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IN PICTURES 0 NON -TECHNICAL RADIO' ARTICLE 4 - - -4\ DIAGNOSIS BY RADIO \ A 1 !` \t. See Page 978
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EXPERIMENTER PUBLISHING COMPANY. NEW YORK, PUBLISHERS OF NEWS - SCIENCE & INVENTION - THE EXPERIMENTER - MOTOR CAMPER &- TOURIST' J. -RADIO " - 4 Combines distance,selectu)ity, powez'
deep full tone, beduty and simplicity! 1
Looks like-and Performs like-a $200 radio set BUILT TO GIVE LOUD SPEAKER ENTERTAINMENT FROM STATIONS
1 THOUSANDS OF 1 MILES DISTANT WHILE LCCAL STATIONS ARE BROADCASTING = costs only $
"Coast to c I I Oast I e reception -a / 17,: iP1G11.tL. r verified by 71firaco7fsers Do not judge Miraco seta by their NOTE, prices. Enormous production makes them coat lens. They aro built-by pioneer wet makers--of highest grade parts. They embody lmprovemeuts,reflnement and features used in the most costly seta. Every hi Iracouser loan enthusiastic booster-these letters are typical of the many we receive. Europe Send coupon Oklahoma Hears for SPECIAL Nov. 27th was able to get two of the for- eign stations on my Mimeo, also Porto OFFER! Rico and Guatemala. Mexico.-W. J. Lowe. Verdun, Okla. DIVE TUBE OUTFIT IN BEAIII'IiUITL oLm ~pawl' CASE] Michigan Hears Germany Completel ybutlt,thnroughly tested and factory guar- toned "coast to coast loud speaker" set. composed of My Mimeo is working fine. Nov. 28th I anteed by one of America's oldest and most reliable finest parts, housed in solid mahogany, equipped got 5N0. Newcastle. England. and LP, manufacturers of quality sets! Years of experience with the latest improvements, refinements and Berlin, Germany, Can you beat that rec- andquautityproduction explain itsalmostincredible features found on costliest sets-and factory guaran- ordP-TLomas Wafter Howell. Mich. price. Users, who have deluged us with commenda- teed! An instrument approved by radio's highest Pennsylvania Hears Paris tions.say that friends who see and hcaritareamazed authorities! A set anyone Can connect and operate. through Relieve Mlraeo the best distance -getter on that it sells for less than $150or$200. Radio experts, Even beginners learn quickly to cut the the market for the price. Nov. 24th I who know Stood construction and quality parts, are "locals," get distant stations loud and clear, log picked up Pads, also Havana. Cuba. and equally astonished. You, too, will be delighted. stations and return to them at will. (Full directions San Juan, Porto Rico. Nov. 25th I picked thrilled, amazed with your big five -tube Miraco with each set.) It is non -radiating, non -distorting, up SNO. Newcastle, England. Nov. 27th "Ultra 5" in its beautiful hatted -rubbed solid ma. non -howling. Has cut-out switch-and a first stage cot 5N0 and 213D. Aberdeen. Scotland. hogany cabinet! You'll be envied by radio friends phone jack for tuning-on Bakelite panel. All wiring con- Now have 98 other stations on my log to who paid big prices for their outfits. cealed under Bakelite sub -base. Works on storage battery date, keeluding KOO, Oakland. Calif.- or dry cells. Literature describes other newest features. Earl C. Way. Coleman. Pa. Imagine getting all this for $75-a beautiful sweet Indiana Hears Europe Nightly During the European test I had some for- Other4' iracnLongDistanteSets$1t4úp eign station every night on my Miraco. AuRAc0 Nov. 22nd I also heard New York, Lea Users tell us that Miraco Model R justly deserves its title, "Radio's RADIO Angeles, Canada. Texas and 91 others.- - finest low priced quality receiver." One tube acts as a tuned radio Ind. GETS'EM Rudolph, Evansville. ti: frequency amplifier and detector combined. A great distance getter. Kansas Hears Coast to Coast ' Easy to operate and log. Covers all wave lengths 150 to 825 meters. COAST 243 a Am using a Miraco and will let the following Or.. Like all Miraco sets, it operates on storage battery or dry cells, COAST list of stations toil what I thh.k.of ',streets. a - ' Never such value before at only $14.35 These new not all the stations I have tuned In as do not "log"a station unless I hear These Mimeo sets are as easy nil a pbono it at least twice. The unrecorded stations This wonderful new Miraco Model R-3 is the ' [{ ? graph to operate. Built throw about of Include several in Canada, two lu Mexico three -tube, lung distance, loud speaker set ~- highest grade parts. Full directions for and one In Cuba. Expect to do better still: that has created such a sensation. Easy to connectingot. N and operating euppbed with each F I, EGO, On k avid.d. Cal.; experience necessary. Thethreeand K Hi. K Los Angeles; tune and log. Covers wave lengths 160 to 625 O. e four tube nets havecut-out ewtteb and Ant KCO. as HZ, Spring- KPO, San Francisco; meters. Detector acts also as a tuned radio ¿. ateae phone jack Each set completely built. field, Maas.: WAY, Schenectady. N. Y,; frequency amplifier. tat a ea audio frequen- _ thoroughly teeter) and factrr guaranteed. WOO, Philadelphia- VISES, Atlanta. Oa.; n amplification,. has no equal for aimpGrity, vol - KFDX, Shreveport, La., WOAI and WCAR. ume, range or dawns.. at awahere near lis price Mira co R-3 only $29.50 San Antonio Tex.: WFAA and KF'OP, Dul- .i IIaaas,,Tex.. WRAP, Ft. Worth. Texne; WWJ, The famous Niraeo Model MW four tube "coast to coast laud speaker" outfit Detroit,. WMC. Mem his, Tenn.; WSAI and whlch users all over the country report outperforms and outdistances much :7` au WLW, Cincinnati; WBT. Charlotte, N. C: costlier nets. Comes In a solid mahogany cabinet. The improved 1025.model Is LVOR, BrInlo; W BAR, Minneapolis: WCAM: equipped with cut-out switch, first stage phone jack for tuning (removing plug Villanos a, Pa.; KBD. St. Lonis. WOAW. automatically switches program to loud apnea. -r)and other latest features. tee Omaha; KOKA. Pittsburgh; W EBB, KYW, Employs one stage of radio frequency amplification, detector and two stages WON and WMAQ, Chicago: WTAS, Elgin. of audio frequency amplification. Another unmatched Miraco value, 454.50. Ill.. and twenty others In Miaa"nri. Kansas Iowa. Illinois, Minnesota. Nebraska and -IDEALERSf)OBEERSI--- \ Oklahoma.-J. A, West, Augusta, Kansas. All the Proof you want it waiting forYou! Write for the new Mlraco proposition. Nation -aide use and popularity of Michigan Hears 180 Stations Reports from the many users in every state prove Miraco Tuned Radio Fre- Mimeo Sots their amazingly low prices quency sets costing up and our extensive advertising, makes Am mending Batorof stations I received on my Receivers-at rock bottom pnces-have efficiency of wanted bend coupon. )l Irace In 8 week.; EGEA, KDPM. KFCH, to three times as much. Remember that Miraco Sets are the product of a long them everywhere. KECV, LFDA. KFDP. KF'DU. XEHF',KFI(Loa established, reputable manufacturer-pioneer builders of sets. Send for further AGENTS! Angeles), KOP. KOL KRE, WAAD WAAF, evidence that they are Radio's finest moderately priced receivers. All Miraeo I The tone, and WAI1J, WBAD, WBBA. WBZ, (Springfield. sets bear the endorsement of radio's highest authorities. itloilcoupon now ne billttrrulof Sets makesthem easy W'CAE, WCALWCAM,WCAP,WCAS to sell. Send coupon for proPeetion; good ter- Maas.), for latest bulletins and plenty of additional testimony from users leaving no ritory open. WCBD WCE, WCK. WON, WCX. WDAE, doubt that "Miraco Radio Coast to Coast." W DA F, WDAJ, WDAK. WON, WDT, WDZ. Gets'ein WEAF, WEAL WEAN, WEAO, WFAA. (Dal. Ias,Tex. I,WFAF,WFAV WFIWGAN,WGAY, WGAZ, WOL. WAM, NOR, WHA, WOY. RADIO CORPORATION BMA'. WHAR, WRAP.. WRFC. WIP.WJAJ, MIDWEST of Sets WJAN. W.1 AR, WJAR, WEBH, WLAV, Pioneer Builders Cincinnati. Ohio WLW, WM vi. w'NAC, WNAQ. WOAR.WOC, WOO., (Philadelphia), VOS, WDAP,WPAZ, Eighth Street particularsOhio WPO. WPI, WQAJ, W'SAL WRY.WTAO, 409 -T East OFFER your SPECIAL all ( ) USer. WTAS. WTA.W W J. W TA K. W LAC. W H N, free ( ) (and (New York City ), W DL.Thi s Mall the lint Send Mliiraco Sets ( ) Jobber. I -have on hand. At the house I have 180 regarding ...... fnab.-Howard L.Qoodslll.Cltnton,Y.lch. ,,,,....- ,-..,... ¿-,,...... Address ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,t,. Science and Invention for February, 1923 961 arnEle-c: rci
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; qb - .. s za Earn Sbó to $200 a Week Why work at Cull uninteresting work, at low pay, with no future? In 12 weeks I will train you for a big pay job where you can command -$60 to.$200 a week as a COYNE TRAINED MASTER ELECTRICM. EXPERT or you can go in business for yourself with very small capital and make up to $15,000 a year. Men trained as I train them are in demand everywhere. The great development of the Electrical industry makes the demand for trained men tremendous. Big opportunities and advancement for those who prepare now. The Coyne school was founded 26 years ago and my thousands of SUCCESSFUL GRADUATES are living proofs of wha= my training can do for ANY AMBITIOUS man; Many of these fellows will te1 yetiin my bigfree book what Coyne has done for them, Complete Electrical Training In 12 Weeks I train you thoroughly on the greatest outlay of ACTUAL You Don't Need Education or Experience ELECTRICAL t acknery ever assembled in any school. You work You don't nerd a lot of schooling to master my course. You don't have with your hands on aft kinds of Electrical apparatus, door tells, house to be a high school graduate or even a grammar school graduate. My wiring, armatures. switchboards, dynamos, everything to make you n ethod of instruction is cleat and plain, and yet thorough. an all around ELECTRICAL EXPERT. This REAL WORK o, - a -d if you can understand plain English I will make you an with REAL tools, on REAL machinery trains you many'3 electrical expert even though you haven't a lot of education - tim FASTER, many times MORE THOROUGH than try. o: any prevtcus electrical experience. \ 44, ing :o learn in tae Feld or by books or lessons. Coyne Trains You For Life No Books-No Lessons-No Classes . 444' á Can get a free life scholarship which enables 41You -You Do Actual Work! you to stay longer than the required time if you O I do not attempt to teach you by books or lessons. I train you care to, or you may return at any time to take up to work with your head and hands on the same kind of Elec. rew work I'm constantly adding to my school triedMachinery usec in power houses, industrial plants and to make it the most modern at all times. ' - on the outside, under actual working conditions, with in- structors at yol_r site. I have no classes, every student Earn While You Learn H. C. LEWIS gets individual t_ain:ng. My emplojmentdepm-tmentwill assist 0- /'rr"'°`ac you to a part dme jot where you can COYNE Free Radio and Auto Course make a good part living Electrical School For a short time anly I am including ABSOLUTELY FREE panses while trainin ,. and they 1300-1OR'.NarriroaSL my Dig new Racio and Auto, Truck and Tractor vs ill assist yoato get BIGPAY 533-2 Course H. C. LEWIS. Dept. Eletrical Course. President job ongraduation. Chicago. Illinois Thisbig.hancsome Dear Sir:-Please send me Get My Free Book . absolutely FREE your big newtookjustoff new book and toll particulars the press-size 12x15 in.-shows actual photo- . of your special offer and two graphs of my big shops. Cost me a dollar to courses FREE. COYNE print, but it's yours REE if you mail coupon. You Owe it to your- Electrical School self to get the facts. Name 130)4310 W. Harrison St., Dept. 533-2 CHICAGO. ILL. / f, Address MAiL THIS COUPON: Ñ:OW ! ll . r Z,1, MiI;IIIIIIIIUIIIIIIIIIUV IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIILi4124 - .. . .
Vol. XII. é February, 1925 Whole No. 142 No. 10 I FORMERLY ELECTRICAL. EXPERIMENTER IN OUR NEXT ISSUE Member Audit Bureau of Circulations Can a Perpetual Motion EDITORIAL & GENERAL OFFICES: 53 Park Place,'New York City Published by Experimenter Publishing Company. Inc. Machine Be Patented? (H. Oornsbark, Pres.; S. Gernsback, Treas.; R. W. DeMott, Secy). The laws of the Patent Office Publishers et SCIENCE & INVENTION, RADIO NEWS. THE EXPERIMENTER of the and MOTOR CAMPER & TOURIST. United States state that a perpetual mo- 1,,,nnuiv,,,, aa1,m,,,n. ,,,,,,,,.,,,, ,n,a,,, ,,,,,,,,,,,,,,,,,,,,,,,,,u,1,,,,,,,,,,,,,,,,,,,,,,,,,,,,11 tion machine when so called, cannot be , 1,m ,,,n,,,,,aaaaaww,amau,u,.,, patented unless accompanied by a work- ing model. We will show how several in- Contents S®T ventors have gotten around this law by February means of adroit descriptions of their ma- POPULAR ARTICLES AUTOMOBILES chines. However, even with these patents Editorial 973 Automatic Railroad Crossing Gate 977 in existence, our $1000.00,prize offer still By H. Gernsback. English Tire 1002 remains unclaimed to date. "Shipwrecked" On Stage 974 Building an Auto Speedster 1004 By * * * By A. P. Peck: George Arthur Luers. Movie Film Duplicates Figures 975 What Do You Know By H. Winfield Secor. Viewing Marl From Mountain Top 976 ELECTRICITY About Sun Dials? Shooting the Air to Test Wind 976 "Shipwrecked" on Stage 974 =I By Ernest Brerntecke. The Radio Teledactyl The past and present types of sun dials lutomatic Railroad Crossing Gate. 977 978 ffi Portable Electrocardiograph 979 will be described by a well-known author- By I. W. Von Stein. Latest If New York City's Water Supply Patents 1020 ity on "Time who for several months past Oracle 1022 Should Fall as Rain 977 Patent Advice has contributed man interesting articles By C. N. 1034 Holmes. Edited 1, A. P. =I on that subject to this magazine. He will The Radio Teledactyl 978 Peck. .t show how sun dials have been passed down By H. Gernsback. Portable Electrocardiograph 979 through the centuries, changing very little Trick Sub -Sea Photography 980 RADIO ARTICLES in form and always By Edwin Shaliert. remaining one of the The Radio Teledactyl 978 simplest and most stable of time Social Life of the Ant 982 Radio Pictorial pieces. By Dr. Bade 1010 * * Ernest A New One-WGBS * Find the Hair-Find the Criminal 984 1011 Photos Across the Atlantic 1012 Did You Ever See By Mel Wharton. By Leon L. Adelman. Science in Pictures 985 Broadcasting from the Clouds 1014 An Actor "Make Up"? The Living Death 986 Capabilities Your By John Martin Leahy of Receiving Set 1014 Simple as the art A l00 -Foot Antenna Mast 1015 of "making up" may "Death Ray" in Movies 988 By Fred A. Parsons,-2AB31. seem, still it is rather complicated in order Poison Gas Shells 989 A Low Loss Broadcast By Lieut. S. Receiver 1016 to produce a satisfactory effect that is not Robert E. Sadtler, U A. By Frank Fritncrman, 2FZ. .Dr. Hackensaw's Secrets 990 Three Good Circuits too glaringly artificial. An authoritative By Clement Fezandié. 1017 Radio Oracle 1018 article will deal with the various steps in Everyday Chemistry 992 the art of "making up," each By Rantoud B. Wailes. step being Glands Assist Evolution 993 fully illustrated and described. Safety Razor Blade Gives 400 CONSTRUCTOR ARTICLES * * * Shaves 993 Science of Christmas Toys 994 How to Build an Auto Speedster.. 1004 Were You Ever Up By Joseph H. Kraus. By George Arthur Luers. Stereoscopic Movies 996 4n Emergency Foot Bridge 1006 In a Dirigible? Small Microscope From Glass Phosphorescence 997 Beads The fascinating subject of how dirigibles By Raymond B. Wailes. 1006 are steered Specialized Closets 998 and navigated will be dealt By William 31. Butterfield. with by an expert on aeronautics. The il- Stunts for the Smoker 999 CHEMISTRY ARTICLES lustrations By Walter B. Gibson. will be complete and explicit Find the Hair-Find and will show each and How We Digest Food 1000 the Criminal 984 every little detail, By Ismar Ginsberg. B. Sc. Chem. Eng. By Mel Wharton. all of which are so in Magic Poison Gas Shells 989 necessary the safe for Everybody 1001 By navigation of a leviathan By Pry. Joseph Dunninger. Lieut. Robert E. Sadtler, U S'. A. of the air such Everyday Chemistry 992 as the Shenandoah Soap DollActor 1002 By or the Lis Angeles. More Gamblers' Tricks Exposed 1003 Raymond B. Wailes. * * * By Mark Mellen. Phosphorescence 997 Ilow We Digest Food 1000 The above are just a few of the treats Rr Isntar Ginsberg. B. Sc. in store for our readers in the next PRIZE CONTESTS Wrinkles, Recipes and Formulas 1008 issue. Hundredsof photographs and Howto-MakeIt Department- illustrations will also be published, $30.00 in Prizes 1007 ASTRONOMY Scientific Humor-Prizes for Best ARTICLES accompanied by short, to the point descriptions. -. Jokes 1021 Viewing Mars From Mountain Top 976 cu Awards in $1000 Monthly Contest 1024 The Artificial Star 99b
HOW TO SUBSCRIBE FOR "SCIENCE AND CAMPER & TOURIST. Subscriptions may be order and remittance before a renewal, delivery of INVENTION." Send your name. address and re- In combination with the other publications the magazine Is stopped. mittance made to Experimenter Publishing Co.. 53 Park lust mentioned at special reduced club rates. Send ('RANGE OF ADDRESS: Notify us as far In ad- Place. New York City. Checks and money orders for club rate card. Subscriptions start with vance as possible, should postal giving your old address as well be made payable to Experimenter Publishing the current Issue unless otherwise ordered. as the new one to which future magazines are to Co., Inc. Mention the name of the of your subscription we enclose go. It takes several weeks are magazine you ON EXPIRATION to make an address ordering Inasmuch as we also publish RADIO a renewal blank In our last number to you, and change on our records. NEWS, THE EXPERIMENTER and MOTOR notify you by malt. Then unless we receive sour
SCIENCE AND INVENTION is published on the INVENTION. 53 Park Place. Ness York City, N. Y. Rept. 15. 1924, at Post Office, Atlanta, Ga.. Chicago. 25th of etch month. There nre 12 numbers per year. Unaccepted contributions cannot be returned unless ILL, Los Angeles, Cal., San Francisco. Cal. Title 12.50 Registered Snhscrlptlon price Is a year In U. S. and pos- full postage has been Included. ALL accepted con- at the Patent Office. Copyright. 1925, sessions. Canada and foreign are paid for on publication. by E. P. Co.. Inc.. New York. The Contents of this countries 53.00 a year. tributions Magazine are S. as INVENTION. Monthly. copyrighted and must not be repro- U. coin well as U. S. stamps accepted (no for- SCIENCE AND 4PPlicatlon duced without full eign rob) or stamps). Single as second class matter made at New York, N. Y. with giving credit to the publication. copies, 25 rents each. SCIENCE AND INVENTION Is for sale at all A sample copy will be sent gratis on request. additional entry at Long Island City. N. Y. Post newsstands of In the United States and Canada; also All communications and contributions to this jour- Office. under act Congress of Starch 3. 1am at Brentano's, 37 Avenue nal should be at Jamaica. N. Y. de ('Opera, Paris. Mem- addressed to Editor, SCIENCE AND formerly entered Entered on ber of the Audit Bureau of Circulations. New York City Western Advertising Representatives Pacific Coast Advertising Representatives Kansas City General Advertising A. J. Advertising Representatives Dept. Flnuean & McClure Norris Hill Co. George F. Dillon = 53 Park Place St.. Chicago. III. Hearst Bldg.. San Francisco. Calif. 720 Cass Republic Building, Kansas City. M1to. l(1v 1/.14.7i7 l 'pIÍIUIIIIIIIIIIIIIIIIIIII ilimÍIIIIIÍIIItIÍIIIIIÍIIIIiliiIIÍIIIIlIIIIIÚIIIllitiliÍIIIIIilli1111111111011IIIIIIIIIIA 962 Science and Invention for February, 1925 963 Send For This Sensational Radio Bargain BooK'FREE COMPLETE PARTS Order Direct From This Page! Save FOR Big About One-half! Compare our prices with others. Only highest grade nationally ACMEREFLEX...be $17.45 Radio d \v known GUARANTEED parts. OUR G U A RA N T E E ACME 4-Tube tee PROTECTS YOU. Money cheerfully refunded if you REFLEX... $39.95 Book are not satisfied. Be sure to write your order and state prices with Genuine Acme parts 04. _ - plainly Send post office or express money order or band draft for ` total amount to insure prompt shipment. ALL PRICES ON THIS as specified, drilled Bake- Gu CHARGES RIGHT TO YOUR DOOR. Refer lite panel and full wiring PAGE INCLUDE SHIPPING G to any bank or commercial agency regarding our reliability. If your favorite diagram. ,a circuit is shown here, order direct from this al. No skill required to build your 5415 own radio with Randolph 'arts. Panels are all drilled. Instructions are simple and complete. Everything cornea rmdy to assemble. Order direct! All ship'g charges prepaid. Send COMPLETE PARTS FOR for 2 -Tube Harkness l --f Aleñce . Set 1 including Licensed Hark- /t ^i ness Coils, Drilled Panel kC and wiring diagram. Easy COMPLETE PARTS FOR to build. Won- el - w+ 7.95 derful results. BREMER TULLY .±11_,A., 5 -Tube Nameless OUR GUARANTEE Circuit FOR3AND5-TUBE NEUTRODYNE RECEIVING SET Parts Every article exactly With Genuine Bremer -Tully Genuine Hazeltine Licensed Neutrodyne Furnished. 1 7x24x',f, Drilled Panel PARTS FOR 5 -TUBE SET as represented. Every Parts, including Drilled B ake- 2 Thordarson or Columbia Audio Transformers 35 feet Hook-up Wire 3 4' Bakelite Dials 7 Started Binding Posts 1 Kit Consisting or 3 Hazeltine article Is tested before lite Panel and Instructi ons. 2 Precision Jacks 1 Grid Leak and Condenser Licensed Neutroformers & shipping. Complete sat- 1 Bakelite Rheostatt,, 30 -ohm 5 Bakelite Sockets 2 Neotrodons 12 isfaction guaranteed or Specially Bakelite 6 -ohm .001 Condenser .oard be $3 925 1 e Binding Post Strip 1 6 !&A money will cheer- priced at Complete blue-prfnta and working diagrams. fully refunded.
COMPLETE PARTS COMPLETE PARTS FOR FOR Two Stage Ultra Audion Amplifier 1000 Mile 1- $8.95 with Thordarson or Col- Tube Set... umbia Transformers; with drilled panel d with drilled panel and wir- wiring diagram $1 0.90 ing diagram.
COMPLETE PARTS FOR Randolph Special COMPLETE PARTS Reinartz Headphones FOR 5 -TUBE SUPER -HETERODYNE 1 -Tube Reln- 0.45 2260 -Tully or 2 Bakelite e -ohm Rheostats 1 cable for connect- $'J 2 23 -Plate Bremer Multicord -P Ohm $2.45 Duplex Low Loss Con- 2 Bakelite 30 -ohm ing batteries artz Set.... A densers. 1 Bakelite Potentiometer, 400 1 7x30x'.f Drilled Bakelite Inter- Panel 3 -Tube Rein- 3000 3 Remier or Columbia artz Set.... 17.55 Ohm 2.95 mediate Frequency Trans- 1 CaortereraDouble Circuit Jack 1 Baseboard formers. 1 DubUier 1 mid. Condenser 35 ft. Hook-up Wire 1 Remier or Columbia Tuned I .006 Mica Condenser 2-41n. BakeliteJ Circuit Transformer 1 .0005 Mica Condenser and 2 Dials 1 Special Oscillator Coupler megohm Grid Leak 2 415 volt C 3 .0025 Mica Condensers 1 Midget Condenser Posts Batteries 8 Bakelite Sockets 10 Binding wiring diagrams, base 2 Thordarson or Columbia A.F. 1 .00025 Mica Condenser Complete 1 Terminal Strip for board layout, blue-prints Tra nsformers Bakelite and instructions. 1 Connecticut Filament Switch Binding Posts 't COMPLETE Easy to Build Your Own Radio Set PARTS FOR All complete parts for sets on this page consist of standard advertised guaranteed parts and Include drilled bakslite panels and wiring diagrams for easy set construction. 5 -Tube Everything guaranteed on money -back basis. All transpor- Improved tation charges paid. Don't forget! Only genuine guaranteed parta used. Lack of space does not permit us to itemize individual Cockaday parts, but You are fully protected by our money -back guarantee. Our Service Division Is behind you. Receiving BIG MONEY SAVING Set COMPLETE PARTS FOR 3 -TUBE With Resistance RADIO CATALOG Coupled FREE Amplification Cockaday Receiving Set containing a thousand bargains of everything on radio-parts, also a mine As designed by supplies, complete parts for Mete. complete sets, etc., 1 Cockaday Coll 1 Grid Leak and Mica Cond. of very latest information on all different circuits, complete list of L. M. Cockaday. broadcasting stations, and other valuable, up-to-the-minute radio Including drilled 2 23-Plate Hy-Grade Cond. 7 Switch Points. 2 stops. data. Send your name and address on a Card or letter. We will panel and wiring dia- 1 Bakelite Rheostat. 6 ohm. 1 Bakelite Binding Poet Strip send Catalog free. gram complete, ready Posts to wire. 2 Bakelite Rheostat, 30 ohm. 7 Binding 3 Bakelite Sockets 1 7z21x',y in. Drilled Bakelite Free Service Department Panel Our radio engineers will help you solve all your radio problems. 1 high ratio Columbia or Thor- information on set construction. opera- $3965 darson Transformer 3 Bezels and furnish up-to-date 1 Baseboard service Is free to our customers. 1 Single Circuit Jack tion and improvement. This 1 switch lever 1 low ratio Columbia or ThOr- 24 ft. Hook-up darsos Transformer Wire $1995 2 Double Clrctilt Jacks Completeblue-prints and wiring RANDOLPH RADIO CORPORATION 2 31n. Bakelite Wale. diagrams. 159 N. Union Ave. Dept. 338 Chicago, Illinois 1 -Tube Sat.. ... $10.45 964 Science and Invention for February, 1925
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Your own name here If you are a dealer check here. Address City State Science and Invention for February, 1925 965
G. Melrose nov makes 5400 a month because 13. & 3. and r Lincoln Tech. tralnc4 him r rigit.
G. Fhlds funned from 535 a manth to superstendent or a b i g electric* Plant with i big .a airy In- creases to data oa
.aR Unholz and Farina. once common laborers. now hare their own electri- cal company. -- y I ee s Then YoullBelleadq forTheseBii
ELECTRIC ^ : JOBS Just 20 weeks. Think of it. And yet in this short time you now can receive the amazing training of the S. & H. Engineering Company and Lincoln Institute of Technology and be ready to step into big jobs like Unholz and Farina, or G. Melrose, or G. Fields and hundreds of others. And yet this remarkable course takes only 30 minutes a day. No matter what your experience or education, this is an amazing opportunity for you.
S. & H. Fits You for Jobs And Electricity . needs you. land easy course. Learn what elec- Like These Right now hundreds of big pay tricity holds for you. Find out jobs want men. But you must be what the S. & H. Training will Jobs like these above can be trained right. The experts of do for you. Also about our big yours, so thorough is this train- know exact- free Employment Bureau. But and this great institution ing. After many years' study need to fit you for do not delay. Mail the coupon there has ly what you experimental work these jobs. And you get it right now. this remarkable been developed in your own home, so simple and way of teaching electricity right easy to grasp is this amazing CO. in your own home. This shop S. & H. ENGINEERING training. You can soon be equip- In Affiliation With Lincoln type home training is an exclu- "Tech" You ped to demand and get the high sive copyrighted feature. salaries this profession pays. All it nowhere else. And re- I422 W. Monroe can get you need do is to take the first receive a Street member! You diploma step. Chicago, 111. actually certified and endorsed Arlo GeV - 1F.e9rrferfub.r by the Lincoln Institute of Tech- Send for Big Book FREE Dept. B-2 .é E7~-r<:t, nology. This is something you re- ceive nowhere else. You not only If you want to be an electrical get theoretical knowledge of expert send the coupon at once. Chief Engineer, S. & H. Engineering Co., electrical principles that is All who send immediately will 1422 W. Monroe St., Dept. B-2, Chicago, III. taught in technical universities, receive an amazing free offer of Please send me catalog and full information a a outfit of electrical ap- about the remarkable S. & H. Course. your Free but you get the practice that complete Ontfit. your Employment Bureau, etc. This in- doing prac- paratus, instruments and appli- formation is free and does not obligate me in man gets only from way whatsoever. this ances and any tical work. This makes for experimental prac- Name the tical home shop work. Also our amazing training quickest Address in big gives you infor- and yet the simplest training catalog full State electricity ever devised. mation about this amazing rapid City 966 Science and Invention for February, 1925 s5unnier1andNOWbe1ow the Mason D1xor Line. /11.1.11,11411-41 -and it's far easier and cheaper to get to the Summerland than most people think. _ ,, ;alaugllU" Those of you who store your car all winter and store your- hlllllllii. ,lo , Jtl1p selves in super -heated living rooms for six months are missing iIIIlII11G1101111Ii1 ,Illillll,J1111I some mighty good times. I, Iiliiii, III iu Get that car of yours out. ' Read MOTOR CAMPER & TOURIST and then write us for-any further information and get your car moving toward the good old Southland. You will enjoy every minute of the time and get a "kick" out of each and every day on the road. Don't forget to write us for any information you" desire. -.. -
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.....11:1 ' , 4 .- 25c -.:. ' , i V. 1 The Copy J i _ty . SOLD ON ALL NEWSSTANDS ,_ ...- , O'!ji Published by The Experimenter Pub. Co., Inc., 53 Park Place, New York, N.Y. Science and Invention for February, 1925 967
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e E. uickest Way to Make BIG Money is to IN VENT
Invention is the easiest way to earn a fortune. Almost overnight poor men have become wealthy through their ideas. Little things have brought their inventors millions of dollars. New book tells how 15 famous Inventors teach the secrets of successful Invention. Write for this book today-FREE! you by 15 THERE'S just one profession where Teach You damental facts which are given Fifteen Great Inventors without dis- everybody has an equal chance to be- great inventors. Without effort, Successful Invention least use of time and come successful. That is Invention-the Secrets of couragement, with the through this absorb- wonderful profession of opportunity and great inventors have joined togeth- money you can acquire Fifteen home -course, all the secrets wealth. College man and immigrant; office er to tell ambitious men and women the ingly interesting and used by every successful inventor. manager and mechanic; from the King of secrets of successful invention; to train them known England to a 17 -year -old farmer's boy-men in the habit of thought and Everything Explained and women of every age, class and degree action that will enable them I FREE BOOK of education have won fame and prosperity to produce practical, money- LITTLE IDEAS THAT In New through invention! Your chances to win suc- making inventions. MADE FORTUNES The Bureau of Inventive Science you all the knowledge cess are as good as anybody's BECAUSE now offers No special knowledge of flow mould you like to be the In- and experience which these fif- ANYBODY WHO THINKS CAN IN- Safety Razor. have put into their mechanics or science is neces- ventor of the Gillette teen inventors VENT! who makes TWO .AND ON F, -HALF instruction. A wonderful hook sary. No matter who you are MILLION DOLLARS a year? explaining this course will be Even the greatest inventor of all agrees or what you do, these fifteen Wouldn't you gladly be the Inven- sent to you free. Find out how fastener whose pro- that men and women can be taught to be- inventors will take tor of the snap you can learn the secrets of suc- famous fits were so big that he paid an in- cessful invention. Learn how you come successful inventors. Read the words you from the ground up come tax of $29.000? Wouldn't can become an inventor, how you Mares of Thomas A. Edison, the wizard of elec- the whole field of in- you willingly change with can turn a simple idea into a for- through inventor of the President Sus- tricity: "Invention is a science and should be vention. They will tell you the tune. Learn how 15 inventors penders now worth $5.000.000? teach you the Science of Inven- and made of taught as a profession." WHAT TO INVENT Inventors have thousands tion in a remarkably short time HOW TO INVENT. They dollars from such common things right in your home. Get this You can't doubt this great man's word. as the crimped hair -pin. the metal explain the four great steps great book now. It costs you And your belief must be strengthened when tip shoe-laces, the paper safety nothing, so write for it today. of invention-how to origi- match, Use ordinary wire paper you know what our greatest inventors were The Bureau of Inventive Science nate ideas, how to develop clip. is not connected with patent at- before they invented anything. Simon Lake you have had Ideas ideas, how to protect ideas, Surely often torneys, promoters or manufac- was a schoolboy. Alexander Graham Bell for Inventions just like these. It turers. Its only purpose is to how to exploit ideas. You may be a new toy for your children. forward -looking was a teacher. Edison was a telegrapher. The man who tnventtvl the Kiddie- teach ambitious, learn how successful inven- Kar made over $5.000.000. It Is men and women the facts that Gillette was a traveling salesman. Others as tors work, the materials they reported. It may he a new kind of can help them make money in- were office clerks, mechanics, farmers, ped- soap. It. T. Babbitt la worth mil- ventors. NOW-send the coupon. use, where and how they get lions of dollars today Even so dlers, housewives. Yet they all became in- simple information, the short-cuts a thing as a common wooden of Inventive Science ventors! wedge to stop the wobbling of tables Bureau they practice. and rhalrs (which millions of people Wisner must have thought of) has brought Building But just as important as the wmnan oho DID something Invention Easy to Learn with her idea a Dept. 72 Rochester, N.Y. these things, you also learn respectable f n r - There's nothing more needed to prone that how to sell your inventions, time. how you already have in you the ability to invent. how to get royalties, to Bureau of Inventive Science, Dept. 72, Right now you possess ideas which can make get the most money for your Wisner Building, Rochester, N. Y, you famous, bring you comfort and ease, earn ideas, how to protect yourself from the tricks for you prosperity undreamed of. All you through which thousands of inexperienced in- Please send me, without cost or obligation, need now to make your ideas worth big money ventors have been defrauded of their re- your new book, "The Science of Invention," how 15 inventors teach is to develop your inventive ability, to train wards. explaining fatuous me at home the secrets of practical invention. your mind to think inventively. Just think of what you can get in tnis re- Sci- How can you do it? Learn the science of markable home -instruction in Inventive Name Age... invention! And now, for the first time, you ence. Thousands of inventors before you have can actually learn invention-exactly as you labored for years, have struggled through Address learned to do your present work; exactly as discouragement and failure, have wasted others learned their jobs. their savings just to learn the few simple, fun- City State 968 Science and Invention for February, 1925 SPECIAL WINTER SUBSCRIPTION OFFER
- - '1 ,_.,.. .a.. aruáScience MKPRIMMTER invention p nrnuf xieporur .e eoap
EVERY DAY WINTER, RADIO'S LEADING THE EXPERIMENTER MOTORING PRACTICAL SCIENCE SUMMER, AUTUMN MAGAZINE FOR EVERYBODY AND SPRING ILLUSTRATED Everything that The EXPERIMENTER Is This magazine is dedicated to is worth- the vast army of campers and while in the radio industry SCIENCE AND INVEN- probably the most -novel mag- appears in RADIO tourists who want to know NEWS. TION is a sensation-the azine of its kind ever con- how where to go. The most popular new and The cir- first scientific magazine in ceived. It is personally edited interesting a n d instructive cuits are fully described and which the illustrations and diagrammatically by H. Gernsback, who found- article. photos, and sketches illustrated. captions tell a complete story. each will help you to The latest notes ed month from the Explains and illustrates every the old "Modern Elec- decide correctly these most. broadcast - stations are com- latest development in the field trics" as well as the "Elec- important points. mented upon. New radio of science, invention, mechan- equipment trical Experimenter," knows It covers articles on almost of every descrip- ics, radio,- in an entirely dif- every can tion is displayed outdoor sport that together ferent and decidedly original thoroughly what his readers be in while Motor with reports of novel sets indulged and way. want and have s c, as 1 when unusually successful radio wanted for Camping, u h hook-ups. many years. The EXPERI- Mother, Dad, Sister and Every important Published for the layman, in Brother and the kids swim, advance in radio broadcast or pictures so that every feature MENTER covers electricity, reception in hunt, fish, golf, hike, snap any part of the can be easily understood and chemistry, and radio, eclips- photos, play tennis, climb world is fully written up. In quickly grasped. More inter- in a word, ing the best that was ín mountains, listen on their RADIO NEWS cov- esting, twice as much edito- camp radio, and otherwise in- ers everything big, active and rial matter, more attractive "Modern Electrics" and worthwhile dulge in their innumerable in the radio field. than ever before. "Electrical Experimenter." pet hobbies. This Book F R E E- With everySubscription- TO ANY ONE OF THESE FOUR PUBLICATION
Chock full of radio con- The "Radio News" Ama- structive and instructive teurs' Handibook contains articles from cover to 224 pages. It is a verita- cover. Sections include ble modern textbook on articles on Receiving Sets radio. It is compiled by a n d Sundry Aparatus, the most eminent radio Transmitters and Acces- experts. There are over sories, R a d i o Theory, 375 illustrations on com- Vacuum Tube Data, and plete mounted sets, circuit Practical Hints for the diagrams, graphs, photos Amateur. Serves as a of special parts, etc. The ready reference a n d full size is 6 x 9 inches should find a place in the and it is bound with a library of every amateur. beautiful color cover.
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(shown above) 1.00 (on this offer) . $2.50Handibook TOTAL $4.00 YOU SAVE $1.50 TEAR OFF ON THIS LINE AND MAIL WITH CHECK OR MONEY ORDER
EXPERIMENTER PUBLISHING CO., INC., 53 Park Place, New York City. Gentlemen:-I am enclosing $2.50 for a special Winter subscription to RADIO NEWS SCIENCE & INVENTION The EXPERIMENTER MOTOR CAMPER & TOURIST It is understood that I will receive one RADIO News Amateurs' Handibook free of charge postpaid. NAME CITY ADDRESS STATE Science and Invention for February, 1925
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1 &71.1w E,fun(loiiE r , t -.--- .. -. /11, , EtEC1Ñlc r :. 11 1 a,'f01GAN -_ ;hi; J ? l L. Esw i Herbert Dickerson, Automotive Electricity pays W. E. Pence. J. R. Morgan. Columbus. Ohio. makes $30 Warrenton. Va., Albany, Oregon, over $9,000 a year to $50 a day makes $7,500 a year in business for himself t,. trical ,? iri Big D I ainYou at Home 1;: To rill a Big Pay Job It's a shame for you to earn $15 or $20 or $30 a week, when in the same six days as an Electrical Expert you can make $70 to $200 a week-and do it easier-not Electricity- work half so hard. Why then remain in the small -pay game, in á line of work that offers no chance, no the World's big promotion, no big income? Fit yourself for a real job in the great electrical industry. I'll show you how. Big PayField Electricity is the field of Be an Electrical Expert the greatest opportunities.. In all other trades and professions competition is Earn $3,500 to $10,000 a Year so keen from over -crowd- ing that only the excep- Today even the ordinary Electrician- the "screw drive?' kind-is making money-big money. But tional man can get to it's the trained man-the man who knows the whys and wherefores of Electricity-the "Electrical the top. Expert"-who is picked out to "boss" the ordinary Electricians-to boss the Big Jobs-the jobs that Not so in the Electrical pay $3,500 to $10,000 a Year. Get in line for one of these "Big Jobs" by enrolling now for my easily line. learned, quickly grasped, right -up-to-the-minute, Spare -Time Home -Study Course in Practical Electricity. Here is a profession that It's this Service that makes "Cooke" training different is fairly bubbling with Age or Lack of Experience from any other training. It's this Service, plus "Cooke" possibilities - with thou- No Drawback Training, that makes the "Cooke" Trained Man the sands of chances for won- You don't have to be a College Man; you "Big -Pay Man," everywhere. derful success. We stand don't Be a "Cooke" Trained Man and earn $12 to $30 a day- today on the very thresh- have to be a High School Graduate. As Chief $70 to $200 a week-$3,500 to $10,000 a year. old of the real Electrical Engineer of the Chicago Engineering Works, I Age-an Age when every- know exactly the kind of training you need, and Get Started Now-Mail Coupon thing now operated by I will give you that training. My Course in Elec- I want to send you my Electrical Book and Proof Lessons steam or gas or horses, tricity is the most simple, thorough and success- both Free. These cost you nothing and you'll enjoy them. will be moved by Electri- ful in existence, and offers every man, regardless Make the start today for a bright future in Electricity. city. But it is an Age de- of age, education or previous experience, the chance to be- Send in Coupon-NOW. manding specialists- come, in a very short time, an 'Electrical Expert," able to trained men - Electrical make from $70 to $200 a week. L L Cooke, Chief Engineer Experts. Such men can Electrical Working Outfit easily earn from $12 to FREE FREE Chicago Engineering Works $30 a day. With me, you do practical work-at home. You 2150 Lawrence Ave., Dept. 22 Chicago Money is being poured into start right in after your first few lessons to work the Electrical Industry at the at your profession in the regular way. For this you need rate of n billion dollars n tools. and I give them to you absolutely free-a whole kit, year. Think of it-a thou- a complete outfit, one that would cost you $12 to $15. Use this Free Outfit Coupon! ' . sand million dollars a year for electrical expansion. This Your Satisfaction Guaranteed ' L. L COOKE, The Man Who Makes' means-men-jobs-oppor- Dept 22 "Big tunities. So sure am I that you can learn Electricity-so -Pay" Men sure am I that after studying with you, '2150 Lawrence Ave., Chicago My book me, too, Dear big the "Vital Facts" can get into the "big money" class in electrical work, that I Sin Send at once, Sample Lessons, your Big II of the electrical industry and will guarantee under bond to return every single penny paid Book, and full particulars of your Free Outfit and the wonderful opportunities me in tuition, if, when you have finished my Course, you Home Study Course, also the Free Radio Course-all that await "Cooke Trained are not satisfied it was the best investment you ever made. fully prepaid without obligation on my part. Men" tells you all about this Big Pay Field. Guarantee Backed by a Million Mail Coupon Dollar Institution ' Name. Back of me in my -guarantee, stands the Chicago Address for the Free Engineering Works, Inc., a million dollar institu- ' Vital FACTS tion, thus assuring to every student enrolled, not only a wonderful training in Electricity, but an unsurpassed Stu- I Occupation dent Service as well. -----1í------The`Cóoké'Tráin_ed Man iithe `Bzg.Páy'1Min 970 'Science and Invention for February, 1925
TeEXPERIMENTER an open sesame to the great undeveloped field of inventive opportunity RADIO
has tremendous possibilities for every experimenter. In fact it has been only by constant inventing and research work on the part of many engineers and designers that radio broadcasting has come into existence. Opportunity knocks at everyone's door today-Radio has a hundred prob- lems waiting for you to solve. EXPERIMENTING The EXPERIMENTER, the one and only magazine expressly for the person who experiments, carries each month many pages of radio that as a PROFESSION t'atail the major problems of the industry that are waiting to be solved. The EXPERIMENTER covers completely the field of radio from the By HUGO GERNSBACK standpoint of the development of the industry. The following extracts from Mr. Gems - back's editorial in the JANUARY issue of _ the Experimenter will give you an idea of the ~ o o o o o o possibilities in store for the radio experimen- ter. The EXPERnRERTER Th. EXPERImE ITER The EXPERIME ITER' Radio Data Sheet., Radio Dele Sheet. Radio Data Sheet "Many of our readers experiment as a sort e, .o...... r y... rum. S. s.i... w.... of hobby, for pleasure or instruction, but com- paratively few realize that an experimenter more r.rarne..o rtrgeeece .n¢ unite o, e,r "Th_é: yt ( BURIED ''`, = \,' TE AS UP ' E can still be found in CHEMISTRY food Chemists Command High Salaries and you can make yourself What Some of Our Students Say of This independent for life by un- Course: I harp not written since I received the big J earthing one of chemistry's set. I can still say that It far exceeded my tÁ-, r+ anticipations. Since I have been studying with your school I have been appointed chemist for yet undiscovered secrets. the Scranton Coal Co. testing all the coal and ash b."s proximate analysis. The lessons are helping 'me wonderfully, and the interesting Do you remember how the tales of pirate gold used to fire way le which they are written makes me wait patiently for each lesson.-MORLAIS COUZ- your imagination and make you want to sail the uncharted ENS. seas in search of treasure and adventure? And then you I wish to express my appreciation of your prompt reply to my letter and to the recom- would regret that such things were no longer done. But that mendation to the General Electric Co. I In- is a mistake. They are done-today and on tend to start the student engineering course at everyday-not the works. This is somewhat along electrical desert islands, but in the chemical laboratories throughout lines, but the fact that I had a recommenda- 1 your own tion from a reliable school no doubt had con- country. Quietly, systematically, the chemist works. siderable Influence In helning me to secure the His work is difficult, but more adventurous than the blood- job.-H. VAN BENTHL'TSEN. curdling deeds of the So far I've been more than pleased with Spanish Main. Instead of meeting an your course and am still doing nicely. I hope early and violent death on some forgotten shore, he gathers to be your honor graduate this year.-J. aL T. O'CONOR SLOANE,\ wealth and honor through his invaluable to NORKUS, dB- contributions hu- / find your course excellent and A.B.. .M.. LL.D.. Ph.D. . your Instrue. manity. Alfred Nobel, the Swedish chemist who tlon, truthfully, the clearest and best assem- Noted Instructor Lecturer and invented Author. dynamite, made so many bled I have ever taken, and yours Is the fifth Formerly rrreasurer, Ameri- millions that the income alone from one I've studied.-JAMES J. KELLY. can Chemical Society and is practical his chemist midi many well known bequests provides five $40,000 prizes every year for the From the time I was having Chemistry It achievements to his credit. Not advancement of science and peace. C. M. Hall, the chemist has never been thus explained to me as It is only has Dr. Sloane taught chemis- now. I am recommending you highly to my try for years but he was for many who discovered how to manufacture aluminum made millions friends, and urging them to become members ryears engaged in commercial of such an organization.-CHARLES BEN- work. through this discovery. F. G. Cottrell, who devised a valu- chemistry able for JAMIN. process recovering the waste from flue gases, James I shall always recommend your school to my Gayley, who showed how to save enormous losses in steel friends and let them know how simple your les- manufacture, L. sons are.-C. J. AMDAHL. H. Baekeland, who invented Bakelite-these I am more than pleased. You dig right in are only a few of the men to whom fortunes have come from the start. I am going to get somewhere with this course. I am so glad that I found through their chemical achievements. You.-A. A. CAMERON. I use your lessons constantly as I find It more thorough than most text books I can secure.-WJf. IL TIBBS. Now Is the Time to Thanking you for your lessons, which I find not only clear and concise, but wonderfully interesting. 1 am-ROBT. H. TRAYLOR, Study Chemistry I received employment in the Consolidated Gas. Co. I appreciate very much the good service Not only are there boundless opportunities for amassing of the school when a recommendation wealth In Chemistry, but the profession affords congenial was asked for.-JOS. DECKER. employment at good salaries to hundreds of thousands sebo merely follow out its presort applications. These appli- cations are Innumerable, touching intimately every business and every product In the world. The work chemist can be of the hardly called work at all. It Is the keenest and most enjoyable kind of pleasure. The days in a chemical laboratory are filled with thrilling and delightful experimentation, with the alluring prospect of a discovery that may spell Fortune always at hand to spur your enthusiasm. / ' ' You Can Learn at Home To for lids / qualify remarkable calling requires elaborate apeciallxed training. Formerly it was necessary to attend a university for several years to acquire that training, but thanks to our / highly perfected and thorough system of instruction. you cart now stay at home, keep your /CHEMICAL position, and let us educate you In Chemistry during your spare time. Even with only common schooling can take you our course and equip yourself for Immediate Practical work in a chemical / INSTITUTE laboratory. Dr. Sloane gives even' one of his students the same careful, personal super- vision that made him celebrated throughout his long career as a college professor. Tour /OP NEW YORK .t Instruction from the very beginning Is made interesting and practical, and we supply Home Extension with you apparatus and chemicals for performing the fascinating analyses and experimental' Division 2 work that plays such a large part in our method of teaching, and are awarded ' you the 66 -S--West Broadway Experimental Equipment Institute's official diploma after you have satisfactorily complete.] the course. ' New York City Easy Monthly Payments Furnished to Every Student You Please send me at ones. don't have to have even the small price of the course to start. You can without any obligation on me pay for It lis We give to every student without additional charge this email monthly amounts-so small that you won't feel them. part, your free Rook "Opportuni- The cost or our course is very lose, and includes everything. even ' equipment, forty-nine of the / ties for and - chemical including pieces labora- Chemists." full par chemistry are no extra% to tory apparatus and supplies, and forty different chemicals outfit-there buy with our course. Our plan titulars about the Experimental Equip - and and of monthly payments places a chemical education within the reacts of /ment reagents. These comprise the apparatus chemicals A. given to every student, Also plea.. used for the work of course. Tire fitted everyone. Write us and let us explain our Plan In full-give us the me about plan of and experimental the opportunity of showing how your payment heavy wooden box only as a case for the outfit you you can qualify for a highly trained your 30 serves not without oven special day offer. taut also as a useful laboratory accessory for performing technical Doaltion giving up your present employment.' countless experiments. Special 30 Day Offer Resides furnishing the student with his Experimental Equipment, we aril making an additional special offer for NAME a short while only. You owe It to yourself to find out ; CHEMICAL INSTITUTE about it. Write today for full Information and free book "Opportunities for Chemists." Send coupon / the right now while it 1s fresh in your mind. Or just /ADDRESS OF NEW YORK, Inc. write your neme and address on a postal and mail Home Extension OIvislon 2 It to us. But whatever you do. act today before this offer is withdrawn. 66.S-WEST BROADWAY NEW YORK CITY DON'T WAIT-MAIL COUPON NOW% /CITY STATE 5.1., Feb. '25 972 Science and invention for February, 1925 e. Master Electricity trill-- By M Í YR A ,y Actual J Practice ; The only way you can become an expert is by doing the very work under competent instructors, which you will be called upon to do later on. In other words, learn by doing. That is the method of the New York Electrical School. Five minutes of actual practice properly directed is worth more to a man than years and years of book study. Indeed, Actual Practice is the cnly training of value, and graduates of New York Electrical School have proved themselves to be the only men that are fully qualified to satisfy EVERY demand of the Electrical Profession. The Only Institution of the Kind in America At this "Learn by Doing" School a man acquires the art of Electrical Drafting; the best business methods and ex- perience in Electrical Contracting, together with the skill to install, operate and maintain all systems for producing, transmitting and using electricity. A school for Old and Young. Individual instruction. Over 9,000 Graduates are Successful Men in the Electrical World No previous knowledge of electricity, mechanics or mathematics is necessary to take this electrical course. You can begin the course now and by steady application prepare yourself in a short time. You will be taught by practical electrical experts with actual apparatus, under actual conditions. The N. Y. E. S. gives a special Automobile Ignition Coarse as an advanced training for Auto Mechanics, Garage Men and Car Owners. The course covers completely all Systems of Ignition, Starters, Lighting J and other electrical equipment on automobiles, motor boats, airplanes, ._ v etc. Let us explain our 9 complete courses to you in person. If you can't call, send now for 64 -page book-it's FREE to you. New York Electrical School 29 W. 17th St., New York, N. Y. Please send FREE and without obligation to New me your 64 -page York book. NAME STREET Electrical School CITY STATE 29 West 17th Street, New York © Volume XII Feb., 1925 %Whole No. 142 y No. 10 ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,..,.,...... ,.,.,.,,,. ' . . © r V; H. GERNSBACK, EDITOR AND PUBLISHER H. WINFIELD SECOR, ASSOCIATE EDITOR T. O'CONOR SLOANE, Ph.D., ASSOCIATE EDITOR Editorial and General Offices, - - - 53 Park Place, New York "Those Who Refuse to Go Be and Fact Rarel Get As Far As Fact" HUXLEY NeecTed linverzfi®ns By HUGO GERNSBAC VERY so often we run across some new little item that lem. The writer does not know whether silk was ever tried, but seems to be in everybody's household, or in everybody's there must be some material that can be made, to stand the wear; possession, and often the inventor of the article has reaped or perhaps an arrangement might be invented hereby a new edge a small fortune, and sometimes a big one, from the idea. could be inserted by ,the 'laundry people every time the collar is And ever so often, the writer receives requests from readers laundered; because we all know that it is not the entire collar that who wish to know on what they should try their inventive ingenuity, wears out, but only the edge. Hence, we have.to throw away collars in order to devise something of use and merit. 99.5% in good condition, simply because a small fraction has worn There are, of course, many thousands of things that can be in- out. vented, by almost everyone, during the year. The difference between WINDOW CLOSER. Your wife and you take a stroll along inventing an article and putting it on the market and selling it suc- the avenue, or you are visiting at your friends, when suddenly, for cessfully is usually found in the practi- no reason at all, it starts to rain. The cability of the device and how much it is lady of the house immediately gets a case actually needed and wanted by people. of nerves, because she remembers that 1 BELIEVE 3 PENCIL ERASER. This is a good the parlor window has been left open, I BELIEVE THAT: illustration of the above. Everybody and, sure enough, the rain is coming from THAT: be a good in- To makes mistakes, and everybody, there- that side. The pew sofa" and the new the prime requisite i ventor you must be fore, needs an eraser badly. The man rug will certainly be ruined. This hap- o f the inventor 1 an excellent ob- who invented the rubber eraser most pens to all of us, but so far no inventors must be everlast- server. assuredly was a genius of the first cali- have thought of and constructed a prac- ing perseverance. bre. And while the rubber eraser still tical automatic window closer that shuts .,,,.,.,.,,,,,,»,,,,,,,,,,,,,,,,,.,,,,...,,,,.,,,....,..,. I persists and will be used for many years down immediately the rain starts falling. to come, we need today a different sort of an eraser, for several To be sure, there have been patents of this kind galore, but some- reasons. Where black lead is used, the rubber eraser is excellent, how or other they could riot have' been very good, because the idea we now into an find but are coming era of colored pencils, and we has never been adopted in practice. First, the article has to be no longer that the rubber eraser serves. Try to use the rubber cheap, so that anyone can install it for any window. Second, it eraser on colored pencil lines and you usually make a mess of it. must always be ready to act; and third, it must not take up a great Furthermore, the fountain pen is now used almost as much as, or deal of space. There have been proposed articles of this kind con- perhaps more than, the pencil. No one has as yet succeeded in structed with thin blotting paper or tissue paper, the idea being making a good and simple fountain pen or colored pencil eraser. that as soon as the water' softened these, a trip would immediately What is needed is a simple chemical or mechanical eraser to cover release and a weight would close the window. The trouble with these two crying needs. some of these devices was that a strong wind would UMBRELLA SUBSTITUTE. Before you leave do the same thing. Here is a good item which, when your home in the morning, your daily paper assures worked out satisfactorily, should be used by every house- you that it will be fair for the day. But when you holder the 1 BELIEVE world over. come from lunch, you find that it is raining "cats and BILL RENOVATOR. It costs the United States dogs." Of course, you have no umbrella, not having THAT: Treasury untold thousands to renovate our paper money anticipated rain. So you stand under a doorway and in time to come, bills every year. Most of the bills are really not so wait for the rain to stop-which it may or may not inventing will be old that they could not be cleaned by some chemical do. So you skip through the rain and arrive at the recognized a s a or mechanical means, and every bank would welcome is remedy? office soaked to the skin. What the There regular profession. such a machine. You put the dirty, crumpled ten - should be a simple, light contrivance that can be placed dollar bill in one end, and out it comes, laundered. in the inside of every hat, or carried conveniently in crisp and like new from the other. To be sure, there the pocket. It can be made of oiled or prepared silk are some such machines in existence, but seemingly in such a manner that, when unfolded, it will cover one from head they have not been entirely successful, because as yet not every to foot. Being transparent, we can look through it and see where bank uses them. The machine the writer has in mind should be we are going. The article would have the shape of a huge rubber a simple affair that could be sold for less than $50. It would con- finger, such as you buy in drug stores, big enough to cover your tain a chemical tank in which the bill is soaked, then another cleans- hat and go down to the ankle. It would cover the arms as well. ing tank through which it is run, finally to emerge, clean and dry, It should sell for about $2, and need not weigh more than two after being ironed out by two electrically -heated rollers. The whole ounces. machine need not be larger than a foot square and a foot high. COLLAR PRESERVER. When your collars come back from There is a demand for such a machine. the laundry, you feel, as a rule, like selling them to your hardware ADVICE. The thing that the inventor should bear in mind when store, because the edges make excellent saws. he becomes imbued with a new idea is that A recent laboratory report shows that we it is one thing to have a good idea. and do not wear out our collars. Instead, the guile another to patent that idea and make laundry wears them out for us. It would THE GOLDEN AGE OF money out of ít. Before spending hard- seem that in up -turned or turn -downed col- SCIENCE earned money on models and development of lars the constant bending and unbending and a given idea, the would-be inventor should is running of the collar between hot launder- now symbolized by the golden first find out what has been accomplished in ing rollers breaks the fabric at the edges cover of SCIENCE & INVEN- the same line before. The easiest way to hence the saw edges. This is where our TION, LOOK FOR THE GOLD do so is to get in touch with a good patent inventors should get busy. A reinforcement attorney who. COVER every month! for a small sum, will be glad of some sort, in a different kind of material to make a patent search among similar de- from linen, would, perhaps. solve the prob- a1111111,...1.,,,,,,,,,,,,,,, ..... ,.,,,,,,.,,,,,,,,,,.,..,,.,,,,,,,,,,,,,,,.,,,,,,,,,,,,,,,,,,,,,,..,,,,,,,,,,,,,,1,1,,,..,.: vices. This always saves money in the end. 973 974 Science and Invention for Februart, 1925 aaShIpwTecne 0 on 5tage By A. P. PECK ! MAIr, STACK AND / ,rVENTI; TORS FALL / /! 1 , ` / +qf ,/ / / I[t v" , , 111/11 , ! /) YELLOW AND RED A i I . ti....d FLICKERING LIGHTS/ / I I -ON TRANS - Í.' PARENT / FLAMES / B.RI,DGE MUSLIN , , SSILK STRIAMERSi TILTS BAC.K,. ¡ % o DROP _ _ ; II "Tr ¡, i....;~,....=-----=':: _; I:,e 11_ , << _c:T:OJ . - . -..---.,...... _=----- . I. .q - - / / .roll r =...... i 4 t: r r [ i#= t d .',r.. tt¡? t rrt:_ .`:y . or k ~. T -;./~~15.' o' UNDER. -----k -- . _.,STAGE FLOOR. WAVE 4VA V E.. ; -RED LIGHT; í1 PRO EC PROJECTOR ° TINTS STEAM ' TOR. - , i .. - - AIR :.r COMPRESSOR \o-:' ' ELECTRIC STEAM 1' 's BOILER BELLS 3 WHISTLES h ,. -- _.,.- - . r< :- _..r.s ljSSOR a( GUN GIVES EXPLOSION FOR forty-eight hours fire has been raging in the lower hold of the EFFECT SS. Corsica[. The Captain of the vessel, making violent and unreciprocated love to the heroine, is knocked out in the tussle. A member of the crew enters in haste--the fire has broken through the deck and is rapidly spreading! ,brJo- The Captain is needed on the bridge but lie is in no condition to take charge. Signal whistles blow, gongs ring and bedlam breaks loose. Flames burst from the bridge and creep up the decks. An explosion! The smoke stack and ventilators crumble. More flames-smoke and fire burst through the floor of the cabin. The gongs and whistles repeat their clamorous _calls for assistance. A second explosion! The entire solid wood mast in the center and totters falls WAV E to one side with a resounding crash. And all this is done on an ordinary theatre stage with theassistance of the apparatus depicted above and to the right. SOUND Langdon McCormick, well known theatrical producer, is the genius that DEVIC worked out the details of this realistic stage shipwreck, now running at the \Vallack Theatre, New York City, in the play "Shipwrecked." Using simple apparatus, Mr. McCormick has produced one of the most spectacular plays of NOISE MAKERS the theatrical season. He uses colored lights and red silk streamers to produce BACK STAGE flame effects and dry steam for smoke. The noise producers employed are illustrated at the right Science and Invention. for February, 1925 MovIle nillm DupIlIlca:1es 7IlguTes latest development in m»Lion picture THEphotography is the duplication of figures while the object .is in motion, by means of either line drawings or photographs. At the left is an enlargement of a frame of the mov- ing picture film. The man is seen to leave the spring board and go through the acrobatics of his dive. In mid-air, however, his figure remains impressed on the film, and as he passes from one movement to another, an impression of his previous positions is con- stantly maintained until the dive is over; these figures remaining in view for the sake of comparison instruct in the per- formance of the dive to a degree here- tofore unexcelled.. The photographic figures can be replaced by outline sketches, as illustrated elsewhere on ,this page. The process is a com- bination of the Novagraph or slow motion picture and Max Fleisher s cartoons. -H. Winfield Secor- / L r ) 1`. I, SHUTTER. RFlFASE MECHANISM , "/PCAMERA PHOTOGRAPHS IBI ` ch.t \ The photographs are above taken from another analysis film. In No. 1 the diver is just about to leave a spring board. As he reaches position No. 2, an outline figure remains at his first position. At any time The best golfers the diver can be made to come back from Fig. 5 6, to and continue the dive from that position. teach that the up- ward stroke of the club should be the same as the down- ward stroke. A thin line which seems to leave the club as it moves .11, indicates that the golfers do n o t The system may be used The action in the film may be repeated and reversed at any point as to combine slow motion indicated practise what they above, where a dancer leaps into the air, crosses her legs, starts preach. with a regulation speed to descend, reverses her action to the former position, and repeats. movement. Let us as- sume that we have an in- dividual making a broad jump as shown at the right. He runs at full speed to the taking -off place where his action gradually slows up until he is scarcely moving. 