maryland Be dixp o a ye 2 ————* bi cps, ATT gps &, ee ct lia a ee : 2

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Zero hour approaches. Wire chief and assistants are set for the “cut-over” that will bring a new central office into being. In the room above operators sit at the new switchboard. Two years this equipment has been building. It embodies the developments. of hundreds of engineers and incorporates the scientific research of several decades. Now it is ready, tested in its parts but unused as an implement of service. In the terminal room men stand in line before frames of myriad wires, the connections broken by tiny insulators. Mid- night comes. A handkerchief is waved. The insulators are ripped from the frames. In a second the new switchboard be- comes a thing alive. Without their knowledge thousands of subscribers are transferred from the old switchboard to the new. Even a chance conversation begun through the old board is continued without interruption through the new. The new ex- change provides for further growth. This cut-over of a switchboard is but one example, one of many engineering achievements that have made possible a wider and prompter use of the telephone. To-day, in maintaining a national telephone service, the American Telephone and Telegraph Company, through its engineering and research departments, continuously makes avail- able for its Associated Companies improvements in apparatus and in methods of operation. 7 GF 8. AMERICAN TELEPHONE AND TELEGRAPH COMPANY AND ASSOCIATED COMPANIES BELL SYSTEM One Policy, One System, Universal Service The Switchboard Comes to Life bLI TLR SEOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY FINISH off a day of unaccustomed man- ual work with an appli- cation of Absorbine, Jr. and you will aot experience threatened second-day stiffness. All druggists’, $1.25 or postpaid. Liberal trial bottle roc. postpaid. NG ciency of sets costing three times as much. over 1,500 miles away under good conditions, Tired feet Sore muscles After shaving Strains Bruises or 808 Main Street At the low prices shown below you get the effi- These radio frequency receivers pick up stations W. F. YOU . INC. Operate either on DRY CELLS or storage battery 350 Lyman St. Springfield,Mass. Cathet of solid mahogany and wurkskanstiip the finest throughout. Order direct or send for bulletin. Two tube outfit, as shown above, headphones only $29.50. Four tube outfit for loudspeaker or head- xyhones $54.50. © EALERS AGENTS ~Write for proposition quickly—it's a winner THE MIDWEST RADIO COMPANY Cincinnati, Ohio who | have much com- mutator work to ea N. CoAKLEY, Buffalo, N. Y- Thin Wrench Speeds Work ie Replacing Ford Universal HEN the rear axle assembly of q' Ford passenger car or truck is re. moved for repair, the replacement of the universal is a time-consuming operation. The square end of the universal must he held true and in exact alinement with the corresponding hole in the transmission. By the use of a slender-jawed wrench, approximately 10 in. long, the work js UNIVERSAL JOINT The wrench, made from sheet steel, and how it is used to replace universal simplified greatly. After the universal has been entered into the casing, this thin jaw wrench is operated through 7% eo a narrow slit to set and turn the universal until the required alinement has been ob- tained. This maneuver cuts down the time to only a few minutes. Sheet iron or steel, which can be sheared out, is used in making the wrench. Boiling Hammers in Oil to Make the Handles Last NE of the old hands in our tool shop * was annoyed recently when the head &F of the hammer he was using flew off. The tool belonged to an apprentice, so he took the time to replace the head himself, after sandpapering the end to a perfect fit. He | : drove the wedges in the usual H form, | sandpapered the end, and put the ham- mer in a can of linseed oil. This was placed on top of the shop salamander and the hammer was boiled slowly for three | hours. ‘My own hammers were treated in this way 10 years ago,” he told the appren- tice, “‘and the handles are still tight and | good for 10 years more.” —F. N. C. . Cutting Commutator Mica with a Homemade Tool LECTRICAL workers do will find this St mica-cutting tool My) — a time saver. The Ao handle, which is HACKSAW BLADE made from hard wood or fiber, is slotted to take a short | length of hacksaw blade. The blade is | held by two bolts, which pass through | angular slots in the handle and vertical slots in the saw. The slots allow the blade to be set at an angle when the work so requires. i ee | Eee gpraee,

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c of il r of a! is re of the ration, ust be ith the sion. Trench, rork is and rsal riversal g, this through § niversal § een ob- F time to or steel, used in il to st 901 shop he head ff. The he took lf, after | # fit. He | & H form, | ne ham- | his was der and or three | d in this appren- ght and | C. | a with a AW BLADE a short blade is through | vertical ye set at quires.— SE Scrap Parts Used for Ingenious Rod-Bending Fixture HILE on construction work at a large Australian electric power station recently, I had to connect seven large oil switches with 1-in. copper rods having double cones and nuts at each end. It was absolutely necessary to bend them to come correctly to their places within 1/32 in. The company could not supply a bending machine, so I made the fixture Construction of the bending ma- chine and the type of work done with it illustrated from material picked up from the scrap heap. I filed the thread almost out of two 1144-in. nuts and sawed each one in half. From a piece of %-in. lead cable sheathing I made two bushings, cut them in two lengthways and placed themsoasto project Yin. beyond the nuts. A 6 by 4 by 14 in. mild steel plate was used to hold the nuts down on a 6 by 6 by 3 in. I beam, 4 ft. long. The bending handle was a 3-ft. length of 1-in. pipe with a steel collar shrunk on the end, the sharp edge on the inside being filed away.—H. B. J. Lowe, Melbourne, Victoria, Australia. Combined Straight-Edge and Level for Large Work USEFUL tool used by one jobbing carpenter is a straight-edge about 8 ft. long with a recess for holding a builder’s 18-in. level. This saves the time of handling the usual plumb line, straight-edge, and level separately. The device, which is made according to the accompanying drawing, is used for An ordinary carpenter’s level is attached with clips and bolts to a straight-edge brick and concrete work, framing, cement floors, and all construction that requires the leveling or plumbing of a relatively large surface. The normal use of the level is not interfered with, and the Straight-edge also may be used inde- pendently.—G. A. L. BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY Sargent Planes Sargent Auto-Set Bench Plane Sargent Steel Block Plane make a quick, clean job of it WHATEVER it is—if it is made of wood and needs smoothing or finishing—one or the other of these two Sargent Planes insures satis- faction. For heavy work, or where good deep cuts are desirable, the Sargent Auto-Set Bench Plane fills the bill in every particular. At the same time it is an excellent smoothing and finishing tool—an all ’round plane for the busy workshop. Examine the Auto-Set at your hardware dealer’s. Note how quickly the cutter of chromium steel may be removed and replaced when it does need sharpening— all without disturbing the original adjustment. Back in place, not even the toughest or knottiest wood can make it chatter. For the smaller jobs, for cabinet- making, for getting into real close quarters, and for the finishing touches to your workmanship, you need the Sargent Steel Block Plane. This is made with the same care and precision which character- ize every tool bearing the name Sargent. These two Sargent Planes should be on your work-bench. Write for booklets. © SARGENT & COMPANY Manufacturers 50 Water Street New Haven, Conn. _ Jools ‘—\ ALL INSTRUMENTS AT yj MAKES BAN Vsto¥2 PRICE! 5 All famous American and imported instrum bend, “paws or solo offered at oqentnmaty. low % bargains in new list. New Guar- Pintes.6 Daye Free Trial and money back guaranteed. ‘J antee. d Buescher and all other ‘amous mak ents for CONN Buescher, Boston, Silver plated ‘old bell Cornet, in case, pearl eys. Slightly used, complete- ly xebullt, acetone new con- ition, perfect. list. Our price.... $17.95 es in re- built, new condition ffered | , reeds, strap, pearl keys, completely rebuilt and replated—get our bargain liet for descriptions Drices as low as 7s ~ Saxophones o' with case by most f. f ney 4 U.S. amo! a Ls] ° Low pitch, pearl keys. List $35. 2.2. 2 latest bargain list teday! Wabash Ave., Chicazo Agents Wanted! Salesmen~Distributors to use and introduce attachment that makes Fords run on 94% air. THERMOSTAT on ex- haust automatically turns down needle valve as engine warms, exactly as ‘ord Manual says do by hand. \ Biancke Auto Thermo An Automatic Carburetor Control Makes Fords start easier winter or summ: ves half gas and o:l—cuts repair bills one-half—reduces carbon formation one-half. Sells on sight to every Ford owner as easily as giving 4% bim a $100 bill, because it saves $100 every 10.000 miles. Cadifac now uses as standard mt thermostatic or control under Bilancke license. You can make Big Money selling 7 Se opie tt yt ee ee capital in t Shakes you from $250 to $2,000 a month profit. tn eee One ree Write for free circulars Now! A.C. Blancke & Co. £22,"2"sSte** Dept.120, Chicago

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A good plier is one of the most useful tools you have in your home work- shop. Whether you are building a radio or simply have to “fix the bell’’—you can depend on your sturdy Klein Pliers. Your hardware deal- er will tell you they have been the qual- ity plier for sixty- seven years. © Klein’s ‘‘Pocket Tool Guide’’ is a little book that will help you select vour pliers. Drop usacardfcrit. It’s free. 3220 Belmont Avenue Chicago, Illinois coon BG LEE o Sees Chicas {LSA BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY Secrets of Cutting Threads (Continued from page 76) back by hand. This is much faster than waiting for the carriage to reverse with the nut on the screw. Expert hands can do this without stopping the lathe. This is accomplished by backing the tool out quickly at the end of the cut and running the carriage back to the chalk mark on the way, the spindle running all the while. With the right hand on the nut lever, watch for the chalk mark on the faceplate to come around to the front way and throw in the nut. The tool, of course, is set in for another cut and run in to the stop. This requires alertness on the part of the opérator, but with a little practice it is not hard. te ALL modern lathes provided with a dial indicator for cutting threads, the chalk marks are unnecessary; this is used only on old style lathes. The com- pound rest is set at 30 degrees, or half the angle of the thread, and the point of the tool approaches the work each time it is fed in without altering the true angle or lead of the thread. This allows the tool to cut on one side only and prevents a burr. There are, of course, some cases where it is impossible to set the compound at this angle, in which case the thread will have to be cut with the tool at a right angle to the work. Threaded parts always should be fitted to each other for accurate work. Cut the screw down nearly to size, measuring with thread calipers, and then finish the thread by trial with the nut or correspond- ing part. When the correct size is nearly reached, clean and oil the thread after each cut. The diameter of threaded work is measured, of course, from the top of the threads and represents either the greatest | diameter of the screw or the greatest diameter of the threaded hole. The root diameter is measured at the bottom of the thread. One of the handiest devices for setting thread tools is the gage shown at the top of Fig. 2, page 78. It is used, as shown in Figs. 2 and 3, to set a threading tool level with the center of the work and square at the same time. The method of setting a tool for a 29- degree thread with an Acme Standard gage is Fig. 4; and in Fig. 5 is illustrated the use of a center gage in setting a | thread for cutting an internal United | States standard or V thread. F THE work is cast iron, the thread should be cut dry; if steel or wrought iron, lard oil should be used. Use oil on all work when fitting it to a mating part, so that there will be no chance of the pieces seizing in such a way as to make it difficult or impossible to separate without damage to one or the other. | Half the battle in thread cutting ‘is to | be sure the set-up is right. Try out the tool and thread on an extra piece, if pos- sible. This takes time, but it is better to be sure than to have to explain a “bull” to the foreman. | All good machine tool work depends | on one thing: Be sure you are right be- | fore going ahead. If in doubt, don’t take | (Continued on page 89) | ‘WOLF TONES”’: Good-bye “forcing,” ‘“‘favoring,” ‘‘faking.”” Gone the days when even the fircst musicians played in constant dread of the imperfections of their instruments! The century’s most revo- lutionary improvement—a continuous conical bore—makes brass instrument playing simple and easy. In 30 days you may be playing in a band! Continuous Conical Bore Couturier Band Instruments alone follow Nature’s law that “asound wave ex- pands diametrically asit travels.’’ The result—easy to blow—tones true to pitch in every key and in- terval—full, round, velvety tones right from the be- ginning! Write today for FREE Catalog describing these easy-to-learn instruments. Convenient payments can be arranged. Pay as you play, from your earr- ings, as thousands have done. (Mention whether you want Band Instruments or Saxophones and if you now have aninstrument). Write Today! EYONG HEALY P.M henge CHICAGO DEALERS —Some choice territory still available Catalog FREE! Send for the MONARCH Lathe Catalog— fully illustrated—every type Lathe up to 30 inches swing. Illustrated here is the MON- ARCH Jr. Lathe—an accurate, compact, trouble proof Lathe for Inventors, Experimenters. Me- chanics and Auto Repairmen, Fully equipped— semi -quick change gear —auto- safety de- vices. $270 1S] 9"' lathe— 214 ft. bed with bench legs Also built with bed lengths up to 5 feet. Made in 11 inch swing size too, at slightly higher price, The Monarch Machine Tool Co, 401 Oak Street SIDNEY, Ohio Change Blades Instantly N this Simore Combination Knife and Screw- driver, there are three blades in the handle. Each blade snaps back into the handle after it has done its duty just as is shown here. And 4 you select and produce the blade you want /é/ by gravity just as easily and quickly. You y actually change blades instantly with this tool. Model No. 12, with knife blade and two screwdriver blades. Only $2.25. Model No. 11, with three screw- driver blades. Only $1.80. Sent postpaid on receipt of money or- der or your check. Satisfaction guaranteed. Ask your dealer or © write direct. Dealers are invited to write for infor- mation on Simore tools. The Simon & Skidmore Mfg. Co. Dept. 5-7 Santa Ana, Calif. REE € & bs # Design, Workmanship, and finish of the highest order are found in all Gerstner Tool Cases for Toolmakers and Machinists @ They please. Write for free catalog. H. GERSTNER & SONS 507 Columbia St.,Dayten, 0. _— ;ac | rig! i x ati | of | Th on cen pla kee B | thr | the “m ia. whi Use | squ | cen | allo S| tho & Ps | the & i | wal car Pla oil. cro: by adji feec line Ss of t Thi 1M carr stor Nov corr cut, ofa Rev | run | witl ' tool i | i lof finis or le that may turn fore i | loos [may } that A an € spr load Le gear with mus‘ In a gry the « gro9 full ( On t bein Ss! — ing Scra “Ma and Sha

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ex- in- be- ese nts m= i if vd. oO able on [(ON- yuble Me- ed— quick > gear | de- anship, highest in all Cases lachinists Jrite for & SONS ayton, O. ne —_—_— ' | right. Secrets of Cutting Threads (Continued from page 88) a chance and hope things will come out all In threading, go slow and be sure. Generally speaking, for threading oper- ations, place the belt on the largest pulley of the lathe cone, if a belt-driven lathe. Then screw on the faceplate, fasten a dog | pn the work, and place the work between centers. Chalk mark the slot in the face- plate where the dog engages it. Always | keep the dog in the chalk-marked slot | throughout the work. Turn the work to j i the screw diameter, measuring with ‘mikes.”” Have the finish smooth. Next set the thread tool, the form of which depends upon the thread to be cut. Use a gage to make sure the tool is square with the work and even with the center. Adjust the thread stop that allows the cross feed to be adjusted in thousandths. Set the gears for the thread |, wanted and be sure the friction feed of the carriage is out before engaging the nut. Place a tin box under the tool to catch the oil. Adjust the micrometer stop on the cross feed so that the tool clears the work by about .001 in. Start the lathe and adjust the micrometer stop on the cross- feed so that the tool traces a very light line on the work. Stop the lathe before the tool reaches the end of the thread and finish the length of the thread by pulling the belt by hand. This is necessary the first time only. N OVE the tool out from the work, run 1 the carriage back by reversing the carriage feed and adjust the micrometer stop to make another cut of .003 in. more. Now check your threads. If they are correct, start the lathe and take another cut, pulling out the tool about one-third of arevolution from the end of the thread. Reverse the carriage, and while the tool is running back, lubricate the work freely with a brush dipped in the pan under the tool. Keep the work clean and take cuts of .005 in. when roughing down. For finishing, the cuts should be about .001 in. or less. Keep trying for size and remember that after the thread is smoothed down it may be too loose. If the screw can be turned into its mating part by hand be- fore the burrs are removed, it will be too loose after they are removed. The threads may be lapped by means of a split nut that has the same thread. A gooseneck thread tool (Fig. 6) makes an especially smooth thread, as the tool springs down from the work when over- loaded. Left-hand threads are cut by fixing the gears as in cutting a right-hand thread, with the exception that the lead screw must rotate in the opposite direction. In cutting inside threads to a shoulder, or must be made inside the work at the end of the thread. as in Fig. 1. This groove must be a little deeper than the full diameter of the threads. on the thread tool as a guide, the tool being set into the work at the groove. HOP features scheduled for early Place a line | publication are ‘Methods for Locat- | ing Holes in Jigs and Dies,” ‘How to | Scrape Metal Surfaces Accurately,’ ‘Making the Most of a Drill Press,’ and ‘Shortcuts in the Use of the Shaper and Planer,”’ BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY 1 Here’s an armhole that can't curl or rip— large roomy and tion-free. fri C- ? 2 es * Talk about comfort! WN The Hanes closed A crotch stays ft closed. It’s cut and stitched in a special way to insure com- fort. 3 Ke A wide, full-le ngth knee that won’t creep up your ail f won't bind! o There’s double strength, double elas- ticity in the Hanes webbing belt. It’s 2- thread instead of single. Sewed espe- cially to prevent rips and tears. ’ ™ 2, Tkis button re- fuses to come off. It’s sewed to the seam. Four thick- nesses of material instead of the usual two. No ; patch! bt a Say “HANES” and you’ve said it all ANES” is the word! You could talk for an hour tell- ing your dealer what you want in summer underwear and not say half as much as you will by simply saying ‘‘Hanes.” When you come out with “Hanes Athletics, please,” here’s what you really ask for: Under- wear that will fit and feel as if it was made for you, with all the freedom, roomy comfort and cool- ness that you must have for sum- mer weather. You ask for under- wear that is guaranteed right down to the last stitch and but- ton. Say Hanes and you'll get the best underwear value that ever came out of a factory—un- beatable quality at an unbeatable price—One Dollar. Go in to your dealer’s to-day and say “Hanes.” Make any comparison you like for work- manship and material. Compare the service and wear! If your Full IC ut ATHLETIC UNION SUITS regular dealer can’t fit you, write us at once. Hanes is made for boys, too, in the same quality. ‘They are from 2 to 16 years—sizes 20 to 34. Read this Guarantce: We guarantee Hanes Underwear absolutely—every thread, stitch and button. We guarantee to return your money or give you a new garment if any seam breaks. P. H. HANES KNITTING CO. Winston-Salem, N. C. New York Office, 366 Broadway Nort Winter Wear Manes Winter. Uruderurear Tool Cases for Machinists, Car- penters and Tool Makers; none better; thirty styles. Quarter- ed oak and metal cov- ered. Ask for booklet. ‘“‘Built for Service’’ The Pill Pilliod Lumber Co., Swanton. Ohio =) $4.00 Adding Machine The Gilson Adder will do your figuring A easily, quickly and with absolute ac- curacy. Capacity 109,999,999 to +} $1,099,999.99. It adds, subtracts, multiplies and divides and automatically ‘| carries from one column to the next. Made with aluminum case and _ steel operating parts size 31 gUXO"XIA", 4 Written Two-Year Guarantee. Catalogue Free. Price, postpaid, $4.00, Your money back if you are not satisfied. J Gilson Slide Rule Co.. Niles, Mich. SCREW C ITS THE POINT. Imported from Japan. quantity price list and distributing plans. F. SP Sells for $1.25. Agent’ s Sample 65c.! ABSOLUTELY. FRICTION-TICHT. PREVENTING WISTI - PREVENTING TW! NOH-LEAKABLE\ pittance HAS EIGHT GROOVES. FOR INK TO FEED **It makes Carbon Copies.’? Guaranteed for 1 year. Mone -y refunded if you don’t think it’s the best p> 2 Ry Sure wrote with. Sa: :CO.. New Self-Filling Bamboo Fountain Pen with Stylo Point Hustlers Making $20 Deliy! Up to 150 per cent Profit. Send for 199 S. 4th St., Lesueur Center, Minnesota

