52 LAKE SUPERIOR. 



I ever saw. I regret that I did not take the girth of one of them, 

 which must have been five feet in diameter. But the black flies and 

 musquitoes wore so annoying as to absorb much of one's attention ; 

 the only refuge was the beach, where we had made fires to drive 

 them off". The heat of the day made a bath very agreeable ; we 

 found the current of the river at the mouth so strong as to make 

 some difficulty in swimming even this short distance across. 



One of the men killed here a squirrel of the kind that takes the 

 place of our" Chipmunk" in these regions, the Tamias quadrivittatus. 

 It resembles our animal, except that it is a little smaller, has a longer 

 tail, and four black stripes instead of three, on its back. We found 

 it afterwards much more abundant than any other species, particu- 

 larly on hill-sides among broken rocks, attracting the attention by its 

 loud, pecuhar cry. 



On the bank was the skeleton of an Indian lodge, and a well-worn 

 trail ran up along the stream. The Indians here as everywhere love 

 the neighborhood of rivers, where we always found traces of their 

 camps. As we left the river we saw some of their handiwork on a 

 rock over the beach. It was the picture of a schooner under sail, 

 scratched out from the black lichens so as to show the lighter surface 

 of the rock. 



The Professor pointed out here the difference of water action from 

 that of ice. The former, he said, leaves the harder parts prominent, 

 although the whole is smoothed, as was the case in this instance, but 

 the latter grinds all down to a uniform surface, scratching it at the 

 same time in straight lines. 



This afternoon, the water being smooth, we tried an experiment as 

 to its transparency, by lowering a tin cup at the end of a fishing-line. 

 It went out of sight at forty- two feet. It is said that when the 

 water is entirely unruffled and the sky clear, a white object may be 

 seen at the depth of one hundred and twenty feet. 



Passing Montreal Island, a large, low island covered with trees, 

 some three or four miles from the shore, we threaded our way through 

 a group of rocky islets and came out into a wide bay, which we trav- 

 ersed,!. e.,took the direct line across, instead of following the curve 

 of the shore. The voyageurs are in general unwilling to keep out more 

 than a quarter of a mile or so, and usually coast along the rocks. But 



