106 THE ICE AGE IN CANADA. 



very clearly what may be effected by floating ice impinging 

 on shores : 



"Having learnt that you took much interest in the 

 transportation of boulders by ice, I venture to mention a 

 peculiar mode in which this is done, which I have not 

 seen noticed elsewhere. 



"When at Eepulse bay in 1846-7, I noticed in the 

 spring that large boulders, some of them more than three 

 feet in diameter, gradually appeared on the surface of the 

 sea-ice near shore, as the ice wasted away by thaw and 

 evaporation. Although I wondered how this was done, I 

 had no opportunity of proving it until wintering at the 

 same place in 1853-4. 



" First let me say that the rise and fall of the tide is 

 from eight to ten feet, sometimes more, and that the ice 

 on Eepulse bay attains a thickness of about eight feet. 



" Suppose, then, that a boulder of a good size, say 3 J 

 feet diameter, is lying on the shore, at, or farther out 

 than low-water mark, in the beginning of winter, when 

 the ice is forming, it comes in contact with the boulder at 

 low water, and the boulder breaks through it ; but when 

 the ice becomes two feet or so thick, the boulder freezes 

 to it, and is lifted with the ice when the tide rises. This 

 continues all winter, the ice increasing in thickness to 

 eight feet, soon encloses the boulder inside of it, and 

 having about four feet of solid ice below. Boulders may 

 thus be carried hundreds of miles. 



" There is another phase in connection with this matter. 

 Supposing boulders are lying in five or six feet of water 

 or less when it is low water, these boulders would get 

 frozen to the lower surface of the ice, and get set into it 

 as a diamond is set for cutting glass, and would thus be a 

 good graver of any rocks it might pass over." 



