142 THE ROYAL SOCIETY OF CANADA 
With pressure (c) 
Revolutions per sec. Resistance. 
-124 176 ohms. 
-115 96-22 
-112 80 Gi 
-108 75 < 
-1057 64 
-102 53:50 ES 
-100 48 “ 
-097 | 43 sé 
-094 40 « 
-0926 39 g 
-087 33 “9 
See Curve IV Fig. 2. 
With pressure (d) 
Revolutions per sec. Resistance. 
-124 | 76 ohms. 
-115 O3 Sue 
-112 53 à 
_-108 AG-AULE 
-1057 39-578 
-102 33 s 
-100 Doe te 
-097 DA DOS 
-094 20 “ 
-0926 LOUE 
-087 142 
See Curve V Fig. 2. 
It was observed that with a small pressure and the faster speeds 
the spot of light on the scale seldom came to rest but vibrated back 
and forth. The preceding tabulated results are the mean of a large 
number of such vibrations. For larger pressures the spot was steadier. 
The curves were repeated many times, and when the needle and disc 
were under the same conditions the curves were the same. 
