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NEW YORK STATE MUSEUM 



second; for September, 5.83 cubic feet per second; for October. 

 5.8 cubic feet per second. Expressed in cubic feet per second per 

 square mile, the foregoing results are 0.218 cubic foot for August, 

 0.212 cubic foot for September, and 0.211 cubic foot for October. 

 Expressed in inches on 'the catchment, the runoff of this stream 

 for August to October, 1891, was from 0.24 to 0.25 inch per month. 

 For several days during the months of August to October, 1891, 

 the flow of Oatka creek was down to about 4.2 cubic feet per sec- 

 ond, or to about 0.151 cubic foot per second per square mile. On 

 September 26, 1891, the recorded mean flow for the day was 3.77 

 cubic feet per second, or 0.137 cubic foot per second per square 

 mile. 



As a general proposition, statements of minimum flows of 

 streams ought not to be based on the records of single days, 

 specially on streams where there are mill ponds above the point 

 of measurement, because such accidental circumstances as the 

 holding back of the water may vitiate the result; from this point 

 of view an average extending over as long a period as possible 

 should be taken. 



The measurements of Oatka creek from August to October, 1891,. 

 illustrate well the nearly universal tendency of streams to run 

 either at approximately a. fixed rate or to decrease only very 

 slowly after the tributary ground water has become well drawn 

 down. For several days at a time the records show only slight 

 variation. 



Minimum flow of Morris run. The result of a measurement of 

 Morris run, a tributary of Oatka creek, the source of a part of the 

 water supply of the village of Warsaw, Wyoming county, made 

 from July 4 to December 26, 1894, is shown by table No. 82. The 

 measured catchment area is 156 acres, but it may, by reason of the 

 peculiar topography be somewhat greater than this. The water 

 issues along the thread of the short valley in the form of springs; 

 The measurement was made by a thin-edged notched weir at a 

 point just below the lowest spring. As may be observed, the flow 

 varied greatly at different times, the minimum being 77,(;:>< ) gal- 

 lons per day or 7.2 cubic feet per minute, in October. On July 8 

 the discharge was 238,580 gallons, or 22.1 cubic feet per minute 

 for twenty-four hours. There is a popular impression that 

 springs do not vary their flow at different seasons. The measure- 



