silsbee: conduction at low temperatures 



601 



solvations have been made on two wires at the same tempera- 

 ture; the table contains the results of practically all such obser- 

 vations that have been published. 6 



TABLE 1 



Critical Values of Current for Various Metals and Temperatures 



Data by H. K. Onnes 



THRESHOLD 

 CURRENT 



THRESHOLD 

 CURRENT DENSITY 



MAX. MAG. FIELD 



Mercury 



Lead. H crit = 600 at 4?2 K 



In the last column is given the maximum value, within the 

 conductor, of the magnetic field due to its own threshold current, 

 that is, the field at the surface of a straight wire or at the inner 

 turns of a coil (the computations for the latter case being cnly 



,; Comm. Phys. Lab. Leiden, No. 133. 