976 Science and Invention for February, 1925 VIlewIlng Mairl from. Mountain T©p j ., ,. le 1 , -r ` Professor Schaer (left) of I I Geneva and Professor de Quervain of Zurich had to dress in Arctic attire while observing Mars from the highest observatory in the r. 1.I world, which was specially built 11,721 feet above sea level on the Jungfrau, the famous Swiss peak. The photo . of the observatory is given at the left and the interior is shown above. It is claimed that the astronomers saw what they 't believe to be light signals on the planet Mars. Unfortunately, during the days of its nearest approach a blizzard filled the air and rendered observation difficult. Sh©©tIlng thz AIlw t® friret WIlnd By ERNEST BRENNECKE WWI WIND 1 . I ! ."`...Iy..- _. r '.P .' , te ti 1 ....,. . : J , .v' R . y '<-. .- r y J . w ~ LOW CLOUDS fifi ''_ ` I 1 en, O° I Co. ` ¡, a \ i 1 : EAST WIND ` a: I`reTrwf i , Li .b t I 1 / I / ,. .FrM I s ' tr-t`- r4 . ,1 f f _y~ 1 / r UPWARD COURSE. / RETURN OF r OF BULLET 1 BULLET TO 1 / METAL 2O0t- The British meteorological and aircraft stations have been equipped with a novel scientific gun, gun -mounting and gun -shed. When the clouds hang low in the sky. the winds above them may blow in opposite directions to those near the earth. For the p-otection of the airplane pilot, a bullet is fired into the air after the rifle has been properly set The object is to cause the -bullet o-- , to fall back upon the metal roof and the powder charges, weight of the bullet and angle of the gun are changed until it does so. By computation, the character of the wind is then determined. Science and Invention for February, 1925 977 Awa.cmattfie RziLToczcol. Cwasgfing Gaee This fool -proof railroad crossing gate absolutely prevents an automobile from getting on the railroad right-of-way when the train approaches. When the trains enters a block, a warning bell and light automatically operate on the first framework. A carrier with swinging ropes is lowered so that the ropes strike against the automobiles. 1 "1 a VD 01 115 0111::15 II I To of 11.1 vtio ,1494,4 TIL. L Itrio- fls A. The automobile illustrated on the top of this page having passed the warning ropes, meets with a steel net which has been Should la lowered in its path two hundred feet down the road. r he be unable to stop, he will not be injured by the oncoming train because, although the net yields under pressure, it is impregnable. For directing street traffic, the device shown immediately above and also to the right has been designed. This is a huge turnstile placed in the center of street intersec- tions and operated by the traffic officer by means of an electric motor. The driver cannot crash against the steel arms, but might strike the flexible ropes, .which hold him. At night the ropes arc detached and the arms elevated. -J. W. Von Stein. . _ N.Y. CIIV's ~err Supplly Shouild Wan, MG 'Kahl I RAIN o I 0 " RAIN -.., .-.. , If the water descended upon New York and With a daily consumption of approximately did not drain away for a period of one year, 740,000,000 gallons, New York City uses its average citizen would be submerged to about 270,000,000,000 gallons of water per three-quarters of his height in the water. The year. The annual water supply would about ..,., _ ,...,..:..., water consumed in one second would fill equal the volume of 422 Great Pyramids, 1- -4._.. ? eighty-six bath tubs, or one bath tub twenty each measuring 756 feet at the base. The feet long, six and a quarter feet deep and water passing over Niagara per second is g.c. .J:-.... - nine and a fifth feet wide.-C. N. Holmes. used in New York in 192 seconds. ,.___....._ z., 1,61.1,,' '7 - ... Y - I V..../ . , 1 . . 4 Bruir7 -' . :7.0 t , :"¡ .- - 7. .1." ..A ,I), r: ' - ..".- 7.... . I . / fr-41. , LL --g I.' r-- I I - - I , i li _ - u. e-.z.-2-...t.-!...2._£.r.,,,L,_ r I. g #0 ' -- - 1 , --lc - 11'.11.521'1!:1.<1 . It ,, '41 /II s 12»,.. , .0 191. , .... - 'sr ..1,..n o . . I d j, ft.- grt tt ' --- I .. Ft. ' ' k- , - . tor-«»-. .... %I Palling as rain, the water supply of New York would fill a river one _ e hundred and fifty miles long, one 614)A1k) thousand feet wide and forty-five ---(Q1924 BY &CiENC and a half feet deep.. Ek INVENTION 978 Science and Invention for February, 1925 Here we see the doctor of the future at work, feeling The Rad,fio the distant patient's arm. Every move that the doc- tor makes with the con- IL e` a y" trols is duplicated by radio at a distance. When- e¿y dy ever the patient's teledac- By HUGO GE3SBA,CR tyl meets with resistance, Member American Physical Society the doctor's distant con- 1 trols meet with the same resistance. T h e distant The Teledactyl (Tele, far; Dactyl, finger-from the controls are sensitive to Greek) is a future instrument by which it will be possible sound and heat, all impor- for us to "feel at a distance." This idea is not at all tant to future diagnosis. be with The doctor sees what he impossible, for the instrument can built today is doing by means of the means available right now. It -is simply the well known television screen in. front telautograph, translated into radio terms, with additional of him. refinements. The doctor of the future, by means of this instrument, will be able to feel his patient, as it were, a distance (see RadoopaTeiee ew at R Lóópin_ illustration to right). The vi doctor manipulates his Rampúlsésvlsion controls, which are then I Doctor's Control. manipulated at the pa- Apparatus In tient s room in exactly the . office same mabner. The doc- Radio tor sees what is going on Tela tograph, in the patient's room by "Feeler» meads of a television Patient screen. (See other cap- At Home tions on this page.) Showing how the teledactyl is worked. The impulses of the teledactyl are transmitted by Patient's radio to the patient, who, in Instrument turn, has a similar instrument, which not only receives but also 'lasnetic transmits the same impulses. In Sound solen- the- patient's room is also sta- Collector oids tioned a television transmitter, "Microphone,' which transmits the light im- Aerial pulses back to the doctor. Spring, , N ,t NI tt N2 AS our civilization pro- I IV. gresses we find it more Radio Doctor's Microphone waves and more necessary to act Circuit N2 Instrument of visit- N3 , at a distance. Instead it í1 ing our friends, we now tele- t phone them. Instead of going I Control Circuit to a concert, we listen to it by Only / v Shown An(ipliJirer (P=Pivot) radio. Soon, by means of tele- vision, we can stay right at Rheostat home and view a theatrical per- boils formance, hearing and seeing it. Rec.Loop RAerial \, This, however, is far from suffi- Ré cient. As we progress, we find Radio, a our duties are multiplied and we Transmitter t AI t ,_ less and less time to trans- pistan[Station Az ' have iw in ,r -- -' ¡ A22 port our physical bodies order o _t-_-' to transact business, to amuse ----i A3= Current Supply ourselves, and so on. The busy doctor, fifty years hence, will not be able to visit How the teledactyl operates: The tele - dactyl is but an improved telautograph; his patients as lie does now. It it works, however, in three planes, where- takes .too much time, and he as the present day telautograph works in can. only, at best, see a limited only directions. The ,is two teledactyl number . today.. Whereas the connected to a radio transmitter, "which services of a really big doctor transmits the impulses; these then are re- so important that he should ceived on the patient's instrument. These are same impulses are then transmitted back never have.'to leave his office; 604- to the doctor's instrument. The sound on the other hand,- his patients collector 'microphone is used so that the cannot always come to him. doctor at the other end can use his radio This where the teledactyl and /1/ . is stethoscope and listen . to the patient's diagnosis by radio -comes in. heart -beats. ,.- (Contbtited on page 1036) -SENDER- - RECEIVER= Another application of the Teledactyl. Here we see the man of the future sign- RI Pen ing a check or document at a distance. I- Line wires Stylus-=- .E" Spring Rack By moving the control, it goes through Rheostats. 1 exactly the same motions as he would , ,( 14A in signing the document. He sees what 1 he is doing by means of the radio tele - ` r_- The circuit of the well known telauto- R2 graph, now in hotels and banks, view in front of him. The bank or Current = used I Gears and which handwriting is other official holds the document in front Supply by means of ti Iron; of a receiving teledactyl, which is transmitted to a distance. Every time to J Gore attached a pen or other writing instru- the stylus is moved it varies the resist- ment. The document is thus signed. ance of two rheostats, which, in turn. (C)1924 BY SCI ENDE & move two solenoids at the receiving end; INVENTION these move a pen reproducing the hand- Solenoid; writing. Science and Invention for February, 1925 979 POrncQ óole ZiecfrOO canzdIlOg mph THE portable electrocardio- graph recently demon- strated by the general engi- ^ neering laborato.y of the General Electric Co. is illus- trated on this page. One of these devices could be used by the country physician in submitting a diagnosis by radio, in accordance with the apparatus depicted on the left hand page. The entire device weighs only 37 pounds and the power unit weighs 33 pounds. The apparatus open is shown at the right. - Sf\ f ,1_ o ' - e ` _ "`>. _ cs"Ss \. The photo above shows the portable electrocardiograph with the panel board inverted showing the vacuum tubes. In the old style cardiograph elaborate protection against vibration had to be made. Usually vibration -proof foundations were used for the mountings of these instruments. The fragile metal quartz thread used in the firmer apparatus is dispensed with in this construction. Contraction of the heart is muscles is accompanied A patient having a cardiogram made depicted in the above by or pieceded by an elec- photo. Simple metal electrodes fastened to the arms and legs trical manifestation. This of the patient are used in place of the wet sponge electrodes electrical change is ampli- formerly employed. The functioning of this instrument is not fied by vacuum tubes. affected by skin resistance. The results could be transmitted The voltage before and by radio to a consulting physician, telephotographically. after the heart beat is in y- the neighborhood of one . one thousandth of a volt. aL10 J. uLuOuOOo+j j...o'""/`.... Lead ,= g r .. Ir f_a [r a 9 I) Z ufU U I ead II The power unit for the electrocardiograph is illus- trated above. At the right are three typical cardio- grams used for diagnosing different kinds of heart trouble taken with three different leads. They are caused by a spot of light acting on a moving film strip. 980 Science and Invention for Februar;, 1925 Twfich. Sub-5ea By EDWIN IN the Buster Keaton comedy "The Navigator," the star appears in a diving suit beneath the surface of the sea engaged in repairing a leak in the hold of a vessel which has run aground. 'Here he has an encounter with a swordfish and devilfish. Most of the views of his performance were actually secured at a depth of twenty feet on a small portion of the bottom of Lake Tahoe with apparatus like that illustrated on this page. In the story you behold a ship drifting A out to sea with only two passengers on board, Keaton and his would-be wife. The .-A- ... ship runs aground off a cannibal island and springs a leak. It is at this time *1p that Keaton dons a diving suit and goes over the side of the vessel while the girl mans the air pump. Meanwhile savages overrun the vessel, capture the girl and cut both lifelines and air hose. Keaton at the bottom of the sea is busy repair- ing the leak with a hammer and presumably wood plugs. While thus engaged a swordfish comes toward him followed immediately by another. He grasps the first one and using it as a weapon bat- tles with the second, finally subduing it. When he realizes that his air hose has been cut, he turns off the valve at the top of his helmet and pro- . a ceeds to walk toward shore. On the screen you "shot" of Buster The above photo is real undersea behold him coming toward some rocks where the Keaton in a diving suit. The pail beside him is used for washing his hands. Sounds ridiculous doesn't it, octopus is presumably hidden. As he approaches but that is just why the picture is really funny. He the rocks, a long black arm stretches forth and away. uses a wooden mallet which floats.----0.--~ clasps the neck of the bronze helmet. The diver , tl. draws a knife from his belt, flourishes it above his head, and disappears behind the rocks as an inky black cloud floats upward. There arc signs of a struggle and a momentary glimpse of the octopus, and then the diver emerges and continues on his SET REPRESENTING ~Ph' STERN way. The cost of the picture was considerably ` GHUUNDED ON SAND BAR increased by the procuring of real undersea effects, - ARTIFICIAL SWORDFISH OPERATED FROM ABOVE BY WIRES but this helped to enhance the actuality of the scenes. The only scene taken in a tank in this picture was a close-up of a baby octopus with a five-foot tentacle spread. The photo above shows Kea- ton holding a swordfish and ready to encounter another which begins to float toward him. This is a battle to the s: CANNIBALS (UT AIR PUMP ROPE AND AIR 4 / finish. It is a good thing LINE AND , E,I % that the swordfish were con. KIDNAP HEROINE ¡ WHO NAS BEEN ID j 't trolled from above by quite invisi- OPERATING PUNS' = - ble wires. When the air hose is W cut as illustrated at the right, one BUSTER PULES IN NOSE _ - - (¡ "E AND TINOS THE END i.- ) SIDE Oi wonders how Keaton gets his air. CUT - AIR BUBBLES "- t SKID I SHAT OF REA- "HAD," A second air supply hose is coupled STOP OF pp -* ' ÁVEININEME r _ OCTOPUS TAKEN IN TANK ,I to the cut hose, and escaping air `1' -F ., /' passes through another hose. `- 'p- THIS IS DONE BY CLOSING AIR VALVE 1 t - AND USING TWO HOSES -ONE FOR I FRESH AIR AND ONE FOR EXHAUST LJr A I NG'BULB FORCES 'n CAMERA MAN ENTERS HERE ( PREss BLACK [NTRANCE Two HOSES CONCEALED IN TANGLE TO PUMP -m1. Itllh LquiD LAMP OF y OUT OF OPENINGS IN It - I I t NRINI < r, I . BODY OF OCTOPUS, pfJ tAI i 1 RUBBER OCTOPUS rI (j PARTIALLY C AND s ---e,)"1- aEHIND ROCK AND ply HOW BATTLE WITH 11 OPERATED 1505 RBOVE'.i . l OCTOPUS IS FILMED i G --- r - . .. I ,.; Y! --rill,rl cz. w .' yk- aadi }}?. ; t7 c , F " CAMERA STOPPED PERMIT M * - r L7 I IF RUBBER ARM PLACING OF f 'M ¡ Il . AROUND HIS -NECK `(,E, ord y ' / AIR HOSE IS SUPPOSED TO BE I 1P26 BY CUT:- REALLY IT IS CON. 4t"]EYC6 Fil,tIT:trTIGLti CEALEO 8Y WATER AND GOES BACK TO PUMD ON BEACH r T In the octopus scene a "shot" of a real live octopus in a tank was taken, From this scene the scene was cut to the under water shot, where the diver battles with an octopus. This time, however, the octopus was artificial and was constructed of rubber. It was operated from the ship above. The inky cloud effect was produced by pressing a bulb that forced the liquid lamp black preparation through openings in the body of the octopus. While the rub- ber arm was being placed around the diver's neck. the camera was stopped- Photo above shows Keaton rescuing his lady -fair by coming up from the sea. t L r J'cience and Invention for February, 1925 981 Pho.a.og--apilly SCHALLERT te NOT all pictures are taken under water, but the most spectacular motion d picture productions are taken on the actual settings as found in nature. ;` A place is usually selected where the foliage is plentiful, where sea sw..w.rr; . ferns and coral abound. Often the motion -picture camera is lowered into 1. . f : the chamber which is to receive it and ground for hours, until the fish :w become accustomed to the noise and do not start away when the cameraman commences his grind. In "Water Babies" the undersea views were taken eleven miles off the coast of Florida in still water around coral reefs. E ' . Masses of coral may be seen in the photographs. The , ;-- ,.t!h/ by _ apparatus, the r 9 . aid of which the scenes were was fastened photographed, to the bottom with 19' s:- long steel clamps and the cameramen had to dive down and make their .4 entrance through the open bottom of the tank before they could start work. ,,Í The air pressure was sufficiently high so that . the water would not rise more than half way to the top of the camera compartment, and v -t fresh was supplied by air air constantly r J pumps. The tropical warmth of the ocean in this locality permitted the operators to ' remain under water for several hours at a The boy stunt swim - mer could by the time, and the boy, a stunt swimmer, could RIP'. proper manipulation of stay under water for about eighty seconds.) i 91 weights act as though 'kb,: he were walking around on the ground. He is shown above The photo at the left going through a vent- r boy stunt shows the able f o r e s t of sea I. swimmer riding the weeds, and in the back of a tame turtle. photo at the left we was con- This turtle have further proof 1 trolled by two divers that the boy stunt who held thin steel swimmer is actually cables which were at- lit acting beneath the l tached to the turtle. surface of the water, When it was desired where the two divers to make the turtle sub- -- are assisting him merge, the cables were across rocky bottoms. pulled upon and the camera photographed the turtle swimming beneath the surface of t'z the water from the bottom of the Pacific. . _ . -FACE_ SOY GETS ON TAME TURTLE AND Is PULLED").- ` ' _ ..- _ ESW N TOWARD CAMERA BY DIVERS ' I THIN STEEL WIRES j I ATTACHED TO TURTLE /T In some would- II y be under -sea mo- tion pictures the scenes are photographed through a large glass tank. A girl dives into this tank to lend realism to the scene, while children playing around are photo- _t! graphed through a veil of water. The photo here shows Eve/ GLASS WATER TANK, the chamber which was _/` INTO WHICH GIRL DIVES L TO LEND REALISM used in "Water `.` taking áy3.1- r. Babies." The of y CAMERA PICKS UP front DIRECTOR this chamber is fitted ,,j. CHILDREN PLAYING CAMERA p IN SEAWEED with a glass window THROUGH ' I VEIL OF REAL WATER through which the - IN TANK scenes arc photograph- Ylsf 4-a1 ¿I ed. Air is pumped into the chamber. ! ...FAN TO CAUSE SEAWEED c. J TO BLOW,- IMITATING NOTION OF WATER CURRENTS ' I Ott . I CAMERA MAN DIVES I UNDER THE SHELL WATER LENS -USED, AS IN 'THE THIEF OF BAODAD"WHEN L- ', CLEARER PHOIOOWIPHY 7:1. t `a II IS T>._ + 1.- REQUIRED, --IN E E iñ4ta y -ti ---- (1."i COMBINATION WITHI SLOW MOTION FROM PHOTOGRAPHY FOR Itliv* f RE.SH AIR PUMP PROPER y A SUB -SEA , t-' I I TEMD'OOE MOVING 7F I . 1 f 1 r L CHARLES GOULD, NOV r . 1 i , STUNT SWIMMER, o I ¡. 11\ ` COULD SEAS' UNDER Instead of employing a large glass i EJGNT' SECONDS: ' tank into which a girl may dive and ; } t^'i RV M&NIPULATIND WEIGHFS -r HE COULD LIE DOWN AN, taking the photos through the tank, so PRETEND TO 1 , -il.. SLEEP that scenes placed in back of ít may t 1 C . i . likewise be registered on the film, a t much smaller tank Is sometimes used. 1 1 This is suspended immediately in front ,-,-,, ; of the photographic camera and may ,- t 1 have seeweed and fish In it. In t i combination with slow-motion photog- - - 'AIR PRESSURE raphy, it gives the proper tempo at .%`+F'i% t `k KEEPS wATER which bodies move beneath the sur- af,. ] =, _i1J`....: EROM 1M .:.---3-7;:. ,rmi E RISING N face of the sea. ,t ...', _ ..s/ úp REw,iy // -.../ .,c '''.:1 1r. 982 Science and Invention for February, 1925 So cual .Ilfe ©ír file An.1 By DR. ERNEST BADE Below-The worker of the red ant; Right-The brain consists of only 1/300 at times such individuals may at- part of the body; in man, the brain is 1143 tain the age of 15 years in captiv- part of the body. ity, which is surely a sufficient :::::11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111.111 lapse of time be learn to able to Below-The front leg of the ant is pro- and utilize facts observed. vided with an indentation and a brush to clean the feelers. The ant "clan" sees to the cleanliness of the individual as well as of the home. rr 1 --...-- . Y ir r A Small Republic THE male of the red ant, above to the right, is provided with wings. This form, as well as the ' án1: female, are the only forms provided with them. The rest, the "state," is sexless and wingless. Above 1 are the chambers of red ants eaten in wood. The workers are usually classed into groups. The smaller forms tend the young and keep the home in order. Similar individuals bring in food, others keep watch while still others are the protectors of the nest. The soldier of the ant is the protector. This cast is characterized by exceptional size and possess extraordinarily large mandibles. The burrows or paths of the red ant eaten out of the solid wood. In these nest building forms, each nest generally represents a state. But a nest may branch, and the branches formed may contain another community of the same form. Then these various branches are in friendly relation with the main nest, the entire network representing a "state." Example on right. Science and Invention for February, 1925 983 -r-e.--y- _=-r-.-- _- ----=.R, -1-T.. -. The general appearance of a common ant nest, together with "Irv_`f =. +^T the entrance hole shown in the insert is the type of home `+ y the ground burrowing types produce. It must be remem- .7-11k4-1/401., ¡3, e r7 bered that the ant cannot see more than a foot and the "odor 4 ' perception" fails at more than three feet. 4'11- F-'-..:_ . -: ti: , a yL , ' r r 0 Is,_ ó rºt : .? . . VOLCANO err ,'GALLERIES STORE ROOM FOR FOOD- . ---4-- LARVAE ROOM -- --MIN0W.n EGG ROOM The heads of the various casts of the red ant are shown center left. The first is the male with its long palpi. The second is the head of the femalS having a large brain. The third is the common worker, 'while the last is the soldier with its large massive mandibles. The interior of a hill showing the workers caring for their young in special cham- bers. Here the feelers play a prominent role, for with them they are able to communicate with each other, as well as feel and smell with them. ,1 11111111.1111111111111111/1111111111 lllll 111111 lllll 111111111111111111 ,11111111.111111 11.11 1111 I I 1 11 .11 , .113 The large carpenter ant, a big fellow, identified by the' peculiar knot situated between abdomen and thorax appears on the far left. .lll 111111111111/111111.111111111111111111 llll 1111111111111 lll I 11111111111111111 11 I . ., The queen of the red ants. In the nest each indi- vidual does its own work, at times helping or hindering its fellow workers. There is no team work, and if a worker is taken from its home, it soon becomes unable to care for itself. A striking example of the division of labor in the community. 984 Science and Invention for February, 1925 FIlnd FIlnd .(the By MEL WHAP.TOI4 - !" _ ;/ ` '7~ow (7.:41 - ( ;, - HAIR is the latest source of information to the E 111111111111 modern scientific detectives. The Berkeley and ir --r` ._ll Los Angeles Police Departments-the most scientific in the country-following the original investigations of Dr. Schneider, have investigated and annotated a large number of facts concerning the peculiarities of hair. From a little sliver of hair, half an inch long, the enterprising sleuths of the Los Angeles school can tell the nationality, the age, general condition of health, the comparative cleanliness or dirtiness, sex, color and weight of the individual from whom the hair originated. It is also possible to tell whether the hair is straight or curly, and whether the owner ,., is a victim to the use of pomades or curling iron, and whether the hair itself was torn from the head or fell out. The extreme value of such information to the police is of course obvious. In the sketches immediately below the magnification is about 500 diameters. Fig. 1. A tiny bit of human head hair showing an interrupted pith and numerous pigment granules. Fig. 2. Bit of armpit hair show- ing the abundant deposits of sebaceous mat- ter. Fig. 3. Bit of pubic hair showing two extruded epithelial cells. Fig. 4. Basal por- tion of human head hair pulled out by force as indicated by the transversely torn follicle. Sebaceous deposit just above the skin surface line. The upper end has been recently cut by sharp shears. Fig. 5. The shrunken follicle indicates that the hair fell out. Sebaceous deposit much reduced. Fig. 6. Transverse section of a straight head hair. Outline cir- cular with centric pitch. Fig. 7. Transverse section of a curly head hair. Outline elliptical with eccentric pith. Fig. 8. Bit of beard shaving, two days' growth, cut by means of a dull safety razor. Fig. 9. Bit of body hair of Cinnamon bear. Fig. 10. Bit of deer hair showing the very characteristic cellular pith. The cortex is reduced to a minimum, being scarcely noticeable. Fig. 11. Hair of Alaskan ermine. Fig. 12. Hair of Rhesus monkey. This hair shows the general characteristics of human The photograph at the top of the page shows body hair. Fig. 13. Body hair of dog. Com- the interior of the laboratory of the Los pare with hair of the coyote. Fig. 14. Bristle Angeles Police Department where the hair The various heads shown or hair of black caterpillar showing one prong observatiot_; and analyses are made. here illustrate clearly the or branch. Fig. 15. Bit of wool (sheep). difference between the hair There is no pith or medulla and there are no characteristics pigment granules. Fig. 16. Body hair of of different rabbit. Fig. 17. Body hair of Scotch mole. races and sub -races, which Fig. 18. Body hair of coyote. Resembles very is the first broad analysis closely the hair of the dog, somewhat coarser. made. iT 9 The analysis not only tells race, but it also demonstrates the particu- lar part of the body or head at which the hair originated, and whether the hair has been trimmed 12 recently or not. 'ate r9 N ra ^'': et= .ipy,ytW.t 41475. 14 1G 18 , (. . `+ L Detail of the drawings shown above are given at the bottom of the large caption. These comparative studies give a clear Idea of the origin of the knowl- edge used by the department. Science and Invention for February, 1925 985 SCIIerilee In 1Pficitures The News of the Month Briefly Reviewed IlThe versatile moving stage illustrated below has been designed by the -sculptor Kiesler and is in use is % Vienna. It can be moved up and down and revolved ' as desired. Right: Robert V. Jaros of the University of Chicago with a model "airplane constructed by him that stayed In the air for ten minutes, fourteen and two-tenths seconds. establishing a world's record. 1 ~ Il 1 .4 II . T{..-. Litman I - , 1' ii:, , st km t, . M ..-..a-`'1 Right: A novel aerial adver- tisement which for some time floated in the air 300 feet above Columbus Circle, New York City. It represents a well known make of balloon ...tire and in itself is 24 feet across. Made of very light balloon fabric, it contains 3000 cubic feet of hydrogen and ís held in place by means of flexible steel cables. From the street, the cables were hardly visible and the tire appears to be suspended in the air without any support If whatsoever. Needless to say, t1 ©R the advertisement created a wl 7 considerable amount of in- terest. -11~A' - f [ e 1 I Above: Ornamental lamp posts made by Ray Lambert, Park Commis- The above photograph by E. L. Braley is interesting in the sioner, San Antonio, Texas. Mr. Lambert uses discarded tin cans as extreme. It is seldom that one sees a photograph combining the core of 'the lamp posts, covering these forms with concrete. Thus, such a wonderful reflection with that atmospheric phenomenon ugly refuse is turned into a useful channel. known as "the sun drawing water." 986 Science and Invention for February, I92' e LIIVIING J' E AT11 By JOHN MARTIN 1L,EAHY , ( ,, i f f et Frontenac stood at the entrance to the f eer- ing-room and. as a dog i á was brought forward, 'L/Lt he made an injection an the animal's neck. _ /1 The two resumed their seats. SYNOPSIS "I found her," said the captain, "but Captain Lut+nystone, au Antarctic explorer, Paradise, as this spot had been named al first, ant a doomed man; I shall never see her cans into conference a famous scientist, Darwin the two o,cn travelled onward. Some distance again." Frontenac, who has distinguished himself in re- further on they discovered a cave, the floor of search work involving methods of inducing which was covered with a thick coating of ice A strange look came over his visage. His hibernation in mammals. In the presence of and encased in that ice they found the body of lineaments moved in a wan, melancholy Mr. dicQuestion, a reporter, Captain Living- a beautiful young woman, clothed as out): in- smile. stone rceo,rnts a weird tale of exploration and habitants of a tropical country would be. The discoveries in the Antarctic. He tells how, with Captain formed the opinion that this girl was "I am getting up in years, and, if the a well equipped ship and a hearty crew, he not dead, but was in a stale of suspended anima- truth must be told, I am, after all, some- started for the South Pole and hots', far south tion-in other words, neither living nor dead. of the Antarctic circle, land was discovered. thing of a hardened old sinner, and yet-" Leaving part o the crew at this point and trav- It was with this girl in his mind that the That smile slowly left his face, and for elling overlap , the explorers found the air to Captain approached Darwin Frontenac. His become wanner and to their great astonishment object was to induce the scientist to exercise a time he was silent-a strange, rugged they discovered is land, surrounded by high moun- his knowledge toward bringing this beautiful pitiable figure. region young girl back to life. After the facts stated tains, the temperature of the being far I above the freezing point and where paten trees above had been recounted to Frontenac and'Ii,. "And yet, gentlemen, sometimes think and luxurious flowers flourished. During part McQuestion, they agreed to go to the An/brcfic that-yes, I sometimes think that I love of their-exploration trip, a "Thing" unknown to regions and attempt to revive the girl if, to that girl." them killed all of the explorers with the ex- quote Frontenac . -that 'Thing' in the ception of Captain Livingstone and a man by Garden of Paradise doesn't get us within the Darwin Frontenac's look was suddenly the name of Hampden. Leaving this Garden of reach of its claws." keen and questioning, then as suddenly was what it had been a moment before. FIFTH INSTALLMENT CHAPTER XV ANOTHER MONSTER-THE DOOR CAPTAIN STANLEY LIVING - STONE came to his feet and reached Y. out his hand ; Frontenac too arose and extended his own; and the cap- tain pumphandled away at him in fine fash- ion. "I knew, Mr. Frontenac, that you would do it r' he exclaimed, the puffed and livid features working with strong emotion. "I o knew that you' would awake my Sleeping Beauty I" As for myself, my astonishment was very great. This was not like Darwin Fron- tenac. I had thought that he would give this matter-one of the strangest and wild- est things, certainly, that had ever been presented to any man-long and careful at- tention. And now look! Frontenac had already answered-answered before the ex- plorer had even finished his story! . "And you, Mr. McQuestion?" the captain said. "Are you going to go. too?" "Really the thing is so unexpected, so strange. I must have time to think it over- that is, if Darwin wants an Icicle Mucky - muck like me along." "You know nothing would please me more, old tillicurt l" "Well, I must think it over." The figure, cut out of the living rock, was a colossal one, being thirty feet In height and fully "Of course," the captain nodded. "Of fifty in width. It was perched upon a heap of (sculptured) human skulls, the wings were course." outspread as though it was about to launch itself down upon us Science and Invention for February, 1925 987 "Yes, it is so," said the captain, burying and Nunatak on his way down from the his face in his hands. "I could never forget North with the clogs-genuine Eskimo dogs, her. Call me an old fool-call me what from the Tinnanannomook country-and you will! She was so sweet, so lovely there now, like a bolt from out the blue, came in her bed of crystal-a sight so sad that this sentence of death! I wept to see her lying there. But I shall "What was to be done? Should the Mult- never see her again. My aneurism may nomah sail anyway-the expedition to go burst at. any moment." on under the second in command when .the Darwin Frontenac glanced in my direc- aneurism finished me? I didn't know what tion. I saw in his eyes only wonder and awe. to do. And, while I was trying to decide. The captain raised his . head front his I read of your discovery, Mr. Frontenac, hands. That wan, sad smile-a thing I could and I made up my mind to come to you never describe-passed over his features and tell you what 1 had never told any once more. man-the whole of my story. Thank God, "An old fool's weakness, gentlemen," he I did come! I shudder to think, though. said, giving a melancholy wave of his hand. how near I was to backing out, for I was "1 don't know why I have told you this. afraid you might regard it all as nothing Heaven knows, I never intended to tell it but a fairy tale. to any man. But what, after all, does it "I suppose, however, that the Multnomah matter? 1 shall never see her' again. But es will be ready to cast off by the time that you will see her, Mr. Frontenac, and you, MOLT NOMA ti you can net your affairs in shape. When too, I fancy, Mr. McQuestion. Yes you I decided to come to you and tell you my will see her there in her tomb of ice-per- story, the first thing I did (on the chance haps on a day see her smiles and hear her that you might believe me) was to draw laughter. Perhaps you-both of you-will up papers that would forestall any hitch or love -her too. difficulty in case I should be bumped off "Poor -little kid as Hampden said. You before the expedition got away. There is will be good to her, Mr. Frontenac, I know. no telling; I may live for months, and, Yes, she will never regret that you awoke again, I may go at any moment. However, her, or you regret it, either. In a way, she I have fixed matters so that, if 1 die this will be your daughter, unless, that is-a minute, things can go on as smoothly as thing which I think not unlikely-she be- r though nothing had happened. comes one even dearer still." "Your discovery, Mr. Frontenac, will It was Frontenac now who smiled. He A few moments, and we had cleared the pier make at least one change necessary: you will, made no response, however. and were out in the stream. I suppose, want a freezer on the Multno- "But," said the captain, "who can say mah?"" what will be? All that is in the future. tak in Alaska, Mr. McQuestion? His real "By all means." "As for the expedition, today would have name is an odd one truly-Louis Louisiana." "I didn't think that you would awake her found us almost ready to put to sea-per- "Oh, yes." down there." haps, indeed, actually under way-if it "A fine man," said the captain. "They "Of course not." hadn't been for this hellish aneurism of say that he is one of the best, perhaps the "That's what I thought. So there will mine. I had known for some time that very best musher in all the Northland. He have to he a freezing -room to bring her there was something wrong. I thought, is as tall as a bean -pole, skinny as a poker, back in." though, 'twas nothing serious and that it and one eye is black and the other is blue. "Just so. And there are the dogs," Fron- would pass away, as so many other things Ever meet him up there?" tenac reminded him. "How many?" had done. But it did not pass away. It "No. I've seen many a man up North "About one hundred." got worse instead of better. And so finally with one eye or both eyes black and blue, "The freezer must be large enough to I went to a doctor. I demanded the truth; but I never saw a man, there or -any other hold all those dogs, with some additional he gave it to me. I went to another and place, with one eye blue and the other black. space. For we will kill them, pile them up in yet another ; it was the same thing. It was I remember hearing of this Nunatak, the freezer and thaw them out when we quite a shock at first, gentlemen. For a though." reach Summer Haven. That will be much time I tell you I felt mighty bad. But I I turned to Frontenac. better than having them crowded about the brought my philosophy, such as it is, to bear "Ever hear of a map with peepers like decks, to say nothing of the saving in food." upon the matter, and I soon resigned myself those before?" "By Joe!" the other exclaimed. "I never to my fate. "Oh, yes. Never saw such an one, once thought of that." "But what to do about the expedition? though." "However," Frontenac said, "these details Things were rapidly nearing completion. "As I was going to say," the explorer can he taken un later. I am anxious, Cap - Nunatak-maybe you have heard of Nuna- went on, "there was everything almost ready (Continued on page 1048) i. ' _2 L There was a cry, and I looked up and saw Hampden make a wild 'effort to turn and save himself, the rear end of the sled tip up, and the sled slip forward and vanish, dragging the dogs down after it. 988 Science and Invention for February, 1925 "Death Ray" in MovIles . r They Do It In the Movies!! . -..1ti Left: A n i 5311 cam ac ti on scene from the "death =-+ ray" movie. , 1 The inventor of the "death ray" recently staged a movie on that subject for Pathl. 1 In the movies, "death ray " performed a s below. LIÁMP D a Y, íC11924 BY SCIENCE ( & INVENTION I' s GU Above: One of the elaborate property settings V used in the filming of the G indell Matthews' STOPPED--sue "death ray" movie. MOTORCYCLE KILLED RAT HarÍlinfless X- wet sr . ow* BRILUANT RED GLOW f CHEST, UNDER CHEST UNDER fORDINARY X RAY COLD LIGHT l! _ tGJ t - ' _ . Lowy? HEMISPHERE ./1:k 7(7'1V. OF EACH LAMP IS :` LVRRED RLFLECTOtt . "*"`_44. I 1-irj1 The medical world has recently been startled by a statement to the effect that in France there is in use a device which gives the .effect of an X-ray, yet employs none of those emanations that have bees known by that title since their discovery by Roentgen. The device which gives this effect is illustrated at the left. It Consists of a series of 30,000 -watt lamps, half silvered, as shown, mounted on a totatinj wheel and lighted at the instant that they pass a .given point. At this point, the rays of the lamp are directed through a lens so that they give the effect shown. Each bulb is used for such a short space of time that, it is claimed, little, if any, heat reaches the patient. The light is, therefore, called cold and in the upper lefthand corner of our illustration is shown a comparison between a photo taken with ordinary X-rays and "cold light." The blood vessels and organs can be seen. 101924'BYdC1ENCE AND INVfNTl(SN Science and Invention for February, 1925 989 ®Ilson Gas She lls By LIEUT. ROBERT E.SADTLER, Chemical Warfare School, U. S. Army ENEMY TRENCHES.' ' `.6.ri+. -T - +T¡L h:1 *ir t,-r LD METHOD OF MOUNTING 't - PROJECTOR GROUND The various gases and solids as well as incendiary materials have been studied and experimented with by the United P L States and other world powers to such a / aicare_ . ti an extent that they are very effective. r These gases and solids have been incorpo- .be f ! rated in shells so that they can made deadly, even at long distances from the trenches of the users. The illustration é t directly above shows one method of mounting the projectors of these shells known as the 8 -inch Livens type, after INCENDIARY the inventor. They are mounted so that SHELL CAU 45 LIQUEFl GAS PE the mcuth projects at an angle of PARTICLES CHANGE FIRE A degrees. TO GAS BY ºNPORATtott UNQO 0 The three most important gaseous chemical An entire battery of Livens projectors are agents used in chemical warfare are mus- wired together in series as shown at the tard, phosgene, and chlorpicrin gases. left and are simultaneously detonated from Also there' are three important solid ma- a single point by means of a magnetic device. terials used. They are diphenylchlorarsine Tne insert above and to the left' shows the shells.. used as a toxic smoke, diphenylaminechlor- effect of bursting gas and Incendiary the same purpose and chlora- arsine for METHOD OF WIRING PROJECTORS MAGNETIC cetaphenone which evolves tear gas. DETONATOR _4-T Y -..r SHELF 0' LswrpN ITALIAN MASK GERMAN MASA' f/RSTaLACYVE/L-i OPEN CLOSED 4Q0 TYPICAL ARRANGEMENT FOR GAS -PROOFING DUGOUTS SNOWiAGJM/RTOf ` \ flR/T/SN BR/ 773N MASK MICRkAN TISSO7 NYRqP.. PLNELALrT S.WII aaeRESPRA7LN FRENCH TISS07 RUSSIAN -/SHELFDETAIL SHEAR WIRE The illustration in the lower righthand cot BROKEN BY ner shows an improved American method of CONCUSSIO mounting Livens projectors that is equally as LIQUEFIED GAS effective as the old type, and can be placed In INERTIA one -fifth the usual time. PROJECTOR C OR INCENDIARY PLUG 41. FILL! - STAKES PRIMING Above and to the right are illustrations of CAP LIGHTS various types of gas masks used in the World ETHER FUSE War. Note the variations in size attd form. 12 SEC. FUSE At the left is shown one of the improved types of Livens gas shells as used in the projectors DETONATOR illustrated herewith. Note the simple, yet \MR FIRES . effective method of breaking the shell. Di- PIVOTS DRIVEN rectly above the shell is shown a typical ar- /INTO GROUND rangement for gas -proofing dugouts. A blan- BURSTING ket with laths nailed to it at interva's serves CHARGE as an effective block to the gas when the edges are weighted down. -AN AMERICAN METHOD OF EMPLACEMENT CROSS-SECTION OF PROJECTILE 990 Science and Invention for February, 1925 octor ;. i ackensaw9s Secrets By CLEMENT 'FEZANDX1 No. 36. The Mystery of the Z -Ray r Spectacles. raveling a most "Good difficult case. But first let gracious!" cried me ask you Miggs, "t can see right something. I am informed that through the wall into the Dector ' Hackensaw has invented a wonder- office where the clerks arel" ful pair of spectacles-X-ray spectacles, I "Yes," assented Doctor believe they are called-by means of which Hackensaw dryly, "I some- the wearer can see right through people, or 4kM times look at them myself, even see through the walls of a and must house what I say I don't often is going on inside. Is ace you that true?" working, Miggs- "Yes, ma'am, perhaps it's on account of only he calls them Z -ray some trouble with the spec- spectacles, because it is not the X-ray that tacles." he uses." "Have you ever worn the spectacles? Do you know how they work?" "No, ma'am, but I heard the doctor say that they were so simple that anyone could use them." "Do you think the doctor would lend you a pair for a few weeks. I don't want him to know that they are for me. You must ... ask them for yourself." "I think I could get a pair," replied Miggs, non-commitally. "Very IN Doctor Hackensaw's employ there was To say that Miggs was surprised to find well. Now here's what I should a like you bright boy of fifteen named Tinta - that he was really the person wanted, and to do, and remember, there is a geles handsome Smith. The name is pronounced that the young lady even knew his name, reward offered; in fact, I will give you Tin-taj-jill-leeze, but as most people would be to put the matter mildly. He was one thousand dollars in case of would not take the trouble to pronounce it "flabbergasted," but he managed to answer: success." Miggs' correctly, they called him "Miggs" for short. "Yes, that's my name, but my friends all eyes gleamed. "All 'right," said One night Tintageles had an adventure. cull me 'Miggs.'" he, "I'll succeed! What is it you want me to do?" Doctor Hackensaw had given him a ticket "Very well,. Miggs," returned the young The for the theatre, and at the end of the per- lady, smiling. "I understand that you work lady glanced at her watch. "It's a forma4ce the boy had started off to walk in Doctor Hackensaw's laboratory?" home, when a. high-class automobile drew "Yes, ma'am." up to the sidewalk alongside of him, and a "And I am told that you have the mak- beautiful young lady in evening dress,and ings of a fine detective in you?" glittering with diamonds, leaned forth from Tintageles blushed. This was taking him the car and beckoned to him. . on his weakest side. From boyhood up he "Jump she in," said; "I want to speak to had hesitated as to whether he would be you." President of the United States or a detec- Tintageles turned around to see whom she tive, but finally the fascinations of a detec- was addressing, but there was no one else near. "It's you I want," insisted the lady ; "jump in 1" Our young hero was convinced that the u lady was mistaking him for someone else, but he was always ready for an adventure, so he jumped in and took his seat beside his fair interlocutor. "My name," said the lady, "is Miss Muriel Gold. You may possibly have read about me in the Society Notes of the papers. Your name, if I am not mistaken, is Tintageles Smith." # g1' long story," she said, "and I haven't time to go into particulars tonight. But come to this spot tomorrow night at ten o'clock and bring the spectacles with you. I shall be here with the auto, and bring you home with me, and then I'll give you cull details. Au revoir till then!" CHAPTER 11 "No, Miggs," said Doctor .Hackensaw, "I can't lend you a pair of my. magic spectacles: haven't made the invention public yet, be- cause' I don't dare to let these spectacles go out of my possession. am tive's I afraid they life carried the day. The lady's words might be used 'for mischievous purposes. But accordingly touched him in a tender spot. I have no objection to letting you look "I have so much faith in your abilities through them. Here is a pair. The spec- as a detective," continued the lady. "that I tacles, of course, fit over your eyes. As you have decided to make use of you in un - see, the wires that connect with the ear- 99I Science and Invention tor February, 1925 pieces that support the spectacles, pass down "My starting point was the discovery made "In my experiments , under the back of your coat and then by Frederick Lane in 1912, that X-rays could I chanced to discover a new ray, which I through a hole in the pocket to the radium he reflected by special crystalline surfaces. battery and audions which are contained in In a mixed fascicle of X-rays of different called the Z -ray, and like a small case that fits in your pocket. The wave -lengths, he found that the surface which, ordi- adjusting screws are on the outside of this would reflect those rays whose wave -lengths nary light rays. case. The large knob controls the distance correspond with its own molecular structure. and like the X-ray to which the ray goes before it is reflected. So far, however, this discovery has only and the beta ray, Here, put the spectacles on your eyes, and been used in an attempt to determine the real the case in your pocket. Now take off your arrangement of atoms in space. coat while I make the connections. All "Finding myself unable to make any head- ready. Put on your coat again. Connect way with the X-rays, I turned my attention the spectacles with the wire and look at the to some of the other wall.'. rays. To begin with, Good gracious!" cried Miggs. "I can Miggs, I must tell you see right through the wall into the office that there are a large where the clerks are!" number of different "Yes," assented Doctor Hackensaw, dryly. kinds of rays. Radium, "I sometimes look at them myself, and I for instance, throws must say I don't often see you working, off three kinds of Miggs. Perhaps it's on account of some rays, known as the trouble with the spectacles. Now, if you (alpha), (beta) and want to see what you look like, just turn the adjusting screw to the left, and look at yourself. You can.get a pretty good view of your ribs, your heart, lungs, has a wide variation in wave -length. stomach and other organs. These "My problem was to separate this ray into spectacles are invaluable to a physi- - : a number of homogeneous rays of a uniform cian in diagnosing the condition of wave -length. To accomplish this I used each organ of his patient. In crystalline surfaces like those used by Lane. fact, there are a thousand uses I found that the rays with different wave- to which they may be put." lengths penetrated to different depths into the "What is the principle on bady viewed before the light was reflected. which they work?" asked Tin- By using one length of wave I would get tageles. a reflection of a flat surface inside of the "Their construction cost me body-a sectional view. An adjusting screw many a sleepless night," replied enabled me to view a section at any desired the doctor. "Yet the probleni depth in the body. A flexible diaphragm seemed simple, since I had the that can be made to assume any curvature With t h e Z -ray at will, enables me to view a curved surface, spectacles our po- such for example, as the outer surface of licemen would be heart instead of a plane section through able to detect the weapons, bottles of the heart. With a very little practice any- Scotch, smuggled one can adjust this. diaphragm and the dis- jewels, et cetera, tance micrometer screw so as to see any hidden about the portion of a man's organs that he wishes to person or in auto- examine. I have also a special attachment mobiles, as t h e which enables me to read the letters in a central illustration again, shows, Imagine man's pocket. Put on the spectacles how our bootleg- Miggs, and see if you can read the address gers would scurry on the letter I have in'my coat pocket." to cover if they Miggs adjusted the spectacles once more police- knew our and then gave a cry of astonishment. . men . were armed "Gee!" he exclaimed. "Why, I can look with these pene- insides. I can see your skele- trating spectacles. right into your ton and your heart and stomach and every- And all in natural colors-not in ray, respectively. The X-ray, thing! y (gamma) black and white like an X-ray picture. And is analogous to the alpha ray, travels which I can see all you've got in your pockets, too. only eight thousand to sixteen thousand kilo- vary from I can see the bills and coins in your pocket- meters per second. The beta rays read what's on your rail- light rays to approximate- book, and I can half the speed of road ticket. Say, doctor, can't you lend me ly speed light rays,' some particles the of a pair of these spectacles only for one traveling slowly and some fast, for both the and week!" alpha and beta rays are corpuscular "No, indeed," replied the doctor. "Think a The ' can be deviated by means of magnet. arise if a bad use were -^ not seem to be in- what harm might gamma rays, however, do made of them. They would be invaluable I ~i. fluenced by magnets. (Continued on page 1026) v To open a window and climb into the house was the work of an instant- Pep, Joe and the three men put penetrating X-ray to start with. But the on their gas -masks, and then placing the nozzle of the progress of invention is always very slow. gas -throwing instrument into the key -hole of the room Man must have been familiar with his own where the villains were assembled, shot the odorless shadow long before he noticed his reflec- but powerful soporific gas into the room. A minute was later every member of the gang was unconscious, and tion in a pool of water. And water before they recovered their senses they were strongly his only mirror until a few hundred years handcuffed. ago he succeeded in making metal mirrors and then glass mirrors. The use of lenses to refract light came long after the use of mirrors. Finally came the X-ray, which is ! still in its primitive stage-the stage in , which it can merely throw a shadow. At- (11 tempts to reflect and refract these rays were tT only partially successful. "Then I took the matter in hand. The :* analogy of the X-ray to the heat and light . . Olt rays is so great that I knew there must be /1 r_ some way of utilizing them for the spec- ti- > ,27." , tacles I dreamed of-spectacles that would J" //1):.. enable us to look either throualt or into solid bodies at will. \\\14' 992 Science and Invention for February, 1925 Everydy e em3slry By RAYMOND B. WAILES WHY DO SO MANY THE RED SIGNAL MEDICINES CONTAIN 15 THE RING LIGHT AND ALCOHOL? AROUND THE RADIO MOVIES TUB DIRT? ARE CLOSELY RELATED 3 Selenium tints gl es red and is To dissolve some of the ingredients not also the heart of television . soluble in water, not as a stimulant. aooara us. No, not entirely. It is mainly a substagje formed by soap and minerals. THE RED LIQUID IN GUN COTTON IS NOW THERMOMETERS USED IN PRODUCING ADD A POISON,,;,, r IS NIT RED THE FINISH FOR THE TO YOUR SALTS ERCPRY, IS IT? SNAPPY SPORT 'CARS I% IODINE SALT .,;, ai PREVENTS THIS - 5 The glossy finish on high class sport cars 'GOITRE is usually due to a paint containing non- explosive gun cotton. Iodine in the proportion of .01% in salt Metallic mercury is never any color but prevents goitre and is harmless. Some silvery. The red liquid is IS IT TRUE THAT manufacturers cohol contain- call this "Iodized Salt." ing a red dye THE HARDENING OF COPPER HAS BEEN WHAT MAKES SOME RE -DISCOVERED? SOAPS FLOAT? 'COPPER KNIFE Hardened copper is considered by metal- lurgists to be nothing but copper alloys. Because of the fact Aluminum bronze would be a more appro- that there are min- priate name. ute air bubbles in The gold color is imparted by powdered brass the soap, not be- or bronze. This can be pro en by a flame IS CARBON MONOXIDE cause of any secret test, which will show green. ingredient. RESPONSIBLE FOR pry GAS ASPHYX- i'IATIONS? HOW ARE THE IRIDESCENT COLORS S`4 PRODUCED. ON HOW CAN YOU GLASSWARE? DILUTE BLOOD TELL IF"MONOXIDE' IN TES COMES FRom -- TUBE 11 YOUR ENGINE 10 EXHAUST? `12 Only partly. Ethylene or "looney gas" plays Diluted blood will turn pink when exposed b a part. This gas gives illuminating gas its By allowing the vapors of metal chlorides to exhaust gas, if carbon monoxide is present. yellow color effect. play about the glass while it is heated. Science and Invention for February, 1925 993 Gliands Assist Ev®hatI®n ' CALLOUS / - HEREDITARY ¡L{ . /1'.'-" - : %,,% MESEMT-MY 1 ((,i "4.'440 r r +J1/ //PT ¡/- 7+ y l ANTLERS 1 J CAIIOUS.'% Ir, ' .' .y\, .! N. / i > .1y ,v I 'd . r , , ' . ! r-J^' t>21,'e- ' / i:9 , ` ./ ' t _+i +^.- ..tll111' ``í. /A f A L Y //'\\ ,lySyri-\ riG'!%n! 1_ 1¡ _ \ -A¡+ 1J1,/? ,.. it,1'; ' "Wls.á.I /L' _ II sr / - ; -='` iG 'P''i°-- 7l91i/f .. '4 /// I 'Y r . -, r -/. \ /. Ivey// y . -i /. ' ./I :.'.% , , \\ \ .,' - , s`,-. L ' z i.:,.i ,- , t ' j i. --z.... A`a, ,, \ i`114,,,'% .i ' `"_A - `1 R ' tl= 1^s : /l t'T 1 1 E ' , ` ? ,'ltr . i CV' _' i \\ .-/ '.9'''' ,r~ ' ` , . -r ; -_ 1 _, l,- ¡¡l/Yj E"...a.._HEREDITARYCALLOUS0R5W3 T \ MALE IEMALL MAIE WIIHWITMOUT / /¡-- 1 $MAIItST OlwY4t Y` ' ,./ RUMAGE AT \ ,\`\ ` I /' }Í T , \ 1 n.. F 1r..5 lia. - . 7t' \My .-. \\ 1. q ' - - .,., t mama.. -' r %/ - T' 91 y 1 ,.I ., ' IfTY I A i tlI OMR % .,// I. Y / t ,14. ., í-T -..,...,,....14,_,. i ,- //"gr .-a i ii\ w" íj 'I / / i ,,ay1=.Il- , r:Mi . ._V r> -- \ ,1 . If !. : w. MALE WITH __ `O' .,-1,-...-- HLREDITARV "`111 - , ¡yl !1 y--__ `/ . ..¡¡E1,_,.. .,.,11 ..._."2:..,__ .- l\ l L. _-- _.SL_/'- LUAAOE /,: :_ . S.YLMAIE J _/-AioIUMALE V:\\,\1R \, - - bruises at the skull That the endocrinal system/ which governs the- growth of mammalian bodies cock's plumage. In the case of the cock and deer, the will automatically adjust itself and the body to any set of circumstances and feet cause certain impurities to be fed back into the blood, which cause over a number of generations, is clearly illustrated according to Dr. T. J. the glands to construct a natural projection. In the case of the plumage of Cunningham in the case of the deer's antlers, the cock's spurs and the pea- the peacock, it is a matter of natural selection. Salfe.ey Razor- BIlndle GIlves 400 Shave5 BLADE IS ALWAYS SOFTEN STROP BY BEFORE THE LAST TISSUE PAPER PLACED STROPPED BEFORE APPLYING SMALL STROPPING BLADE ACROSS EDGE OF BLADE! AND AFTER AMOUNT OF VASELINE 15 WIPED AS DRY AND SNAPPED BACK USING TO FINISH SIDE ONLY. AS POSSIBLE IN POSITION. DO NOT FINAL STROPPING tl DISTURB UNTIL USED A' ii, I r LEAVES FILM OF v .- AGAIN cl GREASE t t- L _E. - 6. 5 r,' ¡'+ _ -- / _ a f 1 A year's shaves from one safety razor blade may be obtained if the blade is piece of tissue paper while not in u e. The sketches above show clearly the stropped both before and after shaving, and the blade kept covered with a necessary steps in the technique.-O. H. Knoon. 521ro-, n e§2 Lock. Radlo BaTleiry FOIL' Dranfing Pa Jw.,l.nrpn n b.h vV .d; I.r ll M.e.tti., - . 0 /r-rM1..- NVI ZINC NEGATIVE COPPER OXIDE Tr The strength of laminated construction is POSITIVE used to advantage in this latest design of STEEL JAR HOLDING padlock shown above. The body is con- ALKALINE ELECTROLYTE structed of laminated cold rolled steel sec- The most recent adaption of the Edison prim tions and will withstand much more pres- The ary cell is for radio work illustrated above, instrument shown above, a combination sure before releasing than the ordinary type tee square and be found Each cell gives approximately .7 volt. protractor, will ex- of padlock. Only one key works it. ceptionally useful to the draftsman. 994 Science and Invention for February, 1925 Remawnable ew By JOSEPH H. KRAUS PYROPHORIC ' SUBSTANCE SPRING rti : ,. a =I CELLU- LOID .,) JAI EYE EMERY 000f, WHEEL \/ SPRING FOR.RE- WINDING The toy illustrated above is a repro- ~Pe duction of the famous comic strip fig- ure "Boob McNutt." STRING It is a small , spring operated toy about 8 inches high, which dances on its feet. The , ' internal structure of the apparatus is illustrated. Notice that a bent lever ; Í, oscillates the legs. h a i ,,BALL (' e _ , .1 ._- The face with the sparkling eyes is illustrated herewith. Like the other toys on this page, it is made of metal and beautifully colored. The eyes are of celluloid. The Air 0 . toy is operated by pulling the string, which rapidly _ % Q. _., _--a revolves a pair of small metal wheels covered with emery. A small piece of , pyrophoric metal bears on the =....rrs:-w . emery wheel and pro- . `J duces a shower of sparks. '. - The string is wound up 5 . automatically. FIGURE '+ KEY PLACED HERE I, I ,.r JrSPRINGS ro ..,t .. I 0. , ".;- SAFETY ,e..,S P. 't f I - --VALVE l'' flq '4'/.,, CON- -, ¡'.1/1 , DOORS TROL ( .í~;1, :r't CAN-: -M o -- OPEN , , 4! . PISTON ''''» it H ryI STAND , , -'FOR BALL 'I tZ3 L The toy above is a baseball play- er who realistically swings at a small wooden pellet and sends it The photo above shows a .W Y toy steam -operated auto- out to quite a distance. The IC stand contains a number of balls mobile with the radiator STEatFfvd } and an automatically controlled removed and the engine ball -GEAR, hood lifted to show the raiser carries the balls up- 11 DIFFERENTIAL f3p TIE boiler. The has wardly o .: automobile in position to be struck FUEL .ril_`e by the player. As may be seen ; ROD ' a spare wheel and tire and ft TANK 't - rIV t is equipped with a from the drawing of the mechan- lye clutch. 0l` 1 ism, the toy is well constructed It travels across the floor considering its retail price. The CLUTCN! E,NGINE! lively speed y its .rr. ; . own motive power. bAleo- mechanism is simple and does not hol is used as fuel. soon get out of order. a, -?- - ÍRUMIÉR TIRES : . Science and Invention for February, 1925 995 M echanIl c a: Tayg HE toys illustrated on this page are all well constructed and the majority of them very reasonab.y priced. We will be glad to send names of manufacturing concerns mak- ing the toys here illustrated as well as several other toys which we have tested but because of lack of space found it impossible to illustrate, to any who are interested. Simply send postal requesting this. service. " . The toy at the right is a mysterious power boat. It is operated by a small piece of solidified alco- hol which is held in the base of the stand to which the figure is attached. This heats a small boiler -like compartment having thin metal diaphragm oil top. Steam being produced in this boiler is driven out through a pipe beneath the water and its reaction upon the water pro- pels the boat forward. Immediately cold water rushes in to take the place of the expelled steam. The boat then put -puts forward mer- rily and will continue to do so for hours with- out renewing the fuel supply. The sound it ) emits reminds one of a power boat. ' - The balking mule illustrated below is a very clever novelty simply constructed. The wheels of the toy are securely fastened to the axle, which is equipped with two gears. These gears mesh with a semi -circular gear which in turn is' _ - - 1 __ driven by a spring. The semi -circular gear causes the wheels of the cart to rotate first in n one direction and then, rapidly reverse and rotate in the opposite direction. The figure - jumps up and down and the mule rocks back and forth. The device never repeats the same v . movement twice in succession. At times the mule will be lifted into the car and the cart will whirl around while in this position. FIGURE SITS HERE t -¡']]Ol t: ' .guts. '.' e'. ; `u.r.. ,if ,K \ 4 .y SPRING S ' .;:".."1111 ., AXLE a. KEY -,-41,t.-1.-;',4 -C,-, , The toy illustrated herewith is made i, of wood and metal and differs in this respect from the other toysllist- -i - Íí,/ ss, . \\ ed on these two pages which are made I/: almost entirely of metal. At one t` \i'1, end of a double trapeze a circus : - , ar" clown is found to be hanging. About " \` _._' b,%.,,f`: two feet from the trapeze a spring / . Z,-----1 made of a piece of steel spring A L i,. 1 board `:^ I . . and a wooden seat is found. A sec- ., ond wooden figure is then mounted : on the seat. The seat of the spring board is pushed down until it engages in a small wire catch. When the catch is pressed down with the thumb, the seat is released and the figure is hurled upward into the air. Here it describes a complete turn and hooks itself on the top bar of the trap- eze. The momentum imparted is trans- J ferred to the trapeze and both figures whirl around and around quite a few times before coming to a final rest. A thumb screw adjusts the tension of the 41, spring board. (C)1924 BY SCIENCE & I N1fENTl O N 996 Science and Invention for February, 1925 5.(totreoscopIlc MovIleg N... .".----. -./ t w.,. HARD EDGE AT TOP BROKEN UD BY DRAPERIES, PLAN ADAPTED TO THEATRE WHERE . e HUNG SEVERAL FEET IN FRONT OF SCREEN, .iIII IMAGES ARE PROJECTED FROM BEHIND THUS:-, SCREEN `.11/4 AUDIENCE '' SCREEN BLACK VELVET DRAPERIES ARE ALSO HUNG .~1pH, CURTAINS-T `T V1b.{ai,+ír.á s4...i. *4., ,.} e DOWN EACH SIDE TO HELP T'!1 f.Xii BREAK THE UNNATURAL ,-.-1;:.,,y.,.14.(...,97. STRAIGHT LINE M Imo, THE VIGNETTE OF SIDES 15 GAUZE DRAPERIES + 'a'sy..,=^- II1 :" FURTHER ACCOMPLISHED BY r1j HUNG IN FRONT ,. - BEVELING THE END OF WIII -% I OF TOP AND SIDES !e SCREEN OUTWARD TOWARD IREf ORNAMENTAL SHRUBS AND THE S N4 Fj ! TO BREAK BOTTOM LINE AUDIENCE TINTING IRREGULARLY so THAT BEVEL I' ,t. ,p IT MERGES INTO THE BLACK IIII ,oI'I , L'1i'I/// ' STAGE 41t4 SIDE' CURTAINS; THUS...... a 9', .FIt''lír ,,,11/411///i //i /o/i/;/ :- / GAUZE DRAPERIES/. . % Giving moving pictures the illusion of solidity has been the dream of HELPING TO BRtAK /// r%L LOWER EDGE OF SCREEN BROKEN .TOP AND SIOE / up WITH HRUBS many an inventor, but unfortunately most of the pictures of this nature ''/ EDGES ./,'iii%/i//üuy projected the screen entailed the necessity of additional AUDIENCE heretofore Upon expenditures for re -design in projection apparatus and further expendi- ii/ / In system SHADOW BOY , :OP/NQUE GLASS. tures for some kind of viewing screen. the here illustrated, DINSIDEARKENED ON ' IRREWEAR IN the same effect is psychologically produced by O. A. Owen. By taking r CONTOUR AND away any vestige of a straight edge and draping sides top and bottom GROUND GLASS.