TABLE 236. 

 MELTING-POINTS OF THE CHEMICAL ELEMENTS. 



2I 7 



The metals in heavier type are often used as standards. 



The melting-points are reduced as far as possible to a common temperature scale which is the 

 one used by the United States Bureau of Standards in certifying pyrometers. This scale is de- 

 fined in terms of Wien's law with Cg taken as 14500, and on which the melting-point of platinum 

 is 1755 C (Nernst and Wartenburg, 1751 ; Waidner and Burgess, 1753 ; Holborn and Valentiner, 

 1770; see C. R. 148, p. 1177, 1909). Above nooC, the temperatures are expressed to the 

 nearest 5 C. Temperatures above the platinum point may be uncertain by over 50 C. 



SMITHSONIAN TABLES. 



