DRS. J. AND E. HOPKINSQN ON DYNAMO-ELECTRIC MACHINERY. 341 
III. The same frame was raised a height of, 6'35 eras, above the armature in a 
vertical plane. The deflections were : 
21 left. 
Zero 
Deflection 
Zero . 
Deflection 
98 , } magnets made. 
35 left. 
8 right; magnets short-circuited. 
Hence, deflection to left ==50 
„ right = 43 
and mean deflection = 46'5 
or, reducing to one convolution = 4‘6. 
IV. The same frame was again lowered on the armature and pushed inwards so as 
to lie symmetrically within the space between the limbs. The deflections were : 
Zero 
Deflection 
32 right. 
112 ,, magnets made. 
48 left; magnets short-circuited. 
giving a mean of 80 ; or, reducing to one convolution, = 8'0. 
Let G represent the leakage through a vertical area bounded by the armature, and 
a line 7'6 cms. above the armature, and of the same width as the pole-pieces; let Tl 
be the remainder of the leakage between the limbs; then II. and III. give 
§ G + 3 R = 5 ' 5 
2 
whence 
G=1'35 
R=6-9 
Again IV. gives 
^(G+R)=8'0 
therefore 
G + R=9-6 
which shows an agreement as near as might be expected considering the rough nature 
of the experiment, and that the leakage is assumed uniform over the areas considered. 
We take 
G=D6 
11 = 8-0 
