ARTIFICIAL PROPAGATION OF TROUT. 57 



feet long, by twelve feet wide, and five feet deep. 

 Unmatched hemlock lumber, an inch or an inch and 

 one-half in thickness, is suitable for the purpose. 

 The ground is measured and staked off to the de- 

 sired dimensions. The excavation is made as if for 

 one pond, and stakes are driven at regular intervals, 

 a few feet apart, around the entire excavation. If 

 the bottom is made of lumber which is necessary 

 if the ground is porous that should be laid first ; 

 scantling should run across the bottom and be at- 

 tached to the stakes around the sides of the pond, 

 upon which to lay the bottom. If the bottom is 

 made of lumber, the pond can be kept cleaner and 

 the water is always clear. After the bottom is laid, 

 the sides should be enclosed with planks running 

 lengthwise, and not straight up and down, for the 

 reason that the wood between " wind and water " is 

 always the first to decay. By placing the planks 

 lengthwise, new ones can be substituted with but 

 little expense ; whereas if the boards are m perpen- 

 dicular position, it would necessitate an entire 

 change of lumber. 



A double partition extends through the centre of 

 the excavation ; the space between the sides should 

 be about two feet in width and filled in with earth. 

 This strengthens the sides of the ponds, and also 

 affords a walk between them. The two sides are 

 then partitioned off into compartments of equal 

 sizes. The ponds on each side of the central divi- 

 sion should have openings of about three feet in 

 width between them, into which screens should be 

 introduced, so as to keep the fish separate and yet 

 allow the water to flow through. The screens 