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90 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY “The Williams Cap is in the ring— IVOTE FORITY" HE big vote is going to Williams and the reason is clear. It has the one shaving cream cap that can’t get lost. And Williams offers you three definite improvements in shaving: —There’s that famous Williams lather: its closer texture holds the moisture in against the beard. Quicker softening results. —There’s a lubric quality in Williams lather—actually a film between razor’s edge and your skin. Pulling and irritating friction are eliminated. —There’s a soothing ingredient which leaves your face smooth and flexible even in hurried daily shaving. Of course, you'll like Williams! It is made by shaving soap speci- alists—a pure, natural-white cream without coloring matter. And the tube has the new Hinge-Cap! Tue J. B. Wittiams Co., GrastonsBury, Conn, The J. B. Williams Co., (Canada) Ltd. St. Patrick St., Montreal Williams Shaving Cream with the Hinge-Cap that can’t get lost — We’ve scored | again! AquaVelva is the new prod- uct —a_ scientific formula for use after shaving. For free trial bottle, write Dept. 107 Wooden “Ponies” ATER polo is By Roland B. Cutler keen and hilari- t ous sport for the rider of one of 2 by 2 by 19 in. and center the bolt hole these skittish ponies. To jog the “ani- mal” about the ‘“‘field’”’ and dribble the ball over a goal, requires skill that makes a real game, although the apparatus is homemade and inexpensive. And any playing arguments can be settled by a tilting contest—a regular medieval joust, most amusing to onlookers. All this aquatic fun is perfectly safe, for a discarded auto tire buoys up each pony. A 10-in. piece cut from the end of a mo- lasses barrel is suitable for a flivver tire. One hoop clinches the tire above its rim. Below deck, two joggers work inde- pendently, each hung between 2 by 3 in. ribs and an outside cleat. Center one rib across directly under the barrel head and fasten another to the stave ends below. A jogger is formed with 12 in. of a two- by-six, and a 12-in. board arm attached with two corner braces set into the plank. At the other end of the plank, trim off a 3-in. corner and bore bolt holes 5 in. apart and 1 in. from the edges. A sheet-steel oar is riveted to two 6-in. strap hinges under the board. Fasten each strap with three screws, and bend about Construction of the aquatic horses. of the two foot-driven oars is omitted from upper view 214 in. of the end at right angles to serve asastop. When propelling, a chain holds the oar at right angles to the board. Above deck draw a center line (shown dotted) at right angles to the rib. At one side of this line and directly over the rib, bore a 2-in. post-hole. To the rear, 3 in. from the center, pivot the joggers to the rib with an 8-in. bolt. Cut a seat-post 36 in. long, with. a 10-in. end to extend below, preferably into the lower rib. A two-board | truss, 6 in. high, supports the post and | allows it to be adjusted for height and balance. Set a corner. brace at each side. The truss is braced at the rear by a two- piece crupper, 14in. long. Let the base be 3 in. wide, set into the truss, and nailed over the barrel rim. Cut a treadle 3 in. wide, to extend about 4 in. beyond the deck when hinged to the edge of the crupper with a 3-in. butt. Each piston or plunger opening is 4 by 2 in., located 1 in. from the cross line and For clearness, one ——_—____ for Water Games 314 in. from the rib cep. er. Make each piston 1 in. from one end. The saddle is formed by a pommel 3 by 14 in. long, a cantle 7 by 13 in., and a7 by 11 in. seat. Padding may be old inne tubes covered with canvas. Connect the treadle springs with the post for quick action. Foot cleats should be used | on each treadle. The materials needed are: 1 board, % by 7 in. by 2 ft. long 1 board, % by 6in. by 12 ft. long 1 two-by-three, 6ft.long 1two-by-six, 3 ft. long 4 strap hinges, 6-in. 4-ft. jack chain, 1-in. link, 2 butt hinges, 3-in. 2 door springs, 4 by 16in, 2 butt hinges, 2-in. 1 bolt, 5/16 by 8 in. 6 corner braces, 4-in. 3 bolts, 4 by 4% in, Using the water “‘ponies”’ for jousting 4 pes. galvanized sheet stecl, 6 by| 10 in. automobile tire and tube, dix carded stock 4 doz. screws, No. 8, 34-in.; 1 doz] screweyes, 114-in.; 34-in. rivets] washers; 10d. nails. _ A mallet is made with al 5-in. length of flivver tire, a] 2 by 3 by 3 in. block, anda] handle 3!4 ft. long. Shapeaj ball 4 or 5 in. in diameter from some light wood or use a 6-in. water ball if there are several players. For tilting, use a light pole about 9 ft. long, to one end of which is wired a 16-in. door spring, as indicated, for holding the padding of cot ton waste. The game may be at justed to polo rules, or sim ply “‘nip and tuck” to goal the ball. 4 tilting contest consists of equestrian maneuvers and “‘hit-or-miss’” jabs until somebody gets a: ducking. Coming Workshop Features “DM UVILDING Radio Home,” by Swezey. “Making a Six-Inch Jointer for the Home Workshop,” by Frank N. Coakley. ‘How to Construct Airplane Kites,” by Charles M. Miller, leading author- ity on kite flying. ““A Grub Box for the Canoeist,”’ by Leroy W. Hutchins. “Saving your Engine Bearings,” by Ray F. Kuns, author of ““Automotive Trade Training,” and one of the fore- most experts in his field. into Your Kenneth M. the yea and sum usef Arb seat prir seats tion. lof B the « Ot mer the ]

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ey | es cen- iston hole 3 by .T by inner nnect t for used | ong n. link, y 16in, ne In, | tecl, 6 byt } cube, dis n.; 1 doz in. rivets: ] » with al or tire, a k, anda| Shapea| liameter yd or use if there s. Fotl sle about} . end df -in. door ted, for g of cot - be ate 3, Or silk ball. A questriat abs until tures Your th M. for the nk Kites,” author- ist,” by gs,” by pmotive he fore- eae year. Profitable Outdoor Work for the Amateur Mechanic OODWORK that can be done out- doors has special attractions for Arbor with gate and seats built from Blue- | print No. 9 in the Home Workshop Series the amateur mechanic at this time of the It is a real pleasure to take toolkit and sawhorses outside in the long, light summer evenings and build something useful and ornamental for the house, porch,or garden. Clear, ac- curate and au- thoritative working draw- ings for sum- mer projects of clean cut design and un- usual utility are contained in POPULAR SCIENCE MONTHLY’S series of blue- prints. One is the arbor with gate and two seats shown in the accompanying illustra- tion. This was built by Orbrey K. Miller, | of Bellevue Park, Richmond, Va., from the details in Blueprint No. 9. Other good blueprints for the sum- | mer are Nos. 10, 11, 23, 25 and 34, in the list below. EE 32. Chinese Game Table. . 33. Pullman Dining Alcove 2 34. Trellises for House and Garden. .25c Complete List of Blueprints | gd one of the blueprints listed below can be obtained from POPULAR SCIENCE MONTHLY for 25 cents. The Editor will be glad to pro- vide, upon request, information rela- tive to tools, material, or equipment. Blueprint Service Dept. Popular Science Monthly 225 West 39th St., New York. GENTLEMEN: Send methe blueprint, or blueprints, I have underlined below, for which S| eee cents: No. Title Price Te Sewing Tale... a 5.5 60's esse vce ess 25c 2. smoking Cabinet. ........5...0... 25c 3. Book Trough End Table........ 25c >. Kitchen Cabinet... . 66 s+ 0s 2oc 6. Two-Stage Radio Receiving Set. .25c 8. Shaving GCabmet............-%. 25¢ 9. Arbor with Gate and Seats...... 25c MOS AGUGI SEMIN ooo aye sara a owe. 6078 5c 11. Bench and Tilt-Top Table...... 25c 12. Electric Washing Machine...... 25c Re OT ea re 25¢ 14. Toy Train, Horse, and House... .25c 15. Home Workshop Bench......... 5c 16. Inlaid Radio Cabinet........... 25c 17. Cedar and Mahogany Chest..... Zac 18. Telephone Table and Stool...... 25c¢ 19. Grandfather's Clock... ......:.. 25c 20. SAC LOR DOSE... .55.00ccwscscens 25¢ 21. Colonial Writing Desk.......... 25c 22. Girl’s Cabinet and Desk........ 25c 23. Pergola Garage....... 24. Gateleg Table........ 25. Sailing OutSt for Canoe 26. Baby’s Crib and Play Pen....... 25¢ 27. Kitchen Cabinet Work Table... .25c 2 28. Pullman Play Table............ 2c 29. Toy Tea Cart, Garage, etc...... 25¢ 30. Tool Cabinet, Bench Hook, etc.. .25c 31. Priscilla Sewing Cabinets....... 25¢ HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Will. Fit all the Nuts an open-end wrench. to other wrenches. Cedar Street CHROME-VANADIU hness ~ VANADIUM for strength CHROMIUM for tou BONNEY ‘C.V. WRENCHES This set of six Bonney C. V. Wrenches will fit all the nuts on your car that can be turned with Because they are made of chrome-vanadium—the steel with four times the strength of ordinary steel— Bonney C. V. Wrenches are light in weight and yet so finely tempered that the jaws won’t spread or break. These six handsome wrenches weigh 20% less than six of the same size carbon steel wrenches. Their thin, finely tapered jaws make it possible to get at nuts inaccessible Write for our catalogue or, better still, send $5.00 and we will send you this fine set of wrenches. if you want a sturdy leatherette case. Sold by Auto Accessory Stores and Good Hardware Stores BonNnEY Force & Toot Works The ‘*C.V.’’ Trade Mark is reyistered in U. S. Patent Office. Allentown, Pa. Add 85c If you do not feel that they are the finest set of wrenches you have ever owned, we guarantce to refund your money promptly. Oar deal- ers make the same guarantee. Parks ‘‘Cabinet Shop Special’’ $225.00 complete with motor f.0. b. Cincinnati. Send for Bulletin - S describing this machine in detail wa Z Ever Built! saw, 4-inch jointer, band-saw, Complete with lathe attachment struction, all joints electric-welded. equipment. Guaranteed 10 years. als. a2 a8 WOODWORKING The Biggest Little Woodworker You'll want this sensational Parks com- bination woodworker right away for your shop—includes 8-inch rip and cross-cut shaper, sander, and universal motor. $225.00. First-class Parks angle-steel con- table-top. The newest thing in small shop The Parks Ball Bearing Machine Company 1547 Knowlton St., Cincinnati, Q. Canadian Factory: 200 Notre Dame East, Montreal, Can. For every man who buys or uses saws there’s an Atkins saw to do the work easier, quicker and better. Here are three of many popular Atkins saws your hardware dealer can show you. SHIP POINT Finest saw made—in quality, workmanship finish. Genuine SILVER STEEL BLADE, and Ship point, 26-inch length, five gauges, taper ground. MIRROR POLISH. Solid ROSE- WOOD HANDLE. Improved Perfection Pat- tern. Skew or Straight Back. JUNIOR MECHANIC HAND SAW __2 A new saw for the Boy Scout and radio or junior mechanic. Handy for home use, too. Made 20 in. long, skew back, nine points, taper ground, highly polished; cherry handle, mission stained. Nol ps , Hard rubber, “easy grip” pattern; hung low, thus directing full stroke to cutting edge. Steel frame is nickled, highly polished; adjustable to 8, 9, 10, 11 and 12-inch blades. Equipped with an Atkins Non-Breakable Blade. “‘Saw Sense” shows Atkins wood- Booklets cutting saws. ‘‘Saws inthe Shop” shows metal-cutting saws. Write Sent FREE for booklet you want. is) E.C.ATKINS & CO., Inc., Dept.D-20 Indianapolis, Ind.

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92 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE \iONTHLY MECHANICS’ HANDBOOK ERS MECHANICS HANDBOOK 330 PACES More than 300,000 sold oe book of its Only kind ever written. DPre- pared by experts under the direction of the Interna- tional Correspondence Schools. Written in lan- guage that you can under- stand. Note this partial list of subjects: $ Weights and Measures; Easily Under- stood Mathematics; Formulae; Mensura- tion; Belting; Hydro-mechanics; Strength of Materials; Boiler Design; Care and In- spection of Boilers; Horsepower of Boil- ers; Chimneys; Exhaust Heating; Machine Design; Horsepower of Engines; Boilers and Pumps; The Slide Valve; Belt Pul- leys; Rope Belting; Cylinders and Steam Chests; Electricity; Currents; Wiring; Dynamos and Meters; Batteries; Cable Testing; Compass Surveying; Curves; Leveling; Etc. Just mail this advertisement with a dollar bill and your name and address, and this 330-page I. C. S. Mechanics’ Handbook or any of the other I. C. S. Handbooks that you want will come to you by return mail. carn nr nr nnn nr ne eos | INTERNATIONAL CORRESPONDENCE | SCHOOLS | Box 7697-C, Scranton, Penna, | | I enclose $ for which send me, postpaid, | the Handbooks marked X, at $1.00 each. It is | understood that if I am _ not entirely satisfied I | may return any or all of them within five days | and get my money back. | | 0 MECHANICS’ HWANDRBOOK | (jAutomobile Handbook ORadio Handbook | [Electrical Handbook CSalesman’s Handbook | (JChemistry Handbook Lj Advertising Handbook | CJBuilding Trades HandbookL)Bookkeeper’s Handbook | Easy toDraw Cartoons When Shown in the RIGHT WAY ome of and comic artists learned how to draw in their spare time by following Cartoonist Evans’ Simple and Easy to Learn Method an of the cleverest cartoonists r nd are now MAKING GOOD MONEY. Send one of your drawings, and let Mr. Evans see if you have ability and receive the Portfolio of Cartoons and full details yout the course. It is not expensive. THE W. L. EVANS SCHOOL OF CARTOONING 825 Leader Building Cleveland, Ohie Trick Water Swing Furnishes Hilarious Summer Sport By Dale R. Van Horn T ANY summer camp this trick water swing will afford lots of fun and excitement. Select a tree limb over- hanging the water and to it fasten two pulley blocks. Run the rope over them and bring the ends down to within reach of the seat, which should hang about 1 ft. under water, as indicated. Either splice the ends to the main rope or bind them tightly with cord so that they cannot pull loose. The bather stands on the swing seat and by pulling the rope ends, raises him- self out of the water. When the seat is At full speed, the swimmer swings through the water in showers of spray clear, he holds his arms in the slack to keep the swing at this length, and begins to swing. Faster and faster he goes until finally, at the highest point of one of the swings—at the point of rest—he lets out the slack. With a great splash, the swing strikes the water and passes through it, throwing up a heavy spray. The best way to take the water dive is sitting down, which can be accomplished by the bather’s sliding his hands down the rope and dropping to the seat, feet fore- | most. If the slack is released at the mo- ment of rest at one end of a swing, there is no danger. Improving an Icebox ‘TBE swinging door at the bottom of many types of iceboxes often has no | catch for holding it up while the water- pan is being removed for emptying. In such cases it is an improvement to fasten | ] | PROP WATER PAN Hinged prop drops down and supports swing- ing door while water-pan is being emptied a thin strip of wood loosely with a nail or screw to the bottom, as indicated, so that it will fall down when the door is lifted and act as a prop to hold the cover open when removing pan.—E. B. HILL. ef ace genuine UNDERWOOD Yes, only $3 down puts this genuine standard Shipman -Ward Rebuilt Under- = wood in your home. Then—small monthly payments, or if ee cash. Either way you get the world’s standard typewriter at a big cash saving. WHY PAY RENTAL? The only difference is that Pp ar hii are priced lower and are rebuilt like new by experts. You can’t tell them from brand new machines. Visible writing —the FULL LINE of typewriting is visible at all be times. STANDARD 4-ROW SINGLE SHIFT KEY- (2 BOARD. Two color ribbon, back spacer, stencil de- fs vice, automatic ribbon reverse, tabulator, etc. TEN DAYS’ FREE TRIAL Be See for yourself! Try the typewriter ten @ days. You must be satisfied or the entire trans- i action won’t cost you cg dt Act today. Get ea our eo catalog and full particulars. & Write NOW. --~=FREE TRIAL COUPONe==- ', Typewriter Emporium 4 SHIPMAN-WARD MFG.CO, B214 Shipman Bldg., CHICAGO £ Send by return mail Bargain Offer No. B 214 l 4 of a Standard Visible Writing Underwood. | This is not an order and does not obligate j me to buy. Why Old Age Pains? Don’t put up longer with aches in back and feet, sciatica, rising many times every night, or prostate gland disorders. An amazing discovery by | a Member of the American Associa- | tion for Advancement of Science has already been used with astounding | success by over 10,000 men in allevi- ating these and similar disorders. | Write for Free Book Prostate disorder comes to nearly two | thirds of men past middle age according to highest Medical Authorities. Find out now how you can avoid, and relieve | these distressing conditions—without medicines, lessons, violet rays, electricity | or diets. Write at once for interesting | Free Book ‘‘Why Many Men “Are Old | | at 40.”’ Address: | | } | | | THE ELECTRO THERMAL COMPANY, | Ohio | ie 4035 Main Street, Stubenville, Print Your Own Stationery \avperccsnt —~. tars, menus. circulars, cards.ete ==)Press $12, Larger $35, Job Pres $150 up. Easy to operate by of printed rules with every press MAKE MONEY ! Print for other? inspare time. Write today fot : catalogue, presses, type, ©# Ae s. The EXCELSIOR envelopes, paper. supplies PRESS CO., D-33 Meriden, & — — 1 COR OT 8 ae TTT Ty TS PO

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two rding | Find | lieve shout | ricity | sting | » Old | | ANY, Ohio —— head, em ne, receipt, 3, cards.ete , Job Pres rate by of very press t for others > today for ype, cards plies. jeriden, Ce HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY By Frank W. Harth \ HILE a tennis court usually is con- | and exercise, there is no reason why it | sidered only a place for amusement | cannot be as ornamental and pleasing to | inclosure the eyes as any other piece of landscape architecture. As a rule, a tennis court is laid out in some corner of the yard or | garden with | nothing sur- | rounding it but | grass or per- haps an_ ugly inclosure of poultry netting. The beautiful = and ornamental LATTICES” illus- POST:.- on AKIO oO a Ie eee ae ti es Se * S223 x} Sees eae Entrance to the inclosure, with rustic benches. A detail of the woodwork is shown above trated may be constructed easily of ma- terial that can be obtained from almost any lumber dealer. The corner posts can be three by threes or four by fours set into cement, or held in place by stones with the earth firmly tamped around them. The construction of the archways, at first thought, may seem a difficult problem. The method is to bend thin strips to shape, using enough strips to form a square cross section. The lattice work can be made of ordi- nary shingle lath fastened to the frame- work, which is made up of common fur- ring strips nailed to the posts as shown in the detail. Several coats of good outside | White paint finish the job. Scratchless Fly Swatter ‘LY swatters made from old inner tubes never scratch the furniture as broken wire ores sometimes do. of the tube to a flat stick with tacks driven through pasteboard washers and slit the rubber up in a number of places with the scissors.—S. R. R. The New All-American Long Wave Radio Fre- guency Transformers $6 eras warokmee & > RANGE 4000-10006 MZ TYPE R-170 Of RAULAND Mec. Co, OES Hig CHRO The MASTERPIECE For Super Heterodyne, Ultradyne and all straight radio frequency and reflex circuits, every conceivable test reveals this new All-American Trans- former to be “the Masterpiece cf Amplification.” It is for wave lengths 4,000 to 20,000 meters. AMPLIFYING TRANSFORMERS © Another All-American triumph that will further broadcast our good name already so splendidly upheld by nearly three-quarter million All-American Audio Frequency and Power Amplifying Transformers now in service. SPECIAL OFFER! Diagram-circular on power am- plification and All-American Book of 22 Tested Hook-ups sent for dc in stamps. Address Rauland Mfg. Co., 2667 Coyne Street, Chicago. RICAN Largest Selling Transformers in the World Have You AN INVENTION? If so the WORLD PROGRESS will show you how to Protect and Profit From Your Ideas Sample copy free. One year’s subscription 40c. Send for free book, “WHAT TO INVENT” containing Suggestions to Inventors as to Inventions Needed. We invite manufacturers to address us regarding inventions they want. WORLD PROGRESS PUB. CO., INC. Room 202 Victor Bidg. Washington, D. C. i Made $100,000 in less than five years as a real estate specialist. Started during my spare time, with no ex- perience, and less than $5.00 capital. If you want to learn the secret of my success and follow money-making method, send your name and address at once to American Busi- ness Builders, Dept. A-347, 1133 Broadway, New York. They send full information free, telling you how you can build up an inde- pendent profitable business of your own by using my amazing successful system. Fasten a piece | LEARN BY DOING Every phase of all branches ELECTRICITY taught by Actual Practice In America’s foremost and oldest institution for trade training No Books Used Individual Instruction Start Any Day Write for FREE 64-page catalog THE NEW YORK ELECTRICAL SCHOOL 40 West 17th St., New York City Open All Summer | | | We Teach COMMERCIAL Pr A oe Meyer Both Company, the largest Commercial Art Organization in the Orld offers you an unusual opportunity for practical training, based upon twenty-three years of success. This nationally known organization each year produces and sells to advertisers over 15,000 commercial drawings. Meyer Both in- struction is the difference between successful fact and experimental theory This well paid profession equally open to men and women. Home study instruction. . Get Facts Before You Enroll in Any School Ask the Advertising Manager of the leading news- papers in your city, anywhere in the United Mm States, Canada, England or Australia about the Meyer Both Company—let them tell y youabout us. Write for our illustrated book telling about the success of our students—for one-half the cost of mailing—four cents in stamps. MEYER BOTH COMPANY Department of Art Instruction Michigan Ave. at 20th St., Dept. 35, CHICAGO, iLL. Note—To Art and Engraving Firms: Secure practi- cal artists among our graduates. Write us.

