2Ü4 K. iioNi:>A : on the mutual inFj.uence 



It is to be noticed that though the transverse magnetizing 

 coil was wound round the wall of the tube very carefully along its 

 generating lines, small longitudinal magnetization was still to be 

 traced due to a current through the coil, when no magnetizing 

 field in that direction was acting, so that this was corrected for 

 each experiment. It is probably due to the magnetic œolotropy 

 of the tube. 



Although the longitudinal magnetizing held was kept con- 

 stant, the effective part of the field must vary, because the 

 change of longitudinal magnetization is necessarily accompanied 

 by that of the demagnetizing force. The influence of the change 

 on the intensity of longitudinal magnetization is considerable 

 in weak fields, but not so prominent in strong fields. In 

 weak fields, the efiective part decreases by the application 

 of transverse field, so that the increase of magnetization in 

 weak fields is considerably reduced. In stronger fields, it is 

 somewhat increased. Since the demagnetizing factor is very 

 small for the iron wire and the smaller tube, the effect is not 

 so remarkable as in the case of the larger tube. The small in- 

 crease of magnetization, in weak fields, foi' the latter is mainly 

 due to this cause. H in the tables I, II, IV denotes the initial 

 effective field. 



The same change was also measured by the ballistic method 

 to assure the absence of the effect of heating when it was ex- 

 amined by the magnetometric method. Starting every time from 

 a magnetically neutral state, I measured the change of magnetiza- 

 tion by the ballistic galvanometer, and obtained tlie presupposed 

 result. An example is given in the following table for the sake 

 of comparison. 



