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NEW YORK STATE MUSEUM 



From the date of establishing the station at Dolgeville in 1898 

 to June 1, 1899, the discharge was computed from a curve derived 

 from Cornell University experiment No. 13. From June, 1899, 

 it has been computed from a revised curve, based on experiments 

 by John K. Freeman on a model of the round-crested portion of 

 the Croton dam, which corresponds with the section of the Dolge- 

 ville dam as regards friction, vertical contraction, siphonage, etc. 

 The flow through the turbines has also been computed since 

 June, 1S99, from current-meter measurements in the tailrace, 

 instead of the manufacturers' rating tables, as formerly. The 

 effect of the changes has been to slightly increase the extremes 

 of flow — both as regards high and low water — the flow for the 

 mean stage remaining substantially the same. This dam is prac- 

 tically watertight and no allowance is made for leakage. 



The headwaters of this stream lie in the horizon of the granites 

 and gneisses. It crosses the Trenton group and the Hudson river 

 shales. 



Discharge measurements of West Canada creek. Measurements 

 of West Canada creek have been made at Middleville at the timber 

 dam of the Nelson Knitting Company, which supplies power to 

 four mills. Aside from an ice slide, the crest of this dam is nearly 

 level. The leakage of the dam is taken at 50 cubic feet per second, 

 although the leakage is stated to have increased so much during 

 1901 as to lead to the abandonment of the station. The following 

 cut shows cross-sections and profile of this dam : 



Ki<<. 82 Cross-sections and profile of dam on West Canada creek at 

 Middleville. 



