HYDROLOGY OF NEW YORK 



329 



run, working head on wheels, readings of head-race and tail-race 

 gages, and other information necessary for keeping an accurate 

 account of the water passing over the crest in 24 hours, as well 

 as through water wheels for the same period. Gage readers were 

 employed to take these readings twice each day. 



In order to obtain flows through water wheels, recourse was 

 had to records of the test flume of the Holyoke Water Power Com- 

 pany of Holyoke, Mass., where the principal wheels now in com- 

 mon use in New York State have, at one time or another, been 

 tested. On requesting a record of such tests, as applying to 

 wheels at the several gaging stations, the Holyoke Water Power 

 Company responded that they would furnish the records under 

 the condition that they be not published unless the consent of 

 parties for whom the wheels had been tested were first obtained. 

 This condition being assented to, information was furnished as 

 to tests of the principal wheels in use, giving proportional part 

 of opening of speed gate for various conditions of tests, revolu- 

 tions of wheel, quantity of water discharged, power developed, 

 efficiency, etc. From these records, wheel-discharge curves have 

 been prepared for the water wheels in use at each dam. By the 

 use of such curves, derived from actual tests, it is believed that 

 the discharges through turbine water wheels at the various gaging 

 stations have been computed with a very high degree of accuracy. 

 Under these conditions turbine water wheels become in effect 

 efficient water meters. In a few cases, where there were no tests 

 applying, the discharges as per manufacturer s' tables have been 

 used. The writer's thanks are due to the Holyoke Water Power 

 Company for the courtesy of furnishing these useful data. 



The icork of Henry Bazin. In order to apply the results of 

 these gagings, the work of Henry Bazin, Inspecteur General des 

 Ponts et Ghaussees, which may be found in Annates des Ponts et 

 Ghaussees, for the years 1888, 1890, 1891, 1894, 1896 and 1898, is 

 used. In these papers Bazin has determined coefficients for a large 

 number of cases, not only of crests of different widths, but with 

 varying front and rear slopes, as well as for curved profiles. 

 Indeed, taking into account the backward state of knoAvledge of 

 flow over weirs, his work is in many respects revolutionary. 



