Claude Pouillet

Claude Servais Mathias Pouillet ( born February 16, 1791 in Cusance, Doubs, † June 14, 1868 in Paris) was a French physicist.

Pouillet attended the École normale supérieure in 1811 in Paris, where he Repetent and Maitre de Conférences soon. He then was appointed Professor of Physics at the Collège royal de Bourbon and in 1829 appointed Assistant Director of the Conservatory of Arts and Industry. 1831 he was appointed director of this institution.

Is named as the physical effect Pouillet exothermic reaction which occurs when powder is wetted by a liquid. First observed in 1802 by Leslie on dry sand and water, described Pouillet 1822 this phenomenon.

As a supporter of the July Monarchy Pouillet also one of the representatives of the deputies who supported the ministerial policy. After the February Revolution of 1848 he retired from political life and put after the coup d'etat of December 2, 1851 and its other offices down.

Since 1837 Pouillet was a member of the Academy of Sciences. He worked mainly optical, thermodynamic and electrical issues. Famous are his Éléments de physique et de expérimentale météorologie ( 2 vols, Paris 1827), German ed in 1842 by Johann Heinrich Jacob Müller, 1875. by Leopold Pfaundler, and Notions générales de physique et de météorologie (Paris 1850).

Pouillet measures in 1838 with his invented " Pyrheliometer " the radiated heat from the sun. His instrument converts the radiation energy into heat energy. This can be measured thermometric and it may indirectly the solar constant to be determined. Pouillet established in 1337 " Thermal Units per second," which is the correct value of the solar constant of 1.36 kW / m good. Since the correct Stahlungsgesetze at that time were not yet known, the calculated value of Pouillet for the surface temperature of the sun (1700 ° C) deviates greatly from the actual value ( 6058 ° C).