678 MR DAVID MILNE HOME ON THE BOULDER-CLAY OF EUROPE. 



Dr Hayes, in his account of a visit to the West Coast of Greenland in 1867,* 

 says, " where the current is swift, and the ice is pressed down upon the land with 

 great force and rapidity, the rocks are worn away until they are as smooth and 

 polished as the surface of a table.'''' The bearing of this remark on the innumer- 

 able smooth and polished rock surfaces in Scotland and the north of England 

 needs not be pointed out. 



Dr Hayes mentions another effect of floating ice. He says that " a shelf of 

 ice glued to the shore forms a winter girdle of all the Arctic coasts. It is 

 usually broken away towards the close of every summer, when the masses of 

 rock which have been hurled down upon it (during the previous eight months) 

 from the cliffs above are carried away and dropped in the sea. The amount of 

 rock thus transported is immense ; and yet it falls far short of what is carried by 

 icebergs' 1 " 1 (p. 403). 



Much to the same effect, on both of these points, Dr Wallich mentions that, 

 when dredging off Labrador at a depth of from 10 to 15 fathoms, he found the 

 sea-bottom to consist "wholly of uncovered rock or of boulders" — "owing (as he 

 adds) to the long continued action of drift ice and currents" f 



Another effect produced by floating ice has been observed — the formation of 

 ruts and stria? on the smooth surfaces of rocks. Many competent observers 

 have given evidence on this point.:): 



The foregoing statements refer to what is now seen going on, wherever there 

 are icebergs and icefloes, and they show that these agents, if they existed in 

 Scottish seas, at a former epoch of the world, must have had the power of pro- 

 ducing most of the phenomena connected with our pleistocene deposits. 



It is not unimportant to remark, in further confirmation of this view, that in 

 the Arctic regions there exist boulder-clay and boulders pretty high above the sea, 

 just as in Scotland, and that all the Arctic travellers who have paid attention to 

 the subject do not doubt that the chief agents in producing them were icebergs 

 and shore ice. 



Thus Dr Sutherland found in Barrow's Straits, up to a height of about 

 1000 feet, great numbers of boulders, all (he says) clearly transported by coast- 

 ice previous to the elevation of the land, — just as he saw them being transported 

 in that way along the existing shore of Greenland. 



Mr Lamont, in his Memoir on Spitzbergen, takes notice of several places 

 where icebergs had evidently left their footprints, when the land was submerged. 

 At one spot, about 20 feet above the present sea-level, he found a trench, about 

 100 yards long by 3 or 4 feet deep, formed among boulders, and caused, as he 

 believed, by an iceberg drifting through them. At another spot, he found what 



* The Open Polar Sea. f North Atlantic Sea-Bed, p. 40. 



J Sir Charles Lyell — (1) Travels in North America, vol. ii. p. 173; (2) Load. Geolog. Journal 

 for 1849, Trapolli in Scandinavia ; Lond. Geolog. Journal for 1868, xcviii. 



