(12548) C. A. E. H. says: I have seen it stated that the mouths of some rivers are higher than their sources. I can see that this may be true of rivers such as the Mississippi, which flow toward the equator through a number ot degrees of latitude. If the water is actually farther from the center of the earth at the moutli, will you kindly explain the force or forces acting upon it to raise It'.' A. All rivers which flow south In tile northern hemisphere, or north in the southern hemisphere, are farther from the center of the earth at their mouths than at their sources. The earth's diameter Is 26 miles longer through the equator than it Is from pole to pole. The theory is that the earth was once soft. and in rotation, and bulged at the equator by centrifugal force. The earth has cooled and become solid, but the centrifugal force remains. The yielding water takes the position which the rotation of the earth requires it to take. The very definition ot a level surface Is one which Is parallel to tile surface of still water. The Mississippi River flowing south does not take this position. It is below that position at its mouth. It really flows down to the Gulf of Mexico, although in so doing it goes farther from the earth's center. The name of the force raising it farther from the center of the earth is “Centrifugal Force." (12549) ,A. J.. 1. says: Kindly settle the following argument for Ile: A friend ot mine contends that after water has assumed the solid state as Ice, provided the pressure is constant, its temperature will remain at 30 deg. F. so long as the temperature of the surrounding medium remains below 32 deg. F., and that if the surrounding medium was to go down to 8 deg. F'. , the temperature of the ice would remain constant. 1 contend that the temperature of the ice varies with the temperature of the surrounding medium, as also does its volume. A.- Water, in the solid state. Is no different from any other solid. All solids rise and fall in temperature as the place in which they are Is heated or cooled. Everybody knows that ice cream, which is largely frozen water, is cooled much below the freezing point and packed to make it keep. Ice also expands and contracts by heating and cooling, just as iron or any other solid does. People are misled by the fact that ice cannot be heated much above 32 deg. Fahr. It melts. but so does every other crystalline solid when it is heated to its melting point. All such substances cannot be heated above the melting point any more than ice can. The peculiarity ot ice Is that it mefts at a very low temperature. Most crystals melt at a much higher temperature than does ice. Ice when below 32 deg. becomes dry. It is easy to see the difference between ice in cold air and ice in warm air. The writer has cooled ice to the temperature of liquid air, more than 300 deg. Fahr. below zero. It crumbled into very small pieces .by Its coptraction at that temperature. (12550) A. F. H. asks: Will ' you please explain through Notes ' and Queries, tile following terms as applied to steel rails : Horizontal Inertia. Vertical Inertia, Moment of Inertia, Section Modulus, Radius of Gyration? A. Consult one of the books on mechanics. such as Merrlman's “Mechanics of Materials,” ($5 It ordered from our Book Department), for a full explanation. Briefly, “moment of inertia” is a term signifying the sum of the masses ot the particles of a body,' each multiplied by the square ot its distance from the center of inertia, which may be a point or an axis. In the rail section herewith, the sum of the masses of the particles multiplied by their distances squared, would be the polar moment of inertia. it all the distances ran together at the crossing of the axes; or the moment' of inertia about the horizontal axis, if