Joseph Henry, an American physicist who carried out early experiments in electrical induction, was born in Albany, New York, in 1797. The son of a laborer, Henry had little schooling and was forced to go to work at a very young age. After working his way through Albany Academy to study medicine, then engineering, Henry became professor of mathematics and physics in 1826. He later became professor of natural philosophy at New Jersey College (now Princeton University).
In 1848, Henry became the first director of the Smithsonian Institute, where he introduced a weather-forecasting system based on meteorological information received by the electric telegraph. He was also the first president of the Academy of Natural Science, a position he held until his death in 1878.
Many of Henry's early experiments were with electromagnetism. He improved the electromagnet of William Sturgeon and made one of the first electromagnetic motors. By 1830, Henry had made powerful electromagnets by using many turns of fine insulated wire wound around iron cores. He discovered the phenomenon of self-induction but failed to publish his findings; as a result, credit was given to Michael Faraday.
Henry's contribution to science was ultimately recognized: in 1893 the unit of inductance was named the henry.