Philosophical transactions of the Royal Society of London v.88 (1798)

151. Heat This article laid the foundation for the measurement of heat and its equivalence to mechanical energy. Rumford, born in America, exiled to Britain, and employed in Bavaria, observed the heating of water in which cannon barrels were being bored out. His realization that the amount of heat produced only depended on the friction of the machines destroyed the old concept of "caloric" to explain heat. 
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151. Heat

This article laid the foundation for the measurement of heat and its equivalence to mechanical energy. Rumford, born in America, exiled to Britain, and employed in Bavaria, observed the heating of water in which cannon barrels were being bored out. His realization that the amount of heat produced only depended on the friction of the machines destroyed the old concept of "caloric" to explain heat.