on the Magnetic Properties of Iron. 17 



It will be seen from the figure that the general form of the 

 curves resemble those given for iron, but the corresponding 



Ficr. 9. 



2200 



















2000 



1800 





































1600 

 1400 































m 









a. 1200 



1000 



























if, 













800 









**A 







\ 







600 





1 











\ 











y 





/" 



400 







/ 















200 























* 



















100° 200° 300° 400° 500° 600° 700° 

 Temperature in Degrees O. 



800° 



magnetic forces are much higher in the case of the tungsten 

 alloy. 



The curves given in the figure show more clearly than was 

 possible with iron the effect of heat in hastening the transition 

 from stage to stage of the magnetizing process. Under a 

 magnetic force of about 15 C.G.s. the third stage is just 

 entered upon at the ordinary temperature, and heating has 

 very little effect on the permeability until a temperature 

 of about 550° C. is passed, then the permeability falls. 



It will be seen that, unlike the case for iron, the rate of 

 increase in permeability as the second stage is brought on 

 is practically the same for all magnetizing forces. This 

 appears to indicate that the rate of transition from one to the 

 other is independent of the temperature, because under a 

 force of 8*156 C.G.S. the second stage is brought on at a 

 comparatively low temperature, and as the force is reduced 

 the temperature necessary to bring on this stage increases. 



The maximum permeability obtained in each case, and the 

 temperature at which it occurs, increases as the magnetic 

 force is reduced, until the permeability reaches a value of 

 about 2200 at a temperature of 650° C. with a force of about 

 2*04 c.G.S. On reducing the magnetizing force below this value, 

 the maximum permeability obtained in each case decreases. 



Phil. Mag. S. 5. Vol. 50. No. 302. July 1900. C 



