WINDS, Sec. 95 



light on the correspondent actions of the polar and 

 tropical regions of the atmosphere, as well as on the 

 conflict and equilibrium of the north-west and soutli- 

 west currents, which are the principal winds of the 

 United States, 



Of the South-went Wind, 



The south-west wind, one of the three most pre- 

 valent in the United States, is more frequent there 

 during summer than winter, and more constant in 

 the western country than on the Atlantic coast. In 

 winter it seems as if it were unable to pass the bar- 

 rier of the Alleghanies. Sometimes, however, it 

 shows itself on the Atlantic coast with more impe- 

 tuosity, and particularly with greater coldness, than 

 are consistent with its habit and origin. But the 

 reason of this is easily perceived, when it is consi- 

 dered, that it has crossed the lofty region of the Al- 

 leghanies, frequently covered with snow during 

 winter, and in the west has found the earth drenched 

 with rain, the evaporation of which could not fail to 

 cool it. 



In the spring, become more frequent, it brings 

 temporary snows, deluges of rain, and even hail : 

 these however seem rather to belong to the north- 

 -east and north-west winds, the clouds of which 

 heaped up on the Alleghanies, it turns back, and 

 drives before it. This chain indeed forms the lists, 

 in which these opposite currents of air visibly con- 

 tend for the mastery. Frequently the observer 

 stationed on tlie plain may see the clouds marching 



