HYDROLOGY OF NEW YORK 



317 



Falls, although in years of extreme low flow it is probable that it 

 would be 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. 



In a paper on The Keservoir System of the Great Lakes of 

 the St Lawrence Basin, 1 Col. Hiram M. Chittenden discusses 

 many of The questions in regard to the runoff of the Great Lakes. 

 This paper is accompanied by a Mathematical Analysis of the 

 Influence of Reservoirs Upon Stream Flow, by -las. A. Seddom 

 which elucidates many of the more pertinent facts affecting such 

 flow. 



In the discussion of The effect of diverting 10.000 cubic feet 

 per second at Chicago on the levels of the Great Lakes, by Lyman 

 E. Cooley. which appears in the Proceedings of the Annual Conven- 

 tion of the International Deep Waterways Association, held at 

 Cleveland in September. 1895. it is stated that assuming the cor- 

 rectness of the figures derived from the Lake Survey placing the 

 mean discharge of St Clair river at 225,000 cubic feet per second, 

 the abstraction of 10,000 cubic feet per second would diminish 

 the mean outflow in St Clair river by nearly 1.5 per cent and in 

 Niagara river by about 3.75 per cent. Mr. Cooley says that, 

 reasoning on lines obvious to those unacquainted with hydraulic 

 principles, it is apparent that the ruling depth in the rivers at 

 mean level can not be lessened by an amount greater than the 

 percentages just stated; but if we consider the question as an 

 hydraulic proposition, taking into account the relation of mean 

 radius to area and perimeter, it is apparent that the effect on 

 lake levels would be only a fraction of that indicated by the 

 reduction in volume. 



From September, 1897. to September, 1898, the Board of Engi- 

 neers on Deep Waterways made an extended series of current 

 meter measurements of the outflow of Niagara river. These 

 measurements were made at the International railway bridge at 

 Buffalo, and are the best thus far made. The minimum flow 

 occurred in November. 1895. when the mean for the month was 

 177,852 cubic feet per second, and the mean for the whole year 



lTrans. Am. Soc. C. E., Vol. XL (Dec. 1898), pp. 355-448. inclusive. 



