JOURNAL 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. II, APRIL 4, 1912 No. 7 



PHYSICS. — The nitrogen thermometer scale from 300° to 630°, 

 with a direct determination of the boiling point of sulfur. 

 Arthue L. Day and Robert B. Sosman. Geophysical 

 Laboratory, Carnegie Institution. To appear in full in the 

 American Journal of Science. 



1. PURPOSE AND PLAN OF THE INVESTIGATION 



In our recent investigation of the fundamental high tempera- 

 ture scale with the gas thermometer 1 attention was chiefly directed 

 to the temperature region above 1000°. The lower temperatures 

 had been determined with considerable accuracy in an investiga- 

 tion undertaken in the Reichsanstalt 2 some years earlier (1900) 

 and there was no reason to suspect in it any uncertainty of greater 

 magnitude than the errors of observation determined at that time 

 (2° to 3°). Our determinations (1911) of the temperatures below 

 1000° came out about 1° lower than those of the Reichsanstalt 

 scales. 



The situation from our viewpoint at the time of publication of 

 our final results (1911) was accurately summed up in one of our 

 closing paragraphs as follows: 



1 Preliminary publications : — Day and Clement: Physic. Rev., 24: 531, (Abstract) 

 1907. Day and Clement: Am. J. Sci. (4), 26: 405-463. 1908. Day and Sosman,, 

 Am. J. Sci. (4), 29: 93-161. 1910. R. B. Sosman: Am. J. Sci. (4), 30: 1-15. 1910.' 



Final publication: — Day and Sosman: Carnegie Institution Pub. No. 157. 1911. 



2 Holborn and Day: Ann. Physik. (4), 2: 505-545. 1900. Am. J. Sci. (4), 10: 

 171-206. 1900. 



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