354 Dr. L. T. More on the Changes in Length 



vary by more than one per cent. The current was applied 

 suddenly, and as soon as a reading was taken the contact was 

 broken. This operation was then repeated, the current being 

 increased each time, and readings taken until the maximum 

 current was reached. By this means temperature-effects 

 which are relatively slow to act were avoided. 













Fig. 3. 



















&*/o r 

























3.0 f 































*SL 



















<>*' *S1 





It* 



mi 





-•^ 1M 





iXt.i 





H 



It 

























e 



r 























to 



goo 

































jS" 















60 



Goo 













^S* 











***., 



440 jT 















xo 



2oo 

























R^ 

























-* — ■ 













X 





ZOO 



i+OO 



bOO 



goo 



10 



/-*»V 



0. — Elongation and intensity of field. 

 B. — Elongation and magnetization. 

 A. — Do. corrected. 



Fig. 3, C shows the relation between the elongation per 



unit length, -y x 10 7 , and the intensity of tne field, H. This 



curve is seen to closely resemble in form those given by 



