Tainter and Bell— Production of Sound by Light. 323 
phragms. The reason rind thin diaphragms of the various 
materials are more effective than masses of the same substan 
ces, appears to be tnat the aneain disturbance produced by 
t is chiefly a surface action, and that the vibration has to 
be transmitted through the mass of the substance in order to 
affect the ear. 
n this account we have endeavored to lead to the ear air 
that is directly in contact with the illuminated surface, by 
throwing the beam of light upon the interior of a tube; and 
very promising results have been obtained. Fig. 11 shows the 
arrangement we have tried. We have heard from interrupted 
sunlight very perceptible musical tones through tubes of ordi- 
nary ‘vulcanized rubber, of brass, and of | These were 
all the materials at hand in tubular form, and we have had no 
opportunity since of extending the observations to other sub- 
stances. * 
id. 
I am extremely glad that I have the opportunity of making 
the first publicati ion of these researches before a scientific 
society, for it is from scientific men that my work of the last 
six years has received its earliest and kindest recognition. I 
gratefully remember the encouragement which I received from 
the lat ute Professor Henry, at a time when the speaking tele- 
phone existed only in theory. Indeed, it is greatly due to the 
stimulus of his appreciation that the telephone became an 
accomplished fact. 
I cannot state too highly also the advantage I derived in pre- 
liminary experiments on sound vibrations in “this building ay 
Professor Cross, and near here from my valued friend 
Clarence J. Blake. When the public were incredulous of the 
possibility of electrical speech, the American Academy of 
Arts and Sciences, the Philosophical Society of W: ashington, 
and the Essex Institute of Salem, recognized the reality of the 
results and honored me by their ‘congratulations. The public 
interest, I think, was first awakened by the judgment of the 
*Ar a ical i can be heard by rah tebia the intermittent beam of light into 
the ear itself. experiment was at first unsuccessful on account of the posi- 
tion in which Ap ear was held. 
