296 POPULAR LECTURES AM) ADDRESSES. 



geological time shown to be on purely geological 

 grounds exceedingly improbable. But even suppose 

 such a change as would bring ten or twenty degrees 

 of more indulgent sky to the American Arctic 

 Archipelago ; it would bring Nova Zembla and 

 Siberia by so much nearer to the pole : and it 

 seems that there is probably as much need of 

 accounting for a warm climate on one side of the 

 pole as on the other. There is in fact no evidence 

 in geological climate throughout those parts of 

 the world which geological investigation has 

 reached, to give any indication of the poles having 

 been anywhere but where they are, at any period 

 of geological time. 



Pass now from the evidence of a temperate 

 climate, allowing vegetation such as at present 

 lives in the North of Europe, to have lived all 

 over the Arctic islands at a not very remote 

 geological epoch, of which we have found a 

 perfectly satisfactory explanation in Lyell's hy- 

 pothesis of the submergence of the circumpolar 

 .land barriers ; and consider next the evidence, with 



