42 Report of the American 



dulity and hesitate even to prononnce beforehand in favor of the new 

 one until shad shall absolutelj' be taken in nets placed at its head. 



Herewith is submitted a diagram of both the chutes, in plan and in 

 profile, in order that a correct idea may be formed as to their form and 

 their inclinations. 



[It is impossible to give these diagrams as they would occupy too 

 much space.] 



In December, 1873, the Penns^'lvania Commissioners, Messrs. Reeder, 

 Hewit and Duffy, visited both the chutes when the water as it entered 

 them was about four feet in depth, the stage at which the shad are 

 usually running in the spring. At this stage the chutes can only be 

 approached in a steamer. The inclination of the new chute appeared so 

 gentle that it was the unanimous opinion of all on board the vessel, that 

 if shad could not ascend that comparatively gentle current the}- would 

 ascend no artificial incline that can be made for them. I have not the 

 slightest doubt that shad can and will ascend it. Bat the old chute was 

 also visited, in which they did not express the same confidence. For in the 

 first place, the area of the earl}' chute is not one-fourth that of the second, 

 whilst the inclination of the first is as 1.15 is to 1.35. Certainly the 

 latter structure is much the more eas}" of ascent. But the effect of the 

 two chutes in the water below was very similar. A long stream begin- 

 ning in white caps and undulating in diminished graduation, was 

 observed below each of them in the line of the axis of the chute, produced 

 and plaml}^ preceptible for about two hundred yards below the steeper 

 chute and about one hundred and fifty yards below the gentler one. It may 

 be mentioned here as a memorandum that the river below the dam, even 

 in high waiter, is not deep. At low water the dam stands on a bottom 

 scarcely averaging a foot in depth. And the fishways both fall into 

 water at that stage not more than three feet deep, and when the shad 

 are running the water below the dam scarceh' averages four feet. 



It is well known that shad are always attracted from their ver}^ earliest 

 infancy by an opposing current ; and that they are equally attracted by 

 both these currents below the dam can scarcely admit of a doubt. So 

 attracted, in the one case 200 yards below the dam and in the other 150 

 yards below it, they would undoubtedly stem both currents without prefer- 

 ring one to the other. For how could they know what there was to overcome 

 at the head ? Admitting the fact of the shad entering the currents at all 

 the question left to be decided is : Can they overcome the velocity of 

 the chutes. There is no hydraulic rule on the subject of water moving 

 down inclined planes, which will give the water in either of these chutes 

 a greater velocity than ten miles an hour. 



Impeded by friction and by the water below the dam always endeav- 



