tHE HAMILTON ASSOCIATION. 135 



of the eastern townships, the Gaspe peninsula and the north shore. 

 The lower-lying parts of Vermont, the whole of middle and western 

 New York, northern Pennyslvania, a great part of Ohio, Indiana, 

 Missouri and Michigan, leaving out other more remote provinces 

 and states, would be buried under the waters of a lake whose 

 probable boundaries would be the Laurentides on the north, the 

 Adirondacks, and including Lake Champlain, the Green Mountains 

 on the east, the Gatskills and other Appalachion chains on the south- 

 east,, certain north-facing escarpments in Ohio and Indiana to the 

 north, and certain other escarpments of Wisconsin on the west. 

 That such a submergence did take place has been ably shown by 

 the researches of Dr. Spencer, who has placed the existence of the 

 resulting lake beyond a doubt, and has named it in honor of the 

 famous American geologist, Lake Warren. By a succession of 

 differential uplifts to the north and the east, the three areas of 

 Western Ontario mentioned in the preceeding paragraphs were up- 

 heaved, leaving us when the St. Lawrence was lowered tn its 

 present level, our lake system as we understand it to-day. The 

 movement of uplift was probably slow and gradual since we pass 

 almost imperceptibly from area to area. Such area, too, is not of 

 uniform level, the first varying from nine hundred to fourteen 

 hundred feet in height above Lake Ontario, the second from five 

 hundred to eight hundred, the third from three hundred and twenty 

 to five hundred. As each area was separated from the great lake it 

 became a subordinate sheet of fresh water ponded back by gravel 

 ridges and by the escarpment ; a body of water from which issued 

 in greater volume than at present the streams which have carved out 

 the river-valleys above described. As time went on the silting up 

 of these bodies of water caused the formation of marshes and 

 swamps, and the isolation of the lakelets before mentioned ; in other 

 words, each became in turn from a noble sheet of water, a tract of 

 bog and swamp, with lakelets dotting the surface here and there. 

 Finally, man appeared on the scene, and by stripping the country of 

 forest and draining the land, reduced the volume of the streams to 

 their present size. 



There remain two questions to be answered. The first is that 

 since the escarpment front offers the highest barrier to these 

 swamps, why the creeks described have forced their way through the 

 rock, rather than through the gravel ridges. The answer to this is 



