See Also: Inductance
American physicist; born in Albany, N.Y., who lived from 1797 to 1878. A
professor of physics at Albany Academy for six years, and then fourteen years at
Princeton (then the College of New Jersey), it was at these two institutions where
he did much of his great research work. Henry improved the Electromagnet, invented and operated the first electromagnetic Telegraph, and discovered self-In
ductance (see Induction). The unit of inductance is often called the henry in his honor.
Independently of Faraday, Michael he discovered the principle of the induced Current.
The Scientific American of June 1978 pointed out that Henry was the originator of the only practicable method of sending telegraph
signals through long distances, and … he was the first to put into actual
operation a telegraph of this kind. The inventions of Henry are all embodied in the
Morse (see Morse, Samuel Finley Breese) instrument…. (H)ad Congress granted him a patent for his inventions, at the
time of his death he would have enjoyed a monopoly of all the telegraphs,
railway signals, fire alarms and electro-magnetic (see Magnetism) machines of every kind now in the United States, for he was the father of
them all.
Henry also had the exceptional distinction as the first Secretary and Director
of the newly established (1848) Smithsonian Institution.