714: Prof. Stroud and Mr. Oatos on the Application of 



should be. We have been driven to the conclusion that the 

 ratio of certain pairs of our capacities is a function of the 

 temperature. This may well be the case when we consider 

 that the capacities are finally adjusted by squeezing. The 

 result of a change in temperature may thus produce much 

 greater effects due to stress in the case of one capacity than 

 in that of another. This notion is confirmed by the following 

 very rough experiments on the effect of change of tem- 

 perature on the ratio of two capacities, the results of which 

 are given in Table II. The experiments would have been 

 done much more carefully if it had been possible to have 

 measured the temperature of the condensers, but no provision 

 had been made in the box for the insertion of a thermometer. 

 We propose to investigate this point later. 



Table II. 



Remarks. 



c,. 



C,. 



B. j 



Left current on for five minutes and 1 



tested ] 



Left and tested again 



0-5 



•05 B 



100374 



100400 i 



100360 



100370 ! 



101390 1 

 100420 i 

 100450 i 

 100450 

 100394 



Warmed the box up in front of a fire 1 



and tested again J 



Warmed again and tested 







" " 



Tested again next morning 











These results seem to show that the ratio of the two 

 capacities compared decreases as the temperature rises. If 

 it be true that the ratio of two capacities varies with tem- 

 parature, it follows that a capacity must have quite a 

 sensible temperature-coefficient. 



We also had in our possession a Kelvin air-leyden made 

 by White and engraved as '0025 M.F. This we compared 

 with the Elliott-box with the followdnof results. 







Table III. 





Cr 



C,. 



E.. 



E,. 



C,=C,.|-^M.F.'s. 



The 



The 



19705 



79703 



•0024722 



Kelvin 



Elliott 



206-90 



83689 



•0024723 



air- 



Box 



216-74 



87660 



•0024725 



leyden. 



totalling 



226-58 



91681 



■0024714 





1 M.F. 



236-42 



95654 



•0024716 







246-27 



99595 



•0024727 







256-11 



103624 



•0024715 







265-95 



107625 



-0024711 1 







275-80 



111636 



•0024706 ! 



1 



