W E ha ve p reviously had occa sion to refer to the fact that the United States Post Office is finding it economical to do some of its own printing, instead of giving out the work to contractors, as heretofore. In the current issue of our SUPPLEMENT, Mr. Gunnaway describes the arrangements which have been made for printing money orders on the government's own presses.-In the second instalment of his article on the Great Star Map, Prof. Turner deals with the subject of “Star Counting.” A note on the variation in the Purchasing Power uf1 Gold should prove of general interest.— We like to keep track, not only of progress at home, but also of the course of events abroad. An article on the electrification of suburban lines in the British capital is published with this object in view.-We have seen the automobile invading a great variety of fields of uscfulness. Th, motor car to the rescue is the modern cry when fire threatens property and life, as is illustrated by an article on a new auto-fire-engine.-The article on Practical Aspects of Printing Telegraphy reaches its ·seventh instalment in this issue.-The Mechanical Handling sf l;reight is a most important technical problem, to the solution of which new contributions are added every day. One example of this is shown in an illustrate.d article.-Factory Economy is the guiding principle ever before the eyes of the works superintendent. A description of an immense superheater utilizing waste heat and installed in one of the plants of the United States Steel Corporation is m. te res tI' ng I. thIO S con nee tI' On.-An ar t1' -cle from the pen of the great genius, Prof. WII h e I m 0 stwald , on th e B'IOlogy of th e Savant, br.mg us one of hI.S IU(ld st?dleS In the PSYChology of great pe : sonahty.-The extractIOn of crude cocaine and l:tS refining process is describe.d I n an artI.cle derived from the Engineer. Materials for Paper Money THE materials that go to make up om' paper money are gathered together from all parts of the world. Part of the paper fiber is linen rag from the Orient. The silk comes from China or Italy. The blue ink is made from German or Canadian cobalt. The black ink is made from Niagara Falls acetylene gas smGne, and most of the green ink is green color mixed in white zinc sulphite made in Germany. The red 10101 in the seal is obtained from a pigment imported from Central Amfrica. $500.00 for This Simple Invention Perhaps some reader of the SCIENTIFIC AMERICAN can help us to solve this problem: We control 92% of the oyster beds from which genuine Blue Point oysters come. Because no one has (ver trade-marked oysters, substitution and fraud are easily possible. How can we mark the shells of our Blue Point oysters so that the consumer can be sure that he is getting the genuine and not a substitute ? The marking must be accomplished without hurting the oyster, or detracting from its flavor or attractiveness. It must be of a nature that will show on both upper and lower shells and that will withstand the water incident to handling the oyster. It must be so distinctive that we can prosecute frauds-those who advertise and offer Blue Points without this mark. The whole cost of trade-marking oysters must be less than 25c a barrel-which contains from 800 to 1800 oysters. We have thought of dipping the point of the oyster in blue plaster of Paris, and of sand-blasting two lines across both shells-but we have never worked either of these methods out. To the inventor who devises a method which we can adopt we will pay $500 in gold. To the inventor who furnishes us with an idea, not complete in itself, but which enables us to perfect a method, we will make a suitable reward. You can easily get oyster shells to experiment with. Send your solution to SEALSHIPT OYSTER SYSTEM, 40 Central Street, BOSTON, MASS. DO YOU HAVE KNIVES TO GRIND, SILVER TO POLISH, SHALL TOOLS TO OPERATE. WASHINC MACHJNES OR WRINGERS TO RUN'i LET THE RED DEVIL. M Water Motor Do Your Work Attacbed to any water faucet will deveJop up )3 H. P. according to size of pipe nnl water oressure. Ollly perfe{'t s\:dl nlotar lade. Improved buej,et wheel eOllstl'tlctioll. G ill. OIolul' tor llechallics IlJld 'l'mdesmen. ,'aslliJlg D achilll, X H. P. on 7 itl. pipe, 80 J'os.water pressure; 1 B'l'. on 60 Ihs. ]tesSlre, 2 ill' lip". “"” ' asll wit h onler. N/, 149'-4 ill. JU ntoI' for gnndhlg, polisllillg. fallS, spwillg madJiues ; for Hoctors, Uputi;ts, JlI I lg-gist .s , etc.o, wi th eme ry,L u i i in g w b eel , silver polis h a m i pu ll e y ,$ :. No. 1493-4 i ll . :lli>. tor a n d p u lley D i l l , $2 .50 , ca sh w it h order. Money b a c l. for any r eason. O rder yyour m otor fro m de ale r or f ro m u s. Sem I your w a ter pr es s u re aT ld siz ! o f su p p l y pipe. Ad i v e Ag < n t s w an ted . Cut al og fr e e . DIVINE WATER MOTOR . DEP'T Ii; UTICA, N.V. ICY-HOT f§ To e Bottle That Keeps Hot Liquids H ot 2 4 Ho u