FAILURE OF CLIMATIC THEORIES. 7 



the requisitions of dynamical mathematics for an alteration 

 of even as much as two or three degrees in the earth's axis 

 in what may be practically called 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 

 as on the other side of the pole.* 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."f 



In the memoir from which the preceding paragraph 

 is quoted, Sir William maintains that an increase in 

 the amount of heat conveyed by ocean currents to the 

 Arctic regions, combined with the effect of Clouds, 

 Wind, and Aqueous Vapour, is perfectly sufficient to 

 account for the warm and temperate condition of 

 climate which is known to have prevailed in those 

 regions during the Miocene and other periods. 



Now, this is the very point for which I have been 

 contending for many years. The only essential differ- 

 ence between Sir William's views and mine is simply 

 this : He accounts for an increase in the flow of warm 

 water to the Arctic regions by a submergence of the 

 circumpolar land, whereas I attribute it to certain 

 agencies brought into operation by an increase in the 

 eccentricity of the earth's orbit. Such geological 

 evidence as we possess of warm episodes in the 



* This has been proved to be the case by Professor Haughton, 

 " Nature," July 4, 1878. 



f "Trans, of Geol. Soc. of Glasgow," Feb. 22, 1877. 



