THE " GKEAT ICE AGE." 171 



ing the glacial epoch, to the extent of 600 feet as a minimum, 

 while the well-known deposits of Arctic shells at Moel Tryfaen 

 and the accompanying drift have led Professor Ramsay to esti- 

 mate " the probable amount of submergence during some part 

 of the glacial period atabout 2300 feet." * 



It would be out of place here to reproduce the data upon 

 which geologists have based their rather divergent opinions 

 respecting the actual extent of the submergence of the western 

 coast of North Europe. All agree that a great submergence 

 occurred, but differ only as to its extent, their estimates vary- 

 ing between 1000 and 3000 feet. 



There is one important consideration that must not be over- 

 looked viz. that if my view of the submarine origin of the 

 till be correct, the mere submergence of the land at the glacial 

 period does not measure the difference between the depth of 

 the sea at that and the present time, seeing that the deposits 

 from the glaciers must have shallowed it very materially. 



It is only after contemplating thoughtfully the present form 

 of the granitic and metamorphic hills of Scandinavia hills that 

 are always angular when subjected only to sub-aerial weather- 

 ing that one can form an adequate conception of the magni- 

 tude of this shallowing deposit. The rounding, shaving, 

 grinding, planing, and universal abrasion everywhere displayed 

 appear to me to justify the conclusion that if the sea were now 

 raised to the level of the terraces i.e. 600 feet higher than at 

 present the mass of matter abraded from the original Scandi- 

 navian mountains, and lying under the sea, would exceed the 

 whole mass of mountain left standing above it. 



The first question suggested by reading Mr. Geikie's book 

 was whether the terraces are wholly or partially formed of till, 

 and more especially whether their lower portions are thus com- 

 posed. This, as already stated, was easily answered by the 

 almost unanimous reply of all the many Norwegian valleys I 

 traversed. Any tourist may verify this. The next question 

 was whether this same till extends below the sea. This was 

 not so easily answered by the means at my disposal, as I 

 travelled hastily round the coast from Stavanger via the North 

 Cape to the frontier of Russian Lapland in ordinary passenger 

 steam-packets, which made their stoppages to suit other re- 

 quirements than mine. Still I was able to land at many sta- 

 tions, and found, wherever there was a gently sloping strand 



* Lyell, " Elements of Geology," p. 150. 



