Science, Geology and Physics 



this whole question of the run-off of Niagara River has become 1899 

 fogged by a discussion based thus far purely on averages. What a ,er 

 we really want to know is the run-off of a cycle of dry years. 

 With such data we can compute the effect of a given diversion 

 more satisfactorily than when dealing with means. 



With a cycle of rainfall years, either high or at about the 

 average, it is probable that very little effect from such diversion 

 will be observed, the consensus of opinion at the present time 

 apparently being that it will not exceed about 0.3 to 0.4 foot 

 in depth over the areas affected. Owing to the balancing of 

 conditions due to the immense pondage of the Great Lakes, and 

 which requires years in order to complete a cycle, it fs uncertain 

 whether the abstraction of 10,000 cubic feet per second at 

 Chicago would be especially detrimental at Niagara Falls, 

 although in years of extreme low flow it is probable that it would 

 be easily apparent. If, however, the minimum flow of Niagara 

 River is really as low as 150,000 to 180,000 cubic feet per 

 second, it is clear that the loss of 10,000 cubic feet per second 

 will be a matter worth taking into account. 



Wright, George Frederick. New method of estimating the age 1899 

 of Niagara Falls. (Pop. sci. mo., June, 1899. 55:145-154.) Wright 



The new evidence lies in the extent of the enlargement of the 

 mouth of the Niagara gorge at Lewiston since the recession of 

 the falls began. . . . The estimate of about ten thousand 

 years for the date of that stage of the Glacial period in which 

 Niagara River first began its work of erosion at Lewiston (an esti- 

 mate which is supported by a great variety of facts independent 

 of those relating to Niagara gorge) is strongly confirmed by 

 this new line of evidence. 



1900 



Geology of Niagara. (Sci. Am. sup., March 3, 1900. 49:20208.) 1900 

 This article agrees with Spencer's theory of the origin of Niagara, 

 giving briefly the geological history of the great lakes and Niagara. 



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