376 THE GREAT ICE AGE 



easiest flow ; that this theory does no violence to the analogy 

 of the existing order of things, requiring merely an enlargement 

 of actual glaciers by the intensification of actual conditions : 

 that abundant evidence can he obtained, as, for example, from 

 Switzerland, that the present glacier system of the earth was ^ 

 once of sufficient magnitude to produce all the observed 

 phenomena ; that the most important glacial radiants in the 

 northern hemisphere were, in North America, the district 

 round Hudson Bay, New England and the Adirondacks, with 

 certain areas in the western Cordilleras, and in Europe the 

 Norwegian Dovrefelds and the Alps, Asia apparently possess- 

 ing none of commensurate importance; that it satisfactorily 

 explains, also, the previously puzzling absence of glacial action 

 over the great plain of Siberia, the coldest portion of the 

 northern temperate zone ; that the belief in a vast polar ice cap, 

 thousands of feet thick, covering the whole Arctic region, and 

 extending almost continuously down to low latitudes, is an as- 

 sumption doing violence to observed physical facts and to 

 probability, that it is not required to account for the pheno- 

 mena, and is, in fact, contradictory to some of them." 



In Europe there is equally good evidence of the existence of 

 huge glaciers on the Scandinavian mountains and the Alps, 

 and of lesser accumulations of ice on the hills, as, for instance, 

 those of the British Islands ; but the Scandinavian boulders 

 scattered over the plains of Great Britain must have been 

 water borne. ^ 



In connection with these extracts I would observe that the 

 writer, and those with whom he has acted in this matter, have 

 never held that icebergs alone, or fields of ice alone, have pro- 

 duced the Pleistocene deposits. Their contention has been 

 that the period was one in which glaciers, icebergs, and field 



1 The reports of the Scottish boulder committee, and Lapworth's recent 

 careful examination of the deposits on the East of England [Journ. Geol. 

 Soc, Aug., 1891), strongly confirm me in this opinion. 



