36 



Hail Storms. 



dimensions. It no doubt has appeared to many a strange circum- 

 stance, that when falling of such large size, they have not been more . 

 fatal to animals. For if a pebble, or any other solid body of equal 

 bulk, was to fall from the same height, we must suppose that its 

 velocity, from its specific gravity, would be such as to render its 

 effects terrible and destructive. We can only imagine the large hail- 

 stones that often fall, to have in some way, their specific gravity so 

 much lessened as to render the largest of them, comparatively light and 

 inoffensive in their fall. This is done, by their expansion in the act 

 of freezing, by which means a hollow cavity is produced, filled with 

 air. This air cell, with others attached as they enlarge, greatly les- 

 sens their specific gravity. It acts like the air-bladder of a fish, 

 which enables him to rise to the surface in deep water, or the air 

 cells in the bones of birds which lessen their specific gravity, so 

 much as to assist their flying. 



I first observed this peculiar structure of hail-stones, during a 

 short residence in Athens, Ga. in the spring and summer of 1831. 

 In May of this year a cloud come over from S S E. It presented 

 the peculiar sea green appearance of hail clouds, and portions of it 

 seemed to move in irregular directions, as if acted on by contrary 

 currents of wind. It also was accompanied by a considerable wind 

 and vivid flashes of lightning. After the rain had commenced falling, 

 the wind was to a degree lulled, and large pieces of hail commenced 

 falling, and continued to fall till the ground was covered. After the 

 storm had passed, I walked into the yard and examined many of the 

 stones of the largest size. T was surprised to find in the center of 

 each a circular air cell. The annexed figures in the plate represent 

 their most common appearance. The largest were a half, or three 



