Joseph Henry (December 17 1797 - May 13 1878) was a Scottish-American scientist who served as the first Secretary of the Smithsonian Institution. During his lifetime, he was considered one of the greatest American scientists since Benjamin Franklin. While building electromagnets, Henry discovered the electromagnetic phenomenon of self-inductance. He also discovered mutual inductance independently of Faraday, though Faraday was the first to publish his results. Wikipedia
The definitive Wikipedia entry for Joseph Henry. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Joseph_Henry