lopment of the telegraph. Now he was destined to aid Bell, as he
had aided Morse a generation earlier. The two men spent a day over the
apparatus which Bell had with him. Though Professor Henry was fifty
years his senior and the leading scientist in America, the youth was
able to demonstrate that he had made a real discovery.

"You are in possession of the germ of a great invention," said
Henry, "and I would advise you to work at it until you have made it
complete."

"But," replied Bell, "I have not got the electrical knowledge that is
necessary."

"Get it," was Henry's reply.

This proved just the stimulus Bell needed, and he returned to Boston
with a new determination to perfect his great idea.

Bell was no longer experimenting in the Sanderses' cellar, having
rented a room in Boston in which to carry on his work. He had also
secured the services of an assistant, one Thomas Watson, who received
nine dollars a week for his services in Bell's behalf. The funds
for this work were supplied by Sanders and Hubbard jointly, but they
insisted that Bell should continue his experiments with the musical
telegraph. Though he was convinced that the opportunities lay in the
field of telephony, Bell labored faithfully for regular periods with
the devices in which his patrons were interested. The remainder of his
time and energy he put upon the telephone. The basis of his telephone
was still the disk or diaphragm which would vibrate when the
sound-waves of the voice were thrown against it. Behind this
were mounted various kinds of electro-magnets in series with the
electrified wire over which the inventor hoped to send his messages.
For three years they labored with this apparatus, trying every
conceivable sort of disk. It is easy to pass over those three years,
filled as they were with unceasing toil and patient effort, because
they were drab years when little of interest occurred. But these were
the years when Bell and Watson were "going to school," learning how
to apply electricity to this new use, striving to make their apparatus
talk. How dreary and trying these years must have been for the
experimenters we may well imagine. It requires no slight force of will
to hold oneself to such a task in the face of failure after failure.

By June of 1875 Bell had completed a new Instrument. In this the
diaphragm was a piece of gold-beater's skin, which Bell had selected
as most closely resembling the drum in the human ear. This was