WINDS. 



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would prevail. But it is known that we have strong breezes from the 

 west within the Tropics and between the Trades, and in the Indian 

 and Pacific Oceans from the west and northwest, where they continue 

 for months together. 



The hypothesis I have quoted assigns the rotary motion, combined 

 with the aerial currents from the Poles, to give direction and to be the 

 cause of the Trade Winds ; in other words, forming the mighty engine 

 which it is supposed acts to keep up the circulation of the whole 

 atmosphere. Can it be possible that the same particles of air are 

 carried from such great distances only to supply these great aerial 

 currents, when we perceive that these particles must be subjected to 

 the surface winds, calms, and heated areas, undergoing all the changes 

 air is liable to, from moisture, as well as heat, in its passage ? 



Now, the direction of all winds is towards the heated areas of the 

 ocean, and the same tendency likewise prevails towards these areas on 

 the land, unless a high range of mountains should intercept their flow. 

 And according as the difference of temperature existing in the near or 

 remote regions is greater or less, will the currents of air or winds tend 

 towards them with greater or less velocity. When the air thus induced 

 becomes heated, it rises with the vapor to the upper and colder 

 regions, the moisture is condensed, and the formation of clouds is the 

 result, which are borne off in the direction of the currents of air. 



The air of the upper regions, we conceive, seeks in like manner the 

 nearest rarefied spaces which may exist, and passes off either to the 

 north, south, east, or west, or changes its relative position in altitude, 

 according to its specific gravity or temperature. 



The ocean occupies three-fourths of the surface of the earth. It 

 must necessarily have a greater and more extended influence than the 

 land, and its mean temperature is 6° above that of the land. 



If the great current from the Poles to the Equator, as assigned by 

 the old theory, existed, we should find the whole course of the winds 

 different from what they are known to be. In order to make this 

 more clear, I will give the direction of the currents through the regions 

 of the Trade Winds in the North and South Atlantic. On the confines 

 of the Trade Winds, or between the latitudes of 28° and 30°, calms 

 are very prevalent, both north and south, extending along their 

 limits. Proceeding south, the wind, instead of coming from the north, 

 is from the east. Advancing southward, it shifts to the east-northeast, 

 then northeast, north-northeast, and finally it becomes north, or at 

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