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NEW YORK STATE MUSEUM 



of the writer is, therefore, that such diagrams are at the best 

 crude approximations. Such study is, however, very fascinating, 

 and it is not surprising that different hydrologists have attempted 

 at various times its solution. Two lines of work may be men- 

 tioned. One is, by a combination of a large number of streams 

 and their rainfall, to attempt to produce a universal formula. 

 This, however, as has been already shown, leads to what is, in 

 effect, a hodgepodge. Averages so applied " bring out class like- 

 nesses, to the exclusion of individual features." 



The other method is to plat rainfall and runoff appearing 

 monthly in inches, as abscissas and ordinates, respectively, and 

 in this way to preserve the individual peculiarities of each stream. 

 In some respects the most satisfactory way is to plat the rainfall 

 and runoff of the storage, growing, and 'replenishing periods, 

 thus grouping similar characteristics. 



Storage in lakes. The runoff of a stream is very materially 

 influenced by the number of lakes within its catchment area. If 

 there are many, flood flows may be expected to be much smaller 

 than they otherwise would be. Oswego river, as a marked stream 

 with large lake pondage, may be discussed in this connection. 

 The total catchment area of this stream is 5002 square miles. It 

 issues from a region with a mean annual rainfall of from 30 to 

 40 inches and with heavy snowfalls, frequently melting suddenly 

 at the end of winter. Nevertheless, the ordinary flood-flows do 

 not exceed 4 cubic feet per second per square mile, and even 

 extreme flood flows are only 6 to 7 cubic feet per second per 

 square mile. As to why this is so is an interesting question 

 which may be answered by considering the large temporary 

 storage on the surfaces of the lakes, marshes and flat valleys in 

 the Oswego area. In order to show this, the writer has prepared 

 the following tabulations, in which appear the names of the sev- 

 eral lakes, with their approximate catchment areas, areas of 

 water surface, areas of flats and marsh, and total area of water 

 surface, flats and marsh. 



