282 Mr. N. Eumorfopoulos on the Determination 



as the calculated ratio of the distances at which equal tem- 

 peratures should be found, instead of *60 and *55, the mean 

 ratios actually found in the two sets of experiments already 

 mentioned. 



In order to test the trustworthiness of the method employed, 

 one of the above rods was heated in the middle under the 

 game conditions as before, and isothermal points found on 

 each side of the heated portion. The results were satisfactory, 

 as the following numbers show : — 



20 mm. 



19 mm. 



40 



40 



60 



61 



80 



81 



At this point the experiments were abandoned for a time. 

 They were subsequently resumed, when a Bunsen burner was 

 used as the source of heat, in order to have a greater range of 

 temperature. In the experiments mentioned before, and 

 also in these, no screens were employed, a sheltered part of 

 the laboratory being used. The following are some of the 

 results obtained : — 



German Silver Rods. 



rx = 3*0 mm., r 2 = 2'5 mm., V/— = '91. 



Making # 2 = 10'3 cm., # x = 11*95 cm. as a mean of five 

 determinations, or 



5 = -86. 



As a mean of a large number of experiments, making 

 #•2=: 10*0 cm., x x was found to be 11*68 cm., or 



- 2 = '86. 

 x 1 



The arrangements were then slightly changed, so as to 

 experiment on a hotter part of the rod, with the following 

 result as a mean of a series of experiments : — 



x % = 10*0 cm., 3?!= 11*86 cm. ; or 



- 2 = *84. 

 The ratio of specific electrical resistances for these rods was 



