If I wasn't an expert ^f^^ ' I am now r "Since I've used Kester Radio Solder, I do a really slick repair job ! " A "half-way" or messy job of solder- ing radio connections is just naturally impossible when Kester is used! Per- fect, professional results are absolutely assured. First because Kester has the plastic rosin flux that keeps out dust and moisture, and aids receptivity . . . second because it's so easy to use. The flux is inside the solder, and all you have to do is apply heat.The set-builders use Kester ... so should you. Buy it from your radio store or from other dealers ... or try it first at our expense. Kester Solder Company, 4201-05 Wrightwood Ave. Chicago, Illinois. Incorporated 1899. FREE SAMPLE/ Write for it NOW KESTER RADIO SOLDER An Unusual Christmas Gift JOHNSON SEA HORSE Detachable Toy Outboard Motor A minialurt r«pro4uclien ol IhD World limoui •utkvirrf •notor. DrnCD by a powcrluJ spring molar ivith a eaiilriil lever, eompltti wilh braelf ell lartnounling.jiitt ti pic- tured. Runs three minutes, 5 " Hiqh. 3" Wide. Weighs 8 auRces.
- 2—
Post Paid BOAT MODEL SPECIALTY CO. Cnmpiftp ratalog nf moil' el makrrit' litala m*tal jit- tinu», troodi-n btockm.ttc ., itrnt FREK on receipt of 5c to rover ttotitage. A Useful Gift For Your Boy! ©SMOOTH -ALL ■I Bench Plsner (live your boy a chance t> put his eparo tim« to uood UKO. Startapr«(-tl- him wilh Park^ Send now lar descriptive cireultr THE PARKS WOOOWORKIMS MACHIIIE CO. ^ Oapl PS 1? i:»2b KnawMon SI. Cincinnati. Ohip 1 M2.00 Turn Your Wood Lathe Into a Metal Lathe! Stldlnsr Tool Rent fnxUntly attAchiMi to any type w<hk1 latlie withtiin.to I'.f in. swinie. Ways are milled andKihl>ed for tsk«-up. 8 in. cro«H or luniriluiUnal fped. R4'mov«bli; nhicld for tuminx larice diametera at oxtrcmo left. Diir- •blir. Accurate. Fi>r home or cominerrlal nhop. Woiiihl. -JO lbs. Only *12. Sent on FREE t-jt- amiriatlun. Write at unce. Be aure t» titate Bwinit. CLAUSING MFG. CO. BIG FORTUNES WON BY TINY INVENTIONS (Continued from page 124) muir made the electrons do their stuff with a minimum of interference from air mole- cules and thereby made the tube more effi- cient as an electrical oscillator. For fix years, the Langmuir patent was the bone of contention in a scries of heated legal fights, and only a few months ago it was invalidated by the Supreme Court. While granting that Langmuir's tiny change had produced a remarkable improvement, the Court found that the idea of a high vacuum was not Langmuir's, but had been conceived by an engineer named Lilienfcld as far back as 1910. OF AhL improvements brought about with- out making any change whatever in the body of an existing mechanism, the most sen- sational doubtless is William Eibel's perfection of the Fourdrinier paper making machine, used mostly for the manufacture of news- print. Here an industry was revolutionized by a change even smaller than the hole in the glass-molding pipe. All Eibcl did was to jack up the Fourdrinier machine twelve inches! This accelerated the down-flow of the fluid pulp to .such an extent that, when the machine was speeded up in proportion, production was increased from twenty to thirty per cent. In other words, iiibel increased the output from 450 feet of paper per minute to 700 feet, and pointed the way by which paper could be turned out at the rate of 1.000 feet per minute. This slight and almost ridiculously simple change saves from $25,000 to ^;35,000 on technical installation, as the same quantity of paper can be made with one-fourth less machinery, and has radically cut the price of paper. Incidentally, it has made Eibel a rich man. Eibel's patent, too, came before the Supreme Court, and, like Lenke's, was upheld by the late Chief Justice Taft. Though the invention was "as .simple as water running down hill," .said Taft, it had greatly improved the art of paper making and, therefore, deserved to be rewarded with a patent. THERE you have the story in a nutshell of how big fortunes have been won by tiny inventions. Most things appear quite easy after they have been explained, and many a man has wondered why he did not think of some apparently simple device or improvement that yielded a fortune to the one who did. AVERAGE MAN WALKS EIGHT MILES A DAY If you walk nearly eight miles a day you are an average .American in your walking habits, a recent survey shows. The amount a person walks, according to the figures obtained varies from six and a half miles daily, for the store manager, to twenty-five and a half for the farmer with his plow. The postman walks about twenty-two miles every day. A woman shopper covers slightly more than eight miles a day, and a typical house- wife in a year walks as far as the distance from coast to coast. NEW CEMENT ON WOOD A NEW stucco cement may be applied directly to wooden sheathing, where it sticks firmly without the aid of wire mesh. It is used to give a new appearance to an old wooden building. Another use is in repairing existing stucco walls. OPENS A NEW WORLD OF FUN AND EDUCATION — marvellous views of tiny, common objects never seen by the naked eyel Head oi a mosquito dt low masnificdtion. Sea Algae as seen at 50 magnifications. Th fairy lace of a bird's wing feather. Amazing miracles of Nature are everywhere — in a drop of stagnant water, a fly's eye, a mosquito's antennae, a feather, a blade of grass, a bit of your own skin. This re- markable microscope provides endless hours of pleasure and learning.. « For Christmas » Give a New Gem Microscope,^18. Made hy Bausch Lomb, sup' pliers of microscopes to col- leges, doclors, scientists, etc. Easy ad justment, removable base, concave mirror for superior lighting. Rustless chromium and black enamel finish. De- pendable scientific instrument, combining features never before offered at this price. In velvet lined case, with mounted obiect and' plain glass slide, $13, at dealers or postpaid. NEW GEM SCIENCE KIT Contains complete equipment and in- Pt rumen ts for mounting specimens, (;!.is3 slides, instruction book — every* thing for you to start and expand a collection. A fascinating collection which grows more valuable. Complete kit. in handsome durable case, including ?iew Gem Microscope. $28.50. Kit with- out microscope, $ 12.00. Money 'back guarantee. If dealer cannot supply you, use coupon. All described in 24-page booklet, "Microscopy." Send for yours. BAUSCH & LOMB OPTICAL CO. 747 St. Paul Street Roeheiter, N. Y. Dept. 2121 Ottumwa. Iowa CDCC rtc INSTRUCTION rKtt ZDC BOOKLET n.AUSCH LOMB, Rochester, N. Y. Enclosed finj S [ 1 New Ccm Microscope [ ] Kit with New Gem [ ] Kit alone [ ] Free 2 4 -Page Booklet Street Citv and State . PSI2 DECEMBER, 1931 ® Thi> Mai oo an advertiMmenl tigninu the appro»l of POPULAR SCtENCE INSTITUTE OF STANDARDS ...Set pase 8 125 Copyrighted material
