364 A, M. Mayer—Researches in Acoustics. 
ct 
eo 
S 
77) 
oan 
7 
° 
4 
=] 
° 
Ss 
+ 
° 
bn) 
ot 
S 
=] 
oD 
3 
coc 
a 
=a 
fa) 
4 
a 
cr 
<4 
9 
o 
fom 
=) 
<a 
my 
g, 
es 
=) 
ae 
wm 
a 
ie 
of the paper produces, by its reflecting power, an alteration in 
intensity or in pitch. Thus, if we vibrate a fork before the 
mouth of a resonator while the nipple of the latter is open, we 
obtain a far inferior reinforcement to what takes place when the 
nipple is closed Now, the nipple ean be partly closed with a 
gas-flame ora sheet of heated air. Thus, alternately closing 
and opening the nipple of an Ut, resonator with the flame of a 
Bunsen burner, gives excellent results.* The reflectin ; power 
octave Ut, to Ut,. Also, if the plug be taken out of the ends 
of closed organ pipes and these pipes be placed horizontally, 
the reflecting effect of the flame is heard when the latter is 
passed forward and backward across the open ends of the pipes, 
ame or sheets of heated gas, or of cold va asi 
eets 0 pors or gases. 
contemplation of these experiments naturally calls up the ques- 
tion, Is the action of the flame due entirely to reflection? may 
it not also absorb part of the sonorous vibrations, as in the 
analogous phenomena of the reflection of light? If the inten- 
, * In all of the experiments described in this taken that no 
heated air or gases entered the resonators, and Gisrdby pot tien oat of tune. 
