HVDR0L0GY OF NEW YORK 



403 



A comparison of the gagings at Warrensburg with those of the 

 Hudson river at Mechanicville indicates that the runoff of Schroon 

 river is considerably greater than that of the Hudson, the differ- 

 ence occurring mostly in the storage period. This is probably 

 true, although some uncertainty attaches to the gagings at War- 

 rensburg, owing to an increase in the leakage from year to year. 

 The writer visited Warrensburg in October, 1895. At that time 

 the pulp mill was not running, and due to the fact that Starbuck- 

 ville dam was closed tightly very little water was running in 

 Schroon river. The water in the Warrensburg dam stood about 

 4 feet below the crest. The bed of Schroon river below the dam 

 was very nearly dry. the flow not exceeding one to two cubic 

 feet per second. The writer has not seen this dam in several 

 years, but reports indicate that the leakage may be anywhere 

 from 30 to 50 cubic feet per second. 



When the flashboards are on, the computations have been cal- 

 culated by means of Francis' formula for sharp-crested weir. 

 Without the flashboards, the quantities are taken from a diagram 

 deduced from the Cornell University experiments. In 1902 this 

 mill was rebuilt. 



Geologically the headwaters of this stream lie in the horizon 

 of the Plutonic norites and flow across the unclassified granites 

 and gneisses. 



Discharge measurements of Mohawk river at Dunsbach Ferry. 

 Mohawk river has been an important avenue of commerce ever 

 since the early settlement of the country. Nevertheless very 

 little was known as to the water yield until the investigations of 

 the Board of Engineers on Deep Waterways in 1898-9. The 

 writer established for this Board gaging stations at Kidge Mills, 

 Little Falls and Rexford Flats. The station at Dunsbach Ferry 

 was established in March, 1898, by D. J. Howell. At present 

 gagings over dams are kept at Dunsbach Ferry and Little Falls, 

 while gagings by current meter are made at Schenectadv and 

 Utica. 



The Dunsbach Ferry record is kept at the dam of the West Troy 

 Water Company, just above Dunsbach Ferry bridge, nine miles 

 from the mouth of the river. This dam is in two sections, on 



