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NEW YORK STATE MUSEUM 



feet per second, equal to 1.75 cubic feet per second per mile. 

 This section of the original Erie canal was considered to be en- 

 tirely free from leakage at the structures, and the measured 

 losses are therefore taken as those due only to percolation, ab- 

 sorption and evaporation. 1 



In August, 1830, Henry Tracy and S. Talcott, acting under in- 

 structions from W. H. Talcott, Resident Engineer of the Fourth 

 Division of the Genesee valley canal, made a series of observa- 

 tions along the line of Chenango canal, with a view of determin- 

 ing the evaporation, filtration and leakage at the mechanical 

 structures, and whatever else might be useful in the designing 

 of the water supply of the summit level of the Genesee valley 

 canal. 



For the purposes of the measurements they selected a portion 

 of the canal extending from the north end of the summit level 

 to Erie canal, 22 miles in length, on which the total supply on 

 August 31 was found to be 39 cubic feet per second. The leak- 

 age and waste at aqueducts, waste-weirs, and at lock No. 1 at the 

 northern end were found to be 15 cubic feet per second, thus 

 leaving the evaporation and filtration on 22 miles at 24 cubic 

 feet per second, equivalent to 1.09 cubic feet per second per mile. 

 It may be observed, however, that a measurement made at the 

 end of August would probably not show a maximum of either 

 evaporation or absorption by vegetation. Estimating these ele- 

 ments at the maximum, we may assume from 1.33 to 1.67 cubic 

 feet per second per mile as a more reliable quantity than the 

 1.09 cubic feet per second per mile here actually observed. 



Messrs Tracy and Talcott also measured the leakage and 

 waste at the various mechanical structures, etc. which were as 

 follows: Leakage at structures, 3.67 cubic feet per second; waste 

 at waste-weirs, 3.40 cubic feet per second; leakage at lock No. 1, 

 at the north end of the section, 7.98 cubic feet per second. This 

 amount, Mr Talcott remarks, was so much greater than at any 



'See report of F. C. Mills in relation to the Genesee Valley canal (1840). 

 Ass. Doe. No. 26, p. 26. See also report of W. II. Talcott in the same docu- 

 ment. These two reports contain a summary of all that had been done 

 in the way of measurements of the various losses now under discussion up 

 to that time, as well as a number of references to foreign data. 



