482 Mr. A. B. Meservey on the Potentials required 



A' andB'. The dotted lines show the corresponding parallel 

 plate curves, calculated in accordance with Paschen's law 



Vai&i__ 







Fig. 2. 















! 















/A 





1 















*f 

























V— ' 





T 







9 J 



/ 











i 







/ 



/ / 



r / 









/ 













/ 







/ 



/ ■ 





1 ' 





%r 



f 1 

 I 



! 







/ 



/ 













1 

 1 





/ 



/ 









.., 



I / 



II / 





„y 



/ 











\ 





1 



w 





/ 















» 



j 



' 1 



;/ 











b .j 







\ « 

 V* 



* «Jt 



/ 

















\^£ 









,^ 



^ 



V" 1 * 













V 



^j 



^ 







J^" 











-««. — ' 





















€ 9 



v^S 













Vr, 



S3W1 



■ « 



hi 



f w 



>• 



L 



1. 



6 



from the experimental curves of Prof. Townsend *. Fig. 3 

 shows the curves obtained for three of the seven diameters 

 used in air ; fig. 4 those for three of the five diameters used in 



* ' The Theory of the Ionization of Gases by Collision/ p. 60. 



