40 



to the liundred following' the ii)Wc'st part of the channel, 

 would require a rock cutting fifteen liundred feet long, with 

 a depth of twenty feet in tlie middle, which would be greatly 

 increased by any lateral deviation in consequence of the 

 higher ledges on each side. Besides the whole of the blast- 

 ing and removal of the rock would have to be carried on in 

 the face of the torrent, unless the dam of the Water Works 

 should be extended to tlic Virginia shore, and all the v.ater 

 be allowed to escape by way of Little River. 



From what I have read in the report of the United States 

 Fish Cbmraission, which you Avere kind enough to send me, 

 I am inclined to believe, that if a considerable volume of 

 water were made to issue obliqnely into the main cliannel, at 

 a point lower down the river, and at a velocity, although not 

 great enough to prevent the ascent of shad, yet^ much exceed- 

 ing that of the larger quantity in the main channel ; that 

 most of the fish would be attracted by the superior current, 

 and be induced to follow the artificial watei'-way, and if a 

 barrier were thrown across the main channel, just above the 

 confluence, then all of them would take that course. 



I think that such a fish-way can be constructed at a very 

 moderate expense, by ibllowing the route of Little River and. 

 what is apparently, a continuation of tlio same cleft in the 

 ledo;e below the great transverse cleft. 



I have estimated the cost of such a way, sup|)0sing a grade 

 descending at the rate of four in one hundred to be adopted. 

 Although .such a descent would firodiice a velocity far too 

 rapid if the channel had straight and smooth sides, and bot- 

 tom with much depth of flow: yet, if the water had to strug- 

 gle through and over ragged })rojections of r(X;k, or fragments 

 too heavy to be moved, it would he so imjieded that it would 

 not obtain a general velocity that could not be easily over- 

 tcome by the fish; while everywhere they would find either a 

 resting place or a solid point against Vvdiich to react in their 

 endeavors to stem or mount the current. I have frc([uently 

 ■observed in long stretches of mountain streams descending 

 nearly uniformly at. at least, as great an inclination as this, 

 that the >Spcckled Trout had no difficulty in nmunting, and 

 that I could easily keep up with floating particles, without 

 exceeding a trot on a pathless ground. 



An excavation beginning and ending within a distance of 

 seven hundred feet, and of a deptii in the middle of about ten^ 

 feet, containing less than five thousand cubic yards of rock, 

 ^vill establish the grade of four in one hundred as a maximum 

 in the bed of Little River, and give it a Minimum width of 

 thirty feet. This will coincide; with the present bottom of 

 the transverse fissure to be crossed obliquely, and which would 

 then only require the rock from the excavation to be ])laced 



