193 



of somewhat narrowing the effective pole- 

 face presented to the armature. A trial 

 machine was built, on the type in use by 

 the Thomson-Houston Electric Company, 

 which consisted of a field structure with 

 inward radial cores and a cylindrical 

 armature with very flat coils laid on and 

 bound down, their curved ends out of 

 the field; not, however, being- turned 

 down toward the shaft, as is the case 



Fig. 39 



with the Westinghouse machine. The 

 field-poles had a width approximately 

 equal to one half the pitch, the armature 

 being smooth. In the trial machine the 

 coils were laid on so as to practically cover 

 the whole exterior of the armature- core, or 

 they were wound with but a narrow line 

 of open space in the center of each coil, 



