DYNAMICAL GEOLOGY. 23! 



term " Drift " then came to be applied to the same deposits 

 which had been previously termed "Diluvium" (ante, p. 114); 

 and both terms are retained in popular use as synonyms of the 

 more technical term " Pleistocene," introduced by Sir Charles 

 Lyell. 



A young Russian geologist, Bothlingk, published in 1839 a 

 paper of exceptional interest descriptive of the "diluvial or 

 Pleistocene deposits " in Finland and Lapland. In his opinion, 

 the greater mass of the "diluvium" had virtually been de- 

 posited by floods, but the erratic blocks could only have been 

 transported by ice. His work helped to bring the "Drift 

 Theory" into favour on the Continent, and comparatively few 

 of the leading geologists in Europe at that time lent a willing 

 ear to the ice theory of Swiss geologists and their conception 

 of a continuous ice-sheet, or glaciers hundreds of miles long. 



The departure of Agassiz for North America in 1847 took 

 away from Europe the best-known and most powerful exponent 

 of glaciation, and a period of stagnation ensued in glacial 

 geology. 



Seven years passed, and another enthusiastic glacialist took 

 the place of Agassiz in European literature. Sir Andrew 

 Ramsay 1 not only proved the former glaciation of Scotland 

 and Wales, but recognised traces of two Ice Ages in the con- 

 stitution of the breccias and pebble-beds of Malvern and 

 Abberley. He also found evidence of glacier action in the 

 Permian period, and this raised anew the questions of climatic 

 periodicity and ice erosion. Venetz and Morlot had been of 

 opinion that during the diluvial epoch all the greater areas of 



1 Andrew Crombie Ramsay, born 1814, in Glasgow, was intended for a 

 merchant's career, when, on the publication in 1841 of his excellent treatise 

 on the geological formation of the island of Arran, De la Beche secured 

 him as assistant for the geological survey, with which Department he was 

 connected for forty years, first as survey geologist, then as local director, 

 and, after Murchison's death in 1871, as General Director. At the same 

 time he discharged his duties as Professor of Geology at the School of 

 Mines in London. Ramsay was ranked as the best field geologist in Great 

 Britain. His principal work is a geological description of North Wales, 

 which appeared in two editions (1866, 1881). He also published a geo- 

 logical map of England and Wales, 1859; fifth edition, 1881. Besides his 

 official duties, Ramsay occupied himself much with the problems of physical 

 geography and dynamical geology. His Text-book of the Physical Geology 

 and Geography of Great Britain appeared in five editions between 1864 

 and 1878. (Comp. Sir Arch. Geikie, Memoir of Sir Andrew Crombie 

 Ramsay t London, 1895.) 



