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REPORT OF THE COMMISSIONERS OF 



These I imagine to be outside figures subject to considerable modification when 

 existing conditions are actually known and the time of building the fishways can be 

 selected by the builder. 



The improved Cail fishway is one that has not been used in this State and I know 

 little about it except that it has been approved by the Commissioner of Fisheries of 

 the United States, which is all-sufficient to warrant its adoption where a fishway is 

 needed. It has one very marked feature in its favor, and that is cost of construction. 



Upon this point I have received an informal letter from the United States 

 Fisheries Commission as follows : 



The Cail fishway, as modified by Mr. Von Bayer, our engineer, is believed to be a most 

 effective form of fish pass, but we have not had an opportunity of practically constructing any 

 of them; consequently, any information we may give you on this subject will be purely 

 speculative. The construction of a fishway always depends upon the character of the dam 

 in which it is to be constructed. For example, in a well-built crib dam where there are only 

 a few stones to.be removed, etc., Mr. Von Bayer thinks $300 would cover the cost of a wooden 

 fishway in a dam ten feet high. In favorable conditions the cost would increase in proportion 

 to the height, that h, twenty feet high would cost $400 to $500. 



Certainly this form of fishway costs much less than any that I have mentioned, 

 and if upon actual trial it proves to do the work for which it is intended, as well as 

 any other style of fishway, the cost of construction will be greatly in its favor. The 

 illustration of sectional elevation and cross section will show how the fishway is con- 

 structed, except as hereafter explained. It will be seen that instead of arms or buckets 

 the flow of water is moderated by a series of bulkheads. The floor of the compart- 

 ments formed by the bulkheads should be laid slightly inclined and the bulkheads are 

 placed obliquely across the fishway. Each bulkhead has an aperture in alternate ends 

 and they increase progressively from the lower to the upper ones.* 



No regulating device or head gate is required at the intake and light is admitted 

 to the fishway from the top. The hydraulic head between two successive compart- 

 ments must be so chosen as to obtain a current velocity through the aperture of not 

 to exceed ten feet per second. Fish may pass through the aperture or jump the 

 bulkheads as is shown in the drawing: of sectional elevation. 



* Since the illustration of the improved Cail fishway was engraved, for this report, it having been 

 made from plans furnished through the courtesy of Hon. George M. Bowers, United States Fish 

 Commissioner, Mr. Von Bayer, the Engineer and Architect of the Commission, writes me as follows : 

 " Referring to the plans of an Improved Cail Fishway lately sent you, you are advised that the 

 aperture in the uppermost cross bulkhead of the fishway marked on the sectional elevation under the 

 word "Crest" 15'' x 15" should be i8"xi8". This letter was received too late to make the change 

 in the illustration as the impressions for the entire edition of this report had been printed. A. N. C. 