% VARIED IN DENSITY of the screen with irregular drapings, the result is more than surprising. SCREEN y. / //4 ©19P4 BY /l/1 Scitricr wifiarw ioN --PROJECTOR Some Unlollvod RIlcQI dile5 off' SeIlenco s y CLOUDS WEST -ailI1 J EAST NARROW SOURCES VALLEY GOLD\ NO GOLD CLOUDS ,HERE HERE OVERBURDENED . - CLOUDS 11:44 DIAGRAM OF A 1hI' L f RIVER SYSTEM WEST- 7' 'h I° I - - - -- _ ` S OFl+F= í 9é ql TÉ - 'GOLD WILL BE FOUND 1 X MOUNTAIN'ss.F llli í IN THE FORKS MARKED'XR -- OCEAN_ 1 When gold is found near the head waters of a river system, it is almost England, America and Australia. Why? Water spouts are formed by invariably found in the right hand branch, if the observer stands at the centrifugal force. When a water spout occurs on the ocean, salt water is source and looks down stream. Gold miners know that the spots where the carried upward. Why is there a deluge of fresh water at the moment the sun shines before noon are always richest in this precious metal. This has spout breaks? -O. Ivan Lee, B.Sc., F.M.S.A. been found true and verified in such a widely separated countries, as The AT4Ilíf°ncIlaIl `' iIrewoírks PhoCCa ÍI : -c .c.a, ___. $ `-_,/ ;"r ,_ 'r lI jl-!.1,119''.--'..., ;4,, _ "I ;U 'I1 .I'1, '°t' I Í;, i:;;I'I,..11J, Ii't I 'Illl III The instrument above is designed for eliminating the human equation of error in recording the passage of stars. In this machine an artificial star crosses a line, and the length of time required by the astronomer in reacting to the is r. crossing definitely determined. -Courtesy Elgin Watch Co. yv r Right: In photographing fireworks it is best These to use red -sensitive plates. must be developed in total darkness. Use a large aperture and open the shutter for the length of time desired to get complete picture. J. M. Howard. 997 Science and Inventio3 for February, 1925 Phosph©regeence By RAYMOND B. WAILES. i' J' Little chips of fluorslar h=ated an an iron plate will shine like lightning bugs in a dark room. Paint a sun in a scene with luminous paint. In a dark room hold a lighted cigar or cigarette behind the sun. It will become luminous. Ice will make it disappear in the reverse way. Coat a card with luminous paint and allow it to dry; then place an object upon it and expose the whole in sunlight. In the dark room the silhouette of the object will appear. Hot water is lighter and floats upon cold water. A bit of paper coated with luminous paint will show this because the heat will cause the top part to glow. Be- low: A common medicine, salophen, will glow if subbed between glass surfaces. If one end of a Geissler tube is submerged in a solution of quinine to which a drop of storage battery acid has been added. 1 -f it will glow with a beautiful blue. If a Geissler tube is spirally coated with luminous paint and operated in series with another tube, a fair imitation of a column of fire will be had. 993 Science and Invention for February, 1925 SpecIlzllized- Clic5e19 By W. M. BUTTERFIELD HE first example shown is a closet large enough to hold the entire cleaning outfit of the household-vacuum cleaner, broom, mop, floorwax, furniture polish, etc. The closet has been designed for the kitchen, and is intended to occupy a space on one side of the kitchen cabinet, while another, of the same size and design, is planned for the other side to hold cooking utensils and for tinned food supplies. Panel board can be used in the con- struction of a closet of this kind for the back, the sides and the door. Another example shows a closet for the ironing boards as well as other implements used in ironing. One closet is for the kitchen sink outfit and is designed to occupy a space over the sink. Every housewife wants a linen closet-many are willing to sacrifice one for clothes if they can only have one for linen. Answering this almost universal call of the housewife, we show a plan by which the sacrificed clothes closet can be converted into a bona -fide linen closet. In fact, this closet was designed for a storage place for linen, although it may have the outward appearance of the usual receptacle for clothes. A rather compli- cated design is shown in which dressing table and closets occupy one whole end of a bedroom. Specialization is shown here, also, for one closet is for outer garments, the other for colder garments. There also are drawers for the usual dressing table supplies in the table and a box for shoes under the drawers. A neat bench is provided as part of this outfit. Mirrors are set in through sides above the table while an overhead electric fix- ture to supply illumination is installed. In constructing drawers or drawer -like trays, in closets, it Above: Closet for .cleaning implements. is necessary to provide for space for drawpulls and for space at the door side to pull the drawer out past the door. \Ve have shown a series of de- tailed sketches to illustrate the requirements and one method of procedure. In the ironing board details, we have shown the most practical device for supportng the board yet devised. It consists of two folding mem- bers, one hinged to the board, the other fastened to the board by means of a T-shaped metal piece sliding in a long metal - covered groove in the board. This works automatically. o o Above: View of a built-in linen closet. Drawers and shelves are shown. Right: Ironing board described in text. Above: Kitchen closet built over the sink. Below: How the edge of a door must be allowed for in making drawers. The illustration above shows two built-in closets with a dressing table and drawers placed between them. All should be constructed of the same kind of wood and stained to match. A bench completes the set. w/r// 47-0 SPINS; EDGE OF TABLE PRESS DOWN MOISTEN 11111Eg1111 HALF CIGAR BAND-, Hold the cigarette as shown, and keep com- pressing and relaxing GONE: the hands. The ciga- rette will smoke. DRAW BACK THUMB Only the front half of a cigar band is used. It is glued to the cigar so that one side of the cigar shows a band, while the other does- not. Wave the hand slightly, and draw back the thumb, thus giving the cigar A cigar is held in the right hand one-half revolution, bringing the blank side to view. and ;attention is called to the ornamental band around the cen- ter. Suddenly the band disap- is held pears, while the cigar EDGE OF TABLE in full view. Moisten the edge of a cigarette, press, it down on the table, and it defies the laws of gravitation. BENT PIN FINGER -- one BAND You need two cigarettes, for yourself and one for a No magnetic power ís required to make a friend. but when you open your full sized cigar adhere mysteriously to the cigarette case you find it empty tip of your forefinger. A bent pin pushed Close the case. When reopening through the cigar band is responsible. The it slightly and reaching inside, point of the pin rests on the tip of the you remove two cigarettes, much to the astonishment of finger. In passing the cigar for examina- edge of the table. your frt^nd. These have been A cigarette is set on the tion, the band is removed and thrown away, A fountain pen previously rubbed on the while goes concealed under the clamps. the pín with ít. coat is held beneath it and the cigarette topples from the table. Substitute a pen- cil for the pen, secretly blow upon the cigarette, and duplicate the effect. 1000 Science and Invention for February, 1925 ..[®w e Olgesec rood PARTIAL DIGESTION II2MAR GIIHSIIIERGfl ONION SLICE OF BREAD f:i o5con Chem. Eng. THE illustrations herewith show graphically what takes DIGESTION place during the process of digestion. Saliva contains < OF PGtN J BREAD IN an active digestive agent or enzyme called ptyalin which has MOUTH the power to convert all starchy ingredients into maltose, LO`J1t GIVES a sugar. Maltase ín saliva, another enzyme, acts on maltose, SALIVARY - r1N giving sugar. The food passing from the mouth to the GLANDS p. , to cardiac or upper end of the 'Stomach, encounters the secre- PV tion of two types glands. PSi MALTOSE of The one type secretes pepsin, (MALT and the other hydrochloric acid. Here the action of ptyalin 'MALTASE 'IN "SALIVA SUGAR) of the saliva is stopped due to the presence/of the acid in the stomach, and the pepsin commences its action on the various foods indicated in the diagram añd'the other enzymes, lipase and rennin, act on the ingredients of GLUCOSE (ASSIM- other food, pro- DEXTRIN ducing fatty acids and glycerine used by the body.' Very Above and to ILABLE SUGAR) the right the little absorption of food takes place in the stomach. It has GIVES ONLY IN SMALL been -definitely ascertained that?most of the absorption of diagram illus- trates w h a t AMOUNTS food occurs in the region ' of the small intestine. The action takes place in of the glands on foodstuffs is indicated in the diagram. The the mouth MALT SUGAR movement of the muscles in the'stomach walls churns the where the food food and eventually moves it out through the pyloris or is acted upon that part of the 'stomach near its connection with the small by the various _ PARTIALLY DIGESTED FOOD COMING IN CON- intestine. The food in the form of liquid chyme is here enz-ym es TACT WITH FCID CONTENTS OF STOMACH STOPS acted_on by the bile from the -liver and gall bladder by which are DIGESTION BY MEANS OF SALIVA the found pancreatic juices or those juices which come from the in t h e gland - ' saliva.' CARDIAC SECRETES GASTRIC known -ás thepancreas and by the intestinal juices.- These REGION JUICES DIGESTS WHITE OF juices are alkaline in nature, and they split 'up the pro- -EGG teins from meats, white of eggs, etc., into proteoses,- pep- PROTEINS - tones, polypeptides, and amino acids. The amino acids are in a f'srm ready to be absorbed by the body. Other. - various enzymes taking part -in the digestion are in- 1\ dicated. MEAT V V LIVER SE- PYLORIC , CRETES ' SECTION BILE . yBILE INCREASES SOLUBILITY .GELATINE OF FATTY ACIDS AND ACCELERATES DIGESTION 0, CARDIAC REGION' PROTEOSES CHYME ENTERS MILK Bile is a secretion t 8 PEPTONES of the liver. The SMALL INTESTINE secretion accumu- lates in the gall CURDLED during the PANCREAS bladder ALKALINE SECRETION BY RENNIN time that digestion FROM WALLS CREAM FAT Is not going on. ENLARGEMENT,-. OF LARGE Bile contains a OF WALL IN INTESTINE AIDS IN COM- IN MILK weak ferment. Its 'SMALL PLETING DIGESTION uses in digestion INTESTINE are dependent on the peculiar: actión of the bile salts on SECRETES PANCREATIC t h e fermentative JUICE property of the pan- creatic juice. FIVE ENZYMES aEN CONTAINS ACT ASE MILK SUGAR FATTY ACIDS AND MALT SUGAR GLYCERINE .1l MILK MEAT WHITE MILK INTO GLUCOSE CURDLES OF EGG THE MILK ASSIMILATED PROTEOSES. AND PEPTONES BY BODY 4, STEAPSIN IENTEROKINASE FINALLY INTO AMMO ACIDS USED AS FUEL AND RE- ABSORBED BY SYSTEM - BUILT UP INTO COMBINED INTO FATTY, FLESH 8 MUSCLE AMYLOP- DEPOSITS USED WHEN BODY_IS STARVING CONVERTS ENZYME CHEESE SUGAR '1SiN IN PANCREATIC DIGESTED CHANGED INTO JUICE INTO DIRECTLY GLUCOSE ACTIVE TRYPSIN T h e alkaline WHEAT RYE LARD content of the ABSORBED STARCHES o ti- intestine c COMPLETES DIGEST - In the above diagram an attempt has been tains the enzy- .OF MEATS 'AND made to illustrate what enzymes act on mes trypsi-a, foodstuffs, and how those are amylopsin, steap- OTHER PROTEINS foodstuffs i split up, producing assimilable end products. - sin or lipase, USED AS FUEL IN a n d pancreatic FATTY ACIDS rennin. MUSCULAR ACTION MALTOSE 8 GLYCERINE Science and Invention for February, 1925 1001 agIlc for Every.11®dbY By PROF. JOSEPH DUNNINGER NO. 23 OF A SERIES V. The magician has an ex- = Three cards are shown. tra large billiard ball in They are placed face his hand. He invisibly i downward on the table. tosses this on to a On turning them over the stand. The construction center card has changed of the stand demonstrates to a blank. A corner of ' a card is cut off ,. how the trick is / c performed. When - and glued to re- another so that it the assistant forms an en- leases the string velope -like the air bag corner for a inflates s the blank small rubber card. A Tá balloon. ` l;y , 61- sa Cl'- e3 .:I r irtsE Íi líiS"[1''"1 RED SMALL BALLOON l PIECE PALMED RUBBER BALLOON TUBE IN INFLATED , STEM AIR BAG BALL PALMED-' SPRING STRING IN HAND OF ASSISTANT OFF STAGS 1 i I SPRING' WHEELS WAND HANDKERCHIEF Sit U 11' 411101111111 THIN THREAD STRING TO FLOOR A. o_- BALL FLOATS THRU t -SPACE . ASSISTANTS HAND IN HAND OF - IN THE HANDS ASSI5TANT OF THE OFF STAGE MAGICIAN J Z./ s, .. . The magician The performer holds a large mag- loads a handker- net H i s assistant chief into a pistol. A walks off with a large wand is suspended in ball and releases the midair and the per- ball in air, which floats to- former fires at the wand. ward the magnet. Actual. The wand contains the ly the ball rolls along two t handkerchief. An assistant thin threads. pulls it into view. '1002 Science and Invention for February, 1925 Soap Do_ AcI®w -cp o 4 - 0 -'. _ .J. n 'b";.7 NEG I. DARK BACKGROUND , IIII1II I II Vl II .P..t1á11 í '1 I'1. . ,'. f '.i,° .1 1111111# í.l 1111"1111111 ,I1,'1° . ,I ,li '' I. I ^- ti1l1¡ i1 .. yII í l !' 13.1 ,, ' ° 111#11 . I.I I1-11, .'°, I : ,I¡ilíl1.11.0_ ji ' / NEGATIVE I Here is a movie actor whose head is made of soap. In filming a recent fairy as shown at the left, and dressing it up to imitate the character to be shown tale, the director came face to face with a very serious problem. He could The picture of the doll was filmed against a dark background. The other find no actor of sufficiently grotesque face and form to act a certain part in characters meeting the doll were also filmed against a black background. the piece. As a result an ingenious art director hit upon the scheme of The two were made on separate negatives using only half the film. Both carving hobgoblin's head from a bar of soap, placing it on a small frame negatives are printed on same positive, giving a single picture.-L. J. Wilson. Tachont e4ek- FeDir WaIlkews EFrl ;_:IlIls f /S Il£('e ". ti ` t i .///;11~ 71.6A_ f ., .11 , 1' . The tachometer shown in the above illustration For night walking this device uses two electric The use of a dual air chamber in automobile reccrds the speed of the machine being bulbs in parabolic mirrors attached to eye tires allows a thicker tread and much easier measured, showing variations in it. glasses. (Author send address). riding. Science and Invention for February, 1925 1003 ,,X0F2laiMir a.;or MoTe GambIlerr95 1 ITEck_1) ° rpOo 5e G By MARK MELLEN ff Man Who Fooled P. T. Barnum The o yttttl,' - .. ON this page the show a number of mechanical devices and contraptions that are often used 1111 to fleece the would -he "wise guy." There are The advertisement of the Tumble Bug reads: "Get the bug and get the quite a few concerns manufacturing the devices jack. This is a two way store under shown here. For those in the "know," blueprints control at all times." Pressure on a are supplied demonstrating how the devices work. screw regulates the size of the slot, The story about the Goddess of Chance which gives making it impossible for the bug to each and player an equal opportunity win- Pop in the bucket shown above is a enter the lower end of the trough. every of direct descendant of the old Huckley ning a large prize is pure bunk. One might just as Buck family. It looks easy to win- r svcll place the head and shoulders of a beautiful and it is, when the operator wants you woman on a stand as illustrated below, and put the to win. The ad states that "the outfit sack of easy money in her hand. Then as the can be regulated and demonstrated by crowds try to embrace her the crooks do their work the operator at all times." By tilting the bucket a little less, the operator by removing the gold from the pockets of the swell- can cause you to win or lose. ing crowd. Of course, the gambling devices illus- trated are more legitimate. They are painless methods of extracting cash from the pockets. The ir gambler is not a philanthropist. No doubt he lets you ruin two or three or four times in succession, or he may even let you win for one or two days until you have imbibed the spirit of the thing, and then one day "luck" runs against you, and you lose a little more than you won. You try to The advertisement of the Chinese recover Dice Box reads: "Shake the dice the loss and continue to lose more. Then without removing the cover from you become convinced that the Goddess of Chance never The trip dice box "trips" the dice as the box and name the faces on the smiled at you and are about to forget the they are rolled out and causes them to dice that are up." A dice box of game forever when you make a "killing," and reg- turn over, thereby frustrating the- ef- this nature is well worth the price ularly thereafter you win once and lose a dozen or forts of anyone who may try to slide charged for it if you can induce any. more so unless you them out instead of rolling them. one always times, know more about it titan to bet with you. You the other fellow. keep out of the game. Suckers think the game must be on win. The dice can only turn over the level. They don't realize that the once for each shake of box. In the dice may be controlled after they leave two shakes the faces on the bottom the box. will be on top. The hand cage illustrated above is generally used in playing hyronemous or hazard. It is seemingly impossible to manipulate the dice inasmuch as they are kept in the cage. cage. in as If there is any doubt your mind to An electric control for the hand cage may oe purchased whether or not it is practical to control dice for a mere addition of $50.00. The dice in the cage by means of an electric current, we advise shavings and as usual the sucker that the illustration below. The are loaded with steel you look at has no chance. The rubber dice mat illustrated below advertisement reads: "The electro -magnetic the cops rather than the players. coil is placed in a wooden case 9 inches is used to cheat square, 2 inches deep, and is fitted with an Elimination of noise prevents officers of the law mak- extension cord and connecting plug which ing an arrest-or a collection. will fit any ordinary light socket. The mag- net is controlled by an extra heavy switch and will pull through one inch of wood con- trol'ing a space 6 inches square." The platinum filled transpar- ent dice illustrated above is used where suckers cannot be steered into an establishment containing a magnetically con- trolled dice table upon which the player has no chance. 75\ The dice here illustrated is loaded with platinum. Being so loaded the cheater brings \ his suckers to any place at all, and if they are willing to ºC 1 s bet against him, he removes their surplus capital. .. ,-- --.7!'cw¢:w:. 1004 Science and Invention for February, 1925 cr,:,ha >.. :.,es r.r.i,...... :n,..xmrwr.h4A«1.TKen:'v Oufillarffig ` McA00 Tr Gpeed,slew Specially Prepared by GEORGE ARTHUR LUERS WHO, with any sporting blood in their veins, can resist the lure of a snappy, low hung sport car? Probably every one of us has at some time or other had a burning desire to own and operate a car of this type. The cost of such an outfit, ready built, has deterred most of us from the realization of this dream. However, we are showing on this and the opposite page just how a fast auto speedster can be made from a Ford chassis and a few parts that an ordi- nary mechanic can make. A few inquiries in the proper direction will soon make evi- dent the fact that a second-hand Ford chassis can be purchased very cheaply, sometimes as low as $15.00. 5 DIA. Z DIA. -- The first operation is to place the engine and chassis in good mechanical condition. Clean it thoroughly and when finished, give 000000 it a coat of black enamel in order to pre- DRILLED HOLES UNIFORMLY serve it. Before starting work on the body, 3" must be changed. The main idea INCREASING 1.8 DIA the engine is to reduce the weight of the reciprocat- APART ing parts, namely, the piston and connecting rod. This can be done as shown in Figs. 1 and 2 herewith. It is advisable also to use two gaskets under the lower crank case cover, which increases the oil supply in the REAR FRONT AXLE troughs. AXLE The next work is to undersling the chas- sis. Strap iron bent and drilled as shown is the only necessary material. The details for the front and rear axles are shown in parts in Figs. 5PRING Figs. 3 and 4, and the various 5, 6 and 7. A brace which will make the front axle more rigid is shown in Fig. 8. BRACKET-- RADIUS ROD In order to undersling the chassis, it is necessary to cut five inches off the frame, BRACKET as shown in Fig. 13. The steering gear 3" must be lowered. Use is made of a wedge, 8 IRON Fig. 9, and extension straps to the steering '-IÓ" LONG post flange, Fig. 12. An oak dashboard is to be made. Fig. 10, and placed in position with braces, Fig. 11. 8" LONG TWO EACH DIA. 4 HOLE FOR SPRING PERCH g DIA. 6. 8 STEEL ROD o 3--+--2 V- -.171 6 HOLES THREADED II" é i. - TWO -OF IRON PLATE 2 FRAME 16 YOKE BALL Na 2127 B MADE FROM RADIUS ROD L * FRAME 15 SPLIT AND RE-RIVETED BRAZE /' 28" BALL AND STEERING FRONT JOINT AXLE-r,AXLE - CUT 5" OFF LENGTH OF FRAMES -15 = 1 TWO -IRON 'Z TWO-Ih0 BRACES SUPPORTS Science and Invention for February, 1925 1005 AFTER the engine and chasis changes, illustrated on the opposite page are 2 19 completed, the body must next be 20 GALLON,GASOLINE built. All the details are given herewith. / TANK First, a frame is made up, Fig. 14, using screws for fastening together. Foot boards are shown in Fig. 16, which are to be fas- /13 tened with braces made of strap iron as shown in Fig. 15. The body and the cowl are the next consideration. A pattern is given in Fig. 17, which should be repro- duced in full size on a large sheet of paper. This pattern can then be placed over the metal to be used, and the latter carefully cut tb the correct size. This casing is to be 9 I. 15 16 la 17 20 3 secured to the frame at the edges and to ,.i the dash by small large -head nails placed 103" one inch apart. The metal may be cut in one as in several pieces, piece shown, or The above illustration shows a complete assembly view of the motor speedster. All of riveting together at the junctions. For ap- the changes or new parts are numbered, the numbers corresponding with those given in pearance, it is desirable to bead the edge of the other illustrations. 'A sixteen valve engine head, sold on the market, will increase the the metal by turning it over a stiff wire. The power remarkably. details of the seat and upholstery are given in Fig. 19 and of the tool box and gasoline tank support in Fig. 20. Fig. 18 shows how disks for the wheel can be cut from gal- vanized iron. Z. STRAP IRON One other point that is desirable to ob- I°x2' 1 I"x I` I` serve in order to get the greatest speed out x24 -BDIA. of. this car is the muffler. It should be inside 69' removed and the shelves taken out. -.,.. _. ' This procedure will reduce the back pres- l sure and increase the power of the engine. After the entire assembly is made, and a 4-72 ,4--I I=+ ---13= ..-j4 2 .---131. special twenty gallon, or the regular ten gal- lon tank, placed in position, the entire out- fit should be carefully painted. First use 't, a lead priming coat, sandpaper it and use = one coat of color enamel. Rub this down with steel wool and apply a second coat. . again rubbing this down with steel wool. One or two coats of varnish give an excel- lent finish. A white ivory body with black trimmings makes an excellent finish for this NAILING STRIP car. RADIUS Of GAS TANK 17 6-8"MOLES 24 GAUGE GALVANIZED IRON 7_ 24 GAUGE SHEET I OR GALVANIZED IRON \ 'APPROX. ` OUTSIDE DISC INSIDE DISC STRAP LOOPS 6« OAK - GAS TANK STRAPS PANTASOTE IRON 1^i 16"-=-+,i 6 = I,i - i CURLED - I1 ------.: _ HAIR -Q-k- l - HINGES ,,....,.r...,,_ 14" i _ F_IL-- -y-_----l1._.4-_ 30" I i 19e 14 1006 Science and Invention for February, 1925 EmeTgen e y Fool BwIlJ.ge -,?=."t.,..' rv-'+uF'' f- r -N A"'IV7V/.J;Yi/ ^! i..,\ ',` '¡ Il, =vr_ dlitjij 11+19:114'ti . , 'M CgRRYING BRIDGE BV1l1NG In many of the more sparsely inhab- The piers are made of two jumping ited districts of the country, particu sticks as shown. At the center they larly in the west, there are many are lashed together with ropes or small streams over which no bridges simply stuck in the ground. An iron exist, and which cannot be forded on link over the tops support the planks . account of the bad approach or steep which form the footboard. Rope lash- sides. The temporary bridge illus- ings from one set of poles to the next trated in this article and adapted will increase the stability. The bridge from war -time tactics, will be found can easily be run across a stream by exceptionally useful for throwing an pushing the poles out forward, lashed impromptu crossing over small and linked, as shown. streams. -P. C. v. Petegem Sman MIlci°®eic®pe from. (Maw, TF)SeacQl5 lm, iI1111ObM1.PIvuIPlm.mi bi ummvunplamu°nmlpP'rppy'. P.I moonuniminii j mo,...... ,..,..; GLASS TUBING' PINHOLE li HUMAN HAIR SOFTENING POINT OF STRETCH SOFTENED GLASS iri GLASS TUBING INTO A FINE FILAMENT MATERIAL CARDBOARD O BEAD ulllll i i, lgnll'IC I!I I)4 a BREAK FILAMENT INTO TWO PIECES. INSERT BREAK BEAD INSERT LENS INTO PINHOLE INTO FLAME TO OFF elíA1 OF FILAMENT IN CARDBOARD FORM BEAD es 1 -HAIR GUMMED 1rst PAPER LENS k,.l . PLACE HAIR DIRECTLY OVER EYE BEHIND LENS AND HAIR USING "Rob\ CENTER OF LENS. FASTEN ARTIFICIAL LIGHT WITH GUMMED PAPER USING NATURAL LIGHT © The lens for this miniature telescope is made by drawing out a glass rod over appear of about the diameter of a pencil. Several of the beads should be made, a flame. When the softened rod is stretched and broken in two, one of the and the one being most free from bubbles, should be used. Selection is made fine ends is held in the flame again, so that a bead is formed. This bead is by experiment. Since the lens has an extremely short focal length, it will be placed in a pin hole of the proper size in a sheet of cardboard. If a hair is necessary to place the object directly on top of the lens and to hold the lens placed across the top of the lens directly against it, as illustrated, the hair will as close to the eye as possible. -Edw. Kuwatch, Jr. Science and Invention for February, 1925 1007 ir^rrsrsa-rrr oscrscDciv'Y`CULvrs^:I'lrrrr. 2srir.,"4^r.r.rrrt4~a^tv»vrrvrFri^rr.r:1" ^ W--"TO J 1 ./ s' rreracsr..nrr.orr...rr r-ssr .rrv. rsa vv- /rrrYrtrsrir^rr.r-r This department will award the following monthly prizes: First prize, $15.00: second prize, $10.00; third prize, $5.00. The purpose of this department is to stimulate experimenters toward accomplishing new things with old apparatus or old material, and for the most useful, practical and original idea submitted to the Editors of this department a monthly series of prizes will be awarded. For the best idea submitted a prize of $15.00 is awarded; for the second best idea a $10.00 prize. and for the third best a prize of $5.00. The article need not be very elaborate, and rough sketches are sufficient. \Ve will make the mechanical drawings. Use only one side of sheet. Make sketches on separate sheets. Lk n idk Dispenser Priirc lS Washer The ` R FIRST PRIZE $15 SECOND PRIZE $10 THIRD PRIZE $5 PET COCK TIRE PUMP HOLE. IN TIN CAV OLD VALVE STEM nit» = '.. E,. ,.. :2ttl il 4 ----1 III i II,,J,i91í"""¡I'I` jll d,,,r I'I,liury M 9;r.l II A very handy print washer for the amateur photographer can be made as shown above. A hole is punched the COPPER TUBING near the bottom of tin can which is then placed in the washing tray. I.. Liquids in large cans can be readily dispensed Water is allowed to run into the can and to by using outlined above. Air pres- escape over one edge of the tray. The hole the system PACKING NEEDLE WITH EYE sure developed by the tire pump forces the in the can creates a current of water that FILED AS SHOWN liquid out. The flow may be stopped when thoroughly washes the prints. Rubber bands will repair bicycle tire punc- desired by the pet cock. -L. J. Smith. -Author please send name. tures. Coat the bands with rubber cement. insert in hole, remove tool. Cut bands flush TIlRRlIe GIlass with tire when dry. -Milton White. Hammer DlIlnk Magne4Ilc 5nake SANO For driving nails in out of the way places, drill a hole in the hammer as shown above. The nail is held in position by a bit of bees- a51 wax. It can then be driven into the wood without the usual b-uising of the fingers. The time glass illustrated above will serve When the nail is started, the hammer can many purposes. It consists of either a glass readily be removed from it. tube or test tube, heated and drawn out as -Florence E. Moore. A piece of tinsel suspended as shown above shown. The amount of sand is determined will perform violent contortions when current by experiment. -F. R. Newton. is passed through it. Also try reversing the Elg Trick Printing Mask current. -S. Leonard Bastin. Sundering Thao n SOLDERING LIGHT AT HOLES -'ff.7 IRON q HOLE GAS JET I HOLLOW BRASS ROD to HOLES Hold an egg as shown above for a moment or A satisfactory printing mask may be made A soldering iron made as shown above can be two. The yolk will settle and with a little from an envelope as shown above, cutting the quickly and easily heated over a gas jet. The manipulation the egg will balance perfectly. face of the envelope to the desired shape. flame ascends through the brass rod. -C. L. Walter. -A. P. D'Ambra. -George A. Coates. (This department xt'ill be continued under regular $1,000.00 contest ruling next month.) 1008 Science and Invention for February, 1925 ^r .trrsJ'r. -r^r r- rr ...-.s. r.r.x- nr ciYer.ttrrrr.r..sCqr.uey...swoe2ottaa'19:0oa-."rwavGaaa*-ra»^. ,( . ¡ , ,RThJJK. . , --t t-+,a v r- Ltf 1 ri 1/ r i Edited by S. GERNSBACK Novell EmperrIlment5 viith Heat By EARLE R. CALEY, B. Sc. A strong solution of An interesting ex- cobalt chloride in al- periment in freezing cohol when placed in water may be per- SOLUTION a tightly stoppered formed by melting IN SEALED bottle or a sealed tube, together six parts of GLASS- serves as a heat indi- tin, ten of lead, and \WATER TUBE cator. At ordinary eighteen of bismuth. FROZEN temperatures the solu- Powder alloy UI, this tion is pink, but upon finely and pour it being heated it passes into a beaker con- through different taining eleven parts shades of purple, un of mercury. T h e til near the boiling temperature of the point of water, it be- mixture will drop to comes blue. 1 6 ° Centigrade, and a walled ., thin I, test tube of water placed in the mix- AI ture will be frozen. Cards coated with chemicals will change color when heated. Cobalt chloride changes from pink to blue, -obalt iodide from pink to green, mercuric iodide from red to yellow. POTASSIUM BICHROMATE SQLUTION CALCIUM CITRATE I i ali SOLUTION //, -->/A7 7 , },:/'"P:ts "Hypo" when melted in a flask which is A cold saturated solution of calcium citrate will be Place crystal of iodine in stoppered test then corked will remain liquid. However, precipitated by heat and potassium bichromate will tube. Heat produces intense violet col- if a wire holding a bit of hypo is introduced 1 be dissolved thereby. Put the substance in test ored vapor. Cooling reverses the phe- the flask, beautiful crystals will form. tubes with beakers of water to give temperatures. nomena, the color weakening. /\ into 1 {t Papew lileadew jaw R.aca CORNER OF SMALL CLOCK OLD ENVELOPE SPRING STICK 3,8X1 POST4x4" _,.T.m,,, ''''"''''' EMPTY JARS A piece of lum- y \ ., MOW her 4 x 4 in "ffiff: which dowels are paced as shown at the PIN y1 AS right makes an 1 excellent rack ' HAND for holding I p'Igi Ill\" i..:r. II 1,.1,;- empty mason I jars, so that rJI II'IIII. be 11'' ' they will ¡`t "- - out of the way. qí-,i -E. M. Quim- Alf I by. II 11114 dC =; (_- Corners clipped from used envelopes make A small clock spring mounted as shown at splendid reinforcements for several sheets of the right when provided with a loop of wire paper clipped together as shown above. for holding envelopes makes an excellent letter --S. Schlesinger. scale. (Author send name.) - Science and Invention for February, 1925 1009 Readers Forum mmmm,mnn,mnmmmnmmmmmm,2 THE INHABITANTS OF MARS Lord." Science says that life started with a was 3 single cell. If science is correct then that Editor, Science and Invention: SCIENCE AND INVENTION desires God's way of creating. The Bible does not say I am rather a "bug" on astronomy and that to hear from its readers. It solicits com- how long each day of the six days required to is the main reason I have many of your maga- ments of general scientific interest, and will create heaven and earth were. Why could not zines saved up. I would like to know why sci- appreciate opinions on science subjects. The God have created everything in an instant? He entists say that no people inhabit Mars. If the E arguments pro and con will be aired on this chose the way we call evolution. That, man at Mars may earth has inhabitants, why not Mars? page. This magazine also relishes critic- one time looked more like an ape than like a man be a planet but it still can have people on dying isms, and will present them in both palata- is absolutely proven proof: The human skull used has to do with it. The it. The gravity nothing ble and unpalatable forms. So if you have to br nearly flat across the top; man had a larger, people are built to endure. climate, most likely the anything to say, this is the place to say it flatter nose and a heavy set jaw, much like the seas may be like very large canyons. Dried out in. Please limit your letters to 500 words ape of today. Man was covered with a coat of \Vhen Mars was nearest us last, August 22nd, and address letters hair, and would be today if it were not for heard sounds your to Editor-The some scientists reported having queer Readers Forum, c/o Science and Invention clothing. There are many other things that go had seen greenish -yellowish flashes. Other and Magazine, 53 Park Place, New York City. to prove evolution. The kind of evolution that scientists scorned it. You must remember that W..1. Bryan makes fun of has nothing to do with the inhabitation idea is only a theory, not an actual um,1,umuu®®nuwuuuuw,11uuwwm,. science, and never did have. Any broadminded proof. I believe an astronomer only knows what person can see that evolution and the Bible agree so his telescope can show him. Is there any with each other yet there are a few who do not powerful that it can detect people? Cameras only summer; so they are in sonne way dependent on want to understand and will continue to think show blurs of Mars. the temperature In the polar regions. If they are hoar -frost that evolution is "unprovable," etc., when a JESS WAY, or snow, they arc condensations of little thinking would set them right. New York City. water vapor, and when they disappear, there must R. II. MEEKER, (There is one group of scientists who believe in be sufficient heat to melt then, but the normal Holland, Mich. the inhabitation of Mars. This group was undoubt- temperature of an unprotected body at the distance (This opinion on the part of another reader edly led by the famous, now dead, astronomers, of Mars from the sun is about 32 degrees below is likewise by many evolutionists the entertained who Percival Lowell and G. B. Sehiaparelli, and zero Fahrenheit, and since Mars cannot retains can abide at once by the laws of Science and other group does not believe in Mars' inhabi- Inudt heat because of its thin atmosphere, it could the Church at the same time. A radical, sane be assumed ice tation. For the sake of balancing arguments, that the polar caps are not snow, thinker is a worthy individual and a man who both in favor of Mars' inhabitation and against but may be carbon dioxide deposits which con- upholds his belief in the face of odds is doubly that view, we roust first take into consideration dense into a white substance at a temperature of minus worthy. Those who profess to be scientists and the known facts concerting this much discussed 109 decrees F. The mean temperature of then take a biased view of everything else, non- planet. Mars is about one and one half times the planet Mars is not assumed to be higher than scientific, are not worthy of consideration and earths are. 48 further from the sun that we on this degrees F. This would make it difficult for the same holds true for over -zealous religionists Its orbit is very eccentric, and its distance from vegetation to grow, unless that vegetation differs who can see nothing but from their own point of the sun varies as antch as 26,000,000 nn7es. At from vegetation as we know it on this planet. and treat all others who do not agree The observation, its nearest approach to the sun, Mars is more than editors believe there are as many argu- with them as bigots. Fortunately, the world is at ments 128,000,000 miles from that luminary, and its in favor of the inhabitation of Mars as made a vast majority the type men those of of of similar greatest distance 154,000,000 miles away. If we against it. Scientists like to speculate and to the writer of the above letter. find that it we see no reason take the mean distance of Mars, we why other planets should not be It is good to remember that the other Mans is would take light 12y, minutes to travel to the inhabited the same as ours. Should anything of right part of the time. The rational individual 11 more planet from the n. This planet has a very light a definite nature be learned at any time, listen to and correct opinions if he knows heat it will a atmosphere, and consequently the which the readers of SCIENCE AND INVENTION MAGAZINE little more about the subject than the person with obtains from the sun is not retained, and there will be the first to get the information. whom he is holding a conversation. He must, must be extreme changes In temperature. Mars Summarizing, one may state that it is now be- however, his mind to the logic lieved open own and rotates on its axis in 24 hours, 27 'ninnies and 23 that water and vegetation exist on Mars. reasoning qualities of his opponent in a discus- seconds. This stakes a day on Mars approxi- Air is present, and perhaps some form of animal sion and accept those parts of the arguments which mately 40 minutes longer than our own day. Its life exists there also, which if it progressed along best his own and overcome his objections. degrees and the lines axis is inclined to its orbit about 24 of evolution on this planet, must be Again we repeat as we have done so in past 50 minutes, which is a little more than the in considerably more intelligent than our own group issues-"One does not have to overthrow the is 23 degrees of human beings. clination o7 the earth's axis, which laws of state and religion to become a scientist" and 27 minutes. Mars, therefore, has seasons -tire above letter confirms it agahu.-Editor.) much like ours, but the seasons which are very JIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII11111111111111111111111IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIL are slightly more marked and are nearly double the length of the terrestrial period, because it takes DOESN'T LIKE JOKE EDITOR Mars nearly two of our years to make its journey Editor, Science and Invention: once around the suns, which would be one year Some time ago I sent you a joke about a doodle for Mars. Its seasons then are six months long, The Experimenter bug. I have never heard any more about it. I while ours art but three. As on the earth, has come back! If you are one of the think it's about time that you give us fellows there are torrid, temperate and frigid zones, and one hundred thousand readers of the old that never had an education a chance. I can't like the earth, it is furthest away from the sun; ELECTRICAL EXPERIMENTER, you will no see that it's necessary for a man to be a pro- Cohen there is summer in the northern hemisphere, doubt be glad to hear that the EXPERI- fesses or a college teacher to win a prize. I the temperature on the planet is much MENTER is coming back BiGGER AND think I can write as good a joke as any college warmer because of its proximity to the BETTER THAN EVER. PRACTICAL ELEC- professor and then some. I think it's all a sun. The main surface of the planet is TRICS has been changed into an entirely swindle. Take the joke I saw in your magazine reddish yellow in color, and there are patches on new kind of magazine entitled about radio sounding like a cook snoring. Now it that are blue, grayish green or gray, or a com- I know that no radio set ever sounded that way. bination thereof. Sehiaparelli, the eminent Ital- I've asked lots of people who have radio sets if ian astronomer, pointed out that there were green- The Experimenter their sets ever sounded like a cook snoring, and ish streaks all directed to so-called seas. He called In this magazine which has been greatly they all said no. I don't understand how you these streaks canalli, which when properly trans- enlarged in point of contents1 illustra- publish such jokes when good jokes like mine you lated means channels, but when it appeared in tions and circulation, you will find the don't even look at. English publications, the translation was changed following new departments: N. COMPTON, to canals. This immediately started the contra. Experimental Radio Greenville, Ohio. versy over the inhabitability of Mars, because can- Experimental Chemistry (No doubt you feel peered because we returned als as we know them, are artificially produced, and some of your jokes as unavailable. The reason if artificially produced, then intelligent beings must There is an entirely new treatment of for our rashness was that your jokes needed an have built then. Another view entertained is radio containing experiments only. 90% explanation, in other words, they were very deep of the magazine that these so-called canals are vegetation canals. contains pure experi- and the joke part could not be easily perceived; drawings of the canals were given in the ments written by the foremost authorities in fact in some of these one could not see the The in respective issue of SCIENCE AND INVENTION MAGA- their fields, also a monthly joke at all. Now if you will give cis some really December editorial by the writer. ZINE, on page 771. Here twenty-two triangular good jokes, we will be glad to publish them and shown, which were first ob- A fine roto -gravure section is now pay you for the privilege at the saute time. Don't canal terminals are added at the Observatory at Flagstaff, to brighten up the magazine. If worry about its not looking at jokes. We look at served Lowell you want the year 1894 and '95. On this snap the experiments, this is your maga- everything, and this answer proves that your Ariz., in zine. light areas are continents and islands of white, jokes-alas-were also read personally by the Be sure a red and yellow inorganic soil. The dark areas to reserve copy from your writer. And believe us it is no joke to wade news -dealer before the issue is sold out. are sea beds and lake beds, and the vegeta- through 3,000 would-be jokes every ,noth!- dry THE EXPERIMENTER will be on sale tion assumed to be rivulet valleys, all of Editor.) canals are at all newsstands which, get their dark color from the residue, beginning January 20th, black organic soil of the planet, which shows more 1925. QUESTIONS JUDGES' OPINIONS conspicuously when wetted seasonally with mois- and Invention: Tice dark Editor, Science ture from the polar taps. triangular canal Gerrn s bac14. About eight months ago I sent in three articles terminals shown at the seashore line, are now Editor to your magazine. They were returned to me held to be dry organic black mud deltas, the last marked general interest." Imagine 'my the "not of deltas made by once running rivers. That surprise when on picking up the November num- sea history deltas, t11111111111IIIIIl11111111111Illlllf IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIiU last Martian wrote its with ber of SCIENCE AND INVENTION I found an article drain sumps and valleys of dark soil is the as- that was practically a duplicate of one of my sumption of Lowell and Sehiaparelli. The same As to seeing Martins through a telescope, this articles which was returned to me with reason applies in the case of Lake Bonneville. The only at present is impossible. An object to be seen on above marked. Evidently your idea of "general difference is that the Martian drain sumps are Mars must be at least 30 miles square. Editor) interest" has changed. dry, while those on Lake Bonneville are still in Your distinction in your Gold Cover Contest operation. It is probable that the only water seems to be extremely fine. In the contest an- appears is that is BOTH SCIENCE AND RELIGION which on Mars which obtained nouncement you gave a square box covered with from the polar The few clouds which can caps. Editor, Science and Invention: gold paper as a suggestion and give sixth prize to a be seen most of the time, may be due to water I have just read the letter by A. M. Riordan round box; you suggested picture frames and give vapor, as the clouds we see ordinarily are, or they in Readers' the Forum, and would like to make a prize to a picture frame which has a drawer for be but in either ease, the a may even dust clouds, few comments. stamps as an addition. It seems to me that these planet would have to have air currents to move In the first place Mr. Riordan does not un prizes come under the list of those excluded in those clouds. Consequently one can reasonably derstand evolution. That is obvious from the the prize announcement. assume that Mars has an atmosphere even though way he writes. Evolution does not conflict with RICHARD WHITTINGTON, the atmosphere is scant. The famous polar caps the teachings of the Bible. God created man- Crawfordsville, Ind. are of uncertain origin. They appear in the but how? In one day, yes-but bow long was winter season on the planet, and disappear in the that day? "A day is as a thousand years with the (Continued on rage 1032) 1010 Science and Invention for February, 1925 surrr.r.r.r .cr.cf. crr.rr s..rrfsfs.rrfsr.r.ssfsvffsrfrff RzCó.Ilo PfietoTlzi Y .1_0 W e . t m -5. , I t ,gli d _..og,,. o rrrw.vair: . ,, i C Ino 'n o n , .11y - 4 A blind radio genius of San Francisco. Harry Scott shown k - with a set he con- , structed using the new Braille blueprint sys- Above: The thriving little town of Larch- tem which brings the mont, N. Y., now boasts of a very efficient joys of radio con- and complete radio broadcasting set for the struction with- use of its Police Department. With a range in the reach of cf 600 miles, a law breaker will have to those afflicted. move quickly in order to escape capture. To those not Left: Thanks to a decision handed down acquainted iy the District Court of: Appeals giving with the sys- Elm credit for his invention, Dr. James Har- tem, it seems ris Rogers, famous radio inventor, has won slow and tedi- ., .r an involved controversy between himself ous. However, and the government. The aged inventor, this is not the famous the world o'er for the development case. cf the underground antenna, is shown ad- justing the submarine radio transmitter, by the war. ' used Navy during the ' r - .} f s :: J.! \t Talk about novel horse-built - Z ,i ,},-" f radio receivers! The one - til [`/X shown at the right is made .... _.rl -' , entirely from sour mi k-a casein product. Coloring pigment of the desired tint is added before the milk I hardens. In this wa- a beautiful effect is obtained. ' t` Science and Invention for February, 1925 1011 A il ew One-WG135 Splendid Addition to New York's Broadcasters. n .I .4 '. o K41,41 . - . « a. óeaaW==-'o t /4' ._ - - -1 `iy''..- 1. -: .- Operating on 316 meters, the law de- i that no devi B__ mands ation from the allot- I ted wave -length be 1 rtt The engi- ' - allowed. the ' ` neer checks up ;\ wave -length daily. I.ip..-- 1 High up above the street resting upon the roof of the Gimbel antenna masts r Brothers' store in New York City are two beautiful I !o 4 through ¡i T supporting the large aerial from which the programs pass . "'"-- 01.1 space with the velocity of light. Ia :41 1 _=9. ,eft' r . k% - iy r, f-.. . wa ªw y.._ i ` -- F ,. The inte:ior of the beau- I 4i :ifal studio where op- 7o-tunities are afforded f. :hose with an ambition to perform before the microphone. The entire studio is glass -enclosed. \\ GBS is the second radio broadcast sta- tion to be operated by the Gimbel Bros' Co. The other is the well-known WIP located at Philadelphia. Above are shown the licensed radio operators who listen in continuously during the broadcasting of pro- grams. To the right, is another corner of the artistically designed station. One of the many novel features is that the station is operated entirely by storage batteries, thus eliminating the annoying hum usually ac- companying the use of generators. In this way clearer programs are the result. 1012 Science and Invention for February, 1925 ` iran5-A4Ilalnvefic Pho RZdlfiegiranel§ THE -TUBE DETAILS OF HOW PHOTOS ARE NOW RADIOED BACK AND FORTH WHICH SOLVES THE PROBLEM By LEON L. ADELMAN THE era of rapid transmission of pictures from country to country by means of radio is here. Across thousands of miles of space, -_..eaoi.-- hurdling oceans and continents alike, this agency we call Radio has s been harnessed to carry the images of places and personages and happen- ings in one corner of the world to places and people in distant countries. The full extent of this accomplishment cannot be foreseen at this time. But we believe it to be a great forward stride in radio science, and an important contribution toward "localizing" the news of the world. s ri -- A3 we study the forward marches of science, and their effect of r, steadily shrinking the world to what will ultimately become a single, big community of fellow humans, we must admit the growing necessity for the development of a universal language. Until this new process is worked out in its tedious way and accepted by the nations of the world, Photo -radiograms, which speak the truly universal language of pictures, will go far to bridge the gap that different latitudes and tongues have interposed between the peoples of this sphere on which we live. There is an old Chinese proverb to the effect that "One picture is worth ten thousand words." This is as true today as the day it fell from the lips of the Chinese sage, for, since primitive man made his 1 first crude drawing, pictures have been in constant use. So innate is Captain Richard H. Ranger, the developer of the sys- our "picture sense," through centuries of cultivation, that one good picture tem and the inventor of its unique features, is shown may truly convey to us, at a glance, an idea or story that would require with the "electric eye," the tube which is responsible many words in the telling. It is not too much to suggest that the trans- in a great measure for the successful operation of the mission of pictures across the world will play an important part in apparatus. Not only photographs, but all kinds of Í printed matter such as newspapers. typewritten letters, promoting world peace by making closer neighbors of peoples living on and manuscripts are easily reproduced radioally. opposite sides of the earth. * * *-Statement by General James G. Harbord, President, Radio Corporation of America. "Truly, a great achievement has been accomplished by the untiring efforts and perseverence of that small minority calling themselves Engi- neers and Scientists. One cannot begin to imagine against what great odds these promising results were obtained, but one can readily see that it was no small task to maintain absolute synchronism between apparatus 3000 miles apart." 9 MILE RECEIVING fr.' - ANTENNA AT RIVERHEAII,L.L , Zr' II /. iy.- x-sy J PORTRAIT RECEIVE FROM ENGLAND `! . s.,, r 1 VIA RADIO% ( w ,ds ' A 1 _ -d4 no ,II STREEr 11 I 11-17 NEW YORK_ i{{{ I' v ,. . r f'lI e 'Nev TAPE RECORDER Ti +~ 911V"-- ¡ CHECK SYNCHRONIZING : ; , ;,£ 11, é PORTRAIT 411/ . -;II ., --_...=y r++ be, :, RECEIVED BY MAIL >x d', tyf, - ++wl 11 . r E'$ By comparison between an 1 ' original and transmitted #ta photos, it is at once seen that the outline, the shading f I AMPLIFIER and tone effect is realistically portrayed. To the right I' u É is shown the photo as recorded on a tape recorder- rs 1\ a meaningless jumble -to check the synchronising. - SYNCHRONOUS $YNCNRONOUS MOTOR á, MOTOR AND TUNING FORK) i . TUNING FORT( RECORDING CYLINDER $YNC.YRONIZER% 1 J { I.. .. t. , r . Fl t LAMP . 1 i ú RELAY 1 ittzicr LIGHT fSHUTTER' l CroyTo RELA1 `LENS ..nt _w` á -`A ómcAAPRIc d., `]. FILM .,,-; I 11111.7 - INK CONTAINER IL_J i s ; - /-- r i SPECIAL PEN SENSIiIVE FILM 1 ON SYNCRRON12ED - - LINE DRAWING REPRODUCTION ROLLERS RItOTOG RAPRIC REPRODUCTIOMÍ YXIENCETIND. IMYEI1f1ION Science and Invention for February, 1925 1013 POTAS- SIUM LIGHT CHAMBER COATI N G SYNCHRONOUS MOTOR N T `"' wELECTRIC T e ; r ^® l !/4 ,-, sue 'I" DIAMETER `, " PURE TUNGSTEN ELECTRODE - y", I' . '. FILLED WITH ARGON GAS 400V ` d D.C. `'- ALUMINUM DISC TO PREVENT DAMAGE TO TUBE IN HANDLING #, Y o- ', g1;cUMULATINO THE ELECTRIC EYE" - CONDENSERS "t .r , 5-\, THE TRANSMITTER CARNARVON, WALES i+- -AN 220 MILES LAND WIRE TO CARNARVOII - \- ' ^ 40 - N MODULATOR AND ,RELAV AMPLIFIER \ IHE MtD,IiU '--/ I- illlil -BATTERY - -"' 400 VOLTS D.0 The "electric eye" shown at the top is a photo -electric cell `/ Ordinarily, the current deliver whose electrical resistance varies in accordance with the t C by the "electric -eye" would be amount of light falling upon it. wl I pulsating current of varying inte sity and would ultimately result to a much inferior picture. Thus, a condenser "accumulator," another ELECTRIC LIGHT ' rLENS rE ,.' I ' development by Captain Ranger, is interposed and breaks up the SYNCHRONOUS , MOTOR ' CONDENSER 94104::' light variations into a series of *ACCUMULATOR" I Oa dots and dashes. This system of ., o modulation is found to be excel- lent, and in conjunction with the r LENS.. necessary transmitting apparatus gives a much more clearly defined reproduction. 400 volts D.C. is required for the successful opera- tion of the photo -electric cell. Note 1. transmitted photos at upper left. i' ItELECTRIC- EVE _ , .o l REVOLVING PH OTO, FILM ON ,GLASS RECEIVER TRANSMITTER TUNING FORK CONTROLLING SYNCHRONISM CYI.1f4DER `' . MARCONI HOUSE "STRAND7,- LONDON - -4»» li 1 Immediately above is shown the glass cylinder on which is placed the picture to be transmitted. Within is an incandescent lamp, the light from which is focused in a minute beam onto the film. As the light and dark portions of the picture are traversed by the light beam, the intensity of the ray is changed. This ever changing beam after having iiM_-/- passed through the film is again focused through another lens outside The receiving station where the apparatus is in absolute syn- the sensitive element of the photo -electric cell. This the cylinder onto chronism, records the photos in three ways, by device transforms the light waves into electric impulses or waves which tape. by pen sketch and photographically. Above: Complete outfit. can be transmitted by radio, much the same as a regular dot and dash message. 1014 Science and Invention for February, 1925 ISToZcQ1caGfing Wiroren aloods Some New Developments by the Army 1 L t = s;á. . ...... 1I'I . , '. ' .9 . .. ,, . . Advanced research work undertaken by the army's aviation officials shows great improvement in the trans- mission of radio messages from moving airplanes. ! I {1 , Quite recently it was demonstrated that the voice could be readily picked up by a receiving set on the ground, relayed over land line to the broadcast station from whence retransmission on a different wave -length took place. The . army has been actively engaged in making thorough tests of the possibilities of radiophone communication between airplane mail carriers and the Post Office. At the present it has been found best to employ a single wire antenna of the trailing type as it was shown that the directional effects were desirable. Our artist has depicted the cross-section of the ether surrounding the transmission ! and receiving antennas, showing the electro -static field around them. The propa- , . gation of the waves show that they enter the earth's surface and as they attenuate, go further and further, until they become too weak to be amplified. . . C Capa"Jo Illifies of Your' ReceIlvIln 01' SeI Which Do You Prefer-Distance, Volume or Clarity? CRYSTAL DETECTOR 6 days radio wire- In the pioneer of or ml ñ,i.i less, as it was then called, a recep- í. tion of a thousand or fifteen hundred - miles was conceded a record. Jii. Today, trans -continental or trans -oceanic reception is merely a matter of Whether you as the owner of a re- 7000 - tJ "pretty good. ceiving set and are proud of Its per- Z 6500-Z formance, whether you are interested 4, in knowing or not knowing about 6000 - ' TUBE/ the intricacies of the circuit it em- r 5500-" CRYSTAL -501 ploys, we are sure that the informa- 50Ó0 CLEARER tion contained graphically on this - page will prove of more than pass- X 4500 -= o' Z', TUBE 25 /o MORE ing interest to you. Radio, even at its present stage of development, < 4000 -fY ' ^ Y SENSITIVE has E still many problems to be solved. 3500 - á w O Our tubes, although 25% more sensi- tive than the still popular -v-)' . } . ) crystal, F3000 W are but 50% as clear. Our receiving a 2500 -20 o r- sets with their multiplicity of dials Z W '. J J 2000 -,, ;: Q F : and the complication therein arising O when tuning in stations, will, in the 1500 -O... - w vt W °- } : ca course of a few years, be decidedly 1000 a } ftl`" a r-` CC changed. Whether you are the own- D D ` .D a E ' Z ° . a 500 , V I- r.-1 er of a crystal set or 17 tube set, you Q should be getting results comparable 0 with this chart. RELATIVE DISTANCE. AND VOLUME SENSITIVITY'e CLARITY Science and Invention for February, 1925 1015 ll®® AnIenna Mael By FRED A. PARSONS, 2ABM Constructional Details Which Will Enable One To Build Something Useful and Distinctive HOW would you like to have a beauti- ful and artistically constructed anten- na mast, gracefully reposing in your back yard? Of course you would, if the structure didn't entail too much labor, cost, space and trouble. This substantial mast is a creation you will always be proud of, a landmark which will attract wide attention and as an observation tower really worth- while the time and trouble to build. Although provided with three mainstay guys, as a measure of safety, the tower has weathered several high gales with the guys cast off, without the semblance of a perceptible sway at the top. It is interesting to note that though entirely, made of wood, the structure is as safe as a steel structure of the same type. It has been estimated that the static load on each leg is in the neighborhood of 400 pounds, or; fifty pounds per square inch of cross-section, a fraction of the compres- sion limit of the wood used. The foundation is the most important con- sideration and no trouble was too large to overcome, in accomplishing the desired result. For each leg of the tower, a hole six feet deep, three feet long and one foot wide was dug. A large steel plate to which was securely bolted two iron rods, was first put in. One ton of large stones was then thrown in on top and finally, after hav- It' ing placed the first sections of the legs in place, three-quarters of a ton of concrcte titre cast around them. LIST OF MATERIALS LUMBER This veritable giant of colossal proportions can be seen for miles around. 2 x 4 Legs -240 feet. 2 x 3 Bracing -900 feet. 1 x 4 Flanges for Legs-150 feet. 2'x4" 1 x 2 Steps for Ladder -100 feet. 3 a 4 Mast (1 piece) -31 feet. FITTINGS 262 bolts and necessary washers. 82 galvanized brackets. 3 special angles, A" a 2" x 2"-for guy wires. 300 feet 'Is" galvanized steel guy wire. 200 feet 4" galvanized steel guy wire. 31' /3 52 galvanized guy wire clips. 12 large porcelain strain insulators. 3 %" galvanized turnbuckles. 3 3t" galvanized turnbuckles. TMAST FOUNDATION 14 tons of concrete. 3 tons of stone. 3 steel plates, 1' a 3' x 1". _ 6'S' FROM -.17 , EARTH- 1II r '- ' :16 rx, «I*`111110( , LI STEEL PLATE 3'X I Y I" Looking upward before taking the dare to climb up to lofty heights. The first horizontal brace is placed at a height of seven feet, and the rest The ladder is perfectly safe, the rungs being sunk flush with the graduate down so that at the top, the uppermost two are but four feet apart. ladder legs and held to the structure by bolts fastened securely at The three main guy wires are attached at a height of sixty-five feet. The frequent intervals. Note carefully the diagonal and horizontal antenna mast is also guyed by three out -riggers, each five feet long and bolted bracing, each piece being rigidly bolted to the main framework so as shown in the sketch. Two king Dins allow the lowering of the topmast for as 'to insure against longitudinal and lateral play. antenna repairs. The legs are 12 feet apart at the foundation. 1016 Science and Invention for February, 1925 A L®w Loss ó wcz owl ReceIlver Refinements Which Bring in the "DX" By FRANK FRIMERMAN, 2FZ J r. HE ideal three tube broadcast re- 0 T ceiver should be easy to con- struct, should contain a minimum of appa- r ratus, and should incorporate only materials of well known manufacture. Above all, its cost cl should be low, its operation should be simple ; .. and its prowess something to boast about. Now eMM that the low loss idea has been brought to the fore-and indeed it is a step in the right direc- tion-the very latest and endorsed principles of radio engineering have been made inherent in the construction of this broadcast master- piece. With What is idea? but one tuning control operating this low loss Why have the majority of radio fans been so intensely interested on a vernier dial, the set is truly an lately in carrying out the low loss idea? The employment of low loss parts stipulates that all achievement worth while duplicating. tuning inductances shall have a minimum of losses due to distributed capacity, insulation leakage and stray capacity effects. Nor are condensers, sockets, jacks and transformers immune from \1 the primary consideration of perfect insulation, perfect contacts, and accurate mechanical and electrical design which has greatly enhanced the progress of radio during the last few years. r,f 1,1 111 ,p, _ -J t,IIHU1rl 4 I1,.11111111 I lii)Í ->`x (. lti 11,Jr / /1!/ IL e _r I The most important parts are the tuning induct- ance and variable condenser. Of these, the con- denser must be purchased. However, the induct- ance can readily be made by the enthusiastic fan with little trouble. One method of winding the List of Parts coil is by first driving an odd number of nails-in this case a wooden fifteen-into block about six 1 Bakelite panel, 7"x24". inches square. The diameter is of the coil 4[/" 1 Sub panel 10"x6". and when 30 12 completed contains turns of No. I 23 -plate low loss condenser. D. C. C. wire. The winding consists of leading 3 6 -ohm rheostats. or interlacing the wire between alternate nails on 3 Good sockets. the form, remembering wind to the wire tightly. 2 4 to 1 audio transformers. When the coil is finished, a piece of ordinary string 2 Double circuit jacks. is entwined between the windings, so as to hold 1 Single circuit jack. them together-in other words, making the coil I Filament switch. self-supporting. 12 The primary consists of turns 1 .00025 grid condenser. of No. 16 D. C. C. wound on a bakelite tube 3 I .001 by-pass condenser. inches in diameter and 2 inches long. Upon a lb. No. 16 D. C. C. wire. similar tube, 16 turns of No. 22 D. C. C. is wound, lb. No. 22 D. C. C. wire. comprising tickler. the The secondary winding 1 lb. No. 12 D. C. C. wire. may be supported by two thin strips of bakelite, 1 Grid leak, % to 3 megohms. fastencd to the panel in the conventional manner. 6 Binding posts. 2 Bakelite tubes, 3"x2". 