Niagara Falls 



1898 To make it a measurement of the absolute rise would be to add 

 Spencer or subtract the changes of the earth's crust at Chicago, which are 



not known. But the rate of rise north of the Adirondack dis- 

 trict was three times as great, and so on for other regions. With 

 this mean rate of rise discovered as in progress for the last 1 500 

 years, it becomes no bold prediction to apply it to the diversion 

 of the Niagara drainage to the Mississippi and the consequent 

 extinction of the Falls. This hypothesis was first announced in 

 March, 1 894, or three and a half years before it was confirmed 

 by Mr. Gilbert's estimates of the fluctuations of the lakes. The 

 results of the latter methods almost exactly confirm the earlier 

 geological discoveries of a rise of the earth's crust, and the conse- 

 quent confirmation of the hypothesis of the extinction of Niagara, 

 at about the same date, when the calculations are reduced to the 

 same basis. 



The history of the Falls is so intimately connected with that 

 of the lakes, and in their archives we find that there have been 

 several changes in the height of the Falls as well as great varia- 

 tions in the amount of water that passed over them during the 

 different episodes. All of these studies are gradually leading us 

 to more and more nearly approach the correct determination of 

 the age of the Falls. [Preface.] 



But the great impetus towards the investigation of the great 

 lakes is due to Prof. J. S. Newberry, whose contribution was 

 followed by one from Prof. E. W. Claypole. To give a full 

 account of the researches concerning the great lakes, and to tell 

 how each author had contributed to the subject would make a 

 very long chapter. As the present writer has been so closely 

 connected with the pioneering study of the subject, and has 

 announced progress from time to time before the American Asso- 

 ciation, it seems a fitting opportunity to tell how his investiga- 

 tions have been influenced by his co-workers, leaving to others 

 the narration of the most recent studies. 



Newberry followed up on the lines of Ramsay in attributing 



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