96 



bold eighteen wire trays placed one upon another. The 

 water enters from the bottom, passes up through the box, 

 falls evenly into little troughs which run around the four 

 sides, and is thence carried into a reservoir. The trays 

 are lifted for cleaning by arms at two sides ot the box 

 fastened into a lower frame. The trays are made of wire 

 cloth of so small a mesh that the eggs will not pass 

 through, but large enough to permit the passage of the 

 whitefish fry, which, as soon as they break the shell, are 

 carried up by the current and into the reservoir, from 

 which they may be taken out as required. Whitefish 

 eggs placed in one layer will number sixty-four to the 

 . square inch. Each tray will hold about 18,000 eggs, and 

 each box about 325,000. They can be made larger or 

 smaller and will work equally well. 



These boxes are the only device which will hatch white- 

 fish thoroughly well, for whitefish are the most delicate 

 and diflBcult to manipulate of all the salmon family. The 

 eggs are much smaller than those of the trout and the 

 fry are more tender than even the tender trout fry, which 

 test the fish cullurists best skill to raise satisfacti>rily. 

 One especial advantage is, the difficulty that sedi- 

 ment of any kind finds in lodging upon the eggs. 

 As it is carried upward, if at all by the current, it is 

 swept along over the upper rim into the reservoir, and 

 rarely catches upon the eggs. It has little opportunity to 

 settle, and the number of eggs killed by this fruitful source 

 of trouble is reduced to the minimum. Where the water 

 passes from above down, it naturally deposits whatever 

 it holds in suspension on its way, but by this reverse 

 process, the sediment cannot fall, and cannot cling to 

 what it touches, because it comes in contact with the 

 underside. The aeration of the eggs is perfect, none 

 are covered up by others so as to be shut out from 



