516 



Mr. A. W. Ashton on the 



Table VII. — Readings of Current during Charge and 

 Discharge of a Paraffin- Paper Condenser, June 26, 1900. 



Charging wi 



th 190 volts. 



Discbarge after 20 minutes' Charge. 



Time in 



Current in 



Time in 



Current in 



seconds. 



Amps. XlO -8 . 



seconds. 



Amps. XlO" 8 . 



40-5 



1-938 



33 



1-726 



60 



1-514 



43 



1-403 



79 



1-303 



52 



1-197 



165 



•868 



59 



1-089 



270 



•720 



75 



•878 







87 



•773 



Equation : — 









c-3-8xl0- 8 = 2 



5-85 xlO- 8 --' 89 . 



Equation : — 









c=337xi 



q— 8^— -846 



Table VIII. — Readings of Current during Charge and 

 Discharge of Paraffin-Paper Condenser, June 26, 1900, 



Charging wi 



th 190 volts. 



Discharge after 20 minutes' Charge. 



Time in 



Current in 



Time in 



Current in 



seconds. 



Amps. Xl0~ 8 . 



seconds. 



Amps. XlO -8 . 



45 



278 



38 



246 



58 



2-46 



48 



2-04 



220 



1-396 



55 



1-83 



300 



1-26 



63-5 



1-62 



960 



•918 



75 



1-41 







82 



1-304 



Equation : — 





90 



1-197 



c-6-0xl0~ 8 =24 



■0xiT ,630 Xl0- 8 . 



114 



•982 







Equation: — 







c=54-7xl0- 8 r-' 849 . 



that the curves of resistance at different charging pressures 

 can be relied on. In the case of the okonite cable, however, 

 it is evident from the experiments made that the current is 

 still decreasing after several hours' electrification. Therefore 

 the final values of the resistance at each voltage, obtained by 

 increasing the pressure in steps, cannot be taken as a measure 

 of the true conductivity of the dielectric. That the charging 

 current is not quite proportional to the voltage may be seen 

 from the curves in iig. 2. If we take the mean of the two 

 curves obtained with a charging pressure of 51 volts as giving 



