‎"LE CHATELIER, HENRI LOUIS. - INVENTION OF THE PLATINUM THERMOCOUPLE.‎
‎Sur la variation produite par une élèvation de température, dans la force électromotrice des couples thermo-électriques.‎

‎(Paris, Gauthier-Villars), 1886. 4to. No wrappers. In: ""Comptes Rendus Hebdomadaires des Séances de L'Academie des Sciences"", Tome 102, No 14. Pp. (783-) 834. (Entire issue offered). Le Chatelier's paper: pp. 819-822.‎

Reference : 49879

‎Firs printing of an importent paper in thermometry where he demonstrates that high temperatures could be precisely measured by way of a platinum wire in conjunction with a platinum-rhodium alloy wire.""It is to Henri Louis Le Chatelier th a t we owe the successful practical use of the platinum thermocouple which for many years was in fact known by his name. Among his many activities Le Chatelier was engaged in the study of silicates and cements and needed a reliable method of measuring high temperatures. In 1886 he reported to the Académie des Sciences an investigation on the use of thermocouples for this purpose in which he had tried to verify the parabolic relationships found by Professor T a i t between the electromotive force and the temperature of the hot junction, the cold junction being at 0°C. Using various metals and alloys against platinum, which he calibrated at the known melting points of lead, zinc, aluminium, silver, gold, copper and palladium, he obtainedresults that agreed with his calculations to within 20°C (11). He also came to the conclusion that of the various combinations he had used, platinum against 10 per cent rhodium-platinum gave the most consistent results."" (Donald McDonald and Leslie B. Hunt).Parkinson ""Breakthroughs"", 1885 P.‎