68 FISH—CULTURAL ASSOCIATION. 
furnishes the foundation for the structure of the fish-way proper 
which is placed within it. 
Details of construction are given in figures 7, 8 and 9, which 
are on a scale of one-fourth of an inch to the foot. The sub- 
structure having been established, we begin by setting up along 
the centre line of the trough or sluice, the bulkheads /, /, 7, and 
C, at intervals of twelve or fifteen inches. These are made of 
planks one and a half inches thick, two feet long and fifteen 
inches wide. These are firmly attached to the flooring of the 
sluice either by spikes or bolts. Posts H, #' and C, of one and 
a half inch stuff, nine to twelve inches wide, and extending from 
the floor to the upper edge of the inclined trough, are now set up 
at similar intervals of twelve to fifteen inches, and firmly secured 
to the sides and bottom of the trough. To the posts H, H, and 
bulkheads /, /, the fifteen, inch joists are securely) nailed jor 
bolted. The floor D, fig. 8, of one and a half inch plank is next 
laid and nailed to the inclined joists as shown in figures 7 and 
8, upon the floor D. Next set up the short return buckets JZ, 
M, and C, figures 8 and 9, securing the same to the parts 4, Z, 
and to the floor by nailing or other suitable means. The cap 
£, £, fig. 8, made of a single two inch plank is fastened securely 
to the sides 4, B, the posts H, H, and the return buckets J, M 
thus completing the construction. 
We have here realized in timber the same construction and 
secured the same control of the descending current as shown in 
the experimental apparatus, fig. 5. The course of the water is 
shown by the arrows. When a sufficient supply of water is 
_ brought to the head of the fish-way, we will have an average 
depth of water way above the floor, D, of ten to twelve inches. 
Any excess of water over the amount needed to fill the fish-way 
will be shed over the sides, and the fish-way will continue in 
efficient operation in any stage of water. 
In the drawings figures 7, 8 and g, the open spaces between 
the bulkheads /, 7, and C, and also the head of the fish-way 
where the water passes under the floor D, directly from the dam, 
is represented as guarded by a wrought iron grating. This is 
only necessary where the exposed position requires that the 
weak points be protected from injury by ice or drifting timbers 
