30 



ART. 4. — K. HONDA AND T. TERADA. 



From the above results for nickel steels, we may conclude 

 that for small tensions, the change of elasticity is considerably 

 less than that calculated from the tension effect on the magnetic 

 change of length. But the difference between the two becomes 

 less and less as the tension is increased, almost vanishing for 

 great tensions. 



(6) lYIeasurement of the Coefficient of Elasticity. 



A 



?./( 





[Hki 



oo^ 



t 



w 



t 



s^ 



Since it was necessary, in the calculation of —p^i to know 



the coefficient of elasticity in no field, a special arrangement was 



devised for this purpose. 



Referring to 



the figure, m is the 

 specimen, at the 

 ends of which brass 

 rods of moderate 

 diameter are braz- 

 ed. The upper rod 

 is clamped to the 

 tripod Ä resting on 

 a rigid wooden 

 frame. To the 

 lower rod, is at- 

 tached a flexible 

 cord, which passing 

 through the inter- 

 space between the 

 grooves of two fric- 

 tion wheels P fixed 



