CHAPTER IV 



THE ICE AGE AND ITS WORK 

 I. ERRATIC BLOCKS AND ICE-SHEETS 



It is little more than fifty years ago that one of the most 

 potent agents in modifjdng the surface-features of our 

 country was first recognised. Before 1840, when Agassiz 

 accompanied Buckland to Scotland, the Lake District, and 

 Wales, discovering everywhere the same indications of the 

 former presence of glaciers as are to be found so abundantly 

 in Switzerland, no geologist had conceived the possibility 

 of a recent glacial epoch in the temperate portion of the 

 northern hemisphere. From that year, however, a new 

 science came into existence, and it was recognised that 

 only by a careful study of existing glaciers, of the nature 

 of the work they noAv do, and of the indications of the 

 work they have done in past ages, could we explain many 

 curious phenomena that have hitherto been vaguely re- 

 garded as indications of diluvial agency. One of the first- 

 fruits of the new science was the conversion of the author 

 of Ediqiticv Diliiviancc — Dr. Buckland, who, having studied 

 the work of glaciers in Switzerland in company with 

 Agassiz, became convinced that numerous phenomena he had 

 observed in this country could only.be due to the very same 

 causes. In November, 1840, he read a paper before the 

 Geological Society on the " Evidences of Glaciers in Scot- 

 land and the North of England," and from that time to the 

 present the study of glaciers and of their work has been 

 systematically pursued with a large amount of success. 



