Louis Paul Cailletet

CAILLETET, LOUIS PAUL 2-1913 ), French iron master, was born at Chatillon-sur-Seine on Sept. 21, 183 2. He worked in his father's ironworks and later was in charge of the works. He was animated by a love of scientific research. His most important work was on the liquefaction of gases. On Dec. 2, 1877, Cailletet liquefied oxygen at a pressure of 30o atmospheres and at —27° C. The oxygen was obtained in the form of a cloud, but later he repeated his experiments at the Ecole Normale at Paris, when he liquefied hydrogen, nitrogen and air. This work was carried on independently of the work of Pictet on liquefac tion and there was considerable discussion as to which of the two had succeeded first.

Cailletet was the author of a number of papers in

Comptes Rendus and other French scientific periodicals on the liquefaction of gases and the production of low temperatures, on the passage of gases through metals, on manometers for measuring high pres sures, on critical points and on the state of matter at low tempera tures. He interested himself in aeronautics and devised an appa ratus for measuring the height of an aeroplane. Cailletet was a member of the Paris Academy. He died in his native town on Jan. 5, 1913.