THE mounting and grouping of exhibition specimens as practised at our National Museum of Natural History, has developed into a fine art. A particularly striking group of fossil remains of the great ground-sloth has just been completed, and in the current Supplement, No. 1857, Mr. Beasley tells us about these giants of the past, and the good work accomplished in setting up in realistic arrangement these representatives of an age long gone by.amp; mdash; In questions relating to social conditions it is unfortunately veryamp; rdquo; difficult to arrive at thoroughly objective conclusions, independent of subjective bias, and therefore accepted by all who devote serious thought to the subject. An attempt to apply objective methods of scientific experiment to questions of labor and wages is reported on in a very interesting article by D. A. Imbert. amp; mdash; That the timeamp; apos; of day varies from place to place on our globe is a fact known to every schoolboy. But with all the details of the circumstances, which determine the amp; ldquo; true solar dayamp; sol; amp; apos; probably not very many of us are acquainted. An article contrib- Judge the Quality of an Automobile by the Speed Indicator It Carries SINCE we told the public where to look for the outward evidence amp; apos; of inward quality in a car, the Automobile Buying and USing Public has been Looking for the Speed Indicator. Now Note the Resultamp; mdash; They have found (as we said they would) that the car with the Warner on the dash was almost invariably good and reliable. And on the other hand, that the great proportion of the cars they examined which had inferior and unreliable speed indicators on them were acknowledged by those who know camp; laquo; rs, to be inferior and unreliable automobiles. The only excuse a manufacturer of a good car can offer for putting on an inferior and unreliable speed indicator as equipment is price. Buyers reason that if such a manufacturer is willing to save money so glaringly in one place that there is room for reasonable doubt as to the quality of the car in other respects. To get a line on the real quality of an automobile, look for the speed indicator. The Warner Auto-Meter is the highest priced speed indicating instrument made. It is a true instrument in every sense. amp; apos; It is known to be sensitive, accurate and reliable. Hundreds of users have transferred their Warner to the sixth and seventh car. These Warners have indicated a mileage up to 90,000 and 100,000 milesamp; mdash; yet are as reliable as when new. The Warner on the dash indicates the intention of the manufacturer or owner to value quality above price amp; mdash; to give or have the best. Reliable manufacturers are consequently equipping or recommending the Warner Auto-Meter with their cars. Other manufacturers and their agents and dealers are figuring how to give a convincing answer to the buyer who asks this question : "How can any car manufacturer claim that he uses the choicest and best of everything throughout his car when the speed indicatoramp; mdash; the most -looked-at thing on the caramp; mdash; is known to be cheap, unreliable and inferior in every way?" Motorists are becoming more and more persistent in asking this q ues t ion and patiently waiting for an answer. Such have little difficulty in getting with their cars an accurate, reliable and wondrously durable Til 10 Warner can be secured through reputable Automobile dealers II any city or town in the United States. Warner branches are maintained in all the principal cities for the convenience of these dealers and their customers. Inquiry to Beloit or at our branches is invited for Warner literature. Warner Instrument Company Main Offices and Factory 1172 Wheeler Ave., Beloit, Wis. Branch Houses Maintained at Atlanta Pittsburg Boston Cleveland Kansas City Portland, Ore. Buffalo Denver Los Angeles San FranCisco Chicago - Detroit New York Seattle Cincinnati Indianapolis Philadelphia St. Louis Canadian Branch, 559 Yonge Street, Toronto, Ont. (130) Model M2, Price amp; dollar; 125 Other Models from amp; dollar; 50 to amp; dollar; 145 See Catalogue 130 August 5, 1911 A Specialized Product; VELOX The only paper madeamp; apos; with sole reference to the requirements of the average amateur negative. Make the most of your vacation negatives. Print them or have them printed on Velox. The Velox Book, free at your dealers or by mail, tells how to handle Velox and all about the wide variety of surfaces and qualities. NEPERA DIVISION, EASTMAN KODAK CO., Rochester, N. Y. JAGER Marine 4-Cycle Engines Skill lull? designed and well built. Single lever control, combining automatic carburetor with spark advance. Develops wide speed ranl.!e and reliability under moat t rymg conditions Sizes 3 to tiO h. p. Send, for catalog. CHAS. J. JAGER CO. 281 Franklin, cor. Batterymarch St. Boston. Mass. BARKER MOTORS Reliable.