1 4" vernier dial. 5 2" dials. I Cabinet. ° WOODEN BLOCK 16 turns # 72 D. f.C. 0n .?"dia. .00015 } Ito'3 meg. 12t ,#16000 ,,301 #I?DCC On 3"dia. -0n 42'dia. o o +d -A +B +B 221 V. 90V. The regenerative circuit in all its glory, elevated to a higher plane -by the introduction of low loss parts, still provés-that it is the old stand-by, taking its place among the foremost receivers in the world. Seié',ice aad Invention for February, 1935 1017 ThTee Ez(trm GOOCó. CCIl20 c,uhs A Seven Tube Neutrodyne Par Excellence. By E. E. LAUFER, 2AQP NEUTRALIZING NEUTROFORME S CONDENSERS AUDIO FREQ. 2MEG. TRANS. .00025 .0025 .0025 P 1 1.0025 15 6 r0 By combining the distance getting ability of the Neutrodyne 111 The values of the resistance used in the re- with an amplifier which .will give undisturbed reproduction, it sistance coupled amplifier are as follows: becomes possible to build a set whose performance is one of R, Rt, R are each 100,000 ohm resistances joy bringing. The circuit as shown above combines while R., R. and R are each % megohm grid continued IS +0 leaks. Only three 6 -ohm rheostats are neces- two stages of tuned neutralized radio frequency amplification, +22 "B" +90 non -regenerative detector, one stage of transformer -coupled and sary, one for the R.F. amplifier tubes, another three stages of resistance -coupled audio frequency amplification. !or the detector and a third for the A.F. ampli- ' fier. A SurpepIl®r) One Tube Regeheiratt©ff. By J. B. COOK STATOR A single tube circuit which will very successfully operate a loud speaker on J( all local stations is shown in the diagram on the left. It is necessary -ROTOR to place a coil containing 60 turns of No. 22 D.C.C. wire in inductive relation to an ordinary variometer CENTER VARIABLE GRID LEAK whose stator has a center tap taken TAP / off. By varying the "B" battery potential anywhere from 22% to 90 volts, it becomes possible to bring -L_ in the stations with maximum vol- .006 ume. In fact, it is possible to re- .00025 ceive them with the "B" battery en- tirely disconnected from the' cir- Wv\y/ cuit. For best results a variable 60 TURNS OHM grid leak is necessary, as well as a 0003 20 -ohm rheostat. It will be noted * 22 ON 3" COIL that the circuit has both inductive and +1111=- capacitative feed-back, well nigh' ap- /- proaching the super -regenerative 22j TO 90V circuit and much easier to control. A dry cell tube can readily be used. A SpecIlzIl 66DX99 eIlrcuIla Combining the advantages of one By MATTHIAS THURY, 2CT stage of radio frequency amplifica- tion with a regenerative detector, and utilizing the primary of the neu- trofórmer in conjunction with a variable condenser as a wave -trap, it NEUTROFORMER is possible to build a two tube set which, although not a bug -bear for .0005 volume, will bring in the distant sta- .001 tions without fail. A standard neu- 5 T. troformer is used for the R.F. ampli- fier, while an ordinary variocoupler re- wound to conform with the speci- fications given in the diagram serves its purpose well. Besides being ab- solutely free from undesirable radiat- ing properties, the set is provided with a two contact switch which al- 15 T. lows selectivity to be obtained as well TAP AT as affording a reasonable change in 30 TH. T wave -length adjustment. Though the set has a number of controls, from the standpoint of experimental de- sign, it is really worth while-. build- ing. One 6 -ohm rheostat will be found to control the filaments of both tubes nicely. 201A tubes are to o b { be recommended. A- B- 22 IV. .+45 V. 1018 Science and Invention for February, 1925 RaccfAo Orezelie In this Department we publish questions and answers which we ftel are of interest to the novice and amateur. Letters to this Department cannot be answered free. A charge addressed of 25c. is made for all questions where a personal answer is desired. TO AERIAL PHONES NEUTRALIZING COND. 1 2 MEGOHMS ROTOR -30 TURNS ROTOR NEUTROFORM ER 30 TURNS AUDIO TRANSE. 1 TO PRI. 4 10 1 RATIO ' PRI. -±10 T. AUDIO TRANSF 4TO1 RATIO 0A OBTT.O BATT. { Cfi7ti 90V. . 6V. + + V. + NEUTRALI ZI NG ROTOR ,o 3°11 r-CONDENSER I 2 MEG. iv 4101 NEUTRO - FORMER S 40T 00025 PRI K=2*,, 11111 0003 IOT i 151 65T .0005 :006 A é CA .0O2'1 1+ u+90 V. The beginner's set is rapidly being improved by the addition of more tubes. If you want good results you should try this circuit. IMPROVEMENTS of a talking machine needle served the pur- slightly on his ápparatus and in 1907 made (329) Milton Stanley, Syracuse, New pose of a contact pin, traveling York, asks: over the sur- several photographic transmissions from face of the revolving cylinder. Thus the Paris to London. Q. 1. What is the best circuit to use in circuit was made and broken as the lines Perhaps the most rewiring my single tube regenerative set into original scheme was passed under the contact pin, while at the that developed by Edouard Belin. His a three tube receiver? receiving end, by an electro -chemical action, scheme resolved itself upon the fact of his A. 1. Instead of merely adding two stages a cylinder which was of audio frequency exactly synchronized discovery that bichromated gelatin becomes amplification, the above with the transmitter, reproduced the designs insoluble circuit employing one stage of tuned R. F., under strong light. Thus he wets directly. The discovery of the effect of a film of this gelatin and places it under the regenerative detector, one reflexed and one light on the electrical resistance straight audio frequency of selenium negative he exposes, whereupon the portions stages of amplifica- became known in 1873 and shortly after- of tion will be found to give excellent results. the gelatin exposed to light swell up wards various schemes to substitute selenium more or less in proportion to the intensity for Caselli's process were tendered. The of exposure, while the RADIO PHOTOGRAPHY most protected parts re- (330) noteworthy were those of Semlocq and main flat. This forms a sort of relief map J. H. Merwin, San Jose, Calif., Perosino in 1878. asks: After quite.a long time, of the negative and is wound on a cylinder Korn in 1904, employing Semlocq's Q. 1. Kindly give a brief resumé plan with over which a stylus traces its path. A of the several modifications, put it into use and experimentation in radio photography since microphone is attached to this stylus and by its transmitted photographs several hundred its rising and falling, the resistance of the inception of the transmission of photos miles from their by telegraphy and radio? destination. A negative of microphone is varied which in turn controls the picture was wound on a glass A. 1. With the present great in cylinder the intensity of the current passing through strides and a very narrow beam of light was used it. the transmission of photos by telegraphy and At the receiving station an oscillograph as a stylus passing through it. By reflec- has its mirror deflected in radio, and the announcente..t by Col. Green tion to proportion to the of the a single selenium cell whose resist- current received and a light beam is reflected transmission of moving pictures by ance varied according to radio over a distance the amount of light thereby to another cylinder. This cylinder of nearly a hundred passing through the negative, the input feet, it will not be surprising if in cur- has a sensitized paper on it and thus, pro- the very rent was modulated into the transmitting viding near future we will be sitting in our homes the receiving and sending stations circuit. In the receiving station the current are in exact synchronism, the and listening to what the world has to say was passed picture will besides seeing through an evacuated tube which be reproduced faithfully. The hardest part the greatest opera perform- grew brighter or darker according ances that "it has to offer. to the of the transmission of photographs lies in As pulsating incoming current. These varia- the synchronizing methods employed. early as 1856, Caselli sent various de- tions in signs light were focused onto another More recent work has been done by Jen- by telegraphy using for the transmitter cylinder covered a tin foil -covered with sensitized paper and kins, Nakken. Col. Green and others who cylinder on which the de- of course after developing. signs were drawn in reproduced the believe that the transmission of moving pic- insulating compound. original picture in its entirety. By A needle acting very much like further tures by radio will 'shortly become an ac- the stylus experimentation, Korn was able to improve complished fact. WANTED!!! RADIO ARTICLES want descriptions of new radio ideas which you have desirous of obtaining new hook-ups and WEworked out in practice. Take photographs of descriptions of single portant the im- tube sets, reflex and other types which have proven satifac- parts and make pencil or pen and ink sketches of the tory. We like hook-ups or mechanical articles on new single tube receptors. We will i details, et cetera. We are particularly pay good prices for your ideas. ,,,,,,,,,,,,,,,, ,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,, -Editor. ,,,,,,,,,,,,,,,,,11,,,,,,,,,,,,,,,,,,,,,,.,,,,,,,,,,,,,,,,,., ,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,W,141w.,,,,,,,,,,,,,,,,,,,,,,,.,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,usluntamu, u: Science and Invention for February, 1925 1019 BUZZER OSCILLATOR of low loss and careful design is employed, their reception is very limited. Again, sig- (331) John Ballinger, Fort Worth, SWITCH? Texas, says he has recently completed a nal strength seems much more intense and Neutrodyne sets and asks: the degree of clarity becomes more dis- Q. 1. I am in need of a buzzer oscil- tinct. Since tuning is so extremely sharp, lator in order to help me neutralize the set. interference is practically unknown, al- I would, therefore, appreciate it very much, though occasionally, it is possible to pick up if you give me complete details as to its a harmonic from a powerful long wave construction. transmitting station. Due to the great A. 1. The buzzer oscillator often finds chances for leakage at these high frequen- other uses than that for the purpose of cies, special care must be taken in the use aiding in neutralizing a set. It can be used of the various insulating materials to be very successfully as a wavemeter if care- employed. Large sized wife should be used in the tuning coils, No. 16 seeming to be . fully calibrated, and will afford many other uses. On a cardboard or bakelite tube, very efficient for the shorter wave. three inches in diameter and three and one - .0003 MF. 70 TURNS OF - ha] f inches long is wound 70 turns of No. VARIABLE Nº.22 D.C.C. WIRE INTER -ELECTRODE CAPACITIES 22 D.C.C. wire. Connected across this coil CONDENSER ON 3.DIA.TUBE (333) Jonas Kaufmann, Syracuse, New is a 15 plate variable condenser, having a York, asks : capacity of .0003 mf. This arrangement will Q. 1. Will you kindly tell me the fre- tune approximately from 200 to 600 meters. quency limits and the inter -electrode capaci- An ordinary dry cell buzzer is conected in ties of the 201A tube? the circuit in series with a key or switch A. 1. Due to the very nature of the ques- and the buzzer -driven oscillator is then com- tions you ask, we have referred your letter plete. As shown in the diagram, only one -ro to the Director of the Research Department connection is run to the receiving set, and G'ND of the General Electric Co., Dr. W. R. that is placed on the antenna post. If Whitney, who writes as follows : neutralization is desired on the shorter "As far as the tube itself is concerned, waves, the condenser is turned until its Buzzer oscillator for use in adjusting there is no lower frequency limit. The rotary plates are nearly all the way out and neutrodyne. tube will amplify any frequency no matter the usual method in neutralizing the set is ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? how low and the lower limit at which it followed. A good way to calibrate your can be made to oscillate depends entirely oscillator is to place its coil near the first V7111,a4 Hs III? upon the capacity, inductance and resistance neutroformer of the set while listening in. of the circuit. Tune in a local station whose wave -length PrIlZe "As regards the high frequency limit, you are assured of. Then, by slowly moving $20.00. this is determined by the capacity between the variable condenser of the oscillator un- By HUGO GERNSBACK the tube elements and the length of wire til the station has completely faded out, in the tube and outside wires connecting note the reading on the dial on the oscil- HERE is a puzzle that may well these elements. These wires, no matter how lator. Then tune in another station on a tax your ingenuity. SCIENCE short, have a certain inductance and this different wave -length and again set the os- & INVENTION offers $20.00 in combination with the capacity of the cillator until the station has completely dis- for the best solution of the puzzle. tube gives a certain natural electrical period, appeared. This puzzle will be known as the which represents the highest fundamental Thus a series of points are plotted and a "Five Sense Mystery". The subject frequency that can be obtained from the very accurate graph is consummated which under consideration is an. inanimate tube oscillating in the usual manner. In will come in very handy. As can readily thing-meaning that it is not living. the small standard Radiotron tubes avail- be seen, the device lends itself very effec- You can taste it; able at the present time, it is probable that tively to use as a wave -trap. you can smell it; this limit is somewhere in the neighborhood you can hear it; of two or three meters. Utilization of SHORT WAVES you can see it and, harmonics, however, may allow this figure (332) Charles Reiser, Asheville, N. C., you can feel it,- to be exceeded. These limitations, of course, asks: in other words you use all of apply only to the use of the tube in the Q. 1. Can you please state whether it has your five senses. Yet, and most usual forms of oscillating circuits employed been actually found that the short waves are important, you must never touch in radio work. Some interesting experi- superior to the longer ones? the particular thing. ments on very high frequency oscillations A. 1. When Marconi first placed wire- Although this may seem impos- from tubes in which the ordinary types of less transmisson on a practical basis, many sible, it not only can be readily circuits are not used have been described years ago, he propounded the theory that done, but you probably have done it in the following references. the long waves were the best and showed many times yourself. "Die kürzester, mit Vakrumrohren her- why he believed it. It has been some time The particular thing is found in stellbaren Wellen." since Marconi's first experiments and gradu- almost every household. It is H. Barkhausen & K. Kurz, ally the radio fraternity is coming to the not, for instance the wind, the Physihalische Zeitscbri ft. realization that the short waves are much ocean, etc. January, 1920-Page 1. superior to the longer ones. One reason There will be one prize of $20.00 "A Singular Case of Electron Tube Os- for this is the great proportional dif- for the best answer to the correct cillations." ference in frequency range on the shorter solution. The prize will go to the G. Breit, waves between a given number of meters. person who not only gives the cor- Journal of the Franklin Institute, Thus, between 90 and 100 meters, there is rect solution, but gives the solution March, 1924. a difference of nearly 340,000 cycles, where- in the shortest amount of space in The inter -electrode capacities of the UV - as for the same number of meters dif- the simplest language. 201A average about the following values: ference, between 400 and 410 meters, the Should two contestants submit Grid -Filament Plate -Filament Plate -Grid difference is but 18,000 cycles. It can be seen the same answer, the same prize UV -201A-6.0 mmf. 6.0 mmf. 7.5 mmf. at once that there is nearly 20 times the will go to both. This contest difference in frequency between this given closes Feb. 15, 1925. These values are not arrived at mathe- wave -length range on short waves than for Address all replies to Editor, matically. but by actual measurement. There this given range on longer waves. Thus Five Sense Mystery, c/o this Pub- is little need or reason to calculate these. the tuning is unusually sharp as we ap- lication, 53 Park Place, N. Y. C. values and they are obtained entirely by proach the lower waves and unless apparatus ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? measurement." rr ...... ,.r,r...r...... ,,...,,r.,,,..rr.,...,...r..., w...... ,,...... r,...... ,.,,..,...... ,...r.....r...... ,...... ,..., ,...... wr,.....,..,,,..,.... nuun..nnnnuun.....m.wnum 3 DeForest and Fessenden-Read Their Biographies In the October issue of Radio News, there started a biography AND INVENTION readers will read this important work by the of Dr. Lee DeForest, inventor of the Audion. This biography famous inventor. Prof. Reginald A. Fessenden's biography will run for 12 months in Radio News and we hope all SCIENCE started, in the January number. LIST OF ARTICLES TO APPEAR IN THE FEBRUARY ISSUE OF RADIO NEWS Curing Cancer with Ultra Radio Frequencies Amplifying Short Wave -Lengths with Resist- Fundamental Transmission and Reception By George Lakhovsky ance Coupled Amplifiers By Pierro Lafond By E. H. Hansen Experiments with Five Meters-Part II The Radio -Photo Letter A. Bruno By S. R. Winters Multi -Stage Radio Frequency Amplification- By William Part IV By John Scott-Taggart Regeneration and the Patent Situation The Inventions of Reginald A. Fessenden F. Inst. F.. A.M., I.E.E. By John B. Brady. Patent Lawyer ...... emu«.,.r...... ,...... ,r.,,.....,,,...., ...... ,...... r.,...r,...... r...r.,,....,...... ,... men ..... Ion...... ,..,r..,,,,.,.,...... film...... ,...... ,....,..,.,.r.r...... w,o,.....,.,...... m..rrr,..,,...... rr,,,,...,..,r...... «..,e.,...... n....u.eemm.wc 1111.,.11wwuu,wuinuuriiiwr,ii1.11111 ..... Ill ..... 11,.r1uiiiiii1,iiiwrrruurii1ir1rirr1w1...... 1111u111111irn111111w,i,1u.....1,.111111....u....I...... mmem:10...u..naer...... r.1...... hue ...... moo. elit...ln.n.,...iultum ..... u,,fen....:emu,...... otumelmeemeeni u...... noemeat ...... ne ...... : ...... 111... ilImmu e. 1020 Science and Invention for February; 1925 1 raarrl vm-a^rrrrrr. ss-lrrrrstrrrrr^r . ^l lrr rrrry pAT T "1.11llll'''''lLLL''',l''LY'r'111111'llllllllY'1111'''''1''''`,/',JL'1'''''JJ.f ^''.''./'./''r.^'1''.Y'll.`lrr./,;;/,/S Illoneyc®mb Coin M®annLIlng nniiFe Shas-penew No. 1,509,136, issued to Milton G. Goff des- cribes an improved knife sharpener as illus- No 1,510,859, issued to L. G. Patent relates to a new and interesting method of mounting honey- trated above. The sharpener is drawn along comb coils so that they may be used in a radio circuit. The illustrations above show the details of the blade of the knife several times until the the coil mountings and also how the entire unit is to be mounted on the top of a radio set cabinet. desired edge is produced. With this new type of mounting, it Is possible to turn either of the two movable coils so that they are in a different plane from the center stationary coil. A locking arrangement is also provided. Code Device Golf Access®wy WANTED pertaining to auto- ARTICLESmobiles such as handy kinks, roadside repairs and anything of interest to the man who drives a car. $50.00 in prizes every month are offered by MOTOR CAMPER AND TOURIST for such articles. Get a copy at your newsstand and see what is wanted. If your news- dealer cannot supply you send for free sample copy to: 1 MOTOR CAMPER & TOURIST 53 Park Place, New York City. 55 0/12.1=1140,1,,,,,,,,,, 1 ,111,,n ,,, 111111111111111111111111110111111/0111110010=021.1j Gas Saver WATER LEVEL. TO CONTROL No. 1,509,302, issued to N. A. Larssen. In the VALVE game of golf, it is quite necessary that in order to make the best shots, the ball be placed on a suitable mound, known as a tee. The in- vention illustrated above, is for the purpose of forming these tees. Damp sand is compressed in the base of the device and then released as shown above. A perfect tee results. No. 1,510,151, issued to L. C. Moore describes No. 1,509,929, issued to A. C. Caballero. A de- a device for introducing moist, warm air Into vice for quickly and easily making up and de- the intake manifold of a gasoline engine. This coding cryptographic messages. Circular In air is drawn from above the water level in the form, the device is readily manipulated. Cleaner radiator. gym,,, minlllll 1111011111111111M 411...01.1..li111 1101m,o No. 1,510,015, issued to C. L. Rayfield. Al- ....-10.1.----- SwuffnmrtIln ,: 1P®®& v1,;: though the device illustrated at the left appears .. to be an ordinary windshield cleaner, it differs y- therefrom in that it contains a heating unit in '. /:'';. '+^ :;` the cleaner to assist in removing snow from the windshield. . ^ mnmm nr. nmminelllll,,,l,m1mm01wn,á,1n1111u,n11nin1mmm0,mmnna.. a This new patent relates to the protection ,4- of ceramic swimming pools during ^-. the winter. A r.--,'` larger pool is formed around and above the ceramic one, the banks being of sod. In cold weather, the pool is HEATING ELEMENT filled to several feet above the ceramic walls. Ice forms on the top, but the water cannot freeze as low as the ceramic surface. This pool may be used as a skating INSULATION rink in winter as shown at the right. Science and Invention for February, 1925 1021 SeIlceinAlfi c rclum®T ,,,,,,,,,M,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,I,.,,,,,,,,,,,,,,,..,,,,,,,...,,.,,.,.,.,.,, ,,,,,,,,,,,,MW,,.,,,,,,,,,, ... HASN'T HYDROGEN HY DENSITY? THIS SUIT NEEDED NO IRONING The class in college chemistry had been FñrsC IP e laeoe CUSTOMER: "Say, this suit is rusty already studying hydrogen. In the examination the METHUSELA USED AN ARC! and I bought it last week." CLERK : "Didn't I tell you that it would question was asked, "What substance has the MRS.OLDE - lowest density that you are acquainted with?" wear like iron."-J. C. Mello. HAM : "Thank One paper read, "Water is the least dense you so much for ROASTING A FRESHMAN substance that I am acquainted with; alcohol the wonderful and ether are lighter, but I am not acquainted birthday cake, PROFESSOR : "I'm getting some rare work with these."-Harry R. Lubckc. dear, but tell me, from the new freshman." what is the idea ASSISTANT: "Rare?" HE GOT HIS PHYSIQUES FROM of the electric PROFESSOR : "Yes, not well done."- THE POLICE GAZETTE light bulb o n Charles A.' Hall. PHYSICS P R 0 - it ?" v -OR SOME RAINMAKER, PFD. FESSOR :"Can any- MR. OLDEHAM : one tell me the "It's forty can- WALL STREET principles of the dle -power, dearie."-Paul S. Powers. LAMB: "Never l,,,,,,,,,,,,,,,,,,.,.,,,,,,,,,,,,,,,,,.,,,,,,,,,,,,,,,,,,,,,,,,,,,1,111,,,,,,,,, ,,,,,, diving b e 1 I and again ! I put for what purposes money into a coal they are used?" SCIENTIFIC HUMOR mine and it caught STUDENT : "Yes AN HISTORIC DRIVE on fire. Then I - Diving Belles Extract from St. Louis "Globe Demo- tried an oil well - are mostly used to crat"-"His drive from the third tee went and it was struck get people to buy 125 years straight for the pin and dropped." by lightning." magazines a n d -W. O. Milligan. STOCK SALES- most of 'em ain't got any principles."-Noel MAN: "In that Compton. case, I have just what you need. Our company is devel- CALL FOR STATION KAT WE receive daily front one to oping an asbestos property."-J. J. O'Con- two hundred contributions to nell. LITTLE GIRL TO BROTHER : "Jimmy, what this department. Of these AND THEN HE RECOVERED IN makes that whistle in our radio set?" one or two are available. We BROTHER, looking puzzled: only THE HOSPITAL "'Dunno. I desire to publish only scientific humor Pop : heard say he put up a 'cage' antenna, and all contributions should be origi- SHE (combing hair) "Look, my hair is and mebbe a bird got caught in it."-Harry nal if possible. Do not copy jokes full of electricity." Walters. from old books or other publications HE: "Why, of course, it's connected to as they have little or no chance here. a dry cell." OR AN INTERFERENCE ELIMI- By scientific humor we mean only such MORE HOLY THAN RIGHTEOUS NATOR jokes as contain something of a scien- TEACHER: "What insect lives on the least SHE: "What invention would mostly revo- tific nature. Note our prize winners. food ?" lutionize kissing?" Write- each joke on a separate sheet BRIGHT STUDENT: "The moth; it eats HE: "An asbestos protector for mous- and sign your nacre and address to it. holes." taches."-M. W. Harp, Reporter No. 13,578. Write only on one side of sheet. We AND THE SWISS SCHWEITZER cannot return unaccepted jokes. Please CHEESE? do not enclose return postage. THIS IS RELATIVELY IMPORTANT : is an inter- All jokes published here are paid PROF. (in history class) "It in of nations that FIRST SCIENTIST (viewing monkey in at the rate of one dollar each, be- esting fact psychology for Prussians commit suicide, they al- cage) : "It is apparent to me-" side the first prize of three dollars when the SECOND SCIENTIST: "Ah! Really, I did for the best jokes -submitted each ways use prussic acid." not know volt claimed so close a relation- that two people INQUISITIVE FRESH.: "And then, do the month. In the event green Daansen. ship."-Prospero Astreila. send in the same joke so as to tie French use Paris ?"-A. for the prize, then the suns of three POWERS WE BET THE WATER TANK dollars in cash will be paid to each one. WELL IT HAD DRAWING BURNED W hen Johnny EM.,,I,.,.,..,,,WM,,,,, 1,.,,,l,,,,,ww...U.,,MwMU,,.LI,.u,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,w was sent on er- CANADIAN: "I rands, he often ir- certainly do ad- MAKES US FEEL LIKE 30c TO ritated his mother mire Uncle Sam's PRINT THIS by lingering on prohibition o f - One day a professor was out hunting the way to watch ficers." the YANK :"Why?" when quite unexpectantly a heavy rain storm magnetic came up. He crawled into a hollow log crane lifting iron CANADIAN : - off nicely. But in the rolling "Well, I cleaned which kept the rain very the log became so water -soaked that it was mills, and one day my variable con- she was punishing denser with alco- impossible for him to squeeze out. He final- it was his fate him when his RADIO 4 hol and I couldn't ly came to the conclusion that WAVE in log, and he began to father returned from work. get any stations in to die there that think of the many mean things he had com- "What are you whipping him for?" asked U. S. A. until it evaporated." he remembered Father. H. Friedman, Reporter No. 4880. mitted, when suddenly that -Moe he had not renewed his subscription to "He's got too much iron in his blood," "SCIENCE AND INVENTION." That made him replied Mother. THAT'S THE DOPE feel so small that he was able to crawl out "What I" exclaimed the astounded man. log difficulty.-Edward M. "Yes, he just can't get away from that FRIEND : "What a horrible noise comes of the without from your radio set!" Carr, Reporter No. 10224. magnetic crane."-H. F. Richards. RADIO FAN : "Well, I guess you would make just as bad a noise if you were coming OSCILLATIONS OR OSCULA- IT HAPPENS TO ALL OF US out of the ether."-Santuel Theodore Katz. TIONS? "What ails George anyway? He looks so sad and despondent." MADGE: "How "Oh! He thought he had picked up a WOULD THE CO HEAR HER? did you miss so new station way out west somewhere-but much of the radio MR. EDITOR : "Can you tell a phone from he suddenly discovered it was only the concert after stay- a wireless set?"-J. C. Mello. phonograph in the flat above."-H. C. New - ing home last tort. night to listen in?" HOW ABOUT THE NIGHT RATE? MARJORIE: - BUT HE DIDN'T TAKE 'EM BILL: "I missed my date because of a "Charlie called "TOURIST : "To what do you attribute chemical." and there was too your great age?" WILL: "What do you mean?" much interfer- OLDEST INHABITANT: "I don't know yet, BILL: "I didn't get the nitrite."-A. Daan- ence." -J. I. there's several o' them patent medicine com- ser. O'Connell. panies bargaining with me."-Janres Wade. 1022 Science and Invention for February, 1925 v^r.r '_. Ln.j P^1.qiy'aG%yY'.iCC/Y'''J'''''''YYYLY'LLY'./'L''''./"''''''''''/'/'/'T'L'Y'L'L''''Y'`L'`. ".r'YY'.'.ry'Y'.r' Ll/'y'?/Y'.lY'`J'' The "Oracle" is for the sole benefit of all scientific students. Quest 3. Sketches, diagrams, etc., must be will be for benefit on separate sheets. Questions dons answered here the of all but only matter of suffi- addressed to this department cannot be by mail cient interest will be published. Rules under which questions will be an- answered free of charge. swered: 4. If a quick answer is desired by mail, a nominal charge of 25 cents is 1. Only three questions can be submitted to be answered. made for each question. If the questions entail considcrablé research work or 2. Only one side of sheet to be written on; matter must be typewritten intricate calculations a special rate will be charged. Correspondents will be or else written in ink, no penciled matter considered. informed as to the fee before such questions are answered. WATER FILTER well. The mixture is then allowed to stand over other type. The breastwheel has a slight ad- (1797) Roger V. Brink, San Antonio, Texas, night and the clear portion of it at the bottom vantage over the undershot wheel. The overshot asks: of the container is syphoned off and used. If a wheel is the most efficient and can stand high Q. 1. How can I purify and filter water taken few drops of amyl acetate are poured on the sur- head pressure. Whereas in tite undershot wheel, from a small face of a vessel pure it brook? containing water, will a very small portion of the buckets or vanes are . A. 1. spread By It is best first to purify and then out. using a wire bent into different in contact with the water and in the breast - filter the water. By means of precipitation with forms, the thin film can be readily picked up and wheel type, only about one-third of the wheel is potassium aluminum sulphate alum, this can be will cover the form completely, exhibiting brilliant in contact with the water, it is plainly ascertained readily accomplished. For every gallon of water, hues. If celluloid is dissolved in the acetate, the that in the overshot type practically half of the add two grains of alum, and allow the turbid film is made more durable and will last for quite wheel is constantly in use. thus giving much mixture to stand over night. The clear water is a while. greater efficiency. then decanted or siphoned off, after which it is passed into a tank containing pulverized charcoal PIPE THAWING TRANSFORMER ELECTROSCOPE and layers of sand. Here any slight traces of (1800) chemicals are removed and the water is as fresh Milton Williamson, Buffalo, New York, (1802) James F. Dickson, New Orleans, La., and clear as could be desired. desires data on a step-down transformer to be asks: operated on 110 volt, 60 cycle A. C. supply for Q. 1. Can you kindly give Inc the details con pipe thawing. A. 1. The data given herewith can be used to construct a two K. \V. transforter giving a ALUMINUM HYDROXIDE BRASS RADIOACTIVE SO TO WATER OED SUBSTANCE / umimmmmrImnmumummnnmmnimunnmmiuunnmun n, nw, ,uuuunum nnnuw KNOB PWOODINED /SEDIMENT Interesting Articles to BAKELITE - CHARCOAL Appear In February Issue of "The Experimenter" uS BRASS The Tauleigne Microphone Amplifier. BRASS .PLATES SAND\ ROD 3' DIA. - :rt:i:::.C;: c:::.. _..-. ,.i'>':Í;`,. Lessons in Elementary Glass Blowing, -BRASS By Earle R. Caley. ROD CHARCOAL PURE Listening in for the Stars, WATER By William Grunstein, E. E. GLASS JAR -LINED WITH Heating Metals Under Water, SCALE GOLD TIN FOIL LEAF By R. A. Goepfrich. The purification of water is an absolute neces- A sensitive device for sity and must be done in a thorough manner. Ball Lightning. detecting radio-active No matter how dirty, water can always be substances is an instrument known as an made fit to drink. electroscope. Its complete construction is Galvani and His Work. detailed clearly above. BIRTH STONES A 13,000 -Ampere Storage Battery. cerning the construction of a device used in (1798) Robert L. Christman, Allentown, Penna., detecting radio -activity? asks: A. 1. The electroscope as used in the study Q. 1. \Vill you kindly publish a list of the of radio -activity and ionization is a very simple stones that are generally used as tokens of esteem, instrument to construct and if properly made love and appreciation? secondary potential of ( about 12 volts and develop- will give very good results. By using an in- A. 1. The desired list is given herewith. ing approximately 150 amperes. On the lamin- strument such as described herewith. Mme. Curie Month Stone ated sheet iron core, which should measure 1714" was able to detect a particle of radium weighing January-Garnet.' long x 1814" wide and having a cross section but one -hundred millionth of the weight of a February-Amethyst, Hyacinth, Pearl. of 214" x 21/4", is wound the primary winding single red blood corpusle. It was discovered by March-Jasper, Bloodstone. consisting of 244 turns of No. 8 D.C.C. magnet Faraday that due to electrostatic induction, the April-Diamond, Sapphire. wire. Care must be taken in using sufficient reading of any electroscope could not be con- May-Emerald, Agate. Empire cloth, for complete insulation. The sec- sidered as absolute, unless it was Inclosed in a June-Cat's Eye, Turquoise, Agate. ondary winding is composed of two No. 3 wires. grounded metallic container. To alleviate this, July-Turquoise, Onyx. wound in parallel and consists of 32 turns. Ex- the container is lined with tinfoil on the inside. August-Sardonyx, Carnelian, Moonstone, Topaz. treme care should be taken in handling the output Glass is much preferred in building it, while a September-Chrysolite. of the transformer. paraffined wooden top, having a bakelite center October-Beryl, Opal. piece should be employed. A heavy brass rod, November-Topaz, Pearl. WATER WHEELS terminates at the top end in a brass ball and has December-Ruby, Bloodstone. at (1801) William Richards, Pasadena, Calif., affixed the other end a brass plate and scale. asks: A long and narrow strip of gold leaf is at- SOAP SOLUTION tached by means of a weak solution of gelatin Q. 1. Can you give some information as re- in warm water, (1799) William A. Lathrop, Chatham, N. J., says gards the efficiency of water wheels? acting as the adhesive. Since he is the gold leaf cannot be touched by the hands, experimenting with soap films and is de A. 1. There are three different methods used it is advisable sirous of obtaining a good soap in to use a knife blade or soft brush solution for mak- the operation of water wheels. the types of or other available instrument to aid in fastening it. ing these films. Ile asks: which are as follows: The undershot, the breast - Q. 1. Can you help me out? wheel and the overshot wheel. The undershot A. 1. A very good soap solution would be corn - wheel is used mostly in the development of small COMPOSITION OF THE ATMOSPHERE posed of pure castile or palm -olive soap, 1 ounce, power such as in small streams, brooks and (1803) John B. Treyor, China Pond, Carmel, distilled water 8 ounces and pure glycerine, 4 slowly moving rivers and has the lowest efficiency New York. asks: ounces. The soap should be cut into thin shav- of all. The breastwheel is employed in some Q. I. \Vill you kindly tell me the composition ings and be dissolved in distilled water. \Vhen cases where a medium head of water is avail- by volume of the various constituents of the thoroughly dissolved, add the glycerine and mix able, and where it is impractical to erect any atmosphere? em ,,,mmmmmnmm,mnm,,,m,mnnn.nmlmummmmmm,mmmmeeeimm,.,nnmm,, ...nmmn,nmmn,mmrtmommnnmnrrrmmmIMInmmmmmmmm/1n1 FREE INFORMATION F you want additional information concerning any of the subjects illustrated and described in this number of SCIENCE AND INVENTION we shall be glad to give you other data we have at our command. To make this work as easy as possible for our editors, please be brief. Write only on one side of the paper and state exactly in a few words just what it is you desire further information on. We have the original manuscripts and drawings of many of these articles in our files and can furnish much additional data in most cases. Please do not fail to send stamped and self-addressed envelope. Make all questions concise and specific. Address all inquiries of this nature to INFORMATION EDITOR e/o Science and Invention, 53 Park Place. New York City. Science and Invention for February, 1925 1023 A. 1. We are giving you the desired informa- Eggs can be tested in various ways, one of of the earth was known before the time of New- tion below. which is the salt water test. If perfectly fresh, ton, but he showed that the law of gravitation is .Nitrogen, 78.03%; Oxygen, 20.99%; Argon, the egg will sink to the bottom. If it remains universal and is the force that holds the heavenly 0.94%; Carbon Dioxide, 0.03%; Hydrogen, immersed in the liquid, it is thought to be about bodies in their orbits. It is the tendency of 0.01%; Neon, 0.0012%; Helium, 0.0004%. three days old and if it rises to the surface and every body to travel in a straight line if undis- of floats, it is safe to say that it is at least a week turbed by outside forces. The gravitational attrac- Besides these, there arc the various oxides is force keeps nitrogen, ozone, water vapor, dust, sulphur fumes, old. However, preserved eggs cannot be gauged tion of the sun the that the planets by these means since it is useful only for eggs from going off at a tangent to their orbits. etc. "The planets probably rotate on their axes be- Q. 2. is the weight of air? that have been kept in the air. The best test What a process which cause they received the rotational impulse at the A. 2. The weight of air is taken as 0.001293 for examining eggs is candling, consists of placing the egg between a source of time of their origin from the original solar mass. grams per cubic centimeter. bright light and the eye. \Vhen fresh, the egg The earth, Mars, Jupiter and Saturn rotate on will show a uniform rose colored tint without then axis from west to east, the direction of their THE EGG any dark spots whatsoever. To make sure that revolution around the sun. There is some uncer- (1804) Rupert Tucker, Jersey City, N. 5., an egg is fresh, it is advisable to break it open tainty as to the direction of rotation of the other desires information concerning the structure of and examine the contents as to its odor and plaints because their surfaces cannot be seen delectable hen fruit taste. In cooking eggs, they should be placed in well enough to determine the direction in which A. 1. With the daily enormous consumption water about 175°F. in which they should be al- they rotate. Nearby bodies of large mass would of eggs through the entire world, it is truly re - lowed to remain for ten minutes. As a result, the have a very great effect on the direction of yolk will be found to be more coagulated than rotation of any member of the solar system. The the white-the egg 'albumin beginning to coagulate moon, for example, always keeps the saute face at 134° F. and requiring some time to heat the turned toward the earth. This peculiarity of ro- egg throughout. Thus it is not best to actually tation is probably due to the manner of its boil eggs. origin and nearness to the earth. We cannot say why Jupiter should rotate so much more rapidly than the earth because we do not yet know how AERIAL NAVIGATION INSTRUMENTS the planets originated. That is one of the prob- (1805) William J. Crane, Seattle, Wash., lems the astronomers are still puzzling over. desires: "Jupiter and Saturn may, in a way, be consid- Q. 1. Kindly publish a list of the essential ered to be semi -suns. Their densities do not differ instruments and indicators used on airplanes and greatly from that of the sun. They do not shine dirigibles and other aerial navigating ships. by their own light, however, and they give forth A. 1. The most essential instruments for navi- little if any heat. They are doubtless largely in gation in the air are, the compass which indi- a gaseous state. Jupiter may be partly in a cates the direction in which the air craft is molten state. Beyond a doubt, both of these pointing; the air speed indicator, giving the bodies are surrounded by dense vapors. Their interiors may be very hot even if little or any heat escapes to outer space. The density of Saturn is less than that of water so it must be IMPORTANT chiefly gacsous. Certainly neither of these bodies have solid surface crusts. There are certain defi- TO NEWSSTAND READERS nite facts known about these planets such as size, j N order to eliminate all waste and un- mass, density, rotational periods, presence of + sold copies it has become necessary to dense atmosphere, etc., but there are other facts supply newsstand dealers only with the ac- that are not so well known and we can only spec- What art egg looks like when viewed section- tual number of copies for which they have ulate about these at present." ally. "A" is the shell; "B,' double membrane orders. This makes it advisable to place of shell; "C," the air chamber; "D," the outer an order with your newsdealer, asking him RELATIVITY or fluid albuminous layer; "E," thick, middle to reserve a copy for you every month. Otherwise he will not be able to supply (1807) Charles C. Johnson, St. Louis, Mo., albuminous layer; "F," inner albuminous lay- your wants to know: of "HH," copy. For your convenience, we are er; "G," membrane the Chalaza; appending herewith a blank which we ask Q. 1. Is it true that the upper portion of a the Chalaza; "I," Vitelline Membrane; "J," you to be good enough to fill in and hand wheel travels faster than that part in contact Germ; "K," Yolk; "L," Latebra. (After to your newsdealer. He will then be in a wih the ground? Mace.) position to supply copies to you regularly A. 1. While it is true that the upper portion every month. If you are interested in a wheel has less resistance than the lower part receiving your copy every month, do not in contact with the ground, due to the fact that markable that we are able to have them strictly fail to sign this blank. It costs you noth- there is such little compression in the members fresh on our table. Eggs contain a relatively ing to do so. of the wheel and also that each point on the large portion of proteids, and also mineral matter periphery of said wheel is fixed in relation with which latter goes to furnish the salts of the bones, any other point and with the center, it remains especially calcium phosphate. The egg is one of clearly evident that one part cannot go faster, the most concentrated forms of nutriment in that To._..._.._._...... _...._...._...... _...._... Newsdealer actually, than any other. Proteids serve as a fuel it furnishes also fat. Address _....._.._ Let us refer to the diagram. We have here a for the body and also provide nitrogen which is wheel with center C. Suppose we move said in very much needed for growing children and the Please reserve wheel Vs of a turn and we will have as a result in repair. for me ...... _.....copies of case of old people to keep the body SCIENCE & INVENTION every month the wheel with its center now at H. B will have So-called egg substitutes have been placed on the until I notify you otherwise, and greatly traversed the distance BG, while A, the distance market, but strange to say, although claims were oblige, AE; and D the distance DF. With relation to presented that they contained all the ingredients of the earth, B will have moved the distance BK. eggs, most of them fell far short. They are Name ..._.._....._ Note the relative values of the distances BJ composed of other forms of protein matter, and BK that simply denote the relative speeds usually casein from milk, colored to resemble the Address _ _ _ ...._ of both the lower and upper portions of the "1 ' r "u,,.,.,.ui 1"11 egg in tint. Roughly speaking, the egg contains .1,,, ...... , ," ...... ,,", '1,., ,'111,,,,,,.,...i 1,°.... "1' ..... ,°.1 ,,,,,i1u ,,., 1" " , " ""I, ', wheel. However, both the actual linear and about 70 per cent. of water, 12 per cent. albumin angular velocities remain the same for A and B. and 12 per cent. fat. What is known as the white Thus you can see that relatively, with relation from the speed of the airship relative to the air; the of the egg, or albumin, when separated altimeter, indicating height. Then there is a to a fixed point on the earth, there is quite a yolk, membrane and shell, is a colorless, glary multiplicity of other instruments which give large difference in the speed of different points fluid, soluble in water. When the white of an certain other necessary data and are known as on the periphery of the wheel, but actually each egg is put into boiling water, it undergoes a follows: The turn indicator, to assist in flying point has the same angular and linear velocity remarkable change and enters a state of coagula- through clouds; the aero-bearing plate, for fixing with respect to the center of rotation. tion. In this state it is insoluble in water and position and determining ground speed and drift We assume a wheel to carry a vehicle. The opaque, forming a solid mass which however (from which the wind velocity may be determ- velocity of its center will be equal to that of of water. It is still contains a large proportion ined) ; a course -setting instrument by which the the vehicle. The tangental velocity of its high probable that during coagulation, chemical as well operation of course -setting, radius of action, in- as physical changes may have occurred. It is terception, correction of wrong course or calcu- to this extent that the white of an egg is ex- lation of wind may be carried out. Precision tremely unstable and of a complex nature, its thermometers, barometers, and hygrometers are fixed properties being so indefinite that it is hard also carried. In addition, a sextant is sometimes to say whether it is a definite chemical com- carried, but it is only effective for taking bear- pound. The egg albumin may be taken as the ings to celestial bodies during an ocean pas- representative of a group of substances classified sage or at night. together as proteids or albuminoids. It contains five elements, namely, carbon, hydrogen, oxygen, nitrogen and sulphur. The last named element is ASTRONOMY the cause of the odor of decaying eggs. (1806) Loren Lorensen, Brooklyn, New York, The yolk of the egg is composed of albumin, wants to know: fat and phosphorous bearing material known a. Q. 1. What is the force which holds the lecithin. It is a well known fact that the yolk planets in their orbits? I understand that the sun of an egg is a much richer food than the white has something to do with it, but do not under- and contains in addition to the nitrogenous ele- stand what force counterbalances this attraction. ment the fat and mineral bodies necessary to nu- What causes the planets to rotate on their axis, trition. Due to the porous nature of the shell, also why is it that the planets such as Jupiter the contents within gradually grow less by evap- and Saturn rotate on their axis many times faster oration and the egg loses weight. Again, air than our earth? Kindly explain in full detail. passes through the shell pores, carrying with it A. 1. We have referred your letter to Mrs. various microbes, thus resulting in ultimate de- Isabel M. Lewis, M. A., of the United States composition and spoiling the egg. On the surface Naval Observatory at Washington, D. C., who of the shell, however, there is a thin coat of writes as follows: mucilaginous matter which is easily washed off. "You ask what is the force which holds the Does the top of a wheel really go faster than As this coating tends to keep the pores closed, planets in their orbits and what force counter- the bottom? Relatively, yes, but virtually it it is best for obvious reasons that eggs should balances it. It is the gravitational attraction of is foolish to conceive of such as an actuality. not be washed. the sun that holds the planets in their orbits. Note the diagram carefully. Preservation of the egg can be accomplished Every particle of matter in the universe attracts by artificially coating with a thin coat of var- every other particle with a force that is directly nish, thus rendering it impervious to moisture proportional to the product of their masses and est part will be twice the velocity of the center, and air. Water glass or sodium silicate is used inversely proportional to the square of their while the part touching the ground will be sta- to a great extent. However, when boiling eggs distance apart. This is the universal law of gravi- tionary, but this relation only persists for an in- so treated. there is the disadvantage of having tation discovered by Sir Isaac Newton. The law finitely small space of time. The question is them break very easily. of gravitation for falling bodies at the surface ofren propounded as a sort of catch. 1024 Science and Invention for February, 1925 AwzrrC5 In $11000 McnIkully ConIes1 The Regular Departments Pay Prizes of Their Own, Authors on Contract Receive Their Own Rates; this, With Other Special Payments Makes the Total Paid for Articles in Excess of $1500.00 Monthly. FIRST PRIZE $100.00 Stereoscopic Movies, by O. A. Owen 996 Trick Sub -Sea Photography, by Edwin Schallert 980-981 Some Unsolved Riddles of Science, by O. Ivan Lee 996 Soap Doll Actor, by Latimer J. Wilson 1002 SECOND PRIZE $75.00 TEN PRIZES OF $15.00 EACH Social Life of the Ant, by Dr. Ernest Bade 982-983 Fireworks Photo, by J. M. Howard 996 TWO PRIZES OF $50.00 EACH An Emergency Foot Bridge, by P. C. v. Petegeln 1006 Small Microscope from Glass Beads, by Ed. Kuvvatch, Jr 1006 Find the Hair-Find the Criminal! by Mel Wharton 984 Time Glass, by F. R. Newton 1007 How to Build an Auto Speedster, by A. Luers 1004 George Magnetic Snake, by S. Leonard Bastin 1007 Egg Trick, by C. L. Walter THREE PRIZES OF $35.00 EACH 1007 Novel Experiments with Heat, by Earle R. Caley 1008 Poison Gas Shells, by Lieut. Robert E. Sadtler, U. S. Army.. 989 Hookup, by E. E. Laufer , 1017 How \Ve Digest Foods, by Ismar Ginsberg 1000 Hookup, by J. B. Cook 1017 One Hundred Foot Aerial Tower, by Fred A. Parsons 1015 Hookup, by Mathias Thury 1017 FIVE PRIZES OF $25.00 EACH FIFTEEN PRIZES OF $10.00 EACH Shooting the Air to Test Wind, by Ernest Brennecke 976 For Walkers (author send address) 1003 Automatic Railroad Crossing Gate, by J. W. Von Stein 977 Hammer Kink, by Florence E. Moore 1007 Phosphorescence, by Raymond B. Wailes 997 Printing Mask, by A. P. D'Ambra 1007 Stunts for Smoker, by Walter B. Gibson 999 Soldering Iron, by George A. Coates 1007 A Low -Loss Broadcast Receiver, by Frank Frimerman 1016 Paper Holder, by S. Schlesinger 1008 FIVE PRIZES OF $20.00 EACH Jar Rack, by E. M. Quimby 1008 Letter Scale (author please send address) If New York City's \Vater Supply Should Fall as Rain, by 1008 Gray 1059 C. N. Holmes 977 Poem-George Safety Razor Blade Gives 400 Shaves, by O. H. Knoon 993 (No further Entries) $13,320.00 in Prizes Paid Last Year WITH the December issue our $12,000 a year prize contest esting and to otherwise excel in the reporting of science and inven- came to a happy conclusion. Not only did we pay out tion. Small wonder then that with the enthusiastic co-operation $12,000 in prizes as announced in our November, 1923 issue, of our thousands of Reporter -Correspondents, SCIENCE & INVEN- but we did actually pay out in prizes alone, not less than $13,320.00 TION today occupies an enviable position in the scientific press. to 1,112 winners. These prizes every month ranged from the first The $12,000.00 prize arrangement has worked out so prize satisfactor- of $100.00 down to the smallest prize winner of $1.00 each. ily during the year just closed that we have decided to extend it Up to the time of going to press, SCIENCE & INVENTION had no for another year and we hope that our correspondents will be as less than 18,590 reporters scattered over every section of the globe. successful in winning prizes for the coming year as they have been These reporter -contributors have sent in an avalanche of material, during the past one. We wish to thank all of our friends for their and their efforts have been fruitful in that they have won prizes. co-operation and wish them the best of luck for the coming year. SCIENCE & INVENTION aims to print the news first, if it is inter- Note New Prize Schedule. ,,,,,,,,,,,, 7.m,,..,,,,,,,,, ,,,,, ,,,,,,, ,,,,,,,.nu,n,,.,n,,,,m1....,m,u,u,nnunm,111111.,iwum®uommumm,®mn11ununwuuw n,m.umnu:mi.m:.w. w,,,,,1.,,,,1111o .111W ,m,.u n,w,,,,wunuo111n1,,,,,,,,,1,,,,, ,,,,,, ,,,,, ewe ., Here Is How You Can Get in the Contest: $12,000 or More in Gold 82 monthly prizes will be given as $12,000 More in follows: or Gold VERY month SCIENCE AND INVEN- is IDEAS. These ideas will he handsomely $100.00 a TION pays $1,000 or more in gold in FIRST PRIZE 9 paid for. We have published a pamphlet prizes. Every text article published will .SECOND PRIZE $75.00 showing the rules of the contest which we receive a prize-(most of the departments 2 PRIZES OF $50.00 each S shall be glad to send to anyone free on re- have awards of their own which they give 3 " " 35.00 44 ceipt of a postal card with your name and every month). Ideas are what the Editors 5 " " 25.00 " address. The pamphlet gives full details, want. The ideas must be told simply, so that 5 " " 20.00 " the rules and how to submit articles. The your mother or your sister can understand 10 " " 15.00 " magazine itself shows you what is wanted. them-in pictures or sketches or both. But 15 " " 10.00 " Study it closely and submit your ideas. the idea must be new and must have some- 10 " " 5.00 " The closing date for all prize contributions thing to do with science or invention. 15 " " 2.00 is the 15th of the month preceding date of is Editors want 41 411.00 The pictures and sketches- 15 "" _ sue, i.e., the 15th of Feb. for the April issue, must have them-but what they want most ,,,,,,,,,,,,,1110111111111.101.1111011111111111,,,,, ,,,I,,,,,,,,,,,, ,,,,,,nn,,,,,,,,.n,,,,,,,,,n,.,,,,,n,,,,,.1,,,,,,,,,,, the 15th of March for the May issue, etc. WILL YOU BE OUR REPORTER? cienee and CORRESPONDENT N connection with our $12,000 prize contest announced herewith, it goes without saying that you will have to REPORTER'! do a little work in order to win a The do not wish to make it hard for you, quite the contrary. prize. Editors Invention IDENTIFICATION We want pictures and ideas and we cannot have too many of them. t.4 Herewith is reproduced our reporter's card. Up to now we have issued over 15,000. of these. Note in No. 1900(íj9 our awards how our reporters are winning prizes right along. We shall be glad to send the reporter's card free to anyone who makes an applicat'on for it. By means of this card you will be able to secure entry into industrial W THE BEARER OF THIS CAR !!_Y.-.Iri-2fGftCLf7( plants, business houses, motion picture studios, steamships, docks, public buildings, etc. This reporter's card will AN AUTHORIZED CORRESPONDENT REPORTER OP prove an open sesame to you in many instances. Every card is numbered and only one is given to a correspondent. O.15'SCIENCE and INVENTION MAGAZINE A postal card from you and a request for this reporter's card is all that is necessary to obtain one. It will be a THE Petl LISA F.RS OP SCIENCE AND INVENTION WILL sent to you by return mail. With it we will send you a pamphlet giving rules of the contest and how to proceed APPRECIATE ANY COURTESY EXTENDED THEIR in order to get photographs, to send in sketches, and other information in order to obtain a valuable prize. Not Lit REPRESENTATIVE. only will this card help you to obtain material for this magazine, but it will train you to become a news gatherer, EX .RIMENTER P LIS CO. and will he the means of helping you to earn a good deal of money during your spare hours. Address Field Editor. eCIENCE 4ND INVENTION, 53 Park Place, New York Science and Invention for February, 1925 1025 25c 13cook on Wood finfishfing t 111'5 jyj1 , ju II! al I"je -::111111E t,V ,,. AL I -t.:** 00 dfNNsO,ySO .n Lra RAfI/yshiqgv MINSPNS WoOo Dn , ~ N- i = ir- i Our book gives complete instructions for finishing all wood-hard or soft-old or new. Tells how inexpensive soft woods may be finished so they are as beautiful and artistic as hard wood. Explains just what materials to use and how to apply them. This book is the work of experts-illustrated in color-gives covering capacities- includes color charts, etc. Use coupon below for a FREE copy. ONSON'(Penetrating) 0 AYE Johnson's Wood Dye is very easy to apply. It dries Johnson's Wood Dye is a dye in every sense of the word. in four hours and will not rub off or smudge-penetrates It contains no finish whatsoever. Like most first class deeply, bringing out the beauty of the grain. Johnson's products it answers one purpose only -it dyes the wood Wood Dye is made in 17 popular shades as follows: -the finish must be applied over it. We recommend. Johnson's Varnishes or Johnson's Polishing Wax. No. 128 Light Mahogany No. 125 Mission Oak Stores displaying the Johnson Service Department No. 129 Dark Mahogany No. 130 Weathered Oak Sign carry a complete stock of Johnson's Artistic No. 127 Brown Mahogany No. 110 Bog Oak Wood Finishes and will be glad to show you finished No. 329 Red Mahogany No. 172 Flemish Oak wood panels-and answer questions on how to finish No. 120 Fumed Oak wood the proper way. No. 123 Dark Oak No. 178 Brown Flemish No. 126 Light Oak No. 131 Walnut r -----~-wl wl w -----w w-Nni No. 124 Golden Oak No. 140 Early English S. C. JOHNSON & SON, Dept. S.I: 2, RACINE, WIS. "The Wood Authorities" No. 160 Brown Oak No. 180 Gray SERVICE Finishing DEPARTMENT (Canadian Factory-Brantford) Please send me free your Instruction Book on All shades may be easily lightened, darkened or inter- Home Beautifying and Wood Finishing. I enclose mixed. Full directions on every label. Select the shade jOHNSONS 10c to cover postage and wrapping. /1 of Dye you want from the list above and order it from ARTISTIC MY DEALER IS your dealer by name and number. WOOD My Name. FINISHES Address S. C. JOHNSON & SON, Racine, Wis., U. S. A. ""The Wood Finishing Authorities" -wl--w---w-w--ww------.11City and State 1026 Science and Invention for February, 1925 niwiwnuuuun,n, u,ama,,,u ,,m,,,u.nnnnnnuauuuununniniu Eni I Doctor Hackcensawps Make BIG MONEY! Secrets IN RADIO By CLEMENT FEZANDIE We Need Men-Can You Qualify? ' 1 (Continued from page 991) Ozarka representatives make real money be- cause they give real values and deliver a real service. For instance, there is a 4 -tube Ozarka Instrument for loud speaker operation, giving instance. see wide range of reception at $39.50. Our men to a pick -pocket, for He could and Install. money man was demonstrate Ozarka Instruments at a glance how much each The Instrument makes the sale easy by Its perfor- carrying in his pocket -book, and could know mance. We train you to know radio and our methods. make you worthy to wear the Ozarka button as our which ones were worth robbing. accredited representative. Previous experience is not remained obdurate, but alas, necessary. In fact we prefer to do our own educating. The doctor If you have a clean record, are industrious, and have the locks in the office were of the most saved up a little cash. here's a real opportunity, If Choose asYour Profession you can qualify for an exclusive territory. We already primitive kind. With the aid of a button- have n47 representatives. Territory going fast. hook, Miggs was able to pick the lock of FREE, LARGE 'he closet,.and that night at ten o'clock he '`1 00, Illustrated BOOK was at the appointed trysting place, and a `ih` ELECTRICAL his 1spzP (Plan l WRITE Today for iUuatrated pair of the magic spectacles were in \ book No.101 that gives the entire pocket. Ozarks Plan. Don't fail to give the name of your county. CHAPTER III OZARKA, Inc. ENGINEERING Miss Muriel Gold was the tool of a gang 850Washington Blvd. of professional yegg-men. Poor girl ! She CHICAGO Electricity offers a brilliant future to the young was not innately wicked, but she had suc- sow man who is about to choose his career. Never be- cumbed to the wiles of a professional burg- Tube Sets A. $3950 fore has there been such wonderful opportunity in 4 this great field. Big paying positions in electrical lar, and after he had ruined her and taken work the world over are open her from her home, he had gradually forced B. S. Degree trained men-men who her to, help him and his pals in their nefari- possess specialized, practical in 3 Years knowledge. Lome to the ous schemes. The gang was well organized School of Engineering of Milwaukee-the largest and very successful, with spies everywhere and best equipped electrical school in America. to report where good hauls were to be made. Here you are trained in both theory and practice by a faculty of experts. You learn in large, finely One of these spies was in Doctor Hacken- equipped láborat ries. If you have 14 high school saw's employ. In some way this fellow had credits or equivalent, you can become an Electrical heard of the Z -ray spectacles, and the chief Engineer with a Bachelor of Science degree in 3 years. If you lack these credits they can be made of the yegg-men, on learning of the exist- up in our Institute of Electrotechnics in a short, ence of this wonderful device, resolved to intensive course. obtain a pair of the spectacles at any cost. Evidently the simpkst way was to use Muriel Practical Electrical Education Gold as a lure, and she, much as she dis- Learn by the thorough approved scientific meth- liked the task, dared not refuse. She was ods which our twenty years of specializing enable Amateur Mechanics-Model WADE wholly in the power of the gang. Hence, it BENCH -LATHE us to give you. In addition to Electrical Engineer- Makers-Students Cap: 4" dla. a 12" ing, the followirg complete courses are given: was that she had waited for Miggs at the length. Sliderest has A. C. and D. C. Armature Winding-Wiring and theatre, and hence it was that she met him travel entire length of Testing-Practical Electricity-Drafting-Electro- bed. Leadscrew Inside technics-Commercial Electrical Engineering-Auto the second time to bring him in her auto to r Sed. Hollmv spindle. Electrical Service Engineering and Automotive one of the lairs of the gang. Turning. facing. bor- t lag, drilling, wind- Electricity. Miggs did not have long to wait for her. ' ing, thread -cutting. Pitt $28 F. O. B. New York. Free Circulars. EARN. Scarcely had he stationed himself in front THE GEROLD COMPANY WHILE YOU LEARN of the theatre, when the young lady made Dept. S-6. 120 Liberty Street New York You can earn money to help defray your ex- her appearance in her auto. penses while learning. Our wonderful co-operative plan brings an Electrical Career within the reach of "Have you got the spectacles, Miggs?" she every ambitious man. Our Free Employment De- asked eagerly. partment secures positions for those students who For an answer, Miggs slapped his bulging HOME Become More Efficient wish to earn part or all of expenses. addi- their In pocket. STUDYthrough courses in Mathematica, tion, the Department will help you get a good posi- Hi ator , Engli eh, Ch em ictry, tion in the Electrical industry when your training Then jump in quickly and come to my Paycholagy, Education, Busi- is completed. Daily Broadcasting W.S.O.E. ness and 35 other subjects which the University house, and I will explain to you what I gives by mail. They command credit toward a New Term Opens February 16th wish you to do. It will be the chance of Bachelor degree and may be begun at any time. your lifetime to make your name as a de- ZiníberOitp of Chicago Big Book FREE tective." 27 Etna Bell Chlr.gn In. Mail the coupon today for our big new illustrated A half hour's ride brought the pair to a catalog. Mention the course that interests you house in an unfrequented part of the city. most and we will send you special information. lady Read about the school that trains men for practical Here the young descended, and, fol- and quick success. See how easy it is for you to lowed by Miggs, entered the house. Muriel get the training that will enable you to step to a conducted him into a parlor, and was de- Mailing Lists splendid position and a handsome income. Mail Will help you increase sales lighted with the spectacles whose operation Bend for FREE eatatoa altnne eons the coupon right NOW. No cost or obligation. and peleas on thousand. of el.esfi d Miggs carefully explained to her. eanf fear toot prospeect11Íla tem- "Now, Miggs," said the young lady, "I Gain, l'rofenwna suaineu Cowam..r.Ntional.St.teandLaeaadivtd- CJCH[SILof ENGINEERING will explain what I wish you to do. But Gurnt eed 9% 5beach..oCU-Uld of Milwaukee as I shall need you for a couple of weeks, Dept. SI -225 you'd better write a word to Doctor Hacken- U.o ÚQ St 415 Marshall Wis. saw to tell him you are called to the bedside St., Milwaukee, of a dying relative in Chicago and that you will be gone for some time. Then we shall spend Spring. Summer s2 WHY NOT Fall gathering but- : i<' SCHOOL OF ENGINEERING OF MILWAUKEE have lunch and you can start on your career terflys, Insects? I buy hundreds of kinds Dept SI -225, 415.17 Marshall Street. as a detective immediately afterwards." for collections. Some worth $1 to $7 each. Milwaukee. Wis. Simple outdoor work with my instructions, ti ! Without obligating me in any way, Please mail free Miggs cheerfully wrote the letter, and then pictures, price -list. Send 10 cents (not 72 -page Illustrated book, "Electricity and stamps) for my illustrated Prospectus be- the One Best refreshments were served. But the drink fore Mr. Way to Learn It," and particulars regarding the course I sending butterflies. Sinclair Bx.1424. Deal. 33. San have marked with an X. served to our hero was drugged, and it was Diego, Calif. ....Electrical Engineering. not long before he felt a drowsiness steal .... Eleetrotechnies. ....Commercial Electrical Engineering. over him, and was soon sound asleep. ....Automotive Electricity. was hours before he awoke again, and Protect your rights! ....Auto Electrical Service Engineering. It Inventors Recording Blank Free. ....Radio Saks and Service. when he did he found himself a prisoner in me if you have an undeveloped .... A.C. and D.C. Armature Winding. Consul t invention oer idea. Do not delay) ....Light. Motor Wiring and Testing. a small but comfortable cell, but with iron ....Practical Electricity. Rev hoisted Attorney and Engineer bars on the windows. And the magic spec- O. S. Lesza w 15 Park Row, New York, N. Y. ....I am Interested In your "Earn While You Learn" Plan. tacles had disappeared! Name Age CHAPTER IV Insure your copy reaching you each month. Sub- Address From that day on, New York city was scribe to SCIENCE & INVENTION-$2.50 a City State startled by a series of astonishing safe -rob - year. Experimenter Publishing Co., 53 Park Pl., Education (Continued on page 1028) N. Y. C. Science and Invention for February, 1925 1027 -s -- 1, - ;$1 No. 770. 