38 PKACTICAL TKOUT CULTURE. 



lay up a rough wall and fill in with mud not 

 dry earth, nor even dampened earth, but liquid 

 mud. Allow this to remain until dry, and you will 

 have that rare article upon trout farms, a perfectly 

 tight sluice-gate. The frames of the screens should 

 be strongly made and mortised. Of these frames 

 it is well to have an extra supply on hand, that in 

 case of injury to one it may be at once removed 

 and another substituted. For leaf screens, galvan- 

 ized iron wires, No. 9, should be used, placed par- 

 allel, about three-quarters of an inch apart, witli a 

 transverse wire every four inches to prevent bend- 

 ing and falling out. The fish screens (Fig. 3) 

 should be made of wire gauze from one-eighth to 



Fio. 8 



five-eighths of an inch mesh; the smaller sizes 

 (say to three-eighths) of copper or brass ; the 

 larger may be of iron, painted or galvanized. If 

 kept well painted they will last a long time, even 

 under water. The wooden frames should be 

 thoroughly painted, and a japanned iron handle 

 attached to the top will be found very convenient. 

 Shade, which is absolutely necessary for trout, 

 is best furnished by trees which, as previously 



