436 THE PHYSICAL GEOGRAPHY OF THE SEA. 



Ditto of the counter- before Stated, toward their pole more steadily and 

 trades. briskly tliaii do the counter-trades of the northern 



hemisphere. To give an idea of the difference of the strength of 

 these two winds, I cite the fact that vessels sailing through the 

 latter, as from New York to England, average 150 miles a day. 

 Along the corresponding latitudes through the former, as on a 

 voyage to Australia, the average speed is upward of 200 miles a 

 day. Consequently, the counter- trades of the southern hemi- 

 sphere transport in given times larger volumes of air toward the 

 south than our counter-trades do toward the north. This air re- 

 turns to the tropical calm belts as an upper current. If, descend- 

 ing there, it feeds the trade-winds, then, the supply being more 

 abundant for the S.E. trades than for the N.E., the S.E. trades 

 must be the stronger ; and so they are ; observations prove them 

 so to be. Thus the crossing of the air at the irojpical calm belts, 

 though it may not be proved, yet it is shown to be so yqtj prob- 

 able that the onus of proof is shifted. It now rests with those 

 who dispute the crossing to prove their theory the true one. 



817. Arrived at this point, another view in the field of conjec- 

 The waves they get up. turc is prescutcd, 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 con- 

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

 there nearly so great on the average as it is in the extra-tropical 

 regions of the south. This fact is well known among mariners. 

 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 pre- 

 A-ail there. The waves driven before these winds assume in their 

 regularity of form, in the magnitude of their proportions, and in 

 the stateliness of their march, an aspect of majestic grandeur that 

 the billows of the sea never attain elsewhere. 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 in stately march, 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 con- 