45 -volt extra large ver - ti Peal. For heavy duty only. The ideal Bat- tilt "B" tery for use on !al multi -tube sets. Price $4.75. , - . ' Scientists constantly improve battery quality Es EREADY "B" Batteries today contain more The final tests showed more electricity, more bat- electricity, more service, more satisfaction than tery service, greater Eveready satisfaction with- ever before. out increasing battery sizes and with a substantial reduction in price. "B" Battery operating costs, Processes evolved by the scientists of the Union using the neu Evereadys, in most cases show a and Research Laboratories, Inc., Carbide Carbon reduction of at least one-half. when put in effect in the Eveready factories, are Battery for every responsible for this great accomplishment. There is an Eveready Radio radio use. the factories have effected At the same time Insist on Eveready "B" Batteries. a still higher standard of workmanship. A system Manufactured and guaranteed by of inspection that is a marvel of efficiency was NATIONAL CARBON COMPANY, lie. inaugurated. The results, gratifying beyond Headquarters for Radio Battery Information measure, were accomplished with a speed and New York San Francisco completeness that have few parallels in industry. Canadian National Carbon Co.. Limited, Toronto, Ontario EVEREADY HOUR EVERY TUESDAY at 9 P. M. (Eastern Standard Time) Broadcast through a chain of prominent interconnected radio stations. 1028 Science and Invention for February, 1925 ,,,,,,,,,,,,1,a,,,,1,,,,,,1,n ,,,,,,,,,nm,,,,,.,,,,,,,,,,,,,,,,,,,,,,,,,,m1,,,1,n1,,,,,,,,,,,1,,,,,,,,,,,,,a,11,1 ,,,,,,,,,. Doctor 4rCrQátS¡ys`' 100 (Continued front page 1026) Radio Hook -U s e,,,,,,,,,,aa,,,,1,,,,,,,,,,,m,1na,n,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,mm,.,nnnn,,,,,,,,,,,,,,,,,,,,,,,,11,,,, 01111.11 Erwin beries. How the burglars obtained their in- formation was a marvel, for their robberies Greer were timed to occur on the very night when Says: there happened to be important sums in the ].at tarrau.tl:Ra3 u[Paar,ee_, safes. It seemed certain that there must be collusion between the burglars and some }, 100 trusted employes, but in many cases the em- ,4, RADIO ploye had served faithfully for years. The thing was apparently inexplicable, yet the ; 'HOOKUPS .á explanation was simple. - 4 FFWEBB Muriel Gold could have thrown consider- able light on the matter, for it was usually c -'- rt4. "BE THE MAN she who visited the different banks or busi- ness houses, and by means of the magic ^ 3rd Never Out of aJob" spectacles looked through the walls of the Editor, 2.54. safes see if they contained anything worth .. to ,Revised ái . taking she also, when visiting her friends Rewrittea,, e:J° "My Special Shop Training Pre- .jj pares You for Steady Employ- in the fashionable world, looked through the -'g .etrs.ea.eV.c 10 or a Business of Your spectacles into their bureau -drawers to see if ment, there were any pearl necklaces or other jew- Own, Earning Big Money." els worth stealing. No'hiding place was se- cure against her piercing eyes, and for many Revised Edition a rich haul was the gang indebted to these 16 PAGES ADDED MEN WANTED Z -ray spectacles. The most complete; practical and up. for jobs paying Meanwhile Doctor Hackensaw had not to -date radio hook-ups book obtainable. missed the spectacles. He had received Just revised and brought up to the minute ! by 'one of the foremost radio engineers in $50 to $125 per week Miggs' note, so was not worried about the the industry. Thousands of high -pay automotive positions boy. But it so happened that the doctor was Contains only practical, efficient hook- are open for men who have the training 'neces- asked to rewrite a magazine article about ups, Crystal sets, one tube sets, reflex, sary to fill them. Hundreds of these jobs are spectacles. regenerative, radio frequency, and super offered by our Free Employment Bureau. YOU the value of these new Z -ray by setting forth circuits. I of these big money jobs. Eight He had accordingly begun can have one Gives all important details of each cir- ' weeks of training at Greer College interesting their value to the police. A detective equip- cuit so that the constructor can build will qualify you for big earnings. Then you are at once equipped for life. ped with these spectacles could spot the set he desires. revolver in a man's hip -pocket, a razor .411 Orders Within 24 Hours. GO IN BUSINESS FOR YOURSELF a Filled concealed in his boot, or a set of burglar YOU Can Obtain a Copy at All Reliable Greer training equips you to own and run Radio and News Dealers. your own garage or repair shop. You can start tools in his valise. They could look through with small capital ($25 to $50) and buy new the walls of a counterfeiter's den and see the equipment as your business grows. Thousands They could secure evidence have started this way. We will teach you how. men at work. against gambling houses in the same way, EARN WHILE YOU LEARN and could detect loaded dice or faked rou- FREE EMPLOYMENT SERVICE lette wheels at a glance. The smuggling of Prepaid Our Free Employment Bureau will help you "hootch" would be a thing of the past when get an earn -while -you -learn job and place you spectacles would . when you graduate. Only a small payment a single look through these down on selected course is necessary. Here in reveal its hiding place in an automobile or the big Greer shops you get actual work on 4, THE E. I. COMPANY coffin. Sole Distributors 6, 8 and 12 cylinder engines. Complete Greer Custom -house officials would no longer Course includes Machine Shop Practice-Shop THE CONSRAD COMPANY Management Selling Truck, Tractor a n d need to turn the contents of travelers' trunks - - 233 Fulton St. New Automobile Repairing - Lighting - Starting- topsy-turvy. A glance into the closed trunk York City Vulcanizing-Storage Batteries-D r iv in g- Z -ray spectacles would reveal everything required to make you an all-around through the automobile expert. smuggled goods without trouble. Passengers DAY AND EVENING CLASSES would be saved the indignity of a personal Outside work need not interfere with instruc- search, as the spectacles would reveal at concealed on their D in big You will forbidden goods CONS tion the Greer shops. find our once any training hours suited to your convenience. persons. Prisoners could no longer hope to "RADIO'S FOREMOST PUBLISHERS" bring concealed files or saws with them into MAIL THE COUPON their cells. for BIG FREE To physicians the spectacles would be in- BOOK, "How to Suc- Get this valuable. It would enable them to watch Mason, Fenwick.& Lawrence in the Automo- the working of every organ inside their bile and Tractor Busi- FREE BOOK patients. The slightest derangement would ness." We will also be manifest. Chemists could detect adul- Trade Mark and Patent Lawyers send Special Tuition terations in their drugs, and manufacturers offer and complete in- detect flaws in their castings. Mechanics Washington, D. C. :: New York :: Chicago formation about jobs. could perceive internal crystalizations in their machines at a glance. A chauffeur Established over 60 years. Write us. could locate his troubles without having to ,GR take his car apart. In a word the uses of References: National Confectioners' Association. Chi- 1.r+....EV.,...a . was cago; National Canners' Association, Washington. D. C.; these spectacles were manifold. There Life Savers, Inc.. Port Chester, N. Y.; Bon Anil Co. scarcely a branch of art or science which and U. S. Cigar Co., New York City; Hershey Choco- 2024 S. Wabash Ave. late Co., Hershey. Pa.; Stephen F Whitman & Son, they would not materially benefit. Philadelphia, Pa., and many others. Dept. 3303 As he wrote, the doctor bethought him he wished to locate some trouble lie had Inventions protected. Trade marks registered. CHICAGO, ILL - that with one of his new machines, so putting down his pen, he sought in his desk for the MAIL THIS COUPON Z -ray spectacles he had shown Miggs. They were gone! LO P E D ERWIN GREER. President, flashed into his mind the 2024 S. Wabash Ave.. Dept. 3303. Chicago, III. Instantly there YNelCrENC, atw-avt.,r7isvwa.mkrmeenmonsNvvcuwes Wnp Please send me FREE Book "How to Succeed In the boy's request for a loan of the spectacles. REu. mmIA-erelW Automobile and Tractor Business" and special training The inference was obvious. Miggs must o.o.eun,°r sasro°s and other ..iwwe data Send otrer. This request does not obligate me in any was. \ !n[ address wr a ,e,M you fee book FREE. have taken them without leave. VIM SOMME DEPARTO W Mew. e Y !. "I'll . .:ara[r re ow cancan,* Name "What a lad I" exclaimed the doctor. .eTu e..,u ;.. CORR Address bet he's up to some mischief !" NORWALK RADIO (Continued on page 1030) . Dept 52A 66READE ST.. NEW YORK Science and invention for February, 1925 1029 Why are Y , Starrett Tools Standard . in every Shop : -i 1 :: <..., r t tarreft Fine Precision Tools 2200 from One In something over forty years the -From the first mechanics to whom Mr. Starrett Line has increased from a L. S. Starrett sold his Improved Squares single tool, the famous Combination and Rules, the roil call of Starrett Users has grown year by year until Square, to include over 2200 differ- today every country in the world which uses machinery ent Precision Tools, Hacksaws and and precision tools knows Starrett as the Steel Tapes. Those years have seen standard of accuracy. growth a business now re- the of that What is the cause of this world-wide pre- quires the largest plant in the world ference for the Precision Tools that are devoted exclusively to the manu- made in Athol, Massachusetts? If you use facture of fine mechanical tools. Starrett Tools you know. Shown in the group at the right are the following popular Starrett Tools: Micrometer Depth Gage No. 440, Improved Finn -Joint Calipers, No. 26, Fay Spring Dividers, No. 77, Quick Reading Steel Tape, No. 5to (with Leather Case and Patented Push Button Handle Micrometer No. 224 Opener), A (with interchangeable Anvils giving range of 21 to 6'), d - Combination Square No. i i, and Thickness Gage No. 72. Write for Catalog No. 23 "LE" for description of the complete Starrett Line. le 410 7,4 47, THE L. S. STARRETT CO. - 7441 World's Greatest Toolmakers . Manufacturers of Hacksaws Unexcelled ATHOL, MASS. 1030 Science and Invention for February, 1923 = Dr. Hackensawps Make Money Taking WURIER°. Secrets PICTURES (Continued from page 1028) Couldn't Play Tremendous, big -paying opportunities aNote- 11111.11111.1111111111.11..111,111M... '.4 r aro open for ambitious men in )lod- t em Photography. This is the picture in age. Magazine and newspaper publish- Now Makes $10 00 And then sub -consciously there arose ers buy thousands of photographs each his mind the series of safe -robberies that year. Every manufacturer sends out ti 1 a high priced pictures of hia products. had taken place in the last two weeks, and --,, Every home wants portraits. Photog- the connection between the two events struck raphy is a business running into a week millions of dollar' each year. him forcibly. Got 1100 for And there Is a great shortage of "Bill Carola" Flood Pictures trained photographers. '-,\ Landaus "Some gang of burglars have got hold of "I took pictures Serenaders of a flood a n d Earn $3,000 to $10,000 a Year the spectacles!" he cried. "That explains them for sold Hundreds of men are earning the whole tiling! That explains how $100. I have they are been able to buy big money and establishing their own businesses. Even during able to tell which safes contain money. I my house and lot front the salo of spare time, while training. you must get those spectacles back at any cost. can make 17.5 a week easily- Pictures." no matter where I've! Luckily I can locate them easily. There are C. M. Cole. you v Washington. Amazing New Easy Method no other Z -rays in existence but those that 197 In 2 Days! I have produced. My special "I made $283 In I show you at home, how to do .t detector can December. Went the kind of svdrk turned out by .l locate them if they're anywhere within a out la days last the big studios In New York thousand miles of here. In five minutes week o n home and Chicago! I shots you how to v I portrait work make big money within 30 days! MC;oat. shall know exactly where they are!" and made 197." C. lit Cole bought a home with A. G. Hughes, money he had made when only It was but a moment's work to switch on Kentucky. half way through his training. the detector, and after carefully insulating So tell do I knots what I can .. do for you that I guarantee his other Z -ray spectacles, he watched the under bond to return every cent of your tuition if you indicating compass needle as it swung quiv- re not thoroughly s tlafled. ering around on tile dial. Professional View Camera FREE! "The needle points almost due North," he Write at once for Free Camera Offer . -I give you, free, n splendid pro- soliloquized, "and the strength of the Z-. rS.I fessional view camera. You will be astonished and delighted. This offer waves indicates a distance of about five open for short time only-s0 act miles. The spectacles must, at the present quick! No obligation. r ' moment, be somewhere in Van Cortland,." INTERNATIONAL STUDIOS, Inc. "Pep," he called aloud. "Do you want a Dept. 1422 Read Bill Carola's story in his own words- 3601 Michigan Ave., Chleae°. U.S.A. "When I sent for your catalog, I wanted a Tenor Banjo, chance to distinguish yourself by catching a but I hesitated a longtime as I otdn t know n note of musk. I finally decided to try It a week as you offered, and et the gang of burglars?" end of that time I found I could pick a few notes. Then 1 Pepita Perkins stopped her WEAR started the correspondence course you furnished and in type writing DON'T ',even months, even before the final payments on the Banjo with a jerk. "What!" she cried aghast. were due, 1 had taken my piece inn professional orchestra. A TRUSS Now I am making $100 a week, three times what I made as "If you want to make a little pocket a clerk. Two of my friends made money with their instru- money, Pep, there are big rewards r ments after five months practice, one in drummer and the offered BE COMFORTABLE- other a saxophonist. and neither could play ante when he for the capture of this gang of yeggmen, and Wear the Brooks Appliance, the mod- started. I wish everybody knew how easy it is-anyone who ern scientific invention which gives can whistle a tune can learn to play a musical instrument." the recovery of the stolen goods. I'll send rupture sufferers immediate relief. It Bill Carols "Spaghetti" Joe with you and two has no obnoxious springs or pads. Au- or three tomatic Air Cushions bind and draw other stout men to help him, while you can together the broken Carta. No salves or Durable. Cheap. Sent go along with plasters. Mr. Brooks another pair of my magic on trial to prove ,its worth. Beware C. E. New spectacles, and boss the whole of imitations. Look for trade -mark bearing portrait and Offer affair." signature of C. E. Brooks which appears on every Appli- Learning to Play .w The preparations took but a very few min- ance. None other genuino. Full information and booklet utes. "Spaghetti" Joe was a reformed safe sent free In plain, sealed envelope. Made Easy BROOKS APPLIANCE CO.. I72A State St.,Marshall, Mich, We now furnish breaker, whom Doctor Hackensaw liad taken with every in- FREE atrumentaFree into his employ. A full set of burglar tools The Famous KON-VER-TER Slide Rule Scholarship Certificate. This was put into an automobile, it This rule instantly adds. subtracts. scholarship entitles you to free for might be s divides, multiplies. converts frac- tuition in ono of the foremost necessary to break into a house or open a tions or decimals of an inch. correspondence schools of music Clt es sines. Co -sines, versed in the country. Whether you want safe, and Joe was the man who knew how 21tC s, sines, co -versed sines, tnncents. to learn to play for profit or only to do it. The men were also provided with n -tangents, secants, co -secants of for pleasure, this Free Scholar- angles directly. Gives square ship will make it surprisingly special gas throwers designed to throw a mots, squares. cube roots, cubes easy for you. soporific and fifth roots and pavers of all gas that would overpower the burg numbers. Logarithms, co -log- lars and render them incapable of resistance. arithms, anti -logarithms. Is In Free Trial use throughout the world. About The detector was also taken along to guide 6 inches in diameter. Is most Easy Payments them to the exact spot. complete rule of its kind ever You may have any Wurlitzer in- made to sell at a popular price. 20 pace book of instruc- strument for a week's free trial The five miles to Van Cortlandt were cov- tions and box for each rule. DeLUXE MODEL White in your own home. No obligation ered in no time, and the automobile Ivory Celluloid, $3.00 postpaid. We also handle. other to buy. Payments are arranged in soon types of slide rules, engineering handbooks and equipment small monthly sums, a few cents a brought them near a lonely house not far J. C. Bandltos. 7 Water St, Boston. Mass. Dept. B. day will pay for your instrument. from Van Cortlandt Park. Here W urlitser instruments seethe re- they de- Makes sult of 200 year's experience in scended from the machine and circled around Automobile musical instrument building. Famous for artistic quality: rich the house, and to their gratification the 27 Miles On Air tone value and fine workmanship. needle an Used in the finest bands and of the indicating compass turned so as An automobile goes 27 miles on air by using orchestras throughout the world. to point always directly toward the house. automatic device which was installed in less than S There minutes. The automobile was making 30 miles was no doubting the evidence! The on a gallon of gasoline but after this remarkable Free Book Z -ray spectacles must be somewhere invention was installed, made better than 57. The Illustrates and describes every within it known musical instrument-over that building. inventor, Mr. J. A. Stransky, 145 Eleventh Street, 8000 articles. Special offers on Pep Pukwana, South Dakota, wants agents and is will- complete outfits. Special prices therefore took her second pair of ing to send a. sample at his own risk. Write him direct to you. We also give you spectacles out of its insulated case, and our Free Trial, Easy Payment today.-Advt. plan and special Free Scholar. creeping quietly up to the house, peered ship Offer. No obligation. through the walls.. In one room she saw a ONLY Send Coupon Today dozen men smoking, drinking, and playing I/ i e a" cards-evidently the gang. In another room, .38 Special _ 1 er Co., Dept. 1252 ORDER 11 The Rudolph Wurlit Get this nesv guayan- So. Wabash Are., Chicago a beautiful young lady was lying on a N0. 117 E. 4th Si.. Cincinnati 329 couch teed blue steel, sido v. Stockton Si, San 120 W. 42nd SL New York 250 Francisco reading. This was Muriel. In still another swing cylinder 6 shot J .8'20720 Send me your Free Book on Musical Instruments, room was a boy, locked in and vainly seeking revolver. Extra fino con. Free Also 'your Free Trial Easy Payment plan and Free structlon and finish. Ac `d Scholarship offer. No obligation. some means of escape. Pep's heart gave a curate. hard hitting. 33 ',Caere] 1 r Special, and .32-20. SEND NO MONEY, ! jump as she recognized Miggs. Order now and on arrival, pay postman I Name Without a word Pep handed our special low price 114.95 plus postage. .` .- the spectacles Chicago Supply Co., 2459 Archer Av.. Chao. to "Spaghetti" Joe who had followed her. Address-_ "It's too dead easy!" cried Joe. "They're all bunched in one room and half-drunk. We City State. can get them without any trouble." To open a window and climb into the instrument was work of an instant. Pep, Joe (State instrument in which you are interested) house the Wonderful, new device, guides your hand: corrects and the three men put on their gas -masks, your writing in few days. Big improvement in three Copyr,uhl 7924, T7.. Rudolph Wurlitser Co. hours. No failures. Complete outline FREE. (Continued on page 1032) Write C. J. Cement, Dept. 44 St. Louis, Mo. r 1031 Science and Invention for February, 1925 Write today for your FREE copy of ard's New Radio Catalogue THIS advertisement is published plete sets-so simple that you your- to tell you three things everyone self can easily install them. interested in Radio should know. And it shows only tested and ap- That we believe Ward's is today proved Radio equipment-selected the greatest Radio store in the world by our Experts who are up-to-the- -that it is the real Headquarters for minute in Radio. Radio. You can just as.well'have the bene- Second, that at Ward's you can fit of our expert knowledge of Radio. buy everything in Radio without pay- Write for Ward's free 68 page Radio ing the usual "Radio Profits." Catalogue and see the low prices. Third, that this big 68 page book -a genuine reference book on Radio Our 52 Year Old Policy -is yours free for the asking. In buying Radio from Ward's you are buying from a house whose re- Our Radio Experts liability is above question. For 52 This Catalogue is a book gotten up years we have sold quality goods only. by experts. It shows all the best hook- Address our house nearest you. Dept. ups, everything in parts and com- No. 40-R Headquarters for Radio Satisfaction guaranteed or your money back. MontgorneiyWard &CQ The Oldest Mail Order House is Today the Most Progressive Chicago Kansas City St. Paul Portland, Ore. Oakland, Calif. Fort Worth 1032 Science and Invention for February, 1925 am,a,ecaaarnInmwnm,.,mnaap.n.aau..,.mnusea,.e.m,nnn,m,na,mnnmaammn D®cct®r Ilackensawps _ Secrets (Continued from page 1030) uwou=m,wn,amm,mnuu,an,m,uWmmumamum,ma,a=usa Brings You This and then placing the nozzle of the gas -throw- Genuine Underwood ing instrument into the key hole of the room Down where the villains were assembled, shot the odorless but powerful soporific gas into the Typewriter room. A minute later every member of the on 10 Days' FREE TRIAL gang was unconscious, and before they re- were strongly or A perfect machine, covered their senses they t complete in every handcuffed. One of the villains who was -, Loaleo- detail. Read all not in the room at the time, gave them a Jul e , onus about this great offer little trouble, but "Spaghetti" Joe dexter- ously tripped him up and held him while Pep adjusted the handcuffs. As for Muriel, she Radio Indujtry -'c Lind made no resistánce. .i Miggs was delighted at regaining his free- Dealers Wanted _ dom, and taking the stolen spectacles, he and 4..-,: We want dealers in - _i. every locality Pep explored the house thoroughly for the to handle our line of goods hidden booty. It was concealed in several ingenious hiding places, some in panels in the Our Proposition Means Money to You . Our prices save you money. The quality wall, others in secret recesses in chairs and of our goods insures satisfied customers. ' cupboards, but the greater portion was buried Our fast service will help you do a larke abiQe.Al4S.'i(+fim business on a small investment. under ash heap in There itlVá v li ` -- the the cellar. were watches and jewelry of all kinds, heaps Send For Our Free Catalog We supply you the finest line of mefchan of bank notes and negotiable securities. In disc-both sets and parts for building sets. all there were over five hundred thousand Our dealers' information service will help `> you quickly build up a successful profitable y.p.r - dollars worth of valuables that the thieves business. Tell us what business you are could have cashed. doing and can do. We will help you. Act quick. . No hiding place, however, was secure Yes, We Will Positively against the magic spectacles. The Z -rays W. C. Braun Co. penetrated through the walls or through the 32 So. Clinton St. Chicago, IlL Ship You floor and revealed the treasure beneath. this splendid Underwood upon receipt of only It was more work to secure the valuables $3.00. This is by far the most liberaltypewriterofer that has ever been made on so perfect a machine. than to discover them, but at last all were Nearly two million Underwood$ have been made and sold, proving conclusively that it is superior to loaded in the automobile and with the fet- PERSONAL STATIONERY all others in appearance, mechanical perfection and all-round excellence. tered burglars piled in, the car started on 200 SHEETS and Ten Days' Free Trial its homeward trip, but it was past midnight $I no We want you to see for yourself that this is the type- when Doctor Hackensaw's house was 100 ENVELOPES writer you ought to have, and, therefore, we make our great free trial offer. You merely send us the three reached. Printed with your Name and Address dollars deposit and we ship the machine for you to try for ten full days before you decide to keep it. If not The burglars all received long terms of Clear, white bond paper, with envelopes to match. satisfied, every penny of your money will be returned Your name and address printed in beautiful, rich ". to you. imprisonment, but Doctor Iackensaw would blue ink, on both paper and envelopes, and sent to Rebuilt Like New not allow Muriel to be even arrested. She you postpaid for only $1.00. (West of Mississippi Every Underwood we well is rebuilt lust like new. It le die. river and outside of U. S. $1.10.) If inconvenient anutlereg t cod 'e'nman ctu red to. ake was ah eto typewriter, w {th amel,f ,m only a tool. The kind-hearted doctor to send the money, we will ship C.O.D. Money re- iteinrwC:bspermtcáwtypeúmtiwthwo-oribbon. back speeder. vii e, o .o gave her a position in his office, and she turned if you are not more than satisfied. Order ribbon reverse. tabulator. key shift look, eta. Impossible to today. Write name and address plainly. ell it from a brand newUnderwood. ither in appearance, proved worthy of the trust he placed in her. durability or aualill of work. AGENTS MAKE BIG MONEY taking orders for A handsome reward was paid for the re- us. us today for proposition. ' Easy Monthly Payments Write our agent's One gas, monthly payment plan make. It possible for YOU to property, this eplendld mehine witnut havingto payout an bl covery of the stolen and Pep was ELITE STATIONERY COMPANY Oyfnmoney. You will hardly know you are paying for It. REméá- 6030 Mein Street Sm.thport, Pa. BhR, you hove the full we of the machine, just the same w delighted by the receipt of two thousand though it win, fully paid for. dollars in cash and a beautiful pearl neck- STUDY AT HOMEgaaI1 Over 325,000 Sold trained m sin the bilked Over 325,000 people hove purchased and been eatiefied with our lace as her share. Even Miggs received a poeltionsBla and biggest some. la product, the perfection bo amens and public life. Be by. t ourypewrritbetter rs a rid the integrity ofthiask fume? thousand dollars and a fine gold watch. dependent. Greater pprtnnl. u than r b fore. lilt But corporations a'heeded by mm Your Money Back Doctor Hackensaw thereafter kept his with fugal training. Ears Yee, you can have yourmoney back if you want It After you lays examined the typwriter carefully. used it to write letter., Z -ray spectacles locked up in one of his $5,000 to $10,000 Annually If rou decide for any reason whatever that We amideyou crap by .cep. You can train at home dar- you do not care for Degree of B. LaSalle It, you may return it to us st oar expen.e and every Denny you strongest safes. ing spare time. I.L. conferred. have paid will be cheerfully and student. practicing col in even Mate. We famish all promptly refunded. text material, including fourteen -volume Law Library. "Every great invention," said he, "is a -d. sate e.ay terms. our valuable 1N "law Guide" wad No Obligation on Your Part e book. free. send for them NOCt'ge When ºou d In the coupon for either further information power; and a power may be used either for LaSalle tGttendon Unlverdtr. Dept. 2964-L Chicago ' about our meat typewriter offer or for the type, riter locif on The World'. Largest Business Training Institution free trial plan, you are underobligationnocided whatever until good purposes or for bad ones. These magic after you have tried it and hero for yourself that ou want to keep it, spectacles are too dangerous to be put into .:_- DEAFNESS IS _ MISERY '7.--C° I know because I was Deaf and had Head Noises Write Now for Our Big the hands of the general public!" s. for over 30 years. My invisible Antiseptic Ear Typewriter Book T Drums restored my hearing and stopped Head 11 Noises, and will do for you. They are Tin? ° 11 shoat our erect big typewriter factory. lllll lllllll m,m, it ells, In this boon ,Megaphone's. be when worn. we illu.trate and describe 1 of the various prneeuee of re- Cannot teen Viet-, enameling, repiekeling and aesembllna this eplendld Under. tire when Deafness is caused by Catarrh or b wood.a in an way end It tells interesting bow each part is examined Perforated, Partially or Wholly Destroyed Natural. i d tented carefully a d thorn lily iuuuro the me j being pee yon will be t Drums. Easy to put In, easy to take out. Aral proudd to own. "'bed Reader's Forum Unseen Comforts." Inexpensive. Write for Booklet and my sworn statement of bow I roes,. Write Right Today (Continued front page 1009) Bred my hearing. Use Coupon Below A. O. LEONARD 111.1 llll,uu,D,uniwum11111uu. uuuwumlllluiumumnnllll 1111111unuunmuulluuuu17 Suite 369, 70 Sth Avenue -- Now YorI$_CIi (Not knowing to which article you refer and not MFG. Wrestling Book PREB SHIPMAN-WARD CO. knowing the context of your original communica- Tea, how to bo a great athlete d mien - tion, we cannot continent on the first portion of tific wrestler - how to WIN Staraln t* 2162 Shipman Bldg., Chicago aught m wonderful lessons by o 1t'.arÉam- your letter. Farmer n Send me your big bargain catalog and regard second statement we have strong healtth athletiandHanFndlekblg men with With to your .elf defame Be a Undo,. Yea and complete details of your surprising this to say: In all cases in awarding the pri:es bon.LeWriteffor Free Book today. Base your a... the Gold Cover Contest, the distinction al-, anoe Barns School 1252 Railway Bldt..Omaha. Nei . offer, without obligation on my part. for though apparently fine to the reader, was quite NAME definite in the opinion of the judges, one of whom OWN THE WORLD'S BEST! at least was partly responsible for the contest, STREET This worthy gentleman found that the ideas to wlicih prizes were awarded were different from binoculars, telescopes. . ° CITY STATE :sporting goods. those featured by us and there was no collusion body armor, ultra modern arms. etc. Catalog whatever.-Editor.) L free. Pacific Arms Corp., San Francisco. Calif. Science and Invention for February, 1925 1033 Om Ájou, Piaure, cVnzamzd, 02-- TROPADYNE SUPERADLO OUTFIT :i Superior to Super -Heterodyne THIS Superadio 6 Tube Set brings in Station KFKX 50 (Hastings, Nebraska), 1 2 0 0 miles, in New York City, clearly on a loud speaker, using only the small loop which comes with the outfit. The outfit advertised here is com- SEND NO plete, as listed below, everything needed is included, down to the last MONEY screw. The charts, blueprints, direc- tions and photos furnished are so complete and explicit that anyone can build this set and have it work- ing within a few hours. There is nothing additional to buy except the necessary batteries and tubes. Price TaOr'ADYMe includes mahogany cabinet and fold- ti ing loop aerial. You can pay $150 or more for an ,7' outfit, or $200 or more for a set, but you cannot possibly buy a better set than this one. No. F4477 Your Money Refunded if this set does not satisfy you in all respects-if after 5 days' fair trial you do not proclaim the TROPADYNE the best radio set you ever listened to. Note These Important Features: AND QUALITY equal to any REAR VIEW OF DISTANCE, VOLUME TONE TROPADYNE 8 tube set sold anywhere at any price. LOOP RECEPTION-Outside aerial not to be used with this set-the complete loop is included in outfit. PERMANENT LOGGING OF STATIONS Follow chart fur- nished; there are only two tuning controls and you always find the r same station at the same spots on the dials. Our log chart shows - you at what point to find any station. os MICROMETER VERNIER DIALS giving you the full advar'- tage of the exceptionally sharp tuning. OUTFIT IS ABSOLUTELY COMPLETE-Drilled panel, Ma. . hoganite Cabinet and everything else needed, except tubes and a batteries. ECONOMY and SIMPLICITY-This is not a reflex, yet six tubes do the work for which other sets require eight to ten. The Editor of the Radio News Complete List of Parts: In the August 1924 issue, said this about the Tropadyne: "Here la a remark- 2 Low 4 RICO Tropaformers; 1 Standard Variocoupler; Certified able receiver which see warmly recommend to our readers. It has several as 2 3 new and unusual features. In the first place only 6 tubes are used giving Loss 23 -plate Condensers; 1 Calibrated Transformer; Jacks; volume as the average 8 tubo Heterodyne. The selectivity of this set Is much Dials; 1 Rheostat; unusual. Uncqualities of the Intermediate transformers have now been done Fixed Condensers; 6 Bakelite Sockets; 2 Vernier each transformer. After the transformer has been and assay wins by tuning 1 Potentiometer; 1 7x24 Panel; 1 7x24 Mahogany Cabinet tuned, it can be left this way, no further tuning being necessary. "This system makes for maximum sharpness and maximum volume. An- Baseboard; 40 ft. Bus Bar wire; 1 Folding Loop Aerial; 1 Grid of superiority of the Tropadyne circuit la that it other outstanding point Posts; Flexible Wire; 1 Bakelite practically does not radiate, thereby not Interfering with other nearby re- Leak and Mounting; Binding ceiving stations. A saving of tiro tubes as well as an Mercase of selectivity Binding Post Strip; 4 doz. Screws; Full Directions. is obtained with this new circuit." RADIO SPECIALTY COMPANY, 100 PARK PLACE, NEW YORK 8.L SEND NO MONEY Tropadyne Gets Europe! SEE OUR RADIO SPECIALTY CO., too Park Place, New York, N. Y. - "Received 2BD, Aberdeen, on November 25th. Results 2 -PACE at once one complete Tropadyne Superadlo Outfit AD Please send good, except noises. 11:30 -to 11:40 talk, from 11:40 to ON as advertised in February Radio News. I will pay postman or poor. Used PAGES expressman $60.50 upon arrival. 12:00 piano number. Piano number good, talk 1378 and Tropadyne Circuit." 1379 NAME RADIO ZIMMER, 157 James St., Newark, N. J. J. N EWS STREET or R.F.D. above has been verified by "RADIO NEWS" The CITY STATE 1 034 Science and Invention for February, 1925 U.S. 7° PAT- NTS >- .11 l l lt' ¡SEND FOR .,t,kii -THIS F RM- Edn4ed by Don't Lose Your Rights Before disclosing your invention to any- A. Pe Peck one tend for blank form "Evidence of Conception" be and to signed witnessed. In this Department we publish such matter as is of interest A sample form with printed in- to inventors and particularly to those together who are in doubt as structions will show you just how to work to certain patent phases. Regular inquiries addressed to "Patent Advice" cannot up your evidence and establish your rights be answered by mail free of charge. Such inquiries are published here for the benefit of all readers. before filing application for patent. As If the idea is thought to be of importance, we make it a rule not to divulge all details, in order to pro- registered patent attorneys we represent tect the inventor as far as it is possible to do so. hundreds of inventors all over the U. S. Should advice and Canada in the advancement of be desired by mail a nominal charge of $1.00 is made for each question. Sketches inven- and descriptions must tions. Our schedule Of fees will be found be clear and explicit. Only one side of sheet should be written on. reasonable. The form "Evidence of Con- NOTE:-Before mailing your letter to this department, see to it that your name and address are upon ception" sample, the letter instructions relating to and envelope as well. Many letters are returned to us because either the name of the inquirer obtaining of patent and schedule of fees or his address is incorrectly given. cent upon request. Ask for them,-a post card will do. PRINTING TELEGRAPH SAFETY DEVICE (869) R. H. Twyman, Rivesville, W. Va., (872) L. Orman, states Paterson, N. J., says that that he has developed principles whereby he has thought of a way whereby an attachment grade crossings can be made to an ordinary tele- on railroads can be made safe. He asks whether graph circuit, which will cause the message to his idea is Registered Patent Attorneys In U.S. and Canada be typed in worth commercializing. letters instead of symbols. He A. 1. At the present time it is impos- 255 Ouray Bldg., Washington, D. C. asks if this device would almost be patentable and sible to place a railroad crossing safety device on "Originators of form Evidence of whether it would be of any value. Contention" A. the market, and unless you have plenty of avail- There are several devices of this type, able patented by various large electrical cash, we would not suggest that you patent and telegraph the same. You might take tip the w companies. All of matter with these are covered by very any of the railroad broad claims and we are of the opinion that it companies. ^ 1 would be practically impossible for you to obtain a patent on such a device. Furthermore, you would have to work against these large com- TIRE CARRIER AND -RIM TOOL I panies whose resources would 11, unlimited make (873) M. A. ,r I+ such a procedure impracticable. As you do not Chambers, Detroit, Mich.. sub- , mits sketches a send any details of your device, we cannot com- and description of a cleverly de :r--- ment upon its practicability, but signed combination spare tire carrier and rim tool 'I.,:,=...-----Y - considering the for use on automobiles points mentioned above, we would not advise you which have split rims as TO THE to part of their equipment. He asks our opinion U MAN' WITH attempt to obtain a patent. on the device. ' AN IDEA A. There seems to be several points of merit in your / ., combination tire carrier and rim tool. I offer a comprehensive, ex- OBTAINING A PATENT perienced, efficient service for his prompt, legal protection and (870) Pascal P. Pratt, Buffalo, New York, ':« wants to know whether or not an individual can the development of his proposi- obtain a patent without the assistance of an at- tion. torney. He also asks what .the usual charges for Send sketch, or model and descrip- obtaining a patent are. d tion, for advice as to cost, search A. 1. Drawings and claims of an inventon through prior United States patents, should preferably be drawn up by a patent attor- etc. Preliminary advice gladly fur- ney. The individual can do this himself, however, nished without charge. but it entails an My expense greater than that which experience and familiarity with the patent attorneys charge. These drawings ano various arts, frequently enable me to claims are submitted the accurately advise to Registrar of Patents, clients as to prob- and the first Government fee of able patentability before they go to $20.00 is charged, any expense. and the serial number is given, and when the patent has been granted, a second fee of $20.00 Booklet of valuable information is and form for properly disclosing requested. your idea, free on request. Write A search through the Patent Office records to today. establish a patent claim costs approximately $10.00 and drawings made up by the RICHARD B. OWEN, Patent draftsman will cost Lawyer $7.00 per page of illustration. The price for a 164 Owen Building, Washington, D. C. I j patent varies when taken out by a at- 2276-8 Woolworth Bldg., New regular York City jt torney, and is approximately $110.00 for a patent with one sheet of drawings, provided that no interference results. This is about the lowest cost at tshich a patent -can be obtained, consider- ing all costs and charges. C. L. PARKER Ex -Member Examining Corps, U. S. Patent OMss DOUBLE HACKSAW BLADE The tire rack and tool illustrated above pos- Attorney -at -Law and sesses some novel points. Solicitor of Patents (871) E. H. Price, Charlotte, N. C., submits American and Foreign Patents secured. Searches made a design of a hacksaw blade provided with teeth to determine patentability, solidity and infringement. on both sides. He asks whether or not this idea However, the average automobilist seldom can be patented. if ¿ver Pamphlet of instructions sent upon request carries a device for splitting a rim. Usually 'one A. 1. The idea a McGILL BUILDING WASHINGTON, D. C. of hacksaw blade with teeth or two inflated spares are carried, which can. be on both sides has been patented for some time. substituted when tires are punctured. The average automobilist will take punctured tires to a garage for repair. Therefore, garages are the places where rim tools are usually found. However, there seem to be enough good points about your com- bination to warrant your conducting a search PROTECT through the patent files to determine whether YOUR IDEAS or not the device can be patented. If you find INVENTORS it can be and you are willing to invest sufficient money in the project to obtain a patent, to manu- Send for our Guide Book, HOW TO GET A PATE NT, and Evidence of In - facture the device and to advertise it extensively we believe that you could make quite a good vention Blank, sent Free on request. Tells our ter ms, methods, etc. Send thing of it, if the combination is made to sell at a comparatively low price. im model or sket ch and description of Otherwise it would be well to forget the idea as practically every your invention for instructions. No automobile is delivered to the purchaser equipped N ame with a tire carrier. To use your combination it charge for the above information. would be necessary to remove this and fasten on your device in place of it. Street If you cannot finance the project yourself, there is a slight possibility that some manufacturer City RANDOLPH & CO. of automobile accessories would be interested. We Dept. 172, WASHINGTON, D. C. would suggest a canvass of the various concerns in order to ascertain their viewpoint of_ the subject. Science and Invention for February, 1925 1035 TRADE MARKSCOPYRIGHts PROTECT YOUR IDEAS FREE ANY NEW article, machine, design or improvement thereof, or any combination of parts or improvements in any known article y which increases its efficiency or usefulness, may be patented, if it involves invention. ºerró 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. r [ i1- ry_ f, 1 ! Drafting and Specification Room of Clarence A. O'Brien, Registered Patent Lawyer, Washington, D. C. 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. NO CHARGE FOR ABOVE INFORMATION. These books free WRITE TODAY FOR FREE BOOKS, "HOW TO OBTAIN A PATENT" and "INVENTION AND INDUSTRY" and blank form "RECORD OF INVENTION." These books. will give you valuable information, and they may save you much time and effort. Send for them, NOW. 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. USE THE COUPON attached, and immediately upon its receipt I shall send you the form Record of Invention to be returned to me with drawing, description or model of your idea; promptly upon receiving your idea I shall write you as to procedure and costs. CLARENCE A. O'BRIEN REGISTERED PATENT LAWYER Member of (COURT OF APPEALS, DISTRICT OF COLUMBIA, UNITED STATES COURT OF CLAIMS; Bar of SUPREME COURT OF UNITED STATES, SUPREME COURT, DISTRICT OF COLUMBIA Practice Confined to Patents, Trade Marks and Copyrights FREE COUPON - CLARENCE A. O'BRIEN, Registered Patent Lawyer 539B Security Savings and Commercial Bank Building Directly Across Street from Patent Office WASHINGTON, D. C. Please send me your free books, "HOW TO OBTAIN A PATENT" and "INVENTION AND INDUSTRY" and blank form, "RECORD OF INVENTION," without any obligation on my part. Name Address IMPORTANT-WRITE OR PRINT NAME CLEARLY. 1036 i Science and Invention for February, 1925 Lair ; a.adIl® eIt'efledactyIl I WANT a By H. GERNSBACK (Continued front page 978) 1.1111.1111.11.111.11.1.111111111111.1111 TO KNOW The technical end of the future invention The E. I. Co., publishes 15 complete, has already been described by the writer practical 64 -page books, covering the care and operation on every part of your Radio above. In short, the new instrument is the sets, also special books on the latest re- human hand and arm projected into the dis- ceivers. They cover every important goes. tance. Such a mechanical hand at a dis- lion a radio set user may ask and are tance can feel exactly the same as if the written by radio's foremost authorities. doctor was feeling the pulse of his patient Each book size 5% by 71/2 inches, fully il- in person. Using a television screen, the lustrated, bound with handsome stiff covers doctor manipulates his controls any way he printed in colors. chooses and the receiving teledactyl will faithfully reproduce the doctor's motions at EACH the patient's bedside. SO At the receiving end we have the feeling " you want to member, -equipped with a sound collector or microphone, so that if the doctor chooses to get married,, eh ? " 'place one of the controls over the patient's "That's fine I I'm glad to hear it. But you heart he can immediately hear amplified know, Tom, just wanting to getimarried'is not .sounds of the heart -beats, the same as if he enough to justify an increase in salary. were at the patient's bedside. The writer "Don't depend on sentiment, or on any man's may mention here of favor, to bring you the salary increases you need that doctors have already' Complete List Books listened to heart -beats of a patient a so badly. Study your work-learn to know more thou- No. I. Tips for the Radio Constructor. about it thán the other men in your department- sand miles away, located on a ship on the No. 2. How to Make a Practical Radio and you won't have to come to me for an increase ocean, each heart-beat being transmitted Receiver. in salary. No. 3. Radio Questions Answered. faithfully by radio. But the future micro- No. "Why don't you take up a home study course 4. Radio Frequency Amplifeation. phone does far more than this. No. 5. Loud Talkers and How to Build Them. with the International Correspondence Schools? No, 6. How to Tune Your Radio Set It's been the making of Joe Browning and Dick Doctors have come to know more and No. 7. One Hundred Radio Hook-uos. Roberts and some of the other men around here." more that certain noises within arteries and No. 8. All About Radio Parts. muscles mean much if interpreted No. 9. History and Operations of Vacuum Employers in every line of business are begging for correctly. Tubes. men who really want get The supermicrophone of the future will, in No. 10. Thy Nettrodyne and All About It. men with ambition, to No. in the world and are willing to prove it by II. How Radio is Received. ahead a way, supplant the X-ray, because certain No. 12. How to Locate Troubles In Your Radio training themselves to do some one thing well. internal body sounds will mean certain Set. One hour a day, spent with the I. C. S. in the things to our future physicians. No. 13. Reflex Radio Receivers. quiet of your own home, will prepare you for the No. 14. The Super Heterodyne. position you want in the work you like best. The patient's teledactyl control, aside from BY Yes, it will! Put it up to us to prove it. Mark the microphone, will also have a very sensi- SOLD ALL RADIO AND and mail the coupon to -day. tive thermo-couple, by which a minute NEWS DEALERS amount of heat can be measured. Very INTERNATIONAL CORRESPONDENCE SCHOOLS often, by means of such an instrument, so- The E. I. Company Box 6193-0, Scranton, Penna. called "hot boxes" can be located, which, Without Cost or obligation on my part. please tell me Sole Distributors how I can qualify for the position or In the subject before particularly along the regions of the spine, which I have marked an X: greatly help in certain diagnoses. In other THE CONSRAD COMPANY BUSINESS TRAINING COURSES words, by 233 Business Management Salesmanship means of a teledactyl "feeler," the Fulton St., New York City l Industrial Management Advertising microphone, and thermo-couple, a good doc- Personnel Organization IJ Better Letters Traffic Management Show Card Lettering tor of the future can accurately diagnose a Business Law Stenography nod T)ptng great variety of his patients' ailments. Banking and Banking Law Business English Accountancy (Including C.P.A.) Service The reader may ask the question here. PAT, EMI .T S Nicholson Cost Accounting Railway Mall Clerk Bookkeeping Common School Subjects "How does the patient get his teledactyl Hand books on Patents, Trade Marks, etc., Private Secretary High School Subjects receiving instrument?" Again the answer Spanish O French illuetrating sent free. Our 78 years of experience, is simple. The great doctor of the future TECHNICAL AND INDUSTRIAL COURSES efficient service, and fair dealing assure Electrical Engineering Arcnitect will send his nurse to the' patient with a fullest value and protection to the ap- Cl Electric Lighting Architects' Blue Prints small portable teledactyl, and the nurse will Mechanical Engineer Contractor and Builder plicant. The Scientific American should o Mechanical Draftsman Architectural Draftsman set up the instrument in front of the patient's be read by all inventors. Machine Shop Practice Concrete Builder Railroad Positions Structural Engineer bedside. The doctor and the machine do the Gas Engine Operating Chemistry Pharmacy rest. It is far better and cheaper for the Civil Engineer Automobile Work °Surveying and Mapping Airplane Engines doctor to send his nurse and save his time MUNN & CO. Metallurgy Mining Agriculture and Poultry than to transport himself to the patient. In Steam Engineering Radio Mathematics 618 Woolworth Building, New York this way, the doctor will be able to treat Name four or five times as many patients as he 525 Scientific American Building, Washington, D. C. Street 3.6-24 414 Tower Bldg., Chicago. Ill. Address could possibly do today. And, after all, if 387 Hobart Bldg., 582 Market St., San Francisco, Cal. he is a really good doctor, he should have 222 Van Nuys Building: Los Angeles, Cal Cis" State many patients. Occupation. It should be mentioned that the teledactyl Persona residing in Canada should send this coupon to the will probably be used very wave- International Correspondence Schools Canadian, Limited, with short Montreal, Canada lengths, possibly not more than two or three meters. At this short wave -length we can ofd ae operate hundreds and thousands of radio in- eat firms to America give i nt st struments without any interference from PATENTS consistent charge,c a each other's. With the present wave -lengths service noted for results, evidenced by many well bausa Patents of extraordinary value. Book, Pantte 4na ,fre,, of three or four hundred meters this could Lacey& Lacey, 644 F 5t., Wash., D.C, Fatah, asaf, PATENTS not be accomplished without chaos. BOOKLET FREE HIGHEST REFERENCES I'RUMPTNESS ASSURED BEST RESULTS Send drawing or model for examination ANYWAY, QUARTZ IN and report as to patentability THERE'S WATSON E. COLEMAN, Patent Lawyer GLASS 644 G Street, N. W., Washington. D. C. The geology Professor of Doolittle Uni- versity was hunting specimens of rock which INVENTORS! he wanted to add to his collection of rare Our facilities to assist you in securing patents, minerals. He had tramped all over the models, capital, etc., and our complete service PATENTS moonshine hills of Kentucky in search of to inventors will interest you. Trade -Marks. Copyrights and Patent Litigation them. On top of one hill he happened to INVENTORS INTERNATIONAL INSTITUTE 11'rito for advice and instructions how to proceed, costs etc come upon an old acquaintance. 15 Park Row. hew York Hand Book with illustrations of 100 Mechanical Move- see old toppeh," said. ments sent free on request "Glawd to you he E. "I llave found ten of the rarest quartz-" ALBERT DiETERICH "You lucky dog," said his friend, "I have Insure your copy reaching you each month. Sub- Patent Lawyer end Solicitor scribe to SCIENCE & INVENTION-$2.50 a Successor to Fred G. Dleterich & Co. hunted all day and I have only been able year. Experimenter Publishing Co., 53 Park PL, 602 OURAY BLDG. WASHINGTON. D. C. to find two half pints."-N' Compton. N. Y. C. Science and Invention for February, 1925 1037 and PATENTS COPYRIGHTS OUR OFFER: FOF YOUR INNVENTION VICTOR j. F/VANS Co. " ATENT AT TORN EYS 779 , 9T!' ST., WASHINGTON, D.C. ', . ^, Fk081 'ei ° ::-:PAT.t'"=: FFI Have You an Idea? YOUR FIRST STEP before disclosing an inven- tion. The inventor should write for our blank IMPORTANT form- Do not submit your invention to anyone before "Record of Invention" you furnish proof that the invention is patentable This should be signed and witnessed and returned or application has been filed. In order to have to us together with model or sketch and descrip- Your Case Made Special to Avoid Delay You of tion the invention for instructions. No charge Should Precaution of Having Your for the above information. Take the Case Made Special in Our Office to Secure Pro- Our Four Books Mailed Free tection, Save Correspondence and Secure Early to Inventors Filing Date in Patent Office. To Secure Special How to Obtain a Patent Preparation of Your Case Send $25.00 on Ac- Our Illustrated Guide Book contains full in- count With Model, Sketch and Description. structions regarding U. S. Patents. Our Methods, OUR ORGANIZATION OFFERS Terms, and 100 Mechanical Movements illus- PERSONAL SERVICES BY trated and described, Articles on Assignment or SALE OF PATENTS, Paient Practice and Pro- EXPERIENCED PATENT SOLICITORS cedure, and Law Points for inventors. AND DRAFTSMEN. Our Trade -Mark Book THE WHOLE BEING UNDER THE GENERAL Shows the value and necessity of Trade -Mark SUPERVISION OF Protection and gives information regarding Mr. Victor Evans Trade -Marks and unfair competition in trade. J. Our Foreign Book Infringement We have Direct Agencies in all Foreign Coun- tries. We secure Foreign Patents in shortest time and and lowest cost. Interference Progress of Invention Suits Prosecuted Description of World's Most Pressing Problems by Leading Scientists and All communications and data Inventors. strictly confidential We Regard a Satisfied Client as our best advertisement; and will furnish to anyone, upon request, lists of clients in any state for whom we have secured patents. Highest References-Prompt Attention-Reasonable Terms VICTOR J. EVANS & CO. NEW YORK OFFICES PATENT ATTORNEYS PHILADELPHIA OFFICES FREE 1007 Woolworth Bldg. CHICAGO OFFICES 714-715 Liberty Bldg. PITTSBURGH OFFICES 1114 Tacoma Bldg. SAN FRANCISCO OFFICES COUPON 514 Empire Bldg. Hobart Bldg. MAIN OFFICES: 779 9th Street, N. W., WASHINGTON, D. C. Gentlemen: Please send me Free of Charge your books as described on this page. NAME ADDRESS 1038 Science and Invention for February, 7925 ..... 11..IIt111111111.1111.11111.1..111111 I..a.1111..1111,111a111..1.1 II,a,111ana,11111111111IIII..IIIIII,. ,.,I a 11,a,1.11 t 1i Rb16:110 TSTIDICIdletasir. tITtiltrr. REVISED AND CORRECTED TO DATE. First Group of Figures Indicate the Power in Watts in the Antenna of the Transmitting i1 ' .\\ - t Station. The Second Group Gives the _ .. Wave -Length. ..,.,,. 1111, 1.11,11% 1a.11:1n11111nnu,u1f111a1111111nn1.11111111. 111111n MI 1`.1111,1111 nn 1111111.... To Each \ Powall & Waveer Letters Location and Name Length Purchaser KDRA East Pittsburgh, Pa.. Westing- 9t house Electric & Mfg. Co.. 1000-326 Enter the KDPM Cleveland. Ohio, Westinghouse World Profession of Electric & Mfg. Co 500-270 Battery KDP'I San Diego, Calif, Southern A 24-Volt''B"Storage Batterypoaitivelygiven Electrical Co 50-244 FREE with each purchase of a WORLD "A" KDYL Salt Storage Battery. The WORLD Battery ie fa - Lake City, Utah, New moos for its guaranteed house Hotel quality and service. Backed 100-360 by years of Successful Manufacture and Thousands of KDYM. San Diego, Calif., Savoy The Satisfied Beers. You save 60%. 'at re 100-280 Prices That Save and Satisfy KDY11 Portland, Ore.. Oregon Insti- Auto Batteries Radio Batteries tute of Technology 50-360 6.Voit, 11 Plate $12.25 KDZB Bakersfield, 6 -Volt, 13 Plate 13.11°tt, 1oÓ Amps. 12.50 Calif., Frank E. 14.25 6 -Volt, 120 AMP.. 14.30 Through This:New Kind of Siefert 100-240 12 -Von, 7 Plate 17.00 6-Volt, 140 Amos. 16.00 KDZE Seattle, Wash., Rhodes Shipment Erma.. C. O. D. eubjeet to examination. De- 5 per sent d ueowat far ooeh is /all with order. Home Training System partment Store 100-270 KDZR Bellingham, Wash., Bellingham 2-Yr. Guarantee Bond ín Writing Publishing With Each World Storage Battery The great field of Electricity has never before needed so Co. 50-261 badly, Men who KF 1D Phoenix, Proves satlefaetory World performance. Mall this ad with Trained --then are skilled In every depart- Ariz., Mc krthur sour name end address- ire will ship battery day order Is re- ment of this fascinating Ived;sad wive you profession. The electrical industry Bros. Mercantile Co 100-360 your choice of "11.. Ft rude Batt.rrry or a Is ready and glad to pay big salaries to the men who really KFAE Pullman. band.umeelckle finish Auto Spotllte, FREE. Write TODAY. knowl Commercial Electrical Engineers, Master Electri- Wash., State College WORLD BATTERY COMPANY cians, Electrical Engineers. of Washington So. Automotive Electrical Experts, 500-330 1219 Wabash Ave. Dept. 1 o, CHICAGO. ILL. are needed everywhere, and they command handsome Incomes. KFAF Denver, We will Colo., Western Radio This FREE "B" Rtoroae Battery takes the place of dry fit you for one of these splendid places quickly Corp. batteries. and thoroughly, right in your home, while you hold yea: 500-278 boldritfor6.iitdenoatrofkToe 1Ó1 thnl, battery Its d present lob. KFAJ Boulder, Colo., equipped with solid rubber case-and In.areneo aealnnt acid University of and advantage We Colorado 100-261 (Tot nyy°f' fer It. we waillll rend FREEra KFAN Moscow, handsome nickel finish AutaSp.,tllte, instead of the "B" Bat- Unlike All Other Schools Idaho, The Electric tery. Be sure to apeclfy which le >vented./ Shop 50-360 GIVEN No other school furnishes its students with We elaborate KFAR Hollywood, Home Laboratory Units-actual working Calif., Studio size Instruments. Lighting Service FREE chemicals and electrical equipment. This gives you actual KFAU Co 100-280 To introduce practice, along with the theory, making you a skilled expert Boise, Idaho, Independent thla new d ready to take it big job. In addition, our official Broad- School rsrle casting Station WSOE District of Boise 'o0""Sto broadcasts educational lectures on City, Boise Battery to t`Ile 1.1 Electricity, richly supplementing the studies and experi- High School 150-270 Public. ments of nor home-study students. KFAW Santa Ana, Calif., The Radio Den 10-280 KFAY Medford, FREEHOME LABORATORY Ore., Virgin's Radio Service 50-283 ONE DOLLAR_ OUTFIT COMPLETE KFBB Havre, Mont., F. A. Buttrey & Co. BUYS No models, or miniature but actual size 50-360 end parts, apparatus FBC San Diego, Calif., a Moment. the same as ap work upon when out In the W. K. Azbill 5-278 TH KFBE San Luis Obispo, Calif., Reuben confuse H. Horn PHN those Laboratory KFBG Taconia, 50-242 Units with Wash., First Presby- ENNA EP LACES ee the terian Church u +5 models some- 50-360 ' times KFBK Sacramento, furnished Calif., Kimball - THE AERIAL B IIM1 by correspond- Upson Co. ence schools. KFBL 100-283 SAFER than a troublesome outdoor aerial í7B8-1 They are sent Everett, 11 ash., Leese Bros " 15-224 BETTER than an to your EFES unsightly home Trinidad, Colo.. Trinidad Gas indoor aerial l e ilhaH cost to Easy to & Electric Supply Co. Install.-The telephone is not attached you. as a part and to, but merely placed upon l7 of your The Chronicle News course. KFBU 10-280 the Antennaphone. Then con- _f3(I C n Laramie, is h Wyo., The Cathedral nect through the en- KFCB 50-283 the wire of the Antenna. Phoenix, Ariz., Nielson Radio phone thusiasm a n d Supply to the antenna post of cooperation o f Co. 10-238 your set (tube or crystal) our milled of KFCF Walla Walla, \Vasil., Frank A. and tune in. students that Moore .l we can go to .KFCL 100-360 increases Selectivity 'this enormous Los Angeles, Calif., Leslie E. and > 1 expense. Y o u Rice, Los Angeles Union Quality of Reception will get cor- Stock Yards es 7 T Ia 500-236 Our I' plate details of KFC'l' Ogden, Money Back Guarantee U", is,. t h i s amazing Utah, Ralph W. Flygare 10-360 The Antennaphone. ----,- plan when roo KFCV Iiouston, Tex., Fred will not in- write. Mahaf- tertere with the use of your !_ fey, Jr. telephone, Is I0-36CI and guaranteed to KFCY Le Mars, Iowa, Western Union work perfectly with any receiver Satisfaction Guaranteed College (tube or crystal) or your dollar 50-252 will be refunded Backed by KI-CZ Omaha, Nebr., Omaha This Great School Central The Antennaphone, complete with High School 50-258 insulated wire. 00 KFDD Price This marvelous training Is backed by the largest and best Boise, Idaho, St. Michaels Ca- , equipped electrical school In America. The thedral Telephone can he any School of 10-252 distance Engineering la endorsed and linked with some of the KFDIt Tucson, Ariz., from radio. $I largest Commercial Concerns and Power Companies in the University of country, the Arizona employers of the Big Pay Men, KFDJ 50-268 Corvallis, Ore., Oregon Agri- AT YOUR cultural College 50-360 DEALER Catalog Sent FREE. KFDL Denver, Colo., Knight Or Sent By Mail Upon -Campbell Receipt Write Music Co. of One Dollar quirk, just mailing the eoupon, for complete details KFDM Beaumont, 5-226 and catalog. It will point the sure tray to success. Tex., Magnolia Pe- Correspondence solicited from Radio troleum Co. 500-306 Jobbers and Dealers KFDX Shreveport, La., First Baptist Church THE ANTENNAPHONE CO. 100-360 90 WEST Extension Division KFDY Brookings, S. Dak., South Da- ST.. NEW YORK CITY kota State College of Agri- culture and Mechanic Arts 100-273 KFDZ Minneapolis, Minn., Harry O. Iverson 5-231 Inventions Developed soma or ENGINEERING KFEC Portland, Ore., MIR of Milwaukee Meier & If you have an undeveloped Frank Co. 50-248 invention, consult Dept. SI -11225 KFEL Denver, Colo., Winner us. We will prepare practical designs for you, Radio also Corp. procure your patent rights. 1Vrite for - KFEn Oak, 50-254 415 Marshall St. Milwaukee, Wisc. Nebr., Scroggin & Co. FREE BOOKLET. Bank 100-268 KFER Fort Dodge, Iowa. Auto Elec - Manufacturers Patent Co., Inc. SCHOOL OF ENGINEERING OF MILWAUKEE. tric Service Co 10-231 KFEX Minneapolis, Minn., Dept. SI -H225, 415 Marshall St., Milwaukee, Wise. Augsburg 10 Wall New Seminary 100-261 MI St., York Please send me your Free Catalog and details of your KFFB Boise, new home training system in Electricity. Idaho, Jenkins Furniture Co. 10-240 KFFF. Pendleton, Ore., Eastern Name Age Ore- MORE gon Radio Co. 10-360 TA M M E R KFFF Moberly, Mo., SKill the fear of stammering. Re-education the Address First Baptist key. The widely famed Hatfield Method fully Church outlined in an accurate, worth. KFFR Sparks, 50-266 while dependable. City Nev., Nevada State book --"HOW TO .STOP STAMMERING." L State Journal 10-226 bee Inapircd thousands. Free cony today. au btiTFIELG IIWSTITOTE, 109 N. Dearborn, Chicago, Ill. Science and Invention for February, 1925 1039 Power Call & Wave Letters Location and Name Length KFFV Lamoni, Iowa, Graceland Col- . ," 1 lege 100-280 KFFY Alexandria, La., Louisiana Col- LitAu Skeet_ IBRIRY Lauri lege 50-275 118RARY KFGC Baton Rouge, La., Louisiana fY twice PR>LTGll PRACTICAL ú[ l State University 100-254 9,.9Itl01T h1LTutT all haw. harm KFGD Chickasha, Okla., Oklahoma 2I.7R1(7II' College for Women (J. A. Teeters) 50-252 KFGII Stanford University, Calif , Leland Stanford Junior Uni- If these books were $25 each they would versity 500-273 KFGL Arlington, Ore., Snell & Irby 10-234 KFGQ Boone, Iowa, Crary Hardware still be a good investment for you! Co. 10-226 KFGX Orange, Tex., First Presby- terian Church 500-250 WRING \ytalNC KFGZ Berrien Springs, Mich., Em- Eight times $25 is $200. (Powu IÍMISNm manuel Missionary College. 