HISTORICAL SKETCH. 101 



i86S, Warren.] 



drained the valley of lake Winnipeg ; 3rd, that lake Winnipeg for- 

 merly had a great extension southward, according to the opinion of 

 Prof. Henry Youle Hind ;* and 4th, that the most plausible hypothesis to 

 account .for the former drainage of the Winnipeg basin along the valley of 

 the Mississippi, and for the change to the present outlet by Nelson river, is 

 a subsidence of the northern part ot the valley and an elevation of the 

 southern part, extending through a vast period of time, and probably still 

 going on. He refers to the hypothesis that as the glacial epoch tempered 

 off gradually into the present epoch, there might have been a long time 

 when the glaciers had sufficient extension southward to close the outlet to 

 Hudson's .bay, which on the further recession of the ice, would be opened 

 and the lake drained off toward the north. This hypothesis he regards as 

 " unsupported, and barren of any fruit." He thinks it does not explain any 

 phenomena presented by other lake-basins and water-courses in North 

 America, nor enable us to predict what probable results we should find in 

 other regions, and thus intelligently direct further investigation. He then 

 mentions topographic features reported at numerous points in the United 

 States and in the British possessions in America which seem to confirm the 

 former hypothesis ; and closes with a map showing a restoration of the 

 ancient basin of the Mississippi. In this the source is shown to be a stream 

 joining lake Winnipeg from the northwest. Lake Winnipeg is enlarged to 

 exceed the area of lake Superior, extending to Big Stone lake, having its 

 outlet by way of the Minnesota into the Mississippi ; while at the same 

 time an arm of the gulf of Mexico brings salt water up the great valley as 

 far as the parallel on which Chicago lies, and farther still up the Missouri 

 valley, the Ohio itself being an eastward extension from this arm nearly 

 to Pittsburg. 



In the proper place this subject will be fully discussed. It is only 

 necessary to say here that the investigations of the survey, while sustain- 

 ing all Gen. Warren's observations respecting the extension of a lake for- 

 merly occupying the Winnipeg and Red river valley, and the large size of 

 the ancient Minnesota, warrant the hypothesis which he rejects, rather 

 than the one which he adopts. 



Narrative of the Canadian Red river exploring expedition of 1857, and of the Assinibolne and Saskatchewan 

 oxploring expedition of 1858. By Henry Youle Hind. Two volume*. 



