Claude Pouillet

He studied sciences at the École normale supérieure (Paris), and from 1829 to 1849 was associated with the Conservatoire national des arts et métiers, first as a professor, and beginning in 1832, an administrator. After the death of Pierre Louis Dulong in 1838, he attained the chair of physics at the Faculty of Sciences. For a brief period of time, he was chair of physics at the École Polytechnique (1831), where he was succeeded by César Despretz in 1831 and Gabriel Lamé in 1832. In 1852, he was compulsorily retired from the Faculty of Sciences because he refused to swear an oath of allegiance to the imperial government that took power in late 1851. == Scientific research ==

The Pouillet effect was named after the phenomenon that he published in 1822 on the heat produced by the wetting of dry sand. He developed a pyrheliometer and made, between 1837 and 1838, the first quantitative measurements of the solar constant. His estimate was 1228 W/m2, very close to the current estimate of 1367 W/m2. Using the Dulong-Petit law inappropriately, he 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). He published works on optics, electricity, magnetism, meteorology, photography and photometry. In the field of optics he conducted investigations of diffraction phenomena. In his studies of electricity, he designed sine and tangent galvanometers. His acclaimed textbook on physics and meteorology, Éléments de physique expérimentale et de météorologie, was published in four parts. Also, it was translated into German by Johann Heinrich Jakob Müller, and published with the title, Lehrbuch der Physik und Meteorologie. Svante Arrhenius (1896) cited a great deal of Pouillet's work. == Bibliography ==