Mr. Bell was very apt to do his experimenting at night, for he was busy
during the day at the Boston University, where he was Professor of Vocal
Physiology, especially teaching his father’s system of visible speech,
by which a deaf mute might learn to talk—quite significant of what Bell
was soon to do in making mute metal talk. For this reason I would often
remain at the shop during the evening to help him test some improvement
he had had me make on the instruments.
One evening when we were resting from our struggles with the apparatus,
Bell said to me: “Watson, I want to tell you of another idea I have,
which I think will surprise you.” I listened, I suspect, somewhat
languidly, for I must have been working that day about sixteen hours,
with only a short nutritive interval, and Bell had already given me,
during the weeks we had worked together, more new ideas on a great
variety of subjects, including visible speech, elocution and flying
machines, than my brain could assimilate, but when he went on to say
that he had an idea by which he believed it would be possible to talk by
telegraph, my nervous system got such a shock that the tired feeling
vanished. I have never forgotten his exact words; they have run in my
mind ever since like a mathematical formula. “_If_,” he said, “_I could
make a current of electricity vary in intensity, precisely as the air
varies in density during the production of a sound, I should be able to
transmit speech telegraphically_.” He then sketched for me an instrument
that he thought would do this, and we discussed the possibility of
constructing one. I did not make it; it was altogether too costly, and
the chances of its working too uncertain to impress his financial
backers—Mr. Gardiner G. Hubbard and Mr. Thomas Sanders—who were
insisting that the wisest thing for Bell to do was to perfect the
harmonic telegraph; then he would have money and leisure enough to build
air castles like the telephone.