120 Packing of the Ice. 



ice, and a consequent security against any further rise of the river 

 to loosen its covering for any further movement. The opening 

 is thus a true mark of safety. It lasts the whole winter, never 

 freezing over even when the temperature of the air reaches 30° 

 below zero of Fahrenheit ; and from its first appearance the waters 

 of the inundation gradually subside, escaping through the channel 

 of which it is the index. The waters seldom if ever however fall 

 so low as to attain their summer level ; but the subsidence is suffi- 

 ciently great to demonstrate clearly the prodigious extent to 

 Avhich the ice has been packed, and to show that over great occa- 

 sional areas it has reached to the very bottom of the river. For 

 it will immediately occur to every one, that when the mass rests 

 "on the bottom its height will not bediminished by^the subsidence 

 of the water, and that as this proceeds, the ice, according to the 

 thickness which it has in various parts attained, will present 

 various elevations after it has found a resting-place beneath, until 

 just so much is left supported by the stream as is sufficient to 

 permit its free escape. When the subsidence has attained its 

 maximum, the trough of the St. Lawrence therefore exhibits a 

 glacial landscape, undulating into hills and valleys that run in 

 various directions, and while some of the principal mounds stand 

 upon a base of 500 yards in length, by a hundred or two in 

 breadth, they present a height of ten to fifteen feet above the level 

 of those parts still supported on the water. 



On the banks of the St. Lawrence, in the neighbourhood of 

 Montreal, there is an immense collection of boulders, chiefly from 

 rocks of igneous origin, and among them syenite greatly abounds. 

 They are of all sizes, but many are very large, and multitudes 

 must be tons in weight. From their appearance above the surface 

 in shallow parts of the river it is very probable the bed of it teems 

 with them also ; and it is remarked by the inhabitants that the 

 positions of these boulders, both in the river and on the banks, 

 frequently appear changed after the removal of the ice in the 

 spring. I spent several days in the autumn of last year examin- 

 ing the boulders along shore, all the way from Montreal to La- 

 chine, a distance of nine miles; and on again looking at them in the 

 spring I missed some which had particularly attracted my atten- 

 tion, but as I had not mapped their positions I may inadvertently 

 have passed them over. But when we consider the manner in 

 which the ice packs and subsequently moves, it cannot fail to ap- 

 pear a very probable agent in transporting these blocks. Closely 



