The awarding of the Copley Medal and the ‘discovery’ of the law of conservation of energy: Joule, Mayer and Helmholtz revisited

Abstract

This article analyses the awarding of the Royal Society's Copley Medal to James Prescott Joule (1870), Julius Robert Mayer (1871) and Hermann Helmholtz (1873) in the wake of the establishment of the law of conservation of energy during the 1850s and 1860s. It seeks to reconstruct the context in which the awards occurred, emphasizing at once a combination of individual scientific achievement, advocacy on behalf of Joule's supporters, nationalism, and the special role that Helmholtz played thanks to the strong social relationship that he had developed with the British scientific elite in the two decades before receiving his award, the last of the three. The award in turn strengthened that relationship, as the great subject of discussion in physics now gradually turned from thermodynamics to electromagnetism and to reaching practical agreements in electrical metrology between the British, the Germans and others.