72 How to obtain it. 



stock of food can be reproduced. Especially is this the case 

 when the pond is supplied by means of springs, or the compara- 

 tively barren water of mountain or moorland streams. For this 

 reason, a pond should never be let off unless for some very special 

 purpose, as, for instance, when it may become needful to clean it 

 out, or to change the stock of fish, or possibly to destroy pike or 

 some other predacious fishes, which may have been introduced 

 accidentally or otherwise. 



There are many ways of constructing a bottom outlet, the 

 great need being to have one that will allow the water to escape 

 without at the same time letting go the fish. This outlet should 

 be made at, or rather below, the level of the deepest part of the 

 pond. In the case of a large reservoir, where there is much 

 pressure, the pipes by which the water escapes should be of iron, 

 and should be very strong ; but for a small pond, or one where 

 the water is not very deep, good sound earthenware pipes will 

 often answer the purpose. I would here point out the necessity 

 that exists, in the construction of embankments and bottom 

 outlets connected with ponds of any size, for the employment of 

 a thoroughly competent engineer. So much often depends upon 

 the strength of a bank, that too much caution cannot be observed 

 in attempting to impound any considerable amount of water. 



I was once sent for to inspect a pond of some fifteen acres 

 after it had been completed, with a view to advising as to the best 

 course to pursue for getting up a good head of fish. I had never 

 seen it before, and when I arrived I found it nearly full, and 

 during my examination naturally asked a few questions as to the 

 embankment, puddle trench, etc. This not being really part of 

 my work, I did not say too much about it, but strongly advised 

 caution, and the water was not allowed to rise to its highest level 

 for some time, and then only very slowly. The bank was closely 

 watched, and, as the filling went on, the water was discovered 

 percolating through, and the owner at once ordered the bottom 

 outlet to be opened. The outlet pipes were of earthenware and 

 of considerable size, and as the foaming mass of water came 

 pouring through them, it was observed that the .pipes were 

 breaking up and going away down stream. Fortunately the 

 embankment stood, but it was a narrow escape, and I have 



