60 



FISH FARMING I 



zontal box screen may have strengthening sides, as shewn at 

 c, in Fig. 18. The reason why the slanting screen should 

 generally be made with the strengthening sides is that it is 

 much deeper in any case than the horizontal screen. In the 

 drawings E are strongly framed sides of wood, or they may be 

 built up of brickwork or concrete; D is the slanting screen, 



Mi 



A SLANTING SCREEN. 



which rests on a strong framework of wood; and c are the 

 sluice boards, manipulated in exactly the same manner as 

 those in connection with the controlling sluice. The 

 arrows show the direction of the current. The water 

 passes between the sides E, through the screen D, over the 

 adjustable sluice boards c, and so into the next pond or into 

 the surplus water channel. 



The next photograph is of part of a big screen across the 



