4 "6 Proceedings. 



the Glacial Period. It is the fashion of the philosophy of the day to ascribe 

 much of the moulding of our hills and valleys to the denuding power of ice 

 more in fact than one is inclined to admit. 



Professor Phillips, at a late meeting of the British Association, remarked 

 that one is almost frozen to silence in presence of the vast sheets of ice which 

 some of his friends, followers of Agassiz, believe themselves to have traced 

 over the mountains and vales of a great part of the United Kingdom. He 

 refuses to accept the proposition that these "ice-rubbers" plough out the 

 valleys and lakes, until we possess more knowledge than has yet been attained 

 regarding the resistance offered by ice to a crushing force, seeing that under 

 a column of its own substance 1000 feet high it would not retain its 



solidity. 



I have alluded to Phillips' opinion, because I see in Geikie's late work 



m 



This 



streams of water issue and unite to form considerable rivers, one of which, 

 after a course of forty miles, enters the sea with a mouth nearly three-quarters 

 of a mile in breadth— the water flowing freely at a time when the outside sea 

 was thickly covered with ice. 



flow of water, Geikie thinks, probably circulates to some extent 

 below every glacier, and he accounts for it by the liquefaction of ice from the 

 warmth of the underlying soil. I am sure you will find a more natural 

 solution of this flow of water from glaciers— estimated not less than 3000 

 feet thick— in the suggestion first made by Professor James Thomson, and 

 subsequently proved by hia brother, Professor W. Thomson, that the freezing 

 point of water is lowered by the effect of pressure 0-23° Fahr., or about 

 a quarter of a degree for each additional atmosphere of pressure. Now, a 

 sheet of ice 3000 feet thick is equal to a pressure of eighty-three atmospheres, 

 at which pressure it would require a temperature of 19 

 point to retain the form of ice. In the state of nmt.ii 



below 



g water below 



glacier, it might readily, as Geikie states, absorb heat f__„ _„_ D 



soil sufficient to retain its liquid form, as the overlying weight gradually 

 lessened at the edge of the glacier. In this, too, we have a safe assurance that 



enormous 



inclination of the land 

 tnous thickness could i 



mountain 



And this ma 

 Swiss glacialists 



run 



having existed in the great Ice Age not less than 3000 feet thick, overtopping 



Valley 



