FOR PLEASURE AND PROFIT. 



73 



I strongly recommend the contrivance wherever a slight fall 

 only occurs from pond to pond, or from supply to first pond. 

 It may be used separately or in conjunction with an ordinarv 

 fall. 



The chemical analysis that I have recommended should be 



if favourable sufficient guarantee of the suitability of the 

 water supply ; but a few hints concerning this may not be out 

 of place. Even in the neighbourhood of limestone or iron 

 caution should be exercised. That trout live in such districts 



AN AERATING GRATING. 



goes beyond saying ; but the foTmation of a fish-farm, at which 

 the most favourable conditions should, if possible, exist, is 

 quite another matter. Pollution from lead ore or " blend " 

 spells failure in all cases. Other pollutions to be especially 

 avoided are those resulting from gas-works, distilleries, tan- 

 neries, and some descriptions of paper-mills. It is foolish to 

 form a fishery in the neighbourhood of any of these or of simi- 

 lar industries. 



A low temperature water produces hardier brown trjut. 

 This fact should always be taken into consideration where 

 choice of water supply is concerned. On the other hand, rain- 



