GRAND LAKE, CAPE BRETON. BRODIE. 255 



nearly level country, and occasionally along hillsides, where, 

 had they been absent, the hill itself would have served as a dam. 

 Further, I have found no sticks of timber in any diggings or 

 cuttings that I have examined. 



Mounds somewhat resembling these are ascribed to glacial 

 formation. Streams flowing beneath the ice of modern glaciers 

 are loaded to the limit of carrying capacity with morainic 

 material. This is deposited at the bottom of the ice tunnel, and 

 on the final recession of the glacier there is left a sinuous heap 

 of clay, gravel and boulders, to which the name of esker is 

 given. Such mounds found throughout Canada and the north- 

 ern United States are considered to be the work of Pleistocene 

 ice. 



But the sub-glacial stream seeking a lower level would 

 scarcely bend upon itself in such fashion as shown in the accom- 

 panying blue print. 



Further, in such a long stream it would surely enlarge its 

 cavern at some points, say where it was obstructed by large 

 boulders, and there spread its load in wide heaps. Although 

 the mounds at Grand lake ramify for short distances, there are 

 no such widenings as might be expected as above. Again the 

 uniformity in height argues against the esker theory. 



At the present margin of the lake there are narrow gravel 

 beaches. On one occasion in midwinter, after a thaw of a few 

 days' duration followed by sharp frost, I noticed that the ice 

 in tne lake had pushed against this frozen mass of pebbles. The 

 surface layer, cemented by frost, had buckled under the ice 

 pressure in the form of a ridge, a few inches in height. I have 

 a small photo attached showing this. The question .arises, could 

 the large mounds have been formed by the same agency as these 

 small ones? I made several visits to the lake to observe any 

 upbuilding comparable with the mounds in question. I could 

 not find any effects of modern ice shove at all approaching in 

 size the mound under discussion. 



