Through a Forest 137 



feet to two miles in diameter. There are about 

 fifty of them within the range of my excursions. 

 Island Lake is in places one hundred feet deep, or 

 one hundred and forty feet below the top of the 

 island. I think I have come upon the process of 

 the formation of these bowls. This sand is rock 

 ground up by glacial action upon a rough, moun- 

 tainous country. The ice, estimated to have been 

 from one to two thousand feet thick, would make 

 for itself a level road-bed, filling the depressions in 

 the rocks with ice, the glacier sliding over the thus 

 rock-locked ice masses. Now if we suppose that 

 this lake has, by the action of wind-drifted and rain- 

 washed sand, filled up one-half, then we should 

 have the original depression to be at least two hun- 

 dred and forty feet. When the ice-sheet slowly 

 retreated northward, we should have here a mass 

 of ice reaching that depth below the general level, 

 and while it lasted, prevented the water from filling 

 with silt the depression which it occupied. These 

 rock-locked masses of ice would be the last to melt, 

 and by the time they were gone, the glacial flood 

 would have subsided, leaving the further modifica- 

 tion of the surface to the slow action of wind, rain, 

 and vegetation. 



The nonchalance of wild animals on their escape 

 from danger is a prominent element in their happi- 

 ness. When the danger is past, immediately they 

 give themselves no more concern about it. We 

 had an illustration of this one bright moonlight 



