NE-SAW-JE-WON 



What of the future? Lakes are but ephemeral features of 

 any landscape. The Great Lakes, like all others, are doomed 

 to extinction. Slowly they are filling, slowly their outlets are 

 being lowered, and eventually they will be drained; but as 

 long as the rock sill at Buffalo holds — or until Niagara River 

 cuts back to Lake Erie — the upper lakes will remain as lakes. 

 Measurements of Niagara Falls since 1827 show that the 

 Horseshoe Falls are cutting back at the average rate of four 

 to five feet each year and no longer have the smooth horseshoe 

 curve at their crest which gave them their name. Until St. 

 Mary's River cuts through the Cambrian sandstone sill at the 

 rapids, Lake Superior will be held in its basin twenty feet above 

 Lake Huron. But when these rock barriers have been cut away, 

 the lakes will shrink in their basins and once again will become 

 a great river system. Then the records of these lakes also will 

 be shown by the beaches and shores they have made. 



For a long time the land has been fairly stable; but occa- 

 sional slight earthquakes, the deepening of the waters on the 

 southern shores of the lakes, the withdrawal of water from the 

 northern shores — exposing the lake bottoms, and other evi- 

 dences, all show that uphf t has not ceased. Measurements indi- 

 cate that the North American continent is rising at the rate of 

 about one inch every ten years for each 100 miles north of the 

 Whittlesey hinge line. Will it rise high enough to spill the 

 lakes over the limestone sill at Chicago, which is only eight 

 feet above Lake Michigan, and return the flow to the Gulf of 

 Mexico ? Has the glacial period passed or are we in an inter- 

 glacial stage? Will the ice return and destroy all the evidences 

 by which this story is told? If this happens it will be so far in 

 the future — so many thousand of years — that another civili- 

 zation will write the story. 



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