[HENRY] CONTACT RESISTANCE BETWEEN CONDUCTORS 139 
Revolutions per sec. Resistance. 
-124 990 ohms 
-115 Sor veri 
-112 10) ee 
-108 TV de 
-1057 [PISE 
-102 O0 LE 
-100 
-097 SAIS 
-094 543 
-0926 SOL Pat 
-087 510 “ 
See Curve I Fig. 2. 
The next observations taken were to see if it were possible to 
exert such a pressure as to always have good contact even if the disc 
was revolving at its greatest speed. The spring was wound and the 
disc adjusted as before. It was found that when the current sent 
through the relay was 73-3 times as great as in the previous case, 
it caused such a pressure that there were only very slight deviations 
from good contact for the maximum speed of the motor clock. 
Revolutions per sec. Resistance. 
-124 2-3 ohms. 
-115 Dis Oh aes 
-112 2-0 
-108 1-8 
-1057 1-8 
-102 1-8 
-100 RESTES 
-097 1-8 
-094 1-6 
-0926 1-6 
-087 1-0 
L Fi 
See Curve VI Fig. 2. 
