16 REPORT 1892. 



of the land. By others they were attributed to the strong tides and 

 •currents of the sea when the land stood at a lower level. The uniformi- 

 tarian school of Lyell had no difficulty in elevating or depressing land 

 to any required extent. Indeed, when we consider how averse these 

 philosophers were to admit any kind or degree of natural operation other 

 than those of which there was some human experience, we may well 

 wonder at the boldness with which, on sometimes the slenderest evidence, 

 they made land and sea change jDlaces, on the one hand submerging 

 mountain-ranges, and on the other placing great barriers of land where 

 a deep ocean rolls. They took such liberties with geography because 

 only well-established processes of change were invoked in the operations. 

 Knowing that during the passage of an earthquake a territory bordering 

 the sea may be upraised or sunk a few feet, they drew the sweeping 

 inference that any amount of upheaval or depression of any part of tho 

 earth's surface might be claimed in explanation of geological problems. 

 The progx'ess of inquiry, while it has somewhat curtailed this geo- 

 graphical license, has now made known in great detail the strange story 

 of the Ice Age. 



There cannot be any doubt that after man had become a denizen of 

 the earth, a great physical change came over the northern hemisphere. 

 The climate, which had previously been so mild that evergreen trees 

 flourished within ten or twelve degrees of the north pole, now became so 

 severe that vast sheets of snow and ice covered the north of Europe and 

 crept southward beyond the south coast of Ireland, almost as far as the 

 southern shores of England, and across the Baltic into Prance and 

 Germany. This Arctic transformation was not an episode that lasted 

 merely a few seasons, and left the land to resume thereafter its ancient 

 aspect. With various successive fluctuations it must have endured for 

 many thousands of years. When it began to disappear it probably 

 faded away as slowly and imperceptibly as it had advanced, and when 

 it finally vanished it left Europe and North America profoundly changed 

 in the character alike of their scenery and of their inhabitants. The 

 rugged rocky contours of earlier times were ground smooth and polished 

 by the march of the ice across them, while the lower grounds were 

 buried under wide and thick sheets of clay, gravel, and sand, left 

 behind by the melting ice. The varied and abundant flora which 

 had spread so far within the Arctic circle was driven away into more 

 southern and less ungenial climes. Bat most memorable of all was 

 the extirpation of the prominent large animals which, before the advent 

 of the ice, had roamed over Europe. The lions, hyisnas, wild horses, 