-l J4amp; rdquo; lo 10 H. P--Economical Their perfect operation and reliability are due tu common sense mechanical ideas and good construction. While low in price, they are made of best materials with careful attention to details. C.L, Barker. Norwalk, Conn engine rprr CATALOG r l\LL WAYNE ENGINE CATALOGUE FREE MARINE AND FARM ENGINES amp; apos; TrMiE WAYNE, a mechanical wonder, e ntire fcrjgmeof uruquedesign. Onlv about one-liiird the moving puts of other motors. Large hand hole phtes, long bearings and new style timer. Catalogue explains fully- Send lor it to-day. THE WAYNE MOTOR COMPANY 272 Jefferson Ate., Detroit, Mich. ELECTRIC MOTORS SPECIAL MACHINES amp; apos; Dynamos flamp; raquo; d SPECIAL Grinders MACHINES Polishers ROTH ELECTRIC MOTORS amp; apos; 98 Loomis Street, Chicago, Ills. Cheapest Water Supply for Country Homes The Niagara Hydraulic Ram will give you ^ running water in any part of your home or barn without any operating cost whatever. Niagara Hydraulic Ram pumpsby water pressure. Cheaperthan Kasolineengine orwindmill, Write today lor catalog AAand guaranteed estimate NIAGARA HYDRAULIC ENGINE CD. 750 Ihh-tl Building, tamp; apos; hiliulelphia Factory, Chester, Pa. amp; apos; water 30 feet for each foot of fall amp; mdash; notroubleor pumping expense. Satisfaction guaranteed. Booklet, plans, esti mate, FREE. RIFE ENGINE CO., 2533 Trinity Bldg. N.Y. Water in Quantity all over your farmamp; mdash; house. field or barnamp; mdash; pumped without cost or trouble for you by an automatic Rife f Bam., Kaise.s ff || IkX Beachy have confidence in his Curtiss Motor when he flew over Niagara Falls and under the Bridge? Everybody knows he must have had absolute confidence. Are YOU going to have as much confidence in the motor YOU are going to install in YOUR aeroplane iamp; apos; YoLl canamp; apos; t if it isnamp; apos; t a Curtiss. Thereamp; apos; s a reason for It. Acquaintance develops confidence. Why not start rignt? 30 H. P. 4 cvI. Power Plant 40 H, P. 4 cy 1. Power Plant 60 H. P. 8 cyl. Power Plant 75 H. P. 8 cyl. Power Plant One of these you Will eventually buy. Get our proposition now. Prompt deliveries. CURTISS MOTOR COMPANY Ilummondsport, N. Y. uted by Professor F. R. Honey, of Trinity College, elucidates these points.amp; mdash; Lieut.-Col. Hubner writes on amp; ldquo; Combination Projectiles,amp; rdquo; a field in which recent years have brought developments exceeding some of the earlier expectations.amp; mdash; amp; ldquo; There is to-day a growing tendency,amp; rdquo; says Mr. S. S. Hough in his article on amp; ldquo; Photography an Aid to Astronomy,amp; rdquo; amp; ldquo; to replace the human eye at the end of the telescope by the photographi c camera.amp; rdquo; The advantages thus gained, and the historical development of astro-photography are set forth by the author.amp; mdash; A new portable gasoline air-compressor suitable for inflating pneumatic tires is described by Mr. F. C. Perkins.amp; mdash; In an article originally published in the Urn-schau, Professor Zuntz gives an account of a new respiration calorimeter used at the Agricultural School at Berlin for investigations in the physiology of nutrition and animal work.amp; mdash; There is also an article by J. W. T. Duval on a moisture tester for grain and other substances.amp; mdash; The second and concluding instalment of the paper by W. H. Dines on amp; ldquo; Practical Applications of Meteorology to Aeronauticsamp; rdquo; appears in this issue, as does also the second instalment of Donald Murrayamp; apos; s article on amp; ldquo; Printing Telegraphy." The Split-log Drag in Road-making THE public roads bureau of the Department of Agriculture has estimated that there are 2,000,000 miles of earth roads in the United States and has suggested an inexpensive way for their improvement. The split log drag is its solution of the problem, and from time to time the bureau issues bulletins informing the farmer how to make it. The main thing needed is a dry red cedar log, although red elm and walnut are useful for the purpose, while box elder, soft maple, or even willow may be employed. Oak, hickory and ash are not recommended. The log, seven to ten feet long and ten to twelve inches in diameter at the butt, is split as near the center as possible, the larger piece being used as the front lof true drag and sometimes being shod