449 



') The fwo first temperatures in this table are derived graphically by means of 

 a formula slightly differing from that given in Comm. No. 159 in the „Discussion". 



2) Referring to § 3 concerning the heat conductivity of helium vapour, yet the 

 threshold values might have been found greater, when the resistances would have 

 been surrounded directly by liquid helium. [Note added in the translation]. 



29* 



