CULTURE OF THE SHAD. 169 



fish from the lower to the upper levels, for once or twice 

 that the Columbia dam has been broken, they have made 

 their way above it, and have been caught in small numbers 

 at Duncan's island. 



"But what Mr. Lyman says is . nevertheless true ; that 

 the fish will make almost irrepressible exertions to return 

 to the beds where they were spawned, while to pass beyond 

 there, they will take but little trouble. 



" The spawn (fry) of the few, however, that make their 

 way up, will return by resistless instinct in the following 

 season, and it may be well to consider his other recom- 

 mendation, that the fishing above the dam should be some- 

 what restricted by legislative enactment for a limited 

 period, until our great Susquehanna shall be cured of 

 ' barrenness/ 



" It remains for me to describe to you the device which 

 has been inserted in the Columbia dam. 



" The dam itself is about six feet high, and about a mile 

 and a third long, and is located on a rough, rocky bed. 

 The channel below is rapid and much interrupted by large 

 rocks, worn by the water. The fish channels in these 

 rapids are tortuous and much spread over the whole bed 

 of the stream 



" A point was selected within about a quarter of a mile 

 of the York county shore, where the fish ' most do congre- 

 gate' from all the lower channels every spring, and where 

 many of them have been annually taken; and at this 

 place a section, forty feet long, was cut clean out of the 

 15 