with iron along the lower or cutting e d The two slabs on edge and thirty inches apart are fastened together by stakes in such a way that when the drag is in use on one side of a road, the end of the back slab is about sixteen inches nearer the center of the drive-way than the end of the front slab. This gives what is called the setback. Between the heavy slabs and resting on the connecting stakes is a board on which the driver stands. A team of horses is hitched to this completed drag in suoh a way that the drag unloaded will follow at an angle of about forty-five degrees. The teams should be driven with one horse on either side of the right hand wheel track or rut the full length of the part to be dragged, and made to return in the same manner over the other half of the roadway. Such treatment will move the earth toward the center of the roadway ai.d raise it gradually above the surrounding level. There amp; bull; is recommended the use of the split log drag after heavy rains, when the road should be gone over once each way, but much depends on the quality the soil, some roads requiring frequent treatment. The method is said to be most economical. A Peculiar Well.amp; mdash; The attention of the Geological Survey having some time ago been called to a peculiar well in Ohio, an investigation thereof was made. The well produces both fresh and salt water through two separate pumps. The explanation proved to be quite simple. Two water-bearing beds, confined between layers of limestone, occur at this point, one above the water. The pipe of the freshwater pump taps the upper vein at a depth of sixteen feet. The pipe of the salt-water pump touches the lower vein at a depth of thiiity-five feet; and the brine, being heavier than the fresh water, does not mix with it, but remains at the bottom. Aeronautics The European Circuit Race. amp; mdash; The 1,074-mile Paris-London-Paris Circuit race, which started so disastrously, on June 18th, was finally ended on July 7th. Nine aviators out of the 41 who started succeeded in finishing. The race was won by Lieut. Conneau in his Bleriot monoplane, his time being 58 hours and 38 minutes. His actual flying time was 24 hours, which corresponds to an average speed of nearly 45 miles an hour. Roland Garros was second in his Bleriot monoplane with the time of 62 hours, 17 minutes, 16 2amp; sol; 5 seconds. Vidart, in his Deperdussin monoplane, was third, in 73 hours, 32 minutes, 57 3amp; sol; 5 seconds. Vedrines, in his Morane monoplane, came fourth in 86 hours, 37 minutes, 2 seconds. Gibert, on an R. E. P. monoplane, finished fifth, and Kimmerling, on a Som-mer monoplane, sixth. Their times, respectively, were 89: 42 : 34 3amp; sol; 5 and 93: 10: 24 2amp; sol; 5. Maurice Farman biplanes, driven by Renaux and Barra, were seventh and eighth, respectively, their times being 110: 14: 05 2amp; sol; 5 and 206: 21:58. The former aviator was the only one who finished the entire race carrying a passenger. Tabu-teau, with a Bristol (English) biplane, , was the ninth and last to finish. Valentine, an Englishman, flew his Deperdussin monoplane as far as London, but abandoned the race at that point. This race was the greatest test of end urance that has ever been gi von the modern aeroplane. Flights were made m wind, rain, and fog. The greatest elimination occurred in the first stage, in which 23 machines dropped out. The second, third fourth, and fifth stages saw the dropping out of one, three, two, and two machines, respectively, while ten completed the seventh stage and arrived at London. Some of the stages were flown at a speed of over 60 miles an hour. A Flight Across New York City. amp; mdash; On July 8th, Ladis Lewkowitz, a Russian aviator who had previously made a 6,000-foot altitude flight at Nassau Boulevard Aerodrome with his Bleriot monoplane fitted with a 50-horse-power Anzani motor, ascended at that place and fle w to New York. He came above the East River at the Queensborough Bridge and flew up the River to Harlem at a great height. When crossing over the ci ty at an altitude of betwee n 8,OOO and 9,000 feet, his motor stopped and the aviator was obliged to vol plane. This he did with such good results that he crossed the Hudson River and landed in a marsh back of Leonia, some six miles away from where the motor get ve out. His flight and that of Atwood are the only two flights which have bten made above New York since the Statue of Liberty race last October. A Record American Cross-Country Flight.amp; mdash; -A flight somewhat in line with the great long distance races recently held abroad was made the first part of last month