Joseph Henry was an important American scientist of the 19th century, the first Director of the Smithsonian Institution (1846), and one of the founding members of the National Academy of Science. Henry independently discovered electromagnetic self-induction in 1831, however the credit goes to Michael Faraday for being first. Henry is also credited with the invention of an electric motor, however, again not the first. In 1830, Joseph Henry, demonstrated the potential of a William Sturgeon device for long distance communication by sending an electronic current over one mile of wire to activate an electromagnet which caused a bell to strike. Thus the electric telegraph was born, however, other inventors made a commercial success of that invention.

Joseph Henry - Fathers of Electricity
Joseph Henry began a wide series of experiments and investigations which touched so many phases of the great problem of electricity including: the phenomena of self induction and mutual induction. Part 2: Joseph Henry - Basis For the Electric Telegraph, Magnetic Engine, Smithsonian Institution Part 3: Joseph Henry - Other Achievements

Papers of Joseph Henry
The Joseph Henry Papers Project documents the life of Joseph Henry (1797-1878), American scientist and the first Director of the Smithsonian Institution. Joseph Henry's pioneering work in electricity and magnetism helped bring about the invention of the telegraph, the electric motor, and the telephone.

"But for Joseph Henry, I would never have gone ahead with the telephone." - Alexander Graham Bell

In 1893, Joseph Henry's name was given to the standard electrical unit of inductive resistance, the "henry."

Joseph Henry
Joseph Henry chief scientific contributions were in the field of electromagnetism, where he discovered the phenomenon of self-inductance.

Joseph Henry 1797-1878
Biography and extracts of writing.

Related Information
Magnetic Fields - History of Magnets and Electromagnetism
History of the discovery of electromagnetism by Oersted and Ampere.
Smithsonian Institution