accomplishments and life of Joseph Henry, Jr. 1797-1878
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:
- 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
(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.
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 Josephs 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. Josephs 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.
Josephs 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 Sturgeons 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.
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,
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 didnt 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.
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
1826- Professor of Mathematics and Natural Philosophy at Albany Academy,
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
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.
-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
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-
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