BETWEEN LONGITUDINAL AND CIRCULAR MAGNETIZATIONS. 305 



périment of E. Rhoads^^ on the effect of fibrous structure intro- 

 duced by rolling thin iron plate, with regard to the intensity of 

 magnetization and the change of length by magnetization. From 

 Fig. 13, we see that the curve of circular magnetization re- 

 sembles that of steel ; hence it is to be expected, that the change 

 of circular magnetization by longitudinal field is comparatively 

 small. In general, the change of magnetization is less witli 

 liarder (magnetically) iron or nickel. 



It was also observed in the iron and nickel tubes that the 

 intensity of circular magnetization when we first magnetize it 

 circularly and then longitudinally is always greater than when 

 the order of magnetizations is reversed. 



III. Theory. 



From the molecular theory of Weber, W. Siemens"^ conclud- 

 ed that the magnetization in a given direction should be different, 

 according as the field perpendicular to that direction exists or 

 not, and that in strong fields near saturation the magnetization 

 must diminish. 



G. Wiedemann'^^ also deduced the same conclusion from the 

 hypothesis of molecular magnets, and added that in weak fields 

 magnetization increases. 



Using the equations established by Poisson and Kirchhoff, W. 

 H. Schnitze''^ concluded that the magnetization in a given direction 

 must increase by applying a magnetizing force perpendicular to it, 



1) Phy. Rev. 7, 1898, 65. 



2) loc. cit. 



3) Wiedemann's Electricität, 3, 725. 



4) loc. cit. 



