46 Modern Fishcnlture in Fresh and Salt Water. 



Hatching troughs should be made with great care 

 1 prefer i|-inch plank, dressed both sides, which leave? 

 it over an inch in thickness. Have your carpenter get 

 out the bottoms of the best stuff and of an exact width 

 to a hair. This will allow screens, dams and trays to fit 

 all the troughs, and you will have a standard size foi 

 them. Insist on this. Never nail the bottoms to the 

 sides ; it takes wider bottoms, and is the wrong way to 

 do it. My favorite size for a hatching trough is 14 feet 

 long, 14 inches wide and eight inches deep, inside meas- 

 ure. If of I -J -inch stuff the side planks are 9^ inches 

 wide. Lay in white lead or thick coal tar. If in white 

 lead do not let it come to the surface of the bottom plank, 

 for coal tar will not dry over it. Rabbet the ends in the 

 bottom and sides, as shoAvn in the cut, and you can nail 

 both ways and make tight ends. 



When the troughs are made and dry coat them with 



End of Trough. 



coal tar from the gas works, thinned with spirits of tur- 

 pentine. Have it so thin that it will strike in and dry in 

 24 hours, in summer. Use a half-worn paint brush, and 

 when dr>- give it a second and a third coat. Be sure 

 that it is thin enough to be absorbed by the wood and 



