Facts relating to the Great American Lakes, 295 



when we saw sharp-edged stones falling into crevasses, and 

 appearing at the extremity of the glacier rounded, polished, 

 and striated — when we saw the beautifully clear water of the 

 glacial rivulets descending into the same crevasses, and gush- 

 ing from the same extremity a turbid stream, the explanation 

 was before our eyes — the conclusion was irresistible — these 

 were the manufactories of soil. 



Alnwick, 

 3d March 1847. 



Facts relating to the Great North American Lakes* By 

 Professor C. Dewey. 



1. Phenomenon on LaJie Ontario. 



On 20tli September 1845, was witnessed a singular phe- 

 nomenon on Lake Ontario. In the afternoon the waters 

 suddenly moved, in a mass, out of the rivers, bays, coves, 

 harbours, &c., lowering the water to different depths in diffe- 

 rent places. In ten or twelve minutes the waters returned, 

 and rose to a higher level than they had before. This oscilla- 

 tion, or efflux and reflux of the waters, was repeated several 

 times, at about the same interval of eight or twelve minutes. 

 At the mouth of the Genesee river, seven miles from the city, 

 the water fell two feet below its common level, and soon rose 

 as much above it. The Revenue cutter, John Y. Mason, 

 lay in the harbour, and the hands witnessed the fall and rise 

 of the waters. At several places along the neighbouring 

 shores, boats were left for a few moments on the sands. At 

 Oswego, seventy miles east of this, a large body of logs 

 moved out into the lake, to the great annoyance of the owner, 

 till he saw them soon returning to their previous location. At 

 Cobourg, a little west of the Genesee, and on the Canada side 



* OriKinally printed in the Report of the Rpgents of the Univeriiity New 

 York, \n 1846, p. 228, nearly as pr^-parrd by the author for Silllman's Jour- 

 ohI. 



