ABSTRACT
The most notable feature of the scientific study of heat in the eighteenth century is to be found in its experimental work in calorimetry. The eighteenth century also witnessed the beginnings of exact measurements of thermal expansion, and the contributions made by Count Rumford to the study of the relation of heat to work, though his efforts had to wait for their crowning success until Joule carried out his researches in the nineteenth century. The experimental work of the eighteenth century in connection with heat was largely independent of ultimate theories as regards the nature of heat. Heats of combustion and respiration were determined by burning substances, or allowing animals to breathe, in the calorimeter, fresh air being supplied from outside by a suitable arrangement. Count Rumford’s experiments clearly disposed of the caloric theory of heat in favour of a mechanical interpretation.
