18 ART. 4.— K. nOXDA A>"D T. TERADA. 



For small tensions, tlie change is an elongation in low fields, 

 attains a maximum in a certain field, passes zero, and afterward 

 is changed to a contraction. The maximum elongation decreases 

 with the increasing tension, driving the zero toward the weak 

 field ; and beyond a certain tension, the length of the wire steadily 

 contracts with the increase of the field. It seems also that the 

 field corresponding to the maximum elongation slowly moves to- 

 ward the v/eaker fields as the tension is increased. These results 

 are in complete agreement with those obtained by former ex- 

 perimenters. 



The change of elasticity for this sample was unexpectedly 

 small, its amount being not very much greater than the limit 

 of experimental error. The values obtained are given in Table 

 VIII and in Fig. 6 with a full line. 



TABLE VIII. 



Thus, -y- is as a wliole very small, and increases with the 

 field tending to an asymptotic value. 



On the other hand, the calculated values of -y- from the 

 magnetic elongation are decidedly greater than those obtained by 

 our direct method, as may be seen from Table IX, and Fig 6 in 

 dotted lines. The difference is remarkable as well as interesting. 



