James Prescott Joule was born on December 24, 1818 in Salford, Lancashire. His father, Benjamin Joule, was a wealthy brewer. Joule received his early education at home with a tutor until 1834 at which time he attended the Manchester Literary and Philosophical Society. Here he studied under the famous chemist, John Dalton. Dalton only taught him for two years before retiring due to a stroke. In spite of the short contact time, Dalton made a big impression on Joule and inspired his interest in science.
Joule took over the running of his father’s brewery until 1854, when it was sold. Science, at this time, was mostly a hobby, but he also applied it to the business of brewing. He published papers on electricity and attempted to replace the brewery’s steam engines with electric motors. In 1840, he elucidated Joule’s Laws and attempted to present his ideas to the Royal Society. They considered him a bit of a provincial and did not take his ideas seriously.
Joule continued his work with economics in mind. He determined that burning a pound of coal could produce as much energy as a pound of zinc in an early battery. His studies let him to reject the caloric theory, in place since Antoine Lavoisier’s work of the 1700s. He had found that work can in fact be converted to heat and heat to work. He calculated very precisely the mechanical equivalent of heat, the work required to raise the temperature of a pound of water by one degree. Since Joule had no position in academia, he had a hard time convincing anyone of his ideas. His presentation to the British Association for the Advancement of Science in 1843 was met with complete silence.
Joule began to create a mechanical demonstration of his ideas and in the process made some of the most precise measurements ever taken. He could measure temperature to 1/200 of a degree. Some of the resistance he met was due to disbelief of his measurements.
In 1847, Joule married Amelia Grimes. On their honeymoon, he and William Thomson, later to be Lord Kelvin, performed an experiment in which they measured the temperature of water at the top and bottom of the Cascade de Sallanches waterfall. Thomson and Joule continued to collaborate for many years after.
Joule eventually became a fellow of the Royal Society and was honored with the Royal and Copley medals. He also received honorary degrees from several universities. Joule died on October 11, 1889 in Sale, Cheshire.
Image: James Joule - Physicist.