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94 Wear the i Micesine DSley b, H YERYWHERE you see it! Saturday afternoon or Sunday morning, the car run out in a shady spot, a Kit of Snap-ons on the running board and Dad or Brother Jim tuning ‘er up with a broad smile on his face. If the car’s a Buick, it’s a Buick Kit, and a Ford Kit if it’s a fliv. Exactly the right number of sockets and handles to tighten up every nut and bolt on the bus, hard to get at or easy, in half the time any other method could do it. You’d smile too, 1f you had a Snap-on Kit, specially selected for your car. Why not send for full in- formation today? A , Not handful : a “set” in a Kit but a to service SYSTEM your i for car indi- t speedand vidually saving t » Sap-on INTERCHANGEABLE Socket Wrenches MOTOR TOOL SPECIALTY 14 E. Jackson Blvd., CHICAGO Gentlemen: Please send me full particulars about Snap-on Kit Me ors cullen eee car. (If interested in Master Deechamiecs Est. check here... ccc ccc cscecsenesces ) I PURE ok vic Gone en ka ee aenonh samen aweens PR Ress iad hin ok RS i ge ale ihn eit HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Saving Your Auto Engine Bearings By Ray F. Kuns Author of ‘‘Automotive Trade Training’’ WO neighbors buy cars of thesame make on the same day. They drive them ap- proximately the same mileage the first season. At the end of the season each has paid about the same amount for main- tenance and repairs. However, one car is in prime condition; the other is about ready for a complete overhaul. “T have driven that car 38,000 miles,” an owner told a service man the other day. “T want you to take down the crankpan, clean it out, and put it back with new gas- kets. It has been using too much oil lately, and I am sure the gas- kets must be bad.”’ “Do you want the bearings taken up while you have the pan down?” he was asked. “T should say not!”’ he replied. “T am taking care of those bearings and would not have them touched for any- thing. I want to see how far they will go without being touched.” Manufacturers are perfectly safe in guaranteeing their engine bearings for 25,000 or 50,000 miles of service on con- dition that the proper care is given the lubrication. A properly designed bearing will just polish up nicely in a season, and after that there is no appreciable wear if the oil is right. I have just looked over two engines, one a 1913 and the other a 1923. Of the two, the 1923 model is far the older, with bear- ings scored and broken. The 1913 model has a fine polished brown glaze over the Babbitt surfaces and shaft journals and pins are like glass. Except for a minor trouble, the older car need not have been laid up now. The later model needs some new bearings and a complete overhaul. At right is an old bear- ing in perfect condi- tion because it has been oiled properly F THERE is clean oil in the bearings, the oil takes the wear. If the oil is dirty, thin, or worn out, the shaft cuts through it and rides on the surface of the babbitt, scoring it and wearing it out. When the time comes that engine bear- ings need care in the way of adjusting or scraping—taking up, as it is called—the oil pan or inspec- tion plate at the bottom of the crankcase is dropped. First, inspect all bearings to see if they show signs of burning. If they have been badly mistreated, babbitt will show in the oil trough in the crankease. If a decided knock has been indicated, learn which bearing is at fault. Second, inspect all bearing caps to see that they are marked in a manner to identify them. Usually, the rod bearings are marked 1-1, 2-2, 3-3, etc., on the cam- shaft side and running back from the front of the engine. Note the identifying marks on the main bearings as well. Third, proceed to remove the bearing BEARING > caps one at a time and adjust them. When a bearing cap is pulled off, make certain that the shims between the halves are kept in their proper position. Mixing shims will cause hours and sometimes days of hard work. Carefully remove the thinnest shim found on each side, or if the shims are of the patented type, pull or peel off a thin layer. Next, reassemble and draw the bolts quite tight. Use a socket wrench for this work. With the bolts tight, it should be possible to detect just a slight drag when the engine is At left is a relatively turned over with new bearing that has been burned badly because of inade- the hand crank. If too tight, in- sert thin shims. Filing bearing cap quate lubrication In some cases it is necessary to dress the shims down with a file to get the proper adjustment. In other cases it is necessaryto draw-file the caps. Extreme care is essential to suc- cess. It will not do to loosen the bolts a bit, as is the first impulse of the amateur. The bearing studs or bolts must be abso- lutely tight and the shims pinched hard. Add or remove shims, draw-file caps, and test and re-test until just an appreciable drag is noticed. That bearing is then finished. FRACK off the nuts a turn and adjust the other bearings, then go over the bolts and nuts and set them to the predeter- mined tight position, locking them with the cotter keys. If removable dippers are provided, see that they are assembled to dip properly. In some instances they can be assembled backward. Before replacing the crankcase, see that all oil tubes and oil holes are clean. Cleanliness and thoroughness of inspec- tion mean a great deal. Make certain new gaskets of the proper thickness are used when replacing the crankcase, else the oil dippers on the rods will give too little or too much oil. Make the job tight with shellac to insure economy of oiling. Drain oil every 500 to 800 miles and refill with good oil of the proper grade. Keep the crankcase gaskets tight, check the oil pressure gage constantly to see that the pump is working, keep the engine properly cooled, clean the crankcase each season by removing it, and satisfactory results will be assured. WHEN an auto is used much, the rear floor often becomes worn to such a degree as to be unsightly. The old carpet or rubber mat may be replaced, however, with a piece of cork linoleum, cut to fit, and painted any desirable color. A mix- ture of shellac and dry color, such as Venetian red, gives good results although paint or varnish will perhaps be more durable.—R. N. Roat, Kankakee, IIl. — less in. j T stru | met tenc a sh wid rails on ; | bolt | rails | up, | shot T witl agai the may hing in p | are | | long | end: | rails | as j | ther f I I n radi | the lic p cove bind } circ conr Ay in t] Vide shie] shor cabi: then Over Whi

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* me 2m. cap ims 1eir use ork. und the yer. olts this l be hen 2 is with ank. _ in- ms. ASES y to rims . file oper In it is yto the suc- ts a teur. ibso- nard. , and iable then st the bolts leter- with d, see perly. nbled e that clean. nspec- ertain ss are a, else ve too » tight oiling. s and grade. caskets ressure 2 that , keep cooled, each ts it, ts will 1e rear degree "pet or ywever, 5 tO fit, A mix- uch as though e more

HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

How to Construct Large Tables that Can Be Moved Easily | table games, party luncheons and various purposes, a large and sub- stantial table is often useful. It is espe- cially valuable if it will come apart readily for storage or moving. Of this type is the table illustrated. The original is 4 by 8 ft., the top being covered with green baize. It is used occasivnally during the winter months and at the be- ginning of the warm season is shipped to a summer house, where it is in constant use. A table such as this should not have | legs less than 3 in. square; 4 in. or more is better. The rails are 7¢ in. thick and not

hs

| a

BLOCKS pe ||!) JooweL

END RAIL DETAIL LEG DETAIL This general utility table can be taken apart for either storage or shipment less than 5 in. wide; they could be 7 or 8 in. if the table were larger. The illustration shows plainly the con- struction, which differs from the common | method in that neither a mortise and | tenon joint nor dowels are used. Instead, a slot is cut right through the legs the full | width and thickness of the rails. The end rails have square blocks glued and screwed on square with their ends to receive the bolts, as indicated. To keep these end | rails from twisting when the table is bolted up, one or two short dowels orscrews , should be used. The top may be made in one section with battens on the under side to fit tight against the rails and legs in order to keep the table square. If very large, the top may be made in two or more sections, hinged together. When the top is dropped in place, small iron plates or corner irons

Ill. ——— en

a

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Acme 30 Kilo Cycle R. fk. make you _ hand- some profits. Make mes tables, chairs, desks, screens, cabinets and all kinds of woodwork. You'll find a ready mark*t in yourn ighbor- hood. Easy to do—interesting work ~ big profits The Junior will do your ripping, mitering, rabbeting, te noning, grooving, sanding, etc., with ease and accuracy Saws 114 stock. Driven by 1-3 to 4 h.p. motor attac hed to any light socket. Sold On Absolute Money Back Guarantee Write for descriptive catalog on Bench Saws, Band Saws and Jointers W. B. & J. E. BOICE, 1730 Norwood Avenue, TOLEDO, 0.

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96 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Handling Machines Like Hand Tools At work with a hand tool, you see how the work goes on and how well the tool performs. But with the multiplied out- put of a machine tool or “auto- matic,’ you can see only from counter records how the work goes on and the machine works out. The machine—like the hand tool gives results according to how it is used and adapted to use. You'll develop its service like developing skill with a hand tool—using a COUNTER The small Revolution Counter be- low registers one for a revolution of a shaft, recording a machine operation, or product. Though small, this counter is very durable; its mechanism will stand a very high rate of speed, making it . especially — suit- | able for light, | fast-running ma- chines and most adaptable to ex- perimental work. If run backward the counter sub- tracts. Price $2.00. (Cut 4-5 size). Small Rotary Ratchet Counter, to register reciprocating movements of small ma- chines, also $2.00. Speed Counter Here’s the handiest instrument for finding revolutions-per-minute of a shaft or flywheel. You hold the tip of the counter against end of revolving shaft; press lightly when the second hand of your watch comes to QO; release pressure when minute is up. A spring clutch contro!s the recording mechanism. if (Cut less than 14 size) The Veeder Speed Counter enables you to keep motars, engines, generators, line shafting and machines operating at efficient speeds. Price, with two rubber tips (as illustrated) $3.50. FREE—The 80-page Veeder booklet of counters you’d like to see—and set working. The Veeder Mfg. Co. 44 Sargeant St., Hartford, Conn. | illustrated. How to Build a Gondola Swing | By Donald W. Clark AFE and thrilling fun for small chil- dren is furnished by the novel swing The youngsters sit in a like the miniature of a closed cabin | dirigible’s gondola. When once the swing has been started, it is kept going simply by pulling a rope that hangs down along- side the car. To construct the swing is not a difficult task for any man handy with woodwork- ing tools. A frame of 1 by 3 in. strips of =e ANGLE PLATES Ya XI" STRAP IRON Details of the unique swing, whi-h is kept in motion by pulling a control rope any strong, hard wood available is bolted and screwed together as for a conven- tional garden swing. This framework is 9 ft. wide at the bottom, 4 ft. wide at the top, 5 ft. deep, and 10 ft. high. In other words, it occupies a ground space of 9 by 5 ft., and the top is a rectangle 4 by 5 ft: Running across the top are two pieces 20 in. apart, each 10 in. from the center line, and from these the gondola is swung. Each piece has two metal bearing plates 2 ft. 10 in. apart to take the pivot rods, which in this case are lengths of 18-gage steel tubing 34 in. in diameter. One piece is 2 ft. long and the other 3 ft. 8 in. The latter extends on one side to the out- side, passing through a third bearing in the main frame of the top, as shown in the assembly view. It is to this tube that the control arm, which is 16 in. long, is fas- tened with a bolt, as indicated in the detail drawings. From the tubes are slung two rods 6 ft. 3 in. long from center to center of the bearing holes. These holes are reinforced with 1/16 by 1 in. strap iron, as detailed. The rod that connects with the tube having the control arm on it, must be bolted fast like the control arm. The gondola is built of light strips 14 by 2 in., with the exception of the cross bars to which the rods are pivoted. These are 1 by 3 in. and shaped as shown. A floor is provided only in the central section of the car and a seat, tilted backward a trifle for comfort and fitted with a back, is placed in each end. | Wallboard is used to cover the gondola and’the whole is painted with any bright! color and finished with spar varnish. The supporting frame also should be well painted or varnished. The car then is fastened to the swing rods by means of angles and bolts, as indicated, and a rope is tied to the control arm. Rebuilding a Porch Swing V HEN porch swings were quite high in price, a year or sO ago, we pur- chased one with a canvas instead of a cushion back. After putting up with this uncomfortable affair for two summers, the back was remodeled as follows: The cypress strip forming the support for the canvas back was removed and another strip was cut the same size. Three strips 34 by 2 by 18 in. were then screwed to the long pieces, one at each end, the other in the middle. Six more strips, 34 by 1 by 18 in. were screwed to the frame already made, spaced equally between the wider pieces. The canvas removed from the old back then was stretched tightly on the new frame and tacked to each cross piece. Excelsior was placed over the canvas and bound to each cross piece with cord. Over this a 2-in. layer of cotton batting, fluffed out slightly, was placed and bound with cord. Cretonne was used as a covering, and a cover to match was made to slip over - / SS ee | BACK FRAME “>, F*. sap-HOOKS” \_ | an [canna oe ee ; H = CANVAS’ COTTON “EXCELSIOR The wooden frame is covered with canvas. excelsior, cotton, and finally cretonne the old cushion seat. Cretonne also re placed the canvas side pieces. The new back was held in place by five snap hooks. The whole cost was about $4, but we had a swing that compared favorably with the $25 ones in department stores— and that was just as comfortable.—W. J: LAUBENSTEIN, Cleveland, Ohio. j _ ee

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| ot rods, 18-gage . One ft. 8 in. the out- aring in n in the that the , 1s fas- in the ods 6 ft. - of the inforced letailed. 1e tube nust be ps 14 by oss bars hese are A floor ection of ward a a back, gondola y bright | varnish. be well then is 1eans of d a rope

canvas, sretonne also re The new p hooks. _ but we avorably stores— fe:

| some point on this | line, roughly cen-

Cocoanut Shell Home Built to Suit Jenny Wren By Leroy William Hutchins ENNY WREN is a fastidious bird. And, having fine sensibilities, she must loathe the unsightly tin can to which she often is forced to resort for a home. It is doubtful, also, whether she admires the elaborate little man-type houses gen- erally built for her. For these reasons it is suggested that a cocoanut shell be used for her home. It is artistic, incon- spicuous, and cheap and easy to make. First sketch a line around the nut, midway be- tween the ends. At

The nest in place tered, draw a circle the size of a quarter dollar. Establish four equidistant points on the line and mark points 4 in. to each side of them, ejght in all. Mark another point about 1% in. | below the edge of the little circle, and a | second on the opposite side of the nut for | holes to receive a perch. Now, using a )-in. drill, bore holes at the eight points, make holes for the perch, ' and bore a ring of holes just inside the en- | and | ” trance circle. Drain out the “milk hacksaw the nut in half on the line. After breaking out the meat of the nut, which, of course, may be dried for cooking, the | halves are ready to be fastened together by running copper wire through the small | holes from the inside, a piece to each pair. | When all are in place, the ends should be pulled tight and twisted together. The shell then is ready for occupancy.

Folding Sheif for Child’s Bed Useful in Sickness | THE folding shelf illustrated is useful for holding medicines, spoons, glasses, and the like when giving attention to a child who is ill. Everything is in reach of the nurse and yet the shelf can be folded back out of the way of the pa-

[ Premera When not needed, the shelf folds back against the side of the bed tient simply by raising the board. It is made from the side of a wooden box to which is fastened rather loosely with | staples a length of 1<-in. wire that has | | been bent as shown.—H. W . LEUTNER. i il (i HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY : pi It That Every Man Interested In

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entjrely. half a century for this invention. One gallon, rctails | Dissolves sulphz $10.00, free to agents. _ LIGHTNING BATTERY CO., ST. PAUL, MINN. | LIGHTNING— Wonderful New Electrolyte charges discharged batteries instantly. | Eliminates old sulphuric acid method B Read From the pages of nearly every maga- zine a multitude of Schools, Institutes and Engineering Works bid for your attention. In the side panels of this advertisement,thelead- ing points that decide the issue are given. These Get all the ff . , TY Complete Training This is not_a short course in practical E) lectricity but a Complete Course in Elec- trical Engineering.

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Liberty Custom Made Top. It’s fun putting it on, simple direc- tops, side curtains and seat covers, for any make or model car. Dodgesand Maxwells. Write today for big money saving catalog. DRESS UP $3.85 YOUR CAR Ascedy looking top spoils its appearance. Get a ve a big labor bill. We are manufacturers of Special proposition for Fords, Chevrolets, TIRE 0., Dept. E38 Si ncinnati, Ohio

This year go with Radio. long, dull evenings. Take turn. usual. Simple to operate. weighs 15 lbs. comple te. $5.50. Big demand. balance on delivery. Ozarka Radio offers make money. Ozarka Agencies e ‘‘Ozarka Pian.’’ Don't

Radio Wherever Vou Go Vacation—Outing—Touring Make your vacation complete. Long-Distance Receiver with you. Get the sports returns— concerts—the special features of hundreds of broadcasting sta- tions. And, best of ail, you'll have it for home use when you re Ozarka is built for long distance—1000 miles is not un- equipped with aerial, ‘A” tubes, and one set of head See: Price complete ready tolisten in, $65.00. Order at once. Satisfaction guaranteed. Local Representatives Wanted a wondertul opportunity to Big money—easy sales. now Some, territory now open. You're interested, so write tovay for Camp, fish, hunt, tour with Radio. Liven up the rainy days and the new, wonderful Ozarka Portable, the Convenient and light tocarry. Only Case is a yar inches. C ompletely and ‘ ’ Batteries, three No. 199 Ready for instant use. Extra phones, Send $10.00, pay Over 1800 doing wonderful business. fail to give name of your county. OZARKA, Inc., 64 North Peoria St., Citeene

Page 100

“So you want to Set married, eh?” “That’s fine! I’m glad to hear it. But you know, Tom, just wanting to get married is not enough to justify an increase in salary. “Don’t depend on sentiment, or on any man’s favor, to bring you the salary increases you need s0 badly. Study your work—learn to know more about it than the other men in your department and you won’t have to come to me for an increase in salary. “Why don’t you take up a home study course with the International Correspondence Schools ? It’s been the making of Joe Browning and Dick Roberts and some of the other men around here.” Employers in every line of business are begging for men with ambition, men who really .want to get ahead in the world and are willing to prove it by training themselves to do some one thing well. One hour a day, spent with the I. C. S. in the quiet of your own home, will prepare you for the position you want in the "work you like best. Yes, it will! Put it up to us to prove it. Mark and mail the coupon to-day, INTERNATIONAL CORRESPONDENCE. SCHOOLS Box 7698-C, Scranton, Penna. Without cost or obligation on my part, please tell me how I can qualify for the position or in the subject before which I have marked an X: BUSINESS TRAINING COURSES []Business Management _} Salesmanship [ jIndustrial Management | | Advertising ]Personnel Organization _| Better Letters }Traftic Management [ 1Show Card Lettering ‘}Business Law _) Stenography and Typing Banking and Banking Law ] Business English [JAccountancy (including C.P.A.) L) Civil Service [} Nicholson Cost Accounting [ } Railway Mail Clerk “| Bookkeeping |] Common School Subjects [}Private Secretary CL} High School Subjects (J Spanish 0) French (Jillustrating TECHNICAL AND INDUSTRIAL COURSES Electrical Engineering [] Architect Electric Lighting Architects’ Blue Prints Mechanical Engineer [) Contractor and Builder Mechanical Draftsman ~} Architectural Draftsman Machine Shop Practice r} Concrete Builder Railroad Positions 7] Structural Engineer Gas Engine Operating Chemistry 0 Pharmaey Civil Engineer Automobile Work Surveying and Mapping : Airplane Engines Metallurgy Oj Mining [] Agrieulture and Poultry Steam Engineering () Radio § [ Mathematics MIND Locibehvaccseessbennacueksenbvveee sub bobscboerbssopsveconpobhosecbnevponenesssorosne Street 3-6-24 OMENS. oc Lbichbpiicb bbs opines vs ankesircnaseuntunsh ohecncouandeseesevbapcortsnssens Si ihigenceihcencitsusestniiecasvodneneiit III ss sshad civeisesitinsicashietiebnincaniaisarneioanet Oe sic ann cs s sascbeuhinabascnepacbbpusbsiabebsbussudkanetesksasaeseiens } «sons residing in Canada should se coupon to the ernational Correspondence Schools C anadian, Limited, Montreal, Canada SEND NO MONEY Big 3 foot Telescore in 5 Sections See people and objects miles away just like thoy were close, see Moon and Stars as you never did before. Brass bound, useful and entertaining. ‘‘Could es color of eo ety miles nh I ey aioe , r numbers on my 12 aa freight cars mile wa - GQ Pe oe mountains on moon’ rs. aie A. mer. Thousands pleased. SPECIAL OFFETS. Send just your name. E On arrival pay postman $1. plus few cents »stare. Satisfaction Guaranteed or money ic FERRY & CO., 630 Jackson Blvd., Dept. B-178 Chicago, fil I““STAMMERING| |fs Guse and dire * You can be quickly cured. Send 10 cents for 288 page cloth bound book on Stamme eae and Stutter- ing. It tells how I cured myself er Stammering HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY How to Clean and Refinish Your Motorcycle By Austin G, Tribute FTER two or three seasons a motor- cycle takes on a dingy and some- times battered appearance. The engine, | which may run just as sweetly as ever, has accumulated deposits of black, greasy mud, and the rough iron of the cylin- der fins shows red with rust. To restore the original bright, attractive appearance is work any rider may do himself. A thorough cleaning and re-enameling are necessary. The work should be commenced by taking the machine to pieces systematic- ally, the procedure varying with the different types of motorcycle. As a rule, the engine may be removed from the frame first, and following this, the tank, seat, wheels, mudguards, toolbox, and other accessories. The bolts and nuts of the several units of construction may be kept in labeled tin cans. The object is to separate the component parts so that they may be cleaned thor- oughly, as this is the basis of suc- cess in enamel- ing. Gasoline is one of the best sol- vents of dirt, and this used in con- junction with a Rubbing off the old enamel with steel wool and method cf painting the wheels putty-knife and an old brush will leave the surface ready for the removal of the old paint. Any of the paint removers on the market will be satisfactory. Apply the liquid with a brush, and with a handful of coarse-grade steel wool in your gloved hand, wipe the metal clean and bright. Removing the dirt and paint is the most arduous part of the job. At this point, make such repairs to the mudguards as may be necessary. In all probability they have become dented and loose at the riveted joints. Dents may be taken out with blocks of hard wood and a hammer. If the tank has shown a tendency to ooze at the seams, clean the leaking places well with emery cloth and solder neatly, smoothing with a file. Start the re-enameling with the applica- tion of flat white paint, such as white lead thinned with turpentine. This gives a (Continued on page 99) Home Protection with an ASTRA Automatic will cost little Nearly every man wants a gun in the house—he feels better able to protect his family. We are able to offer these Genuine Astra guns at special prices because we bought before recent tariff raises became effective. Really fine guns, beautifully finished, hard hitting. Use standard ammunition. Order direct from U. S. importers. 25 calibre—7 shot—C. O. Q. Automatic. 25 calibre—7 shot—Astra Automatic, 25 calibre Astra with triple safety. 32 calibre—10 shot Astra, extra magazine, 32-20 and 38 cal. swing-out cyl. revolvers. We guarantee every gun against defective work- manship; brand new; of Drop Forged Steel Through- out. Before buying any weapon INSIST on this guarantee. SEND NO MONEY unless you wish. State model desired—pay postman on delivery te Postage. Satisfaction guaranteed or money ree funded. Write for new firearms catalogue. CALIFORNIA TRADING CO. Dept. 17, Terminal Bldgq., Los Angeles, Cal. TO MEN FREE onry Illustrated booklet telling all about the health- bué@ding features of a new belt that’s formed to fit your hips, and a new buckle that EXPANDS AND CONTRACTS AUTOMATICALLY with every movement of your body. A true health belt—convenient, comfortable and dressy. Made in 14 different styles. Something brand new, and badly needed by every man who values long life. Send for this booklet. AGENTS—BIG COMMISSIONS Agents and crew managers are making big money selling EXPANDO belts and buckles. rite to- day for booklet, list of commissions and full de- tails of our Sx imple Outfit Offer. EVERY MAN'S A PROSPECT. EXPANDO BUCKLE COMPANY CINCINNATI, OHIO [SPORT BODIES for FORD and CHEV. 490 at $34. of Life-size : ie polteras $3 ae vane — You SLUNG canbuild PARTS 5 ww © Per Set body at $6.75 s3mall cost! We are manufacturers and oe, roduction enables us to quote exceptional low Jur unique {shipping methods save you 73% in FREIG T ‘CHARGES, Send _ at red i. fre bdD A ulars on Central Bodies. Our Book: ‘*HOW T BUILD A FO CER’ sent anywhere on receipt of 25c in cash or modal, Y! WR : ToD CENTRAL AUTO. SUPPLY CO. Dept. 122, LOUISVILLE, KY. “MAKE MONEY — AT HOME You CAN make $1 to $2 an hour — 3 cards at home in your spare time. @ and easily learned by our new simple bere 4 No canvassing or soliciting. Weshow you how, guarantee you work at home no matter where you live and per. you casheach week. Fullpar- ticulars and booklet free. Write to-day AMERICAN SHOW CARD SYSTEM LTD. Authorized and Fully Paid Capital, $1,000,000 206 Adams Bldg. to oronto, ‘Canada STUDY AT HOME Beco i Legally trained ae eA high need big success in busi- ness and public life. Greater Pee In ae now than ever — 2 Batodependent—pe a re yers e 3,000 to$ 10, 000 ) Annually We guide you B... b step. You can train at home during spare time. t us send you records an letters from LaSalle students admitted to the bar in various states. ee of LL. B. conferred. nds of el = students entolled. Low cost, easy terms. We asa ‘all text material, including fourteen: volume Law Librar; . Get our valuable 120-page “*Law G uide’’ end ‘*Evidence’ books FREE. Send for them—NOW. LaSalle Extension University, Dept. 783-L, Chicago 11924 BOOK OF BARGAINS Containing a full line of bodies and accessorie at P exceptionally low rices. Buy direct rom the factory. AUTO TIRE SALES CQ. and Stuttering for 20 years. BENJAMIN N. BOGUE 7507 Bogue Building, 1147 N. Ill. St., Indianapolis. gi ao sf wt ome TO — id 2]

