Engineering Hall of Fame

Joseph Henry
The accomplishments and life of Joseph Henry, Jr. 1797-1878

Joseph Henry was the pioneer of the first real electromagnet and his work led to the electric motor telegraph and more. He led a fundamental foundation for all electrical inventions. Others who came after used his work to create the first powerful electric motors, telegraph, generators, and more. Joseph Henry and Michael Faraday worked on similar technologies in different locations.

Invention of the Electromagnet:

1820 - Hans Christian Orsted discovered that electric currents create magnetic fields
1824 - William Sturgeon was the first to take an varnished iron core and wrap it with bare copper wire. When he energized it became magnetized for a moment, then lost magnetism when the current escaped into the iron core. He could not do a multi-layered wrap, which did not allow the magnet to be very strong.
1827 - Joseph Henry discovers that it is necessary to use isolated wires (copper wrapped in silk) to make the wrap around the iron core, this is very important and allows the magnet to hold a magnetic field. The electromagnet has remained basically the same ever since.

1830 - Joseph Henry moves from Albany Academy to Princeton, NJ. Princeton funds a trip to England where Henry meets his contemporary Michael Faraday.

See the video below about it:

 

Dr. Frank Wicks talks about Michael Faraday and Joseph Henry and their magnets

Biography

Joseph Henry (December 17, 1797 - May 13, 1878) was an American scientist and engineer. While building electromagnets, he discovered the electromagnetic phenomenon of self-inductance. He also discovered mutual inductance, independently of Michael Faraday, but Faraday was the first to publish his results. His work on the electromagnetic relay was the basis of the electrical telegraph, jointly invented by Morse and Wheatstone. The SI unit of inductance, the henry, is named after him.

Early Years Joseph Henry was born on December 17th, 1797 in Albany, NY to two immigrants from Scotland, Ann Alexander Henry and William Henry. His parents were poor and Joseph’s father died while he was still a young boy. So, for the rest of his childhood, Joseph lived with his grandmother in Galway, NY. He attended a school which would later be named Joseph Henry Elementary School in his honor. After school, he worked at a general store, and later, at the age of thirteen, he went to work as an apprentice watchmaker and silversmith. Joseph’s first love was theater and he came very close to becoming a professional actor. His interest in science was piqued at the age of sixteen, by a book of lectures on scientific topics titled Popular Lectures on Experimental Philosophy. And, in 1819, persuaded by some influential friends to pursue a more academic career, he entered Albany Academy, where he was given free tuition. He was poor so, even with free tuition, Joseph Henry had to support himself with teaching and private tutoring positions. Initially, he intended to go into the field of medicine, but, in 1824, he was appointed an assistant engineer for the survey of State road, being constructed between the Hudson River and Lake Erie, a distance of 300 miles. From then on, he was inspired to a career in engineering.

Electromagnetism Work At The Albany Academy

Joseph Henry excelled at his studies (so much so, that he would often be helping his teachers teach science) and, by 1826, he was appointed Professor of Mathematics and Natural Philosophy at The Albany Academy in Albany, New York. Some of Henry's most important research was conducted in this new position. Joseph’s curiosity about terrestrial magnetism lead him to experiment with magnetism in general.

Photo of one of Henry's earliest magnets attached what is probably a battery. This photo was taken with E.W. Rice Jr. holding it in the 1920's.

The bell is part of one of J. Henry's early experiments, more research is needed to find out what was the nature of this experiment. He may of used the magnet to pull the striker and ring the bell.

He was the first to tightly coil insulated wire around a ferrous core to make an extremely powerful electromagnet, improving on William Sturgeon’s electromagnet, which used loosely coiled uninsulated wire. Using this technique, he built the most powerful electromagnet at the time, for Yale. He also showed that, when making an electromagnet using just two electrodes attached to a battery, it is best to wind several coils of wire in parallel, but, when using a set up with multiple batteries, there should be only one single, long coil used. The latter made the telegraph feasible.

The magnet above was probably overheated and caused the damage. He built a frame and apparatus for lifting using the world's most powerful electromagnet at the time, it was demonstrated at the Albany Academy in Albany, New York.

Henry's Electric Motor

He took what he had learned a step further and, in 1831, created one of the first machines to use electromagnetism for motion. This was the one of the earliest ancestors of the modern DC motor. It didn’t make use of rotating motion, but was merely an electromagnet perched on a pole, rocking back and forth. The rocking motion was caused by on of the two leads on both ends of the magnet rocker touching one of the two battery cells, causing a polarity change, and rocking the opposite direction until the other two leads hit the other battery. Henry's work on motors allowed Thomas Davenport to invent the first real electric motor in 1834. Davenport used his motor to operated a small model car and train. This helped lead to street cars developed by Frank Sprague and the Electric Car.

Joseph Henry's oscillating beam motor, photo from the Smithsonian.

 

Below a video on Joseph Henry and his link to superconductivity: (from our YouTube Channel)

 

Below a film from 1932 of AC pioneer Elihu Thomson and E. W. Rice (2nd pres. of GE) who mention Joseph Henry in a statement about the forefathers of electricity.

 

The Yale Magnet, photo by the Smithsonian.

Joseph Henry Career Timeline :
1826- Professor of Mathematics and Natural Philosophy at Albany Academy, New York.
1832 - Professor at Princeton.
1846- First secretary of the Smithsonian Institution.
Second president of National Academy of Sciences.

Next: Henry layed the ground work for the invention of the electric motor by Thomas Davenport.

Volunteer! Help us improve this webpage by conducting your study of
Joseph Henry at the Edison Tech Center.

 

Article by Edwin D. Reilly Jr. in 2007, modified by M.Whelan in 2010.

Sources:
-Electrical Pioneers of America, Their Own Words. Edited by Stephen P. Tubbs, M.Sc.P.E. 2003.
-Joseph Henry, Wikipedia
-Library of Congress, Thomas Davenport papers
-The Blacksmiths Motor, by Frank Wicks Jr. ASME
-National High Magnetic Field Laboratory, ww.nhmfl.gov
-Thomas Davenport, Wikipedia
-Getting Electricity to Work for Man: http://www.hbci.com/~wenonah/history/edpart2.htm-
-Wired.com
-Deutsches Museum

Photos:
Smithsonian
Schenectady Museum

Videos:
Edison Tech Center

 

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