Mechanical Equivalent of Heat. JOULE, JAMES PRESCOTT. 1818-1889. On the calorific effects of magneto-electricity, and on the mechanical value of heat. London, Edinburgh and Dublin: Philosophical Magazine and Journal of Science, 3rd series, 23 (1843) 8vo (215 x 133 mm). Engraved frontispiece, text illustrations. 19th century half calf, marbled boards, light rubbing. Minor foxing but very good. Binder's stamp on rear paste-down. FIRST EDITION, complete series of three parts. Dibner, Heralds of Science 158. 'Experimental proof of the mechanical equivalent of heat for physical phenomena' (Printing and the Mind of Man p. 196). Joule demonstrated that the conversion of heat into force, and vice versa, takes place at a fixed rate. This discovery led to two conclusions: first, that heat is a form of energy; and second, that within a given system, the sum total of energy is both constant and convertible. Joule's work, along with that of Mayer and Helmholtz, was fundamental to the establishment of the principle of the conservation of energy. DSB; Norman 1179. For further information on this lot please visit Bonhams.com For further information about this lot please visit the lot listing