596 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



(lam and tbe tendency of the current lead the fish directly to the fish- 

 way. 



It is sometimes the case that the approach to the dam from below is 

 obstructed by a natural fall of sufficient difficulty to seriously impede the 

 ascent of fish. Under these circumstances it is often admissible to place 

 the mouth of thefish-waj^ at a distance from the dam, which, under ordi- 

 nary circumstances, would prove fatal to its success. Departure from 

 the general rule is, however, to be taken only with extreme caution ; 

 since an error in this respect is often irremediable. 



When from any cause it is impracticable to place the mouth of the 

 fish-way in close proximity to the dam, it is sometimes practicable to turn 

 the fish into it by a hurdle or other artificial obstruction placed across 

 the stream. It would be better to place the hurdle obliquely; the mouth 

 of the fish-way being at its upper end. Extensive contrivances of this 

 sort cannot be maintained in our larger rivers, nor in those smaller ones 

 where timber-refuse and other rubbish abound. A hurdle extending a 

 short distance into the stream is frequently serviceable. One has been* 

 devised to turn shad into the fish-way at Holyoke, on the Connecticut, 



2. — ATTRACTIVENESS. 



The second essential requisite in a fish-way is attraciivencss. Fish 

 must be invited to enter, and the only known means of extending such 



* The following extract from a letter of Mr. J. W. Milner throws additional light ou 

 this subject. Speaking (from personal observation) of the Holyoke fish-way. he says : 

 " The reverted portion of the fish-way faces the dam at the point where the sheet of 

 water coming over the crest is the deepest, and where, of course, the most ample vol- 

 ume of wiiter flows. At a high stage of water in the river, the cribs at the moutli of 

 the fish-way are entirely submerged, and the outflow is directly into the face of the 

 strong counter-current coming from the dam. The channel-way on this side nest the 

 fish-way is quite clear of rocks, aud a free, ample volume of water flows unob- 

 structed by the end of the fish-way, aud, deflected by the wing-dam, turns outward un- 

 til it has passed it. Outside of tbe channel-way are numerous large rocks aud broken* 

 foaming wa*^er. The shad seek the open channel-way in their passage up stream, aud 

 are led, iu following it, close by the mouth of the fish-way ; but, feeling the stroug, fresh 

 force of the current from the dam, they strike boldly iuto it, uot iu the least tempted 

 by the weak current from the fish-way. Standing on the cribs above, I saw this hap- 

 pen day after day. Frequently as many as twenty shad in a school would pass up 

 toward the dam, and they always quickeued their movement as they felt the fresh flow 

 of the water coming. 



"There were two methods which I thought of for inducing the shad to enter: one 

 was to continue the fish-way along the wing-dam, instead of turning it up stream, aud 

 then, by means of a low wing-dam iilaced a short distance above the mouth, turn a 

 portion of the stroug current iuto the cribs of the fish-way. For a short distance it would 

 be well to take out the bulkheads, so as to make a guide-way to the beginning of the 

 winding current of the ladder. The other method was, to open the side of the crib 

 next to the wing-dam, and make the outlet iu the upper compartmeut of the reverted 

 liortiou. Heavy iron rods should theu be set in the rock-bed of the river in the proper 

 order, and. a heavy netting stretched upon them, in the form of one side of the ' heart' 

 of a pouiid-net, in this way utilizing a principle which the fishermen make so eftective 

 in esterm iiatiug the fish iu aiding them to perpetuate their race and species." 



