44 A. M. Mayer on the Experimental Determination 
relationship of species, and may in this case, perhaps, well be 
abandoned. 
RT. V.—On the Experimental Determination of the relative 
Intensities of Sounds; and on the measurement of the powers 2 
various substances to Reflect and to Transmit Sonorous Vibra- 
tions; by ALFRED M. Mayer, Ph.D. 
(Read before the National Academy of Sciences, in Cambridge, Nov. 21, 1872.) 
Waite the problems of the determination of the pitch of 
sounds and the explanation of timbre have received their com- 
pee elucidation at the hands of Mersenne, Young, De la Tour, 
6nig and Helmholtz, the problem of the accurate experimen- 
tal determination of the relative intensities of given sonorous 
vibrations has never been solved. 
The method I here present will, I hope, open the way to the 
complete solution of this difficult and important problem; and 
I trust that the success I have met with will instigate others, 
more learned and patient, to attack with superior acumen & 
subject which must necessarily become of fundamental import- 
ance in the future progress of acoustic research. 
1. The determination of the relative intensities of sounds of the 
same pttch. 
If two sonorous impulses meet in traversing an elastic 
the impulses from the two resonators meet at the confluence of 
the two branches of the forked tube, and connect the branch of 
