The international temperature scale

In 1911, the directors of the national laboratories of Germany, Great Britain, and the United States agreed to undertake the unification of the temperature scales in use in their respective countries. This endeavor was approved formally in 1913 by the Fifth General Conference of Weights and Measures, and in 1921 the Sixth General Conference voted to expand the field of activities of the International Conllnittee and International Bureau by including physical constants, such as standard temperatures, and the coordination of results obtained in other institutions. This action was duly ratified by the several governments adhering to the conference. Finally, in 1927, the Seventh General Conference, representing 31 nations, on the recommendation of the three laboratories above mentioned, which had consulted with the Leiden Cryogenic Laboratory as to low temperatures, adopted unanimously the following resolution, proposed by the International Committee of Weights and Measures: Le Comite, reconnaissant l 'importance pratique de la representation d'une echelle thermometrique internationale, recommande a la Conference d'accepter, a titre provisoire, les reperes de temperature, les formules d'interpolation et les methodes de mesure proposes d 'un commun accord par les trois laboratoires nationaux d ' Allemagne, des Estats-Unis d' Amerique, et de Grande-Bretagne. Le Comite recommande aussi que Ie texte annexe soit maintenu a l'etude dans Ie programme des Conferences speciales de Thermometrie qui seront tenues so us ses auspices. The English text is as follows : TEXT CONCERNING THE ADOPTION OF AN INTERNATIONAL TEMPERATURE SCALE SUBMITTED FOR DISCUSSION BY THE BUREAU OF STANDARDS, NATIONAL PHYSICAL LABORATORY, AND PHYSIKALISCH-TECHNISCHE REICHSANSTALT.