70 FISH FARMING: 



of redds and lakes and described the apparatus connected with 

 their construction, it must not be thought that I have lost 

 sight of the vast importance of the present subject. 



As a matter of fa^t, a fisherv without a proper water supply 

 would be like the play of " Hamlet " with the Prince of Den 

 mark left out. I would so even further, and assert that the 

 water supply is the heart's blood of the whole concern. I 

 credit it with so much importance, indeed, that I recommend 

 a proper chemical analysis of it being made before it is used for 

 fish-farming purposes, even though the supply be copious ind 

 to all appearances perfectly pure. More than one fish -farm in 

 this country and in others has come to grief from lack of 

 water or from impurity of the supply. Therefore, where you 

 are not absolutely assured of the purity and volume of your 

 water supply do nob attempt the construction of a fishery. 



Some waters that are admirably suited to the requirements 

 of incubation are absolutely useless for rearing purposes. But 

 these may be made suitable after the manner to be presently 

 described. It may be taken for granted that a, water rich in 

 natural food is to be preferred for ponds, etc., while that direct 

 from a spring of almost perfect purity is best for incubatijn. 

 I have previously pointed out that temperature has much to 

 do with successful fish-farming, and I only refer to it here 

 again in order to emphasise the fact that it should guide you 

 in a choice of water supply. But do not condemn a water 

 supply that "warms up" in summer time until you have 

 exhausted the possibilities of shading by means of planting 

 trees or other methods referred to elsewhere ; for many of these 

 " warm " waters are rich in natural food. And it must not be 

 forgotten that rainbow trout can be reared in water of much 

 higher temperature than can brown trout, and I am quite 

 convinced of the usefulness of rainbow trout in this country if 

 they be planted under proper conditions. 



Where it is possible to store your water, in order to guard 

 against a shortage in summer time, do so by all means ; and in 

 this connection mill-heads and lakes in high altitudes are often 

 invaluable adjuncts to a successful fish-farm. But pure spring 



