﻿846 



Messrs. E. W. B. Gill and F. B. Pidduck on 



These sparking potentials V are plotted as usual in fig. 4 

 against pa 1 , and to get more points on the curve the 

 following sparking potentials were also observed in the above 

 described way, but without obtaining the values o£ a and /3. 



V 

 t 



280 



£60 



£40 



220 



200 



I3C 



160 



140 



Table IX. 



pa'. 



V. 



1-87 



175 



498 



162 



16 



210 



22-4 



240 



35-2 



280 



Fig. 4. 







* 















A 



y 















A* 

















®\ 

















/> 

















u 

















fv 

















A* 

















/\° 







n / 











* v 







4 















A\ 

















r/<fc 













/ 













1 





/ 



























T 



/ 















G 















■ 



/>< 



5 10 15 20 25 30 35 



It will be seen that for values of p and a' such that 

 Da' = 4: } a discharge will pass if 156 volts are applied : and it 



