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1830, an American, Joseph Henry (1797-1878), demonstrated the potential of Sturgeon's device for long distance communication by sending an electronic current over one mile of wire to activate an electromagnet which caused a bell to strike. Thus the electric telegraph was born. The leading American scientist after Benjamin Franklin until Willard Gibbs, was a professor at Princeton from 1832 to 1846. His chief scientific contributions were in the field of electromagnetism, where he discovered the phenomenon of self-inductance. The unit of inductance, called ``the henry,'' immortalizes his name. Henry is also remembered as the first Secretary of the Smithsonian Institution, where he made extraordinary contributions to the organization and development of American science.
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Surviving Henry electromagnet, which he termed "quantity magnet."
Sketch of "telegraph" Henry showed
his classes at the Albany Academy.