D.  C.  COMMUTATING  MACHINES 


193 


At  distance 
from  pole 
face 

B 

p 

Cast  steel 

Cast  iron 

0 

718 

10.3                  2.06 

la 

2 

373 

2.78 

0.56 

la 

184 

0.677 

0.135 

~2~ 

119 

0.283 

0.057 

2  la 

91 

0.166 

0.033 

5  la 
2 

69 

0.095 

0.019 

3  la 

57 

0.065 

0.013