Fish Culturists' Association. 41 



. The people of Maryland riprarian in the lower Susquehanna have 

 observed a change for the better in their fisheries. They have done 

 nothing to effect this, and the conclusion is inevitable to them that their 

 neighbors up the river have been doing something, so that they are now 

 exceedingly anxious to know what the}' shall do to aid and abet in the 

 good work. There is scarcely any doubt that a commission will be 

 appointed for that State at their present session of the Legislature. The 

 abrasions in the Columbia Dam of 1873 were not easier of ascent for the 

 shad than those of 1867. Yet the most extravagant claim for the catch 

 of 1867 above the Columbia Dam was 20,000, the estimates var^ang 

 between 12,000 and that number. If the fisheries of the river had not 

 improved then since 1867 how could 50,000, (the number justl}- claimed,) 

 be caught in 1873, whilst the utmost amount for 1867 did not exceed 

 20,000? In both years every available seine was employed. 



It is entirely fair to infer that a large natural spawning took place year 

 after year above the dam in years when there were abrasions of the dam 

 as well as in years when there were not. The dam was originally so 

 unfortunatel}" located that abrasions have followed each other regularly 

 on the recurrence of a severe winter as often before 1866 as since that 

 time. But before 1867 there was no regular annual increase. There 

 would be a good year and a bad year, due almost alone to the abrasions 

 of the dam, the number ascending the navigation chutes being always 

 very small, the great bulk of the runs of shad missing their mouths 

 probably from their out-of-the-way locations. 



There are navigation chutes in all the dams, j^et shad only seem to 

 ascend the first and second of them. The Shamokin Dam, just below 

 Sunbury, has a large chute in it, A^et shad, it may be said, are never 

 "caught above that structure. Yet, up to last year it was only about a 

 foot higher than the Columbia Dam, say seven feet five inches, the 

 Clark's ferry dam, up the chute of which a few alwa^'S have passed, being- 

 seven feet in height. 



• When ordered b}^ the Senate of Pennsylvania in 1871, to make a Report 

 on Fishways, the undersigned again called upon his friends, the Massa- 

 chusetts Commissioners, and with the experience gained up to that time, 

 they agreed with him that the simple inclined trough was the best for low 

 dams and shad. The gentler the inclination of course the better. 



When the Pennsylvania Commission was appointed, with money in 

 their hands to construct fishways, they adopted the idea of the inclined 

 trough, employing the undersigned as engineer to construct it, and to 

 make assurance doubly sure, reduced the inclination from 1.15 to about 

 1.35, whilst they added fifty per cent, to the width of the opening in the 

 dam. They, however, regard the success of the old chute with incre- 



