208 THE TROUT 



the water show a tendency to become heated, the 

 supply must be increased or you will run a serious 

 risk of loss. 



To have complete control over the supply, and 

 to be able to create an artificial ' spate ' by sending 

 down a flush of additional brook-water into your 

 ponds whenever you think it desirable, is a very great 

 advantage. 



The use of a Hornsby-Akroyd oil pumping-engine 

 at the Weston Fishery, for the purpose of increasing 

 at will the natural supply of brook-water during the 

 hottest days of the summer, has been attended with 

 great success. 



In respect to size, your ponds should be small for 

 rearing purposes. 'When you mean business,' says 

 Livingston Stone, ' build your ponds small ; never 

 let a trout escape to any place where you cannot get 

 at it, observe it, and capture it at a moment's notice.' 



The shape of your rearing-ponds will depend upon 

 circumstances ; generally it is convenient to have them 

 oblong. If the water supply is not very plentiful or 

 cool the ponds should be deep and narrow, exposing a 

 smaller surface to the rays of the sun. 



The quantity of water entering your ponds may be 

 regulated by a hatch at the intake. In front of this 

 is a sloping screen of perforated zinc designed to 



