(Blacial anfc preglacfal SLafces, 229 



much larger than any of our greatest lakes. 

 The shores of this lake the bed of which is 

 now dry land and the heart of a great agricul- 

 tural region are well defined and have been 

 surveyed and mapped out. When this great 

 body of water was released it was to the north- 

 ward. For this reason it was undoubtedly 

 held for a much longer time than some of the 

 lakes to the southward where the ice melted 

 sooner. 



