204 
Proceedings of Royal Society of Edinburgh. 
[sess. 
Hermann experimented with the ordinary phonograph, and ob- 
tained photographs of the movements of the vibrating glass plate. 
His curves are small, not unlike those seen in Koenig’s flame 
pictures, and they do not seem to me to represent so accurately the 
marks on the wax cylinder as those obtained by my apparatus. 
In many cases they have sharp points. This, however, may not 
interfere with analysis. Pipping’s curves were not obtained from 
the phonograph hut from the vibrations of a minute membrane 
made to represent the drum head of the ear. His curves show 
large periodic waves with minute waves on their summits, and they 
suggest that the large waves may be vibrations due to the mem- 
brane itself. Hot having seen the apparatus, and as the observations 
have been made by one well aware of the possibility of this error, 
I do not venture to do more than suggest this difficulty, especially 
as I now show you a series of tracings on a glass plate very similar 
to those in Pipping’s figures. These were obtained by singing a 
vowel into a receiver furnished with a small membrane to which 
a recorder was attached. The glass plate (smoked) moved rapidly 
across in front of the marker. Alongside of these you will see 
curves obtained directly from the recorder attached to the glass 
disk of a phonograph. In the tracings of another experiment, 
you see waves more like those of Hermann. The larger waves 
in the tracing like that of Pipping, are, I believe, clue in my 
experiment to the vibrator and do not represent the glottal 
vibrations. This conclusion is strengthened by noting the pitch 
of the sound, as made out by counting not the larger but the 
smaller waves, which corresponds to that of the sound given to 
the membrane. I therefore think that argument should be based 
only on records obtained from the phonograph itself, which is 
furnished with a vibrator that will not record its own periodic 
vibrations unless the sound be remarkably intense. In ordinary 
voice production, and in ordinary singing, the vibrator of the 
phonograph faithfully records only the pressures falling upon it — 
no more and no less. 
Having made so large a demand on your patience, I shall not say 
more at present on the curves obtained from musical instruments. 
And now I declare the session 1896-97 to be opened. I hope 
