Bell, Alexander Graham
Born in Edinburgh in 1847, he studied at Edinburgh and London, and worked as assistant to his father in teaching elocution. In 1870 he went to Canada, and later moved to the USA and became professor of vocal physiology at Boston, devoting himself to the teaching of deaf-mutes and to spreading his father's system of "visible speech'.
Bell carried out experiments to determine how vowel sounds are produced. A book, decsribing experiments in combining the notes of electrically-driven tuning forks to make vowel sounds, gave him the idea of telegraphic speech.
Later, during experiments with his assistant Watson with the telegraph, Bell reasoned that it would be possible to pick up all sounds of the human voice on the harmonic telegraph. After tedious experimentation the Bell telephone carried its first intelligible sentence in the spring of 1876.
He formed the Bell Telephone Company and in 1880 he established the Volta Laboratory. He also invented the photophone (1880) and the graphophone (1887). After 1897 his principal interest was in aeronautics.
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