BRITISH ASSOCIATION. 



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constituted the prey of the lions, bears, hyenas, wolves, &c., 

 which CO- existed in Great Britain, with gigantic deer and 

 oxen, rhinoceroses, hippopotamuses, elephants, and, still 

 stranger pachyderms, in the antediluvial and tertiary periods. 



On the Action of the North American Lakes, by Mr, 

 Schoolcraft, 



Mr. Schoolcraft's observations on the American lakes 

 were made during a residence of nearly twenty years 

 in that district, chiefly in the immediate vicinity of Lake 

 Superior, and he was thus enabled to devote particular 

 attention to the action of the lakes on their boundaries, 

 under fluctuations of level, by which they have been either 

 considerably enlarged, or otherwise modified. In this 

 respect Lake Superior, perhaps, affords more scope for 

 observation than any other ; its large area and great com- 

 puted depth, serve more fully to develope the action of its 

 waves upon the sandstone rocks which surround its southern 

 margin. This is nowhere better shown than along the twelve 

 miles of mural coast locally known as the pictured rock; the 

 force of the waves, impelled by the equinoctial gales, has 

 fretted and riddled these rocks into the most singular archi- 

 tectural forms colossal caverns, into which large boats can 

 enter, are formed under the impending rock. Along this 

 coast of winding bays and headlands, extending altogether 

 450 miles, the action of heavy currents has broken and 

 comminuted the sandstone and greywacke, piling up the sand 

 thus formed into elevated ridges, or spreading it out over 

 wide plains. The most extensive field of action occurs be- 

 tween the eastward termination of the primary rocks, near 

 Granite Point, and their reappearance in the elevated moun- 

 tainous range of Gros Cape, at the head of St. Mary's 

 Straits. Vast hills, or dunes of sand, 300 feet in height, are 



