Born Jan. 26, 1799, in Paris; died there Jan. 28, 1864. French physicist. Member of the Paris Academy of Sciences (1858).
Clapeyron graduated from the Ecole Polytechnique in Paris in 1818. From 1820 to 1830 he worked in St. Petersburg at the Institute of Railroad Engineers. Upon returning to France, he became a professor at the School of Bridges and Roads in Paris. In 1834, Clapeyron took note of S. Carnot’s work, retraced his reasoning, and, using the graphic method for the first time in thermodynamics, gave Carnot’s results geometric form. Studying the Carnot cycle, he derived the equation of state of an ideal gas. He also formulated the dependence of the melting and boiling points on temperature.