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Refinishing Your Motorcycle (Continued from page 98) reflecting surface that will make more brilliant the effect of the following coats. Use only the best enamel in the color of your selection. With fine-grade sandpaper, smooth the priming coat when dry. Apply the enamel evenly, taking care to leave no brush marks. When this is thoroughly dry, sand again and apply the finishing coat. Suspend each wheel from a nail by means of a cord fastened to the axle ends, and the work of painting hubs and spokes will be facilitated. If the tire side of the rim is rusted, clean well with steel wool, and enamel. Also note any loose spokes, and remedy by a turn of the nipples. Parts of the engine that are not sub- jected to the intense heat caused by explosions and escape of gases, may be enameled; but the cylinders, exhaust pipes and muffler ought to have a coat of | stove-polish. Unless you wish to take the nickeled | parts to an electroplater for re-condition- ing. roughen them well with emery-cloth and cover with enamel. Striping requires more skill than most amateurs possess. The result will be good if sufficient care is taken; but it is advis- able to rely on the name of the manufac- | turer to give an ornamental touch to the

| if he knows where to look. tank. Buy two name transfers from an agency for your make of machine. With scissors cut within 14 in. the outline of the work, and after giving it a thin coat of varnish apply the transfer immediately to one side of the tank. With a damp sponge peel off the supporting paper. Repeat this process for the other side of the tank. In reassembling the parts, draw up all nuts carefully to insure their tightness. To retain the luster of the enamel, use soap and water (not gasoline) when washing; and if you have no garage, cover the motorcycle at night.

Dainty Trinket Box Made from Plank Cuttings

GP RES IG RE tos AGE ie 4

ss THE amateur carpenter and wood- worker can find a wealth of material In every car- penter’s or builder’s yard are plenty of odds and ends that can be made into most attractive articles. The little trinket or tobacco box illus- trated was turned from two end cuttings from a 2-in. elm plank. These had been glued together under considerable pres- Sure after the facing surfaces had been | planed. The outline was sketched on the end of a block that was to be the top of | the box, and then roughly cut in straight lines with a saw before the turning began. The inside of the cover, where it fits over the flange on the box, is turned with a slight taper, about one in eight, to in- sure a tight joint.—C. A. OLDROYD. ’ Free Bargain

HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

What It Does— Chmbs practically all grades on high’’; 80es through heavy, mud- dy roads with ease. Provides remarkable flexibility for city driving and congested traffic. Eliminates vibration; changes ra- tios at any speed; meets all vary- ing road conditions.

Makes Your Car or Truck TWO-IN-ONE! You'll get a new thrill out of motor car ownership, with the RUCKSTELL & AXLE-—let the other fel- {¢ low struggle up steep hills—you can pass him on “high”; you can go through any kind of roads; you can speed along on level highways and laugh back at the man in a high priced car. Go Anywhere! No need to invest your money in high priced cars when you can have a light car that will positively out-per- form any of them! You can go any- where—up in the mountains, through the lake regions over any sort of roads —cross country from coast to coast. The RUCKSTELL AXLE has solved the great problem for all time by com- bining POWER and SPEED. The simple movement of a handy lever provides TWO-PURPOSE PER- FORMANCE as needed. Insures Greater Economy! Save half in time, save on fuel and oil! Any way you figure, the RUCKSTELL AXLE is a blessing to owners of light cars and trucks. ‘, 4 v Lf eo’: e

4% * $3 hes CA . ”, San Francisco, Calif. In Canada: Ruckstell Axle Co., Ltd., Toronto and Montreal. Quis SRR S REESE REC REREREe eS Ag This coupon good for Free Demonstra- tion at nearest dealer, or for Free Booklet giving full particulars, prices, etc. (Dept.19A)

DUMINTON oes cuck vss cand vascsedecwenensacdedsdemesdeaaen Sau ese ueeaus

Motorcycle Bargains ,«<€ ¢; SAVE 25% to 65% yA on Slightly Used and Rebuilt Ke DS Motorcycles, Ace, Indian, Excelsior, Harley-Davidson, Cleveland, Side Cars, Johnson Motor Wheels, Evans Power Cycles, Bicycles. Send for Bulletin and Money Saving Message, listing hundreds of bargains in used, rebuilt and new machines, supplies, accessories, etc. AMERICAN MOTOR CYCLE CoO. Dept. 726 2047 W. Chicago Ave. CHICAGO A $500 Cash Prize is offered for the best second verse to “’’?LL BE WAITING’”’ Those wishing to compete may receive a free copy of this song and rules of contest by addressing EQUITABLE MUSIC CORPORATION 1658 Broadway, New York City

eeps Radio

Batteries It’s important to keep radio bat- teries charged when you're away for the summer. APCO Battery Charger does this overnight—without disconnecting set—and for less than a dime per battery. It’s noiseless, clean and as easy to hook up as your elecric flat iron. There’s an APCO Charger for ‘‘A” and ‘‘B” batteries. Write for interesting circular and nearest dealer’s name. APCO MFG. CO., Baker St.. Providence, R. I, Nl lien

Page 102

Write Today For Descriptive Folder of the New Howard 5-Tube Neutrodyne This remarkable set has created a sen- sation among Radio enthusiasts. Beautiful Black Walnut Cabinet with

special Howard Neutroformers Tube Sockets and Rheostats. 4 = a, Licensed by cD '&D, A a) S aadent UTi R ODYN Ss & G w s Z & UTRODYN Q R Other Patents Pending S00g5* Howard Manufacturing Co. 4240 No. Western Ave. Chicago, III. ©

—_ 500° PROFIT AG ENTS 3007, Genuine Gold Leaf Letters GUARANTEED TO NEVER TARNISH For store fronts, office windows. Bank windows, Doors, Panels, Signs, Trucks, omol and Glass ns of all kinds. Any one can put ther m on an d money right bce n t without pre

$28. 70.’ IL Srbice os ade $835°00 in six woke. $60 io $200a Week GENERAL AGENTS—'* is cas point sub-

. We pay you 20°% cash commission on all orders we receive from locé il agents appointe a by you anywhere. W: allow you 50 dis t ‘ . can sell to nearby t ae) ou . as you please. large aes nand for window lettering everywhere. Write today for tree sample, ) full par- ticulars and liberal offer to Metallic Letter Co., general agents.

433-A N. Clark St., Chicago

OW a discarded washstand may be made attractive most is no shown into an and use- ful desk, with very little work and al- expense, in the accompanying illus- trations. Obsolete Washstand Converted into Neat Writing Desk

The lower shelf is used for making the hinged cover, and packing boxes will sup-

The old and useless wash- stand is shown above. With a few boards from boxes, it was made into the attractive writing - desk illustrated at the left

ply the back, ends, narrow top pieces, and pigeonholes. Desk hinge supports or hinges and chains for the shelf, and a good varnish stain are the only supplies to be pur- chased.—GRACE SCHOETTLER, Buda, Ill.

Ejector for Cigarette Holder IGARETTE smokers should appre- ciate this ejector for disposing of butts in a cigarette holder. Drill a very small hole close to the large end of the hoider. Then bend a piece of 3/16-in. wide aluminum ribbon or soft cop- per ribbon to fit inside, as_ indi- cated. <A hole is cut in the ribbon to allow the cigar- ette to draw freely. SMOKE HOLE - Cigarette ejector

One end of the metal is riveted to the holder and the other is free so that it can be pulled out sufficiently to dislodge the shortest butt.—L. B. Ropsins, Harwich, Mass.

How to Fix a Balky Fan (Continued from page 74) nections and ends of wires, | moving the tape or binding cord where necessary. course, windings. Which page 74. (Fig. 6 line, struction card calls gear box of the oscillator is of the fan carefully re- The test lamp method used for examining the starting coil can be used, of for further testing the motor of these repair methods to try, vou may judge by reading the chart on When the trouble has been cor- rected, reassemble the fan, fill the oil cups with hard oil, petrolatum, vase- oscillating type, out and pack with hard oil. All that remains is to start the fan and HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY STOP USING A TRUSS

Then open the (hig. 7); clean it sit back and enjoy the breeze.

or whatever lubricant the fan in- | if the | Do Away With Steel And Rubber Bands ive to secure the PLAPAO-PAD firme vet—easy to apply. Over 250,000 Now In Use We have proved to hundreds of thousands of sufferers from hernia (rupture) that to obtain lasting relief and develop a na process for betterment comes by. wearing a Plapao-Pad. This patented h ico device can do the same for you. The wearing of an improper support aggravates rather than improves the condition, The Plapao-Pad can and does aid the muscles in giving proper support, thereby ren- dering efficient aid to Nature in restoring strength to the weakened muscles. Being self- adhesive there is no slipping and shifting of pad with resultant irritation and chafing. Most comfortable to wear—no delay from work. Awarded Gold Medal at Rome and Grand Prix at Paris, ay =6Send No Money

We will send you a trial of Plapao absolutel E,, you pay nothing for this trial now or later. rite for it today. also full information. PLAPAO LABORATORIES, Block 716 St. Louis, Mo.

Radio Dealers: Send for protected Agency proposition on Monodyne Apparatus JRPRO \ 4 RPHONK 16 HUDSON STREET NEW YORK

neon yourself as a appa nc Expert quickly—during your spare tim era leading photographer. I'll show on how to start your own business—or command a large salary. Send for my un- usual offer—it’s any temporary. Actat once. A postal will do. Aaa Studios, Inc., Dept. AE O1 Michigan Ave., Chicago, U.

Your FREE | learsnin: Skin Can Be Quickly Cleared of Pimples, Blackheads, Acne Eruptions on the face or body, Barbers Itch, Eczema, Enlarged Pores and Oily or Shiny Skin. Write today for my FREE BOOKLET, A CLEAR-TONE SKIN,” telling how I th myself after being afflicted 15 years. $1000 Cash says ! canclear your skin of the above blemishes. E.S. GIVENS, 153 Chemical Bidg., Kansas City, Mo.

hw eninaron COAL COMPANY ‘Eicon Exchange Bulging, Chicago, Minois

é ge i c

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e red of ions on cezema, y Skin. OOKLET, ng how 415 years. blemishes. sity, Mo. o HERE'S an immense field of radio en- joyment in summer, (the best political orators in America are on programs)—but you must have extremely sensitive reception apparatus to get good results. Stromber¢ Carlson Head Sets and Loud Speakers have powerful magnets, the sensitivity of which gives them wide range, bringing in the fainter signals with volume and clear- ness. They also have layer wound and layer insulated coils—an exclusive Stromberg- Carlson type of construction—which will stand up under the high plate voltages now used, Ask your dealer Stromberg-Carlson Tel. Mfg. Co. 1060 University Ave., Rochester, N.Y. Layer Wound an Layer Insulated TUDEBAKER| 21 Phe Insured Watch Jere | Pey In easy monthly payments and gel. a Studebaker, the lifetime watch, direct from the factory at lowest factory prices. : sone 8 ——— ine W e zt e cluding heat, cold, isochronism an sitions. Write for Style Book show- rl ng 54 newest, thin-model designs. ve Sent FREE. Ask for Bracelet Watch folder leas emazing Studebaker Chain FREE Ww ile offer facta: A vance Watch ‘Styles Post Card willbring details and book free/ und $1 down offer. Studebaker Watch Co., Dept. 237 South Bend, Ind. Send a postcard or letter today for PATENTS BOOKLET FREE HIGHEST REFERENCES PROMPTNESS ASSURED REST RESULTS Send drawing or model for examination and report as to patentability WATSON E. COLEMAN, Patent Lawyer 644 G Street N. W., Washington, D. C. Tt PROTECT PATENTS IMPORTANT © INVENTIONS Mason, Fenwick & Lawrence, Patent and Trademark Lawyers, Washington, D. C., New York and Chicago. Established over sixty years, Highest references. HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Making Use of Cut Film in Camera Plate-Holders HE present widespread use of cut film instead of dry plates for photographic purposes has led to the abandonment of many plate-holders. By making simple adapters, however, the photographer can utilize his plate-holders for films. A piece of cardboard approximately the thickness of a dry plate, or a trifle less, is cut the de- sired size. This board is then covered with photographic black paper, firmly pasted on the reverse side. On the front, four cuts are made across the corner, as indicated in the illustration, to form four corner pockets. The cut film is then inserted in this adapter and the whole loaded into the plate-holder. Kits may be made easily in the same way to adapt smaller sizes of film to large plate-holders, as shown. They are also serviceable in adapting American film to foreign sizes. For instance, the 214 by 31% in., which is more widely used in foreign cameras than our’ own 214 by 314, may be cut from 5 by 7 film without waste.—HERBERT C. McKay. BLACK PAPER SLITS IN PAPER The construction of a film adapter How to Give Aluminum Paint a Durable Gold Color Pel paint, although beautiful when first applied, soon tarnishes, and it is expensive for large surfaces. Real gold leaf is absolutely permanent, but is difficult to lay and still more expensive. A beautiful permanent gold-like surface may, however, be obtained by using aluminum paint and then coloring the surface as follows: Dissolve by digestion gum sandarac alone or equal parts of this and bleached shellac’in alcohol, adding tumeric and dragon’s blood in the proportions of 12 oz. sandarac or 6 oz. each of the sandarac and shellac to 1 oz. tumerie and 2 oz. dragon’s blood to 1 gal. alcohol. Larger or smaller amounts should be mixedinthesame proportions. Filter this through a cloth and apply with a soft brush. Solid aluminum articles may be treated in the same manner. Bushing Serves as Simple Die HE experiments of a home worker ij j called for a number | of small sheet-metal disks and, as no punch press was available, a simple hand punch and die were made, as shown. The die is merely a_ bushing with a saw slot in which the stock is placed. The punch is driven through by’a mallet blow.—R. H. KAspEer, Phila- delphia, Pa. STOCK INSERTED IN THIS SLOT = — -- wot ee — mee -- ms In Tight , Places! HERE you can move crank only an inch back and forth, ‘“SYANKEE’?’ DOUBLE Ratchet keeps bit cutting continuously. Save time and labor in boring hard wood or light metal by using a “Yankee” Hand Drill, fi eer hace N “YANKEE” Ratchet Hand Drill No. 1530 Only 101% in. long. Weighs only 114 Ibs. Has all five adjustments of big** Yankee” Ratchet Breast Drill. Some Other ““YANKEE’’ TOOLS Spiral Screw-drivers Quick Return Spiral Screw- drivers Ratchet Chain Drills Ratchet Breast Drills Bench Vises—removable base FREE Tool Book Illustrates and describes ail “Yankee” Tools for saving time and effort. Dealers everywhere sell ‘‘Yankee’’ Tools “YANKEE” TOOLS Make BettOv Mechanica Nortu Bros. Mre. Co., Philadelphia, U.S.A.

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This Radio Battery Has “Over Twice The Life” HE Burgess Radio “A” is exclusively a radio battery, designed especially for service on the ‘“‘A’’ or filament circuit of dry cell vacuum tubes. In Radio service it has over twice the t life of the ordinary No. 6 ignition battery ... costs approximately the same ...has a rapid recovery to high voitage after short periods of rest... practically no voltage is lost when not in use. Replace your worn out “A” battery with a Burgess. Compare the service in your own set under any and all condi- tions. Then Jet your experience guide you in your future purchase of Radio ‘A,’ ‘B’ and ‘C,’ batteries; there’s a Burgess Bat- tery for every radio purpose. ‘ “ASK ANY RADIO ENGINEER” BURGESS RADIO BATTERIES BURGESS BATTERY COMPANY Engineers - DRY BATTERIES - Manufacturers FLASHLIGHT - RADIO - IGNITION - TELEPHONE General SalesOffice: Harris Trust Bldg.,Chicago Laboratories and Works: Madison, Wisconsin “WONDER” COLD PIPE, HAND and MOTOR OPERATED ‘ 14 Sizes of Machines What it costs to bend pipe our way. Per bend. Delage 1"’ pipe B cents 4°" pipe 25 cents ~ hye 2’’ pipe 10 cents 6’’ pipe 60 cents U 8°’ pipe $1.00 oO Send for Catalogue. AMERICAN PIPE BENDING MACHINE CO. 51 Peart St. Boston, Mass. HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY a) * & mome hipshape ONE of the most frequent plumbing complaints in the Clogged-Up Trap average home, aside from leaking faucets, is that of stuffed or clogged sink traps. Without the proper tools, this is often most difficult to remedy. When confronted with this problem recently, the writer used a piece of scrap flexible automobile speedometer shafting with great success. One end of the flexible shaft was frayed. This was inserted into the clogged trap and given a twisting motion. The ae Cleaning a stopped-up trap with a length of discarded automobile speedometer shafting material that clogged the trap was securely enmeshed so that it could be pulled out of the trap instead of being forced into the drainpipe, as would have been the case if a force pump or wire had been employed. The shafting, which had been bought from an auto-wrecking concern for 20 cents, is now numbered among the writer’s most valued plumbing tools. A short length of ‘“BX,’’ a flexible material used by electricians, may also be used for this purpose, but this material does not possess the great degree of flexibility- of the speedometer shafting. An ordinary coilspring also can be used, as described in the February issue of POPULAR SCIENCE A sturdy, dependable motor ear. Any handy man or boy can build it. Rower famous 234 MONTHLY.—JOHN H. SCHALEK, Pitts- burgh, Pa. Bath IF you need a atnroom small shelf in a Shelf modern bathroom, or in any room where there is no suitable wall space, look around for a steam or hot-water pipe. Such a pipe will support a shelf about 9 in. in diameter. One has been used for more than a year to support an electric stove, so the shelf is strong enough for any ordinary purpose. Cut a piece of 1-in.-thick whitewood, oak, or other wood to the desired size, smooth it with sand- paper and screw it to an ordinary ja- panned iron _ shelf bracket, costing 10 cents. Hold the bracket against the pipe with a 5-cent automobile radiator hose clamp. A single clamp at the upper end of the bracket will be sufficient. The shelf may be either round or hexagonal and enameled white. If a stove is to be placed on the shelf, protect the wood with sheet metal or thin asbes- tos.—M. MacDOonaLbD, Brooklyn, N. Y. RADIATOR HOSE CLAMP Cleaning oes eee nished surface is Varnish not cracked, checked or peeling, but merely needs freshening up before it can be revarnished, I find the following method of cleaning is exceptionally satis- factory: Dip some medium fine steel wool in slightly warm water and rub it over a bar of mild laundry soap until it lathers. Then scrub the woodwork with this until the dirt is loosened. Rinse clean with clean cool water. Let the wood dry thoroughly and apply one coat of varnish thinned with turpen- tine. When this has dried hard, rub down with fine steel wool and put on another coat of varnish as it comes from the can.—A. J. HARSTAD, Wolf Creek, Mont. A SERVICEABLE shoe rack inside a Shoe Rack closet door can be made from two flat curtain rods. The top rod has a projec- tion of 4 in., and the lower rod a pro- jection of 214 in. The heels of the shoes Curtain-Rod Rack made of two flat curtain rods attached to inside of closet door hang on the top rod and the lower rod keeps the toes in place. This type of rack saves space and the shoes are kept in better order than if they were stacked on the floor or a shelf.— KENNETH B. Murray, Sturgis, Mich. omy & E .

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or ct 2»S- T- is yut ‘an ing tis- in ra ers. ntil rith ply yen- rub on rom eek, BLE lea . be flat yjec- pro- hoes

r rod d the they elf .— ch. | | | | which I was go- | ing to build the

=, The Shipshape Home | (Continued from page 102) | | LAYING bricks is | not as easy as it Bricks looks, as most home workers who try it | soon find out. I recently had to replace | some brick underpinning beneath my | house. What I did was to get a straight “two by four” a little longer than the | wall was to be and placed it as a guide against the piers between

Laying

wall. This gave me a_ straight line to begin with, and then, as I finished each course, I raised the “two by four’ by | placing bricks beneath it, in each case | allowing the edge to project about 1 in. | above the edge of the course already laid. | After each course, I smoothed mortar | into the crevices and took care to run | the trowel over the face side of the | timber, so that it would fit snugly against the guide piers at the end. | If there had been no piers, I should have | placed posts of substantial straight timber | to guide the end of the ‘‘two by fours.”’ | This method soon gives the amateur | mason a knack of.laying bricks straight. | —GEORGE T. BROSKI, Dumbarton, Va.

