Model of Ferromagnetic Induction. 



501 



strongly than the other. When the clearances at the sides of 

 W, between it and the fixed coils, are small, its limit of stable 

 deflexion is very narrow. The model is of course to be 

 understood as having a second pair of similar controlling- 

 coils set in a transverse plane, and it is easy (in imagination) 

 to extend the construction to three dimensions, adding other 



Fi-r. 4 



Fij 



single electron orbit 

 interesting- 



pairs of elliptical coils and supposing W free to turn about 



any axis in its own plane. Here a 



suffices to constitute the Weber element. It 1 



to find that all the main characteristics of ferro-magnetism 



are capable of representation by means of models which 



embody the same ideas in two widely different forms, based 



respectively on the two conceptions of atomic structure which 



physicists and chemists are endeavouring to reconcile. 



