36 ART. 1. — K. HONDA AND T. TERADA. 



nickel in weak fields, where its initial decrease was considerably 

 reduced. 



For Swedish iron and tungsten steel, the results somewhat 

 resemble those of the present experiment deduced from the magnet- 

 ic elongation. But they are several times greater as compared 

 with the results of the direct experiment. In nickel, the course 

 of the curve is considerably different from that of the present 

 experiment ; its form is, however, very interesting, if we consider 



it in connection witli that of the curve —rr- to H. It is here to 



A 



be noticed that as regards magnetic quality, the specimen in the 

 present experiment was veiy different from that used in the former 

 experiment, so tliat the quantitative comparison of the two results 

 is of little vafue. 



S 3. EXPERimENTS ON THE CHANGE OF RIGIDITY 

 BY (VIAGNETIZATION. 



(«) IVIeasu renient of the change of rigidity by the 

 osculation method. 



One of our methods consisted in giving torsional oscillation 

 to the wires maguetized with different fields and calculating the 

 coefficient of rigidity for different fields from the periods of oscil- 

 lation. The Avires tested wx're the same as those used in the 

 above experiment for the change of elasticity. The wire was 

 hung vertically in the field of the magnetizing coils used in the 

 previous ex]ierimeiit. Its upj)er end was brazed to a rigid brass 

 rod, which was clam})cd to the i'rame above. To the lower end, 

 a similar rod was brazed, to which the oscillating weights were 

 fixed. In order to sullicientlv diminish the disturbance due to 