SS ! 2x4 STRAIGHT EDGE

Kitch Hanpy hooks for itchen hanging the range Hooks shovel, dustpan, dust brush, stove poker, and various kitchen utensils, can be bent up easily from pieces of galvanized iron wire, about No. 8 gage and 12 in. long. Fasten each hook on | the hot-water pipe extending from the back of the stove. Very heavy ar- ticles or a great number of them, should not be hung on the pipes, which might sag, but small articles will do no harm.

aT? IN PAINTING old Filling floors the cracks be- Floor Cracks tween the boards often present a diffi- cult problem. Ordinary prepared crack- fillers are apt to crumble and leave un- sightly gaps after a few months, if they are used in fairly wide cracks.

A method that has stood the test of | years is to saw from -in. number of strips varying in width from 1/16 to 14 in. in thickness and 3 or 4 ft. _long. After brushing the dirt from a crack, choose a strip that will just fit into the space, coat it with glue on both sides | and drive it into place. A larger strip | 0f wood should be used to protect the stock a | | thin strip while it is being hammered into | the crack. These strips easily can be planed to fit | any crack, and a lasting job is the result. ‘ie P. BURBANK, East Milton, Mass. | HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

OUR Methods, Terms, PATENTS, petition in trade.

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Page 106

104 Your Way j to Success i and Social Popularity The man or woman, boy or girl, who can play the Saxophone finds a cordial welcome everywhere. For school, lodge, church or home entertainment the Saxophone has no equal. No other instrument has ever won such universal popularity in so short a time because no other instrument has that rich appealing tone and is productive of so many sur- prising orchestral effects. Many of the leading saxophonists in the country have proved that the Saxophone is a legitimate instrument. Only recently a very successful saxophone recital was given in Car- negie Hall. In most cases these artists are playing . True Tone The same kind we offer to you on easy payments—if it {fs not convenient for you to pay cash. We also allow 6 day s’ trial—in your own home. You will enjoy every minute while you are learning and soon be able to enter- tain others, with profit and advancement to yourself. Easy to Play—Easy to Pay Write for Free Saxophone Book today. Then select the instrument you want. Within an hour you can play the scale—within a few weeks play popular hits and in 90 days take your place in band or orchestra. Write tor the Free Book today. BUESCHER BAND INSTRUMENT CO. Everything in Band and Orchestra Instruments 3184 Buescher Block, Elkhart, Ind. Buescher Band Instrument Co. 3184 Buescher Block, Elkhart, Ind. | Gentiemen: I am interested in the instrument checked below: Saxophone. __-Cornet._.Trombone_-___Trumpet (Mention any other instrument intercsted in) Hand paar 8 perfect letter in a jiffy. Prove it your- I23 7 10 cents. Free with order, b etc Book with illustrations of 100 Mechanical PATENTS Copyrights s iaaiahicdihceiiiaaseni ai Your Own Signs and FAC WA LETTER Sitw Cards tke quick EASY WAY A mR C You, too, can make striking, forceful signs and show cards with the aid of ER PATTERNS. self and save money. Extra introductory offer. All capital letters 1 1-2 inch, all small letters 1 inch, also set of 10 number patterns 1 1-2 inch, styles as shown. All 3 sets $1.00 postpaid (regu- JOHN F. RAHN, K2433 N.Greenview Ave., Chicago, Ill. TRADE-MARKS, COPYRIGHTS AND PATENT 5 canon Jrite for advice and instruc- | Movements sent free on request. | ALBERT E. DIETERICH Patent Lawyer and Solicitor | Successor to Fred G. Dieterich & Co. Patent Litigation Handbook of instructions, ‘‘How to Protect In- ventions,”” sent free on request. R. H. FRAVEL, Patent Lawyer Formerly of the U. S. Patent Office Examining Corps Just lay the pattern down—trace around it—and value $1.25). Samples of 10 different styles tions how to proceed, costs 681A Ouray Bidg. WASHINGTON, D. C. Trade Marks Room 2503 McLachlen Bldg. WASHINGTON, D. C. How to Build an Icebox (Continued from page 71) substances, is durable, and does not split or deteriorate. To make the case, four 34-in. (or }%-in.) boards are nailed together temporarily and cut and planed to a finished size of 7% in. wide and 3 ft. 9 in. long. A leg 3 in. wide and 3 in. long is then laid out and the waste material is cut away so that the boards then can be opened out and made into two side pieces, as shown in Fig. 2, SOLDERED diate ——= CORK WOODEN FRAME jj 124ix20" ee DRAIN ) yas TURNED-UP ENDS Wood PAPER ao WIRE NET SHELVES Fig. 3. and water Details of ice deck, baffle, drain, seal, insulation and shelving the boards being nailed and_ glued together. The top, 167¢ in. by 2 ft. 11 in., is then glued up and nailed on with finishing nails, set with a punch. The bottom piece, the same width and 2 ft. 8 in. long, is fastened in position and supported at the ends by 1 by 1 in. strips. The back is 3¢-in. thick tongue-and-groove ceiling. The box is lined with odorless insulating paper, held in place with shellac. All the edges should be lapped and cemented. Then obtain a quantity of 2-in. cork- board, which is made up in slabs 3 by 1 ft. Cork is cut easily with a coarse-toothed carpenter’s saw. Shellac, into which has been stirred some whiting to thicken it and give body, is used to cement the cork to the insulat- ing paper. The corkboard is fastened to the wooden casing with 214-in. flat-headed nails. These nails will sink into the cork about 14 in. Too much force must not be applied or else the nail will be driven through the wooden casing. Upon the 2-in. layer of cork another 1-in.-thick layer is applied. Care should be taken to “break” all joints, as shown in Fig.3,and make them square and clean cut. All the seams should be sealed thoroughly with the shellac compound, which also is used to glue the second layer of cork to (Continued on page 105) | HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY puns Toe ia O FOR ul a U2 eit By ES DON'T LOSE YOUR RIGHTS} TO PATENT PROTECTION Before disclosing your invention to anyone ff send for blank form *‘EVIDENCE OF CON- ff CEPTION” to be signed and witnessed. | sample form together with printed instructions will show youjust how to work up your evi- dence and establish thesame before filing ap- plication for patent. As registered patent at- tornevs we represent hundreds of inventors all Mover the United States and Canada in the ad- yancement of inventions, Ourschedule of fees willbe found reasonable. "The form “Evidence of Conception,’’ sample, instructions relating Neto obtaining of patents and schedule of fees RB sent uponrequest. Ask for them,—a post card will do. 274 Ouray Bldg. WASHINGTON, D. C. Originators of forms “‘Evidence of Con ception.” To the Man With an Idea I offer a most comprehensive, ex- perienced, efficient service for his prompt, legal protection and the development of his proposition. Send sketch, or model and description, for advice as to cost, search through prior United States patents, etc. Pre- liminary advice gladly furnished with- out charge. My experience and familiarity with various arts, frequently enable me to accurately advise clients as to prob- able patentability before they go to any expense. Booklet of valuable information and form for properly disclosing your idea, free on request. Write today. RICHARD B. OWEN Patent Lawyer 6 Owen Building, Washington,D.C. 2276-D Woolworth Building ade New York City Cheapest Way to Go to work orschooland recreation ison » a Ranger bicycle. Chuice of 44 stylesand [Ay sizes 00 Days Free Trial. Express prepaid. ga y $5 aMon if desired. Saved time Reed and carfare easily | meets the small monthly payments, + Parts, ui) nt — ires prices. Send non ~ Se ent remarkable factory prices and marvelous terms. Write us today for CY Cal DEPE.H109 CHICAGO @ree catalog ENSATIONAL SA GUARANTEED TYPEWRITERS Limited quantity fully guaranteed S~ standard make typewriters. S Days »iFree Trial. Lowest prices ever offer- i Jed. Some at $45.35. Easy payments as low as $3 monthly. Send today for FREE booklet of Valuable Typewriter Informa- tion and Special Sale Bulletin “Smith Typewriter SalesCo. 321-36@ East Grand Ave. Chiczgo, Ill PR Neen righ

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HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY How to Build an Icebox (Continued from page 104) the first. Too many nails must not be used, for steel is a conductor of heat. A lining of 16-gage galvanized iron is made to fit snugly into the wood and cork | ease. This is simple work, because only 5 soldered seams are necessary. The top, | sides, and bottom are bent from one sheet | and the back is another sheet. The deck and baffle can be made up by the worker as described below and | turned over to the tinsmith for covering | with metal at the same time the lining is to be made. The deck is constructed of 1 by 1 in. | strips, as shown in Fig. 3. It is insulated | with two inserted cork sections of 1-in. | cork. The whole then is covered with | light galvanized-iron sheeting. First one sheet, the width of the deck, is applied, and then another sheet, the under one, is | fitted so that it extends around and up the ' sides for about 34 in. It is soldered as shown in Fig. 3 and is finished by having two ends soldered on, one of which should have a close 3¢-in. nipple soldered in it. Upon this is screwed a 3¢-in. ell, forming part of the drain. Galvanized nails should be used in nailing the sheet metal to the wooden frame so that the heads may be soldered over. Two 22-in. lengths of 34-in. galvanized angle iron are obtained. One end of each is split down its length for a distance of 2 in., the ends then being turned out, as in Fig. 3. These are soldered to the deck. The splayed ends of the iron runners pre- vent the ice from sliding down and pro- jecting over the air chute. HE baffle, which has a 5 by 10 in. opening at the bottom, is built like the deck—1 by 1 in. strips with 1-in. cork | insulating insertions, covered with gal- | vanized sheeting. The deck is soldered in as shown in Fig. 1 and should be 11 in. _ from the top at the drain end and 10 in. from the top at the other end. The baffle at the drain end is about 2 in. from the side; the other end of the deck is about 3 in. away from the side wall. The baffle is soldered to the lining and to the deck so that it is 2 in. away from the side wall. Before placing the lining in the case it is | best to solder in the 34-in. galvanized angle irons that support the shelves. Generally two shelves are installed, the | first 5 in. from the bottom, the next 5 in. from the first. The construction of the front of the box is as shown in Fig. 2. Only the vertical center piece needs to have cork insulation and be covered with galvanized iron. To the center piece, betwecn the two service doors, are soldered the angle irons that carry the shelves. The shelves are constructed of steel screening with a heavy galvanized-wire _ edging, the screen edges being bent over | the wire edge. These are made 11 in. _ long by 12 in. wide, placed in pairs. _ The swinging flap, which may be elim- inated if a drain is provided in the floor, 1s to conceal the drip pan and swings upon two pivots. These pivots are made by | Screwing two heavy wood screws into the | upper edge of the flap, one at each end, = (Continued on page 106) SUPREME COURT DISTRICT OF COLUMBIA, | TRADE MARKS. COPYRIGHTS PROTECT YOUR IDEAS ANY NEW article, machine, design or improvement thereof, or any new combination of parts or improvements in any ]:nown article which increases its efficiency or usefulness, may be patented, if it involves invention. If You Have Any New Ideas which you feel are useful, practical and novel, take prompt action to protect your rights. If you have invented any new machine, or new combination of parts, or improvement, or any new design or process, SEND DRAWING, MODEL OR DESCRIPTION of it for information as to procedure to secure protection. Write Today for Blank Form ‘Record of Invention”’ USE THE COUPON attached, and immediately upon its receipt I shall send you this form to be returned to me with drawing, description or model of your idea; promptly upon receiving your idea I shall write you fully as to procedure and costs. 105 DRAFTING and SPECIFICATION ROOM of CLARENCE A. O’BRIEN, Registered Patent Attorney, Washington, D. C. No Charge for Above Information All communications are held in strict confidence. My personal, careful and thorough attention is given to each case. I offer you efficient, reliable and prompt service—based upon practical experience. Highest references. WRITE TODAY for free book ‘‘How to Obtain a Patent.’’ This book will gee ey valuable information, and it may save you much time and effort. Send for it A My practice is devoted exclusively to United States and Foreign Patents and Trade Marks. Write me freely, frankly and with full confidence; it is very probable that I can help you. Write TODAY. REGISTERED PATENT ATTORNEY | MEMBER OF THE BAR OF SUPREME COURT OF UNITED STATES, COURT OF APPEALS DISTRICT OF COLUMBIA UNITED STATES COURT OF CLAIMS Practice Confined to Patents and Trade Marks 884 Security Savings & Com’l Bank Bldg., directly across street from U. S. Patent Office, Washington, D. C. ee ee es ee ee ee ee ee ee ee ee ee ee, ee ee ee ee ee ee ee ee ee ee ee ee ee CLARENCE A. O’BRIEN, Registered Patent Attorney, Washington, D. C. 884 Security Savings and Com’l Bank Bldg., directly across street from U. S. Patent Office. Please send me your free booklet ‘‘How to Obtain a Patent” and blank form *‘Record of Invention”’ without any obligation on my part. (| RR ery a Important — Write or - Print clearly PL EO. a ee Pe PENT Cee oe ee

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A few cents a na will pay, Instruments and complete outiits at factory prices direct to you, WuRuizel 800 YEARS The Rudolph Wurlitzer Co., pent. 8178 i 117 E. 4th St., Cincinnati —329 So. Wabash Ave., Chicago 120W, 42ndSt., New York—250 Stockton St., San Francisco Send me your new catalog, which illustrates and describes every known musical instrument, many of them shown in full colors, all at lowest factory | prices, Also tell me how I may have any instru: ment on a week’s trial in my own home at your expense and without obligation, and may pay for | it on your special easy payment plan. a nea ee Address ~~—- eapeciaily tuterested) aA Warlitzer Co. —s (State instrument in which you, queen Copyright 1922, The SS, HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Unique Method Simplifies Darkroom Development HE developing device for small roll films illustrated has three advan- tages: It requires minimum developer; | it allows the film to be handled without the hands coming in contact with the solutions, and it enables the photographer to inspect the progress of development without having to touch the film itself. The film is wound on a glass tube or an | incandescent gaslight chimney in spirals without overlapping. If non-curling film is used, the black paper also should be wound on the tube so as to lie between the film and the tube and prevent the gelatine’s sticking. The ends of the film are thumbtacked to cork stoppers in both ends of the tube. A wire loop is attached to the top stop- per to serve as a handle and three or four BRASS WIRE HANDLE ‘% | WOODEN )\, STOPPER “THUMBTACK | “GLASS TUBE _o7 FILM WOODEN DISK, U I[p7"GLASS i |D-i6° JAR ee ae . _WOODEN ~ STOPPER eo’ Le THUMBTACK hit=+Aeeer ~=-BRASS WIRE NAILS Wound around a glass tube, the films are placed in a jar containing the developer, brass nails are driven into the lower stopper to within % in. of their heads to center the tube in the developing jar. The latter should have an_ internal diameter (D) about 14 in. greater than the diameter of the tube. Before the top stopper is finally fixed, the tube is ballasted with several old nuts held in position with a few spoonfuls of plaster-of-Paris solution. If three glass jars are provided for developer, fixing bath, and rinsing water, there is no need to touch the film until it is ready for uncoiling and drying. By cutting holes about 1 in. in diameter in the black backing paper, before winding on the film, development can be checked simply by holding the glass tube against the red light. A further advantage of this method of development is that the developer can be left in the glass jar, ready for further use, provided an airtight cover is made of wood boiled in paraffin.—C. A. O. How to Remove Road Tar OAD tar should be removed immedi- ately after an auto is housed. If left indefinitely, the paint will come off with the tar, leaving the surface unsightly. Gasoline will remove tar when fresh and soft, but after a very short time this is use- less. Either lard or oleomargarine will soften the tar after it has begun to harden, that is, soften it enough to be removed | without taking the varnish with it. Cocoa- butter also will be found a harmless solvent for tar. How to Build an Icebox (Continued from page 105) | and then cutting or filing off the heads. The pivots swing in the 34 by 3 by 8 in. pieces that are nailed to ie front legs, as shown in Fig. 1. The ice door is constructed of 14-in. stock, lapping 14 in. on all sides of the opening. The edges should be beveled and smoothed. The hinges and the catches should be of the regulation offset type, obtainable at any large hardware shop. A sheet of 1-in. corkboard is applied to the doors, the edges being beveled, as shown in Fig. 1. The lower left-hand door is the most difficult to fit because the cork has to be trimmed to allow the door to close without jamming against the baffle. However, this requires but slight trimming. All the cork insulation then is covered with a galvanized metal cover. The doors should be hung so that 14-in. refrigerator packing, which may be pur- chased in the larger hardware supply stores, can be placed as shown in Fig. 1. The front is nailed to the completed box with long finishing nails, care being taken to see that the deck is properly nailed and supported, and that the baffle is held in place by several of the wire nails. F TER careful measurements have been taken, aholeis drilled through the bot- tom, and a piece of 3¢-in. galvanized pipe is cut and threaded so as to extend into the box. It is screwed into the ell of the deck. A small amount of white lead ap- plied to the pipe joints will seal them per- fectly and at the same time eliminate the necessity of using force in order to obtain a tight joint. Care must be taken not to break off the soldered nipple. The methods of forming a trap for the drain is clearly indicated in the detail of the piping. The offset in the horizontal pipe should be as small as will serve the purpose of holding enough water in the trap to act as a waterseal. The water may be discharged in any desirable place, the usual practice being to carry the drip pipe to the center and provide it with an ell, facing down, as shown in Fig. 3. Ifa drain seal from an old icebox can be obtained, it may be used instead. In cleaning the trap, use lye and hot water and, if necessary, unscrew the plug, as in cleaning a regular sink trap. Care should be taken so as not to block the screen shelves, especially the cold air exit, with large boxes, or other objects. The cooled air flows down the air chute, cools the lower portions of the icebox, and returns to the top of the box to repeat the cycle again and again. The nail holes should be filled with putty and the inside and outside of the | box given several coats of white enamel. | The shelves need not be enameled, as they | are easier washed without. F ANY difficulty is experienced in | obtaining materials for building the | icebox, such as cork, insulating paper, or door packing, the Information De- | of POPULAR SCIENCE | partment MONTHLY will be glad to supply the names of manufacturers, if you will send a self-addressed envelope and state specifically what you wish to know. NEGA Rots Acne ee ee ee a a — FP wetweho et

Page 109

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HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

Home Workshop Chemistry Simple Formulas that

Abteeres there are many ways to remove some stains, other stains never can be removed wholly. Will Save Time | and Money | | | | | | Old paints and varnishes on wood often | are troublesome. Liquids alone will not take them off; burning is not the best | policy; scraping too often injures the work. A combination of liquid softeners and scraping usually must be resorted to. The following mixture, although not | pleasant to work with, usually will do the trick: Mix 14 pt. of waterglass with 2 oz.

Removing the finish from metal with equal quantities of ammonia and alcohol of ammonia. Dissolve a teaspoon of lye, which is also called ‘‘sodium hydroxid,”’ in an ounce of water and mix the two solu- | tions. Lye may be obtained at the gro- | cery in cardboard containers. When | opened, it should be placed in a glass bottle and corked tightly; otherwise it will dissolve in the air. Brush the mixture on the paint or varnish and let it remain until the coating is soft; then scrape it off. For delicate work, scrape with wood shavings. Stains on woodwork are very resistant. While they often can be taken out par- tially by bleaching, the bleaching process is applied only on work that is stained in patches. One method is to use 3 oz. of oxalic acid crystals (about 25 cents’ worth) in 1 qt. of warm water. This will bleach many stains and remove _ ink | marks from any surface, as well as rust stains. Metals from which the varnish has been scraped or chipped in places, can be cleaned by dipping into a solution made by pouring ammonia (strong Treating varnish for ammonia water) match scratches into the same quantity of denatured alcohol. If the article is too large to be dipped, apply the solution with a soft brush. Keep the solu- tion away from flames and work out of doors, if possible, or at least near an open Window. See that the articles remain moist until the varnish has softened; then wipe the metal clean with a rag. The following is a short list of stains (Continued on page 108)

| | | | | | |

ATENTS Seventy-eight Years of Practice HE firm of Munn & Company filed its first application for a patent in 1846, and for seventy-eight years has endeavored to keep pace with the inventive genius of the United States. An experience of many years is at your disposal. If you have an invention which you wish to patent, send your sketches or model together with a description of your device, explaining its operation, and you will receive prompt, courteous attention. Write for our Handbook on PATENTS A full and complete booklet on Patents, Designs, Trade-Marks, Foreign Patents, Copyrights, Labels and Patent Office Practice with an explanation about our methods, terms, etc. All communications strictly confidential Keep in touch with theinventions of the world by reading SCIENTIFIC AMERICAN The MONTHLY MAGAZINE with a special appeal to every man of inventive genius. Recent rulings of the Patent Office, descriptions of the latest patented inventions, legislation and court decisions affecting patents, are noted in this authoritative publication, MUNN & COMPANY Patent Attorneys 618 Woolworth Building, New York City Scientific American Bldg., Washington, D. C. Tower Building, Chicago, III. Hobart Bldg., 582 Market St., San Francisco, Cal. Van Nuys Building, Los Angeles, Cal.