the distances all ran vertically to the horizontal line AA; or the moment about .the vertical axis, It the distances ran perpendicular to that axis. The section modulus is the moment of inertia divided by the distance of - the most distant particle from the pole or the axis of inertia. Its value, like the values of the moment of inertia, may be found in the pock-etbooks, for all standard rail sections. The radius of gyration is the distance from the pole or the axis (as the case may be) of inertia to .that point at which, if a 11 the mass of the body were concentrated, the moment of inertia would be the same as tor the original shape. To Start in Business or Increase Your Present Business Oxy Acetylene Welding Plant. complete with Oxygen Generator, CompresaedAcetyleneTank, T oich, Interchangeable T i ps, Valv es. Gau gcs, H o s e. etc .. suite ble for Gatages, Re-patr Shops, M a n utactu-rers, etc., tot $250.00. A s p 1 endid chance to start in business tor yourself or to increases out “ garage or repair shop earnings. Phenomenal profits are made m the repairing, by this orocess, of broken parts ot Automobiles, Machinery and on genei a I tepairs. Mention this advertisement and get full particulars horn WalterMacleod&Co.213 E. Pearl St. Cincinnati, 0. ROBERTS AVIATION MOTORS FIFTY FLYING TODAY 4 (Minders o0 M.I'.. (> (Mmdors 76 H.I'. I AT.U.Oi; I''It ICE Tfae Roberts Motor Co. 1465 Columbus Ave. Sandusky. Ohio Chas. F. Willard Aeronautical Engineer AEROPLANES designed and built to order. Aeroplane exhibitions arranged for and given at short notice. My experience as an aeroplane pilot dates back to the first machine sold by Curtiss and purchased by the Aeronautic Society over three years ago. Address me in care 0/ Scientific American, 361 Btoadway, New York. MAKES A PHONOGRAPH SOUND LIFELIKE THE Morse Clanfier is remarkable little device made to tit in tube between reproducer unci horn of phonographs. It renders-the sound loud, clear and, life-like and eliminates that unpleasant metallic effect which is more or less common to all phonographs, regardless of price. Can be attached pAT AppL.D FOK in a minute by anyone and lasts as long as the mach ine. Thoroughly tested and proven successful. Mailed Prepaid upon Receipt of Price,$1.00. GuaranteedAbsolute-ly Satisfactory or Money Refunded. In ordering please state whether for Victor, Victor-Victrola, Edison with rubber or metal connection, Columbia Disc or Columbia Cylinder. Information and circular matter free. MORSE BROTHERS, Manufacturers and Distributers 448 Lumber Exchange, Minneapolis, Minn. AGENTS -$452fi A WEEK ENDETS mtlj in granite ware, hot water bagu, tin, oopper, I I(looking utensil a, eta. Wo heat, solder, cement or rivet. Ad; one oan I usetnem. Fit any etirfaoe. Smooth. Sample box, lOo. Complete box, 9 aastd. sizes, 25o, postpaid. Wonderful opportunity for live agents. Write I Collette Mfg. Co., Bos 192, Amsterdam, N.I j BIG MONEY FOR YOU Selling our metallic letters tor office windows, store fronts, and, glass signs. Any one can put them ou. Nice, pleasant business. Big demand everywhere. W rite today tor free sample and tull particulars. METALLIC SIGN'LE'fTER CO., 488 North Clark Street""ChIcago Learn Watchmaking We reaeu it thoroughly in aa manv months as it rormeny Took years. Does away with tedious apprenticeship. Money earaedwhilestiidyin;. Positions secured. Easy terras. Send for catalog. ST. LOUIS W ATCIIMAKING SCHOOL. St. Louis, Mo. ni tdd cd Expert Manufacturers RUDDLlX Fine Jobbing Work PARKER, STEARNS &: CO., 288-290 Sheffield Ave., Brooklyn, N. Y. lif'wiijm Corliss Engines. Brewers Bottlers' Machinery lih.. VIL TER MFG. CO. Clinton Street, Milwaukee, WlS- AERO BOOKS Send tod ay for our New List ol Books and Drawings . Spon&Chamberlain 123 S.