Claude Servais Mathias Pouillet (February 16, 1791 - 1868) was a French physicist.
Pouillet was born in Cuzance, Doubs, France.
Between 1837 and 1838 he made, independently of John Frederick William Herschel (1792-1871), the first quantitative measurements of the heat emitted by the Sun. His value was circa half the actual one because the level of the atmospheric absorption was uncertain those times, and the problem wasn't solved until 1888 and 1904. With the Dulong-Petit law he wrongly estimated the temperature of the Sun's surface to be around 1800 °C. This value was corrected in 1879 to 5430 °C by Jožef Stefan (1835-1893).
Poillet works include On atmospheric electricity, (London 1832), Éléments de physique expérimentale et de météorologie, (Paris 1856).
Pouillet died in Paris, France.
See also: pyrheliometer, Stefan-Boltzmann law, tangent galvanometer.