sou 



SOUND, velocity of. (Phil Trans. 1823. ; 



The velocity with which vibrations are propagated through the air, is 

 the same that a heavy body would acquire by falling through half the 

 height of the homogeneous atmosphere, or that which the atmosphere 

 would be reduced to, if it were everywhere of the same density, and the 

 same temperature with the air at the surface of the earth. 



The height of this homogeneous atmosphere has been computed at 

 4343 fathoms, when the temperature is that of freezing. If this height f 

 be called H, then r, the velocity of the aerial vibrations, = ^ 2 g H. 

 Hence v 1057, which is too small, see infra. 



The velocity of sound has been variously given by different philoso- 

 phers, as appears from the following Table : 



Feet. 



Newton -- . 963 per second. 



Roberts ~ 1300 



Boyle 1200 



Walker 1338 



Flamstead, Halley, and Derham 1142 



Florentine Academy ~~~ ^^^v^^* 1143 



French Academy ~~~ f ~~, w ~~.~^~ 1172 



More modern determinations. 



Millington -~~ ,~~~ ~^~ 1130 Chili. 



Bengenberg ~~* , 1005 Busseldorf. 



LaCaille , 110G Moutaiartre. 



Lacaille 1130 



Flamstead's and Halley's measure, or 1142, is the one generally as- 

 turned by English writers. 



m 



