56 
MR. S. W. ,J. SMITH ON THE THERMGMAGNETIC ANALYSIS OF 
Fig. 13. Meteoric iron (2nd winding). 
Variation of /a with <9 below 500 : C.— 
(i) when cooling from 850 ; C. is interrupted at 500" C. 
(ii) when reheating to 850° C. is interrupted at 625° C. 
permeability at ordinary temperature (cf 1st winding). From the data 88 to 100 it 
is seen that the greater part of the increase takes place during the time that the 
material is cooling from below 100° C. to the temperature of the air (cf. 99 to 100). 
The experiments 101 to 110 (fig. 12) seem to show that uninterrupted cooling from 
Fig. 14. Meteoric iron (2nd winding). 
Curves showing the variation, at temperatures below 500° C., of the permeability obtained after 
cooling from about 600° C. 
