﻿6 MORRIS-AlREY & SPENCER, Resistivity of Carbon. 



accompanied by a corresponding one on the other, the 

 two occurring at exactly the same time, thus shewing that 

 both coils are affected at the same time by temperature 

 changes, so that we can assume them to be at the same 

 temperature at any instant during the experiment. 



Fig 3- 



The table on page 8 shews the values of the specific 

 resistance of carbon (p) at various temperatures expressed 

 in platinum degrees//. 



The curve in Fig. 4 shews the result graphically. The 

 curve is practically a straight line until a temperature of 

 — 150 is reached, when there is a decided deviation, the 

 curve returning, however, to a point on the straight line 

 again at the temperature of liquid air ( — i82°C). 



In the experiments of Dewar and Fleming the 

 resistance of carbon was determined only at three points 

 below zero, one of which was the boiling point of liquid 

 air and the other two being points on the straight portion 

 of the curve. The deviation from the straight line curve 



