174 NEW YORK STATE MUSEUM 



and upper St Lawrence valleys. Any refinement or revision of 

 the jiroblenis with which this report mainly deals should be 

 be«2:un at Covey hill. The absence of definite shore lines on the 

 smooth till slope of the northern face of this eminence from 570 

 feet to the top is in striking contrast with the wave-ribbed sloj)es 

 of the Champlain valley on the south at an equal elevation. 

 Except for one or two faint traces of parallel roads and a small 

 delta on the north slope at an elevation not far from 800 feet 

 the till slope of the upper half of the hill is practically as left 

 by the ice sheet. The failure of beaches and cliffs due to the 

 work of waves in this upper zone just where waves would be 

 most effective had an open body of water been present to transmit 

 the undulations of its surface against this impressionable glacial 

 coating is one of the most conclusive arguments for the theory 

 of glacial barriers. I have already described the corroborative 

 evidence as to the upper limit of standing water in glacial lakes 

 found in the abandoned spillway and waterfall of the Gulf. 