-A. Liberty Street New York CRUDE ASBESTOS DIRECT FROM MI NES R. H. MARTIN, PREPARED ASBESTOS FIBRE lor Manufacturers use OFFICE. Sr.PAUL BUILDIN0 220 B'way, New York. October 14, 1911 SCIENTIFIC AMERICAN 359 Let the Red Devil Water MotorDoYour Work Improved construction, absolutely perfect, runs inl” machine and a hundred other things, Pnwerfor “ borse poweroo J^-inch pipe, 80 pounds pressure; I 6>inch Motor. your washing Bmall tools. ,,______ _ ......_ r_________ horse power on 2-incfipipe, 60 pounds pressure. New net Price, ,5.00 cash WIth order. c No. 1492 4-inch Motors for grind-ingftfo UshinYtand buffing. Runs sewing machines, faus, bottle washers, etc. Price with emery, buffing wheel, silver polish and pulley, $3.00. No. 1493 Motor and pullew only .2.50. U-horse power on 80 pounds pressure. Improved con- ne 3,000 to 5,000 revolutions per minute. Only scien-tiffical] y and mechanically perfect small water motor manufactured. Patenter! construction makes it possi ble. Tremendous. output warrants the price. Money back for any CATALOGUE AND LARGE SHEET FREE WRITE TO-DAY 6-Incb Bucket Wheel DIVINE WATER. MOTOR. COMPANY Dept. 12. Utica. New York, U.S.A. For the name of your local hardware tool dealer, we will send you free booklet on “Theory and Design of Water Motors." _2A«. 4CKLE | A*Jr^*___^ ^Catalogue M Free of Motors. Catalogue B Free of Boats. i§3 ENGINES FROM 2 TO 4-0 H.P. PALMER BROS., IN STOCK Cos Cob, Corfu. The Pump that Costs Nothing to Operate First cost is nothing when compared with the day-after-(iay operating expense of pumping engines. The. first cost is the only cost when you install a Niagara Hydraulic Ram It is auto!ii;iti(.';illy operated by water pressure. Supplies evf-ry part of the farm and home with running wsiter without trouble or expenst Write for catalogue A A and guaranteed estimate NIAGARA HYDRAULIC ENGINE CO. 750 m-ecl Itldg. I'hila. Factory, Chester, Pa. R I FE Rife Rams are the most satisfactory m a Hjl means of supplying water for your ^8*»%Iwl country place. w Raise water ?O feet for eacb footof fall --no trouble or pumping: expense. Satisfaction guaranteed. Booklet. ffRlt plans. estimate. Free. RIFE ENGINE CO. 2533 Trinity Bldg., N. Y. AIR GAS! Latest Invention Standard Vacuum Gas Machine makes ^automatically! Uses97% ordinary air' Cheapest,safest, most hygienic for lighting, hoatinK \ and coofcinsr! All conveniences of city gas' Non-^ poisonous, non-aspbyxiatine, inexplosive and inodorous! Machine always ready! Gas can be made v?Jn5? p^1000 c";ft-! 25 times cheaper than acct nr rit* ™ueiap|rt-han karosone laniDB. electricity or city gas! Saving will pay for the machine in ?h£Ti TA3; Agents wanted everywhere in ^ febt"*^ Machine of 25 ^ Standard-Gillette Light Co.. 10 H Michigan St., Chicago, U. S. A, THE HOLTZER MAGNETO CLOCK will safeguard your factory. by keeping your watchman awake. Makes indelible. indisputable records. Will reduce insurance costs. too. Send for bulletin 15S2. The Holtzer-Cabot Elec. Co. Brookline, Mass. • Chicago, III. ELECTRIC rTORS * ^ Dynamos SPECIAL Grinders MACHINES Polishers ROTH ELECTRIC MOTORS 198 Loomis Street. Chicago, ills. "POROX" Storage Batteries The best for ignition and light. No loss of current. Absolutely reliable. Transparent iars are used for all batteries. 6 volt, 00 ampere hour battery. Price $24.00. Semd for cafaiooue ALBERT MULLER Hoffman Boulevard, Dear Hillside Ave. JAMAICA. N. Y. BRISTOL'S RECORDING INSTRUMENTS For Pressure, Temperature and Electricity The most complete line of Recording Instruments in the world. Write for new 64-page illustrated Bulletin No. 160 which is a condensed general catalogue of Bristol's Instruments. BRISTOL COMPANY, WATERBURY. CONN.
This article was originally published with the title "Notes and Queries"