DUHAMEL, JEAN-MARIE-CONSTANT

born Feb. 5, 1797, Saint-Malo, Fr. died April 29, 1872, Paris French mathematician and physicist who proposed a theory dealing with the transmission of heat in crystal structures based on the work of the French mathematicians Jean-Baptiste-Joseph Fourier and Simon-Denis Poisson. Duhamel entered the cole Polytechnique in 1814 but was forced to return to Rennes in 1816. In 1830 he began teaching analysis at the cole Polytechnique, a position he held for 39 years. While at the cole he engaged in acoustical studies involving vibrating strings and the vibration of air in cylindrical and conical pipes, as well as the physics of harmonic overtones. Duhamel also researched the distribution of heat in a solid with a variable boundary temperature, which led to a principle in partial differential equations known as Duhamel's principle. He also taught at the cole Normale Suprieure and at the Sorbonne. He was a member of the French Academy of Sciences.