PAPERS PRESENTED AT GENERAL SESSIONS 



29 



Lr and we use as our unit of absorbing power, the ab- 

 sorbing iDower of 1 meter of cushion, setting a equal to 

 the total absorbing power of room and cushions, we may 



write 



1 



— ^ a l/k or 

 t 



at = k, a constant quantity. 



This experiment yielded the important fact that in a 

 given room, the time of reverberation of sound of a given 



.OS 



initial intensity is inversely proportional to the total ab- 

 sorbing power of the room and its contents. Further, it 

 suggested a means by which the absorbing efficiencies of 

 different materials may lie compared quantitatively with 

 that of some standard material. Thus by substituting 

 for the cushions, a knoAvn area of lieayj^ rugs, let us say, 



