1909.] Ice on Canadian Lakes. 15 



When I crossed Lake Winnipeg in December, 1893, it had been frozen 

 with a smooth surface, and had remained in that condition, so that we 

 travelled over it in our dog-sleighs with ease and comfort; but when I 

 travelled down the same lake in the following year it had evidently been 

 frozen over early in the autumn, the ice had afterwards been broken up 

 by a heavy storm and it had frozen again with the jagged points and edges 

 of the masses of ice projecting in every direction, so that it was quite 

 impossible for us to take a straight course over the ice as we had done in 

 the previous year. In consequence of this we were obliged to keep to the 

 shore and to follow all its bays and indentations, which made our journey 

 very much longer and more arduous. The irregularities in the surface of 

 the ice would in time be filled with the snow which had been constantly 

 drifted over it, and it is quite likely that towards the end of winter the 

 general surface would have been rendered flat and regular. In that case 

 it might be impossible to say that the ice had not frozen quietly, except 

 that it would be a foot or two thicker than usual and that it would not 

 have its usual regular structure. 



The Yukon River furnishes some of the best examples of rough ice 

 to be seen on any of our inland waters. Every year after the ice freezes, 

 parts of it break up again and the broken masses are carried down by the 

 current and piled up against the smooth unbroken ice which remains 

 here and there across the river. Thus an ice-jam, sometimes many 

 miles in length, may be formed, and as this freezes into a solid mass it 

 makes a very rough irregular surface over which it is difficult to travel 

 with sleighs or even on foot. (See Plate VI.) 



The old winter trail from Skagway to the Klondike used to run down 

 the Yukon River. The smooth unbroken ice made an excellent road, 

 but when the broken and refrozen ice was encountered it was found 

 practically impossible to travel over it and it was often necessary to search 

 out a trail through the woods on one side or the other of the river, perhaps 

 for several miles at a time, in order to find some easy way around the 

 rough ice. 



The rains, common in the autumn, usually raise the water in the lakes 

 and rivers to a high stage about the time that the severe cold of winter 

 sets in, and that the ice begins to form. After the ice has formed and the 

 winter has set in, almost all the moisture that falls on the surface of both 

 the land and water falls as snow. A small portion of this snow evaporates 

 into the air, but the greater portion of it remains and accumulates on the 

 surface of the ground throughout the winter. It thus gives rise to a set 

 of conditions which differ materially from those which prevail during the 



