LIGHTNING. 5 



Q. Why is lightning sometimes FORKED ? 



A. When the lightning-cloud is a 

 long way off, the resistance of the air is 

 so great, that the electrical current is 

 diverted into a zig-zag course. 



Q. Why does the resistance of the air make 

 the lightning zig-zag ? 



A. As the lightning condenses the 

 air, in the immediate advance of its path ; 

 it keeps flying from side to side, in order 

 to pass where there is the least resistance. 



Q. How does lightning CONDENSE the air in 

 the immediate advance of its path ? 



A. The air is condensed by the 

 rapidity of the lightning-flash. 



Q. Why is FORKED LIGHTNING more DANGE- 

 ROUS than a straight flash P 



A. Whatever resists the flash, diverts 

 its course ; and when terrestrial objects 

 offer resistance to the current, they are 

 in great danger of being destroyed. 



Q. Why are there sometimes TWO flashes of 

 forked lightning at the same moment ? 



A. Sometimes (in very severe storms) 

 a flash of lightning will divide into two 

 or more parts; and then each branch 

 assumes the zig-zag form. B 3 



