280 Proceedings of the Royal Society of Edinburgh. [Sess. 
temperature employed exceeding the previous one by about 30°. The 
ordinates in the diagram are the intensities of magnetisation, while the 
abscissae are the temperatures of baking. The continuous lines are ob- 
tained by testing the baked specimen at room temperature in fields of 8, 
16, and 110 C.G.S. units respectively. The dotted lines give the results of 
Fig. 4. 
similar tests made with the baked alloy cooled to — 190° C. The curves 
show the improvement of the material for high fields with baking at 
temperatures in the neighbourhood of 170° C. They also exhibit a 
marked deterioration in the magnetic quality after baking of the specimen 
about 250° C., and a subsequent recovery prior to the rapid deterioration 
after 330° C. This dip in the curves is very remarkable, and points to some 
extensive change in constitution of the material. It is noteworthy, too, 