rs Col d Liquid ds s C o l d 3 Da y s Y o u can hav e h o t or c o ld drinks w hil e t r a ve ling, fis hin g, hunti ng , motorin g, etc., keep w a rm m ilk f o r b ab y , co ld wate r fo r child orinv a lid at bedsi de w ithout bo ther. Icy-Ho t J a rs one a d two q ua rts-keep stews, vegetables, etc ., hot without tre-desserts or ice cream cold without ice. Many New Exclusive Features Hnts, $!! p; qufrts, $2.50 up. lee them at dealers—look f ame SeeP Hot on bottom-wite for book. ICY-HOT BOTTLE CO. Dept. F. Cincinnati, O. "That certainly's a real saw, is what you'll say when you feel a Simonds Saw (Ponounced Si-mond;) go right through a piece of wood with little effort. A Simonds Saw does not “chew” its way by sheer force of your arm, like a cheap saw. The hard, tough J tooth points stay sha r p because we make Simonds Steel especially for that purpose. You need a saw at home. Why not get one worth while? At your dealer's, Write us for “ The Carpenter's Guide Book"—FREE. Is full of practical hints. SIMONDS MFG. CO. Fitchburg, Mass: Chicago Portland, Ore. San Francisco New Orleans New York Seattle 238 SCIENTIFIC AMERICAN September n, I D11 POWER SERVICE AT SMALLEST COST To make certain of your power buy a dependable, economical, powerful, and thoroughly efficient I He Gasoline Engine. Maximum power with least fueI. Simple, reliable starters, smooth-running, built right, wo r k right. IHC GASOLINE ENGINES -deliver full rating of power. Select one for your needs-you can't go wrong with an I H C. Thousands of users everywhere know I H C Gasoline Engines are the best to buy. M"de in many styles and sizes from 1 to 35 - H. P.-vertical, horizontal, stationary, portable; air or water-cooled; and tractors 12 to 45 - H. P. Write for complete I H C catalogue. Address INTERNATIONAL HARVESTER CO. OF AMERICA 15 Harvester Bldg. (Incorporated) Chicago USA GOES LIKE SIXTY SELLS LIKE SIXTY J SFOR SIXTY GILSON % GASOLENE :NGINE 'or Pumping, Cream parators, Churns, Wash Machines, etc. FKEE TBIAL ______________._______El Ask for catalog-all sizes GILSON MFG. co. s<>8 Pari St. Post Washington, Wis. $60 m Nulite Gasoline Table tamp A he:lutiful 1:t1llp fol' !lOllleS, 10teis, otlkes, stores, bauks, cajes. I'ortable, safe; (all be tUrlJed upside rlowll or rolled (Ill tile noor without danger or affecting'the JigiJt. soo C. P. of s oft, bt"iliinllt light, one.third (e!lt per hour. Also 200 di1el'tut styles of lamps and systeliis. ACENTS - \e want town, county, null tr:lVeling salesmen. Best proposition ever offered. Selli everywilere. Writ! for Special Offer. National Stamping&Electric Works 412 So. Clinton St. CHICACO STUDY LAW High-Grade Instruction by Correspondence Prepares for the bar. Three Courses: College. Post-Graduate and Business Law. Nineteenth year. Classes begm each month. Send fOI catalog eiving rules for admiSSIOn to the bar of the severa I states. Chlcago Correspondence Sehool of'Law ;06 Ueaper_Block, Chicugo Solders and Soldering f If you want a complete text book on Solders and the art of Soldering. giving practical, working recipes and formulr which can be used by metallurgist, the goldsmith. the silversmith. the jeweler. and the metal-worker in general. read the following Scientific Ameriean Supplements: 1112, 1384. 1841, 1610, 1622. 1434, 1533; price 70 cents by mail. C Order from your newsdealer or from MUNN&COMPANY, Inc. Publishers 361 Broadway New York Get into the auto:obile business wthout any invest:ent We wil l enahle you to get into the automo b ile bUSIness. More than .OO different towns need a new garage and automobile repair shop. We secure for y01 an agency that pays you $175.00 for Bach cal' you sell. We slpply ali necessary tools. Under our syster you l earn the entIre business, chaufftur, repair man and mar.ager. Yul beoil the course at home and can finish right in a far tory where ears are built. We furnish you employment tht day .'-ou sign a contract with f ; we wait for part of our pay alit of your profit s . \rite for Plan No. 127 and handsome catalogue telling: about getting started in the aCitomobile business. The Automobile CoUege of Washington, Inc., Washington, D. C. EASY TO BUY ==g ' 0 ;':': Our monthly payment plan makes it easy for anyone to have the best heating system Buy direct and save the dealer's big profits and excessive charges for installation and repairs. Saves one-third the cost. JAHANT Down Draft FURNACE For residences, schools, hotels, churches, etc. Sold Under a Blndina “Guaranty Bend” to give perfect satisfaction after 365 days' use or money refunded, We send complete outfit-furnace. registers, pipes, special blue print plans, full directions and all tools for installing. So easy to install a boy can do it. OUR FREE CATALOG . Explains the patented Down Draft System fully aad tells why it gives more heat and saves half the cost of fuel. Write for it now. TbeJabant Heating Co. lM1I1 St, AKRON, O. J