LE CHATELIER, HENRI LOUIS. - INVENTION OF THE OPTICAL PYROMETER.

Sur la mesure optique des temperatures élevées.

(Paris, Gauthier-Villars), 1892. 4to. No wrappers. In: "Comptes Rendus Hebdomadaires des Séances de L'Academie des Sciences", Tome 114, No 5. Pp. (195-) 254. (Entire issue offered). Le Chatelier's paper: pp. 214-216.

First appearance of the paper in which Le Chevalier describes his invention of the Optical Pyrometer which was the first instrument to measure degrees Celsius over 3000.

"Henri LeChatelier creates a practical optical pyrometer for measuring the temperature of hot bodies from the light intensity in a narrow wavelenght band by optical comparison of an image of the body in question and a glowing filament. He uses an oil lamp, an iris diaphragm, and a red glass filter for narrowing the wavelenght range."(Parkinson).

Parkinson "Breakthroughs", 1892 P.

Order-nr.: 48915