19th Century Pioneers

Joseph Henry  (1797 – 1878)

The American Physicist that discovered the electrical property of self inductance independently of the English scientist Faraday.  Henry made design improvements with electromagnets that greatly increased their ability to lift magnetic material.  He insulated the wire instead of the iron core.  A magnet that he made for Yale College could support a weight of 2086 lbs.

The unit of inductance, the Henry (h) was named in his honor.  If a current changing at the rate of one ampere per second induces an electromotive force (emf) of  one volt, then the circuit has an inductance of one Henry.

He had diplomatic skills as well as scientific knowledge and became the first secretary of the Smithsonian (1846 -1878).

Joseph Henry was a technical advisor to President Lincoln during the Civil War.