116 FISH CULTUEE 



broad windows so that the buildiBg can be well 

 lighted in the daytime; but these should have 

 either solid inside shutters or be provided with 

 curtains, so that the interior of the building may 

 be darkened when desired. Darkness, or rather 

 gloom, is an important factor in the successful 

 hatching of eggs and rearing of fry. It is well 

 to have at each end of the building doors wide 

 enough to permit even bulky objects to be taken 

 in and out. Of course aU the outside lumber 

 should be planed so that the building can be 

 painted. It is poor economy not to be liberal 

 with paint, to say nothing of an unsightly ap- 

 pearance ; and thought should be given to taste- 

 ful colors, avoiding white. 



Arrangement of Troughs. — ^For a building of 

 this size the troughs had better be set in three 

 tiers if it is at all possible to do so, which wiU 

 permit the use of 120 troughs and a maximum 

 of 120 gallons of water per minute. If this 

 method is adopted the water is conducted into 

 the building at the upper end and on one side 

 of the house, and flowed into either an iron sup- 

 ply-pipe or wooden supply-trough 12 inches 

 wide and 14 inches deep, which extends the 



