290 



C. G. KNOTT. 



u charcoal furnace. The observations of resistance were made as the 

 system was coohng, the Cfjljalt and platinum being thrown alternately 

 into the Wheatstone Bridge. The instants at which the Ijalancing was 

 effected were carefully noted, so that it was an easy matter to inter]:>olate 

 between two successive measurements for the (3ne wire that resistance 

 which correspc^nded to the intermediate measurement for the other. 



By this means more than twenty distinct pairs of measurements 

 were obtained, every C(jbalt resistance having its corresponding plati- 

 num resistance. After all corrections were made the platinum resis- 

 tances were di\'ided l^y the resistance of tlie |)latinum at 7°C. ; and 

 similarly all the cobalt resistances were di\ideil by the resistance of 

 the cobalt at this same tempérât lu'e. The numbers were then classified 

 into groups so as to afford the means of calculating by interp(3lation 

 the cobalt resistances which corresponded to assumed convenient values 

 of the platinum resistances. These are the numbers given in Table 

 II. which epitomises the results of four distinct experiments. The 

 measurements were all made during cooling, and the higher values are 

 accordingly tabulated first. The first column contains the platinum 

 resistances, taken as convenient multiples of the resistance at 7° C. 

 measured afler the experiment ; and the ()ther columns gi\'e in order 

 the corresponding resistances of the cobalt. 



Table II. 



