432 W. UPHAM ESKER NEAR WINNIPEG, MANITOBA 



slope of Birds Hill, for about a mile, are covered with till and boulders, 

 while they are absent from the top and south slope, they seem impossible 

 to be ascribed to an unmelted arch of the ice-margin inclosing the glacial 

 river in a tunnel, but to be due to a slight readvance of the ice-front from 

 the north side of the glacial river. 



The conclusion that there was much englacial drift, which became 

 exposed at last on the thinned ice-margin, carries with it the consequent 

 reference of eskers and kames not to subglacial but to superglacial drain- 

 age. Melting of the ice-sheet near its receding boundary at the end of 

 the Glacial period was probably far more rapid than is known anywhere 

 on glaciers and ice-sheets of the present time ; so that any crevasses or 

 moulins would speedily be obstructed by drift carried into them, causing 

 the rivers from the ice melting and rains to flow down on the surface of 

 the ice to its margin. 



