twfl 



228 



REPORT OF THE COMMISSIONERS OF 



based upon its width, and for small fishways of this kind the inventor, the late Colonel 

 Marshall McDonald, formerly Commissioner of Fisheries of the United States, 

 furnished this table : 



Width, 



1 2 inches, 



slope, . 



1 



foot in 2, 



. 18 



u 



1 



" 3, 



. 24 



a 



1 



" 4, 



• 3° " 



11 



1 



" 5, 



• 36 " 



.i 



1 



6. 



The original McDonald fishway was entirely different in principle from any of the 

 others named, and in its modified form uses iron buckets as shown in the illustration 

 of a section of a twenty-four-inch fishway. The Rogers fishway may be constructed 

 in several different ways, but the one shown in the half-tones of the Binghamton 

 fishway, of which there is also a plan of construction on another page, is perhaps the 

 best form for ordinary dams, as the entrance is at the base of the dam and the incline 

 leads down stream to a pool inside the enclosed structure, and then turns up stream, 

 over and a little at one side of the lower passage, and the fish find exit over and above 

 the dam. The slope in this form of fishway is arranged to meet the necessary 

 requirement in the case of each particular dam under consideration. 



The power of fishes to surmount obstructions in a stream such as falls or dams, is 

 very limited except in the case of members of the salmon family. 



The salmon (salar, its specific name, from salio, to leap) is a born jumper, and with 

 a deep pool to start from at the base of a waterfall, will, when ascending a river to 

 spawn, jump over obstacles that seem impassable for any fish. Dr. Landmark, 

 Inspector of Fisheries of Norway, conducted some experiments for the Norwegian 

 Government to test the power of the salmon in this respect, and when extracts from 

 his report were translated and printed in English, they gave rise to considerable dis- 

 cussion on the subject in this country. Dr. Landmark wrote me as follows in 1894: 



Concerning the height that salmon can jump under favorable circumstances, there is one 

 place in Norway with indisputable evidence that there salmon have sometimes made a perfectly 

 clear jump of sixteen feet perpendicular height. * * * No doubt a jump of the said height 

 is quite unusual ; but, having myself examined the spot where the occurrence has taken place, 

 and having heard the evidence of persons who have themselves witnessed it, 1 cannot doubt 

 the fact. 



Since Landmark's experiments, Dr. Robert T. Morris, of New York city has seen 

 salmon in the act of jumping over falls on rivers in Labrador that were from twelve to 

 eighteen feet high and has photographed the fish, a half dozen of the pictures being 

 before me, in the air as they made the leap and has measured the falls at the point 

 where the jump was made. 



