Lightning | 125 
ning bolt is observed. The bolt seems to shoot up in the man- 
ner of a rocket and so it is known as “rocket” lightning. 
GREAT BALLS OF FIRE! 
Ball lightning is one of the strangest of natural phenom- 
ena. Some experts question its existence or claim that it is 
illusory, but so many well documented observations are on 
record that its existence may be considered to be well estab- 
lished. It is usually described as a brilliantly luminous globe 
anywhere from the size of a lemon to that of a basketball. The 
literature abounds in accounts of balls of this kind of light- 
ning floating down chimneys and into windows, chasing 
frightened women, and exploding with considerable violence 
and even causing loss of life. An aeronautical engineer of the 
author's acquaintance describes one he saw in Freeport, Long 
Island, during a short summer thundershower. He says it 
floated gently down the street about three feet from the 
ground until it collided with a fire hydrant and with a loud 
clap disappeared. Another friend, a naval officer, tells of one 
which he saw as a child, a brilliant golden sphere which 
floated in his nursery window, frightened the nurse, and 
then entered the bathroom where it exploded, causing some 
damage to the plumbing there. Such balls have been ob- 
served plummeting from the clouds, bouncing upon the 
ground like rubber balls, and then rebounding up into the 
clouds again. Sometimes they simply grow dim and disappear 
quietly. Scientists have not yet discovered an explanation of 
the mechanism of this phenomenon. 
SHEETS OF FLAME 
Sheet lightning appears as broad diffuse patches of sud- 
den light behind large cloud masses. It is supposed to be 
