Niagara Falls 



End of the Falls 



1895 As has already been noted, the falls were in danger of being 



Spencer ended by the turning of the waters into the Mississippi, when the 



cut through the Johnson ridge was effected. With the present 

 rate of calculated terrestrial uplift in the Niagara district, and 

 the rate of recession of the falls continued, or even doubled, 

 before the cataract shall have reached the Devonian escarpment 

 at Buffalo, that limestone barrier shall have been raised so high 

 as to turn the waters of the upper lakes into the Mississippi drain- 

 age by way of Chicago. An elevation of 60 feet at the outlet 

 of Lake Erie would bring the rocky floor of the channel as high 

 as the Chicago divide, and an elevation of 70 feet would com- 

 pletely divert the drainage. This would require 5,000 or 6,000 

 years at the estimated rate of terrestrial elevation. It would be 

 a repetition of the phenomena of the turning of the drainage of 

 the upper lakes from the Ottawa valley into the Erie basin. 



Concl 



usions 



The computation of the age of the Niagara river, — based 

 upon the measured rate of recession during 48 years; upon the 

 changing descent of the river from 200 to 420 feet and back to 

 320 feet; and upon the variable discharge of water from that 

 of the Erie basin only, during three-fourths of the life of the 

 river, to afterwards that of all the upper lakes, — leads to the 

 conclusion that the Niagara Falls are 3 1 ,000 years old and the 

 river of 32,000 years duration; also that the Huron drainage 

 turned from the Ottawa river into Lake Erie less than 8,000 

 years ago. Lastly, if the rate of terrestrial deformation continues 

 as it appears to have done, then in about 5,000 years the life of 

 Niagara Falls will cease, by the turning of the waters into the 

 Mississippi. These computations are confirmed by the rate and 

 amount of differential elevation recorded in the deserted beaches. 

 It is further roughly estimated that the lake epoch commenced 

 50,000 or 60,000 years ago, and there was open water long 



600 



