THE 



AMERICAN JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



Art. XLIY. — Another Episode in the History of Niagara 

 Falls; by J. W. Spencer. 



[Read before American Association for the Advancement of Science, August, 189S.] 



Contents : 



Summary of the Changing Physics of the River. 



Revision of the Episodes of Niagara River. 



The Newly-discovered Episode — the Niagara Strand. 



The Modern Episode. 



The Rise of the Ontario Waters. 



Explanation of the Narrows of the Gorge at the Whirlpool Rapids. 



Summary of the Changing Physics of the River. 



Four years ago, a paper was presented by the writer to the 

 American Association for the Advancement of Science,* com- 

 puting, for the first time, the age of the Falls, as based upon 

 the changing episodes of the river. The data upon which the 

 computations were made embraced not only the measurement 

 of the modern rate of the recession of the Falls, but also the 

 discoveries : (1) that the Niagara River did not formerly drain 

 the Algonquin (Superior-Michigan-Huron) basin (which then 

 emptied towards the northeast)*)* ; (2) that the river for a long 



* "Duration of Niagara Falls," by J. W. Spencer, this Journal, vol. xlviii, pp. 

 455-4T2, 1894. 



f Mr. F. B. Taylor has stated that the "original hypothesis " of " a northern 

 way of discharge of the upper lakes " was first suggested by Mr. G. K. Gilbert 

 in 1886 (Bull. Geol. Soc. Am., vol. ix, p. 80, 1898). But it is manifest that Mr. 

 Taylor is laboring under a misapprehension. The discovery of the evidence and 

 the announcement of the hypothesis that the drainage of the uppermost three 

 lakes was diverted from the Niagara River, by the discharge of their waters 

 towards the northeast, was first communicated by the present writer to the meet- 



Am. Jour. Sci. —Fourth Series, Yol. VI, No. 36. — December, 1898. 

 31 



