﻿42 Dr. Ashworth on Magnetic Temperature Coefficients 



-180° C. to 1200° C. The curves show that there is in 

 low fields a maximum intensity for some intermediate tem- 

 perature, but in the highest field employed 400 (c.G.s. units) 

 this maximum disappears entirely in iron, is nearly obliterated 

 in nickel, and becomes less pronounced in cobalt. There is 

 little doubt that the curves would decline smoothly from the 

 lowest to the highest temperature in very strong fields. 

 From the curves traced by Honda and Shimizu I have 

 constructed Table II., which shows again that the rate of 

 diminution of magnetic intensity as the temperature rises is 

 greatest in nickel and least in cobalt. 



Table II. 



Relation of Magnetic Intensity to Temperature. Honda and 

 Shimizu's Observations in a field of 400 C.G.s. units. 



Nickel. 



Iron. 



Cobalt. 



Temp. C°. 



6/9,. 



I/Io- 



Temp. C°. 



9/9 v 



I/I - 



Temp. C°. 



6/9,. 



I/Io- 







•45 



•95 







•25 



•98 







•21 



•98 



50 



•53 



•91 















100 



•62 



•89 



100 



•35 



•96 









150 



•71 



•84 















200 



•79 



•80 



200 



•44 



•95 









250 



•88 



•67 















3U0 



•96 



•50 



300 

 400 



•54 

 •63 



■93 

 •90 















500 



•73 



•84 



500 



•58 



•89 









600 



•82 



•76 



600 



■m 



•88 









700 



•92 



•57 



700 



800 



900 



1000 



•73 



•81 

 •88 

 •96 



•83 

 •76 

 •62 

 •41 



Critical temp. = 320° C. | Critical temp. =785° C. j Critical temp. = 1060° C. 



5. The curves which have been traced in fig. 1 indicate 

 that the behaviour of residual magnetism is of the same type 

 for each of the three ferromagnetic elements. This similarity 

 of type can be tested by plotting the fractional intensities on 

 a reduced scale of temperature, in which the critical tempe- 

 rature is treated as unity and other temperatures as fractions 



