Joseph Henry

Joseph Henry

Joseph Henry (December 17 1797 – May 13 1878) was an American scientist. While building electromagnets, he discovered the electromagnetic phenomenon of self-inductance. He also discovered mutual inductance, independently of Faraday, but Faraday was the first to publish his results. His work on the electromagnetic relay was the basis of the electrical telegraph, jointly invented by Morse and Wheatstone.

The SI unit of inductance, the henry, is named after him.

Career

• 1826 - Professor of Mathematics and Natural Philosophy at Albany Academy, New York.
• 1832 - Professor at Princeton.
• 1835 - invents the electromechanical relay.
• 1846 - First secretary of the Smithsonian Institution.
• Second president of National Academy of Sciences.

See also

• Electromagnetism: Henry (Scientific units named after people), Multiple coil magnet
• Lists: List of physicists, Timeline of invention, Timeline of communication technology, List of physics topics
• Other: Gasport, New York, American Philosophical Society