Magnetic Permeability r , cj-c., o/ Iron at Low Temperatures. 87 



Fia. 2. 



3,500 



Relation of Permeability 



to 

 Temperature. 



-200-/90-I80-I70-I60-I50-I40-I50-I20-IIO-IOO-90-60-70 -60 -50-40 -50 -ZQ -10 

 Scale of Temperature (Platinum Degrees). 