by Harry N. Atwood, the young Boston aviator. After having made numerous cross-country trips in the vicinity of the Hub, Atwood flew with his mechanic from Boston to New London, Conn.amp; mdash; a distance of 110 milesamp; mdash; in 2 hours and 10 minutes on June 30th. The trip was made without a stop and in the afternoon the young aviator took aloft the mayor of New Lond on and flew above the Yale-Harvard Varsity boat race. At 7 oamp; apos; clock the next morning, he started for New York, which city he reached in about 3amp; percnt; hours without a stop en route. After alighting and refilling his fuel tank at Astoria, he flew down the East River and across the sky scraper section of Manhattan Island, finally alighting with precision upon Governoramp; apos; s Island. On July 4th he flew the ] 10 miles to Atlantic City in 5amp; percnt; hours, which included several stops for gasoline. He was buffeted by extremely strong heaJ winds all the way. His machine fell in the sea and was demolished when he and Charles K. Hamilton were making an exhibition flight together at Atlantic City, but he persuaded Hamilton to loan him the latteramp; apos; s Burgess-Wright biplane for the balance of the flight. Hamilton had his aeroplane towed over the road from Waterbury, Conn., to Atlantic City, which was accomplished in about a day, and the next morning he and Atwood resumed their "CTamp; ast; Damp; rdquo; Large Line of S lamp; sol; lIV Attachments For Foot I ATIIFC or Power LAHlES Suitable for fine iiccnrale work in the repair shop, garage, tool room and machine shop. Send far Catalogue H SENECA FALLS MFG. CO. 695 Water Street SenecaFalls, N. Y., U.S.A THE SEBASTIAN 15-INCH ENGINE LATHE HIGH GRADE LOW PRICE Automobile Builders, Garages, Repair and Genera 1 Jobbing Shops find this the ideal lathe for their work. Catalog free. The Sebastian Lathe Co. 120 Culvert Stamp; rdquo; Cincinnati, Ohio WORK SHOPS of Wood and Metal Workers, without steam power, eqmpped with BARNESamp; apos; Foot Power MACHINERY allow lower bids on jobs and give greater profit on the work. Machines sent on trial if desired. Catalogamp; sol; ree. W. F.amp; amp; JNO. BARNES CO. 1999 Ruby Street Establish.amp; rdquo; 1872. Rockford, Illinois ?8u USE GRINDSTONES P If so we can supply you. AH sizes mounted and unmounted, always kppt in stock. Remember. wp make a specialtyof selecting stones for all special purposes. Send Jor catalogue amp; ldquo; I." The CLEVELAND STONE CO. 6th Floor, Hickox Bldg., Cleveland, O. MECHANICAL ISUPPLIES and MATERIAL, of all kindamp; ast; . EXPERIMENTAL AND LIGHT MACHINE WORlC 132 MILK STREET BOSTQ,fc| THESCHWERDTLE STAMP CO. jSTEEL STAMPS LETTERS amp; amp; : FIGURES. BRIDGEPORT CONN. Experimentalamp; amp; Model Work Circular and Advice Free Wm. Gardamamp; amp; Son, 80-86 Park Place, N. Y. amp; laquo; r^amp; equals; W. A MTPTi To man utacture METAL tSF W ANTED SPECIALTIES, 20 yeats experience inmaking Dies. Tools and Special Machinery. Expert work. Complete equipment. NATIONAL STAMPINGamp; amp; ELECTRIC WORKS 4 1 E So. GlVmton ., Street, - - Chicago. Ill, Modelsamp; amp; Experimental Work E SPECIAL MACHINERY . .. E. V. BAILLARD CO., 24Frankfort St.,N. Y. MnnFI KICHICAGO MQDELWORKS MASONamp; apos; S NEW PAT. WHIP HOIST for Outrieger hoists. Faster than K levators, and hoist direct from teams. Saves bandli ng at less expense Manfd. by VOLNEY W. HASONamp; amp; TO.. Inc. Providence. U. 1.. U. S. A. UL! 599 lAfamp; apos; Tllamp; apos; IIJamp; apos; IrfH Corliss Engines, Brewers amp; ldquo; and Bottlersamp; apos; Machinery Vho VILTER MFG. CO. Clinton Street, Milwaukee, Wis. amp; copy; WITTE ENGINES^ Gas Gasoline-Distillate orsepower at one cent per hour average, saves fuel, repairs and tune. Cheapest of all powers. Ciiiiii-anteeamp; lt; l Five Years Special price to introduce in new localities. Write for catalog stating size wanted. WITTE IRON WORKS CO. Avenue. Kansas City, Missouri Wizard Repeating amp; laquo; ssa LIQUID PISTOL IHII slop tiltamp; ast; most titi.ms dug (or nmii) without permanent injury. Perfectly-safe to carry without danger of leakage, Fires .and recharges by pulling the L1,s from any Liquid. No cartridges required. mvci one loading. All dealers, or by mail, 5Oc. Rubber With Pistol, 55c. Money- order or U. S. stamps, No coins. PARKER, STEARNS CO., 298 Sheffield Avenue, Brooklyn, N. Y. x shots 1 vered Holster, lOe. amp; bull; HOW TO REMEMBER" Sent Free to .Readers of this Publication Jsamp; equals; You are no greater fntamp; laquo; Hectua1lytharo KEY Tij^^^J^^ your memory. Easy, inexpensive. In-amp; apos; SUCUSS^^^ creases income; gives ready memory for faces, names, business