Rumford's thermodynamics experiment. Count Rumford (1753-1814, centre), born Benjamin Thompson, was an Anglo-American physicist and reformer. This artwork shows one of his experiments on the heat that is generated when boring a cannon. Rumford suggested that the heat was a result of motion and the resulting friction. These ideas fundamentally disagreed with the favoured calorific theory, where heat was thought to be a material substance. Rumford's ideas were eventually vindicated. These experiments were carried out at the Munich Arsenal in Germany, and Rumford announced his theory in 1798. He was knighted by King George III in 1784, and created a count of the Holy Roman Empire in 1791. From Physique Populaire (E. Desbeaux, 1891).