14000 



12000 



iOOOO 



8000 



6000 



4000 



'000 



■Condition of an Alloy of nearly Pure Iron and Aluminium. 299 



corresponding heating curve observed to be the same in 



these experiments *. 

 •Curve Y. (14th heating). — The first maximum is disappearing. 

 Curve VI. (13th cooling). — The heating andcooling curves 



are approaching one another in the neighbourhood of 



300° O. 

 The specimen was sent to Sheffield to be annealed. The 

 annealing consisted in heating the specimen in lime for 70 

 hours at about 950° C. and then allowing it to cool during 

 18 hours. 

 Curve VII. (5th heating after annealing) . — The heating and 



cooling curves nearly coincide at 300° C. The first 



maximum has disappeared ; the new maximum,, between 



500° C. and 600° C, is well marked in this curve. 

 Curve VIII. (4th cooling after annealing). — The heating and 



cooling curves are somewhat similar in general shape. 



This was not the case in the earlier experiments. 

 Experiments were also made with higher fields. As might 

 be expected the curves connecting the induction and tem- 

 perature for these fields were much smoother than those from 

 the experiments with the weaker field. Three curves are 

 shown : — Fig. 2. 



B 



* It was found that the cooling and following heating curve practically 

 coincided for the annealed impure specimens first investigated. 



X 2 