details, Itudies, conversation; develops will, public speaking, personality Send today for Free Booklet. Address DICKSON MEMORY SCHOOL, 700 Andltorlnm Bldg., ChleagO Incorporate Your PATENTS and BUSINESS in ARIZONA Laws the most liberal. Expense the least. Hold meetings. transact business anywhere. Blanks. By-Laws and farms for making stock hill-paid for cash. property or services. free. President Stoddard. FORMER SECRETARY OF ARIZONA. resident aj!ent for many thousand companies. Reference: Any bank in Arizona STODDARD INCORPORATING COMPANY, Box8000 PHOENIX. ARIZONA CRUDE amp; sol; ASBESTOS DIRECT FROM MINES R. H. MARTIN, OFFICE. ST.PAUL BUILOING 220 Bamp; apos; way, NewYork. PREPARED ASBESTOS FIBRE for Manufacturers use August 5, 1911 All Garages W. P. Fulleramp; Co. lJamp; gt; fean Francisco, Cah Ajjunta Veeder Counters to register reciprocating movements or revolutions. Cut full .size. Booklet Free. VEEDER MFG. CO. 18 Sargeant St., Hartford, Conn. Cyclometers, Odometers, Tachometer.amp; ast; . Counters and Fine f.amp; apos; ashnys. Represented in Great Britain by AIabhtamp; amp; Co., Limited, Ii City Ko.id, lamp; apos; insbtirj Square, London, E.C; Prance, by Marktamp; Co., Limited, 107 A venue Parmentier, Pans; Geiamp; apos; Many, Austria-ITiiiisrary Ludw. Loewramp; amp; Co., Huttett Sbast would modernize your home at little cost. A hundred other styles to select from, including Table Lamps and Chandeliers. Each Lamp gives 400 candie-powerat one-half cent an hour. American Lighting Systems are guaranteed to pay for themselves within a few months, and to give complete satisfaction. Seventeen years in the business means that we are reliable. Write fornew catalogue, just issuedamp; mdash; itamp; apos; s FREE, wanted. Good territory still open. AMERICAN CAS MACHINE CO., 143 Clark St., Albert Lea, Minn. Fargo, N. D. Binghamton. N. Y. Complete lists of manufacturers in all lines supplied at short notice at moderate rates. Small and specialists compiled to order at various prices. Estimates should be obtained in advance MUNNamp; amp; COMPANY, Incorporated, PUBLISHERS List Department Box 773 New York City Valuable Books The Scientific American Cyclopedia of Formulas Edited by ALBERT A. HOPKINS. Octavo, 1077 pages. 15,000 Receipts. Cloth, amp; dollar; 5.00; half morocco, amp; dollar; 6.50. This valuable work is a careful compilation of about 15,000 selected formulas, covering nearly every branch of the useful arts and i i.dustries. Never before has such a large collection of valuablef ormulas, useful to everyone. been offered to the public. Those engaged in any branch of industry will probably find in this volume much that is of practica I use in their respective callings. Those in search of salable articles which can be manufactured on a small scale, will find hundreds of most excellent suggestions. It should have a place in every laboratory , factory and home. Concrete Pottery and Garden Furniture By RALPH C. DAVISON. 16mo., 196 pages, 140 illustrations. Price, amp; dollar; 1.50. f1f This book describes in detail in a most practical manner the various method.; of casting concrete for ornamental and useful purposes. It tells how to make all kinds of concrete vases, ornamental flower pots, concrete pedestals, concrete benches, concrete fences, etc. Full practical instructions are given for constructing and finishing the different kinds of molds, making the wire forms or frames, selecting and mixing the ingredients, covering the wire frames, modeling the cement mortar into form. and casting and finishing the va rious objects. With the informa-bon given in this book, any handy man or novice can make many useful and ornamental objects in cement for the adornment of the home or garden. The information on color work alone is worth many times the cost of the book. Handy Manamp; apos; s Workshop and Laboratory Compiled and edited by A. RUSSELL BOND. 12mo., 467 pages, 370 illustrations. Price, amp; dollar; 2.00. t] This is a compilation of hundreds of valuable suggestions and ingenious ideas for the mechanic and those mechanically inclined, and tells how all kinds of jobs can be done with home-made tools and appliances. The suggestions are practical, and the solutions to which they refer are of frequent occurrence. It may be regarded as the best collection of ideas of resourceful men published, and appeals to all those who find use for tooamp; apos; s either in the home or workshop. The book is fully illustrated, in many cases with working drawings, which show dearly how the work is done. .; 4ny of these books will be sent, postpaid, on receipt of advertised