43G PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



817. Tlie leaves the?/ (jet uj). — Arrived at this point, another view 

 in tlic fiekl of conjecture is presented, which it is proper we 

 should pause to consider. The movements of the atmosphere on 

 the polar side of 40° N. are, let it be repeated, by no means so 

 constant from the west, nor is the strength of the westerly winds 

 there nearly so great on the average as it is in the corresponding 

 regions of the south. This fact is well known among mari- 

 ners. Every one who has sailed in that southern girdle of 

 -waters which belt the earth on the polar side of 40'^, has been 

 struck with the force and trade-like regularity of the westerly 

 winds which prevail there. The waves driven before these winds 

 assume in their regularity of form, in the magnitude of their pro- 

 portions, and in the stateliness of their march, an aspect of 

 majestic grandeur that the billows of the sea never attain else- 

 where. No such waves are found in the trade-winds ; for, 

 though the S.E. trades are quite as constant, yet they have not 

 the force to pile the water in such heaps, nor to arrange the 

 waves so orderly, nor to drive them so rapidly as those " brave " 

 winds do. There the billows, chasing each other like skipping 

 hills, look, with their rounded crests and deep hollows, more like 

 mountains rolling over a plain than the waves which we are 

 accustomed to see. Many days of constant blowing over a wide 

 expanse of ocean are required to get up such waves. It is these 

 winds and waves which, on the voyage to and from Australia, 

 have enabled the modern clipper-ship to attain a speed, and, day 

 after day, to accomplish runs which at first were considered, even 

 by the nautical world, as fabulous, and are yet regarded by all 

 Avith wonder and admiration. 



818. A meteorological corollary. — Seeing, therefore, that we can 

 bring in such a variety of facts and circumstances, all tending 

 to show that the S.E. trade-winds are stronger than the N.E., and 

 that the westerly winds which prevail on the polar side of 40° S. 

 are stronger and more constant than their antoecian fellows of 

 the north, we may consider it as a fact established, independently 

 of the conclusive proof afforded by Plate XIII., that the general 

 system of atmospherical circulation is more active in the southern 

 than it is in the northern hemisphere. And, seeing that it blows 

 with more strength and regularity from the west in the extra- 

 tropical regions of the southern than it does in the extra-ti epical 

 regions of the northern hemisphere, we should deduce, by way 

 of corollary, that the counter-trades of the south are not so easily 



