276 



Dr, Moll on the 



[Oct. 



V — /^ = / < P • '0466,82 X 0.„J6 {\+t . 0,00375} 

 "" V 1 3" V p-jY 



= 4/1 10466,82 X 0V6 {1 + ^ . 0,00376} | ^4^, 



According to Laplace, this formula must be multiplied by the 

 square root of the ratio between the specific heat of air at a 

 constant volume, and the specific heat of air at a constant pres- 

 sure. Thus the final formula for the velocity of sound, given 

 by theor y, is 



V = ^-[10466,82 X 0",76{ 1 +< . 0,03375}|^'fjp ^ y/f 



Substituting in this formula the quantities stated above, 

 theory gives the velocity of sound for the state of the atmo- 

 sphere on the 27th of June, 1823, when the experiments were 

 made, V = 335,14 metres, or 1099,885 English feet; but the 

 velocity as obtained by experiment was 340,06 = 1116,032 feet. 



Difference between theory and experiment the 27th of June, 

 4,92 metres = 16,147 feet. 



Experiments on the Velocity of Sound on 2Sth of June, 1823, 

 compared with Theory, 



On the 28th of June, 1823, fourteen simultaneous shots were 

 equally seen and heard on both stations ; the following table 

 contains the results. 



