A. M. Mayer—Researches in Acoustics. 87 
other experiments, the membrane was placed over an opeteng 
in the front of the wooden chamber of a Grenié’s free-reed pipe. 
The ends of several fine fibers from a silk-worm’s cocoon were 
brought neatly together and cemented to one and the same 
point of the membrane, while the other ends of these fibers 
were attached to tuning-forks mounted on their resonant boxes, 
as shown in fig 1. In the experiment which I shall now 
describe, eight forks were thus connected with one point of the 
membrane. The fundamental tone of the pipe was Ut,, of 128 
vibrations per second ; and the pipe was brought into accurate 
unison with a fork giving this sound.* The forks connected 
with the membrane were the harmonic series of Ut,, Ut,, Sol,, 
Ut,, Mi,, Sol,, B®-, Ut,. In the first stage of the experiment 
we will suppose that the fibers are but slightly stretched ; then, 
tral segments. On increasing the tension, the amplitudes of 
these single segments gradually diminish and at last dis- 
appear entirely, so far as the unaided eye can discern, and then 
we have reached the conditions required in our experimental 
confirmation. 
eke Since the number of beats per second given by any harmonic (of a pipe out of 
tune with its h ic series of forks) will be as the order of the harmonic, it is 
better to tune a reed to unison with a fork giving one of its er harmonics. 
I generally used the Sol, fork, or the 3d harmonic. 
