On the Mechanical Equivalent of Heat

London: Richard and John E. Taylor. 1st Edition. Soft cover. Very Good. FIRST EDITION IN ORIGINAL WRAPPERS of Joule's most developed and complete account of the results of his famous "paddle-wheel" experiments; includes his most accurate determination of what would later be known as the "Joule." "Joule began work about 1845 on a fourth method for determining the mechanical value of heat. His latest efforts received a polite but unremarkable reception at the Cambridge meeting of the British Association. This time the experiments involved a paddle wheel placed in a can filled with water. Weights attached over pulleys working in opposite directions communicated motion to the paddle wheel. Joule argued that 'the force spent in revolving the paddle wheel produced a certain increment in the temperature of the water'..." Although Joule's work with the paddle wheel was largely ignored throughout the late 1840's, he continued to work on the experiments and in 1849 "Joule began work in the cellar of the brewery on a fresh set of results (yielding a mechanical equivalent of 772) which Faraday communicated to the Royal Society on 21 June 1849. In 1850 'On the mechanical equivalent of heat' appeared in the Philosophical Transactions; Joule was elected FRS in June of the same year" (Dictionary of National Biography). IN: Philosophical Transactions of the Royal Society... for the Year 1850, Part I, pp. 61-82. London: Richard and John E. Taylor, 1850. Quarto, original wrappers; custom box. Some toning to wrappers, rubbing and chipping to spine, joints reinforced; text extremely clean and largely unopened. Scarce in wrappers.