price MUNNamp; amp; CO., Inc., Ppubamp; sol; rshers 361 Broadway New York City journey toward Washington. On account of the great humidity they found extreme difficulty in rising more than 150 feet and they were finally obliged to alight near Baltimore because of their inability to clear trees and buildings. The following day (July 11th) Atwood and Hamilton covered the 40 miles remaining between Stemmeramp; apos; s Run and College Park in the early morning hours without mishap. Tnree days later he finished his 576-mile trip to Washington and alighted on the lawn of the White House, where he was greeted by President Taft. In all he took two weeks in which to cover the distance, whereas m the recent circuit race in England, twice this distance was covered in but 31amp; percnt; hours elapsed time by Lieut. Conneau in his Bleriot monoplane. Science Cranes and Herons in Surgery.amp; mdash; M any substances have been employed in turn for making sutures in surgery. Such substances must possess peculiar properties, which are not readily found. Of recent years there has been recommended and used a new material of this kind, the tendons of the legs of cranes and herons. The tests show that these tendons are particularly well suited for surgical use. They are said to form excellent ligatures, and are readily absorbed after the wound has healed. The Exploration of Dutch Guiana.amp; mdash; The expedition that set out from Paramaribo in July, 1910, to explore the only part of Dutch Guiana not previously known to the civilized worldamp; mdash; viz., the upper Corentyn and its tributariesamp; mdash; after suffering the loss of its leader, Eilert de Haan, achieved the object of its labors most successfully under Lieut. Kayser. This expedition was the last of a series that have been working for the past 15 years, under the auspices of the Geographical Society of the Netherlands, in making a complete exploration of the colony. Color Photographs of Atmospheric Phenomena. amp; mdash; The improvements and simplifications lately introduced by ilessrs. Lumiere in the process of color photography were the subject of a recent address by M. Leon Gimpel before the Astronomical Society of France. The method of development has been greatly facilitated by the use of a green light, obtained by applying amp; ldquo; Viridaamp; rdquo; paper to the lantern; while magnesium light is used in printing, and an unlimited number of prints may now be easily produced. Instantaneous pictures are readily taken with plates made hypersensitive, according to the method of Simmen and Tho-vert. M. Gimpel has applied these various improved methods with great sue-cess to the photography of meteorological phenomena amp; mdash; thunderstorms, rainbows, fogs, inundations, auroras. sunsets, etc.amp; mdash; and in the course of his lecture he threw on a screen a number of beautiful pictures of this character. Aerological Observations in Java.amp; mdash; Dr. W. van Bemmelen has published in the Meteoro7ogische Zeitschriamp; sol; t a report on the ftaHore-sorede observations made near Batavia during the year 1910. They are the most extensive series of such observations heretofore made with in the tropics, and the results are in satisfactory agreement with those obtained by Berson, in German East Africa, in 1908. The stratosphere was reached several times. at altitudes ranging from 15 to 18 kilometers, and with temperatures ranging from amp; mdash; 67 deg. C. to amp; mdash; 83.5 deg. C., the latter being the lowest temperature recorded, and, with the exception of Ber-sonamp; apos; s reading of amp; mdash; 83.9 deg. C., the lowest ever observed in the atmosphere. Such readings are, however, uncertain to the extent of some degrees at the great altitudes in question. The average thickness of the westerly monsoon wind was found to be 5.5 kilometers. Many difficulties in the technique of the observations were only partially overcome, but there is every reason to hope that the excellent work in aerology now being carried on by the Dutch observers in Java will in a few years fill the serious gap that has heretofore existed in our knowledge of the upper air, due to the neglect of this class of investigations within the tropics. To Motorists who are about to renew their tire equipment There is no reason why you should spend more money for tires than do the thousands of motorists who use UNITED STATES TIRES. You are in a position now to choose tires, not merely buy them. When you purchased your new car, you naturally took the tires that came with the car. But noamp; lt; w you can judge tires for yourself. You know the standard