had a great
horror that his ideas might be stolen and was very nervous over any
possible intrusion into his precious workshop. Only the members of
the Sanders family were allowed to enter the basement. He was equally
cautious in purchasing supplies and equipment lest his very purchases
reveal the nature of his experiments. He would go to a half-dozen
different stores for as many articles. He usually selected the night
for his experiments, and pounded and scraped away indefatigably,
oblivious of the fact that the family, as well as himself, was sorely
in need of rest.

"Bell would often awaken me in the middle of the night," says Mr.
Sanders, "his black eyes blazing with excitement. Leaving me to go
down to the cellar, he would rush wildly to the barn and begin to send
me signals along his experimental wires. If I noticed any improvement
in his apparatus he would be delighted. He would leap and whirl around
in one of his 'war-dances,' and then go contentedly to bed. But if
the experiment was a failure he would go back to his work-bench to try
some different plan."

In common with other experimenters who were searching for the
telephone, Bell was experimenting with a sort of musical telegraph.
Eagerly and persistently he sought the means that would replace the
telegraph with its cumbersome signals by a new device which would
enable the human voice itself to be transmitted. The longer he worked
the greater did the difficulties appear. His work with the deaf and
dumb was alluring, and on many occasions he seriously considered
giving over his other experiments and devoting himself entirely to the
instruction of the deaf and dumb and to the development of his system
of making speech visible by making the sound-vibrations visible to the
eye. But as he mused over the difficulties in enabling a deaf mute to
achieve speech nothing else seemed impossible. "If I can make a deaf
mute talk," said Bell, "I can make iron talk."

One of his early ideas was to install a harp at one end of the wire
and a speaking-trumpet at the other. His plan was to transmit
the vibrations over the wire and have the voice reproduced by the
vibrations of the strings of the harp. By attaching a light pencil
or marker to a cord or membrane and causing the latter to vibrate by
talking against it, he could secure tracings of the sound-vibrations.
Different tracings were secured from different sounds. He thus sought
to teach the deaf to speak by sight.