37 



A very good screen for two and three year olds can be 

 made from strips of lath planed and nailed to a strong 

 frame, with quarter-inch openings between them. Or, 

 what is better, the slats should be at least four inches 

 wide so that if a leaf strikes against them it will catch 

 without obstructing the flow of water and lie flat against 

 a single slat, or if it reaches over the edge it will be car- 

 ried through by the current striking upon one end. It 

 cannot lap around the slat as it would if it were smaller. 

 As for the width of the slats from one another the point 

 to be guarded against is the fish running their heads 

 through far enough to strike their eyes which will pro- 

 duce blindness. The distance they are to be apart will 

 depend consequently, mainly on the size of the heads of 

 the fish, and as fish grow at difterent rates of speed it 

 will not do to go merely by their age, but for fair sized 

 fish an opening of about five-eights of an inch will 

 answer. This refers to the upper screen, the lower 

 screen, that at the foot of the pond, may be larger as the 

 fish are more cautious about descending where they can- 

 not see their way, just as a man will climb a hill in the 

 dark at his best speed, but will go down very cautiously. 

 WATER SUPPLY. It is immaterial what kind of water 

 is used, whether hard or soft. Neither will so-called 

 " mineral water " hurt the trout unless the water is very 

 stongly impregnated. Trout have been known to live 

 and thrive in a stream one-sixth of whose volume was 

 supplied by a strong sulphur spring. The essentials are 

 that the stream shall be reasonably pure, the volume of 

 water nearly uniform or so arranged that the supply 

 taken from it is uniform and the temperature between 

 thirty-six and sixty-five degrees. 



One peculiar fact has been noticed in reference to the 

 eggs which is important to those persons who collect 



