42 FISH FAEMING I 



B B is a section through the length of the pond, and it is 

 purposely broken at c to avoid the drawing taking 

 up space to no purpose. The sides and ends of a pond 

 should be dug at an angle of 45deg. to the plane 

 of the surface of the water, and there should be a shelf, D, 

 about eight inches wide and four inches from the top of the 

 soil, E, which materially guards against the washing arway of 

 the bank from the incessant action of the water, and is other- 



OUTLETS FROM HORIZONTAL BOX SCREENS. 



wise useful. Pond A should be at least one-third shallower, 

 and it may be even less than half at the inlet end than it is at 

 the outlet end, which should be the deepest part, if only to 

 facilitate the handling of the controlling sluice. The sides, 

 ends, and bottom may be puddled, if necessary, or they may be 

 lined with planks, as already stated, but the natural soil is 

 best. A convenient size for a yearling pond is 50ft. by 10ft. 

 Never get your ponds for rearing purposes too large. The 

 depth of ai pond depends upon its situation and the average 

 temperature of the water in it. What you have to guard 

 against is your ponds " wanning up " in summer time ; there- 



