112 



ROYAL SOCIETY OF CANADA 



be seen from it that a close connection exists between the surface con- 

 dition and the nature of the charge acquired. 



Variations with time in the magnitude of the charge were also 

 observed in a number of cases, but these, in so far as the observations 

 extended, were not such as to indicate any 'periodicity. In only one 

 case, that of lead No. 1 in lead No. 2, were obson^ations made for 

 a very extended period of time, and the resulting curve (vide Fig 1), 

 although showing marked variations, would hardly indicate the presence 

 of definite periodic changes. 



TABLE I. 



No. 



Combination. 



Lead No. 1 in No. 2. 

 Lead No. 1 in No. 2. 



Lead No. 1 in No. 2. 



Lead No. 1 in No. 2. 



Lead No. 1 in No. 2. 



Lead No. 1 in No. 2. 

 Lead No. 1 in No. 2 . 



Lead No. 1 in No. 2. 



9 Lead No. 1 in No. 2. 



10 Lead No. 1 in No. 1. 



11 Lead No. 1 in No. 3 



12 Lead No. 1 in No. 3 



Sign of 

 charge of 

 insulated 

 cylinder. 



+ 



+ 



Maximum and 

 minimum val- 

 ues of potential 

 of insulated 

 cylinder in 

 millivolts. 



102 approx. 

 113 



79, 72, 78. 



46, 32 



45, 41, approx, 



31.8 



29 approx. 



27, 24, 25 



13 

 84.6,83, 31 



59, 58, 55 

 22, 9 



Remarks. 



Needle positive. 



Needle negative. Same 

 day as No. 1. 



Needle positive. Radium 

 used. Four days after 

 No. 1. 



After cleaning. Radium 

 used. Needle positive. 



Needle negative. Radium 

 used. 



One day after No. 4. 



Radium inside inner cyl- 

 inder. One day after 

 No. 6. 



Four days after No. 4. 

 Radium used. 



Twenty days after No. 4. 



Fourteen days after No. 

 4. No. 1 had not been 

 cleaned for some 

 months. 



Radium used but re- 

 moved between the 

 values 58 and 55. 



Radium used. Lead No. 1 

 had been cleaned about 

 7 days. 