NVENTORS your ‘ibe YOUR IDEAS Send for our Guide Book, HOW TO GET A PATENT, and Evidence of Invention Blank, sent Free on request. Tells our terms, methods, etc. Send model or sketch and description of your invention for our Examinae p= - 2+ +--+ <n 0-2 nen oe enee ene tion and Instructions without

i charge. RAMEN a ccaiceia elo Ss) eserew erasieleks . <watsaeeee CE ssc niiasrchennexd: aod see Hig RANDOLPH & CO. | Dept. 130, Washington, D.C. ' CR fre ee: [SPMEBS (o: edckesest

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= te - - me | | } } ‘Another $50 Raise!” “Why, that’s the third increase I’ve had in a year! It just shows what spe- cial training will do for a man.” Every mail brings letters from some of the two million students of the International Correspondence Schools, telling of advancements and increased salaries won through spare time study. How much longer are‘you going to wait before taking the step that is bound to bring you more money? Isn’t it bet- ter to start right now than to wait for years and then realize what the delay has cost you? Once hour after supper each night spent with the I. C.S. in the quiet of your own home will prepare you for the position you want in the work you like best. Yes, it will! Put it up to us to prove howand why. Without cost, without obligation, just mark and mail this coupon, ——E oe oe oe Ga ~ INTERNATIONAL CORRESPONDENCE. SCHOOLS — Box 7695-C, Scranton, Penna. Without cost or obligation on my part, please tell me how I can qualify for the position or in the subject before which I have marked an X BUSINESS TRAINING COURSES Business Management 1 Salesmanship Industrial Mana ent C] Advertising Personnel Organization LJ Better Letters ‘} Traffic Management LJ Show Card Lettering -} Business Law (_] Stenography and Typing - Banking and B: in _, (_] Business English Accountancy (i ling C.P.A.) (J Civil Service J Nicholson Cos t = ‘ ie (] Railway Mail Clerk -] Bookkeeping | Common School Subjects ] Private Secretary CJ High School Subjects (J Spanish O French CJ Glustrating TECHNICAL AND INDUSTRIAL COURSES (1) Electrical Engineering (0 Architect |) Electric Lighting ( Architects’ Blue Prints [ }Mechanical Engineer (Cj Contractor and Bui Me ler [ } Mechanical Draftsman ( Architectural Draft [} Machine Shop Practice (J Concrete Builder []Railroad Positions Oo Structural Engineer (jG as Engine Operating ] Chemistry (1) Pharmacy (_) Civil Engineer Automobile Work Surveying and Mapping (J Airplane Engines Metallurgy O) Mining (J Agriculture and Poultry Steam Engineering 0 Radio B Mathematics IID ix cnnsénn:sacnscnccnsccnsséecncnchrscinncseseocnsetcerasesscbetopenescesenesnseceses Street 3-6°24 GSA cabaavaniel unsecipeiencees SURED cacessununcsenssccwneses sasheonss SRNR 6 wissen cpotesaneauscoeuspkewasvapes (YER CRET EEE SS ROC OA SOROS S RTP ETN EE Persons resid rein Ce should send this coupon to the International (€ Darndest Schools Canadian, Limited, Mens real, Canada HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY | | stencil ink, thick rubber stamp ink, or a | | little printer’s | drier such as is used in paint. | Typewriter Stencil Makes a | Self-Inking ‘“‘Rubber” Stamp | CLEAR-CUT, sharp, and _ neat- looking stamp can be made in a few | minutes with the aid of a typewriter and a small piece of commercial stencil paper. First obtain an old rubber stamp and peel | off the rubber strip with the lettering from the cushion of sponge rubber under- neath. Cut a piece of napped cloth the exact size of the sponge rubber and lay it upon the latter with the napped surface up. Ink the cloth with regular typewriter | UBBER BAND-~ Typewriter stencil paper over layer of inked cloth gives clear-cut impressions ink thinned with a good | Next cut a piece of typewriter stencil paper, obtainable at any large stationery store, to a size 2 in. longer and wider than the napped cloth. Typewrite or print with a stylus the required wording on the stencil paper and lay it, readable side | down, on the inked cloth. Fold the pro- jecting edges of the stencil paper over against the wooden body of the stamp and hold in place with a rubber band snapped around the whole. Use the stamp as you would a regular rubberstamp. You will not need to re-ink it for a day with ordinary use, and a new imprint-can be made at any time. Home Workshop Chemistry (Continued from page 107) and the chemicals that will remove them: Paint—turpentine or benzol. Grass stains—alcohol or ammonia. Tar or wagon grease—turpentine or benzine. Ink—solution of oxalic acid or lemon juice. If the ink does not — ain iron, try dilute acetic acid. Green ink is bleached by ammonia. Many aniline inks are removed with alcohol and nearly all of them with a solution of chlorinated lime followed with a wash of dilute acetic acid. Rust—with oxalic acid. Mildew—with sour or sweet milk. after which the article or materi ial i is soaked overnight. The unsightly marks and streaks left after striking matches on painted surfaces are difficult to remove, especially if they are old. The annoying habit of striking matches on finished surfaces can be pre- vt vented by rubbing the surface vigorously with a piece of flannel bearing a very little vaseline. The rubbing must be applied with pressure, been rubbed in, take a dry piece of flannel | and again rub the surface thoroughly. Matches can not be struck on this surface. Fat spots on wool are cleaned with gaso- | Try any of these | first; if the spot is not removed, try a dif- | line, ether, or benzine. ferent solvent. Fabrics of delicate color that have been stained with coffee or chocolate are cleaned readily by applying a drop or so of glycerin. Let it standa minute or so, and then wash off with | water or alcohol. and the vaseline worked | well into the paint. When the vaseline has | Course for men of ambi. ae . limited time. Electrica men_ trained, Condensed course in ‘eet and Practical Elec. trical 2 including Engineerin the close- lyrelated subjects of Mathematics and Mechanical Drawing taught by experts. Students construct motors, install wiring, test electrical machinery. Course complete In One Year Established in 1893. Prepare for your profession the most interesting city in the world. Free cat:log. BLISS ELECTRICAL SCHOOL 102 Takoma Ave. Washington, D, c, 21 Jewels Nothing aed then 21 Ruby and Sapphire sewel is good eno; ‘or Burlington masterpiec Quality and Style justed to the second—temperature— 25 year Gold ' Strate Cese, “in 100 des! Sd down, y payments. 9th Street le _Bepte8- +136 Chicago. Minois | Beautiful ee Instead of Your OLD FORD Choice of Four Colors; Fiat — Z \ Bullet Nose Ra \ iator Shell. Sead ; + for 1924 Free Cat- alos of New Auto Acces’, Bodies and Speed Equipment. Direct from Factory, AMERICAN TOP AND BODY CO., Beech Street DELPHI. IND, Squab Book FREE Squabs selling at highest prices ever known. Greatest market for 20 years. Make money breeding them. Raised in one month. We ship everywhere our famous breeding stock and supplies. Established 23 years, Write now for big illustrated free book, How to Make Money Breeding Squabs, PLYMOUTH ROCK SQUAB CO. 616 H St., Melrose Highlands, Mass. send for FREE GOOK roo ee Drive This Every a. pe vcs have it. Inter- esting angling hints. Tells what baits to use for every kind of fishing. Postal gets it! SOUTH BEND BAIT CO. 14562 Migh st, South Bend, ind «REGISTERED PATENT ATTORNEY SINCE 1905, W LOVETT Stcunity 6.06 LYNN MASS SENDO FOR FREE BOOKLET WAKE INTO your FORD fis SPORT CAR ONLY Other types down to $3.50. Famous sure fit, Aarne $ 40 size patterns and picture instructions show how, We easily convert your Ford into this fast, saucy hundreds ay aed Cin a few 8 worth of material from the’ cee store. No eed to lay up e Keen, Classy Up-to-the-Minute rides wonderfully easy. delivery; ecg nd 5: — I d. Bailt | Order NOW while gael make om, e) coin for tilustrated 08 x gor ee Wie +R thy porate of Sport Bodies, who derive larg: KUEMPEL Co. 531 Kuempel Bida., Guttenberg, fowa est profits know and heed certain INVENTORS 2632" facts before applying for Patents. Our book Patent-Sense gives those facts; sent free. Write LACEY & LACEY, 648 F St., Washington, D. C., Established 1869. Protect your tools from theft. Write any name, y design on tools and metal with electricity ai writing on paper with or penc omplete outfit 50, ae anywhere. Interest- | ing descriptive circulars free. Write | to-day. Agents wanted. Arkograf Pen Co., 1171-A East Stark St., Portiand, Oregon a

Page 111

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can be bent and will remain in shape if heated over a candle. might be attached with a string so that it | will float above the imitation balloons. NO.6 REED

Balloon Vender Kite (Continued from page 73)

A toy gas balloon A good grade of tissue paper is perhaps the best all-around covering for kites. The greatest objection to tissue paper is that it slits badly. increases to a calamity. A small hole generally A good way to REINFORCED

How the kite is made, method of reinforcing tissue paper with glued threads, and photographs of framework and finished kite offset this is to lay glued threads diagon- ally across the paper in two directions about 3 in. apart. The thread is coated by running it through a puddle of glue. Then lay it down on the paper. For large covers, a network of string at the | back of the paper, not glued, helps to sup- | port the paper when pressed hard by the breeze. _ First cover the entire kite with white or light blue or gray paper. It is best to paste the sheets together with not more than 14-in. laps. After enough pieces have (Continued on page 110)

PATENT NOTICE Cunningham Tubes are covered by patents dated 2-18-08, 2-18-12, 12-30- 13, 10-23-17, 10-23-17, and others issued and pending. Licensed only for amateur, experiment- } al and_ entertainment use in radio communi- cation. Any other use will be an

infringement. nace Cunningham 40-page Data book fully ex- Prices on Cunningham radio tunes || plaining care and operation of Radio Tubes Now in Effect now available by sending 10c in stamps to Oe ae cee San Francisco office. C-301A x4 Volts 1-4 Am pere filament -_- $5.00 C-299—3 Volts .06 amp. (0 ° Dry Battery Det. and ° fy < a ee - .. $5.00 C-300—5 Volts Gas Con- tent Detector. _ __ .$5.00 C-11—1.1 Volts .25 amp. Branch HOME OFFICE _ Branch Dry Battery Det. and Office Office _ Amp. Special Base _ . $5.00 182 Second Street C-12—Similar to C-11 with Chicago San Francisco New York standard base -$5.00 UI) HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY RADIO The Standard Tube of the World for RADIO RECEPTION The Radio Tube, through radio telephony and public broadcasting, has been largely instrumental in establishing the new and increased interest to humanity attuned to Radio. This tremendous progress in Radio has brought about the cevelopment of radio receiving sets resulting in clearer reception of voice and music throughout the broadcast world. Cunningham Radio Tubes are the product of years of research and experimental work by the en- gineers of that great scientific organization, the Research Lab- oratory of the General Electric Company. There is a Cunningham Radio Tube designed to meet the re- quirements of your particular set —ask your dealer.

PERSONAL STATIONERY 200 Sheets and $4.00 100 ENVELOPES or Printed With Your Name and Address Clear, white bond paper, with envelopes to match. Your name and address printed in beautiful, rich blue ink, on both paper and envelopes, and sent to you postpaid, for only $1.00. (West of Denver and outside of U. S. $1.10.) If inconvenient to send _ the money, we will ship C. O. D. Write name and address plainly. Money returned if you are not more than satisfied. Order today! ELITE STATIONERY CO., 5085 Main St, Smethport Pa

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At last the high powered micro- scope is within the reach of all who § 50 re cere objects that are invisible to the for naked eye. / : Complete Any amateur can immediately bacteria in dirty water. No technical training re- quired yet hundreds of scientists and teachers are using this in- tific. Gives enormous magnifica- tion and perfect definition. Order direct from this Order Today anteed. If, however, you desire more information before purchasing, we will gladly send free descriptive catalog. wish to study, observe and experi- start using his Ultralens to examine Outfit Prepaid strument today. It is at once advertisement and get SCIENTIFIC APPARATUS CORP.

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Page 112

EARLE E. LIEDERMAN The Muscle Builder A Slap in in the Face With a Cream Puff is not a man’s way of fighting. Neither can you do a man’s job with balls of mush on your arms where muscles ought to be. How long are you going to drag along this way? Don't try to kid yourself by saying: “Oh, I'll start regular exercise next week.’’ I know a lot of fellows who kept doing that until—Zowite—it was too late. They couldn't make a come-back no matter how they tried. THIS IS A BIG DAY FOR YOU Don't put this off another second. If you want to make the best of your life, you'll have to start rig zht now. Come on, let's go—vyou and me—and you're going to bless the day you read this message. I'm going to make you work—you can bet your old _ shirt on that. But you'll thank me for it, ’cause—oh boy! -what a different looking chap you're going to be. Just for a starter I'm going to put one full inch on those arms of yours in exactly 30 days—and two inches on ve yur che st in the same length of time. But that’s nothing. Then comes the real works. I'm going to build out that neck of yours and put a pair of shoulders on you that will bulge right out of your old coat sleeves. I'm going to fill out your chest with a perfect pair of lungs that will pump real oxygen into your blood, shooting a thrill over your entire body and sending a quiver up your old spinal column. I'm going to put a ripple of muscle up and down your stomach instead of that roll of fat that is now hanging over your belt line. And while I'm doing this, I am also going to build muscle in and around every vital organ. You will have a spring to your step and a flash to your eye. In fact, you will say to yourself: What a terrible oil-can I’ was turning out to be; why didn’t I start this long ago?” LET’S GO! time over the se things. yu want strength. fou want /Irfe. What I can give you— it’s yours for the asking. try to kid you on with a lot of idle promises. I guarantee these things. You don’t take any chance with me. Come on now and get on the job. Be the man you have always wanted to be. Send for My New 64-Page Book “MUSCULAR DEVELOPMENT” it is FREE It contains forty-three full-page photographs of Why waste muscle. Y« you want, I don’t You want myself and some of the many prize-winning pupils I have trained. Some of these came to me as pitiful weaklings, imploring me to help them. Look them over now and you will marvel at their present phy- siques. This book will prove an impetus and a real inspiration to you. It will thrill you through and through. All I as sk is 10 cents to cover the cost of wrapping and mailing and it is yours to keep. This will not obligate you at all, but for the sake of your future health and happiness, do not put it off. Send today—right now before you turn this page. EARLE E. LIEDERMAN Dept. 1307, 305 Broadway, New York City — mee eee eee ee ee ee ee ee oe EARLE E. LIEDERMAN Dept. 1307, 305 Broadway, New York City Dear Sir: I enclose herewith 10c for which you are to send me, without obligation on my part whatever. a copy of your latest book ‘‘Muscular Development” please write or print plainly). HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

Balloon-Vender Kite (Continued from page 109) been pasted together, lay the paper on the floor and place the framework face down, on top. Cut about 34 in. to the outside of the frame and string. Paste the outside flaps, turn over edges, and press them down. with scissors. On the curves, slit into the flaps While the kite is still on the floor or table, some strips might be pasted over the framework at the back, thus reinforec- ing the cover. Some of the balloons will not be full circles, but just the portion that shows. BALLOON KITE UMBRELLA KITE

BODY PORTION \. OF PAPER TUBE \\

LEGS OF PAPER TUB OPTIONAL The construction of the vender and sug- gestion for an alternative umbrella kite The strings are represented by he

E avy black strips, rather out of proportion. A three-string bridle is best for balloon kite. string attached about halfway from the Such a bridle can have a the spine to the outside point on either side, and another string attached to the bot of the spine. paper about the hole where the strin the bridle goes through the cover. kite line strings of the bridle come together. tom Use little reinforcements of g of The is attached where the three The balloon vender serves as a balancer and is hollow. ——the breeze passes into his body thro There is no top to his head ugh this opening; it is his breathing apparatus. A series of reed rings down through the body will serve to keep the gentleman from total collapse. The arms and need not be stayed in such manner. bottom of the legs are open to allow legs The the breeze to pass through. The arms extend above the head and cling to the cord hanging below the kite. have small rings in his legs, but it is The man may not necessary to shape the hands or feet. The clothes should be of dark paper the tace white, pink or yellow, with b markings for eyes, nose, and mouth. B tissue can be used for such markings. and lack lack The man may be made of cardboard, but will not be as interesting as if hollow. He should hang 3 ft. below the kite, if he is not sufficient balance, some fri and tassels can be added. and nges The same kind of framework and the same hanging figure may be used the umbrella kite shown above. with

Smoker’s Teeth | Bleached White + ® in 3 Minutes | : New Safe Method Removes Stains— Makes Teeth Flashing White No matter how much you smoke—no matter how stained your teeth may be—a new safe treatment has been perfected by prominent dentists, which g bleaches away tobacco and other stains, leaving teeth wonderfully clear and white. This new dis- i covery is called Bleachodent Combination. Con- sists of a mild, harmless liquid which softens and ; breaks up the stains, and a new kind of paste. The paste not only quickly and gently removes the soft- ened stains—but used daily prevents the formation seen okt = ek (a <fpspi ec AD —_ ~~ oe ad or of new ones. You'll be amazed to see how quickly dark teeth are made flashing white and lustrous. Bleachodent Combination is safe and harmless to use. No effect on enamel as its mild ingredients are especially designed to act only on surface stains —not on enamel itself. Originally prepared for whitening children’s soft, sensitive teeth which are so easily injured by harsh, gritty pastes and pow- ders. Get Bleachodent Combination today. Costs only a few cents. Distributed by Bleachodent a te ae Dental Laboratories and sold by drug and depart- ment stores everywhere. BRiceS ote

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FREE BARGAIN BOOK of the best Auto Supplies if you knew our sources and names of manufacturers, Special made Bodies—Tires— ;ODI ES Tubes — Batteries— Spotlights 54ND book exactly illustrate s in colors : thousands of bargains. What- backed by our Legal, Binding Guarantee of absolute satisfaction. Thousands of pleased customers every- Send Postal Card for ~ BIG FREE Book. Be sure to ask for os Special V 6S N. Peoria Street Chicago, I. An automobile goes 27 miles on air by using an 5S minutes. The automobile was only making 30 able invention was installed, it made better than 57. The inventor, Mr. J. A. Stransky, 785 Eleventh is willing to send a sample at his own risk. Write him today.—Adv. Our net price list. Full line of SEND FOR OUR BIG made! You'd be surprised EVERYTHING =*—} —Bumpers—tTools, etc. This ever you need or want in Equipment. Ev ery article where. Get on the inside of this Price-Saving business. EW YORK ore & RADIO SUPPLY Co. automatic device which was installed in less than miles on a gallon of gasoline but after this remark- Street, Pukwana, South Dakota, wants agents and SEND FQR THE Repeneny een. CATALOG auto bodies

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Page 113

Ow ent lich ‘ing dis- on- and The of t- tion ckly ous. s to ents ains for | are OW- ‘osts dent yart- i LS wel 8: AND UP rticle solute very- iness. ire to ing an ; than ing 30 mark- an 57. venth ts and Write ALOG ‘ice list. line of » bodies accesso- for Fords Diag ae’ yt ‘ F & Fy L Good Geie— Wherever You Go! Sixty miles on the speedometer— twelve noon by the clock—a quiet, shady grove by the roadside —a lunch basket packed with good things to eat—and five hungry people ready to sit down to a feast at nature’s table. That’s the time for a little music from the pocket orchestra—a few lively selections on a Hohner Harmonica— The World’s Best There’s nothing like good music for happiness; and there’s nothing like a Hohner for good music. Hohner Harmonicasare truein tone, accurate in pitch and perfect in workmanship. Anyone can learn to play real music quickly. Get a Hohner Harmonica today and play it tonight. 50¢ up at all dealers. Ask for the Free Instruction Book. If your dealer is out of copies, write M. Hohner, Inc., Dept. 182, New York City. OHNER VW YS Rees os SOLDERALL. SOLDERS ALL = JOINTS PER 4 A APPROVED BY THE NATIONAL BOARD of FIRE UNDERWRITERS ere, Kh, AT ALL I SAAR arn at apa eo hd to gee birds, ani. iS; make rugs an robes.” #, game ne Tessons. ‘Easily and caicie ned by men, pore an . "o ae ‘ rite for Free Taxider — Telis ail gbout te ver ‘apper an Nature lover should know this wcaidectal fascinating art. Save your tropnies. Big meeite. jucces® guaranteed. rad- See -¢= DURHAM | #5 Variable Grid Leak At dealers, or po Ss) id Durham & Co., 1936 = St., Phila. 5, | Nort of Tas Sinn, haggle Free Bost. CONIAANTNN NOH NNO Marking Device for Laying Out Spiral Flower Beds STERS and zenias, when _trans- planted in beds laid out spirally, present a more artistic appearance than when planted in straight lines. The spirals may be marked quickly with the homemade device illustrated. In the bottom of an inverted barrel a hole is made through which a pipe is passed and driven into the ground. The barrel is fixed to the pipe so that it is held The marker is drawn con- stantly nearer to the barrel stationary. A ‘‘two by four” is used as a beam upon which a wooden marker is | mounted in such a manner as to be free to slide. One end of a length of clothes-line is fastened to the barrel and the other end is attached to the sliding marker. To operate the device, the beam and marker are turned about the barrel. This causes the line to wind up as on a drum, thus drawing the sliding marker toward | the center. The resulting spiral trough made by the pointed marker serves to guide the gardener when setting out the plants.—C. M. WutLcox, Torrington, Conn. Two Wooden Braces Hold the Ice-Cream Freezer Firmly HE usual difficulty of trying to hold an ice-cream freezer while churning may be overcome quite easily by bracing the machine as illustrated. Place the freezer on a bench of con- venient height in the cellar and measure the distance from the metal cross piece to How the freezer is braced = =] the floor beams above. 3 in. boards cut to this length and saw a V in one end of each. Locate each V over the metal cross piece and hammer the upper end of each brace under the rafter Obtain two 34 by above. If the brace is a bit too short, a shingle can be wedged between it and the rafter.—D. D. SIMONDS. HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 111 When did you find your ideal tobacco? Sooner or later we all choose the perfect smoke partner— - Here is an interesting letter from Mr. Charles H. Bishop of Chicago. It con- firms the truth of an old proverb— “better late than never.” We hope that reading it may show some misguided pipe smoker the path to smoke satisfaction. Chicago, II]. Larus & Bro. Co., Richmond, Va. Gentlemen: I am glad to write you th at I have con- vinced a man of fifty years’ smoking ex- perience that “it’s never too late to change.’ The new convert to Edge- worth is my father-in-law, now approach- ing seventy. Year after year at Christ- mas [ had bought him, among. other things, a large jar of tobacco; but until this year my heart was never wholly in the selection. But this Christmas I purchased Edge- worth, which he had tried after constant urging on my part—and he’s satisfied! Yours sincerely, Charles H. Bishop. We are glad Mr. Bishop induced his father-in-law to try Edgeworth, and we hope that the old gentleman will derive much pleasure and comfort from his pipe for many years to come. But it seems to us a shame that he didn’t become ac-— quainted with Edge- worth many years ago. We try to make Edgeworth a tobacco that most men will like regardless of age, and the evidence would seem to show that we do. Cf course, we don’t hope to suit every man’s taste, but a great many smokers have found Edgeworth “just right.” Why net let us send you a free sample of Edgeworth? Maybe it’s just the smoke you've been looking for. Your name and address on a postal to Larus & Brother Company, 59 South 21st Street, Richmond, Va., will bring you generous samples of Edgeworth with our compliments. If you care to include your dealer’s name and whereabouts we will appreciate the courtesy. To Retail Tobacco Merchants: If your jobber cannot supply you with Edge- worth, Larus & Brother Company will gladly send you prepaid by parcel post a one- or two-dozen carton of any size of Edgeworth Plug Slice or Ready-Rubbed for the same price you would pay the jobber.

