INDICATIONS OF RAINY WEATHER. 155 



expected or continued; but when they fly 

 low, and close to the ground, rain is almost 

 surely approaching. Can you account for 

 this ? 



Hal. — Swallows follow the flies and gnats, 

 and flies and gnats usually delight in warm 

 strata of air ; and as warm air is lighter, and 

 usually moister, than cold air, when the 

 warm strata of air are high, there is less 

 chance of moisture being thrown down from 

 them by the mixture with cold air; but 

 when the warm and moist air is close to the 

 surface, it is almost certain that, as the cold 

 air flows down into it, a deposition of water 

 will take place. 



Poiet. — I have often seen sea gulls as- 

 semble on the land, and have almost always 

 observed that very stormy and rainy weather 

 was approaching. I conclude that these 

 animals, sensible of a current of air approach- 

 ing from the ocean, retire to the land to 

 shelter themselves from the storm. 



Orn. — No such thing. The storm is 

 their element; and the little petreL enjoys 

 the heaviest gale, because, living on the 



