ON THE PROPAGATION OF SOUND. 377 



be considered as the measure of the strength of sound, must vary as the 

 square of the distance ; so that, at the distance of ten feet from the sounding 

 body, the velocity of the particles of the medium becomes one tenth as 

 great as at the distance of one foot, and their energy, or the strength of the 

 sound, only one hundredth as great. 



V.OL. I, 3 c 



