336 EARTH FEATURES AND THEIR MEANING 



(Fig. 365). The level of the waters was lowered and the area 

 of the lakes correspondingly reduced. 



The reader who has had no opportunity to observe these an- 

 cient channels which carried the swollen waters of the former 

 glacier lakes, will find it interesting to consider that every one of 

 them has been fixed upon by engineers for improvement as arti- 

 ficial waterways. Thus we have the Illinois Drainage Canal 

 and projected ship canal along the " Chicago outlet," the pro- 

 jected Mississippi-Lake Erie Canal along the " Fort Wayne out- 

 let," the Grand River canal project to connect Lake Michigan and 

 Saginaw Bay along the course of the " Grand River outlet," the 

 Trent Canal along the " Trent outlet," the Erie Canal along the 

 " Mohawk outlet," and, lastly, the proposed Georgian Bay ship 

 canal to the ocean along the " North Bay" or " Nipissing outlet." 



Summary of lake stages. We have omitted in this sum- 

 mary of late lake history in the Laurentian basin all the less 

 important lake stages, including some of a transitional nature 

 which were represented by beaches and outlets easily traced to- 

 day. This is because it is an outline only which it seems best to 

 present, and the episodes of this abridged history may be tabu- 

 lated as follows : 



EPISODES OF GLACIAL LAKE HISTORY 

 MISSISSIPPI DRAINAGE 



Lake Maumee (early), Fort Wayne outlet. 



Lake Maumee (late), Imlay City outlet. 



Lake Arkona, "thumb" outlet. 



Lake Whittlesey (with readvance of glacier), Ubly outlet. 



Lake Warren, '* thumb" outlet. 



ATLANTIC DRAINAGE 



- 



Lakes Iroquois and Algonquin (early) , Trent and Mohawk outlets. 

 Lakes Iroquois and Algonquin (late) , Port Huron and Mohawk 



outlets. 

 Nipissing Great Lakes, North Bay outlet. 



Permanent changes of drainage affected by the glacier. While 

 the lake history which we have sketched is made up of episodes 

 which endured only while the ice front lay between certain- sta- 

 tions upon its retreat, there were none the less brought about the 