500-286 OW& Put $200.00 in the bank at KFIIA Gunnison, Colo. Western State aórr Ca01T College of Colorado 50-252 4% interest and you get a KFHJ Santa Barbara, Calif., Fallon & little over $8 a year in- Co. 100-360. KFHL Oskaloosa, Iowa, Penn College 10-240 terest. KFHR Seattle. Wash., Star Electric Put only one -tenth of & Radio Co. 100-263 KFI Los Angeles, Calif., Earle C $200.00 into the Croft Anthony (Inc.) 500-469 books, together with a KFIF Portland, Ore., Benson Poly- little spare -time study, and technic Institute 100-360 ', back any- KFIO Spokane. Wash., North Cen- *CRAW -II,GRAW you should get tral High School 50-252 .Ra Y u where from ten to several KFIQ Yakima; Wash., First Metho- times $8. dist Church 50-242 hundred KFIU Juneau, Alaska, Alaska Elec- tric Light & Power Co 10-226 KFIX Independence, Mo.. Reorgan- ized Church of Jesus Christ of Latter Day Saints 250-268 Practical Electricity KFIZ Fond du Lac, Wis., Daily Com- monwealth & Seifert Radio By TERRELL CROFT Corp. 100-273 KFJB Marshalltown, Iowa, Marshall 8 volumes-300 pages -2,100 illustrations-flexible binding. - Electric Co. 10-248 KFJC Seattle, Wash., Seattle Post In- always been telltgencer 100-270 OPPORTUNITIES in the electrical field have KFJF Oklahoma, Okla., National Ra- abundant, but today there are more big -paying posi- dio Mfg. Co. 225-261 tions open than at any time in the history of electricity. KFJI Astoria, Ore., Liberty Theatre 10-252 New uses are being found for electricity every day, and KFJK Bristow. Okla., Delano Radio & Electric Co. 100-233 the progress of the world more and more depends upon it. KFJM Grand Forks, N. Dak., Univer- Terrell Croft is doing his share in teaching men the correct sity of North Dakota 100-280 principles of electrical practice. Ile knows the game from KFJQ Grand Forks. N. Dak., Electric Construction Co., Valley experience. He has poured out all his secrets, all the short Radio Division 5-280 cuts, all the time savers, in language that anyone can easily KFJR Stevensville, Mont. (near), grasp. Yet the text is so scientifically correct that thousands Ashley C. Dixon & Son 5-258 KFJX Cedar Falls. Iowa, Iowa State Free Examination. No money of the highest paid electrical engineers are using the books Teachers' College 50-280 down. Only 52 a month. as a reference set. KFJY Fort Dodge, Iowa, Tunwall Radio f'o. 50-246 KFJZ Fort Worth. Tex., Texas Na- tional Guard, 112th Cavalry 20-254 KFKA Greeley, Colo.. Colorado State The Sure Way to Bigger Pay Teachers College 50-273 BIG salaries are paid in the electrical field for expert knowledge. The man who knows KFKB Milford. Kans., Brinkley -Jones electricity in all its many phases-the man who has completely mastered the subject from Hospital Assn. 500-286 A to Z--can pick his own job and name his own salary. Fit yourself for a bigger position KFKQ Conway, Ark., Conway Radio by knowing electrical practice completely-inside and outside work-central stations, electric Laboratories 100-250 illumination and the whole subject. Croft will teach you. He will take you in quick, easy steps KFKV Butte, Mont.. F. F. Gray 50-283 from the simplest principles to the complete and economical operation of a great central'státi,n. KFKX Hastings. Nebr.. Wes'inghouse The Croft -trained man wins because he knows the "why" and "how" of modern 'electrical Electric & Mfg. Co. 1000-291 practice. KFKZ Colorado Springs, Colo., Nas- sour Bros. Radio Co 10-234 KFLA Butte. Mont.. Abner R. Willson 5-283 Practical Electricity Taught by an Expert KFLB Menominee, Mich., Signal Elec- tric Mfg. Co. . 50-248 No course, no set of books, offers a quicker Croft has been through the mill. His knowl- KFLE Denver. Colo., National Educa- surer method of mastering electricity than the edge has been gained by shirt -sleeve contact tional Service - 25-268 with electrical problems. He has worked his KFLQ Little Rock, Ark., Bizzell Radio Croft Library. It is founded on practice- on work as it is actually done. It is jammed way up from the bottom to the top-from Shop ' ' 20-261 from cover to cover with the kind of hard- apprentice lineman to electrical engineer for KFLR Albuquerque, N. Mex., Univer- one of the great electrical companies. Now sity of New Mexico headed, pay -raising facts you want. Written he 100-254 so the beads his own consulting company, and his KFLU San Benito, Tex., San Benito that beginner can easily understand it, name is known in every corner of the elec- Radio Corp. 15-236 yet so sound, so thorough that it is the daily trital world. He is the one man above all KFLV Rockford Ill., Swedish Evan- guide of thousands of highly paid electrical others who can show you the way to perma- gelical Mission Church 100-229 workers and engineers. - nent success. KFLW Missoula, Mont., Missoula Elec- tric Supply Co. 5-234 Easy Payments Pay for these books as you go KFLX Galveston, Tex., George R along. We have made the pay - Clough 10-240 ments so low that any man can meet them. Only $1.50 KFLZ Atlantic. Iowa, Atlantic Auto- FREE in ten days and the balance at the rate of $2 a month mobile Co. 100-273 for nine months. These are the lowest-the easiest KFMB Little Rock, Ark., Christian WITH THE LIBRARY -terms ever made on a high-grade electrical Churches of Little Rock -254 library. In addition, as soon as your first pay- KFMQ Fayetteville, Ark., University If You Subscribe Now ment of $1.50 is received, we will send you McGraw-Hill of Arkansas 100-263 a copy of Taylor's Transformer Practice Bank Co., Ins-, absolutely 370 Seventh Ave KFMR Sioux City, Iowa, Morningside free. New York JUST College 10-261 Taylor's SEND THE COUPON We want you to 'e0 OenUemen-Please test our statement: we KFMT Minneapolis, Minn., George W want you to mm- 'S. send me the CROFT pore the Croft boons with others. Young 100-231 and Fill In P LIBRARY OF PRACTI- mall the coupon attached and we CAL ELECTRIt'ITY r KFMW Houghton, Mich., M. G. Sate- hill send you (ship - TRANSFORMER the entire set of eight 15" ping charges prepaid). for ren 50-266 volumes fcr ten days' Free 10 naUon. Exam!- '' days' free examination. If 'atis- KFMX Northfield, Minn., Carleton Col- We take all the risk- Q' factory I will My all charges. send $1.50 In ten lege 500-283 You assume no 4 days and $2 per month until obligation-you pay nothing 519.50 KFNF Shenandoah. Iowa, Henry Field PRACTICE unless has been paid. If not wanted. I will you decide to keep {t, write you for return shipping Seed Co. 500-266 the books. Send instructions. the eou- !t, Upon receipt of my first payment of 11.50 dr KFNG Coldwater, Miss., Wooten's Pon NOW and see the am TAKE ADVANTAGE books 4 I to recelee a copy of Taylor's Transform- Radio Shop 10-254 for yourselL 4 er Practice free of charge, ft rite plainly and KFNL Paso Robles, Calif., Radio OF THIS GREAT Send No fill In all lines.) Broadcast Assn. 10-240 BARGAIN OFFER Money- same KFNV Santa Rosa, Calif., L. A. Drake 5-234 Just the Hom Address KFNY Helena, Mont., Montana Phono- Coupon graph Co. 5-261 City and State KFNZ Burlingame, Calif., Royal Radio Act Now! Company or Employer Co. 10-231 fr Occupation S&I 2-1-25 1040 Science and Invention for February, 1925 Power Call & Wave Letters Location and Name Length Reflex KFOA Seattle, Wash., Rhodes Dept Store 500-455 KFOC Whittier, Calif., First Chris- Radio Receivers tian Church 100-236 KFOD Wallace, Idaho, The Radio Shop 10-224 .L KFOF Marshfield, Ore., Rohrer Elec- 1e.-armas ,.e,,,r.tó ,a tric Co. 10-240 KFOJ Moberly, Mo., Moberly High - School Radio Club 5-246 KFON Long Beach, Calif., Echophone i . REFLEX. Radio Shop 100-234 KFOO Salt Lake City, Utah, Latter RADIO ' z Day Saints University 10-261 KFOR David City, Nebr., David City ! 'RECEIVERS' Tire & Electric Co. (How- ard A. Shuman) 20-226 0 r.tcotrtar/ o KFOT Wichita., Kans., College Hill Radio Club 50-231 KFOU Richmond Calif., Rommel Mfg. Co. 100-254 \2 KFOX Omaha, Nebr., Technical High School KFOY St. Paul, Minn., Beacon Radio 100-245 Service 50-226 to Make KFOZ Fort Smith, Ark., Leon Hudson "I' m Going Real Estate Co 20-233 KFPG Los Angeles, Calif, Oliver S. More Money!" Garretson 10-238 KFPH Salt Lake City, Utah, Harold "I'm tired working for a small sal- C. Mailander 50-242 WHAT REFLEX DO ary. I know I have just as good a head KFPL Dublin, Texas, C. C. Baxter 15-252 on Fred Moore and Bob Roberts, KFPM Greenville, Texas, New Furni- me as ture Co. 10-242 YOU PREFER? for we used to work side by side. But KFPN Jefferson City, Mo., Missouri The new 64 -page book giving they've gone far ahead of me. National Guard, 70th In- finest fantry Brigade 10-242 hookups galore on the low "Whys Because they saw the value REPO Denver, Colo., Colorado Na- cost double duty -reflex circuits of special training, and I didn't. tional Guard, 45th Division Only the reflex can give the maximum Tank Co. 500-231 results on a minimum number of tubes. "But I know better now. If the KFPP Olympia. Wash.. G. & G. Radio It's the inherent principie of tho relies International Correspondence Schools & Electric Shop 20-236 circuit that makes the tube do double KFPR Los Angeles. Los An- duty. Therefore the reflex circuits are for can raise the salaries of men like Fred Calif., AM. the man who wants all the advantages of geles County Forestry De- tho high or low powered tadic set at a low Moore and Bob Roberts, they can raise partmentKFPT S00-231 cost of construction and operation. Salt Lake City, Utah, Cope & 0 The new E. I. Company book gives torn. o mine, too! pleb details on the finest reflex circuits. Johnson 500-268 It gives complete instructions on circuits "If they have helped others to ad- KFPV San Francisco, Calif., Heintz galore. Contains 64 pages, bound by hand- vance, they can help me. To-day-right & Kohlmoos 50-236 some heavy cover printed in two colors. going to send in this coupon KFPW Carterville, Mo., St. Johns Size Is Syr by 7'/r Inches. now-I'm SOLD BY ALL RELIABLE RADIO AND and at least find out what the I. C. S. Church 20-268 NEWS DEALERS can do for me." KFPX Pine Bluff. Ark., First Presby- terian Church 100-242 Prepaid INTERNATIONAL CORRESPONDENCE SCHOOLS KFPY Spokane. Wash., Symons In- Woo 6192-1) Scranton, Penna. vestment Co. 100-283 Without cost or obligation on my part. please tell me KFOA St. Louis, Mo., The Principia 50-261 how I can qualify for the position or in the subject before KFQB Book No. which I have marked an X: Fort Worth, Texas, Search- light Publishing Co. 100-254 BUSINESS TRAINING COURSES KFQC Taft. Calif., Ridd Brothers 13 Business Management Q Salesmanship Industrial Management Advertleing Radio Shop 100-227 PUBLISHED BY Personnel Organization Better Letters EFQD Anchorage, Alaska, C h o v i n Traffic Management Show Care Lettering Supply Co. 100-280 THE E. I. COMPANY Business Law Stenography and Typing Banking and Banking Law PI Business English KFQE Colorado Springs. Colo., Dick- Accountancy (including C.P.A.) Civil Service enson -Henry Radio Labora- The Consrad Company Nicholson Cost Accounting Railway Mail Clerk tories 10-224 Sole Distributors Bookkeeping Common School Subjects Private Secretar CI High School Subjects KFQF Minneapolis, Minn., Donald A. 233 Fulton St. New York City Spanish f1 French OIllustrating Boult 10-224 TECHNICAL AND INDUSTRIAL COURSES KFQG Los Angeles, Calif., Armory Electrical Engineering p Architect Exposition Park, Southern l Electric Lighting Architects' Blue Prints California Radio Assn 100-226 Mechanical Engineer in Contractor and Builder KFQH Mechanical Draftsman Architectural Draftsman Hillshourgh, Calif., Albert Machine Shop Practice pi Concrete Builder Sherman 50-231 Railroad Positions 0 Structural Engineer KFQI Culver City, Calif., Thomas H. Gas Engine Operating Chemistry ['Pharmacy Ince Corp. 100-234 Civil Engineer Automobile Work Surveying and Mapping Airplane Engines KFQJ Oklahoma, Okla., Harbour- Metallurgy Mining Agriculture and Poultry Longmire Co. 50-236 Steam Engineering O Radio Mathematics "RADIO'S nsrad KFQR Fayette, Mo., Democrat Leader 10-236 FOREMOST PUBLISHERS" Name KFQL Muskogee, Okla., Oklahoma Assn 20-252 Street 3-6-24 Free State Fair Address KFQM Austin, Texas, Texas Highway Bulletin 100-268 City State KFQN Portland. Ore., Third Baptist Occupation Church 5-283 KFQO Russell, Kans., Meier Radio Persons residing in Canada should send this coupon to the Stop Snugint /nternotionat Correspondence Schools Canadian, Limited, Shop 10-261 Montreal. Canada KFQP Iowa City, Iowa, George S. Get rid of nasty Catarrh. Stop sneezing, Carson, Jr. 10-224 ' hawking. wilting and coughing- You Okla., Walter L. weren't born with that disgusting disease. KFQR Oklahoma, You acquired it because your Lungs, Ellis 50-250 Liver, Bowels, Kidneys, and all other Course for nee of ambi- KFQT Denison, Texas, Texas National organs designed to eliminate waste matter tion and limited time. are not Electrical Over 4000 men trained. Guard, 36th Signal Company 10-252 functioning properly. Now your Condensed course in Theoretical and Practical Elec- vitality is falling, your tongue is cooled, tncel KFQU Holy City, Calif., W. Riker 100-234 your breath Is foul and your Nose. Throat, including KFQV Omaha, Nebr., Omaha Grain Lungs and every part of your body are close- loaded with Exchange 100-231 It: Catarrh poisons. Don't waste Engineering the 13o your time and money on dope and and Bend, C. F. drugs, sublerU of Mathematics Mechanical Drawing KFQW North Wash., Sprays and washes, pills and powders. taught by experts. Students construct motors. install Knierim Photo Radio & These can never help Sou. The only way wiring, test electrical machinery. Course complete Electric Shop 50-248 to gain relief Is to drive out the waste KFQX Seattle, Wash., Alfred M. Hub- ' - matter and build up your body-all of it bard 500-233 -through Nature's Laws. In One Year ISTRONGFORTISM-The New Science of Established in 1893 Prepare for your KFQY Belden, Nebr., Farmers State Health Promotion will rebuild and restore profession in the most Interesting city Bank 10-273 every part of your body and aid Nature In In the world. Free catalog. KFQZ Hollywood, Calif., Taft Radio forever banishing Catarh and all other BLISS ELECTRICAL I SCHOOL Co. 250-240 aliments. guarantee it. twit 106 Tahoma Ave., Washington. D. C. Mention the ailments on which you want KFRB Beeville, Tex., Hall Brothers 250-248 special and send with for - information toe KFRC San Francisco. Calif., Radioart postage, etc.. on my "Practical Talk on Catarrh," and my free book, "Promotion Studio, Whitcomb Hotel 5-280 and Conservation of Health, Strength and KFRF Alexandria, La., W. R. Brown 10-242 Mental Energy," c^^d for them RIGHT TRONGFORT PrintCards. Stationery. Your Circulars. Own Paper. etc. KFRG St. Louis, Mo , Cleveland High NOW. Complete Outfits 58.85 up. Save money School 20-236 The Perfect Mtn LIONEL STRONGFORT Print for others, big profit. All easy, rules KFRII Grafton, N. D., Martin L Physical and Health Specialist sent. Write for catalog prenses type, paper Dept. 1709 Newark, New Jersey etc. THE PRESS CO., L-47, Merlden, Conn, Monson 10-268 Science and Invention for February, 1925 1041 Power Call & Wave Letters Location and Name Length This Year, Thousands of Men Will KFRI Denver, Colo., Reynolds Radio Co. 5-224 On moving train in West- ern Nebraska. ucceed in Dra f tiñg KFRJ Conway, Ark., Guy Simmons, Jr. 10-250 KFRL Grand Forks, N. D., Men's _Will You Be One of Them Club of First Presbyterian Church 10-240 KFR11I Fort Sill, Okla., Lieut. James FREE Trial Lesson Points the Way P. Boland, U. S. A. 50-263 IC FR Hanford, Calif., M. Laurence TEN months from today you can be an expert draftsman. If you Short 5-224 are making less than $200 per month with limited prospect for K FRO Fort Worth, 'fex., Curtis Print- facts are addressed to you. 50-246 advancement ... these ing Co. is KrSG Los Angeles, Calif., Echo Park More than 50,000 draftsmen are needed every year. That what Evangelistic Assn 500-278 makes drafting ... when the man is properly trained ... one of the K FS Y Helena, Mont., Van Blaricom surest and shortest roads to increased income. In a letter to Mr. Co. 10-261 Technical College, I\ Ir. KGB Tacoma, \Vaslt., Tacoma Daily Charles W. Morey, President of the Chicago Ledger 50-252 George W. Hand, Assistant to the President of the Chicago and KGG Portland, Ore., Hallock & Northwestern Railway, writes: Watson Radio Service 50-360 no KGO Oakland, Calif., General Elec- "Good draftsmen are hard to find and they experience difficulty tric Co. 1000-312 in obtaining remunerative employment." KGU Honolulu, Hawaii, Marion A Mulrony 500-360 KG W Portland, Ore.. Portland Morn- Short Home -Study Course beenth ing Oregonian 500-492 engineers. KGY Lacey, Wash., St. Martins Col- ing drafting for 21 years. Our instructors are practical lege 5-258 They train you with practical jobs. Rates are low ... payments Kill Los Angeles. Calif., Times- easy. When you enroll, we include a $25 "lifetime" drawing outfit. Mirror Co. 500-395 KllQ Seattle, Wash., Louis \Vasuter We send you without (Excelsior Motorcycle & Bi- Lesson Idea a trial les- cycle Co.) 100-360 The Trial obligation KJQ Stockton, Calif., C. O. Gould 5-273 son in drafting. We want you to see what drafting is like . . . we KJ R Seattle, Wash., Northwest Ra- want you to know our method of teaching by mail. Our course has dio Service Co. S0-283 been simplified and perfected through 21 years of teaching experi- K1S Los Angeles, Calif., Bible In- you will like, stitute of Los Angeles 750-360 ence but we want you to judge for yourself whether KLS Oakland, Calif., Warner Bros this fascinating, well -paid work. Radio Supplies Co. 250-360 KLX Oakland, Calif., Tribune Pub- We send you also a book lishing Co. 500-509 40 -page Book, free: of interesting facts on the I:L7. Denver, Colo., Reynolds Radio our courses Co. 230-283 field of drafting. This book gives you in complete outline KMJ Fresno, Calif., San Joaquin in structural, architectural, electrical and machine drafting. It in- Light and Power Corp 50-248 troduces you to our instructors; tells you what prominent men say KMO Tacoma, Wash., Love Electric about drafting ... where draftsmen are employed ... and at what Co. 10-360 it tells you ENT Eukak Bay, Alaska, Walter salaries ... what a draftsman's opportunities are ... Hemrich 100-263 how ... and why .. many of our students have increased their KOB State College, N. M., New salaries even before finishing their courses. Mexico College of Agricul- ture and Mechanic Arts 500-360 Most men at the top in engineering started KOP Detroit, Mich., Detroit Police as draftsmen. Many of our students who Department 500-286 learn drafting in spare time through Home - 'Drafting KPO San Francisco, Calif., Hale positions Bros. 500-423 Study come to Chicago and secure 'Engineering KQP Hood River, Ore., Apple City at greatly increased salaries as draftsmen in and Architecture Radio Club 10-360 engineering, construction, railroad, architec- KQV Pittsburgh, Pa., Doubleday - firms, etc. Then evenings in the Hill Electric Co. 500-270 tural ... Chicago Technical Col- KQW San Jose, Calif., Charles D. college classroom ... they continue their lege, founded in 1904, Herrold ' 50-360 study of engineering or architecture. Many enrolls over 1000 men each year in resident day ERE Berkeley, Calif., Berkeley Daily L of them rise quickly to positions paying Gazette 50-275 $350, $400 per month. Many enter and evening courses. KSD St. Louis, Mo., Post Dispatch 500-546 $300, Diplomas in engineering KT1V Seattle, Wash., First Presby- Howbígafieldis their own business. Others become chief and architecture are terian Church 750-360 draftsmen and executives. The field of prog- granted at the end of KHO San Francisco, Calif., Exam- DRAFTING? ress opened up to them in this way is two years. The Degree iner Printing Co. 150-360 of B. S. is conferred at A structure like the really limitless. the end of three years in KWG Stockton. Calif., Portable Wire- Building.recent- less Telephone Co. Temple the day course. Short 50-360 lycomploted in Chicago, courses, also, in Draft- K\VH Los Angeles. Calif., Los An- requires approximately geles Examiner ing, Plan Reading. Esti- 250-360 3000 mechanical draw- Send Coupon Today mating, etc. KYQ Honolulu, IIawaii, The Electric ings to guide Its build- Thousands of men will succeed in drafting Shop 100-270 ers. Every floor, every From this famous Col- EY\V Chicago, Ill., Westinghouse girder, every stone must this year. Will you be one of them? lege of Engineering come Electric & Mfg. Co. 1000-536 first be "laid out on these Home - Study K'/,M Oakland, Calif., Preston D. paper." Every cottage courses in Drafting. Allen 100-360 and every skyscraper WA AB New Orleans, La., Valdemar must be drawn ... me- Opportunities Jensen 100-268 chanically and to scale W \AC New Orleans, La., Tulane ...before the builder can in Chicago University 400-360 interpret the ideas of the For those who can come WA \D Cincinnati, Ohio, Ohio Me- architect...every coun- to Chicago. there Is a chanics Institute 25-360 try highway and city splendid opportunity to WA A F Chicago, Ill.. Chicago Daily street. every engine and learn drafting while Drovers Journal 200-286 machine...whereverany- earning expenses In WAAM Newark, N. J., I. R. Nelson thing is built, there the part-time positions. If Co. 250-263 draftsman is essential. interested, write for 52 - \V AAN Columbia, Mo., University of Send the Coupon page Blue Book. Missouri 50-254 \VAA\V Omaha, Neb., Omaha Grain Exchange 500-286 \VABB Harrisburg. Pa., Harrisburg Sporting Goods Co 10-266 W 1BD Dayton. Ohio, Parker High ChicagoTECH LA I CAL College School 5-283 WABH Sandusky, Ohio, Lake Shore Chicago Tech Building, Dept. 245B, 118 East 26th Street, Chicago Tire Co. 10-240 \VABI Bangor. Me., Bangor Railway & Electric Co. 100-240 W \BL Storrs. C o n n.. Connecticut Chicago Technical College, TRIAL Name Agricultural College 100-283 Dept. 245-B, 118 East 26th Street, Address W\BM Saginaw. Mich., F. E. Doherty I Chicago, Ill. Automotive & Radio Equip- Gentlemen: Send me, without cost LESSON ment Co. 100-254 f or obligation, your Trial Lesson City WABN La Crosse, Wis., Ott Radio, and 40 -page Booklet of Facts Inc. 500-244 Abort Drafting. FREE State WABO Rochester, N. Y.. Lake Avenue Baptist Church (Hickson Electric Co.) 10-283 1042 Science ánd Invention for February, 1925 Power Call & Wave Letters Location and Name Length er WABP Dover, Oh i o , Robert F W eidig 200-266 $700 WABQ Haverford, Pa., Haverford Col- Direct lege Radio Club 50-261 WABR Toledo, Ohio, Scott High from the School 50-270 Maker WABU Camden. N. J., Victor Talking aweek Machine Co. 50-226 WABW \Vooster, - Ohio, College of from Aisown \Vooster 20-234 \VABX Mount Clemens, Mich. (near), Photo, rn2phStudio Henry B. Joy 500-270 WABY Philadelphia, Pa., John Magal- "My Income now averages from $700 to writes di, Jr. 50-242 onhaelo rash- ownsowl his wwn photographieek," c studio WABZ New Orleans, La., Coliseum tenable Fifth Avenue. New York. He adds. Place Baptist Church 50-263 "11íy poem It studies bring me as much as $250 donen." WAHG Richmond Hill, N. Y., A. H. Hundreds of others are gaming big money Grebe & Co. 500-316 -'.werywhere. Amazing growth of Professional \VBAA \Vest Lafayette, Ind., Purdue Photography offers chango of a lifetime; high salaried University position or your own business. $20 to $75 a 250-283 week in spare lintel \VBAN Paterson, N. J., Wireless Phone Corp. 100-244 Learn at Home No previous experience or special ability . \VBAO Decatur, Ill., James Millikin needed. New easy method makes you a University 50-275 Professional Photographer in spare hours at \VBAP Fort Worth, Texas, Wortham- home. Famous experts of New York Insti- tute of Photography train you by mall. All Carter Publishing Co. (Star- branches: Motion Picture. Portraiture, Telegram) 1000-476 Commercial, News Photography. Earn while WBAV Columbus, Ohio, Erner & Hop- learning. kins Co. 500-423 MOTION PICTURE OR 5 x 7 VIEW CAMERA FR 'E WBAX WilkesBarre, Pa., John H. Your choice absolutely free. Motion down! Stenger, Jr., 20-254 Picture Camera takes real Motion Plc- you pre- NOTE: If \VBAY New York, N. Y., tures on standard professional film used ter to come to our -and direct from factory Western by all theatres-View 0 Electric Co. 500-492 Camera Is latest New York or Chica - professional model for all still photog- go Studios for per- Only $1.00 down buys the WBBA Newark, Ohio, Plymouth Con- raphy; genuine anastigmat lens. asnal Instruction, famous Studebaker Insured Watch gregational Church 20-240 Write For Book. Handsome big new day or evening des - direct from the factory at the low book explains wonderful opportunities: sea write for Cats - WBBD Reading, Pa., Barbey Battery positions factory price. Choice of 54 newest Service paying $50 to $250 a week, log R-82 to nearest Beauty Cases, white gold. 50-234 how to start your own business, how to chic eas: 111 W.36th Art in earn money In spare green gold or yellow gold effects; 8 WBBF Atlanta. Ga., Georgia School time. Send post- SL,N. Y.: or 630 S. of card or letter today for FREE BOOK Wabash Av,Chieago. handsome dial designs. Mail coupon Technology 500-270 and free Camera offer. for beautiful Style Book in colors- WBBG Mattapoisett, Mass., Irving NEW YORK INSTITUTE OF PHOTOGRAPHY Sent Frees Verinilya 500-248 Dept. 822, 143 West 36th St. New York, N. Y. \VBBH Port Huron, Mich., J. Irving 21 Jewel "Extra Bell 50-246 thin WBBL Richmond. Va., Grace Cove- YOU TOO-CAN PLAY THE -k-/- nant Church 5-283 WBBP Petoskey. Mich., Petoskey High STUDEBAKER School HAWAIIAN G UIT 10 & 100-246 JUSTAS THE HAWAIIANS D e WBBR Rossville. N. Y., Peoples Pul- _ The Insured Watch pit Assn. 500-273 PLAY ALL THE LATEST HITS WBBS New Orleans, La., First Bap- Has 21 Jewels -8 adjustments-and is insured for the ONLY 4 lifetime of the owner. The masterpiece of timepieces tist Church 50-252 MOTIONS at an amazingly low price. WBBT Philadelphia, Pa., Lloyd Bros 5-234 used in playing WBBU Monmouth. Ill., Jenks Motor the fascinating Sales Hawaiian Gut - Watch FREE! Co. 10-224 tar. Chain WBBV Johnstown, Our native For 'a limited time we are offering a beautiful Watch Pa., Johnstown Ra- Hawaiian instruc- Chain FREE. Write while offer lasts. dio Co. 5-248 tors teach you to master them WBBW Norfolk, Va., Ruffner Junior quickly. Pictures show how. kverytlting explained clearly. Mail Coupon High School 50-222 PLAY IN for FREE Book WBBY Charleston. S. C., Washington HALF HOUR today After you get the 4 easy mo- Mail coupon for magnificent Studebaker Book Light Infantry 10-268 tions you can play harmonious of Advance Watch Styles. Find out how you can WBBZ Indianapolis, Ind., Nohle B chords with very little practice. buy direct from the factory-save money and own one Watson 50-227 40,000 students have learned to of the finest watches made. The Book shows 54 newest play in this easy, pleasant way. , thin -model designs in Art Beauty Cases. Sent FREE! WBL \nthony, Kans., T & H Radio EASY LESSONS Co. 100-254 The42 printedlemwns with a great many picturezi nude it easy to learn STUDEBAKER WATCH CO. WBS Newaik, N. J., D. W. May, to Dept. H.97 South Bend, Indiana Inc. 50-360 how tore d note. No revi mnim- teal knowledge necessary. Y Canadian Address: Windsor, Ontario WBT Charlotte, N. C., Southern learn to play any kind of music, and Ask for Ladies' Bracelet Watch Folder Radio Corp. 250-360 pay mi van Play. Springfield, FREE GUITAR Ask for Jewelry Folder \VBZ Mass., Westing- Asa special offer to new student. house Electric & Mfg. Co 1000-337 we give this full mare, high grade In. ' ,etrumeot free of charge. it is sent WCAD Canton. N. Y., St. Lawrence at once without red tape or dly. STUDEBAKER WATCH CO. I Dept. H-97 South Bend, Indiana University 250-280 WRITE AT ONCEi- WCAE Pittsburgh. S d your a at once and let ua I Please send me your Free Book of Advance Watch Pa., Kaufmann & t tell you ail about the 65 rimy lessons Styles and particulars of your $1.00 down offer. Baer Co. 500-462 and the tree guitar. You have e.ery- N ng to gain, Don't put it otf. A (¡you lice in Canada send your inquiry I \VCAG New Orleans, La., Clyde R cord w now nDe- boor Canadian office: Win. Ontario. Randall 50-268 etml otter:was and easy %gems First Hawaiianlr Conservatory - Name WCAH Columbus, Ohio, Entrekin Special courses on Vio- of Music. Inc. Electric Co. 100-286 lin Tenor -Banjo Ban- 233 Broadway (Woolworth Bldg.. Address York. WCAJ University Place, Neb., Ne- jo-llkalela and Ukulele Drpt.40,New N. Y. City State braska \\'eslcyan University 500-280 r-1 Cheek here for Cheek herehe for WCAK Houston, Texas, LadlLadles Watch Folder Alfred P L_ Jewelry Folderwonsim I Daniel 10-263 "LIGHTING FIXTURES" WCAL NorthFetd, Minn., St. Olaf READY TO HANG College 500-360 Direct from manufacturer. WCAO Baltimore, Md., Sanders & Completely wired Including glassware. Stayman Co. 50-275 Send for Catalogue No. 26 (Just off the Press) WCAP Washington, D. C., Chesa- *NI Special Proposition to Dealers Magnified 225 Diameters peake Sr Potomac Telephone it1 Co. 500-469 ERIE FIXTURE SUPPLY CO. This is what the tip of a fly's leg WCAR San Antonio. Texas, Southern Desk B Erie. Pa. _ - t is like when seen thru the Radio Corporation of Texas 100-360 WCAS Minneapolis, Minn., William i Í ULTRALENS Hood Dunwoody Industrial AGENTS 500% PROFIT MICROSCOPE Institute 100-280 GENUINE GOLD LEAF LETTERS WCAT Rapid City, S. D., South Da- Guaranteed to never tarnish. Anyone can Any amateur can kota State School of Mines 50-240 put them on stores and office windows. Iq Immediately start V - I using his Ultra - WCAU Philadelphia, Pá., Durham & Enormous demand, large profits. Paul Clark r lens to examine Co. 250-286 says : smallest day $28.70. R. L. Reel made 11 the edge of a WCAV Little Rock, Ark., J. C. Dice $920 in two months. Write today for free t razor. the mesh sample and liberal offer to general agents. of a cotton shirt. Electric Co. 10-360 t +: f the bacteria I n METALLIC LETTER CO.. 403 N. Clark Street. Chicago dirty water. No WCAX Burlington, Vt., University of technical training Vermont 100-360 "BOW and q $7.50 for Complete Outfit Prepaid. required, yet hun- dreds of scien- WCAY Milwaukee, Wis., Hotel Ant- tists and teachers are using this Instrument. Gives enor- lers, Milwaukee Civic h' NEES"s UNSIGHTLYCK- mous magnification and perfect definition. Send $7.50 for Broadcasting Assn. complete outfit. Send for descriptive literature. 250-266 Send for Booklet showing photos of men \VCBA Allentown, Pa., Charles W. with and without the Perfect Leg Forms Scientific Apparatus Corp., Dept. 203, Milton, Pa, Heimbach 10-280 PERFECT SALES CO., Dept. 50 140 N. Mayfield Ave. Chicago, Ill. ' Science and Invention for February, 1923 1043 Power Call & Wave Letters Location and Name Length WCBC Ann Arbor, Mich., University - of Michigan 200-280 WCBD Zion, Ill., Wilbur G. Voliva 500-345 \VCBE New Orleans, La., Uhalt Brothers Radio Co. 5-263 WCBG Pascagoula, Miss. (portable), Gt`EvdYR Q 192a. Howard S. Williams 10-268 N A4t1 WCBH Oxford, Miss. (near), Univer- e;Cp sity of Mississippi 10-242 WCBI Bemis, Tenn., Nicoll, Duncan & Rush 50-240 41tet CO Qáá WCBJ Jennings, La., J. C. Mans 10-244 t\i óOf WCBK St. Petersburg, Fla., E. Rich- 4t `\ Stet Hall gemSSoe ard 500-266 ,1pYl., t a't 41et 1 34 tpr óatd e the tets WCBL Houston, Me., Northern Radio s k Mfg. Co. 50-280 en. my eháoll 9pSP, sLa;ty4ewtl WCBO Memphis, Tenn., Radio Shop, SnBtOn G áe st Inc. 20-250 m 9 tbRemltOn ty WCBQ Nashville, Tenn., First Baptist 1nenet to tWtb t 4telat° áa Church 100-236 mant et t 3 late tpDdaca/1 bee 1 e itc Yal eaident WCBR Providence, R. I. (portable), 5 a pas aºot Charles H. Messter 5-246 e' 0 man lv Yr am °t y ttt7nGn pOó se t t the 1 WCBT \Vorchester, Mass., Clark Uni- uYlSa tll. versity 250-238 St astt 1 o ne C e tD»es°pt \VCBU Arnold, Pa.. Arnold Wireless 41-a9b .1Y2"'emoan ghe 9elt. %°ttL,t,tee yo. ttade9 t V4°n sotld Supply Co. (F. J. Ambrose) 50-254 "e. WCBV Tullahoma, Tenn., Tullahoma in a:115154 Gt''C°11e Y t n° J=e was al5 8 Stt1e Radio Club 10-252 po nanl Eta 1 AS t9Ty to°onti b1e 1 Ca oot 1 n seGte Y ct et WCBW Macon, Ga., George P. Rau - °vetl. Sa thete Y°ttaa heav áe' ot kin, Jr., and Mitland Solo- utentot mY one 1111 pgtpnavels nnísabe t9 vsea °utuaó éet man 10-226 Ydetln89.'11:: the o1p R my L1 pot ot rá tp °tte WCBV Buck Hill Falls, Pa., Forks IX' cQ Electrical Shop 10-268 ate tyoú Sittle WCBZ Chicago Heights, Ill.. Coppo- oQnt11 telli Music to 9Fe snatye Bros. House 50-248 t°t ndatd a loah Iteon° vete ie WCCO Minneapolis, Minn., \Sashbuno- stchne Is ttdntaee vleattlone the Crosby Co. 500-117 ''114n 1nd.-. vbeot s11Ú1 at WCK St. Louis, Mo., Stix-Baer & -1a bin, o tt° Dry Co 1s St. Eotta ent Fuller Goods 100-360 tot te b ety \VCX Detroit, Mich., Detroit Free Rent a6tOn.a s Press 500-517 caoh! nz \VDAE Tampa, Fla., Tampa Daily Times 250-360 \VDAF Kansas City, Mo., Kansas City Star 500-411 \VD.1G \marina, Texas, J. Laurance Martin 100-263 WDAH El Paso, Texas, Trinity Meth- odist Church (South) 50-268 WD.\R Philadelphia, Pa., Lit Brothers 500-395 fn \VDAS \Vorcester, Mass., Sam Waite s Radio Shop 10-360 \VDAU New Bedford, Mass., Slocum _ & Kilburn 100-360 WD 1Y Faro, N. D., Radio Equipment Corporation 50-244 .`:" sobusal, A. + WDBB Taunton, Mass., H. Waite & Co. 10-229 \VDBC Lancaster, Pa., Kirk, Johnson "I am not going," Randall told men in eh, overcrowded boat. & Co. 50-258 the WDBD Martinsburg, W. Va., Berman s soul) stick here and whys you get E. Burns 5-268 re San Francisco ask Cappy Ricks \VDBF Youngstown, Ohio. Robert G to send a tug out to look fee me." Phillips 50-246 WDBTI Worcester, Mass., C. T. Shear Li Co. 100-268 WDBI St. Petersburg, Fla., Radio Specialty Co. 20-226 u WDBJ Roanoke, Va.. Richardson -Way- land Electrical Corporation 50-229 "IT'S A REAL TYPEWRITER" WDBN Bangor, Me.. Maine Electric Light & Power Co. 5-252 The Remington Portable has won the endorsement of Peter B. WDBO Winter Park, Fla., Rollins Col- lege 50-240 Kyne, just as it has won the endorsement of prominent people WDBP Superior, Wis., Superior State the world over-by its outstanding superiority. Its success has Normal School 50-261 been phenomenal. WDBO Salem, N. J., Morton Radio Many present Supply Co. 10-234 owners, like Mr. Kyne, have operated other WDBR Boston, Mass., Tremont Tem- typewriters. In the Remington Portable they have found a com- ple Baptist Church 100-256 pact machine which meets every requirement, built to do beauti- WDBS Dayton, Ohio, S. M. K. Radio ful work, and possessing every feature common to the big machine, Corn. 5-283 WDBT Hattiesburg, Miss., Taylor's even to the four -row standard keyboard. Book Store 10-236 Why should you continue to write in the old-fashioned, \VDB\V Columbia, Tenn., The Radio slow, tedious, long -hand, when with a Remington Portable Den 20-268 you can turn WDBX New York, N. Y.. Otto Baur 5-233 out a beautifully clear and legible printed page, WDBY Chicago. III., North Shore Con- with far less time and effort ? It's time to buy a Remington gregational Church 500-258 Portable. Sold by all Remington branches, and over 1VDBZ Kingston. N. Y.. Boy Scouts 5,000 dealers. Easy terms. of America (Ulster County Council) 5-233 Illusrrared"For You-For Everybody" will pl/ '111- WDM Washington, D. C., Church of é be sent upon request. Address Department Lit. ,y' the Covenant 50-234 WDZ Tuscola. Ill., Tames L. Bush 10-278 tq t-eeiOr.. r ! WEAA Flint. Mich., Police REMINGTON TYPEWRITER COMPANY 1trea.re !' Building O Frank D. Fallaiu 50-280 374 Broadway, New York City . 1VEAF New York. N. Y., American Remington Typewriter Company of Canada, Limited & Telco. Teleg. Co. 500-492 Main OFice,68 King Street, Vu est, Toronto WEAR \Vichita, Kans., Wichita Board of Trade 50-280 \NEAT Ithaca, N. Y., Cornell Univer- sity 500-286 \VEAJ Vermilion. S. D,k., University of South Dakota 100-283 \VEAM North Plainfield. N. J.. Bor- ough of North Plainfield 1so-286 WEAN Providence, R. I. Strenard Co 100-273 REMINGTON WEAO Columbus. Ohio, Ohio State University 500-294 WEAP Mobile, Ala., Mobile Radio Co 100-360 WEAU Sioux City. Iowa, Davidson Bros. Co. 100-275 WEAY Houston. Tex.. Iris Theatre 500-360 Portable Typewriter WEB St. Louis, Mo., Benwood Co 100-273 "VEBA Highland Park, N. J., The THE RECOGNIZED LEADER-IN SALES AND POPULARITY Electric Shop 15-233 1044 Science and Invention for February, 1925 Power Call & Wave Letters Location and Name Length WEBC Superior, \Vis., Walter C PRICES REDUCED Bridges 10-242 WEBD \nderson, Ind.. Electrical Equipment & Service Co 10-246 WEBE Cambridge, Ohio, Roy \V. Wal- ler 10-248 WEBH Chicago, Ill., Edgewater Beach Hotel Co. 1000-370' WEBI Salisbury, Md., Walter Gib- bons .15-242 WEBJ New York, N. Y., Third' Avenue Ry. Co. 500-273 WEBK Grand Rapids, Mich., Grand Rapids Radio Co. 20-261 WEBL United States, R. C. A. 100-226 WEBO Hamilton, Ohio, Harry W. A - Fahrlander 5-250 Ú Year WEBP New Orleans, La., E. Budd Yes, to Pay Peddicord 50-280 lowest prices on - WEBQ Harrisburg, Ill., Tate Radio UNDERWOOD, REMINGTON, L. C. SMITH, ROYAL, ' Co. 10-226 and all standard makes on easiest terms ever \VEBR Buffalo, N. Y., H. H. Howell 15-240 offered. Re -manufactured like new by the - \VEBT Dayton, Ohio, Dayton Cooper- famous "Young Process." ative Industrial High School 5-270 10 Days' Trial -5 Years Guarantee WEBU De Land, Fla., De Land Piano Our liberal "direct from factory plan" saves half. 10 without & Music Co. You actually use the typewriter days 5-258 obligation to buy. Let us prove we have the great- WEBW Beloit, Wis., Beloit College 500-283 est typewriter bargains ever offered. Big saving. WEBX Nashville, Tenn., John E. Cain, Big Illustrated Catalog Free Jr 50-263 This interesting valuable book explains fully how WEBY Roslindale, Mass., Young Process of arantees Hobart Ra- feet eervice and strla ofaction. dio Co. 10-226 you highest qualityty,p WEBZ YOUNG TYPEWRITER CO. Est.1911 EARLE E. LIEBERMAN Savannah, Ga., Savannah Radio Send Coupon Now -awte Tho Muscle Builder Corp. 5-280 Young Typewriter Co., Orpt.t ló3 \VEEI Boston, Mass., Edison Electric Illuminating m 654 W. Randolph St., Chicago Co. of Boston 500-303 see°-Sprc4 Send me Free book and Special \VEV Houston, Tex., Hurlburt-Still Reduced Prices. This does not A WART ON YOUR NOSE Electrical Co. 100-263 J obligate me in any way. would not be noticed nearly as much as a frail, WEW St. Louis, Mo., St. Louis Uni- .j weak body. Yet, if you had a wart on your nose, versity 100-280 40 Name. you would worry yourself sick-you would pay WFAA Dallas, Tex., Dallas News & most any price to get rid of it. But what about Dallas Journal 500-476 Address that body of yours. What are you doing to make WFAM St. Cloud, Minn., Times Pub- people admire and respect you? Wake upf Come lishing Co. 10-273 /City State to your senses I Don't you realize what a strong, WFAN Hutchinson, Minn., Hutchinson robust body means to you? It makes no differ- Electric Service Co. ence whether it be in the business social world 100-286 or WFAV Lincoln, Nebr., University of -everybody admires the strong, robust fellow- Nebraska everyone despises the weakling. 250-275 \VFBB Eureka, Ill., Eureka College 50-240 WFBG Altoona, Pa.,\Villiam F. Gable I WILL TRANSFORM YOU Co. 100-261 art E $1 make weak men WFBH New I strong. That's my job. That's York, N. Y., Concourse 'WYE.t_ Postpaid why they call me "The Muscle Builder." I never Radio Corp. 500-273 its. fail. A bold statement, but true. I don't care WFBI Y ' with Camden, N. J., Galvin Radio Instructions how weak you are, I can do the trick. The weak- Supply Co. 100-236 er you are, the more noticeable the results. I've WFBJ Collegeville, Minn., St. John's SEND FOR YOUR FREE been doing this for so many years, it's easy now. University COPY I know how. 50-236 WFBK Hanover, N. H., Dartmouth In just thirty days, I'm going to put one full College inch on those arms of yours. Yes, and two inches \\'FBL 100-256 TESTED on your chest. But that's nothing. I've only Syracuse, N. Y., Onondaga started. Now comes the real work. I'm going Hotel 100-286 to broaden your shoulders and strengthen your \VFBM Indianapolis, Ind., Merchants back. I'm going to deepen your chest so that Heat & Light Co. 250-268 HOOK-UPS WFBN every breath will literally penetrate every cell of Bridgewater, Mass., Radio SUBMITTED BY USERS OF OUR your lungs, feeding them with rich life-giving Sales & Service Co 200-226 oxygen. You will feel the thrill of life glowing WFBQ Raleigh, N. C., Wynne Radio WONDERFUL TRANSMITTER throughout your entire system. I'm going to Co. 50-252 BUTTON FOR LOUD SPEAKERS tighten up those muscles in and around your WFBR Baltimore, Md., heart, kidneys and stomach. I'm going to shoot Fifth Infan- AMPLIFICATION EXPERIMENTS try, Maryland, N. G. 100-254 a quiver up your spine so that you will stretch \VFBT out your big brawny arms and shout for bigger Pitman, N. J., Gloucester K. ELECTRIC CO. and harder tasks to do. Nothing will seem impos- County Civic League 50-231 sible. WFBU Boston, Mass., Commonwealth 15 PARK ROW NEW YORK Sounds good, doesn't it? You can bet your Radio Association Sunday socks it's good. It's wonderful. And WFI Philadelphia, Pa., Strawbridge the best of it is, don't just promise you these & Clothier I 500-395 tea things-I guarantee them. Do you doubt me? \VGAL Lancaster, Pa., Lancaster Elec- aMtla veme. Come on then and make me prove it. That's tric Supply & Construction if what I like. Co. 10-248 A RAD1295oIO Are you ready? Atta boy! Let's go. \VGAN Pensacola, Fla., Cecil E. Lloyd 50-360 WGAQ Send for my new 64 -page book Shreveport, La., Youree Hotel 150-252 , \VGAZ South Bend, Ind., South Bend Tribune 250-275 ( a Gets stations uscularDevelopment/I i ®- "M \\'GBA Baltimore, Md., Jones Electric Far and near IT IS FREE! - and Clear & Radio Mfg. Co. 50-254 '.r, Igud It contains forty-three full page photographs of myself WGBS New York, N. Y., Gimbel ( and some of the many prize-winning pupils I have trained. Brothers Many of these are leaders in their business professions to- 1000-316 / RAWAY Radio Setº areamazing value... h.q.,. price.. day. I have not only given them a body to be proud M. WGI Medford Hillside, Mass., Amer- FU . Let ,t.tlon, front New York to Fleea-bud and clear. but made them better doctors, lawyers, merchants, etc. Operate with either dry ll, r storagebatterlet. Beautiful ican Radio & Research Corp. 100-360 elect finished In mahogany with new platinum -finished Rome of these came to me as pitiful weaklings. implor- panel. WGL Philadelphia, Pa., Thomas F. J. SATISFACTION GUARANTEED Don't pay sin w 5150. Write ing me to help them. Look them over now and you will for our money -,arbor plan and Ilhrature. marvel at their present physiques. This book will prove Howlett 500-360 an impetus and a real Inspiration to you. It will thrill \VGN Chicago, Ill., The Tribune 2 -Tube Set. - $29.50 you and ask Is through through. All I ten cents to cover (Drake Hotel - Whitestonc 4 -Tube Set - 59.50 the cost of wrapping and mailing end It Is yours to keep. sake Co.) 1000-370 mu:yri wnbnne rnn ever need or. This will not obligate you at all, but for the of your Dealers -Agents: te"Itary Qal Power Call & Wave Letters Location and Name Length \VHAV Wilmington, Del.. Wilmington Will give me Electrical Specialty Co. 100-503 you \VHAZ Troy, N. Y., Rennselaer Poly- technic Institute 500-380 \VHB Kansas City, Mo., Sweeney School Co. 500-411 WHK Cleveland, Ohio, Radiovox Co. 100-283 6 to \VHN New York, N. Y., George Months Schubel 500-360 WHO Des Moines, Iowa, Bankers Life Co. 500-526 \VIAB Rockford, Ill., Art. A. Johnson Garage 50-252 \VIAL Galveston, Tex., Galveston Tri- hicreaseYOUR PAY. bune 100-360 Yoif \VIAD Philadelphia, Pa., Howard R. M iller 100-254 ur name on the coupon means Yes" WIAK Omaha, Nebr., Journal -Stock- t man Co. 250-278 WIK McKeesport, Pa., K. & L. Elec- No, I am not a wizard. I don't claim to have a "corner" What I Give You tric Co. 100-234 on success, here's a fact. Free Book. Send in the coupon but today. I will immediately send WIP Philadelphia, Pa., Gimbel Broth- For fourteen years I have been helping men just like you to make more you our book "Drafting-Your ers 500-509 money, not just a few men here and there, but thousands of men. Success" which tells about Draft- WJAB Lincoln, Nebr., American Elec- Think these facts over-in just a few months time I boosted one man's ing and its opportunities and con- tric Co. 100-229 pay from 82.00 a day to over $300 a month-another now makes as tains proof that l can raise your pay. \VJAD Waco, Tex., Jackson's Radio high as 827.00 a day-another man, after securing my help, went into Free Subscription to Drs fting while he note hires his drafting done, he makes Publication, "The Comps..." Engineering Laboratories 150-360 business for himself and, I will give you free a subscription \VJAG Norfolk, Nebr., Norfolk Daily over 950,000 a year, to our helpful, inspiring publica- News 250-283 tion, "The Compass." Praetical Problems. You will be WJAK Greentott n, Ind., Clifford L. carefully coached in practical White 30-254 $275 Extra in Three Days Drafting work. \VJAM Cedar Rapids. Iowa; D. M. Per- One man saw an ad like this-Sent in the coupon-Enrolled for the I Help You Get A Job. I will ham 20-268' after he received $275 for one drawing help you get a position as a prac- WJAN Peoria, Ill., Peoria Star 100-280 Columbia Course-and shortly tical Draftsman and will give you that he made in his spare time in three days. real, personal help, such as I have WJAR Providence, R. I., The Outlet Do you make money like these men do 1 Does the money in your pay given to thousands of others. Co. 500-360 envelope get you the things you really want or just enough to make you Personal Instruction and Super- \VJAS Pittsburgh, Pa.. Pittsburgh Ra- wish you. too, could have the good things of life that other men have- vision, throughout the Course. You dio Supply House money, independence, success, happiness ? will receive the personal instruc- 500-286 tion and help of Roy C. Claflin, MAKE S50 TO 3100 A WEEK You get the right traini.g when you WJAX Cleveland, Ohio, Union Trust enroll at Columbia. You spend no President of the Columbia School Co. 500-390 Columbia will train you to be an time on long winded theories. You of Drafting and a practical Drafts- WJD Granville, Ohio, Denison Uni- expert Draftsman In your spare time start on actual drawing work the day man of many years experience. versity 10-229 at home by mail. There's a lot of you receive your first lesson. You get Draftsman's Equipment. I room for you if you act now. This right down to brasa tacks and there is will furnish you with a full set of WJJD Mooseheart, Ill., Supreme doesn't mean thát you will be lust an no lost motion. no waste time or effort first class drawing equipment and Lodge, Loyal Order of ordinary Draftsman. but a finished at any stage of the course. From the Drafting instruments, as shown In Professional Draftsman, able to hold beginning you can feel yourself 111 oose . 500-278 very the picture below, when you en- your place among the highest paid making progress, the kind of progress roll. You keep both sets on com- \VJV New York, N. Y., R. C. A.. 750-405 Draftsmen In the land. that makes you confident of yourself pleting the course. \VJZ New York, N. Y., R. C. A.. 500-455 PROMOTION IS QUICK and sure of your success. Consultation Privileges. You WKAA Cedar Rapids, Iowa, H. F We'll qualify you for a high salaried YOU NEED NO PREVIOUS are free to write me at any time Paar 50-278 position in the Diaftlne field and keep for personal advice and sugges- you in touch with openings for Drafts- TRAINING tions regarding your progress. WKAD East Providence, R. I., Charles of is easy ..o men in the big machine shops, in- This course mine under- Diploma. The diploma I will Looff (Crescent Park) 20-240 dustrial plants and United States stand and easy to follow. It is de- give you on completing the course W. Government departments. Men who signed for men who must have the WKAF Wichita Falls, Tex., S. best and who must get the right train- attests to your proficiency as a Radio Supply Co. 100-360 start as Draftsmen are often advanced Draftsman. It is an entering to Chief Draftsmen. Chief Engineers. ing quickly, so as to be able to make wedge to success. WKAN Montgomery, Ala.. United Bat- Production Managers, and so on. more money as soon as possible. tery Service Co. 15-226 Many of my graduates are today Many of my students are qualified, Advice Regarding Government holding such positions as a result of even before they complete the course. Positions. The following are a \VKAP Cranston, R. I., Dutee W. Flint 50-360 my help. These positions pay big Many a man has increased his pay so few of the many positions open in WKAQ San Juan, P. R., Radio Corp. money and lead on to executive soon after enrolling that his course the Government Departments of Porto Rico 500-360 positions of the highest type. Thou- has actually cost him nothing. front time to time. The salaries sands of men have found Drafting to are starting salaries, subject to \VKAR East f ansing, Mich., Michigan .he the stepping stone to some of the SUCCESS CALLS MEN OF Increase: Agricultural College 500-280 American industry. ACTION ONLY Architectural Designer 54,000 biggest positions in a year. - \VKA\ Laconia, N. H., Laconia Radio GET THE RIGHT TRAINING If you are a man of action-if you Chief Draftsman. Naval Aircraft CI ub want success bad enough to reach out 50-254 I started this school years ago. and grab it, clip the coupon now and Factory-S15.04 a day. R. Aeronautical Draftsman, Field \VKBF Cranston, I., Dutee W. Flint 500-286 Today it is a solidly established na- show me that you are a man of action. Service Navy Department 15 KY \VKY Radio tionally known institution, with Keep right on top of this opportunity - Oklahoma, Okla., graduates all over the world. I stand to make real money. Don't go looking S5.20 to $12.50 a day. S hop 100-360 . personally in back of the Columbia for a pair of scissors, tear the coupon We will advise you as to other. WLAL Tulsa, Okla., Naylor Electrical School of Drafting and back of every off and mail it right away. Get government openings from time Co. 100-360 promise, every statement we make. started now. to time. WLAP Louisville, Ky., \V. V. Jordan 20-286 \VLAX Greencastle, Ind., Greencastle COLUMBIA SCHOOL OF DRAFTING Community Broadcasting Roy C. Chilli'', Presides: Station 10-23l Dept. G-115, 14th and T Sts., N.\V Washington,D.C. 1VLBL Stevens Point, \Vis., Wisconsin Department of Markets 500-278 FREE BOOK COUPON WLS Chicago, Ill., Sears, Roebuck & COLUMBIA SCHOOL OF DRAFTING Co. 500-345 Dept G-115, 14th and T Sts.. N. W., \VL\V Cincinnati, Ohio, Crosley Ra- Washington, D. C. dio Corp. 1000-423 s Please send me without charge your free Illustrated book WMAC Cazenovia, N. Y., Clive B. on Drafting, telling me how I can secure your help In se- curing a position as Draftsman. Also enter my name for Meredith 100-261 / free subscription to "The Compass." \\-\1AF Dartmouth, Mass., Round Hills Radio Corp. 100-500-360 FREE DRAFTING OUTFIT Name 1VJIAH Lincoln, Nebr., General Supply We give you free with our course this professional Address Co. 100-254 Drafting outfit. It is yours to keep when you complete \\-M 1K Lockport, N. Y., Norton Lab- the course. City State oratories 500-273 \VM'1N Columbus, Ohio, First Baptist Church 50-286 -: WMAQ Chicago, Ill., Chicago Daily I Agents Wanted! News 500-448 '''.. \VMAV Auburn, Ala., Alabama Poly- Y Salesmen-Distributors technic 500-250 A` to use and introduce attachment Institute that makes Fords run on 94% WMAY St. Louis, Mo., Kingshighway air. 'THERMOSTAT on ex Presbyterian Church . 100-280 boost automatically turns WMAZ Macon, Ga., Mercer University 100-261 down needle valve as engine \VMC Memphis, Tenn., "Commercial warms, exactly as Ford Appeal" 500-500 Manual says do by hand. \VMH Cincinnati. Ohio. Ainsworth - Blancke Auto Thermo Gates Radio Co. 750-309 An AutomatiC Carburetor Control Makes Fords .tare easier winter or WMU Washington, D. C., Doubleday - summer -eaves half gas ando.1-cote Hill Electric Co. 100-261 spas bills onehelf-reduces carbon formationone-half. Sells on night nt¢qo WNAC Boston, Mass., Shepard Stores 100-278 ON ONE TUBE Ford as WNAD Norman, Okla., University of him íy. bill, becameit g1S100 BIG FREE BOOKLET tells the story. California users very 10.000 miles. Cadillac now uses Oklahoma .. 100-254 of CROSS COUNTRY CIRCUIT hear Atlantic Coast, en standard equipment thermostat e \VNAL Omaha. Nebr.. Canada, Cuba, Mexico and Hawaii. Atlantic Coast users eartiretor control under Blanche Omaha Central Breese. You esa make Big Money selling High School hear England to California. Our new plan makes this this wonderful 20-258 set easiest and to build. One In proven device. Riper coca not necea.ary. Blank WNAP Springfield, Ohio, Wittenberg cheapest hour puts will of Your o.p that operation. One tuning control. No soldering. Any oak-.slan you f`room 3250 toout $2,00out 0a montIh profit Bess College 100-275 novice can do it BIG BOOKLET FREE or complete Writ,!r free eirrular. Nowt WNAR Butler, Mo., First Christian Instructions for 25c stamps or coin. take Street Church 20-231 'VESCO RADIO CO. Box SI.117 Oakland. Calif. A. C. Blancke & Co. Dept.9212. Chicagp 1046 Science and Invention for February, 1925 Power Call & Wave Letters Location and Name Length WNAT Philadelphia, Pa., Lenning Brothers 100-250 vl r. WNAW Fort Monroe, Va., Henry Kunzmann 5-360 á WNA X Yankton, S. Dak.. Dakota Ra- dio Apparatus Co. 100-244 WNJ Newark, N. J., Radio Shop of Newark 100-233 WNYC New York, N. Y., City of New York 1000-526 WOAC Lima, Ohio, Page Organ Co 50-266 WOAE Fremont, Nebr., Midland Col- lege 15-280 WOAF Tyler. Tex., Tyler Commercial College 10-360 \VOAI San Antonio, Tex.. Southern Equipment Co. 500-385 \VOAJ Parsons, Kans., Ervins Elec- " Mary, I Owe It trical Co. 15-258 \VOAN Lawrenceburg, Tenn., James - D. Vaughn 200-360 All to You " \VOAR Kenosha, Wis., Henry P. Lundskow 50-229 "T/TR WILLIAMS called me into his office WOAV Erie, Pa., Pennsylvania Na- IV! to -day and told me he was going to tional Guard, 112th Infantry 50-242 raise my salary $50 a month. WOA\V Omaha, Nebr., Woodmen of " 'I am glad to give you this opportu- the World . . 500-526 nity.' he said, 'for the best reason in the \VOAX Trenton, N. J., Franklyn J. world. You deserve it. Wolff 500-240 "'You may not know it, but I've been watching your work ever since the Inter- \VOC Davenport, Iowa, Palmer national Correspondence Schools wrote School of Chiropractic 500-484 me that you had enrolled for a course of 'vol Ames, Iowa, Iowa State Col- home study. Keep it up, young man, and lege 500-360 you'll go far. I wish we had more men WOO Philadelphia, Pa., John Wana- like you.' maker 500-509 "Convincing "And to think, Mary, I owe it all to WO() Kansas City, Mo., Western you! I might still be drudging along in Radio Co. 500-360 Even to the the same old job at the same old salary \VOR Newark, N. J., L. Bomberger if you hadn't urged me to send in that & Co. 500-405 Trained Engineer" I. C. S. coupon!" WOS Jefferson City, Mo., Missouri State Marketing Bureau 500-441 The above quotation of Prof. J. H. More- Bow about you/ Are you always going to work for a croft of Columbia University is taken from small salary? Are you going to waste your natural ability \V PA B State College, Pa., Pennsylva- his endorsement as printed in The Radio all your life? Or are you going to get ahead in a big nia State College 500-283 nay? It all depends on what you do with your spare time. Reading Course illustrating the authorita- \VPAC Okinulgee, Okla., Donaldson tiveness of the data in this set of five books. More than 180,000 men are getting ready for promo- Radio Co. tion right now in the I. C. S. way. Let us tell you what 100-360 we are doing for them and what we can do for you. \vPAJ New Haven, Conn., Doolittle A Complete Radio Education Mail the Coupon To -day Radio Corp. 100-268 In The Radio Reading Course the amateur WPAK Agricultural College, N. Dak , and experimenter will find a whole educa- INTERNATIONAL CORRESPONDENCE SCHOOLS North Dakota Agricultural tion. In the simplest but most complete and Box 6194-D Scranton, Penna. College 50-283 interesting manner you will find the funda- Without cost or obligation on my part, please tell me \V PAR Beloit, Kans., Ward Battery & mental principles representing the Cause be- haw I can qualify for the position or in the subject before Radio Co. 10-236 hind the Effect. How often have you needed which 1 have marked an X: WPAU Moorehead, Minn., Concordia a sure knowledge of the Cause to help you BUSINESS TRAINING COURSES College 10-286 correct a poor Effect or to get the good Effect Business Management WPAZ Charleston, W. Va., John R. you desired? industrial Management I Advertising Personnel Organization Better Letters Koch (Dr.) 10-273 Traffic Management Show Card Lettering WQAA Parkesburg, Pa., Horace A. To Get These Books You Ncéd Business Law Stenography and Typing Beale, Jr. 500-360 ISalesmanship1 Banking and Banking Law Business English Radio SEND NO MONEY ]]NicholsonAccountancy ( Including C.P.A.) Civil Service WQAC Amarillo, Tex., Gish Cost Accounting Railway Mall Clerk Service 100-234 Send No Money-Just your name and ad- ,] Bookkeeping Common School Subjects WQAE Springfield Vt., Moore Radio dress and we will forward the books to you ID Private Secretary High School Subjects News Station 50-275 upon receipt of which you pay the postman °Spanish French Illustrating $1.97 plus a few postage. WQAF Sandusky, Ohio, Sandusky Reg- cents TECHNICAL AND INDUSTRIAL COURSES ister 5-240 'DElectrical Engineering (] Architect Sole Distributors ]Electric Lighting Architecta' Blue Prints WQAM Miami, Fla., Electrical Equip- ]Mechanical Engineer Contractor and Builder ment Co. 100-283 CI Mechanical Draftsman Architectural Draftemar Pa., Times 100-280 Machine Shop Practice Concrete Builder WQAN Scranton, Scranton The Railroad Positions - Structural Engineer W uAO New kors, N. Y., Calvary Gas Engine Operating Chemistry Pharmacy Baptist Church 100-360 old' Engineer Automobile work WQAQ Abilene, Tex., West Texas Consrad Company Surveying and Mapping Airplane Engines Radio Co. (Abilene Daily RMetallurgy O Mining Agriculture and Poultry 233 Fulton St., NewYork, N. Y. steam Engineering O Radio Mathematics Reporter) 100-360 \VQAS Lowell, Mass., Prince -Walter Co. 100-266 Name WQAX Peoria, Ip., Radio Equipment Street 3-e-24 Get Double Mileage Address Co. 100-248 Fords \VQJ Chicago, Ill., Calumet Rainbow City Efate Broadcasting Co. 500-448 With New Invention WRAF Laporte, Ind., The Radio Club 10-224 Simple Device Works Wonders Occupation WRAL St. Croix Falls, Wis., North- Persons pp should ar Correspondencedwboosn Schools Canadiu,,ertional Limited ern States Power Co. .. 100-248 The most amazing and remarkable invention that i +.,rreal. Canada \VRAM Galesburg, Ill., Lombard Col- has come to light in regent years has just been pro- lege 100-244 duced by Robert Martin of Chamberlain, S. D. \VRAN Waterloo. Iowa, Black Hawk Fords that were formerly making only 12 to 14 Electrical Co. 10-236 miles on a gallon of gas are now getting from .28 to MAKE MONEY. \VRAO St. Louis. Mo., St. Louis 43 miles, by using this new attachment. This mar Radio Service Co. 10-360 vclous invention is a simple affair of aluminum and AT HOME \VRAV Yellowy Springs, Ohio, Antioch glass and can be installed by anyone in just a few College 100-242 minutes. In addition to increasing mileage, it filter, YOU ran earn good money at home in your spare \VRAW Reading, Pa., Avenue Radio every drop of gasoline fed to the cylinders and time making show cords tor us. No canvassing & Electric Shop 10-238 removes every particle of carbon at the same time. or soliciting. We show you how by our new simple WRAX Gloucester City, N. J., Flex Mr. Martin guarantees it to increase mileage on any method. We supply both men and women with work oñ s Garage 100-268 ear and is willing to give one free to any person who at home, no matter where you live and Day you cash WRBC Valparaiso, Ind.. Immanuel will help him introduce it. Write Robert Martin, for all work completed each week. Full particulars Lutheran Church 500-278 800.24 Somers Bldg., Chamberlain, S. D., and ask and booklet free. Write today. \VRC Washington. D. C., Radio Corp. for his free sample offer. AMERICAN SHOW CARD SYSTEM, LTD. of America 500-469 110 Adams Building Toronto, Canada WREO Lansing, Mich., Reo Motor Car Co. 500-288 \VRK Hamilton, Ohio, Doron Bros. - RADIO SETS - - AUTO BODIES Electrical Co. 200-360 SEND FOR THE INTERNATIONAL CATALOG WRL Schenectady, N. Y., Union Col- Our net list. (- (a Fine Tone _ 61 price t lege 500-360 Radio S e t s; \VRM Urbana, Ill., University of Illi- @ Musical r'!r r''.. and auto nois y2 Instrume nts ^ `i b o d lee for 500-273 We haven wonderful copyrighted eretem of tee.iñgg note Fords t \VRR Dallas. Tex.. City of Dallas, music b sl To first pupils n each locality we wll give free a 120 wholesale Iolin Tenor Banjo, Ukulele tiawaiun-Guitar, Banjo, Man- - Police and Fire Signal De- doÍorbn, Banjo-flkulele, Banjo-Mandolin. Cornet or Banjo -Guitar abso- °r Prices. Ben .,. Is partment 30-360 lutely free. Also teach Piano and Organ. Very email charge for -° r r Ilne el WR\V Tarrytown, N. Y., Tarrytown Four lewone will teach you several piece. Over big money by buying 10Ü,0ÚÓ successful pl . W guarantee ell or no charge. free. Write today, dam: - Direct I roas Factory Radio Research Labora- Complete outfit Dept }1 19 ado obligation. lute:nath-eel Body Works, 914 W.Ohlo St.,Dept.4,Chleago,I1i tory 500-273 Slingerland School of Music.1815 Orchard St., Chicago. Ill, Science and Invention for February, 1925 1047 Power Call & Wave Letters . Location and Name Length WSAC Clemson College, S. C., Clem- son Agricultural College 500-360 WSAD Providence, R. I., J. A. Fos- ter Co. 100-261 \VSAI Cincinnati, Ohio, United States Playing Card Co. 500-309 WSAJ Grove City, Pa., Grove City College 250-258 . \\-SAP New York, N. Y., City Tem- ple, Adventist Church 250-263 1VSAlt Fall River, Mass., Doughty & \\ etch Electrical Co. 100-254 41 WSAU Chesham, N. H., Camp Marien- et y t feld 10-229 _ r 4011. WSAV Ilouston, Tex., Clifford W. Vick Radio Construction Co. 100-360 ,Ws \\'SAX Chicago, Ill., Chicago Radio Lab. 20-268 WSAZ Pomeroy, Ohio, Chase Electric Shop 50-258 WSB Atlanta, Ga., Atlanta Journal 500-429 WSL Utica, N. Y., J. & M. Electric Co. 100-273 WSOE Milwaukee, Wis., School of Engineering of Milwaukee 100-246 WSW Birmingham, Ala.. Alabama Power Co. 500-360 \VTAB Fall River, Mass., Fall River Daily Herald Publishing Co. 100-266 WTAC Johnstown, Pa., Penn. Traffic Co. 150-275 WTAF New Orleans, La., Louis J Gallo 10-268 of national service WTAL Toledo, Ohio, Toledo Radio & The tools Electric Co. 10-252 WTAM Cleveland, Ohio, Willard Stor- The American people lead the world in the efficiency of industry. age Battery Co. 1000-390 WTAP Cambridge, Ill., Cambridge Ra- Who can say what part of their success is due to the superior dio & Electric Co 50-242 WTAQ Osseo, Wis., S. H. Van Gor- implements they use.. This much we know. They have the world's den & Son 100-254 1VTAR Norfolk, Va., Reliance Elec- best telephone system as an instrument of communication, and they tric Co. 100-280 use it without parallel among the races of the earth. To this end 1VTAS Elgin, Ill. (near), Charles E Erbstein 500-286 our telephone service must be equipped with proper tools. WTAT Boston, Mass. (portable), Edi- son Electric Illuminating The tools of management. Bell System executives, rising from Co. 100-244 WTAU Tecumseh, Nebr., Ruegg Bat- the ranks of those who know telephony, must share our respon- tery & Electric Co 10-242 1VTAW College Station, Tex., Agricul- sibility to the public, most of whom are telephone users, share- tural & Mechanical College of Texas - 250-280 holders or workers. 