774 
DR. OLIVER LODGE ON ABERRATION PROBLEMS. 
Second s])in. 
X-wire. 
Vertical wire. 
Re.st. 
38^ 
28 
Spinning (at 1260) 
32 
321 
Rest again. 
37 
26 
Spinning again. 
30 
321 
Rest. 
38 
25 
Spinning. 
.321 
32 
Rest. 
44 
27 
To move the vertical wire into coincidence with the X (or vice versa), needed 
54 divisions of either micrometer head. 
The result of this set may be thus tabulated 
Width of a yellow band. 
Shift of the middle band. I 
1 
Stationary. 
651 
44 to right. 
1260 revolutions. 
631 
64 return. 
Stationary. 
62 
64 to right. ' 
1260 revolutions. 
611 
74 return. j 
Stationary. 
62 
7 to right. j 
1260 revolutions. 
634 
5 return. 
Stationary. 
70 
Average 64 
Average 6 
Practically, therefore, the absolute shift of the middle band was just the same as in 
the previous experiment, though the width of the bands was now only about one-third 
what it then was. 
Now reversed the brushes and went on. 
