Report U. S. F. C. 1898. (To faco page XXX.) 



Plate 



Section #-B. 





Sec//'on CrD. 





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e ^MixQii/^i^-ir'i-tf jc e 



Hv.B. ial. 



DUtECTIONB. 



Slopoof lishway should not bo steeper than mi a ratio of l vertical in 4 horizontal. 

 Intake, or up-stream end of tirfli \va\ , should be amply lar^o and placed not 1 

 Br than crest of dam. 



Outlet should be below low-water level ami so located or onutrnetod that lisb are 

 naturally led to it, when nnnanfling the stream. 



. ely deep water, with an unobstructed How below the outlet 

 of the fishwav. Au ample discharge of water should attract the lisb to the outlet. 



Then- should bo plenty of light admitted in the lishway. and its construction should 

 lie sueh as to be readily inspected and cleaned id' any debris lodging therein. 



The floor of the Compartments should be laid slightly Inclined and the bulkheads 



obliquely across the tishway, so that the current of water passing through 



the compartments can more readily char the same of sand, gravel, mnd, and rubbish. 



There should be no regulating gates or other devices at the intake which D< 

 the services of an attendant. 



The apertures in the bulkheads should inorei ly from the lower to the 



upper ones, to Inanreoverflow from compartment to compartment. 



The How of water should be abundant, forming small waterfalls over the bulkheads, 

 so that the lisb may either .jump from one compartment to the next above or may dart 

 through the apertures in the bulkheads. 



While the. How of water through the apertures may reach a velocity of V 

 second, there will be relatively the compartments, thus furnishing a 



resting place for the ascending 



To maintain the operation of the tishway at an average high water the same as at 

 the ordinary Btage of the stream or river, the uppermost, compartment is made some- 

 what longer, iuui a central bulkhead is inserted having its crest at high-water level. 



The lishway may be constructed of wood or masonry and iron; It may follow 

 line or be built in angles and curves, as the b quire. 



of the tishway depends principally on tin- volnmeof water at ailabl 

 be made larger or smaller than that, shown on plan. The hydraulic head bet w sen two 



'o obtain a current velocity through the 

 apertures of not to exceed In feet pec second. At low water Stage of the stream or river, 

 w it lit ho tishway flowing full, there should bealiberaldisohargeovertheorest of the dam. 



The tisbwav should be built very Btiong and be well protected against the destructive 

 effects of freshets, drift ice, etc 



FISHWAV-IMPROVED CAIL SYSTEM. 



