610 eeport of commissioner of fish and fisheries. 



8. — steck's fish-way. 



The invention of Daniel Steck, (Plate XXII, fig. 2,) of Pennsylvania, 

 differs from Smith's in having the partitiou-walls placed very near to- 

 gether, giving long "and narrow pools running across the fish- way, and 

 in having the iloor of each pool slope upward from the entrance to the 

 outlet. The advantages of this plan are, first, that it enables the builder 

 to accomplish the descent in a much shorter distance, thus bringing the 

 foot of the fish-way nearer the dam ; and, secondly, that it avoids eddiesr 

 the pools being too narrow to permit them. The disadvantages are that 

 it requires the occupancy of a great breadth of the dam, and that, when 

 the supply of water is scanty, the fall at each step will be an impedi- 

 ment to fish. 



9. — INCLINED-PLANE FISH-WAYS. 



The fundamental distinction of these from the step-fish-ways is that 

 the descent is accomplished by a general inclination of the floor instead 

 of steps. The fish-ways of this class requiring notice are the Pennsyl- 

 vania style, the common rectangular, Brackett's, Foster's, and Swazey's. 

 All excei)t the first named are built with compartments to check the 

 velocity of the current. 



10. — THE PENNSYLVANIA FISH-WAYS. 



These are two structures built by the State of Pennsylvania in the 

 dam at Columbia on the Susquehanna River. They are both perfectly 

 plain open sluices, entirely beyond precedent in dimensions and ease of 

 grade, and distinguished from all the common styles by being located 

 in and above the dam, instead of projecting in front of it, so that to the 

 ascending fish the entrance to the fish-way appears as a simple gap in 

 the dam. 



The first (Plate XX, fig. 3, plan in outline; fig. 4, profile in same) 

 -was built in ISGG, at a point 1,500 feet from the right bank of the 

 river; the total length of the dam being G,SOO feet, and the height of 

 the fall about C feet. The fish-way is 45 feet long, 20 feet wide at the 

 upper end, and 40 feet wide at the lower end. The widening of the floor 

 is effected by offsets, with the design of affording resting-places for fish.; 

 (this feature was omitted from the later plan.) The grade is 1 in 15. 

 The outlet is on aline with the face of the dam. Both fish-wa}^ and dam 

 are of heavy crib-work, filled with stone and furnace cinder. 



Uncertainty existing as to the success of this structure, a still larger 

 one (Plate XX, fig. 1, plan in outline; fig. 2, profile in same) was built 

 in 1873, at a point 2,500 feet from the left bank, where it was thought 

 that shad congregated when stopped by the dam. The new fish-way 

 is of a uniform width of CO feet, is 120 feet long, and has a grade of 1 

 in 35. Colonel James ^Yorral, the engineer who designed both fish- 

 ways, estimates the velocity of the current in this one to be less than 10 

 miles per hour. 



