52 THE SALMON FISHERIES. 
clear; the chambers in the upper part are mostly about 
11 feet long, while in the lower part they are about 12 feet. 
Thus there is ample room for a salmon to rest, and in 
comparatively quiet water. The stops are 21 inches high 
on the lower side, and 16 inches on the upper. The breaks 
in these stops are 13 inches wide; at about 14 inches or 
15 inches in depth in parts of the compartments. 
The ladder over the Collooney fall is similar in design to 
that just described, though differing somewhat in detail. 
Its entire length is 200 feet, which gives an incline of I in 
12, the rise from water to water being about 163 feet. The 
width is 8 feet 9 inches, and the chambers average 8 feet 6 
inches in length. The stops are 19 inches high, with breaks 
II inches wide. (For sketch of the ladder see Frontispiece.) 
The three upper stops, however, are different from all the 
rest. They were originally 20 inches high, with 9-inch 
breaks ; but the rush of water was found to be too great, 
and a plank 13 inches high was placed on the top of each 
of these stops, extending right across the ladder, but 
leaving the openings as originally made. With one or 
two minor alterations suggested by experience, the ladder 
acts admirably, and the fish, which used to otherwise jump, 
and jump in vain, at the hopeless obstruction, swim up it 
with the greatest ease. 
The cost of these two passes, with a third of less impor- 
tance at the intervening falls, was about £1000, and their 
construction has practically created a salmon fishery worth 
f£ 3000 a year. 
There are hundreds of weirs in the country where a very 
much smaller expenditure in the construction of a pass 
would produce proportionately valuable results. It is not 
every pass that need cost £400 or £500. A dam eight feet 
high can be rendered accessible to salmon at less than half 
