Thursday, October 13, 2011

Joseph Henry (1797-1878) was born near Albany, New York. His ambition was to become an actor until by chance at the age of 16 he happened to read a book of science, which caused him to devote his life to the acquisition of knowledge. That event turns out to be the beginning of Henry’s rise as the leading American scientist after Benjamin Franklin and until Willard Gibbs.

Education and Research

Joseph Henry enrolled in the Albany Academy and upon graduation became a teacher there. Henry’s research led him to experiment with magnets. He actually discovered electromagnetic induction in America about the same time Michael Faraday discovered it in England in 1831. Faraday was given the credit because his results were published first.

In 1832, he joined the faculty of the college of New Jersey, now Princeton and in 1846 joined the Smithsonian Institution. 
Joseph Henry
Joseph Henry

Joseph Henry however took active interest in electromagnetism. He went beyond Faraday and continued to research into induction. He used electromagnets to build philosophical toys, which foreshadowed the electric motor and telegraph.

More importantly, Henry became famous as the discoverer of the inductance (also called self-inductance) of a coil and as a developer of the powerful electromagnets capable of lifting thousands of pounds of weight. He also developed a device for controlling circuits known as a “relay”.


Joseph Henry was known as America’s foremost 19th century physicist and the first secretary general of the newly formed Smithsonian Institution.

In 1893, the standard electrical unit of inductive resistance, the henry, was named after him.

1 comment:

BoyGR said...

nice post man... keep creatif and powerful


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I am a Professional Electrical Engineer with a Masters Degree in Business Administration. My interest is in Power Quality, Diagnostic Testing and Protective Relaying. I have been working in an electric distribution utility for more than a decade. I handle PQ studies, power system analysis, diagnostic testing, protective relaying and capital budgeting for company projects.