of service tires ought to give and you know whether or not the tires you have been using have sufficient strength to measure up to that standard. Probably the best reason why thousands of motorists are today forsaking other brands and turning to United States Tires Continental G J Hartford Morganamp; amp; Wright is because they are coming to realize that by combining in each brand the strongest points of four famous makes, United States Tires are unquestionably The Strongest Tires in the World and that this extra strength means far more tire mileage with far less tire trouble than they have been accustomed tamp; lt; ) in tire use of other brands. The oft-quoted statements, amp; ldquo; Have al ways used them,amp; rdquo; and amp; ldquo; Were on my car when I bought it,amp; rdquo; are mighty poor reasons (if they are the only reasons) for renewing with any brand of tires. If tire expense means anything to you, disregard all other reasons and demand the tires that are actually giving users of United States Tires the kind of service that e-uery motorist ivants. It is this extra service, amp; equals; ithout extra cost, that has made United States Tires Americaamp; apos; s PREDOMINANT Tires You can buy them anywhereamp; mdash; four-fifths of all the best dealers handle them. Made in every style and size amp; mdash; American and Millimeter. United States Tire Company Broadway at 58th Street NEW YORK Branches, Agencies or Dealers Everywhere Learn Watchmaking We teach it thoroughly in as many months as it form eriy took years. Does away with tedious apprenticeship. Money earned while studying. Positions se-cu red. Easy terms. Send for catalog. ST. LOTJ1S WATCHMAKING SCHOOL,St. Louis, Mo. Typewriter7YPamp; pound; Onlf Tamp; amp; writers and Other Machines Using Steel Type. Makers of Steel Letters, Metal Stamps, Stencils, Etc. NEW YORK STENCIL WORKS, 100 Nassau St., N. Y. nl TDD CD Expert Manufacturers RUDDER Fine Jobbing Work PARKER, STEARNS amp; amp; CO., 288-290 Sheffield Ave., Brooklyn, N. Y. SINO OR JIJBRIC4TISV Anything amp; ast; xsnx -amp; mdash; , 118.134 North Clinton Sfc C.H BES S.YaCQ f^i^UM New York Electrical School Offers a theoretical and practical course in applied electricity without limit as to time. Instruction, individual. day and night school. Equipment complet.eand up-to-date. Students famp; apos; arn by doing, and by practical application are fitted to enter all fields of electrical industry fully qualitied. School open all year. Write for free prospectus. 27 West Seventeenth Street NEW YORK "This is Great," is what youamp; apos; ll say when you learn oy actual use how quickly and easily you can cut through a board with a Simonds Saw (Pronounced Si-mondj) Youamp; apos; ll especially appreciate a Simonds if youamp; apos; ve been using an inferior saw that you had to drive through by main force. Simonds Saws are made from special Simonds Steel, toughened to stand long service and hardened to hold their sharp edges and set against rough usage. Get a No. 4 Simonds from your dealeramp; mdash; the best saw for the home. Write us for amp; ldquo; The Carpenteramp; apos; s Guide Book amp; apos; amp; apos; amp; mdash; FREE. Contains many valuable hints for everybody. SIMONDS MFG. CO., Fitchburg, Mass. Chicago Portland, Ore. San Francisco New Orleans New York Seattle have about the hous SCIENTIFIC AMERICAN August .5, 1 Iamp; apos; ll The reason whyamp; mdash; the Scientific American holds its old readers and is gaining in circulation so rapidly is that it is interesting. We recently asked our subscribers to send us the names of people whom the:y believed the Scientific American would interest and the amp; ldquo; inter-estingnessamp; rdquo; of the magazine is demonstrated by the large number of the names so received which have been added to our regular subscription list. Have you sent us a list ? If not Here is the way: Simply send us the names and addresses of the people whom you think will be interested and we will do the rest. An accurate record of all names received in this manner is kept, and for each new subscription got from any list we extend the subscription of the person who sent us the list for four months. Thus if we receive three new subscriptions from any one list the subscription of the person who sent us the list will be extended for a full year. Of course you may send as many names as you wish, the greater the number of names you send the larger the number of subscriptions we will probably receive and the longer the period for which your own subscription will be renewed. Be careful to write the names and addresses plainly and donamp; apos; t