448 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOKOLOGY. 



effects of the conden«ation of vapour borne by tlioso siircliarged 

 winds, and to the immense precipitation in the anstral regions, 

 shall we ascribe this diminution of the atmospherical pressure in 

 high south latitudes? It is not so in high north latitudes, 

 except about the Aleutian Islands of the Pacific, where the sea 

 to windward is also wide, and where precipitation is frequent, 

 but not so heavy. The steady flow of " brave " Avinds towards 

 the south would seem to call for a combination of pliysical con- 

 ditions about their stopping-place in the antarctic regions, 

 exceedingl}" favourable to rapid, and heavy, and constant pre- 

 cipitation there. The rain-fall at Cherraponjie and on the slopes 

 of the Patagonian Andes reminds us what those conditions are. 

 There mountain masses seem to perform in the chambers of the 

 upper air the office which the jet of cold water does for the 

 exhausted steam in the condenser of the engine. The presence 

 of land, not water, about this south polar stopping-place is there- 

 fore suggested ; for the sea is not so favourable as the mountains 

 are for aqueous condensation. 



835. The topographical features of the antarctic hands. — By the 

 terms in which our proposition has been stated, and by the 

 manner in which the demonstration has been conducted, the 

 presence in the antarctic regions of land in large masses is called 

 for ; and if we imagine this land to be relieved by high moun- 

 tains and lofty peaks, we shall have in the antarctic continent a 

 most active and powerful condenser. If, again, we tax imagina- 

 tion a little farther, we may, without transcending the limits of 

 legitimate speculation, invest that unexplored land with 

 numerous and active volcanoes. If Ave suppose this also to be 

 the case, then Ave certainly shall be at no loss for sources of 

 dynamical force sufficient to give that freshness and vigour to 

 the atmospherical circulations A\diich observations have abun- 

 dantly shoAvn to be peculiar to the southern hemisphere. 

 Neither under such physical aspects need it be^any longer con- 

 sidered paradoxical to ascribe the polar tendency of the " braA-e 

 west Avinds " to rarefaction by heat in the antarctic circle. This 

 heat is relative, and though it be imparted to air far beloAV the 

 freezing-point, raising its temperature only a few degrees, its 

 expansive power for that change is as great when those few 

 degrees are Ioav down as it is Avhen they are high up on the 

 scale. If such condensation of vapour do take place, then 

 liberation of heat and expansion of air must follow, and con- 



