Srairs ror tue First Fanicirs. ALT 
This pass 1s built into the dam, and constructed of heavy 
timbers fiiled in with stone, or all of solid masonry. It is in- 
tended to be strong enough to resist and break up the acres 
of thick ice, and to prevent the huge trees swept down the 
stream by the spring freshets from injuring any material part 
of the structure, which is so strongly erected, and of such 
heavy material, and imbedded so firmly, as to strengthen the 
dam of which it forms so important a part. 
Fig. 6 is the ground plan, and 7 the side elevation, with 
dotted line showing the bed of the pass, and with the ends of 
the steps indicated by 8 and 9. 
The whole subject of passes and ladders is of extreme im- 
portance to our fisheries, and it is one which calls for the 
closest, most patient, and most scientific investigation ; for if 
fish are not allowed to reach their breeding-places, it 1s use- 
less to look for salmon; and the difticulty is how to deal with 
the vested rights of mill-dams, etc., so as not to arouse the 
opposition of the manufacturing sections. 
The following account of foreign experience tells with 
equal force in America: 
“T watched the fish with a race-glass for some ten minutes 
before disturbing them, anxious to observe what Nature was 
teaching me. There is a very deep pool at the point where 
the waterfall joins the lower level of the water. The fish 
came out of this pool into the air with the velocity of an ar- 
row; they gave no warning or notice of their intentions, but 
up they came, and darted out of the surface of the water with 
2 sudden rush, like rockets let loose from the darkness of the 
night into the space above. When they first appeared in the 
air their tails were going with the velocity of a watch-spring 
just broken, and the whole body, sparkling as though they 
had been enameled, was quivering with the exertion. They 
looked as much like flying-fish as ever I saw any thing in my 
life. As they ascended their tails left off quivering, for these 
tails were machines made to act on water, and not wings to 
act on air. Their course was somewhat trajectory in form, 
Dp 
