48 AMERICAN FISH CULTURE. 



sent the flannel screens ; if there were four it would be 

 better. The water entering the first apartment on the 

 right, passes through the screens and flows into the dis- 

 tributing trough B, which by four jets supplies the troughs 

 c c c c. 



The troughs are thirty-two feet long, fourteen inches 

 wide, and four inches deep, inside measurement. Each 

 trough is divided into twenty nests eighteen inches long, 

 besides having an apartment two feet long at the upper 

 end, which is filled with fine gravel, through which the 

 water is again filtered as it passes into each trough. F is a 

 gravelled walk two feet wide. There should also be a grav- 

 elled space of the same width between the troughs and the 

 sides of the building. 



D D are the nurseries, three feet wide, and half the 

 length of the hatching-troughs. The lines which extend 

 alternately from each side beyond to the middle, represent 

 small bulkheads or strips, so placed for the purpose of 

 breaking the force of the current when an additional supply 

 of water is let in for the young fish, and to form eddies 

 where they find shelter from its force if they require it. 

 The latter is an improvement of the Rev. Livingston Stone, 

 of Charleston, New Hampshire, and was suggested for this 

 book by Theodore Lyman, Esq., one of the Massachusetts 

 Commissioners of Fisheries. The bottoms of the nurseries 

 should be of boards, and should be gravelled. The depth 

 should not be much, if any, over an inch at the upper end, 

 and four inches at the lower end. E is a channel leading 

 from the nurseries into the first pond. 



