James Prescott Joule (December 24th 1818, Salford, close to Manchester, England - October 11th 1889, Salts) is a British Physicien . Joule studied the nature of the Chaleur, and discovered its relation with the mechanical work. That led it to the theory of the Conservation of energy (the first law of the Thermodynamique).

He worked with Lord Kelvin to develop the absolute scale of Température (from where the name of the scale). He made observations on the Magnétostriction, and found a relation between the Electric current crossing a resistance and the heat loss, currently called the Loi of Joule.

In 1850, he becomes member of the Royal Society. He was prize winner of the Royal Medal in 1852 and of the Médaille Copley in 1870. The unit of the international System of work, the joule, is baptized with its name.

This pupil of the chemist John DALTON shone as much in the experimentation as by his theories. He took part largely in XIX Century the industrial revolution by developing the machines which revolutionized the work methods and production.

Simple: James Prescott Joule