I9II-] OF ELECTRICITY THROUGH FLAMES. 403 



same sense a region of conduction. Here tributary discharge chan- 

 nels will form. These discharge channels branch out from the main 

 channel and elongate in a direction opposite to that in which the 

 corpuscular stream is flowing. This end of the discharge is called 

 forked lightning. Probably in most cases the ends of the discharge 

 are hidden by clouds. 



Fig. I is a reproduction of the original plate. Figs, 2, 3 and 4 

 are reproductions of photographic reversals of the originals. 