fail to put your own name and the address at which you are receiving the Scientific American on each list you send. Address all lists to the Circulation Department, Scientific American, 361 Broadway, New York. THE SCIENTIFIC AMERICAN Handbook of rip of 1 ravel With Hints for the Ocean Voyage for European Tours and a Practical Guide to London and Paris :By ALBERT A. HOPKINS, editor of Scientific American amp; apos; l{eference :Boole M~[T At last the ideal guide, the result of twenty years of study and travel, is completed. It is endorsed by every steamship and railroad company in Europe. To those who are not planning a trip it is equally informing. Send for illustrated circular containing one hundred questions out of 2,500 this book will answer. It is mailed free and will give some kind of an idea of the contents of this unique book, which should be in the hands of all readers of the Scientific American. It tells you exactly what you wish to know about a trip abroad and the ocean voyage. WHAT THE BOOK CONTAINS 500 Illustrations The Sea and Its Navigation 6 Color Plates Statistical Information 9 Maps in pocket Automobiling in Europe All About Ships 400 Tours, with prices "A Safer Seaamp; rdquo; Practical Guide to London Ocean Records Practical Guide to Paris Names2,000 Hotels, with prices 500 PAGES, 500 ILLUSTRATIONS FLEXIB LE C O VE R, amp; dollar; 2 .0 0 amp; mdash; F U L L LEATHER, amp; dollar; 2.50 POSTPAID MUNNamp; amp; CO., Inc., amp; apos; Publishers, 361 Broadway, New York City AN IDEAL MAGAZINE FOR THE IDEAL HOME American Homes and Gardens gives its readers the experience of experts in solving the most difficult home problems. It is a thoroughly practical magazine, having the word home for its keynote How to :Build the Home Floor plans and details of construction of houses of moderate cost as well as more pretentious mansions are a feature of each issue. How to amp; apos; Decorate the Home The most experienced decorators in the country describe how the best and most artistic results are attained from the point of expenditure and the more important one of satisfaction. How to Pamp; sol; an and Lay Out the Garden The frame of the house-picture is the garden. and success in its treatment means that each tree and shrub is correctly placed as well as properly grown, hence this department will be found most helpful. Outdoor Life and Jlmusements, Articles on House Industries Every phase of country life is authoritatively discussed from month to month in its pages. American Homes and Gardens is conceded to be the handsomest magazine published in America. Its beautiful cover printed in colors changes each month, and is always a work of art. Subscription price, amp; dollar; 3.00 per year. SPECIAL COMBINATION OFFER AMERICAN HOMESamp; amp; GARDENS, SCIENTIFIC AMERICAN . . . one year( one year\ BOTH amp; dollar; 5 .Q 0 MUNNamp; amp; CO., Inc., Publishers, 361 Broadway, New York CONSERVATION The AUGUST Magazine Number of the SCIENTIFIC AMERICAN Issue of AUGUST 12th, 1911 The next magazine number of the Scientific American, August 12th, 191 1, will contain a series of articles by leading authorities, which will deal with this vital subject of the conservation of our natural resources. Ex-Chief Forester the Hon. Gifford Pinchot, whose earnest fight for the preservation of the coal lands of Alaska has led to a favorable decision of the Land Office, which greatly strengthened the cause of conservation, will open the number with an article on the Conservation of our Forests. The Director and Chief Engineer of the Reclamation Service, F. H. Newell, will write a general article on the past work and future plans of the Reclamation Service. The Director of the Bureau of Mines, Dr. Joseph A. Holmes, will show that the waste of our supplies of coal is due not merely to careless and extravagant management in the mining of the coal, but also and very largely to methods in burning the fuel. Dr. David T. Day, of the United States Geological Survey, will prove, in an article on the conservation of oil and gas, that, as with coal, so with oil and gas, it is possible to effect large economies by judicious management in the oil and natural gas fields and by the use of improved appliances in burning these fuels either for light or power purposes. Dr. Hugh M. Smith, Deputy Commissioner of Fisheries, will contribute an article on the Conservation of Fish, Oysters, etc., and Seals. Conservation is a word to which we are liable to give too restricted an application. In addition to the above articles, the August 12th number will contain the usual Editorial, Aviation, and other departments.