ROYDS. 



Phil. Mag. Ser. 6, Vol. 19, PL IV. 



Fig. 1.— Sn. 

 city ='0306 mfd. 

 Period =3-0 X 10" 5 sec. 

 A = initial air-discharge. 

 B=a second air-discbarge of 



short duration. 

 C = air-discharge of long 



duration. 

 Lower electrode initially 



positive. 



Fig. 2. — Lower electrode Hg, 

 upper electrode Pb. 



Capacity =0306 mfd. Period =30 x 10 ~ 5 sec. 

 Upper electrode initially positive. 



Fig. 4. — (Positive photograph) Mg. 

 Capacity = -0206 mfd. Period=9*5xl0 -5 sec. Lower electrode initially positive. 



Fig. 3.— (Positive 

 photograph) Sn. 



Self-ind uction = "0337 

 henry. 



Fig. 5. — Ca. 



Capacity =0306 mfd. 



Period = 1 65 x 10 " 5 sec. 



Upper electrode initially positive. 