1VTAX Streator, Ill., Williams Hard- ware Co. 50-231 The tools of service. The national, two -billion -dollar Bell WTAY Oak Park, Ill., Oak Leaves be Broadcasting Station 500-283 System, handling fifty-eight million telephone calls a day, must 1VTAZ Lambertville, N. J., Thomas J enlarged and extended while in use. McGuire 15-261 11'TG Manhattan, Kans.. Kansas State of forecast. We must continue to know the rapid Agricultural College 50-273 The tools WWAD Philadelphia. Pa., Wright & and complex growth of communities and make provision in Wright, Inc. 100-360 tV\\ AE Joliet, Ill., Lawrence J. Crow- advance, so that the telephone will be ready when needed. ley (Alamo Ball Room) 500-242 1V1VAO Houghton, Mich., Michigan The tools of supply. The Western Electric Company, our College of Mines 250-244 W\VI Dearborn, Mich., Ford Motor manufacturing and purchasing department, its factories manned by Co. 250-273 assures extension facilities need never WWJ Detroit. Mich., Detroit News 500-517 40,000 workers, us that of WWL New Orleans, La., Loyola Uni- be interrupted. versity 5-280 We must have the best tools of finance, of invention, of every- RadIl© Lock SwIlect~h thing else, in order to continue serving the American people. . AMERICAN TELEPHONE AND TELEGRAPH COMPANY 51 AND ASSOCIATED COMPANIES But 8 BELL SYSTEM trJ°atria cur One Policy, One System, Universal Service MúsittessOiI$1 ckejuvenatión by the ng. WITH AN ACCREDITED SCHOOL I thor, W.J.Ftelding. All the facts about the miracles of 25c science in extend- ing the span of life; stopping old Arll Ozne age, rolling back the years to youthful physical and mental activity. A Completett Conservatory Course Wonderful home study manic lessons under BBMally great American and European teachers. LIMITED EDITION Endorsed by Paderewski Master teachers guide and coach Vest pocket size, flexible, real leather binding; you. Lessons a marvel of simplicity and completeness. an attractive gift volume opening op new life vistas; Write telling us course explaining impartially and fully what gland trannplant- Any Instrument you are interested io- ationdoes. Interests both men and women. Tells all Piano, Harmony,Voiee, Public School Music, Violin, Cornet you want to know about this fascinating and vital Mandolin. Guitar, Banjo, or Reed Organ-and we will send subject. The edition is limited-send 25 cents today OUT Free Catalog with details of course you want. Send now. in coin or stamps for prepaid copy. UNIVERSITY EXTENSION CONSERVATORY BRINKLEY 89 Siegel -Myer. Bldg. Chicago, Illinois PRESS, Dept. 2 Milford, Kans. This key switch will enable the owner of a radio set to protect his tubes and batteries Insure against theft or tampering with. The key can your copy reaching you each month. Subscribe to Science & Invention-$2.50 a year. be carried on key chain. One hole mount. Experimenter Publishing Co., 53 Park Place, N. Y. C. 1048 Science and Invention for February, 1925 npnmmnn ummm ntmunumanmmmmnmunmmmmnmmmmmnmmmmmnnnuummnnm minn i The goIlt7l1I(1, ewlh By JOHN MARTIN LEAHY (Continued from page 987) Vt's as ,nm.,,,,,,,,,,,,,,,,,,,,,,,,, a1m.,1e1,,..,,,a ,,,,,, n TO taro, to hear the rest of your story. Did MAKE you find anything else at that cave or in it?" "We did, in it, as you shall soon see. MUSIC. -and FRIENDS "We had come prepared (so I thought) to explore it, and at least we started in. THE `With a For the first few yards, the roof was so LOG BOOK low that we could not go upright. Then You've Always Wanted suddenly the walls drew apart and the THE RADIO BROADCAST LISTENER'S roof went sloping up to form a great BOOK OF INFORMATION AND LOG REC- vault. There was now no ice or ORD Is not -only a complete. practical book of underfoot those essential Radio facts that everyone as-ho anywhere. The place grew larger and larger mans a radio should know. but It is also a handy log record for those who want to keep a as we advanced until at last, standing in record of the stations Utey receive. SAXOPHONE the middle we barely make The book is enclosed In a handsome two-color point, could out cover, bound In Loose-leaf fashion, so that new Thousands of men the wall on either side. It was a strange, Pages can be Inserted If necessary. It contains 80 pages, each one containing Information more and women, of all weird scene, and it gave a man some solemn valuable than the last. ' ages, have found a thoughts to be entering this place which The following Is a brief summary of the In- sweet -toned Bues- formation contained in this book: human foot had never trod for so many Information for the Broadcast Listener: s f char Saxdphone an thousands of centuries. Vacuum Trbe Table: Meter wave lengths: infallible key to so- Radio Batteries: Wireless emit chart: "I was carrying the light, and I had Station Log Chart: cial popularity. stopped and raised it high above my head Complete List of Broadcast Stations of the ''For home United States. giving Power, wave length. and enter-- in order to get a good look roundabout Time of Operatic° earh City of the week. tainment, for when a sharp exclamation broké from Log Sheets for tabulating the dial settings church, school or of tho stations you receive on your radio, 6 Hampden. I looked, and I think that I SOLD BY ALL RADIO AND NEWS - - lodge affairs, the exclaimed; too. At any rate, I know I DEALERS y e4 Saxophone is the most popular started and a strange feeling came over me. and There, off to the right and some distance adaptable ahead, were two burning eyes, gleaming in instrument. Postage Paid Saxophone players the darkness with a greenish, hellish fire. "Even as my look fell upon them, their ' enjoy, - also, many r dull fire faded; then suddenly had r s opportunities of they earning money. vanished. Published by light I' said Hampden. 'Raise the r = "'The THE E. I. COMPANY light again l' "I did so, and there were the two eyes The Consrad Company burning once more. Sole Distributors "Hampden laughed. 233 Fulton St. New York, N.Y. "'Only the light shining on patches of -y7,r aS F Yn t1^ mineral.' g 1v "'Of course,' I said, moving towards i1 _r TO PLAY them. 'At first I can R - - thought-but there ' : - be no live thing in this place.' ;. "'Hardly,' Hampden laughed. 1. and tó. PAY - "We had gone some distance when I =_.... stopped again. 12 For a "We had better be careful,' I told him. 2. Volts "I pointed back towards the entrance, or SolidCella ^ c°a.b.be Sehrzy in that direction in which I thought the entrance ought to be, for we were now encompassed by pitchy darkness. ' ' SPECIAL c?rue Gone Saxophone "'We don't want to get lost in this hole.' .. INTRODUCTORY PRICE "Hampden treated this suggestion lightly. For a limited time only, and to introduce this With the aid of the first three new and superior Storage "B" Radio Battery to lessons, which are sent free "'Not much danger of that,' he told me. (upon request) with each the Public, we are selling it for 53.541. Regular new Saxophone, the scale "But I was not so confident on that score. Retail Price is55.5O. You save $2.00 by ordering can be mastered in an hour; "'See; I remarked, 'how the things send NOW. A finer battery cannot be built than the in a few weeks you can be arms in all directions.' playing popular music. You out World Storage "B" Battery a "Some of these were so large that I didn't (12 CELLS -24 VOLTS) can even take a place in To ten trillion homes with Radio Sets d to reunite.. mil- band or orchestra within 90 know whether we were following the main lion, of prospective bucen -thin Wu"W Sterner ' II bat- you so desire. lm ane,.brinesretery lnew battery economy perform- days, if cavern or not. Hampden, though, said that ance. atten th tp rrlel in fewand for end ear, be eerharaed of a negligiblee coat. there was no ground for uneasiness, and so And cots zure $2.00 by ordering non. Free Trial - ' we went on, slowly but steadily, deeper A SuperiorBattery só á I:b2 é'ase Easy Payments deeper into this place. Ilas heavy duty 2 143 In. s I In. s 1-4 In. plates d plenty of and strange and awful id circulation. Extra heavy glaze jar. allow ready ob.ervx. You Bues- lion of charge and revert leakage and seepage of current. may order any "The temperature of the cavern had risen It holds eh F while Idle. ateonstantvoltage. cher Saxophone, Cornet., You in find this battery a boon to long dlstanre reception. Trombone or any This beautiful book in a remarkable manner, how much we had It does away u Ith a great many foisea so often blamed on Trumpet, static ' Mail your order today. other Band or Orchestra In- shows how easy it is no means of knowing, for we had no ther- strument and try it six days to learn to play a mometer with us. Easy Buescher. In it you SEND NO MONEY in your own home. Just elate number of bntterlen wanted and we will .hip der terms of payment may be will find the first "I clearly perceived that a thorough ex- = order In ra0gg0ived. EXTRA OFFER: 4 hotteriea In merles 196 lesson chart. ppeelrrintá,uet arranged. Mention the in- It ploration of this great cavern was, at the for cash Í full withrordr.nScud yamrord i' strument interested in and shows all the differ- not NOW and save 12.00. a complete catalog will he ent models and tells present time, simply impossible; we had WORLD BATTERY COMPANY mailed to you free of charge. what each is used for. come prepared for that. And what would Prober, of the/mnu. World Radia 'A' Storage Battery a thorough exploration bring to light? A 1219 S. Wabash Ave., Dept. 83 Chicago, Ill.. BUESCHER BAND INSTRUMENT CO. man could even imagine that. The BY ORDERING NOW!' in Band and Orchestra Instruments not SAVE $2.00 Everything had so many theories and 7,17 Buescher Block Elkhart, Ind. Antarctic turned ~Mai «WIZ beliefs upside 'down and inside out * that Buescher Band Instrument Co. of the sea -water is all the 717 Buescher Block, Elkhart, Ind. I ' "The temperature Without obligation to me send year round several degrees lower than the freezing Gentlemen: I of yet the of animal life I your beautiful book "The Story of the Saxo- 1 point fresh water, growth phone** described above. Check here is so vigorous that at moderate depths the entire bottom is covered and hidden under a dense carpet if ou prefer literature describing other band I below. of rooted animals and among these hunt and grub You've beardi 1 or orchestra2Z-111 instruments, check your neighbor praise this Cornet Trumpet Trombone Tuba I great -numbers of active and predaceous fish and wonderful weekly magazine other locomotive animals. And all the time the that 3 million people read. Unbias- Any Other temperature of their bodies is just about that of the ed digest of national and world affairs. IMentionWrite plainly, Name, Address, Town and I water in which they live; that is to say, they are Chock full of the kind of reading you want Sci- State in Margin Below ence. politics, travel. fun. question bog, books, health, home, radio below freezing point. a temperature which has been -entertainment and Instruction for all, Send 15c (coin «stamps) today for thin bit 13 supposed to be fatal to all life."-Antarctic Days, paper on Mel weeks. or $1 for 1 year(S2 issues). Murray and Marston. PATHFINDER. 566 Langdon Sta., Washington, D. C. Science and Invention for February, 1925 1049 there was no telling what might be found here. "Certainly I never imagined anything so strange as what we did find. "The credit goes to Hampden, poor fel- Cartooning low. For I had come to a stop, my mind made up to turn back at that point. "'Just five hundred feet more,' said Hampden. i 'Not another inch,' I told him. at Home "But Hampden was a persistent fellow, and the result was that he got his five hundred feet. Earn One hundred and seventy paces,' said I. $100 a Week 'Unless we find something then, not a foot In This Fascinating Business farther. This place is like an oven.' "'One hundred and seventy,' said Hamp- C---ASEI in on the amazing ever-increasing popu- den. 'And here's the first.' I4 larity of cartoons! Thousands of cartoonists "I never saw longer paces in all my life. are needed to draw the vast number of political, I believe Hampden's legs must have been religious, international, seasonal and human -interest made of rubber. cartoons. There is a crying demand too for men "At last came the hundred -and -seventieth able to produce humorous cartoons, comic strips stride-I believe Hampden had managed to and sport cartoons. Advertising and animated car- make it eight hundred feet-and there we tooning ofler two wonderful new and almost un- halted. touched fields. Never before have the opportuni- 'Well,' I queried, 'satisfied now? Here ties in cartooning been so many or so varied. we are, and we have found nothing.' Never have cartoonists had such a wonderful chance "Hampden did not answer. I found his to make big money. Now indeed is the time to study eyes fixed on a point ahead and at some cartooning! distance above the cavern floor. I looked, too. I could see nothing but a black mass of New Methods Make Cartooning wall, but that was because a moment before Easy to Learn the light had shone in my eyes. "'Oh, Lord,' exclaimed Hampden, 'look at Regardless of how little advance through every ability you in branch that !' have of cartooning un- "A form shape up there on drawing, you can now til almost before you took that easily qualify black mass of wall-a figure vague, mon- for this at- realize it you are draw- horrible. tractive highly -paid bus- ing cartoons that SELL. strous, iness. "For some moments we stood star- Through a won- Many of our students there derful new method you ing. The light that to it was have sold enough work struggled can learn right at home while so feeble, however, we not be studying to pay that could in time. sure just what that thing was which we yáur spare for the course many saw. Learning t h is way is times over. more than it is Just "We moved slowly on towards it. easy- think of earning actually fascinating as a a splendid salary for " 'N. bat !' I exclaimed. game. such pleasant work. I' were Suc- "'No said Hampden, whose eyes First you learn the cessful better than mine. 'A harpy!' cartoonists earn important fundamental from $3,000 e "I fetched up in my tracks, and a shiver to o v r principles of cartoon - $100,000 a year. Yet went through me. making. Then you learn enough "'Again!' Hampden cried. cartoonists can- the little secrets of orig- not be found to meet the "'I wonder why a harpy,' I said. 'That inating ideas of action, tremendous demand. thing at first gave 'me the creeps.' exaggeration a n d ex- Right now there is a "A few moments, and we were within five pression-the little tricks wonderful opportunity or six yards of the wall. There we halted which make cartooning for you in fast - and stood gazing up at the sculptured mon- this easy to those who know g r o w i n g uncrowded ster. The figure, cut out of the living rock, them. Step by step you field. was a colossal one, being thirty feet in height and fully fifty in width. It was for FREE BOOK perched upon a heap of (sculptured) human Send Find out more about the wonderful skulls, the wings were outspread as though WASHINGTON SCHOOL OF CARTOONING it us, opportunities open to you in this at- was 'about to launch itself down upon tractive field. Learn more about this Room 262C, 1113 -15th St., N.W., Washington, D. C. and the expression of the face (a face of easy home -study method of learning car- send me without obligation your illustrated striking but repellant beauty) was fierce tooning. A handsome booklet has just Please book- been prepared which is crammed full of let on cartooning. and terrible beyond all description. interesting information about cartoon- "What was that? I blinked and looked ing, and describes in detail this remark- Name again. That carven horror up there above able method. It will be sent to you (Print Name Plainly) hart held we liad seen without cost, without obligation. Mail our look; nothing coupon for it TODAY! Andress else. But now I saw it. "There, right before our eyes, right under Washington School of Cartooning City State that careen monster, was-a door !" Room 262C 1113 -15th St., N. W., Washington, D. C. If under 16. years, please give age CHAPTER X\rI DEATH TAKES HIM "As we moved toward it, Hampden said: "'I see now what that harpy was for.' he T7raff1c Cop "I stopped and looked at him. No More Pumping ' Fir FEttBFJJD "'What was it for?' G oftheAdd a Ferbend Wage o- - "'To warn people to keep away -4o keep Tnpto your Radio Set out.' Up Tires ¡-'p and Poi ice" yourrecep- tion. Regulate traffic. , IIüalmljm I laughed. An air -tight valve tap which prevents all loss of air t Guaranteed to lane out 'hI iAPr in tires has been put on the market by F. C. Hughes. any interfering station. MF,:,:20.- ....III?? "'It probably worked in those old super- With this valve cap one (libation lasts the life of the Widely imitated bat stitious days; but it will take more than tire and doubles tire mileage. Tested and approved never equalled. The by leading automobile manufacturers. We furnish proof original and only sae- 8 that harpy up there, horrible though it is, of tests. Retail price $1.4 for set of five. Great ceasful WAVE TRAP. M a I demand. Wonderful opportunity for agents. write at Now in its third year. to keep me out.' Sent Postpaid upon re- I "'I think, though,' said Hampden, 'that ceipt of $9.50 or C. O. D. 1; C. HUGHES, 2512 W. Monroe St., Chicago, Ill. plus postage. Send for Free Booklet t the door will.' FERBEND ELECTRIC CO. l d 4i°'r "And it did. The entrance we found 71 E. so. water St. - Chicago , about four feet ,in width by seven in height and closed by a mass of solid rock. That this stone was a door and not a sealing slab, Insure your copy reaching you each month. Subscribe to Science and Inven- we both believed. But how did it work? tlon-$2.50 a year. Experimenter Publishing Co., 53 Park Place, N. Y. C. 1050 Science and Invention for February, 1925 We pushed and shoved and threw ourselves against it, but it never budged. "'A man might as well try to move Mount Rainier,' Hampden said. "'And no doubt,' I remarked, 'a fellow could open it with a push of his little finger fl"in 0n -if he only knew the secret.' "'Of course,' said Hampden, 'but we don't know it.' "'We might find the secret.' - "We made a long and careful search all around, but at last we had to give it up , , 1 in despair. "'What on earth,' Hampden said, 'is on the other side of that door?' . "That is a question I have asked myself a times since. What has thousand secret that Jones is Men Needed in harpy been guarding there in that awful loñehamr the many D ho ,,,r and en- darkness through all those ages. What will dorsedone the Conn that man see who at last moves the stone saxophone. Electricity slab and enters the passage? The answer I shall never know. But I believe, Mr. NO PROFESSION offers greater opportunity Isham Jones, thefamdussolois and orchestra leader, he. Frontenac, that on a day you will know it. made a fortune'with his to -day than Electricity. Salaries of $12 to Conn axophone. You can learn is found, and to play a Conn quickly and e sily. Then great oppor- $30 á day are not uncommon and the opportunity "And that what we we found nothing more, there in Sleeping tunities for pleasure and profi are open to you. for advancement is unlimited. Conn saxophones, used by the most famous stars, rrc- As Forrest Crissey said recently in The Satur- Beauty's Cavern. ognlzed as supreme in tone, tune and easy playing "Nothing daunted by this close call, for qualities, may be had on Free Trial; Easy Payment plan. day Evening Post-"The demand for electrical Write for catalog and details. work' is increasing immensely and electrical con - it really was that, Hampden was anxious to :tractors assert that the supply of electrical workers go in again; but I wouldn't hear of it. C. O. CONN, Ltd., 256 Conn Bldg., Elkhart, Ind,, "cannot overtake the demand for several years." "'Why,' Hampden cried, 'there is no tell- Now is the time to prepare for a good position ing what else there is in that cave!' in this profitable, interesting profession. You can "'That is very true,' I told him; 'but study right at home in spare time through the what we want to' do is not to run any BAND International Correspondence Schools-just as so risks but to get our story to the world.' 1N STRUM ENTS many other men have done. The I. C. S. Elec- l.1413 1.111KTVIISAII trical Courses have been endorsed by Thomas A. "Hampden was terribly put out about it ; Edison and Charles P. Steinmetz-the late elec- but I remained firm and adamant. BLANK CARTRIDGE PISTOL trical wizard of the General Electric Co. "We were nearing Depot Number One f'rotectwn eosin[ Burotdr., Tromps, &Dog. Just mark and mail the coupon printed below when it happened. The sky was dark and ár- PRICES and full information about Electrical Engineering, gloomy, but Hampden and I were in gay 50c. Electric Lighting, Electric Wiring, Electric Rail- spirits. Certainly the prospect seemed a - íf ways, Radio or any other work of your choice will bright one. A few days more, and we :$100 come to you by return mail. would be back at Summer Haven. And POST- PAID the Coupon To -day then it came, like a bolt from out the blue, Mail Well masa and et. and I was left all alone, a man shaken active; modelled en ,TCAn OJT HCnt .teat chest Revolter: INTERNATIONAL and wretched. appearance alone 13 CORRESPONDENCE SCHOOLS saoagh Boa 19 to atarea117C; (/ 6 b-1), Scranton, Penna. "Hampden was leading. The surface oat. Wh loaded ltnu7 Explain, without obligating me. how 1 can qualify for .tie CIrerq unreal the position, or in the subject. before which I mark X. seemed almost level and firm as a floor, and Cut.[BlankCartridges die ttt ~aad-- ] lard every. ELECTRICAL ENGINEER CHEMICAL ENGINEER we were swinging along at a smart pace. here Price Set. er euallty 00 l t -I CIecVICIan rnarmacy paid. blank Cartridge, by eiDrra., SOt DaDei 100. V. Electric Wiring SALESMANSHIP My look was not upon him at the instant JOHNSON SMITH & CO. Dept. 289 Racine, Wla, oElectric Lighting ADVERTISING MAN Electric Car Running Window Trimmer it happened. There was a cry, and I looked Heavy Electric Traction Show Card and Sirs l alnt'a up and saw Hampden make Electrical Draftsman RAILROADPOSITION.4 a wild effort Electric tlarhine Oeda.er ILLUSTRATOR to turn and save himself, the rear end of 'I GuaranteeYou Can PlayAny Telegraph DESIGNER Expert DCSINESS SIANAGEMENT the sled tip up, and the sled slip forward Practical' Telephony Private Secretary String Instrument in 5111011.010.1 I. ENRINEE..11 and vanish, dragging the dogs down after 11 Minute Mechanical Draftsman Business Correspondent BOOKKEEPER it. For an instant I thought that Hamp- Most Machine Shop Practice Stenographer and Teal.r remarkable motile Invention of the ceo- Toolmaker Cert. Pub. Accountant den had gone down, too. But no, there tury. Any novice can now play any string Gas Engineer Traffic instrument-INSTANTLY! A child can CIVIL Management he was clinging to the edge lay withoearut ENGINEER Commercial Law of the crevasse hesitati,n No notes to N ' `, la Surveying and Mapping GOOD ENGLISH Iearn-no - C Mining Engineer and crying wildly for help. for music 20- STATIONARY ENGINEER needed. ARCHITECT CIVIL SERVICE "I rushed forward. I saw with horror j VALUE Architectural Draftsman Rdlway Mail Clerk eeOpt'foe Architects' Blue Print. Textile 0 Sept. that Hampden was slipping, that he was " FREE! I'LOM IlING AND HEATING AGRICULTURE 0o the Beautiful Instrument eft sinking lower and lower. The snow and i an with each color number Sheet Metal Worker realleyltelsing Spanish market. ice that he was clinging ran co- i tour.e,R,eh,meuowtone. Navigator Automobiles 10 RADIO to were giving t etin c' MoneyBackeuarantee 11 9. / way. Would the edge hold till I reached You r money back i (i t falls. ppb: r Oct full details and Free in- Name him? I got to within feet P aneeel I etrameet offer. Write Todyl 4-30-24 thirty of him, narealous"1i, Present Business and then it broke. One loud, terrible cry chool of Muslo knownimu ci.s.. 238 Yemeni 511 teDLder SU -28ía, island IV Occupation Address was heard, then utter silence-or, if any Street and No other sound came up from, that frightful place, I was not aware of it in the horror HERE S MORE: City State of that moment. m0NEYfor YOU Canadians may send this coupon to International Corre- "I went to the edge and looked 150 HOME spondence Schools Canadian, Limited, Montreal. down- STUDY BOOKS Canada into an abyss that seemed fathomless, Each of these sure pay -raising self-help from books Is a complete course of instruction. which not the faintest sound came up. They cover Electricity, Automobile. Ma- chine Shop, Carpentry. Painting, Engineer- "I cried out Hampdeñ s name and cried ing. Railroading, and twenty other trades. it again and again, but never any answer Full catalogue FREE. A postcard brings yours. came-never the faintest sound. F. J. DRAKE & CO., PUBLISHERS ' I n09 Mlabinsn Avenue Chica2e RADIO "How long I stayed there. I do not know. It is an awful feeling to have a man LATEST WHOLESALE FR' ' . CATAL%G snatched from you like that-a feeling that I hope to God neither of you will ever RADIO CATALOG Sent YouEvery o,;:h know. Simply send name ALL the latest im- TODAY for big proved apparatus At last, however, I left that cursed spot, is REE 48 - page catalog listed in our monthly bul- and I did not make camp until I had reached letin: "The American the depot, nearly twenty miles distant from of latest radio goods at Wholesale. Radio Transmitter," 11 Live dealers and agents wanted. it's new we have the scene of the tragedy. it. STANDARD_ RADIO CO.. 112 East 1311 !Kansas City. Moe Lowest "And that is Prices in U.S. why I have no photographs You can be quickly cured, you Our prices to deniers are the of the Gardens of Paradise if lowest in the United States. or of Sleeping A I I nationally advertised Beauty to show you. All had been on 'mood. ., discounts that maee YOU real money. D..l-re, Hamnden's sled, together with that piece tod.yoforn loten tno STAMMER º .7Z,"1111 bulleno,mphowlena 76 pa. lonallr adrertleed Metelu lines end a,hóo item.. which we had broken off the sculptured Send in rents for 209 -nace honk on Stammering and ItlEtl:p liaDa M10. CD. ere. Si. and how I NIA Dept. F, .anus Cllr, Mo. ' pillar, and now Rtntterine, "Its Cause Cure.' It tells all were gone. cured myself after stammering 20 yrs. B. N. Bogus. "There is little more to tell. It was awful 8113 Bogue Bldg., 1147 N. Ill. St., Indianapolis Science and Invention tor February, 1925 1051 making my way through that terrible lone- liness, but there was one consolation: I would soon be home. "It would be impossible to describe the joy that I felt when at last I gained the Earn5O to 2OO aWeek summit of the ridge to the north of Mount Theodore Roosevelt and Mount Woodrow Wilson and looked down on Summer Haven. "There, far away, was the hut and the a Multnomah moored in her little cove. For in RADIO some time I stood there looking upon that You can! Hundreds of ambitious men are already earning tbou_ } strange and familiar scene. Everything was sands of dollars in this wonderful new industry-you, too, car get so peaceful, so dreamy and lovely. It was your share. Mail coupon below for Free Book which descdbes fully the amazing money -making opportunities in Radio and a joy to see the old place again, and yet I tells how YOU can earn from $5000 to over 510,000 a !ear. knew sorrow too as I stood there and The astounding growth of Radio has created thousand; of gazed upon it, for, of the brave and loyal big money opportunities. Millions of dollars were spent during men who had gone with me into the Un- the past year on Rodio, and thousands of young seen are known, not a one was with me now. needed right now to meet the ever-increasing demand of twrk. Men are needed to build, sell and install Radio sets- "Many thoughts came to me as I stood to design, test, repair-as radio engineers and execu- there and not a few questions that I wished tives-as operators at land stations and on ships travel- could be answered. Well, some of them ing the world over-as operators at the hundreds of broadcasting stations. And these are just a few of the would be answered when I reached the wonderful opportunities. hut. So I spoke to the dogs, and once more we were in motion. Easy to Learn Radio at Home "I liad got within a quarter of a mile in Spare Time of the hut before they discovered me. There No matter if you know nothing about Radio now, you can quickly become a radio expert, by was a great waving of arms and some cheer- our marvelous new method of practical instruc- la' ing, and they started towards me. tion-instruction which includes all the mate. - "'Where arc the others?' was the first rial for building the latest tip -to -date radio asked. apparatus. question they Scores of young men who have taken our "I started to tell them. And now I saw course are already earning from $75 to $200 a e ' ^f+ for the first time that thing which was to week. Merle \\ etzel of Chicago Heights, Ill., embitter the rest of my days. Never could advanced front lineman to Radio Engineer, increasing his salary 100% even while taking our I forget that look which came to their faces course! Emmet Welch, right after finishing his when I mentioned the palm -trees. I had, training, started earning $300 a month and ex- wondered how my story penses. Another graduate is now an operator of of course, often a broadcasting station-P\VX of Havana, be received. I had never blinked the Cuba, and would earns $250 a month. Still another graduate. only 16 fact that there would be difficulties; but years old. is averaging $70 a week in a radio store. Radio now, for the first time, I fully saw what Schools-established in 1914. Our course is Wonderful Opportunities an absolutely complete one which qualifies for a really awaited me. The realization came government first-class Hardly a week goes by commercial license. It gets with something like a shock. I had counted without our receiving ur- yon the bigger paying jobs in Radio. gent calls for our graduates. "\Ve need the on the photographs removing any doubt that of services a competent Radio Engineer." "\Ve want men Send for FREE might linger. But there was not a single with executive abili- RADIO BOOK had been lost ty in addition to ra- Learn store about this tremendous new field and photograph to show them; all its remarkable opportunities. with poor Hampden. dio knowledge to be- Learn how you can Pay Increases come our local man- quickly become a radio expert and make big money "Not a word did I say about Sleeping Over $100 a Month agers." "We require in Radio. Beauty, or the cave, or that mysterious door the services of sev- \Ve have just prepared a new 32 -page booklet which I am aver- eral resident gives a thorough outline of the field of Radio-and over which that carven horror holds its aging any - demon- describes where from strators"-these are our amazing practical training in detail. eternal vigil; but I did try to give them a $75 to $150 just a few small in- This Free Book, "Rich plain, accurate, convincing account of all the - 1 month dications of the great Rewards in Radio," will moro than I variety be sent to you without t rest. It was not long, though, before I saw w a a making of opportun- ities the slightest obligation. was useless. Instead enroll. open to our Mail coupon clearly that the effort / Ing ith yonu. graduates. for it now/ For a short time RICH of overcoming their incredulity, I was, it was bbaD / beforew,I would ot RFW consider HO - Take advantage of we are offering a re- very clear, only strengthening their convic- 000 too much our practical train- duced rate to those IN tion-formed at the very first-that what I for the course. ing and the unusual who enroll at once. had gone through had turned my brain. (Signed) A. N. Long. conditions in Radio Act promptly and Greensburg, Pa - to step into a big save money. "At length they began to humor me. That paying position in this much and the bitterest of all, and 1 wonderful new was too field. Radio offers National gave up in anger and fierce despair. Doubles Salary you more money know, you than you Radio Institute "The rest you or can easily I can very probably imagine it. easily make ever dreamed possi Dept. 14DB double t h e ble-fascinating easy Washington, "And so now my story is done. What is amount of work-a chance to D. C. to follow, no living man can say; and I money n o w travel and see the than before world if you care to NATIONAL RADIO INSTITUTE shall never know it. But I do know that I enrolled'. h. Dept 14-DB, Washington, D. C. with you. t5, or to take any one you will see wonderful things, and terrible Your course Please send mo %about the slightest obligation your Free of the many radio Book. "Rich likelihood, has benefited positions all Rewards In Radio" and full details of your ones too in all before the word m e apnrozi- around special Free Employment Service. Please write plainly. finis is written. mutely 8:1,000 you at home. And over and above what 1 would Radio offers you a Name Age "I pray God to watch over you, Mr. have Gamed had I not taken glorious future! it. Frontenac, and bring you safe through it (Signed) T. Winder. The N-'tional Ra- Address all I" Grand Junction. Colo. dio Institute Is one CHAPTER XVII of America's Pioneer City State THE "MULTNOMAH" SAILS "Well, Bond," said Darwin. Frontenac as we seated ourselves after seeing Captain FORDS*Start Easy at Zero GOLD PLATED AERIAL Livingstone into his car, "what do you think Nearly WORKS WONDERS of it?" double mileage Amazing new antenna The Goldenrod works wonders with 5OZ More any set. Clearer reception; moro stations; greater volume; "No man ever told a stranger story-if, The AIR Powerry no "fading"; won't corrode, lasts lifetime. Used by Gov- FRICTION its the ONLY Car- ernment, Ocean Liners, Broadcasting Stations. that is, what he told us is true." buretor which chaug,-e ordinary gasoline into powerful, superheated DRY GAS. NOW EVERYONE "It is true, Bond." VAPOR which burns op el -an, present,. CAN HAVE IT carbon R011á Phosphor Bronze wire- (3 and nearly doubles power and heavily plated with 18 kt gold. "Do you mean to tell me you believe that Leave. unburned Gold antenna long known to be best, hut too costly. Now thru girl, incased in solid is to run down into crankcase, dietreyyllubrication and grind out Goldenrod methods of manufacture, every set user can have one. that ice-if there b aringa. Motors live two to three time. tion. Ford guaranteed as long with Air Fric- FR Illustrated folder giving complete details and proof of such a girl at all-is alive?" to make 34 miles to gallon- Other EE wonderful results from Goldenrod Aerial-"Best are in proportion. Try Air Friction 30 day. at our Be- "No." Money back if risk. cause It's Gold Plated." Write quirk cud soon get new joys you want it. Agents wanted. Write today. In radio reception! "Then why-?" AIR -FRICTION CARBURETOR COMPANY 1515 Raymond Building IMP RADIO CORPORATION "Just a moment." said Frontenac, uplift- Dayton, Ohio, U. S. A. Dent 104 ti East L1ke Street, CHICAGO ing a finger. "What I said was that I do not actually believe that she is alive. That. ADULTS! SEX KNOWLEDGE BOOKS BECOME A. LIGHTNING however, is not tantamount to saying that Instructive, authoritative, profusely il- TRICK CARTOONIST" lustrated In natural colors. etc. The worth -while sort. Con- Make I believe she is tains everything one should know money chalk talking. Send $1 for ,nappy dead. No man can say bout before and after mar- program of trick drawings. with riage to enjoy health and happiness, Lanee C.tsrng, Ion instructions by a whether she is or is not. What I do be - F. SMETANA & CO. professional cartoonist. Satisfaction guaranteed OWOSSO, MICR. Cireutar free. Balda Art Service, Dept. 4, Oshkosh, Wit. 1052 Science and Invention for February, 1925 IIrrrrrrr*rrzrrrii rtrrrirrrrrrrrnunrirrrrrrnrtrursrrrrzrryrrrtrTn m lieve is simply this: that it is very prob- able indeed that the poor thing is not dead." "And you believe that you can awake TheTypewriter of her ?" . _ - - "I have every reason to feel confident - a Thousand Uses ! that such will be the result-that is, sup- posing always that she be not dead." THE New Hammond will ex- "A fter all these thousands of years!" I press your thoughts in many exclaimed. "One hundred, two hundred. type sizes and styles-all instantly three hundred thousand years! But how do we know, after all, that she has been interchangeable on the. same there for so many ages, that she has been machine. lying there ever since. the Great Cold fell?" Languages of all nations are at "We don't /nun', it but I think we shall What Other Typewriter the command of the Hammond find Captain Livingstone's inferences fully user; two are in the machine at justified. We know that thousands upon Can Do These Things thousands of years have rolled over this old all times-changed by the twist globe of ours since the snow and ice gath- Variable spacing. of your thumb. ered about the Poles. N e know that the Interchangeable type styles. climate there was a warm one in Miocene 17 different sizes and styles print. Condensed writing in one-third of times; therefore the cold must have fallen in Over fifty different languages. the usual space is made possible the Pliocene. That it came suddenly, instanta- Automatic touch assuring uniform impression whether the key is through Hammond miniature neously, as the captain (with the great pressed lightly or heavily. type and variable spacing. Cuvier) believes it did, is a matter upon which one may be permitted to entertain some doubts. On the other hand, certain considerations incline me to the belief that THE NEW the captain may he right. But the point is simply this: Sleeping Beauty could not have lived there after the land was mantled amm loud in snow and ice; ergo she must have been TYPEWRITER there when that awful curse fell upon the Antarctic." VARIABLE SPACING s t CHANGEABLE TYPE "Unless," I proffered, "the Gardens of Paradise once extended much farther than is certain to fit your need. Write for new book- they do today and some of the survivors let describing how it accomplishes its wonders. of the awful cataclysm had sought a refuge there." Hammond Typewriter Corpn., 72 Brook Ave. at 132nd St., New York "I thought," said Frontenac, "that that ar.Tur rrmrrilrrniltrx IZZI7Ira arr to lit I, would be your suggestion. I think it un- likely, though, that such was actually the case. I incline to the belief that, instead of being much larger, the Gardens of Para- " dise were at one time even of less extent ;I1 E QUARTETTFZ+ than they are today. For the cold of the Antarctic, bitter though it is now, was once e far more terrible." "We must wait-wait until you awake the sleeper." '7 "Until I awake the sleeper I" he mur- mured. 7 He turned his face towards me, and { never shall I forget that look which I saw upon it. American --''Y' Legion of "Bond," said he, "I wonder, supposing that / Wisconsin I do awake wonder if she will 945'51 her-I thank ?''r¡ -Paul me for it or live to curse both me and Florin . Post No. 166 the hour." _ifrrasediv-,x_ I remained silent, wondering. f/ "But," he added. "we should regard the $aw Clob matter in its purely scientific aspect, and in Yourr Town then we find it one of extraordinary inter- Play a Saw est, to say nothing of its possibilities. Sen- With Our Free Course of Instruction You Can timent is all very well in its place-as are thorns and roses." ~It "Why the gloomy thoughts?" I queried. Play in 3 Days Now so suddenly look We -positively Guarantee that you can play our Musical Saw (using both bow "Why at the dark possi- Only and hammer)r) within three days by following our simple and emir Conroe of instruction. bilities? Remember, you may for " w ' e the rodent to play musical instrument ever invented. No knowl- awake edge of music or noto reading required. some man a sweetheart-perhaps, indeed, If you have heard our Musical Saw in Vaudeville,Vaudeville overthe Radio or from Victor Record 18767. Columbia Record 3757 or Vocation you are familiar your own fond lover." with tho sett, mellow tone. produced from our musical maws. - The "novelty" of producing such ul meek from now" makes Frontenac smiled at that, and then he thin instrument 'al IE l "on my program entertainment_ " in roar Lodger Legion poet or Cluh. A laughed a little. 1 Start A Saw Quartette .event m ,etiv this kind be ° the talk ofrt the `card yo "pep Into loutYour pennes. make it feat-Cent- "I always knew that'you were a poetical zero advertising card at your entertainments, Dartiea, etc. i ST son of a gun, Bond. where the ladies are M719 bW. Water St. but I dreamed had it Send No Money Pt. Atkteiitnson. Wit. concerned, never you yon momeentm so bad e Simply fill out the coupon and oil today. We send you Soft $ Free Mmcm lo aw. as that." the epeeist tempered. tenor Mole) Musical Saw. Soft etruetioD. 1 will deposit with pwtwn`111,,0.=11,27,1170,2,- Hammer and complete Course of Instruction C.O.D. 54.86 ylee pieta¢ . If not entirely natlefed "Well, now," I replied, "looking at the 54 85 plus the ,stage. Te, out the instrument for 1 will return the ehiDment within three day. , three days, if not aatiefed with the tone or its and ron will refund MY money. matter in a sober light, what is there so enaynese to play, return and we will refund your a money. terribly romantic, so terribly poetical, so $L SOLJUDGE. You be the one to Name.. furnish the big eurpriaetoMiARE at your nest Club awfully absurd in my suggestion? The girl or Lodge meeting. Then. tart a Trio Quartette. Complete information is young; she is (if the captain's eye is to on this aubiect will be mailed to you Address ... with the instrument. be trusted) a very lovely Sleeping Beauty MUSSEHL & WESTPHAL indeed; and do you think for a moment that The cost of our apeetal "Saw Bow" I. $2.25 extra, p FT. ATKINSON, WISCONSIN check here if you wick Row rent with instrument. there will be no lover?" "I think that the lover will come. Oh, I know that-just as well as I know that Insure your copy reaching you each month. Subscribe to Science & Inven- it won't be I." tion-$2.50 a year. Experimenter Publishing Co., 53 Park Place, N. Y. C. "Oh, indeed ! just wait till you awake e her, wait till you see her .a living, breath- Science and Invention for February, 1925 1033 ing woman in all the charm of her love- liness." He smiled a little but made no response to this. What he said was: "Do you know, Bond, what, in all the captain's strange story, gave me the great- est surprise?" "The palm -trees?" ''The palm -trees? Fiddlesticks! Coma again," said Frontenac. "And that reminds me: did you know that Nordenskjold thought he might find an oasis in the heart of Greenland?" "I didn't know that." "Well, he did." "Did any scientist ever look for icebergs in the Sahara? But to come back. The severed head of Wilkie-and the mark of that enormous claw?" "Once more," said Frontenac. "Sleeping Beauty herself ?" "Not even Sleeping Beauty herself." äumbloudS# "\Vhat a queer way you have of looking at things, Then it must have been that mysterious door there in the cavern?" Don't blame the circuit or your- efficient 5 and 3 tube sets at little "You're a mighty good guesser, Bond." self if "What on earth was it?" only noise comes from your cost; the Hilco Multiformer per- "His telling us that he had fallen in love loud speaker. Hilco apparatus fecting the Reflex and Neutrodyne with that girl !" makes the dumbest loud "A strange love certainly," I said. speaker when used as replacement coils. He was silent for some moments, then talk. asked: When you buy Hilco apparatus "Going to go with 'me to get Sleeping The Hilco Beauty, Bond?" Laboratories contain for improving your present receiv- "I must think the thing over." special equipment of marvelous er or the construction of a new one "Of course. But I fancy I know what accuracy for determining whether you your answer will be." are getting the latest in scien- "This thing you're entering upon," I re- new circuits and apparatus devel- tific radio apparatus that is dis- minded him, "isn t going to be a honey- oped by Hilco research moon." engineers tinctively different and superior in "I haven't forgotten that. A honeymoon will give maximum satisfaction. efficiency' and appearance. is only the end of a dream, but this-this," said Darwin Frontenac, "is the find of a Ever striving for perfection, Literature describing Hilco pro- century. And the captain got only a glimpse, Hilco so to speak. There is no telling what developed a new type of ducts free-Blue Prints of circuits other things may be down there." Fixed Condenser guaranteed ac- sent at actual mailing cost of 10c. "That is very true. I'm not particularly anxious, though, to get decapitated." curate within 5% of rating; the "The mystery." he smiled, "makes the ad- famous 7 -tube Super Hilco-Dyne venture-well, piquant." Kit "Piquant? Heaven help us!" enabling anyone to construct "Well, 'tis so," said Frontenac. "And the at a moderate cost, radio's most Ask Your Dealer risk gives it pep." superb receiver; about Hilco Products, especially "Pep? I think you'll call it something the Hilco Lo - else when that thing in the palm -trees starts Loss Tuned Radio Frequency Kit Super Hilco-Dyne Kit $30.00 work on your jugular." and the He smiled faintly, but he made no re- Hilcoflex Kit, containing Lo -Loss T.R.F. Hilco Kit 17.50 sponse; a silence ensued. essential parts for building really Hilcoflex Kit 8.50 Of course, he could get Sleeping Beauty without running that fearful risk; but I Hilco Multiformer 2.25 knew better than ever to make such a sug- Please Hilco Fixed Condensers. gestion to Darwin Frontenac Addres Dept. 16 Why is danger, mystery the fascinating Hilco Super Het replacement thing it so often is? I have often won- parts for perfecting Super Hets. dered about it but never have found any A.E.HIL MFG CO real explanation. It doesn't matter how Quanta Georgia WRITE FOR DESCRIPTIVE MATTER terrible, how horrible it may be, there arc km always men simply crazy to go. Its subtle, fierce power enshadows the fascination even of woman: sweethearts, wives are left be- hind, and with glad hearts the men go ' -- forth, in their ears (and hearts) the sweet, WANTED 1, terrible song of the siren. °e : 'wi \Vhy do they go? I wish I knew! RAILWAY POSTAL CLERKS j And I ought to 'know, too, for (though FRANKLIN INSTITUTE. there was neither sweetheart nor wife in ' Dept W181, Rochester, N. Y. my case) I am one of those fools myself! $1600 to $2300 Year ? Sirs: Send me without charge, (1) Sample TRAVEL-See your country o Railway Postal Clerk Examination coaching The next day Frontenac and I, accom- R. lessons; (2) Schedule showing places of coming MEN-BOYS, 18 UP U. S. Government examinations; (3) List of many panied by Captain Livingstone, went to see O Government Jobs now obtainable. the Multnouzah. It was about half past SHOULD MAIL COUPON IMMEDIATELY Steady work. No layoffs. Paid Vacations Name nine when we arrived at Pier R, on the Common Education Sufficient south side of which the famous ship was Address ' lying. A few moments, and we had issued from the warehouse and the whole of Monthly from- HS the 1300 PROFIT 8 Hr. Battery ehArtir vessel was in view. I say the whole of the Add big battery charging profits to your Income. Just $35 cash vessel, but this (with the usual point of puts this HB 8 -Hour Constant Potential Battery Charging in your outfit view in mind) is not shop--complete--all ready to set up and operate. Easy strictly correct, for terms on balance. This HB le the lowest -priced complete outfit the tide was low, and we on the market 90 days' triar on money were looking equipment -back guarantee. Ideal no: at the Multnomah but down upon for the small battery shoo. No experience needed to her Install or operate. RH Users clear $150 to $300 monthly profits. decks. Write for free bulletin No. 252. HOBART BROS. COMPANY And the first thing that struck me was Box S-2 Troy, Ohio I' Pays For Itself " Earns Bid Profits 1054 Science and Invention for February, 1925 that the Multnomah was one of the queer- est -looking tubs that I liad ever set eyes on. Yes, that is what site reminded me of at the first glance-a tub. This was due to her unusual beam-she was only three times as long as she was wide-and to her bow -like stern. The Multttotnah was not built oil the lines of a yacht but for service-the fierce buffets and dangers of the terrible t\ntarctic seas. A gangplank was out-up, rather-and Into the attic in a few minutes we were on the deck. There we met the first mate-Mr. Ben Rainier, a mail of powerful physique and a sW youngsters to -day ever saw a horsehair visage so grim that it would have been repel- lant but for the strange intellectual cast of ofa. They wouldn't know what to do with a some of the features. or coal -oil lamp. They "Well, Mr. Rainier," said the captain, "I fire taper, carpet stretcher, have good news for you: the expedition is couldn't braid rags into a rug, or wind yarn with- now a sure thing." "I am glad to hear that, Captain Living- out tangling. But they know the how and why stone," said the mate, not the slightest change of expression, however, on his face. "I felt of typewriters, phonographs, telephones, automo- all the time that those doctors-" "It isn't that," the captain told him. "The ; happens when a of the button miles what push doctors knew. I ant doomed. Mr. Fron- gives light, or a kodak's flash fixes their image on tenac takes command of the expedition. I go along, of course-until you clump me over paper. the side with a sack of coal at my feet." "This is sad news, Captain Livingstone," Their education is as modern as the advertise- said the mate, still not the faintest change on that strange visage. "This is indeed sad ments they see. They have no more use for the news. Perhaps, however, things are not so bad as they seem; perhaps, after all, those lamp and chimney of yesterday than you for the doctors-" The captain gave a melancholy wave of wick and tallow of the day before. the hand. "It wouldn't do me or anybody else any Advertisements induce such progress. They urge good to blink, Mr. Rainier," he said. "A help you man should never blink facts, no matter how wide use that means improvement. They disagreeable the facts may be. If he does, lift the out-of-date into the attic-rid you oí the he is liable to get a wallop right between the eyes daring one of the blinks." water buckets and soap kettles of slavedom. They "That is true." said Mr. Ben Rainier. "No, I have had my day; and, now that I bring late improvements within your reach. am finished, I am not going to shed any tears over my end. Instead of weeping over Read the advertisements regularly. Keep alert the inevitable, I thank God that my work- and work that I could never dream of doing to the new. myself-is to be carried on by Mr. Fron- tenac" The mate turned his impassive visage to- wards my companion. "This is sad news and glad news," he said. "The glad news is that our commander is to be Mr. Frontenac." For my part, I couldn't help wondering you never if the mate really was glad. Without advertising, would "\Ve of the Northwest." he added, "are know a product's worth until proud of you, Mr. Frontenac-proud of your fame and that we arc your neighbors, so you had bought it to speak." "Just wait till the expedition returns 1" said the captain. "Great though Mr. Fron- tenac's fame is now-well wait till then! Your pride will know no bounds. My one great regret in all this business is that I shall not be here to share that pride." Then it was, for the first time, that I thought I saw a change in that visage of Mr. Ben Rainier; I thought that a question- ing look came into those yellow eyes of his, but even of this I could not be sure. DeForert He remained thinking no doubt - HONEYCOMB COILS silent. that Liusus r4cg would explain. The Universal all -wave Pre the captain inductance. Back and What the captain said was: front panel mountings. "Well, gentlemen, I will show you over Send 25c for Super BeginmTed. FREE can penman ofr u os ho me dgng the ship." Het., R. F. and Honey- time. Write for my FREE ROOK, "Now comb Coil Circuits and io Become Good Penman." tteoown e The 1falhtonta/t was a three -masted fore - men. and tell. how others mastered penman- Complete Catalog. Olio by the Tamblyn System. Your u will and -after, with two square topsails on the elegantly wostaD on . if you enclose Chas. inc. etamD re%¡ Á,}áf ,t b pay postage. Write today for hook. foremast ; her length one hundred and thirty- . J J`1Yl)l Dept. 4. o.5 St. P.W.TAMBLYN, 424 BIdt.BIdf.,K City, U.S.A. . -line Buffalo. N. Y. two feet over all, on the water one hundred and fifteen. Her beam, for a vessel of that length, was a most unusual one, being The Midget no less than thirty-eight feet and ten inches. "Five -in -One" Slide Rule a combinationis Mannheim. Pol,met- She had a depth of eighteen and, when Go Into Business for Yourself tie. -Log. Bluer,. Add arid Sub. erect Slide Rol.. It will instantly add, heavily laden, a draught of fifteen feet and without storekeepers' troubles Dtraet,multipl, end divide any com- Make storekeepers' profits bination of whole number.. (ruction., a displacement of nine hundred tons. The or expenses. No investment necessary. We furnish mixed number..nd decimal.. Give. sail area was about two thousand three hun- everything and carry all stock for you. We have started every power, odeofaluminum . h square yards, and site had, hundreds of men who are nose making P4000 to 810.000 smile. on white celluloid. She 4 M. A p. dred and eight a year. We ran do the same for you. Write for facts proved and *dented by rolled., Brice power, a two hundred and with Inet,netion.. 81 60. Lew the, Co.* for auxiliary at once. Address Dept. 561, OOODWEAR Chicago. etra. Sent fl if desireCab twenty-five horse -power Diesel engine. By Inc., West Adams SL, at Peoria, Chicago. Mo.u. Free. GI SO i SLIDE CO.. Niles, Mich. means of this motor, the )1lnitnontah, when Science and Invention for February, 1925 1055 heavily laden, could move through the water at the rate of some five or six knots per hour. This was no great speed, truly, but Playa SAX! it was a great thing for all that. It is strange the way we sometimes arrive Have Fury_ at momentous decisions-some of the cir- Nothing will bring cumstances that influence us being so subtle as you so many ak. to baffle analysis. In my case, when I friends or make stepped onto the Multnomall's deck, I was, you so popu- as regards this strange quest, uncertainty lar as being itself. Long before we left the ship, how- able to play a ever, my mind was made up. I would go. saxophone. I would go and see Sleeping Beauty in her The newYork bed of ice, see that mysterious door over Saxophone is which the great harpy held guard and enter easier to finger, the wonderful, the awful Gardens of Para- easier to blow. dise. Make Why this sudden dissipation of all doubt DAYS and uncertainty? Why this sudden, irre- FREE vocable decision, the consequences of which Big Money RIAL no man could even imagine? I did not 1'; know. I am not sure that I know r With now. as a our free lessons you However. I said : can be playing popular nothing about this at the tunes time; indeed, it was not till the day = «;in a short time. You can get follow- this wonderful instrument, ing that I told Darwin Frontenac. with its He gripped my hand, and his gray eyes RadioEper! superb tone and per- gleamed in fect workmanship on six days' a way that thrilled me. . "I knew all the time, Bond, old tillicuni," Pay w but free trial in your own home. s3.0004410000 he said, "that you would I a year " ahfp Then if you decide to keep it you go! can't tell can take ten months to pay. Write you how glad I am to learn that at last Yes-$3,000 to $10,000 a year! These at once for free saxophone book- you know it yourself." are the opportunities. The chance of a let. Other York Band Instruments "When do we sent on the same easy terms. Free start?" lifetime. Investigate! Look into the literature upon request. "The captain tells me that we ought to amazing possibilities of Radio. Become get away within the month. The Multnomah the Radio expert in your neighborhood. J. W. YORK U SONS could sail before that, as soon as the freezer" The Radio Association of America now Dept. 1825.B Grand Rapids, Mick. -this was to be built in the fore-hold-"is makes it easy for you to train for a big done if it wasn't for the delayed arrival of job, or to go into business for yourself. . some of the supplies, due, of course, to the If you want to get away from poor pay EVERYTHING IN hitch in his plans." and jobs with no future, here's your RADIO "Well," I Standard Prices Shipping Prepaid said, "a week would give me big opportunity. - plenty of time to get my affairs straightened We want ambitious men ANY RECEIVING SET out." everywhere- ANY SET OF PARTS to learn Radio operation, construction, "A week ?" installation, repairing and selling. Be ANY ARTICLE OR PART Frontenac gave a sound like a groan. ANY HOOK-UP our representative in your neighborhood. "A month will be none too long for me." Find out how you can qualify in a few Give full details. Say exactly what you want. Swiftly now days followed on the heels We will send anything C. O. D. We are of short months, and receive our marvelous your servants. days. 1000 Mile Radio Outfit FREE as part of If you are not certain what you want, give full Great had been the interest excited by your training. details and results you wish and we will send Frontenac's discovery ; and, when the big the cheapest part, set of parts or receiving set for best results. headlines informed the world that he wat Prices lowest. No order too small or too large. to head an expedition to the Antarctic, that Train at Home- MAIL ORDER ONLY interest became a very great interest indeed. In ALL RADIO And, in addition to its enhancement, there Three Months was that element of mystery about the whole Find out how, in your spare time at home, by 417 North Clark St., Chicago, Ill. mail, without giving up your present position or enterprise. losing a dollar of pay, you can become a Radio What had Captain Stanley Livingstone told Ezpert in a few short months. No previous ex- Darwin Frontenac? That was perience necessary. The possibilities for big the question salaries or to go in for yourself are unlimited. In which was being asked everywhere. Of no other line have ambitious, wide-awake men the MECHANICS' course, but three' men knew-thé captain. chance that Radio offers. Yon can now train Frontenac and myself. under one of America's leading Radio authorities. Read Mr. A. G. Mohaupt's offer to train you per- And that was our secret. sonally in everything about Radio. By enrolling HANDBOOK So the interviewers, in despair, left us and with us now, you get the benefit of the direct jja 330 PACES hied themselves to Professor Archimedes personal guidance of this well-known expert "I pledge my personal atten- "al i Bukink-who, it probably will be remem- o,"-a -- " bered, was the man tion to every member enrolling _ that had really set this in our Association at this time. whole thing going. Your individual problems and questions will be answered by ' The professor was wholly in the dark. He I-C.S: me. and I will work with you at did not despair, however, but brought reason every stage of the course, guid- MECHANICS' ' Í to bear upon the matter ; in other words, he ing you till fully trained, includ- proceeded "with ing Government examinations HANDBOOK the greatest diffidence, in for Operator's license." = view of the great paucity of data," to pro- A. G. MOHAUPT pound an hypothesis. This celebrated hypo- Mr. HANDIEST book of its kind ever thesis Mohanpt. head of Radio Association of wr'tten. Prepared by experts under of Archimedes Bukink was, 'tis true, America, is a Graduate Electrical Engineer. Uni- the direction of the International Corre. Only rather vague, but, like quite a few things versity of Wisconsin; former Radio Instructor for the U. S. Government; spondence Schools. Note this partial list that are vague, it had not a little in author of "Practice and of subjects: truth it. Theory of Modern Radio." Hydro -mechanics; Strength of Materials; It was something like this : Boller Design; Care and Inspection of Boil- Imprimis, the professor wished it Free 1000 -Mile ers; Horsepower of Boilers; Chimneys; Ex- clearly Radio Outfit haust Heating; Machine Design; Horsepower é understood that the matter was an utter Mail the coupon now for all the facts and free of Engines; Boilers and Pumps; The Slide mystery to him. In the second information. Let us prove to you that Radio is Valve; Belt Pulleys; Rope Belting; Cylinders place, he easier to learn and offers bigger money than any and Steam Chests; Electricity; Currents; had nothing substantial whatever on which other business or profession you Wiring; Dynamos and Meters; Batteries; that can get into. to bottom a single conjecture. Nevertheless, Don't wait. Act while our FREE Offer of a 1000- Compass Surveying; Curves; Leveling; Etc. miile receiving outfit is still in Just fill out and mall the coupon with a dollar bill, lie did conjecture, though, of course, "with effect and this 330 -page I. C. B. Mechanics' Handbook will the be sent to you by return mail. greatest diffidence." And his conjecture RADIO ASSOCIATION OF AMERICA r - - - - -TEAR OUT HERE -----1 was that It, the great mystery It, was in 4513 Ravenswood Ave., Dept. 62 Chicago INTERNATIONAL CORRESPONDENCE SCHOOLS some way connected, though in what way Please send me details regarding your Expert l Box 6100-D, Scranton, Penns. l he had not Home -Training Plan and offer to I I enclose One Dollar. Please the- slightest conception, with representatives, send me-post-paid I also your offer of a 1000 -mile i -the 330 -page I. C. S. Mechanics' Handbook. It Darwin Frontenac's amazing discoveries in Radio Set FREE. I Is understood that If I am not entirely satisfied I I may return this book within suspended animation. five days and you l Noma.. _ . _ will refund my money. Frontenac, the newspaper lowered in his ...... ,,.,-f....._-. Name hands, looked at me, and there was a faint 1 Address I smile in his eyes, a smile 11 of amusement and Address of anger that smoldered. City. - _ __ J (Continued on page 1057) - State- _ . __. 1056 Science and Invention for February, 1925 r a ...ti t it lt 4t t .,. Professor Reginald 4. Fessendcg Dr. Lee DeForest, Ph. D. Learn From These Great Radio Inventors Study the great Stories of how they developed Step by Step, in their laboratories and at home, their great inventions that are now the very foundations of Radio cia There is only one way in which you can learn how to go about inventing. There is only one path to follow, one method that brings success. The lives of the greatest, most prolific, master inventors are a sure, safe guide to your realization of success in this great field. The lives of Radio's two greatest men, Dr. Lee DeForest and Professor Reginald A. Fessenden, constitute a complete course in practical inventing for anyone. The complete stories of these men now running in RADIO NEWS tells just how they strug- gled, h,'w they worked in developing their great inventions. Dr. Lee DeForest invented the modern vacuum tube, that marvelous instrument that makes powerful radio reception and transmission possible. He is also the inventor of the radio receiving system of regeneration that is used in thousands of radio receiving sets today. Professor Reginald A. Fessenden is that great inventor who developed the modern radio telephone. His early experiments in the sending of the human voice without the aid of wires are an inspiration to every inventor young or old. HERE IS YOUR OPPORTUNITY TO FIND OUT HOW OTHERS HAVE SUC- CEEDED IN THE FIELDS OF INVENTING. THE COMPLETE STORIES OF THESE TWO GREAT INVENTORS ARE NOW RUNNING MONTHLY IN "RADIO NEWS." ÍRADICS N Í ON ALL NEWSSTANDS :: 25c THE COPY 8 Published by The Experimenter Publishing Co., Inc., 53 Park Place, NewYork, N.Y. Vato-Jt- eccti Science and Invention for February, 1925 1057 9,ºmnnonnnammun,,,1,1nnna,,,,m,,,,,,,a ,,,,,,,,,,,,,,,,,,,,,,,,,,,,m,,,,,n,,,m,,,,,,1,,,,m,mmm1 The Living DeD.tlhi (Continued from page 1055) Í ..