. Natural philosophy. including statics, hydrostatics, pneumatics, dynamics, hydrodynamics, the general theory of undulations, the science of sound, the mechanical theory of music, etc. : designed for the use of normal and grammar schools, and the higher classes in common schools . ^^^^ ^ ^^ — ygSQ-i ft, Ans. 51-8EXERCISE. 284. At what height would the mercury stand in the barometer at an eleva-tion of 29-7 miles above the earthssurface ? Ans. 0-0146 inches. Note.—Divide 297 by 27 (See Art. 212), the quotient is 11, then divide 30 inches by2i ^,i. e. 2048, and the result is the answer. 285. At
. Natural philosophy. including statics, hydrostatics, pneumatics, dynamics, hydrodynamics, the general theory of undulations, the science of sound, the mechanical theory of music, etc. : designed for the use of normal and grammar schools, and the higher classes in common schools . ^^^^ ^ ^^ — ygSQ-i ft, Ans. 51-8EXERCISE. 284. At what height would the mercury stand in the barometer at an eleva-tion of 29-7 miles above the earthssurface ? Ans. 0-0146 inches. Note.—Divide 297 by 27 (See Art. 212), the quotient is 11, then divide 30 inches by2i ^,i. e. 2048, and the result is the answer. 285. At what height will the barometer stand in a balloon which is at anelevation of I63- miles? Ans. -46875 inches. 286. *It is observed that while the baro- meter at the base of a mountainstands at a height of 30 inches, atthe top of the mountain it stands ata height of only 18 inches, requiredthe height of the mountain. Ans. 13000 feet. 287. ♦While the mercury at the base of a mountain stands at the heightof 29-5 inches, at the summit ofthe mountain the barometer indi-cates a pressure of only 20-4 inches,what is the height of the moun-tain ? Ans. 9482-9 feet. 288. fWhile in a balloon the barometer indicates a pressure of only 19inches, at the surface of the earth Fig. * Use Leslies rule. t Use Halleys rule with correction for temperature; i. e„ the second ofhe rules given. 108 PNEUMATICS. [ABTS. 236, 238, the pressure is 29*94 inches—taking the mean temperature ofthe two stations as 72-500, what is the elevation of the balloon ? Jlns. 12703 feet. 236. The common pumj) consists of a barrel SB^ a tube AS, which descends into the water reservoir, a piston cd, moving air-tight in the barrel and two valves, v and x, which act in the same manner as in the exhausting syringe of the air pump. Note l.—When the machine begins to act the piston is raised and pro-duces a vacuum below it in the barrel, and the atmospheric pressure onthe water in the reservoir forces it up the t
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectphysics, bookyear1861
