Michael Faraday
1791-1867
Faraday was an English
bookbinder who became interested in
electricity. He obtained an
assistantship in
Davy's lab, then began to
conduct his own experiments. He wrote a review article on current
views about
electricity and
magnetism in 1821, for which he
reproduced
Oersted's experiment. He was
one of the greatest experimenters ever. Because he was self trained,
however, he had no grasp of mathematics and could therefore not
understand a word of
Ampère's papers. In the course
of his experiments, Faraday discovered that a suspended magnet would
revolve around a current bearing wire, leading him to propose that
magnetism was a circular force. He also discovered magnetic optical
rotation, invented the
dynamo
(a
device capable of converting electricity to motion) in 1821,
discovered electromagnetic induction in 1831, and devised the laws
of chemical electrodeposition of metals from solutions in 1857. |
He first suggested that current produces a electric "tension" which produced an "electrotonic state," or polarization of matter molecules, and was responsible for transmitting the electric force. He experimented with dielectrics in a capacitor.
After further
experimentation, he abandoned the concept of electrotonic forces in
favor of "lines of force." He maintained that these lines could be
made visible in a
magnet using iron filings.
Faraday was an advocate of the law of
conservation of energy,
believing that possibility of "the production of any one [power]
from another, or the conversion of into another."