deaf-mutes. He opened a school of "Vocal Physiology," and his
success in his chosen field brought him into association with the
people who afterward played an important part in the development
of the telephone. Not a single element of romance was lacking in
Bell's experience; his great invention even involved the love
story of his life. Two influential citizens of Boston, Thomas
Sanders and Gardiner G. Hubbard, had daughters who were deaf and
dumb, and both engaged Bell's services as teacher. Bell lived in
Sanders's home for a considerable period, dividing his time
between teaching his little pupil how to talk and puttering away
at a proposed invention which he called a "harmonic telegraph."
Both Sanders and Hubbard had become greatly interested in this
contrivance and backed Bell financially while he worked. It was
Bell's idea that, by a system of tuning different telegraphic
receivers to different pitches, several telegraphic messages
could be sent simultaneously over the same wire. The idea was not
original with Bell, although he supposed that it was and was
entirely unaware that, at the particular moment when he started
work, about twenty other inventors were struggling with the same
problem. It was one of these other twenty experimenters, Elisha
Gray, who ultimately perfected this instrument. Bell's researches
have an interest only in that they taught him much about sound
transmission and other kindred subjects and so paved the way for
his great conception. One day Hubbard and Sanders learned that
Bell had abandoned his "harmonic telegraph" and was experimenting
with an entirely new idea. This was the possibility of
transmitting the human voice over an electric wire. While working
in Sanders's basement, Bell had obtained from a doctor a dead
man's ear, and it is said that while he was minutely studying and
analyzing this gruesome object, the idea of the telephone first