Page 114

112 Your Choice 75c a Week | Muhave: cut the price one-half No matter what your occupation, one of the home study sets listed below will quickly fit you for a better job and bigger pay. Any set you select will be sent for seven days’ examination, and if you decide to buy you may pay the rock bottom price at the rate of only 75c a week. But you must act now! The rising cost of paper and binding materials won't permit us to continue the present low prices much longer. These books are the work of recognized author- ities. They are written in plain, easily understood language, by recognized authorities, and contain hundre ds of photographs, diagrams, tables, etc., that make difficult points as simple as A-B-C Hand- somely and durably bound in half or full morocco leather (except as noted), and stamped in gold. Pay-Raising Books At Greatly Reduced Prices Business Management, 8 vols., 2500 pages 1000 pictures. Was $52.50.. - Now $29.80 Carpentry and Contracting, | 5 " volumes, 2138 pages, 1000 pictures. Was $37.50,Now 19.80 Civil Engineering, 9 volumes, 3900 pages, 3000 pictures. Was $67.50 Now .80 Electrical Engineering, 8 volumes, 3800 pages, 2600 pictures. Was $60.00 .... Now Automobile Engineering, 6 volumes, 2600 pages, 2000 pictures. Was $45.00 ....Now 21.80 Machine Shop Practice, 6 volumes, 2300 pages, 2500 pictures. Was $45.00 .... Now -80 Steam and Gas Engineering, 7 volumes 3300 pages, 2500 pictures. Was $52.50 .Now 24.80 Law and Practice = reading course), 13 volumes, 6000 pages, illustrate‘. Was See eee a ee Now 80 Fire Prevention and Insurance, 4 vols., 1500 pages, 600 pictures. Was $30.00, Now 14.80 Telephony and Telegraphy, 4 volumes, 1728 pages, 2000 pictures. Was $30.00 Now 14.80 Sanitation, Heating and Ventilating, 4 volumes, 1454 pages, 1400 pictures. Was $30.00. ......... N 14.80 Drawing, 4 volume s, 1578 pages, 1000 pic- tures, blue prints, etc. Was $30.00. .-Now 14.80 Send No Money Shipped for 7 days’ 7 Yes, we'll gladly ship any set right to your home or office upon your si “4 <3 request. Pay only ship- ping charges when the books arrive. Don't send a penny until after you have used them seven days, then remit only $2.80 or return them at our expense. Pay balance at the rate of $3.00 a month—75e a week. Act now—while these ndid books are being offered at 20% to 50% less than regular prices. This offer is open fo eve ry person within the boundaries of the U. S. and Canada. Grasp your opportunity fill in and mail the coupon now. American Technical Society, Dept. XB-20, Chicago American Technical Society, Dent. XB-20, Chicago, U. S. A i

Please send me sct | t { for 7 days’ examination, . shipping charges collex [ will examine the books thoroughly and, if satis ied, | U will send $2.80 within 7 days and $3.00 each month, q until I have paid the special price . er If I decide not to keep the books, I will notify you at | | once and hold them subiect to your order. Title not g to pass to me until the set is fully paid for.

I | Name 1 Address _ Employed’ by ee ae a oe oe ee ee ee oe ol POPULAR SCIENCE MONTHLY

Radio’s Part in Politics (Continued from page 23) himself an orator of note, suggested re- cently that radio will help restore oratory, since the public will demand facts and reasons, well and briefly stated, will toler- ate only real eloquence, and will reject in disgust banal sentiment and wordy emptiness. A phase of the subject that I mentioned above was commented on recently by Brigadier-General James Guthrie Har- bord, president of the Radio Corporation of America, as follows: “The fact that candidates are described and written up by the newspapers and magazines is not enough to satisfy the average voter. He wants to get at the sincerity and motives of the candidates and this comes only through contact. The glimpse of a man on the back plat- form of a train leaves an impression that no amount of writing will do. That per- sonal touch is what men in public life have always sought, and they can establish that contact now to all parts of the country by radio. Radio will elect the next President.” O FAR, speakers on political topics have, for the most part, confined their activities to short discussions be- tween entertainment acts provided by the broadcasting companies. The radio spellbinder may have to follow the lead of the national advertisers and provide a band or a jazz orchestra to offer enter- tainment as an inducement to listeners-in to hear him. This is no new thing in spellbinding. Senator James A. Reed of Missouri, an old-style, whirlwind spellbinder, engaged a small traveling circus to campaign with him when he last ran for the Senate. He set up his circus tent at the country crossroads, and after the band had at- tracted the farmers, he cut loose with politics. The radio campaigner might improve on this. The evening of politics might include music, comedy, and stunts from a good vaudeville show. For serious political debate on topics in which the public is interested, the radio is made to order. It is interesting to reflect how many people might have heard the famous Lincoln-Douglas debates, had radio broadcasting been in use then. In those days a meeting hall that held 2500 people was monumental. Probably not more than 15,000 people heard Lineoln and Douglas in their whole series of seven debates over the state of Illinois. The course of history might have been changed had the whole country heard them by radio. UBLICISTS are greatly concerned as to how the Democrats and the Republicans will divide up the ether. They are worrying lest one or the other party monopolize radio broadcasting, or that rival spellbinders will spoil each other’s speeches by talking at the same time. Radio engineers say these dangers do not exist, for several reasons. In the first place, the expense of broad- casting prevents a monopoly. Neither party has a campaign chest that will per- mit it. Second, radio fans would not stand for it, and broadcasting companies are extremely responsive to the wishes of the listeners-in. The broadcasting companies, through their associations, are dividing the time among themselves, or are using different wave-lengths without interfering with each other. Finally, there is the authority of the government, acting through the Chief Radio Inspector, to keep order in the ether. Secretary Hoover, who is responsible for the ad- ministration of radio regulations, has declared it inconceivable that any single group or person shall ever have the right to determine what communication may be made by radio. “Radio is a public concern,” he states, “fmpressed with public trust, and to be considered primarily from the standpoint of public interest.”’ So there seems little doubt that the radio spellbinder, if he has something to offer that radio fans care to listen to, will have plenty of opportunity to have his say by radio. It is up to him. All signs point to radio’s exerting a most profound influence in the presidential campaign of this year; and this year, remember, is only the beginning —an experiment even. Wider use of radio for political purposes can be pre- dicted with certainty for the future. Political leaders will become more and more expert in its employment as time goes on. Skill in radio oratory eventually will become a necessary part of the equipment of the man in public life. Each year there will be more radio receivers; hence, a larger audience for the radio spellbinder. And who dares say that through radio, through the better understanding of politics and_ political issues that it will bring to the average man, some day may not be realized the long existing dream of patriots—a perfect government?

Hay Fever Pollen Drifts to Mountain Tops F YOU suffer from hay fever, you haven’t much chance of escaping it, even by fleeing to the top of a barren mountain, according to an announcement made recently by Dr. William Scheppe- grell, of New Orleans. Hay fever is caused by the irritation of sensitive membranes in the breathing ap- paratus from the pollen of certain plants. If hay fever sufferers can keep away from this pollen, they are safe; 15,000 feet! When the air cools, the pollen descends, a fact that explains why hay fever sufferers find their distress aggra- vated at night, in the fall, or on unseason- ably cold days. Pollen was found by Doctor Scheppegrell as far as 10 miles from its source, from which he concludes that local campaigns to stamp out rag- weed and other pollen-producing plants are of little benefit unless extended over wide territory.

but Doctor | Scheppegrell, flying in an airplane, has | discovered that clouds of pollen are car- | ried by the wind to the height even of | OR a ‘gm~@DoOnD rt Sal Oc OES sD A TReaeaA oO Bo

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l not yanies vishes isting is, are es, or thout nally, ment, ector, retary | e ad- , has single right lay be states, to be lpoint it the ing to 0, will ve his erting 1 the - and inning ise of e pre- uture. e and ; time tually if the radio ‘or the Ss say better litical verage 2d the yerfect s to , you ng it, barren ement leppe- ion of ng ap- ylants. y from Joctor e, has | e Ccar- ven of pollen y hay aggra- eason- nd by miles cludes it rag- plants d over USE-1IS THE TEST Build Your Radio Set With Kellogg Guaranteed Parts 43 Plate— 3 Plate Vernier HE Kellogg variable conden- ser is built to give perfect service indefinitely. The heavy aluminum plates cannot touch. Large bear- ings assure smooth operation and mimimum wear. The size and type of plate furnish greatest selec- tivity and volume. End pieces are Bakelite. Have your dealer show you our complete line. Buy Kel- logg Parts and you know your set will be good. If your dealer does not handle Kellogg communicate drect with us. 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Dept. 80.47 Dayton, Ohio Chevrolet .32 mi. Maxwil (25) .30 mi’ Nash 6..... 23 mi. POPULAR SCIENCE MONTHLY The Greatest Spectacle (Continued from page 29) of all the others, an assumption amply warranted by facts regarding the stars gained through the use of a wonderful instrument called the ‘“‘spectroscope.”’ This instrument permits an accurate chemical analysis of a star to be made as readily as the analysis of a lump of earth could be made in a laboratory. Most people probably know that ordinary sunlight passing through a prism splits up into seven components of different colors—violet, indigo, blue, green, yellow, orange and red. These seven colors are known as the solar spectrum. It has been found that the light given off by different substances in burning results in spectra that vary greatly, a fact that you can easily appreci- ate, if you have observed how various | substances burn with flames of different colors. By observation and experiment science | has succeeded in classifying the various | chemical elements on earth according to the colors of the light with which they burn. Hence, by permitting the light from various heavenly bodies to pass through the spectroscope, astronomers can make chemical analyses of those bodies just as readily as if they had samples of them in test tubes. HE most surprising fact developed by chemical analysis of the heavens is that apparently all matter in the sun and stars and throughout the expanses of space is made up of the same 92 chemical elements that compose our earth. In fact, certain chemical elements were dis- covered in the sun by means of the spec- troscope before they were found on earth. Helium, the gas now used to inflate air- ships, is a conspicuous example. At least one element in the corona or fiery halo of the sun has not yet been discovered on earth. Having found out so much about the individual constituents of stars so far away that the unaided eye cannot discern them, it would seem that astronomers surely must have discovered just what sort of a place is this universe of which our solar system is so inconsequential a part. Well, not exactly, although they have formed a theory more astounding possibly, than exact knowledge would be. Modern astronomers believe that the universe is without limits in its larger aspect, and theoretically without limits in its smaller. Beginning with the elec- tron, which is the smallest particle of matter we recognize, we progress to atoms, molecules, worlds, solar systems, galaxies, supergalaxies—on and on, never reaching the end. Each of these units is infinitesi- mal compared with the next larger unit, and each group of units is infinite in number. Of course, no one can offer absolute proof of such atheory. In all probability no one ever will be able to; yet it presents a picture more convincing than that of a universe that progresses so far, then stops —even though between the starting place and the end stretch countless billions of light-years. Astronomers, however, are able to give (Continued on page 114) ] lcanize - its the Easiest Way When you go on your vacation trip this summer don’t make the same mis- take you did last year. Instead of spending a lot of money for extra tires and inner tubes—get a handy Shaler 5-Minute Vulcanizer for only $1.50. Then when you get a puncture on the road you can vulcanize it quickly —for only a few cents. It’s quicker than changing tubes and much better than sticking on patches that soon weaken and come loose. More than two million motorists carry the Shaler for emergency use. It’s the quickest, as well as the easiest way, to mend punctures—and vul- canized repairs last. HALE. 5-Minute Vulcanizer is very simple and easy to use. A special Patch-&-Heat Unit is used for each repair. Each unit consists of a metal pan containing solid fuel and has a patch of raw rubber attached underneath. Simply clamp a Unit over the puncture and light the fuel. After five minutes take off the pan and throwitaway. That’sall. The tube is ready to use—it’s vulcanized. Costs only $1.50 Slightly higher in Canada and Far West Complete outfit includes nickel plated vulcanizer and 12 Patch-&- Heat Units—in a small_package, ready for instant use. Wherever auto accessories are sold you can buy the Shaler. Get one tcday. C. A. SHALER CO. 2103 Fourth St. Waupun, Wis.

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POPULAR SCIENCE MONTHLY

| | { i The Greatest Spectacle (Continued from page 113) a more or less definite picture of the galaxy, or collection, of stars, to one of which our sun and its planets belong. Our galaxy is known as the “Milky Way.” Though the nearest star in the Milky Way is so far away from us that on a telescopic photograph it appears as only one of thousands of tiny white dots, nevertheless it is comparatively close to us when we know that if a similar photograph were taken from some earth far out on the other side of the universe, our sun would appear on it only as another infinitesimal speck in that confusion of dots. Photographs of the Milky Way show that the stars are distributed through it in widely varying quantities. One area may have 100,000, while in another there may be only a few hundred. From these photographs astronomers find that the Milky Way is circular and more or less flat in form—quite like the lens of a mag- nifying glass, or a discus. Its diameter is believed to be between 25,000 and 50,000 light-years, and its thickness about 6000 light-years. That is our universe; only one of countless universes that make up the infinite universe. LANCE at any one of the photographs that illustrate this article. Consider that every one of the tiny dots shown on it is a sun probably as large and as bright as ours. Consider further that around each one of those suns there may be whirling a group of planets, and that each of those planets, if it exists, undoubtedly has its own satellites corresponding to our moon. Then recall that there are be- tween two and three billion of these suns in the universe in which the earth re- volves, and that this universe with all its wonders quite likely is only one unit—an atom—of creation. There you must stop, breathless and bewildered. To attempt to reach a con- clusion would be futile. Scientific knowl- edge has made tremendous advances since the days when man believed his earth was the center of the universe, but it has not yet progressed to a stage where it can offer us any definite aid in solving the pro- found mysteries of this world in which we live. Mr. Brown is preparing for an early issue another of his fascinating articles revealing the scientific wonders of the world about us. Milk as Fuel Runs Train. N AN astounding demonstration of the energy contained in milk, Dr. Herman N. Bundensen, Health Commissioner of Chicago, recently used dry milk in place of coal to run a train from Englewood to Beverly Hills, Ill., and back—a distance of about 10 miles. A thousand pounds of deteriorated milk, moistened and allowed to harden into lumps, was used in the test. A skeptical crowd at Englewood saw Doctor Bundensen at the throttle of the locomotive, while the fireman shoveled dried chunks of milk into the firebox. The locomotive pulled a train of five coaches carrying 200 passengers.

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aie | Your Meals and Health (Continued from page 41) You probably have heard a great deal about vitamins in the last few years. These are mysterious and elusive com- ponents of food, essential parts of the diet. They are widely distributed in different foodstuffs, and I shall not attempt to tell, except in a general way, in what foods you may expect to find them. For the prac- tical purpose of seeing that your diet is adequate, it probably will suffice to re- member that you will get all the vitamins you require if you eat dairy products, green vegetables, fruits, and unrefined cereals. Science now knows for certain that | many diseases are due entirely to deficien- > | cies in the diet or overindulgence in the wrong kind of food. I have mentioned some of the ills that may be traced to ex- cessive eating of meat. In addition, the cause of goiter has been found to be an insufficiency of iodine. Acid mouth and improper formation of the teeth in all likelihood are due to insufficient milk and green vegetables. The quantity of food to be eaten is largely a matter of occupation. For all peo- ple, though, three meals a day answer the eating program pretty well. The heaviest meal should be eaten at night, when most of us have the most leisure for digestion. O BOTH the slim and the fat I would say that the amount you consume is not the only factor in determining sta- ture. That is why stout people, anxious to “reduce,” frequently subject them- selves to all the tortures of starvation without affecting their bulk appreciably. An intelligent selection of food in variety and abundance will keep you in health and, unless you are suffering from disease, should prevent your becoming either obese or emaciated. Modern science does not admit that there are any such things as good foods or bad. Every food has its place in the diet. The problem of mankind is selection—the | right amount of food and the right kinds, | not the avoidance of certain foods. The only apparent exception to this tule is supplied by persons who seem un- | able to eat certain foods without suffering | very real physical ills. Some of these | acquire a skin rash when they eat straw- | berries. Others suffer distress after eating other seafood, and tomatoes also are “‘in- produce a burning sensation in others. Most of these unfavorable reactions to certain foods seem to be due to peculiari- ties in the physical composition of the find that you cannot eat certain foods in them, meanwhile supplying yourself with a satisfactory, well-balanced diet which you can both enjoy and digest. It takes all kinds of people to make a | world, and it takes all kinds of food to | make a proper diet. If you have a favor- Ite food, don’t eat it too frequently, especially not to the exclusion of other foods of which you may not be so fond, | but which are necessary to your bodily | | Welfare. To do so will throw your diet | Out of baiance and result in illness. — POPULAR SCIENCE MONTHLY 115 -WORKRITE- NEUTRODYNE OUTFIT res NEUTRODYNE OUTFIT (Licensed Under Hazeltine Patents No. 1450080 and 1489228) All Parts For A Five-Tube Neutrodyne Set Get the experience from building your own Neutrodyne Set. This WorkRite Neutrodyne Outfit contains all the necessary parts and has COMPLETE INSTRUCTIONS. It even contains a drilled panel, baseboard and mounting angle for proper mounting of transformers all packed in a strong neat box that will make a good radio tool box. No shopping around for parts. No uncertainty about getting the proper parts. This WORKRITE OUTFIT is the outfit you want. 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Write today and get all the PERRY LUDLOW CO., S. 2647 Dayton, Ohio POPULAR SCIENCE MONTHLY over | ————, Adventures in Home Ownership (Continued from page 63) The moisture from hot baths does not swell nor warp it, and it can be thoroughly yashed without damage.”’ “You have very beautiful wall papers,” Marion said as we looked about the various chambers. “I think in selecting them also it pays to buy good quality, don’t you?” “Most assuredly,” I told her. “Cheap papers soon fade and have to be replaced at considerable labor expense. Good ones hold their colors and last enough longer to more than offset the additional cost. Another thing it pays to provide well for is the hardware. Its good lasting quality and right design lend a satisfying char- acter to the home that is well worth the price.” “And how do you keep your floors looking so beautiful?” she asked. “The wax finish is responsible,” I ex- plained. ‘‘A waxed hardwood floor is the best to look at and the easiest to maintain. With a moderate amount of care it always looks as good as new.” “Have you a_ sleeping-porch?” asked. “Yes, and that reminds me to show you the Venetian blinds,” said I. ‘‘With them this porch is a screened piazza by day and a bedroom by night. You can raise them entirely or you can close the slats completely. The brightness of the early morning light always made outdoor sleeping objectionable to me until I learned about these blinds.”’ Jim HE third floor with a maid’s room, bath, and storage room suggested nu- merous possibilities. I pointed out that with dormers for lighting, it might pro- vide two or three chambers, in addition to storage space, or a nursery, billiard, or radio room. “Every available foot of attic space,” I said to Jim, “may be put to some practical use if one has the vision and initiative to do it. You can have a lot of fun working out such schemes and doing the work yourself after the house is completed.” For discussion of the building con- tracts I invited Jim and Marion back to the cool piazza. “One big advantage,”’ I told them, “‘is that you'll have good, complete plans and specifications drawn up by a successful and reputable architect. He'll advise you about letting contracts for the work, also, if you desire, he will supervise the building operations.” “Would you advise letting most of the work to a general contractor and perhaps making separate contracts for the light- ing, heating and plumbing, for in- stance?” “Tt could be done that way. But the most satisfactory scheme, in my opinion, is the single contractor who will be re- sponsible for the entire job. You then have just one reputable man to deal with, who usually can secure better terms, because of quantity buving and large operations, and can supervise the work more effec- | tively than you can. “Your architect will give you the names of dependable contracting firms with sound financial standing. Get bids on the | work from them in order to check one | against the other for possible excessive | costs. Then, unless the bids differ widely, give the job to the firm your architect | considers the most efficient and con- | scientious.”’ “Of course you’re a believer in written contracts?” Jim hazarded. “Most assuredly. Explicit contracts, duly signed, and drawn with due regard | to the lien laws are necessary safeguards,” I told him. specifications and drawings, all of which should be included as part of the contract. This is most important in case of any | disputes, particularly if action in the courts should arise.”’ “The architect, I believe, said some- thing about there being three principal types of contracts to choose from,” Jim. “The signature of both the | owner and the contractor should appear | not only on the contract but on the| said ROBABLY he referred to provisions | 99 for paying the contractor,’”’ I ex- plained. common. He may be paid a lump sum for the work he undertakes. He may be paid for all materials and labor, and receive in addition an agreed percentage of their cost. He may be paid for materials and labor and a fee for supervision fixed in advance. “Three different methods are | The lump sum basis has the advantage | of settling the cost in advance and is! preferred by most home-builders. The | third method is better than the second. | Neither settles the cost in advance, and unless the second is modified, the con- tractor may profit through increased ex- penditure for labor and materials.” “Now what about those lien laws?” asked Jim. “In some states they make the owner of a house responsible for all bills,” I | explained. ‘‘He is the only person with material evidence of having received the | benefit of labor and materials. Should | | | | | | the workers or material dealers not be | paid by the contractor, the law may give | them a preferred claim or lien on the} property, and the owner may have to’ pay a second time for such work or ma- | terials as the contractor failed to pay for.” “That might just about ruin mightn’t it?”? said Marion. “With a reputable contractor you have little to fear,’’ I assured her. ‘‘Before making the final payment to the con- tractor, however, it is well to make sure that all his bills for wages and materials have been paid. If you borrow any mort- gage money from a bank, building and loan or insurance company, its officials will probably help you in making sure on this point.” “Seems to me we’ve covered the ground pretty thoroughly,” said Jim, glancing at his watch. “I can’t think of another question to ask. All that remains, I guess, is to thank you again for much good advice and hustle out and take the big plunge into the game. Wish us luck, old man.” us, | I am glad to record that the wish has been fulfilled.

