3-6 

 3-4 

 3-2 

 3-0 

 2-8 

 2-6 

 2-4 

 2-2 

 2-0 

 1-8 

 1-6 

 1-4 

 1-2 

 1-0 



IN TORSIONAL OSCILLATION 119 



FIGURE 2 Showing relation of (n) and (a) with Temperature. 



140 

 130 

 120 

 110 

 100 



80 

 70 



40 

 30 



10 



X 



49 



270 



290 310 



330 



350 



370 



380 



410 



430 



450 



470 



490 



TIME EFFECT 



In these temperature experiments, the plan adopted was 

 to raise the brass wire up to the temperature indicated, and 

 to remove it from the furnace at once, as it was found by 

 previous tests that the change was a sudden one. Wires 

 were introduced for J hour, J hour, 5 minutes, and 1 minute, 

 respectively, at a temperature of 400 C., and in each case 

 the same values of n got. 



LOWERING OF TEMPERATURE 



A length of original 1 wire was allowed to remain in liquid 

 air for over half an hour and subsequently tested, but this 

 seemed to have no effect upon the value of n ; and this result 



1 This term will be used in subsequent pages to denote a length of wire cut from 

 a coil as supplied by the dealer. 



