148 THE TROUT 



Is it ample, and will it continue ample always, day 

 and night ? Will the flow of water, like Tennyson's 

 Brook, * go on for ever ' ? 



In this respect it should be able to stand the 

 severest test ; even after prolonged drought the stream 

 must still continue to flow in plenty. If it will do 

 this, well and good ; if not, then look elsewhere for 

 your water supply. 



But this is not all. The opposite extreme must 

 be guarded against. It is not of course a disadvan- 

 tage to have a greater supply of water than you 

 require to take, but there must be no risk whatever of 

 flooding ; the situation must be one in which you 

 will under no circumstances lose the power of control 

 and regulate your flow of water as you may think fit. 

 Nor must the water be liable to become overheated in 

 the summer through exposure to the sun. Beware of 

 water, the temperature of which is liable to rise above 

 70 degrees Fahrenheit. If you limit your operations to 

 hatching a small number of eggs and rearing a corre- 

 spondingly small number of fry, all this can, with 

 suitable apparatus, be accomplished readily by means 

 of the ordinary domestic water supply of a town or 

 country house. 



I recommend you to protect your spring or supply- 

 cistern with a closely fitting cover to exclude animals, 



