112 DISCUSSIONS IN CLIMATOLOGY. 



off the surface, and as soon as the weight of the 

 sheet became less than that of the water which 

 it had displaced, the sheet would float. After this 

 it would no doubt shortly break up and become 

 dispersed. 



Other Causes than Antarctic Ice affecting the 

 Northward- flowing Currents. — If we consider the 

 effect which the present amount of eccentricity, 

 small as it is, has on the climatic condition of some 

 parts of the southern hemisphere, we shall readily 

 understand how, during the glacial epoch, the warm 

 water of this hemisphere may have been impelled 

 northward, even independently of the influence of 

 the Antarctic ice. In order to show the present effect 

 of eccentricity on climate, I cannot do better than 

 quote Mr. Wallace's own words on the subject. 

 Referring to its effect on south temperate America, 

 he says : — 



"Those persons who still doubt the effect of winter in 

 aphelion with a high degree of eccentricity in producing 

 glaciation, should consider how the condition of south 

 temperate America at the present day is explicable if they 

 reject this agency. The line of perpetual snow in the 

 southern Andes is so low as 6000 feet in the same latitude 

 as the Pyrenees ; in the latitude of the Swiss Alps, moun- 

 tains only 6200 feet high produce immense glaciers which 

 descend to the sea-level; while in the latitude of Cumberland, 

 mountains only from 3000 to 4000 feet high have every 

 valley filled with streams of ice descending to the sea-coast 

 and giving off abundance of huge icebergs. Here we have 

 exactly the condition of things to which England and 

 Western Europe were subjected during the latter portion 

 of the glacial epoch, when every valley in Wales, Cumber- 

 land, and Scotland had its glacier; and to what can this 

 state of things be imputed, if not to the fact that there is 

 now a moderate amount of eccentricity, and the winter of 