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Two Radio Receivers in One (Continued from page 64) four inches long by four inches wide. Looking at the amplifier from the rear, it will be seen that the baseboard is so fastened to the amplifier panel that there is a space of one half inch from the ex- treme left of the panel to the edge of the baseboard, but the baseboard projects one half inch past the right edge of the ampli- fier panel, thus fitting into the half-inch space between the left edge of the de- tector panel and the detector unit base- board. When fitted together in this way, the two units appear as a single unit. If care is taken to follow the wiring directions given below, no trouble should be experienced in wiring the set. Beginning with the bottom switch- points of both sets of switches, connect each switchpoint of switch 4 with the cor- responding switchpoint of switch 3. When the last or top switchpoint of switch 4 has been connected with a corresponding switchpoint of switch 3, one more switch- point (the top one of the series) of switch 3 will remain. HE next step is to run a wire from ter- minal 12 along the bottom edge of the panel to ground post 2. A wire then is run down to this wire from the switch arm of switch 4. Another wire is run from the F, terminal of socket 9 to the wire con- necting terminals 12 and 2. Then connect a wire from rotary plates terminal A of condenser 7 with the wire mentioned in the preceding sentence. One terminal, A, of condenser 11, is connected with this | wire. Next, connect the G terminal of socket | 9, not visible in the photograph, with one terminal B of the grid condenser and.leak 8. The F> terminal of socket 9, hidden from view by the top of the socket, is then | connected with the B terminal of rheostat | | 10. Terminal A of rheostat 10 is con- nected with terminal 13. The aerial post 1 then is connected with the switch arm of switch 3. The D termi- nal of jack 15 connects with terminal 14. The variocoupler now can be placed in position and wired into the circuit. Run a _ wire from the stationary plates terminal B of condenser 7 over the A terminal of grid condenser and leak 8, thence to the beginning or top end of the stator winding 5 of the variocoupler and terminating at the remaining or top switchpoint o1 switch 3. A wire is used to connect this wire

—— with the A terminal of the grid leak and | condenser 8. The first tap, at the tenth turn, of the stator winding is connected with the wire connecting the top switchpoint of switch 4 with the second switchpoint of switch 3. The second tap at the twentieth turn is | connected with the next set of switch- points, and so on down the line of taps till the last tap at the sixtieth turn is con- nected with the last set of switchpoints at the bottom of the panel. A glance at the wiring diagram will show how this is done. Now connect a wire from the B terminal | of condenser 11 to the A terminal of jack 15, and also connect one lead of the rotor winding with this wire. The other lead of the rotor winding is connected with the P (Continued on page 118) —

POPULAR SCIENCE MONTHLY Broadway around the world The biggest machines built by the General Electric Com- pany are steam turbine gen-

Compare these huge turbines with the tiny lamp used by sur- geons to examine the inside of an ear, and you will realize the variety of G-E prod- ucts. Between these extremes are lamps, motors, generators, switch-boards and other equipment—all tools by which elec- tricity works for you. erators of 80,000 horse power, used in great power houses. One of these giants could generate enough current to run all the street cars in twelve cities as large as Wilmington or Spokane. Ten could light a street as bright as Broadway running around the world. GENERAL ELECTRIC

Bis Eo DAT cee | Roll down the road on this dandy new bike—a dash- ing speedster—the wheel every boy wants. It’s a BLACK BEAUTY Shioped express preperd—disect from factory at whole- ale price. uarantee years. months’ accident insurance. 30 days’ trial. Large selection of models and colors. Tires, L: ,_H s, ete. E - SUPPLIES thing’ Yor"the Woke at Swnoiesae FREE—Big Black Beauty Bicycle Book HAVERFORD CYCLE CO. of PA. Established 28 yeara Dept. 387 PHILADELPHIA, PA. Be a Black Beauty Rider Agent

c:7 3 x it y ipa PER PAY L.D.Payne for 217 Days 4 says L. D. Payne. Frank DePries \ made over $325 profit in one day. “\\ Slidell and Viles sold over $25,000 YW in 2 years. G. Howard earned $100 “in one day. F. E. Mendenhall worked half time and made $100 < \ a week. W. E. Findlay ran up his commissions in a few months from $100 em to over $500 per month. Every Homes Auto Owner, Store and Factory a Live Prospect—Keetons Howard, and others, never sold Fire Extinguishers before. Our special training course starts you on road to success first day- If now employed, we can show you how to make big money during spare time. No Experienoe Necessary. Get our new Sales Plan—find out how to make real money. Territory going fast—write today! THE FYR-FYTER CO.,

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118 POPULAR SCIENCE MONTHLY For perfect teamwork radio parts must harmonize go Any RADIO RECEIVING SET will give better results when a Federal part is used in the assembly. But when you use all Federal parts you get all of the gripping thrills radio can give you. A quarter century experience in the manufacture of electrical communi- cation apparatus is behind the CxX- ceptional performance of Federal Sets and the 130 standard radio parts bear- ing the Federal iron-clad guarantee. A book, “The Radio Work Bench” aids the novice in avoiding con- struction pitfalls. Sold by Federal Dealers, 25c. In Canada, 35c. FEDERAL TELEPHONE & TELEGRAPH CO, BUFFALO, N. Y. New York Philadelphia Bridgeburg, Canada Boston San Francisco Pittsburgh Chicago London, England Federal95 ~- Variocoupler Federal 65 Audio =. Frequency Transformer MAKE MONEY-SELL RADIO! Radio offers the biggest money-making op- portunity on earth today. And the Ozarka Plan opens the door to this big opportunity. Look at the picture of this beautiful Radio Receiver. This picture was made from an actual photograph. By the Ozarka Plan that Radio Instrument can be the product of your own making—easily, simply and sure- ly. It will be yours to make, to sell and to reap a rich reward in cash profits. No experience necessary. You need not have much cash, All you need is spare time, de- termination and action. If you're that kind of a chap, the Ozarka Plan will start you on a straight line toward a real money-making business of your own. It can be as big and as profitable as you are ambitious to make it. We want good men in every county. Ex- clusive territory is going fast. Be sure and give us the name of your county. Write to- day for the Ozarka Plan. A wonderfully in- teresting book of facts, particulars and proofs. It is FREE. Act now. OZAR se Gs (4 Smoo around threads, handle SMOOTH-ON REPAIR BOOK the washer and on the and can never again come Try the same trick on any loose tool, knife, or umbrella . handle, door knob, etc., and the result will surprise you. sure cure for leaks of water, steam, fire, etc., at cracks or breaks in metal. Just the thing for repairing radiators, heat- ing boilers, the th-On bolt, the loose. Smooth-On No. 1 is also furnaces, tanks, pipes, leaky pails, etc. Keep a can on hand for emer- gencies. Sold in 6-02., 1-lb., 5-1b., and 10-lb. tins at alllive supply stores. SMOOTH-ON MFG. CO. Dept. 58 574 Communipaw Avenue Jersey City, N. J. 852 Washington Bivd. CHICAGO | with post 13, and post 21 is connected | with post 12. Two Radio Receivers in One (Continued from page 117) terminal of socket 9, completing the wir- ing of the detector unit. In wiring the amplifier, connect two | wires—16 and 17—with the P and B ter- minals of transformer 24 so that they can be slipped into the B and C terminal posts of jack 15. Run a wire connecting terminal 21 with the F,; terminals of sockets 18 and 19. Next, connect terminal 20, the A ter- minal of rheostat 28, and the A (positive) | terminal of C battery 26. The B terminal of rheostat 28 is connected with the two F>2 terminals of sockets 18 and 19; the G terminal of transformer 24 with the G terminal of socket 18; the G terminal of transformer 25 with the G terminal of socket 19. The two outside terminals D of jacks 22 and 23 are connected together, and with terminal 27. The P terminal of socket 18 is connected with the A terminal of jack 22; the P ter- minal of socket 19 with the A terminal of jack 23; the P terminal of transformer 25 with the B terminal of jack 22; the B terminal of the transformer with the C termina! of jack 22. The two F terminals of the transformers next are connected and a wire is used to join the connecting wire with the B (negative) terminal of C battery 26. This completes the wiring of the re- ceiver. F THE detector unit alone is to be used, the positive A battery lead is connect- ed with post 12; the negative A battery lead with post 13; the positive B battery | lead with post 14, and the positive of | the A battery and the negative of the B battery are joined together. When both units are to be used, the battery connections for the detector unit remain the same. Wire 16 is connected with the B terminal of jack 15; wire 17 with the C terminal of jack 15; post 20 Post 27 is connected with the highest voltage terminal of the B battery. Best results are obtained with the UV-199 and | C-299 tubes if 45 volts are used for the de- | tector and 90 volts for the amplifier. When | it is desired to cut down the weight of the | outfit, as low as 22 14 volts can be used for both detector and amplifier. As a matter of fact, I have had fairly good results with | a B battery voltage of 41% volts obtained by using a 414-volt C battery. ‘ The knack of tuning the set is acquired easily. The grid leak resistance should be adjusted to the medium position. The tickler coil then can be set at 90 degrees to the stator coil and various combinations of switch settings can be tried to determine the best combinations for a particular station. At each setting, the variable condenser is adjusted through its range until signals are heard. The rheostat should be turned on sufficiently to give fair signal strength, but not enough to cause the tube to oscillate. When a signal is tuned in fairly well, adjust the tickler coil. Slight readjustment of condenser, grid leak, rheostat, and tickler coil settings will enable you to clear up the signal and bring it in good and strong. ee

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ir- | VO =) Na an sts ith er- 1a] WO G G of Op er, ted er- nal ner 2 B ae, als ted ing | at sed, ect- ery | ery | > of | ie B | the unit cted pay t 20 cted hest Best and 2 de- | Then f the d for | atter | with | ined uired ld be The es to tions mine cular enser gnals 1 be ignal ‘tube ed in grid tings l and ee | Here Are Correct Pease | to Questions on Page 60 |1. Because he has larger muscles with ' more muscle fibers in them. They can exert stronger pulls than the smaller mus- cles of a woman. This difference in the | size of the muscles is part of the general difference in the size of the body, women | being, usually a little smaller than men. | 2. If you have a burning glass you can concentrate sunlight through it and set fire to paper or wood shavings. With a piece of steel and a flinty stone you can easily strike a spark just as our great- grandfathers did before matches were in- vented. With a little thin paper or very dry cotton to serve as tinder you can nurse ' this spark into a flame. 3. The thickness of the earth from pole to | pole is 7900 miles. It bulges a little in the middle and its thickness at the equator is 27 miles more than at the poles. The dis- tance around the earth on the surface is | 24,900 miles. The highest mountain has about the same relation to the size of the earth as the thickness of a sheet of paper pasted on an orange. 4. The Dead Sea is very salty. It contains nearly 25 per cent of salt and there is no known fish that is able to live in so strong a salt solution as this. | 5. Whenever a glacier reaches as far as the sea the end of it flows out slowly into the water. Pieces break off and float away. These are icebergs. 6. In the wood are a great many very small holes, or cells. Some of these have a little moisture in them. When the wood gets hot, this moisture turns to steam and bursts the little cells in which it is. This makes a noise like a small explosion and a great many such noises together make the crackle of the fire. | 7. The sulphur-bottom whale, which may | be as much as 85 or 90 feet long and may | weigh nearly 100 tons. No prehistoric | animal was as bulky as this, though two | or three of the great extinct reptiles may | have been a little longer. 8. So far as we know they cannot perceive images as our eyes do, but they can tell the difference between light and dark. | Many plants will turn their leaves toward the light. 9. Probably gold. Metallic gold was to be , found in the beds of streams. It was used or ornaments before any other metal was discovered. The first metal put to practi- cal use was copper, made into knives and other implements at least 6000 years ago. 10. We are not sure, but it is probable that they migrated from Asia across the Beh- | Ting Straits thousands of years ago. The easternmost point of Asia was probably connected then with Alaska by a land | bridge, since sunk beneath the sea. | ll. In the same way in which blotting- | paper absorbs ink. The water is taken up into the millions of tiny holes between the ibders in the cloth of the towel. 12. Because that is the shape with which | 4 certain amount of air can be inclosed by the least possible amount of the soap film. The film tries, as all matter does, to draw itself as closely together as possible. The bubble gets as small as it ean without bursting and letting out the air inside. POPULAR SCIENCE MONTHLY “HE mechanical principles of Magnavox Reproducers are as marvelous as the vocal chords of a great singer. CThe Reproducer Supreme with a Human Throat7 ETWEEN Magnavox and ordinary “loud speakers” there are certain es- sential differences hidden awayin the base of the instrument, insuring for Magnavox utmost clearness of tone. Reproducers M4—the latest Magnavox achievement: requires no battery a és $25.00 M1—also constructed on the semi-dynamic prin- ciple, requiring no battery - $35.00 R3—famous electro-dynamic type: new model f. with Volume Control $35.00 \ R2—same as R3 but larger size: new model with ‘y: Volume Control $50.00 alg Combination Sets A1-R and A2-R—the only instruments combin- 4 ing electro-dynamic Reproducer and Power Amplifier in one unit. $59.00, $85.00 Power Amplifiers Al, AC-2-C, AC-3-C—the most efficient audio- frequency Amplifiers: one, twoand threestage | | $27.50 to $60.00 i ! To obtain the fullest enjoyment from your receiving set, equip it with the Magnavox— for sale at good dealers everywhere. THE MAGNAVOX CoO., Oakland, Calif. New York Office: 350 West 31st Street a Canadian Distributors: Vv Perkins Electric Limited, Toronto, Montreal, Winnipeg

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120 The Greatest Dist POPULAR SCIENCE MONTHLY r Opportunity First Franchises on (i: Another great invention has gone through the stages of perfect- ing, simplification, and moderate pricing through quantity production —And, just as happened when good automobiles became moderate priced, demand has become universal in every section of the country. You will be amazed when you learn the total sales figures of the past two years, on the new Oliver Fur- nace Burner. It is this demand that now leads us to accept as distributors, men to whom we can turn over established business in cities, countries and territories. The opportunity will appeal to men who are seeking a permanent business of their own— limited in size and profitableness only and business capacity. IONEERING work in the oil burner field is over. The past few years have seen oil burn- ing for Domestic Heating and com- mercial purposes definitely accepted. The Oliver Engineers have developed a furnace burner without noisy motors, electricity or moving parts— efficient to an unknown degree— Listed as Standard by the Under- writers’ Laboratories and already tested by two years of actual use in thousands of homes. Sales of the company have gone to an unprece- dented peak. Over two hundred thousand homes have already been equipped with burners by the Oliver Oil-Gas_ Burner Company—direct from the factory. This is but a meagre indication of what can be ac- complished through a_ thoroughly organized national wide distributing organization. A Proved Proposition As a logical course we now wish to have permanent dealers in every city, with Distributors to cover Counties and Sections. We will ex- pect these men to fill orders created by our national advertising, to take over retail business heretofore handled direct from the factory, and to arrange selling and_ servicing facilities in their own territories. This is not an untried proposition. The sales records of individuals al- ready working under this plan have been phenomenal. The completeness of the Oliver line, which includes a burner for every type of furnace, cook stove and heating stove, makes OLIVE Dept. 754 CANADIAN as BURNER I OLIVER OIL-GAS BURNER CO. ‘ws Oliver Bldg., St. Louis, Mo. | DISTRIBUTOR: OLIVER BLDG., TORONTO, CAN. Oldest and Largest Manufacturers of Oil-Gas Burners in the World ais i eens ii ia by their responsibility The every householder a prospect. selling season is 12 months long. An Opportunity that Must Be Grasped Quickly If you are the type of man who would have realized the possibilities for money-making with the incep- tion of the automobile, you are likely the type of man we are looking for. A proposi- tion can be outlined to you that will be entirely commensu- rated with your position and ability. We seek men to whom we can lay down definite figures of business done—with refer- ence to any city or territory. The general plan of Oliver territory organization is briefly explained under the captions The Oliver Dis- tributor, the Associate Distributor, and the Sales Agent herewith. Write for Sales Plan It is advisable that interested par- ties should get in touch with us at once. We have prepared a complete prospectus which outlines our whole proposition. It will be sent you upon request. More definite information can and will be given if you will indi- cate on the coupon or tell us in a letter, the tvpe of Oliver Territory in which you are in- terested. Write or wire at once to : I dealer plan. Name ddress oy i 05 so jst Ue The Oliver line includes 16 models of burners for every type of furnace, cook stove, heating stove, water heater, etc. THE THREE TYPES OF OLIVER TERRITORIES THE DISTRIBUTOR Oliver Distributors receive appointment in logical Distributing Centers with exclu- sive rights usually covering several counties. They usually operate on a retail basis in one or more counties and furnish merchandise to Associate Distributors in the other counties of their territory. 4 THE ASSOCIATE- DISTRIBUTOR The Oliver Associate Distributor operates in one or more counties on an exclusive basis, where he is expected to have facilities for selling, installing and servicing burners. He receives merchandise direct from the factory or from a Distributor. 3 THE SALES AGENT Oliver Sales Agents act as city dealers or may receive appointment for territories on either exclusive or non-exclusive basis. OLIVER OIL-GAS BURNER CO. Dept. 754, St. Louis, Mo. Please send me full details of the New Oliver distributor and This does not obligate me in any way. Ae | ee ART COLOR PRINTING CO., NEW YORK Mention the character of appointment you are interested in or describe t territory here, for specific information. e | | | | | | | a

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fhe yao" es 16 every stove, eater, itment exclu- unties. in one dise to yunties ‘E~ R erates clusive cilities urners. m the NT ers or ries on = utor and ——$——— yr describe er ak LMA, Tee Foe us - yon ee PRS Tae BSC hs Se POPULAR SCIENCE MONTHLY Crosley 51-A, $14.00 Crosley 50, $14.50 Crosley 50-A, $18.00 Guaranteed Satisfaction at a Reasonable Price CROSLEY 50—A new one tube Armstrong Regenerative Receiver. We believe this to be the most efficient one tube receiver ever put on the market. Uses any standard storage battery or dry cell vacuum tube. Price $14.50. CROSLEY 50-A—A new two stage Audio Frequency Amplifier to match the new Model 50 Receiver. When used in connection with the Crosley Model 50 Receiver, it gives the equivalent of a three tube regenerative receiver. Price $18.00. CROSLEY 51—In twenty-four days this receiver became the biggest selling radio receiving set in the world and it holds that position to-day. It uses two standard storage battery or dry cell tubes, rezenerative detector and one stage of audio frequency amplification. Will bring in local stations on the loud speaker at all times, and under average conditions will a'so bring in distant stations on the loud speaker. Price $18.50. CROSLEY 51-A—A new one stage Audio Frequency Amplifier to match the Model 51 Receiver. Combined they give the equivalent of a three tube receiver. Price $14.00. Write for Descriptive Circular CROSLEY 52—A new three tube Armstron~ Regenerative ‘Receiver. It is unusually efficient, will provide loud speaker volume on distant stations under practically all conditions, and is in every way an ideal receiver for the home. Price $30.00. CROSLEY 51-P—This is our new portable set. It is the Crosley Model 51 two tube receiver mounted in a leatherette covered carrying case, battery space and all self-contained. Price $25.00. CROSLEY TRIRDYN 3R3—This three tube _ receiver gives the efficiency and volume of many hve tupe sets. Ine corporating Radio Frequency Amplification, Regenerative Detector with one stage of Reflexed and one stage of straight Audio Frequency Amplification. Can be calibrated accu- rately—stations logged and returned to at will. Used on outdoor or short indoor antenna and is, we believe, the most efficient and sharpest tuning receiver on the market at any price for bringing in long distance stations. Price $65.00. CROSLEY TRIRDYN 3R3 SPECIAL—This receiver is ex- actly the same as the Trirdyn 3R3 except the solid mahogany cabinet is larger to contain ‘‘A’’ and “‘B”’ Batteries required when standard dry cell tubes are used. Price $75.00. For Sale by Good Dealers Everywhere © THE CROSLEY RADIO CORPORATION POWEL CROSLEY, Jr., President 817 ALFRED STREET Licensed under Armstrong U. S. Patent No. 1,113,149 Better-Costless 5.3 Sic, RAAT eet CINCINNATI, OHIO Crosley Owns and Operates Broadcasting Station W L W res rd Radio Products * os ea SEES, Og tae ws P&E EP EST ee eT ae al ae PPD yd Ro Prad SOA nate aie EIR AR EPO ES I td naa Re fe a: = OEY Kat She Hata 32: Om os @ Ste as