792 



NEW YORK STATE MUSEUM 



considerable areas from which, due to a luxuriant vegetation, the 

 summer evaporation may be as much as 60 inches over the actual 

 ground area affected. The land -damage on these areas will be 

 considerable and should be taken into account in the estimate. 

 In dry years, with a total rainfall from June to November inclu- 

 sive of from 8 to 12 inches, the amount required to keep up this 

 great evaporation must come by percolation from a deep water- 

 way channel. If we assume an area of 10 square miles as affected, 

 the amount of water required to keep up constant evaporation on 

 the basis of 60 inches for the navigation season would be nearly 

 80 cubic feet per second, or, even if we consider the area affected 

 as not exceeding 5 square miles and take into account the loss into 

 the old-water channels, it seems rational to allow percolation from 

 summit level of 75 to 100 cubic feet per second. 



Leakage at gates and structures is a very uncertain element. 

 Under ordinary conditions the gates ought to be worked without 

 very much leakage. The data furnished indicate a probable loss 

 from this source of perhaps 60 to 80 cubic feet per second. 



A considerable amount of power will be required at each lock 

 for operating gates and for electric light at night. A conserva- 

 tive allowance for this purpose seems to be from 20 to 25 cubic 

 feet per second at each end of summit level, or a total of 40 to 50 

 cubic feet per second. 



On the Erie canal considerable time is saved by flushing boats 

 out of the locks on to the lower levels by letting water through the 

 gates from above. The writer does not understand, however, that 

 this practice is specially applicable to locks passing boats carry- 

 ing their own power. In order to accommodate local traffic it is 

 probable, even though deep waterways should be constructed on 

 substantially the line under consideration, that the Erie canal 

 would be maintained on its present line from near Rome to Buf- 

 falo. Independent of other considerations, this would lead to con- 

 siderable traffic on deep waterways in the way of barges, timber 

 rafts and fleets of canal boats, the handling of which will probably 

 be more or less expedited by a reasonable use of water for flushing 

 out on to the lower levels. As a matter of judgment purely, this 

 item has been placed at from 50 to 60 cubic feet per second, al- 

 though by the use of mechanical arrangements for doing this work 

 the quantity of water could be materially reduced, flushing being 

 in any case an uneconomical method of applying power. 



In order to pass the large Hood Hows of the tipper Mohawk with- 

 out great fluctuation of the water surface, it will l>e necessary to 

 provide from 2000 io 2500 linear feet of spillway at each end of 

 the summit level, and over which, whenever there is any interrup- 



