SPOLIATION OF THE FALLS OF NIAGARA 295 



on previous occasions, although I am aware of a statement by an engineer 

 holding a distinguished position, to the effect that we do not know that 

 the levels are going to recede. This appears to have been said for 

 politic reasons, as the pressure to further divert the water is very 

 strong. 



There is much popular curiosity as to the cause of the high water, 

 which is not wholly explained by the rainfall. Mr. E. S. Wheeler, of 

 the U. S. Lake Survey, found in his elaborate study of the physics of 

 the rivers that changes could be produced by ice jams holding back 

 the discharge and raising the lake so high that upon the melting of 

 the snows together with spring rains, the waters could not run out 

 sufficiently fast during the ensuing season, so as to bring the levels of 

 the lakes to their normal condition. These effects could accumulate 

 during succeeding seasons so that the extraordinary stages might last 

 not merely one year, but for several years. 



From the foregoing, it must be apparent to any one that no opinions 

 can be formed on power diversion which ignore the fluctuations of lake 

 levels, for as these vary, so do the discharges of the rivers. The mean 

 discharge of the Niagara Eiver for 1901, a year of very low water, was 

 14,000 cubic feet per second below that of the mean level from 1891 

 to 1905. This was after the abstraction of a certain quantity of water, 

 the exact amount of which is unknown to me, but probably not reaching 

 10,000 cubic feet per second. The mean discharge during 1907 reached 

 15,000 cubic feet per second above the average of the fifteen years 

 mentioned; this being after the artificial abstraction of nearly 18,000 

 cubic feet per second. Thus the entire diversion of the Niagara 

 waters has been not only concealed by the extraordinary stages of 

 the river, but a further quantity could be withdrawn without any 

 apparent effect upon the falls. The increasing discharge of Lake 

 Erie, during this year, reached the maximum on April 27, when it 

 rose to 60,000 cubic feet per second above the average of the fifteen 

 years mentioned, besides which the diversion was probably nearly 

 18,000 cubic feet ; so that the full use of the franchises of the present 

 power companies would not impair Niagara Falls to-day, but this 

 condition can not last, and it is unfortunate that it should occur at 

 this time, for the sake of those who are interested in the preservation 

 of the falls, as well as in the navigation of the lakes. 



In studying the physics of Niagara Eiver, individual months or 

 single years can not be adopted as standards, but I have found that 

 satisfactory results can be obtained by taking groups of five-year 

 periods. Perhaps some other arrangement might prove better. This 

 has resulted in my adopting as standards of lake levels and river 

 discharges, the means of the fifteen years succeeding the lowering 

 of the lake outlets, and the present temporary high water will doubtless 



