PART I. CHAPTER VI. 



87 



Erratic Blocks drifted by Ice. 



with them again in Chili and Patagonia, between lat. 41^ S. and 

 Cape Horn.* Here, then, we have grounds for suspecting that 

 a cold climate is favourable to the production of erratics. 



Now it is well known, that, annually, in the Baltic, stones are 

 moved by ice ; and, very recently, on the shores of the Gulf of 

 Finland, some large fragments were ascertained to have been 

 carried to some distance. In spring, when the fringe of ice 

 which has encircled the coast of the Gulf of Bothnia, and many 

 parts of Sweden, Norway, and Denmark, during winter, breaks 

 up, large stones, with small gravel and ice, which have been 

 firmly frozen into a solid mass on the beach, are floated off to a 

 distance. In Canada similar operations, but on a grander scale, 

 have been noticed by Captain Dayfield. In the river St. Law- 

 rence, the loose ice accumulates on the shoals during v/inter, at 

 which season the water is low. The separate fragments of ice 

 are readily frozen together in a climate where the temperature is 

 sometimes 30o below zero, and boulders become entangled with 

 them, so that in the spring, when the river rises, on the melting 

 of the snow, the packs are floated off, frequently conveying away 

 the boulders to great distances. A single block of granite, 15 

 feet long, by 10 feet both in width and height, and which could 

 not contain less than 1500 cubic feet of stone, was in this way 

 moved down the river several hundred yards, during the late 

 survey in 1837. Heavy anchors of ships, lying on the shore, 

 have in like manner been closed in and removed. In October, 

 1836, wooden stakes were driven several feet into the ground, at 

 one point on the banks of the St. Lawrence, at high water mark, 

 and over them were piled many boulders, as large as the united 

 force of six men could roll. The year after, all the boulders had 

 disappeared, and others had arrived, and the stakes had been 

 drawn out and carried away by the ice. 



It has also been observed, that ice-islands, detached far to the 

 north, perhaps in Baffin's Bay, are brought by the current, in 

 great numbers, down the coast of Labrador every year, and are 

 often carried through the straits Qf^'Belle Isf^^between N'gW- 

 foundland and the coniii?£Pi^e)f America, which, after passing 

 through the. st-raitsr sometimes float for several hundred miles to 

 the -southwest, up the Gulf of St. Lawrence, between the 40th 

 and 50th degrees of N. latitude. In one of these icebergs, 

 heaps of boulders, gravel, and stones were seen. 



A similar agency of ice extends in the southern hemisphere to 

 still lower latitudes. Thus, for example, we learn from Mr. 

 Darwin, that glaciers reaching down to the sea, occur at the 



* Darwin, ibid. 