é "The confounded bag -pipe on two legs!" he exclaimed. "Can you imagine how so shrewd a fellow as Bukink sometimes shows himself to be, can be such a colossal, unmiti- a gated, infernal fool?" I couldn't. "But," I queried, "what does it matter? He can never guess the truth." "I wasn't thinking of that," said Frontenac. Aviation Swiftly the days passed, and nearer and nearer drew the day of sailing. Once we Brings Quick motored up into the mountains to see the dogs. The captain had sent the animals to a high altitude, nearly five thousand feet, to save them as much as possible from the Success summer weather. Up there we met Mr. TO young men of daring no other This Man Louis Louisiana. known as Nunatak-he with field of work offers such a fascina- How the one eye blue and the other eye black. tion, such high pay, nor such oppor- It was about a week before the Multnomah tunities for quick success as the field of sailed that I got (after a manner of speak- Aviation. As yet, aviation is practically ing) the surprise of my life. in its infancy. But now is the time to Won Success "It has been my opinion all along," Dar- get in. win Frontenac told me, "that the expedition As an Electrical Expert ought to have a scientist along-to study Amazing Opportunities things geological and biological." in Airplane Industries Genefal Manager of his company at 29 years of aged "And so," said I, wondering at that pause His own boss-owns his home-married and happy end and a In the automobile industry and in the moving protperouº-that's the remarkable success achieved by \Val - of his, "you have got a biologist picture business hundreds of men got rich by lace H. Rohrscluteldcr, now General Manager, Secretary and geologist?" getting in at the start. They made their success Treasurer of the Hustbford Light, Power and Manufactur- woke up. Today, these lines offer of Wisconsin. "No. I have been more fortunate : I have before others ing Company Hustisford, no greater opportunities than a hundred and one Mr. Rohrschneider got his start toward his quick and got a biologist and geologist." others. BUT AVIATION IS NEW. Get in while brilliant success at School of Engineering of Milwaukee. "Oh! Killing two birds with one stone. the opportunities are big. All over the country There he received the practical, Intensive and apeclatlted gentleman is who?" there will be a clamor for trained men. It will not training that enabled him to make good in a big tray. .1nd the accomplished of getting capable men. "Professor Archimedes Bukink." be a question of pay but Why Don't You Get Into "What?" Become an Aviation Expert "Just so," smiled Frontenac. This Big Pay Field? "But-that is, I thought-great Jupiter $50 to $100 per Week The same kind of training that put Mr. Roiarschuolder Ammon, after all the things you've said, The study of aviation is almost as fascinating Into the ranks of the highly -paid Electrical Specialistº will is full of in- title fascinating field of have called that as the actual work. Every lesson qualify you for brilliant success In after all the names you is why it is easy to learn aviation. unlimited opportunities. Come to America's Greatest In a terest. That Learn by actual practice man! You said he was a fool, an ass, do not have to make yourself study-it Is dilution of Electrical Education. You you In our big laboratories with their magnificent equipment. nincompoop, a bonehead, a fuddle -cap--" like reading an interesting book that tells including motors. dynamos, switchboards. Ignition and he was all that and more, things you have always wanted to know. Only lighting systems, etc. Recognized experts give you personal "I did. I said one hour each evening will give you the basic Instruction every step of the way. and I say it again." training in a surprisingly short time. "And yet- One student, S. F. McNaughton, Ch icago, says: Earn Your Way Through said Frontenac, "Archimedes "Your lessons are like a romance, and what "And yet," is more, after one read- This Great College Bukink is anything but a fool when it comes ing, the student gets Tau can earn money to help defray your expense, while to geology and biology." a thorough understand- an Fascinating of you are learning. Our wonderful co-operative plan brings "But the man's utter lack of discretion?" ing. One never tires Electrical Career within the reach of every ambitious men. reading them." James Our Free Employment Department secure, positions for those "I haven't forgotten that, Bond. We must -Daring- Powers, Pa., another of their expenses. In addi- students who wish to earn part " I am in- a good In guard against it, that is all. We mustn't Big Paying student, says, tion, the Department will help you get position deed surprised that the Electrical Industry when your training is completed. let the old calliope know things-things, that Prepare Now for One of These Positions such a valuable course BOOT( FREE-.Malt the coupon today for our big is. we don't want advertised from the be had from such BIG you that can new illustrated catalog. Check the course that Interests Aeronautical instructor practical men for so most and see will send you special information. Read about house-tops." $50 to $150 per week success. little cost." the School that trains men for practical and quick "Well, what on earth will it be next? Aeronautical Engineer !lee hon. easy It Is for you to get the training that will week and a handsome But isn't Bukink getting up in years?" $130 to $300 per enable you to Stop to a splendid position Contractor income. Mall the coupon right NOW. No cost or obligation. No, his years Aeronautical Personal "He's far from senile yet. Enormous profits matter. He'll encounter no hardship, Aeroplane Repairman Instruction won't Men ENGINEERING anyway; his habitat will be Summer Haven. $60 to $75 per week by Experienced SeHalLof a man Aeroplane Mechanician Men who have had ac- of Mllwaukea And, besides (though, of course, i40 to $60 per week tual experience give Dent. S.&I.-225A. 415 Marshall St.. Milwaukee. WIs. doesn't want cripples along in an enterprise Aeroplane Inspector you personal attention. $50 to $75 per week They select the lessons NOW like this) I incline to the captain's belief MAIL COUPON won- Aeroplane Salesmao lectures, blueprints and that, when it comes to these"things, the $5000 per year and on bulletins. They tell you MILWAUKEE ders of youth have been not a little exag- Acre:plane Assembler things that are essen- SCHOOL OF ENGINEERING OF $40 to $65 per week prac- 415 Marshall St., Milwaukee. Wis. tial in everyday Dept S.8.I.-225A, gerated." Aeroplane Builder lesson is or obligation, full particu- tice. Each Please send me without any cost "It may be so. I hope your choice will $75 to $200 per week easy to read and un- lars of the electric,! course I have checked and your big about your institution and how it will fit out a bad one." derstand, Free Book telling me not turn me for a big position in the electrical field. Also tell about your Earn -While -You -Learn plan. "Furthermore, Bond, I am really greatly and Book-Now (Cheek courses interested In, indebted to Granny Bukink-though I would Get Big FREE be sure to glee your education.) coupon below for New Book, just out, "Op- -School of Practical Electricity-6 months or 1 year course. never, never tell him so." Send field. portunities in the Airplane Industry." It is in- Complete general course, revering entire electrical you -Institute of Electrotechnics-12 to 30 months' course. "Indebted ?" teresting and instructive. It will show many Practical electrical training combined eith thorough Acad- "Just so. For look you! Had it not been things you never knew before about aviation. emic education. a limited supply of these books- course. Reg- in all likelihood, We have but -College of Electrical Engineering-3 years' for Archimedes. I should, send the coupon before they are all gone. ular collegiate stork granting B. S. Degree. 14 High School heard the captain's story!" units or diploma from our Institute of Elertroteehnics re- never have entrance. could not help of Aviation quired far Thou- "And, in all probability." I American School -Commercial Electrical Engineering-1 year course. of Michigan Ave., Dept. 14-22 Chicago, Ill sands of Trained Men wanted In this new profession. 14 saying to myself, "we'll wish, every one 3601 11Igh School unite or diploma from our Institute of Electro- us, before this wild business is ended, that wawa teehnlrs required for em range. -School of Automotive Ele-trielty you never had!" course. American School of Aviation -Auto Electrical Service Engineering -1 year 14-22 Chicago, Ill. -Automotive Ele-.tricitz-3 to 6 months. On the fourteenth day of the month (Sep- 3601 Michigan Ave., Dept. -Radio Sales and Service. tember) Nunatak arrived with the clogs. The Without any obligation, send me your tree Book, A.C, and D C. Armature Winding and Motor Generator Opportunities in the Airplane Industry". also infor- Course-3 to d months' course. Brief. but Intensely prac- next day the animals-splendid creatures, mation about your course in Practical Aeronautics. tical, leading to well-paylne positions. -Electrical Home -Service Training with laboratory facul- every one of them-were killed and piled up Milwaukee. ties. for those who cannot time to in the freezer, to he thawed out and resus- Name citated on our arrival at Summer Haven. Name There were one hundred dogs-one hun- St, eet. Street dred and two, to be precise-but the killing was not a long affair. Frontenac stood at State State City City the entrance to the freezing -room and, as a li on page 1059) Age Education (Continued 1058 Science and Invention for February, 1925 nion The Radio Purchaser and :Radio Dealer in an Association for Mutual Benefit Under the auspices of "Radio News," the World's Leading Radio Magazine, an association has been formed, having for íts object, the bringing together of consumer and merchant, in a way that will per- mit every radio owner to save money on his pur- chases. The Radio Union is a mutual benefit association of radio stores and radio enthusiasts. Every member store agrees to give a discount on every sale made to individual members. The member stores will bene- fit because our members will patronize those stores at which they obtain a discount on their purchases- the individual members benefit because they will save money on every radio purchase, and eventually on purchases made for all other necessities, such as groceries, clothing, jewelry, automobile supplies, Officers and Directors drugs, furniture, etc., etc. Every live radio dealer has been invited to join The Radio Union, and contracts stipulating the dis- The personnel of the Officers counts that will be allowed on member's purchases and The are pouring in from every city in this country. Directors of Radio Eventually invitations will be sent to stores selling Union is quite sufficient to all classes of merchandise, in your town, so that very shortly you can make large savings, not only on guarantee the success of the your radio purchases, but on everything else you or new association. The Officers your family buy. The list of membership stores will be sent to every enrolled member. a n d Directors a r e Messrs. The dues for membership will be $5.00, entitling you to life membership, guaranteeing you against any further dues or Hugo and Sidney Gernsback assessments, and entitling you to a discount on every purchase you or any of your immediate family make in and Mr. R. W. DeMott, the store. a membership owners of \Ve want 50,000 Charter members. To these first we offer a the Experimenter membership at only $2.00-a saving of $3.00. Remember this is the only cost-there are no dues or assessments that you will Publishing Company, the pub- ever have to pay. All you must do to obtain your discounts from member stores is to send us once a month, or oftener if lishers of Radio News, Science you wish, the bills or sales slips for purchases made from mem- ber stores. These bills will be verified by the stores from which & Invention, The Experimen- the goods were purchased and they will remit the discounts to us. These savings we forward to you after deducting a small ter, and Motor Camper & Tour- charge for our operating expenses and overhead. ist. These great magazines, You have everything to gain by becoming a member in this Radio Union and can save $3.00 by joining now as a charter member. A single purchase will more than make up the small with their tremendous circula- fee of $2.00 which you pay to join the Association. tion, at the disposal of The Radio Union, assures an over- DO IT TODAY Remember the regular Membership fee will be $5.00 whelming success to the new hereafter. organization. Fill out the application blank, and mail it today with your remittance. 1 ,r7 APPLICATION FOR MEMBERSHIP e THE RADIO UNION, INC., 53 Park Place, New York City, N. Y. 1 Gentlemen-Enclosed you will find Two Dollars ($2.00) for charter Membership fee in The 1 I understand this payment entitles me to a Life Radio Union, Inc. you will Membership and to a discount on every purchase I make in s forward. a membership store, list of which 1 1 NAME STREET 1 TOWN STATE L_ OM MM. S Iffie S~110 S. SI St S1 me _- - S S S S r S ti 4 Science and Invention for February, 1925 1059 , ,,,,,,,, ,aeel The Llvfi ng De fh 1 (Continued from page 1057) = ,.,,,.1..41a.,aw:111,,,,,,,,.,,,1,,,1,,,,,,,,,,,,,,,,,,,,,,,,,,,1,w,w,1,.,,,,,,, '^ Have You Heard THE RADIO SHACK _ dog was brought forward, he made an in- jection in the animal's neck. On the instant. down it dropped, as though a bullet had gone New Shacton Low Loss crashing into its brain. Without more ado, the animal was lifted' up and taken inside, 3 Circuit Receiver? and another dog was brought forward. And so it went, almost with the regularity of C The clock -work. Dog after dog received his in- ' Supreme Achievement jection-the fluid used was a vivid scarlet- ti y ( a' down he dropped, to all appearances as dead with as a doornail, was piled up in the refriger- ator, and another followed. Send for our Catalog VISIDIALS It was a strange sight-a terrible thing to see. It gave Nunatak quite a turn, espe- ASLIGHT turn of the Visidial, then-music, lectures and entertainment cially when he went into the freezing -room of all sorts from all parts of the country. These long, cold winter eve- after the killing was over and saw the frozen nings hold many a surprise for the owners of the new "SHACTON." bodies piled up one on top of another, the For design, construction, performance and ease of operation the SHACTON is the The most important feature and eyes fixed in a glassy, horrible stare. most remarkable achievement in present day radio. without a doubt the cause of SHACTON'S success lies in the fact "The poor brutes !" said Nunatak, unable that Low Loss instruments of the highest grade are used through- PRICE to keep the tears from those strange eyes of out the entire circuit. Equipped with VISIDIALS-dials behind the panel, enabling fine, sharp tuning without vernier. The Visidial his. "You've fixed them now!" adds to the appearance and improves the performance to a surpris- 7 "They're all right," Frontenac assured ing extent. Something new, something better. him. "They are only sleeping, so to speak. STANDARD PARTS ACCESSORIES And they'll be fixed so that the pitching of with VISIDIALS Everything needed to operate after build- ing Is listed here the ship, however violent, cannot budge 17x18 Radion Mahoganite Panel, - Drilled 3 Type 201A Tested Tubes .. $10.35 them." Engraved in Gold. 1 60 -Ampere Hour Storage Battery 11.25 "Sleepin' 1" echoed the mustier. "Yes, 1 Brunswick Low Loss 3 -Circuit Tuning 245 -Volt Extra Large Enco B" they're sleepin'-sleepin' the sleep that we'll Coil. Batteries.. 6.50 1 Genuine Brunswick Low Loss Con- I Pr.3000-OhmHeadPhonesandCord 3.75 all find ourselves in some day. Sleepin' I denser. 1 Antenna Equipment . 1.50 Yes, they're sleepin'. They're dead, that's 1 Brunswick Triploid Mounting Socket 1 Phone Plug, Double. X70 what they are, every one of them, dead as and Binding Post Strip. COMPLETE OUTFIT $34.03 so many pickled mackerel, as you'll find 2 Brunswick Cast Foundation Brackets, Parts also sold separately 2 Brunswick Jacks with Gold -Plated when you to wake them tip. I guess I CABINET FREE try Fronts: 1 for phones, 1 for Loud both Speaker. Order Set and Accessory Outfit know a dead dog when I see one! together, and we will send'Fine Mahog- 1 Freshman Mica Grid Condenser. "Lord help us !" he added. "What is this any Finish Cabinet FREE I here old world of ours comin' to, anyway?" 1 Standard Glass -Enclosed Grid Leak. -Ohm Shacton Bakelite Rheostats MAIL COUPON TODAY The next day. at ten minutes to five in 230 with Gold -Plated Indicators. THE RADIO SHACK, Dept. 13-19 the afternoon, the last line was cast off, and 2 Molded Mahogany Dials grained to 65 Vesey St., New York, N. Y. the Multnomah began to back out into the match panel. Plesso send me the "Shacton" outfit I have A 5 Lengths Professional Bus -Bar. marked. When it arrives 1 will pay the post- fairway. great crowd had gathered, and 1 1 Not man the amount. If I am not satisfied will Special Blue Print for this circuit. to my we certainly received a rousing send-off. a pic- return it in 6 days. and you agree refund an ordinary hook-up but clear money instantly. Mark choice in square. Even the face of Captain Livingstone lighted ture form that a child can understand (A) Complete Building Kit...529.39 0 up. This, however, was but for a few mo- and make. 2 Premier Hegehag Transformers. (B) Operating Outfit...... S3 4.05 ments. A black cloud soddenly cast its ALL ASSEMBLED READY TO WIRE shadow across his features. THE RADIO SHACK Name A few moments, and we had cleared the 55 Vesey Street, New York City Address pier and were out in the stream. The engine City State was reversed ; the Multnomah lost sternway, :f 9E stood still for a few seconds, then began to move forward. The ship's head swung away, over until we had the West Point light a point or two on our starboard bow, when the helmsman steadied the wheel and held her there. We were off-off at last on our strange quest! How strange that quest really was, only three men knew-thought they knew. Sunrise found us off the Dungeness light, with all canvas set (save the square f ore - topsails) and the wind on our starboard beam. The motor was still going, however, for the wind was a light one. But, as the day advanced, it increased to a fresh breeze, when the engine was stopped and we went along under canvas alone, the ship slowly Your 311 -^_ rising and falling now to the long swells coming in from the sea. I n tl sóúTrft.f (To be continued) No extra This 13" x 5P charts for MODERN ASTRONOMY Quick Change Gear F1 all etaIp- Astronomy is lderful, ment shown And interesting 2. SOUTH BEND : under The earth 3volves around the sun Lathe Which makes a year 4 you. CUTTI LA THE el - Only $354 The moon is dead and can't re5 Complete By law of Phy6 great, Easy Payments If Desired 7, This unusual offer comes to you from one of America', largest exclusive builders of Screw Cutting Lathes. established It's where the stars above, 18 years. More than 31,000 of our Lathes 8 5 in use. For example, In plants of 2 largest Steel Companies, In larg- Do nightly scintil8. est Auto Factories, In largest Railroad Shops, in world's largest Sewing Machine Factory, in 2 largest Fire Arm] Factories, by largest 011 Company, and by the U. S. Government. etc. Choice iLna Al irLea BLeanthe If watchful Providence be9, of 96 Styles tSo mFeros FSmoary \Vith You got our latest, finest Lathes, embodying 32 major improvements made In the last toso yeses. You Rot our good inl0tions fraught, signed guarantee on every Lathe and 50 -day trial offer right in your own shop. You take no risk. Did not keep its grand design WRITE FOR FREE CATALOG showing pictures of all our Lathes. Compare our prices with what others ask. Note our liberal guarantee and 30 -day trial offer. Send for Free Catalog today. \Ve should come to O. SOUTH BEND LATHE WORKS, 395 East Madison Street, South Bend, Ind., U. S. A. GEO. GRAY. 1060 Science and Invention for February, 1925 Opportunity Ad -lets YOU will find many remarkable opportunities and real bargains in these columns. It will pay you to read and investigate the offerings made every month by reliable firms, dealers and amateurs from all over the Country. No matter what you may be seeking, whether supplies, automobile accessories, the opportunity to make money, or anything else, you will find listed here the best and most attractive month. specials of the Advertisements in this section twelve cents a word for each insertion. Name and address must be included at the above rate. Cash should accompany all classified advertisements unless placed by an accredited advertising agency. No advertisement for less than 10 words accepted. Ten per cent. discount for 6 issues, 20 per cent. discount for 12 issues. Objectionable or misleading advertisements not accepted. Adver- tisements for the April issue must reach us not later than February 10th. The Circulation of Science and Invention is over 150,000 and climbing every month EXPERIMENTER PUBLISHING CO., INC., 53 Park Place, New York City, N. Y. u..14 Advertising Agencies Agents Wanted (Continued) Books (Continued) Inch Display 100 magazines thrice 58. Beck. 5411 5360.00 a month to distribute everyday household neces- Nature's Finer Forces. Marvelous Scientific Disclosures; Alaska. St Louis. sity in rural and small town districts. No money needed. Lights; Colors; Tones; Vibrations; Odic -Auras; Cold -lights; Million dollar firm behind it. Write for particulars and Radio; Inventions; 210 pages, 53.00. Satisfaction Guaran- wunnmmmnansionolomnmsmumaumnne on nn nu mniu.mnammmnatammumuunn state territory desired. B. U. Johnson, 811 W. Lake, teed; Circulars Free. E. J. Stevens, Publisher. 242 Powell, Chicago. San Francisco. Calif. Agents [Vowed $10 daily silvering mirrors. plating and refinishing lamps. Color Science and Rhythms nearly hundred pages. Start- ling $2. . Agents-Best Jean reflectors, autos, beds, chandeliers by new method. Outfits Revelations. Illustrated. Leatherette binding seller; Rubber Repair for tires and 91.50. Stevens, San tubes; supersedes vulcanization at a saving of over 800 per furnished. Write Gunmetal Co.. Ave. D, Decatur. ILL Paper Doctor 242 Powell Street. cent; put It on cold. It vulcanizes itself in two minutes and Francisco, California. Is guaranteed to last lbe life of We tire or tube; sells to Make from $12.00 to $50,00 a day handling quick selling ...... nmun,....m.mmmili mnumnmm,mm.mmmmimmnnmmmmnmmimmnnnmmmnmmnam every auto owner and accessory dealer. For particulars how auto specialty; part or full time; 3410 per cent profit. Every to make big money and tree sample, address Amazon Rubber auto owner buys on sight Users say doubles mileage on Co.. Dept. 601. Philadelphia. Pa. gas, banishes carbon. increases power on hills. Attached or Business Opportunities detached by anyone to any mate car Its Ore minutes. Ex- Agents-Write for Free Samples. Madison clusive protected territory. quick. Western Specialty Dollars yearly in your baekyard. No mushroom dope. Sell "Better - Write York. Made" Shirts for large Manufacturer direct to wearer. No Co., 2024 Lacolah Bldg., Sioux Falls. S. Dak. Particulars free. Metz. 313 East 89th, Ness capital or experience required. Many earn $100 weekly and bonus. Madison Mills. 564 Broadway. New York. Earn money at home. Addressing, mailing circulars. You can have a business -profession of your own and earn Experience unnecessary. No selling. We pay weekly. York big Income In service fees. A new system of foot correction; Big money and fast sales. Every owner buys gold ini- Supply Co.. Dept. 120, 309 Fifth Ave New York. readily learned by anyone at home In a few weeks. Easy tials for his auto. You charge terms for training, openings everywhere with all the trado $1.50; maid) $1.35. Ten you can attend or goods to buy, orders dally easy. Write for particulars and free samples. Start Mail Order Business. Watch Yourself Grow. Cost tn. No capital required no American Monogram Co. Dept. 71, East N. Sc. agency or soliciting. Address Stephenson Laboratory, 18 Orange, J. Sell by Mall for $1. Particulars free. Tick, 3338 Back Slay, Roston, MLss, Arkansas St., Oakland. Calif. Make $25 to 550 week representing Closes' Famous Phila- Stop Plodding! Be a delphia Hosiery, direct from mill-for men, women, children. Succeed with your awn products-Formulas. Processes. Successful. Operate Tire Repair Every Shop. Make big profits In any locality. We teach you and pair guaranteed. Prices that win. Free book "How Trade -Secrets. Modern master methods. Catalog Free. complete to Start" tells the story. George Closes Company. Desk 27. D. Thaxly Co.. Washington, D. C. furnish equipments $100 tin. Book of Opportunity Philadelphia, Pa. free. Haywood's, 1312 South Oakley Avenue, Chicago. Agents -200 per cent Profit, Wonderful Little Article. Money one sale a day means month.- Get in your mail. "Lambert's Mall Order Se- Only $200 per Five sales, Something new; sells like wildfire. Carry in pocket Write crets" contains methods never before $1,000 per month. Marvelous new adding machine. Re- at once for free sample. Albert Mills, Manager, 2360 successful published. tails $15. Work equals 8.150 machine. Adds, subtracts, American Building. Cincinnati. Ohio. Particulars free. Leon Lambert, 670-D Kaufman Bldg.. multiplies, divides automatically. Speedy, accurate, dur- Wichita, Kansas. able. handsome. Five-year guarantee. Offices, stores, fac- $100 Weekly-Pleasant stork; appointing local agents to tories, garages buy one to dozen. A fortune for live agents. Money making books. formulas, plans, etc. Write for etr- introduce Mother Hubbard Fonds; no canvassing; no deliver- colors. Morris Ave., St. Louis, Write quiets for protected territory and free trial offer. ing; no money invested. Adam Inthout, 556 Congress, Specialty Co., 2007 Park Lightning Calculator Co.. Dept. W., Grand Rapids, Mich. Chicago. Mo. Earn big money fast applying gold initials to autos. Formulas. Nose, Different. Make your own extracts. Live wire salesmen to join our prosperous sales force. flavors, syrups, valu- Every owner buys -51.35 profit on $1.50 sale-particulars Earn $75 to $12.5 weekly from the start --selling the biggest beverages, etc. Name -address brings and samples free. Write quick. Litinogram Co.. Dept. 19, able information free. Meriden Co.. 3322 ML White Bldg.. and fastest selling tailoring line. Set your own profit on Seattle, Wash. East Orange, N. J. earls sale, 300 all -wool fabrics retailing from $22.50 to 545.00. Satisfaction guaranteed. Experience helpful but Earn $25 weekly, spare writing far Earn $10 daily silvering mirrors, plating and refinishing not necessary-we teach you. Write for big line today. time, newspapers. Ambitious men ran herome District Managers. Address magazines. Experience unnecessary. Copyright book free. metalware. chandeliers, bedsteads, headlights. Outfits fur- Press Syndicate, 987, St. Louis, Mo. nished. N. Decie Laboratories, 1133 Broadway, New York. Sales Manager. R. A. Hart. Box 483, Chicago. Illinois. You wish a big income? Your fault If make Make Money with your camera. Lancaster -P. Box 436. $60-$200 a week. Genuine Gold Letters for store win- you don't Los Angeles, dows. Easily applied. Free samples. Liberal offer to fortune. Write to Lucky Spencer for information. 4201 California. general agents. Metallic Letter Co.. 441 B., North Clark, South Main St, Los Angeles, Calif. Chicago. Unlimited possibilities, making toys end novelties at New Improved Automatic Ad -Stamper just out Sales- borne or on a large scale. Particulars free. Ness ~chats, men and sideline men be wise and get In line. Automatic Co., 448 E. 79th St, New York. Agents-Make $25.00-$100.00 weekly selling Comet Spray- Ad Stamper, Joplin, 51o. ers and Autowaslsers to farmers and /Subsists. All brass. 50 Successful Mall -order enterprises and 450 practical Throws continuous stream. Established 30 years. Particu- formulas In book form for 50 cents. Pentland -Service Co.. lars free. Resler Co.. Johnstown, Box Agents-Sell taso shirts for price of one. Walton Duplex Ohio. C47. shirts are reversible. Make $15-025 daily. We deliver. Normalk, Conn. collect. Write for "Your Opportunity." Walton -Duplex $25.00 a day easy! Best line of brushes on the market. Co., 129 Brooks Bldg., Chicago. Free Instructive Book. Start little mail order business; 90 varieties, including famous Auto Fountain Washer. Es- home employment evenings. Outfit furnished Pier. 867 retlent territory available. Write Immediately. Philadelphia Cortland Street. N. Y. Brush Co., Dept. 28. Vineland, N. J. Clothing Sensation! New line of men's clothing. Allwnnl suits all at one low price of $23.50. Nothing htcher. We n.. n , inn ...m...... mw i, n mnnnmmmnmmmnnmmmmmmmom®nmmmnmmmn.mao pay biggest commissions cash oath order. supply finest sell- District Managers Wanted-Appoint Local Agents for us ing outfit and give eo-operation. in locality. powerful 3 to 6 orders a Chemistry your No canvassing or delivering. $100.00 day gives you Income of $60.00 to $125.00 a week. Exoerl- weekly easily made. Commissions advanced Bob Russell, ence Isn't necessary. If honest, and willing Z 2307 Archer. Chicago. Ill. you're earnest Learn Chemistry at Home. Dr. T. O'Conor Sloane noted to worth we'll train you. Address Dept. 280, William C. educator and authority, Bartlett. Inc., 850 W. scientific will teach you. Our home Adams St. Chicago. study correspondence course fits you to take a position as chemist See our ad on 971 Issue. Write and learn how to start profitable business without Agents: 500 page of this Chemical capital or experience. Silvering mirrors, refinishing auto per cent Profit, "Happy Herne Maker Shorn - Institute of New York, 68 W. Broadway. New York City. Poo" builds your osvn big business. Martin of Indiana made Arm, mn.mmmmm.mmmmm , n .n ..1,.1 headlights, tableware plating. Outfit furnished. Interna- $75.00 in day. Missouri ...... tional Laboratories, Dept. 25. 309 Fifth Ave.. New York. one man nsatle $750.00 one month. Exclusive territory. Geo. A. Schmidt & Co., 236B West North Ave., Chicago. Correspondence Courses Agents-Be Independent, make big with our profit soap, Manufacture Potato Big Used correspondence courses of all schools sold, rented toilet articles and household necessities. Get free sample Chips. Profits. Start In own and exchanged. List free. (Courses bought.) Leo ease offer. 110 -Ro. Co.. 2719 Dodier St. St Louis, Mo. kitchen. We furnish sacks. Formula, manufacturing In- Mountain, East structions, sales plan. E. Allen, 5945 Chattanooga, Tenn. Chicago Aeo., Chicago. n. r mmnnmmamnmm...ton,..ton..nnunmmmsmm.m.mm.mmnrmmmmmmnmmnmm.mmrm. mmnnanu..m..m...... n...... o...... m,.....u...... n.m...... no...... n..nu..wmauAnurmwu Make $17 Day.-Finest extracts, food products, toilet Electrical preparations, household necessities. Credit; sample case American Made Toys free. Write for amazing offer. Perkins Products, B-30, Hastings. Nebr. Opportunity to Motors $2.98, twentieth horsepower 115 volt alternating, start Manufacturing Metal Toys and Nov- now. Pay elties. No experience necessary. Enormous demand exceeds direct current. Order postman. Perry Trading supply. furnish. Co., Dept. 1, 81$ Lake. Racine, Wis. We at cost, casting forms for production n.....sasa At Last! Diamond Rival Discovered! Amazing blue and buy entire output, also place yearly contract orders. a loaarsownwem.saaaso.m..awwww nnnmmmmmmmmnvmmnnwnnammm white Rajah Gem astounds jewelry world and deceives Casting forms made to order. Catalog, advice and infor- experts! Beautiful Sample Case Free! $100 weekly! mation free. Metal Cast Products Co., 1896 Boston Road, For Advertisers Write Quiets! Rajah Diamond Co., Dept. F45. Salisbury. New York. N. C. 24 words -355 Rural Weeklies $14.20. Ad -Meyer, 4112 SI, Hartford. St Louis, Mo. Battle Photos and War Relics ...... n.m ...... ,.mm,mm,.wmsaDrmrnmmm,.,m.nnn..r Wonderful Invention eliminates needles for phonographs. Preserves records. Abolishes scratching. Day's supply In For Inventors pocket. $20 daily. Sample on approval if requested. For Dens: Relics Collected from Europe's Battlefields. Ecerplay. Desk H2, McClurg Bldg., Chicago. Firearms, medals, helmets. etc. Illustrated catalogue and sample War photocranhs 25e. Lieut. Welsh, 2117 Regent We Develop Your Ideas Into commercial shape for Pre- Place. Brooklyn, N. Y. sentation to purchasers making working models, drawings, Agents-Something New-Wonderful invention. Ford na..m....nm.mnneon n.m...... mmnm.mmninnum.mnmm limnm mmm.mmmu.mmmn experiments or tests. Courtesy, efficiency, secrecy and ample Owners wild over It-Distributors profit 300%-thirty day equipment; 30 years' experience. Dncorron-Rich Engineer- trial offer. Write A. Z. Super. 1304-Fondulae. Milwau- Books ing Co.. 504 Pacific Mutual Bldg., Los Angeles, Cal. kee. hVls. Free-IIpon request will send you my literature illus- Unpatented Ideas Can Be Sold. I tell you haw and help trating the follovine honks. Astrology, Character. Clair- 3 u make the sale. Pece particulars (Copyriehtedl. Write Agents-$15 a day. Easy. Quick gales. Free auto. Big voyanee. Concentration, Healing. Hvnnotism Maeuetism, W. T. Greene, 808 Jenifer Bldg., Washington. D. C. ireekly bonus. $1.50 premium free to every customer. Simply Medlumshlp, Personal Mfaenetlsm, Personality. Physiog- *how our beautiful, 7 -piece, solid aluminum handle cutlery nomy. Salesmanship, Seership, Success, Sex. Will. Yogi Your Chemical problems solved and Dorking process fur- set Appeals Instantly. We deliver and collect. Pay daily. Philosophy, Gazing Crystals, etc. A. W. for Five W. New Era Mtg. Co., Martens. E. E. nished Dollars. Write me. Stedman Rich- 801 Madison St., Dept 88D. Chicago. 6, Burlington. Iowa. ards, Consulting Chemist, Box 2240'S, Boston. Mass. Science and Invention /or February, 1925 1061 For Inventors (Continued) Instruction (Continued) Patent Attorneys (Continued) concern- Sold promptly. Write Correspondence Courses sold complete; one-third u.ud Inventen: Send @ketch or model for free opinion Patents and pending patents. and cost of Book "ftme American Patents Corporation. Barrister Building. Wash- Pricer because slightly used; easy terms; money back ing patentable nature exact patent. to a sent free. Tells what every Inventor ington. D. C. guarantee. All schools and subjects. Write for special Obtain Patent," Free estalog. Courses bought for cosh. Economy Edu- should know. Established twenty-eight years. Highest ref- Chandler* cator Service. 1122202, West 49th St.. New York. erences. Prompt service. Reasonable charges. Market your own Invention. Booklet free. Chartered & Chandlee, 476 Seventh, Washington. D. C. Association of American Inventors, 635 F Street. Wash- ington, D. C. Be a Laboratory Expert. Earn $300 to $500 monthly. Study Microbiology, Sanitation. Day. Evening Classes. Patents. Write for my free Guide Books 'How to Diplomas. Degrees Granted. Free 71 Piece Outfit to Obtain a Patent" and "Invention and Industry" and "Rec- Students. Write for Free Prospectus Today. International ord of Invention" blank before disclosing inventions. Send College of Microbiology, 2124 Lincoln Ave., Chicago. model or sketch of your invention for Instructions. Prompt- Formulas ness assured. No charge for above Information. Clarence evenings. course A. O'Brien, Registered Potent Lawyer, 929 Security Bank Arthol Shorthand learned in four Full Office. Wash- Moneymaking Books. Plans, Formulas. Catalogue Free. seven dollars. Used everywhere. Sent on approval. Par- Building directly across street from Patent Ideal Book Shop, 5501-E, North Robey. Chicago. ticulars, Hollefreund's Institute, Desk X.. Stratford. Gri- ington, D. C. See page 1035. tarte. Canada. what do you want to manufacture? $2 will bring guar- Patents Procured; Trade Marks Registered-A compre- service for the protection and anteed formula far any product. complete instructions. Con- Correspondence Courses-All schools sold complete at hensive. experienced. prompt sulting Chemists Bureau, Box 1709, Boston, Mass. lowest prices. Easy terms, money -back guarantee. Courses development of your ideas. Preliminary advice gladly fur- bought for cash. Catalog Free. Mention Subject Economy nished without charge. Booklet of information and form for disclosing idea free on request. Richard B. Owen. 130 1111111111111111111111111 lllll 1111111111111 Educator Service, 442-H Sansome, San Francisco. oto,:m::mo ,:ll:m1,:,m::::1 mmm11:m neo:::::: Owen Bldg., Washington, D. C., or 2278-T Woolworth For Sale Bldg., Ness York. Inventions for cale Monroe Miller, Ouray Bldg., Washington. D. C. Patent Super Heterodyne. manufactured by Experimenters' Infor- Attorney; Mechanical, Electrical Expert. Free Blue Book mation Company. The Rolls Royce set There is no better Invention for sale. Traffic congestion eliminator. Autos. gives candid advice. set than this on the market Fully assembled and wired Trolleys, 107 Station A, Boston. by the Company in expensive mahogany cabinet. bakelite Inventors-Send for form "Evidence of Conception" to be panel, ready to operate. Due to death of owner. outfit must signed and witnessed. Form, fee schedule. Information free. be sold. ,'et takes 8 tubes. Size of outfit is 40" by 39" Lancaster end Allwlne, Registered Patent Attorneys in by 10". Set originally cost owner 9200. No reasonable Languages United States and Canada, 242 Ouray Bldg., Washington. offer refused. Box No. 200, Science & Invention. D. C. WorldRomle System, Masterkey to All Languages. :o:,ll. ::::,,:: :::::::l::l:,: ::,,,::,:,:,::,:,, ,o,o,,,,,,.,,: Primers, $1.94: Chinese. French. Spanish. Pronunciation - The Putentome. Impartial advice to inventors and Man- Tables, 30e. Dictionaries, $1.98. Languages, 8 West ufacturers. Malted on request Anderson & Son. Patent For the Photographer 40th, Ness York. and Trade Mark Lawyers, Established 1865. 637 F St.. Washington, D. C. ,,:,,11:1:1::1:::::oo::: :::::::::::::::::::::::.o,:,:, 1.1:::::::::::::11::::,,,,:, 11,:::::t :::::,1:::::::1::1:1o::::::: Have you a Carets? Write for free sample of our bur Mlllloas spent annually for Ideas Hundreds now wanted! magazine. showing how to make better pictures and earn Machinery and Tools Patent yours and prott. Write today for free book-tells money. American Photography, 118 Cameo House, Boston. bow to protect yourself, how to invent, ideas wanted, how I7. Mass. Concrete Building Block Machines and klolda. Catalogue we help you sell. etc. American Industries. Inc., 212 free. Concrete Machine Co., 305 South Third St., St. Kresge Bldg., Washington. D. C. mmma11mnmomnommmm, .1uoe,:e. o1 1 tenieoo m:,,: ,,,,,o11.11,:o1::o,1m111e::o Louis, Ato. Lacey Patent -Sense. "The book the inventor beeps." Games and Entertainment Free. See page 1036. Manufacturing Trick., Puzzles. Jokes, Magical Apparatus, Plays. Stage "Inventors' Guide" free en request; gives valuable in- Mind Acts anal Sensation.) Escape'. fermatics: and advice for all who have original Ideas or Supplies. -Reading To order: Metal articles, simple, or complicated mnchtn- lmprnvements. lOe for 160 -page illustrated 1922 profenionai cata- Frank Ledermann, Registered Attorney and Bend ery. Models, tools, patterns. Experimenting. Parma En- Engineer. 15-E Park Row, New York. logue. Oaks Magical Co., Dept. 549, Oshkosh, Wie. gineering Work., Brooklyn Station, Cleveland, Ohio. Herbert Meteor. Patent Attorney and Mechanical Expert. 606 F Street, Washington, D. C. I report if patent ob- Health Miscellaneous tainable and exact cost Send for circular. Magnetism. Patents-Our book '71mv to Obtain as Patent" sent free Free-Stop using tobacco. hve will give free informa- Hindu Psychology. Yogi. Personal The Se- upon request Contains and Rerults cret Sciences, Books and Courses. Large illustrated Pri- full information about Detente. tion how to conquer habit easily permanently. trade -marks and designs. send a AI, Noce. vate with 25e. If you will us sketch of guaranteed. Anti -Tobacco League Box Omoh,. Catalogue, "How Realize Any Desire." your Invention we will promptly search Ataron. 116 South Michigan. Chicago. make of the Patent Office re-ords and advise you as to patentability, our charge e®,nmmenmm,mmnmmmmnm,mmnm: 1m:on:::::,::::,n:n:: 1,: in for the service being $5.00. Prompt, efficient service with Beautiful registered bull puns cheap. Bulldogs, 501 moderate charges. Over twenty years' experience. Runk and Help Wanted Rockwood, Dallas, Texas. commercial references. Talbert & Talbert. Registered Pat- ent Lawyers, 552 McGill Bldg., Washington, D. C. Cigar Smokers! Factory to Smoker System Saves you Detectives Needed Everywhere. Work home or travel. write Wagner. former half; for particulars and special offer. Montrose Stronger patents for less money. Booklet Free. Char- Experience unnecessary. Write, George Cigar Factory, 4004 Montrose Ave.. Chicago, Ill., Dept. B. tered Association Detective, 1968 Broadway, N. Y. of American Inventora, 635 IS Street. Government Washington. D. C. Get Posted-Good pricey paid for butterflies, Insects. learned. 1m - Silvering Mirrors, French plate. Ea.11y See Sinclair display advertisement page 1026. meneo profits. Plans free. Wear Mirror Works, Excelsior Mo. Springs. Combination Ivory opera -glass, microscope, compass and Patents 60c accept minor, postpald. Elanare Sales Co.. 621 S. Warren All men. women, boys. girls. 17 to 65, willing to St., Trenton, N. J. Government positions. $117-1250, traveling or .tationary. M, P. Laughlin, Patents. Engineer -Attorney, 47 West Me.. immediately. 42nd Street, New York. write Mr. Osment 293 SL Louie, Artificial Marble, sanitary flooring instructions. ornamental casting, concrete, plaster, papier-mache. decoration garden Inventions eommerrlollzed. Patented Detectives Earn Big Money. Travel. Excellent annoy- furniture, 15 years instructing and or unpatented. the public, particulars Write Adam Fisher Mfg. Co., 205 tunity. Great demand everywhere. Experience unnecessary. 200 illustrations free. C. Mahler. Huntington, N. Y. Enright, St. Louis. Mo. Particulars free. Write. American Detective System. 1974 ...,.mw,,,..,,,Mmmmmsrmnnnmmnma®ma®®wnm:.o:mmn: Broadway, N. Y. For Lowest prices on model' and machine work. write. Louis Ulster. 543 Napoleon, Detroit, Mich. Earn $1.20 an hour cutting blanks at home: anywhere; Personal spare time. Men only. Send addressed reply envelope. mmm,m nmmnnmm, Goodyear Sr. 147 W. 23d St.. ew York. Motorcycles-Bicycles Exchange interesting letters with friends in Mexico and Central America. Information free. Box 1647, New Orleans, Men to Build Radio Sets In sisare time. I.eon Lambert. La. 670-H Kaufman Bldg., Wichita, Kansas. Don't buy a Bicycle Motor Attachment until you get our catalogue and prices. Shaw Mfg. Co.. Dept. e. Free to hie, or Women-Information a Galesburg, Kansas. of scientific natura Become a Landscape Architect. T:ncrowded profession of that has brought Physical vigor and happiness to thousand@. wonderful opportunity for money -making. Easily mastered No charge; no obligation. Write Fair Sales Co., Dept by mall. Earn while you learn. LVrtte for book. Ameri- 246-I. Colorado Springs, Colo. can Landscape School, 66-E. Newark. New York. Musical Instruments Be a Detective-Exceptional opportunity; earn big money. Violins-Deep. Mellow, Soulful-on easy credit terma. Lonely Hearts-Exchange letters; make Interesting new Travel. Itig researds. Established 1909. Particulars free. High wonderful friends through our romantic club. Write Eva Moore. Bea City. grade, Instruments M my own make. Dorel- Write C. T. Ludwig, 1417B Westover Bldg.. Kansas onment of many years' expertness. Write for book. Guita 908, Jacksonville, Florida. Me. A. Henning, 2424 Gaylord St. Denver. Colo. Earn $25 weekly, spare time, writing for newspapers, r,moon,mmmm,mmm:mnmum,mnmmnmmmmmmnnmmrmmmaemmvmmmntm,mnm:n:. Get acquainted, Slake new friends. Exchange Letters. magazines. Experience unnecessary. Copyright book free. Enclose stamped envelope for plan. The Lilly Club, Station Press Syndicate, 986. St. Louts, Mo. Novelties II, Cleveland. Ohio. :wires paid for butterflies. insects. ponds Get Posted-Good Ma01e cards, books. novelties, tricks. Catalogue our See Sinclair display advertisement Page 1028. tree. Clllrord Fenner, 2401 Jefferson, Louisville Ky. Lonely-Join Club. Make friends everywhere. Par- ticulars tree. Write Mrs. Mathews. Box 26, Oakland. Calif. Money Slivering Mirrors, Autolight. Radiators. table- ware, Methods Free. Write Sprinkle, Plater. 935, Marion. Patent Attorneys Indiana. Phonographic Supplies Patents. Make money at home writing Showcards. We instruct Send for free booklet. Richest reference.. Best results. Promptness assured. Send model or drawing and provide work. }Calk Shawcord, f1 -J Bond. Toronto, Canada. for examination and opinion. Watson E. Coleman, Patent Build Your Phonograph. Spring Stators, Electric Motors, Attorney. 644 G Street, N. W., Washington. D. C. Tonearss, Amplifiers, Accessories. Latest Equipment lse month. Government Railway Postal in Rad(n Mechanism and Cabinets. Catalog mailed far ten $133.00-$192.00 Get awn Patents. blanks, complete Mfg. & Supply Co.. Clerks. Men, 18 up. Steady. Common education sufficient your Application cents. Hoosier Baldwin Block, Indian- Candidates coached Porticnlars free. Write immediately.' instructions $1. Cutting Bros., Campbell. Calif. apolis, Ind. Franklin Institute, Dept íV23, Rochester, N. Y. Inventors writs me about patents. My fee. payable ,n,mm,wn-nn0000n1111au:mnm:!ms:,,00m:mom:amen::m,,:mmm Firemen. Brakemen, Baggagemen, Sleeping car, train monthly. Booklet free. Frank Fuller, Washington, D. C. porters (entered) 9140-00.00. Experience unneccesary. 897 Photo Finishing Banally Bureau, East St. Louis. Ill. Unnatented Idees Con Be Sold. I tell yes, how and help you make the sale Free particular. (Copyrighted 19231. Write W. T. Greene. 809 Jenifer Bldg., Washington, D. C. Trial Otter. Any size Kodak film developed 5c. Prints 3c each. Trial 5r7 enlargement beautifully mounted 25e. insects Wanted Young Photo Service, 404 Bertha St, Albany, N. Y. "Inventor's Advisor," the valuable Patentbouk with 120 Mechanical movements and illustrations. sent free upon :,,:,,n Get Posted-Good prices paid for butterflies. insects. request. M, I. Labincr. Patent Attorney, 1 Put Bow, See Sinclair display advertisement Page 1026. Ness York. Photo plays, Stories, Etc. M. P. Laughlin, Patents. Engineer -Attorney, 47 West 42nd Street. New Yor x. $ $ $ For Ideas. Photoplay Plots Accepted any form; Instruction revised, criticised, copyrighted, marketed. Advice frees Patent.-Write for our Guide Books and "Record of In- Unfvenai Scenario Corporation, 223 Security Bldg., Santa Learn Chemistry at Heme. Dr. T. O'Conor Sloane, vention Blank" before disclosing Inventions. Send model lllonica & Western. Hollywood, California. noted educator and scientific authority, will teach you. Our or sketch of your Invention for Examination and In.ttue- home study correspondence course fits you to take a position tion'. No charge for the above Information. See adver- as chemist. See our ad on page 971 of this Issue. Chemical tisement on Page 1937. Victor J. Evans & Co., 191 Ninth, Photoplay Idea-Original, for sale. Lucent Annals. Institute of New York, 66 W. Broadway, New York Clty. Washington, D. C. P. O. Box 3814, Station D, Philadelphia, Pa. 1062 Science and Invention for February, 1925 Radio Build Your Radio. Complete line of radio equipment. How to Get a Money saving prices. Complete sets or units ready for assembly. Send ten cents for catalog. Hoosier IlLmufac- Here's a taring & Supply Co., 310 Baldwin Block, Indianapolis, Position with the Indiana. Attention! 50 Vacuum Tube Roots -Ups. The greatest PERMANENT collection of Vacuum Tube Circuits ever brought under two U. S. Government covers at such insignificant cost. These diagrams will be found in the great ''Rasco" catalogue which contains raw materials and pans in a greater profusion than any other Broadcast Station Thousands of appoi fitments are catalogue. 15c in stamps or coin will bring the catalogue made yearly. Good salaries-short to you. Itadlo Specialty Company, 100 Park Place, New hours-liberal vacations (as much York City. MAP as 30 days in some branches of Boys, don't overlook this! The "Rasco" Baby Detec- tor. Greatest detector ever brought out with molded bale. the service). Positions open now Fully adjustable. See former advertisements in this pub- and in other cities. lication or our catalogue. Detector with Galena Crystal in Washington complete, 50c; the same Detector with Radtoeite Crystal, and influence unneces- 75c, prepaid. Send for yours today. Radio Specialty Dio BRonDcsr MAP "Pull" Co., 100 Park Place. Ness York City. \ 1. i Common school education a orearais_ -"a sary. -R unm sufficient as groundwork for most Send me Your burned out or broken Power tubes -50 watts pT Q or over. íV111 pay liberally. W. Baker, 36 W. 20th St, positions. The International New York City. Correspondence Schools will pre- Have your broken and burned out power tubes repaired, palazoihrit pare you right at home to pass 50 watts or over. Send them to us for Repair. Charges your Civil Service examination reasonable. Wm. Baker, 36 W. 20th St., New York City. with a high mark. 2650 Miles Distance with one tube. Any Novice under- stands our Simplified instructions. Big Free booklet IL effii, Mail the coupon today for 48 -page tells We story. Vasco Radio Co., Box SC -117. Oakland. Calif. lir I Free Civil Service booklet. a y _ ,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,M1,,,,maa1,,,,,,,,,,,11an,,,,a,amee,1,,,,,,,,,,,lll,,,,,,..,,mm :j 7- `t 1 If I .,- I rINTERNATIONAL COn9ESPONDENCE SCIIOOLs Salesmen Wanted Box 6197-D. Scranton, Penna. send me a copy I Without cost or obligation, please A Salesman wanted in every town or city within 25 miles of your 48 -page CIVIL SERI ICE BOOKLET, of a broadcasting station sell Badlogem, a posi- to the complete Complete Map Mounted on which tells how I can secure good -paying radio receiving set that retails for $2.50. with Radlogem tion with the U. S. Government. there Is nothing else to buy-the outfit includes the Radio - gem receiving apparatus, 1,000 -ohm phone, and aerial out- Heavy Cloth with Special Name fit The cheapest radio outfit on the market-yet sa prac- tical as the most expensive. Big money to the right mess. Send $2.00 for sample outfit. The Badlogem Corry. 66R Distance Finder Attached I Address West Broadway, N. Y. City. Distributors: Wonderful Pricing System for all Stores. The Consrad Radio Map is different from Absolute protection. Immediate sales! Tremendous Earn- all other maps in that it is printed on ings!! Millen 311g. Co., Dept. JF, 100 Boylston, Boston, CLOTH, with proper care will last a life- Mass. time. The Map measures 17x22" and contains a Distributors-Screw-holding Screw Driver. Handiest Tool special distance -computing gauge of our ever invented. Unlimited Market Tremendous demand! own design which enables one to determine Itig repeat earnings! Write Coburn Tool, 738M. Boylston. the dtstatce in miles betscern any broadcast Boston, Mass. - station and his receiving set at a glance. Another special feature of this man is a mironmmmmmmmmmmmm,mm n nmmmemmmnimmnmmmm nninwmm,wmnrmmn om novel Finder device for locating a broadcast Stanips and station in quick time. Coins A complete list of broadcast stations are given on a separate sheet which can he fas- California Gold, quarter glee, 27e; half -dollar size, 53c. tened to the map by ordinary paper fasten- Columbian nickel nod catalogue, 10c. Norman Shultz. Box ers. 'I ti I 'a áí : 146, Colorado Spring, Colo. The map furnished in taco colors with the sheet of broadcast stations, enclosed in a Stamps In0 Ail Different 3 tents. S. I. Quaker Stamp taro -color heavy manila envelope 9'h x 12 otels Start ou With Company, Toledo, O. inches. 158 Genuine Foreign Stamen. Mexico tear Issues. Ven- Salaries up to $3.500 a Year ezuela. Salvador and India Service, Onatemala. China. etc., only 5c. Finest approval sheets 50 to 60%. Acosta PRICE with vow. living; - %Vented. Die 72-p. Lists Free. We buy stomps. Estab- Hotels, restaurants, clubs, apartments, everywhere need lished 20 years. Hussman Stamp Co., Dept. 156. St. trained men and women-salaries to start up to $3.500 a Louis, Mo. year with your living. Over 70,000 high-class positions paying up to 910,000 n year are otsen even' year In the You'll get profit and 'densere collecting old coins. Send hotels of the United States. Today is 10c for genuine old and large coin is 50c this the FIRST IN- coin cateloc. This DUSTRY IN AMERICA with over 6992.391.968 In new Jost a get -acquainted otter. Send today. You'll be de - hotels being built in 1921-exceeding by $200,000,000 the Heisted with It B. Sfax Mehl, Numismatist Dent. N. SOLD BY ALL RADIO next largest Industry. These new hotels, restaurants. etc.. Mehl Building, Fort Worth, 'rezas. Largest Coln Firm will need over 60.000 trained men and women. in U. S. AND NEWS DEALERS You can have one of these high-class big -pay positions. with luxurious meals and apartment and fascinating work. No Danzig Free-Nice Set Dangle Stomps with Biggest Cat- previous experience necessary. The Lewis Schools guarantee alogues Issued, 2c postage. Midland Stamp Co.. Station Published by to give you the valuable knmrledge that It has taken some E12, Toronto, Canada. of the most successful hotel men years to obtain-men who are now malane 55,000 to $50,000 a year. We train you by Stamns Free-Variety svith mail in your spare time at home with Lewis Simplified Packet, Foreign Stamps Cata- The Study the logue -2c pes'age. Gray Stamp Company, Station E.S. Consrad Company Plan, and we put you In touch with big opnortunitles. Toronto. Canada. Our students employed, our methods endorsed by leading 233 Fulton Street, New York, N. Y. hotel men everywhere. Send today for Free Book. "YOUR 1110 OPPORTUNITY." shoving how we can train you for . mmnmmmnmsmnnmmnmmmmxmmmm one of ® these snlendld nn,itines In 20 weeks or less. and expla !nine our Money -Rock Guarantee. LEWIS HOTEL TRAINING SCHOOLS Typewriters Room M-3488 Washington, D. C. Typewriters, all standard makes. 510 up. Fully gssnr- FREE BOOT( COUPON anteed. Free trial. Write for complete illustrated lists. LEWIS TRAINING A PE'' Ft4CT Of7SE HOTEL SCHOOLS. U Northwestern Exchange, 121 N. Francisco Ave., Chicago. shaped at home w'llle you Room M-3488, Washington. D. C. e Jeep. Rapid, painless without Send me obligation the Free Book. "YOUR n nma and safe. The ANITA is BIG OPPORTUNITY." anummmnmm,mmmm, the genuine, unique and Name Wanted most comfortable NOSE Address t ADJUSTER absolutely City State E guaranteed, nighly rec- Detectives Earn Big Money. 5Vnk home or travel. Ex- - ommended by physicians, .... MMMMMMMMMMMMJ perience unnecessary. Write, George Wapner former Govern- Winner Gold Medal Feb. 1923. Write I ment Detective, 1968 Broadway, N. Y. ' for FREE booklet. The ANITA CO. HEW KIND Of BEFORE AFTER,Dept 273 Anita Bids_ Newark. N. J. Nowyou canthrownway forever steel chafing leg 'straps and Young Men-Turn Your other heavy makeshift d e v i ces. For a we! l k no w n American scientist has Spare Time Into Money ! found a new easy way to support rupture assisted Tbetae the overnice of oar men selling' by means of a wonderful little invention weighing leont, dieuact!ve. tailor d less than 1 /25 of an ounce, Not only do you do away tin.. Exclusive pattern. 'BUILT ONHONOR O HONOR THEIR MAKERI" Direct from our " with the obiectional ressure and tight strapping. large, airy mills towwearer. Out of ordinal? aloes. Tre- but you eliminate the 'coming down" of rupture- mendous repeat stnees. We delver for 90o. when Earn big p-offts, prizes and awards selling Not cold In stores. Nat capita or experience required.Write frequently toad9n to `transmistian. So wrest ha. been thee J. W. HEITJAN, Gen. Mgr., CHICAGO SHIRT COMPANY . success of thiewvonderful desire that It In Ming offered to rup- RADIO NEWS. SCIENCE & INVENTION. Chicago Shirt Bldg., Chicago, ill. tured people on en absolute guarantee of eetiafaction or no 119 cost. Drop o postcard er letter requesting fr,e Menthe. to THE EXPERIMENTER, and MOTOR NEW SCIENCE INSTITUTE,450ºClay SL.Stzubenvllle,Ohio CAMPER & TOURIST in your neighbor- hood. We train you as our salesman and pay you liberally for your time. Write at once Straightens Shoulders and we will help you get started. -Increases Pep M. BRIDWELL. THE NATURAL BODY BRACE-Corrects PIMPLES 9 stooping shoulders, straightens the back, given the lungs chance for normal expansion, induces Tour Skin Can Be Quickly Cleared of Pimples, Blackheads. presser breathing. Brings restful relief, comfort, Acne Eruptions on the face or body, Barbers Itch. energy, and pep. For men and women. Eczema, Enlarged Pores and Oily or Shiny Skin. THE EXPERIMENTER PUBLISHING today for my FREE BOOKLET CO. Costsnothing to try it 30 WAritCLEAR-e TONE SEIN,"-telling how 1 53 Park Place New York, N. Y. VIII Write for days free trial offer and free book. FREE cured myoelf after being afflicted 15 yearn. NATURAL BODY BRACE CO. E.S.GIVENS,I68 Chemical Bldg., Kansas Citp.Mo. Howard C. Ra sh5 Pí.286 Rash Bldg., Salina, Kansas Science and Invention for February, 1925 1063 A Chemistry Laboratory for $7.00 Think of it, fellows! Here is a real chemistry outfit with regular chemical apparatus that performs those fascinating, actual chemical experiments. This lnatruction Book CHEMISTRY outfit is not a toy, put up merely to amuse, but a practical laboratory set, with all aro the chemicals, apparata and reagents necessary to perform real work and to teach CHEMICAL the beginner all the secrets of inorganic chemistry. EXPERIMENTER TIaELCo IaspurosTOeTnT DESCRIPTION OF THE OUTFIT m tams The outfit consists of 44 Chemicals and Reagents A good part of the book is devoted to Weights The English all C. P. put up in appropriate wooden boxes, and Measures. The Metric System, m glass bottles, and hermetically closed jars. The System and the U. S. System are fully explained. acids are put up in glass bottles with ground-in glass stoppers, and there is a sufficient quantity of The following tables are furnished: Symbols chemicals supplied (mostly one to two ounces) to and Atomic Weights of the Elements; Measures of make dozens of experiments with each. Weights, Vólume, Capacity and Length; per cent solutions; Conversion of Measure expressed in The apparatus furnished are all of the best parts; poisons and antidotes; and size their technical obtainable make and of standard laboratory common name of chemical substances; formulas d and shape. for cleaning various substances, etc., etc. The Instruction Book is a real Chemistry Course are: for the Beginner. Some of the Contents Among the 100 Experiments arc: Division of Matter: This is a Treatise on Elemen- tary Chemistry and deals with the theory of the How to make chemical tricks; How to make in. Elements, Molecules and Atoms, etc. Chemical visible and magic inks; Ilow to test flour; How to Nomenclature: This explains in simple language test soil; How to make chlorine gas and smoke the derivation of the chemical names of the ele- (German War Gas); How to bleach cloth and ments and their compounds. There is a chapter flowers; How to produce Oxygen and Hydrogen; on Laboratory Operations; Glass IVorking; First How to make chemical colors; How to test Acids Aid; Fire Extinguishers; Experimenters' Aphor- and Alkalies and hundreds of interesting hints isms, etc. and formulas. Complete, $7.00 Sh. Wght., 10 lbs. (Shipped by Express only) (We guarantee shipment within 24 hours after your order is received) $ Every Fellow Wants 700 Instruction hook ~Yu.. the A TREATISE ON ELEMENTARY r1EcrRlcirY 100 FJectriul Experiments robe wo.rn .nn "3ftr Iioq s Elrrtrlr traps"' BOY'S tY'!fr?'oys h ELECTRIC TRO IMPORTING Co. An AR TOLL4 TOYS The Boy's Electric Toys contains: Enough material to make and complete over twenty-five different electrical apparatus without any other tools except a screw- driver furnished with the outfit. Student's chromic plunge battery, compass. galvanometer, solenoid, telephone receiver, electric lamp, etc. Enough various .,n Siam parts, wire, etc., are furnished to make the following apparatus: Electromagnet, electric cannon, magnetic pictures, dancing spiral, electric hammer, galvanometer, voltmeter, hook for telephone receiver, condenser, sensitive microphone, short distance wireless telephone, test storage battery, shocking coil, complete telegraph set, electric riveting machine, electric buzzer, Msslxarfmom dancing fishes, singing telephones, mysterious dancing man, electric jumping Jack, magnetic geometric figures, rheostat, erratic pendulum, electric butterfly, thermo- electric motor, visual telegraph, etc, etc. Vi ith the instruction book we furnish one hundred experiments that can be made with this outfit, nearly all of these being illustrated with superb illustra- tions. No other materials, goods or supplies are necessary. The outfit contains 114 separate pieces of material and 24 pieces of finished articles ready to use at once. The size over all of the outfit is 14 x 9 x 2M. Shipping weight 8 pounds. "The Boy's Electric Toys" outfit as described, $7.00. Immediate shipment. SEND NO MONEY We have so much confidence in these sets that we desire to ship either one to you by express C.O.D. with the privilege of inspection. In other words, we ship on approval. It does not cost you one cent to take a good look at whichever outfit you want, and see if it comes up to your expectations. If it does, pay the express man $7.00, plus express charges. II not, you need not accept it, and we will pay the return charges as well. ELECTRO IMPORTING CO,, 233 Fulton St., New York City 1 10 ELECTRO IMPORTING CO., I ELECTRO IMPORTING CO., 233 Fulton St., New York . 233 Fulton St., New York Please send me by express THE Please send me by express THE CHEMICAL LABORATORY. If BOY'S ELECTRIC TOYS. If I I don't like it I need not accept it. don't like it I need not accept it. If I want it I only pay $7.00 phis If I want it I only pay $7.00 plus the few cents express charge. the few cents express charge. Í m iIIIzIGIi .a .r. -----c5 _ S8I-2-::5 S&I-2-25 1064 Science and Invention for February, 1925 °S-oa Here's a New SEPES 09- e Patt ern . 1 P.0 PPo`o' HOW TO MAKE. A o v°- es OSS .. . RECEIVER Price 50c Each i Build Your Own "LOW LOSS" Receiver with this New Pattern Last year everyone was building Power sets, larger and larger ever published. It contains two full size blueprints, size 14 by grew the already complicated receivers. When more volume 19 inches, giving wiring diagram and panel layout and a com- or greater distance was desired more tubes were added. plete 16 page instruction booklet. The entire pattern is enclosed Everyone overlooked that vital factor of high efficiency, namely in a heavy, two color manila folder size 9 by 12 inches. LOW LOSS. It is the high efficiency of the LOW LOSS The of Receiver that gets the distance, produces clarity and insures blueprint the wiring diagram incorporates a unique ample volume. new idea of inestimable value to the user. The wiring of each circuit is printed in a different color, thus: GREEN for the Consrad has just published a New Pattern. A standard, high aerial circuit, YELLOW for the low potential or ground, RED efficiency LOW LOSS receiver that embodies every notable for plate and "B" Battery and WHITE for the grid circuit. modern advance along that line. This new pattern is the most Altogether the user of this pattern has every modern aid that complete, most practical and most easily understood pattern has been designed for the building of sets from blueprints. CONSRAD PATTERNS-HOW TO BUILD Pattern No. I-Short Wave Reoenera- Pattern contains 2 full size blueprints Pattern No. 9 --The S.T.ISO Receiver Pattern No. 12-A Portable Receiver tive Receiver 16" by 22" and a complete illustrated Especially designed, catalogue. This circuit spread like wildfire There are ten thousand Uses for a single circuit abroad. Those in the States good receiver pattern that Incorporates all United portable receiver. Consrad hen Patern No. who have tried have a those refinements that give such 5-A Reflex Receiver it obtained aston- developed Inn. coat highly efficient re- ishing results. The Contains receiver for use. markable results. Pattern contains 2 Hero is a reflex receiver anyone ran pattern general Pattern is of every essential to the complete con- standard size and Is blueprints. size 16" by build, details are reduced a complete in even' 22" and a to mini- struction of the outfit. respect so fire page instruction book. mum. Pattern contains the usual full that the user will have no difficulty In constructing this set. Pattern No. size blueprints and four page instruc- 2-One and Two Stage tion booklet. Pattern No, 10-The Ultradyno Amplifiers Receiver Pattern No. 13-A Harkness Receiver Everyone likes Pattern No. to add some amplifi- 6-A Cockaday Receiver The ultimate In Super -6 tube cir- One of the latest and finest of the cation to his set at same time or other. The four circuit tuner. with the per- cuits. It engages the "Ntodulation Ctnsrad Patterns. The modern. popu- This remarkable pattern gives full de- System." a very valuable tails with blueprints fect regeneration Control on all wave asset to tito lar Harkness. Each pattern contains of circuits. etc. lengths, that gets those consistent re- high -power set. Pattern contains a full size blueprints of wiring diagram, Pattern No. 3-A Radiophone Crystal sults. Pattern Contains 2 full size four page booklet and one extra large panel layout and a special complete Set blueprints and complete booklet of in- blueprint containing wiring diagram, instruction booklet for use. The crystl set complete. With pat- structions. coil windings, panel layout. etc. terns. blueprint. Patton No. 14-The Super -Hetero- Instruction folder con- Pattern No. 7-A Neutrodyne Receiver Pattern No. 11-The Five Tube Cocka- dyne Receiver taining illustrations and full details. day The five tube Neutrodyne--one of The greatest of Radio Patterns giv- Pattern No. 4-A Reinartz Receiver todio s greatest circuits. Thls pattern The modern, successful Cockaday with ing complete blueprints and a beautiful contains a One of Radio's most popular hook- complete diagram of the the push-pull system of amplification. 16 page instruction book on Just ',OW to wiring diagram and, one of the panel Exceptionally fine for long distance re- construct the Super -Hetero- ups. noted for its distance getting ca- layout genuine pacity and simplicity of construction. together with a four page in- ception. Contains the usual large size dyne. sttvctfon booklet, blueprints of wiring, panel layout, etc. PRICE SI.00 All Patterns -50c. 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