James Prescott Joule
James Prescott Joule was an English physicist who studied the nature of heat and established its
relationship to mechanical work. He therefore laid the foundation for the theory of conservation
of energy, which later influenced the First Law of Thermodynamics. He also formulated the
Joule’s laws which deal with the transfer of energy.
Early Life and Education:
Born in Salford, Lancashire on December 24, 1818, James Prescott Joule’s father was a rich
brewer. Joule was mostly homeschooled. He studied arithmetic and geometry under John Dalton
at the Manchester Literary and Philosophical Society. He was later taught by famous scientist
and lecturer, John Davies.
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Contributions and Achievements:
James Prescott Joule analyzed the nature of heat, and established its relationship to mechanical
energy. His efforts had a profound influence on the theory of conversation of energy (the First
Law of Thermodynamics). He collaborated with Lord Kelvin on the formulation of the absolute
scale of temperature, and carried out extensive research on magnetostriction; a property of
ferromagnetic materials that makes them modify their shapes when exposed to a magnetic field.
Joule was the first scientist to identify this property in 1842 during an experiment with a sample
of nickel. He established the relationship between the flow of current through a resistance and
the heat dissipated, which was later termed as Joule’s law. He is also credited with the first-ever
calculation the velocity of a gas molecule. The derived unit of energy or work, the Joule, is
named after him.
Joule was elected to the Royal Society of London and was given a Copley award. He also served
as the president of the British Association for the Advancement of Science.
Later Life and Death:
James Prescott Joule died on October 11, 1889 in Sale, Greater Manchester, England. He was 70
years old.
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