STAIRS FOK THE FIRST FAMILIES. 417 



This pass is built into the dam, and constructed of heavy 

 timbers filled 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 is use- 

 less to look for salmon ; and the difficulty 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 : 



" I 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 

 a 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, 



DD 



