lUiS A'lMOSrHEllE. g3 



show that, if ever it be answered by man, he must consult the 

 science of astronomy. It has been recentlj^ all but proved, that 

 the earth and sun, with their splendid retinue of comets, 

 satellites, and planets, are all in motion around some point or 

 centre of attraction inconceivably remote, and that that point 

 is in the direction of the star Alcyon, one of the Pleiades 1 

 Who but the astronomer, then, could tell their " sweet influ- 

 ences ?" And as for the general system of atmospherical circu- 

 lation which I have been so long endeavouring to describe, 

 the Bible tells it all in a single sentence : " The wind goeth 

 towards the south, and turneth about unto the north ; it whirleth 

 about continually, and the wind returneth again according to his 

 circuits." — Eccl. i. 6. 



217. Sloughing off from the counter trades. — Of course, as the 

 surface winds, H J K, and T U V, approach the poles, there must 

 be a sloughing off, — if I may be allowed the expression, — of air 

 from them, in consequence of their approaching the poles. For 

 as they near the poles, the parallels become smaller and smaller, 

 and the surface current must either extend much higher up, and 

 blow with greater rapidity, or else a part of it must be sloughed 

 off above, and so turn back before reaching the calms about the 

 poles. The latter is probably the case. Such was the conjec- 

 ture. Subsequent investigations* have established its correct- 

 ness, and in this way : they show that the south-east trade- 

 winds, as in the Atlantic, blow, on the average, during the year, 

 124 days between the parallels of 25° and 30^ S., and that as you 

 approach the equator their average annual duration increases 

 until you reach 6^ S. Here between 5^ and 10"^ S. they blow on 

 the average for 329 out of the 365 da3's. 



218. Tlie air which sujpjplies tlie soutli-east trade-idnd in tlie hand 

 h^ does not cross the band 25°. — Now the question may be asked, 

 ^Yhere do the supplies which furnish air for these winds for 329 

 days come from ? The " trades " could not convey this fresh 

 supply of air across the parallel of 25° S. during the time 

 annually allotted for them to blow in that latitude. They cannot 

 for these reasons : (1.) Because the trade- winds in lat. 5° are 

 stronger than they are in lat. 25°, and therefore, in equal times, 

 they waft larger volumes of air across 5° than they do across 

 25°. (2.) Because the girdle of the earth near the equator is 



* Nautical Monographs, No. 1, Observatory, "Washiugton, October, 1859. 



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