128 



ROYAL SOCIETY OF CANADA 

 TABLE XIII 



Upper plate copper, 



It will be observed, also, that when the plates were 10 nun. apart, 

 there was a marked positive increase in the values. This was more 

 carefully investigated by taking a series of measurements with different 

 distances between the plates. The results obtained are given in Tables 

 XII and XIII, and are illustrated by the curves in Figs. 10 and 11. 

 It will be seen that, as the distance between the plates was increased, 

 the values of the charge acquired became more and more positive, until 

 a maximum point was reached, after which the values became more 

 negative. 



In these latter experiments it must be remembered that not only 

 was the distance between the plates varied, but, since the radium was 

 kept in a fixed position, the distance from the upper plate to the radium, 

 as a consequence, was varied also. Tbat this is an important factor 

 is shewn by the results of some measurements made with the radium at 

 various distances from the plates, which were kept at fixed distances 

 apart. 



The results obtained are given in Tables XIV, XV and XVT, and 

 are reprosent^ed graphically by the curves in Figs. 12, 13, and 14. From 

 these it will be obsen^ed that as the distance of the radium was increased 



