262 



JOHNSTON! ELASTIC BEHAVIOR OF METALS 



Qi are given in Landolt-Bornstein-Meyerhoffer Tabellen (2 

 Aufl. p. 470). For some metals more than one value is given, but 

 it is at present impracticable to determine which are most relia- 

 ble; for this reason, the mean value was adopted in all such cases. 

 For the same reason, the general mean value of the density, as 

 given in the tables (pp. 224-9) was taken. The melting points 

 are those now generally adopted. The data and results are 

 brought together in Table 1. 



TABLE 1 

 Lowering of Melting Point of Metals Effected by Unequal Pressure 



The last column of Table 1 contains the values (in atmospheres) 

 of the excess pressure (acting on the solid only) required to cause 

 the metal to melt at 25° ; these were calculated from the expression 



<p 25 = {T x - 298) /AT 7 ! (Ill) 



The metals are arranged in the order of increasing values of <p 

 calculated in this way. It was conjectured that this order might 

 bear some relation to that obtained when these metals are ar- 

 ranged with reference to the relative values of their elastic con- 

 stants and mechanical properties. 



The most obvious mechanical property with which to com- 

 pare the series of <p values is the flow-pressure. This was deter- 



