3S0 



C. B. Thwing — Photographic Method, etc. 



Interesting figures might be obtained by inserting rings 

 between the poles similar in form to the rings of which the 

 armature is composed. These figures illustrate a large class of 





Fig. 10. Motor-Field — Horseshoe Type. 



very instructive maps which might be made of the various 

 types of magnetic fields now in use. A careful study of a 

 set of such figures should afford valuable suggestions to the 

 designer of field magnets and transformers. 



The motors used in Figures 9 and 10 are shown with the 

 bearings removed in figure 1. 



Fig. 11. Electro-Magnet. 



Figures 11 and 12 represent the field above the poles of the 

 small electro-magnet shown in figure 1. 



