WINDS. 



nil 5 



regions — not through one great current, but innumerable ones, in all 

 directions, serving to intermingle the whole as it approaches the 

 Equatorial heats. The Variables flow toward the continents in 

 summer, when they are heated by the sun, and from them towards 

 the sea in the winter. The Polar winds are in like manner circulated 

 during half the year ; in the long period of night, they lie quiet in 

 consequence of the equable temperature which prevails. Nor must 

 we fail to give our attention to the areas of calm. They prevent the 

 access between the Trade Winds and Variables except by the Monsoons. 

 They constitute the barriers, or walls which confine these currents of 

 air to their proper limits, and prevent them flowing directly to the 

 heated area : on examination, we shall readily see that, if they were 

 permitted to do so, the circulation would soon cease, and everything 

 become stagnant. How beautiful and how simple is the arrangement 

 by which these barriers are maintained through an equable tempera- 

 ture, and the circulation kept within its proper limits ! 



The Monsoons form the great links of the circulation between the 

 Trade Winds and Variables; and as each hemisphere in its turn 

 becomes heated, the Variables alternate with each other, and with the 

 atmosphere of the regions of the Polar Circles. All move in perfect 

 harmony, exhibiting the wisdom and wonderful simplicity by which 

 the whole is governed. 



As the origin and cause of all winds is to be found at the area to 

 which they blow, it follows that the indications in that quarter are to 

 be regarded. The appearances to leeward, therefore, determine what 

 the weather is to be, — the reverse of the practice of sailors, and all 

 who claim to be weatherwise. 



VAPOli S. 



Although I have contended that the rotary motion of the earth 

 had no influence upon the surface currents of air in producing the 

 direction of the Trade Winds,. I am not disposed to deny that the 

 rotary motion has no effect upon the Vapor surrounding the globe. 



Vapor, like other matter, obeys and is subject to the same laws of 

 gravity, decreasing with the distance from the surface. 



If we suppose the earth a sphere, surrounded by water of the same 

 temperature, it would be enveloped in vapor, in equilibrium and at 



