Joseph Henry
1797–1878, Albany, New York, United States, Washington, D.C., United States
American physicist who advanced electromagnetism through powerful electromagnets, self-induction, and the electric relay; he was the first Secretary of the Smithsonian Institution.
Henry was born in Albany, New York, and began his scientific research while teaching at Albany Academy. He improved electromagnets by winding insulated wire around iron cores and conducted foundational investigations of electromagnetic induction, including self- and mutual induction.
During the 1830s he independently discovered electromagnetic induction and built powerful electromagnets that operated experimental apparatus, including early electric motors. He also became the first Secretary of the Smithsonian Institution; the unit of inductance, the henry, is named for him.
Workplaces: Albany Academy, Princeton University, Smithsonian Institution
United States