66 How to obtain it. 



The next question is What is the best kind of screen? 

 There are several important points to notice. 



(1) A screen should fit well into its place. 



(2) It should be strong. 



(3) It should be well let into the bank at each side, and 



especially underneath, so that the water cannot by 

 any means flow round it or underneath it. 



(4) It should be large enough. 



(5) It should be so constructed that it will not allow any 



fish to escape. 



Only on very rare occasions have I come across screens that 

 possessed all these qualifications. In travelling about the country 

 inspecting ponds and lakes, I have not found one piece of water 

 in fifty to be possessed of such a screen. Many have been 

 introduced at my suggestion, and have worked most successfully. 

 The proper working of a screen depends largely upon the man in 

 charge of it. Occasionally, one meets with an individual whose 

 .mind is made up before he sees it or begins to attend to it, and 

 in such hands it has usually a poor chance. I have seen one that 

 would not work at all under the care of one man do its work 

 admirably when in charge of his successor. 



There are several different forms of screen which we will 

 consider by and by. Before doing this, however, let us turn our 

 thoughts to the material of which they are to be made. I have at 

 i present close upon a hundred screens working about my ponds, 

 I and I have always used perforated zinc, and have found it to work 

 well. If is fitted on to wooden frames, and these being all of the 

 same size, one can be withdrawn, and another of coarser or finer 

 perforation be readily put in its place. This on a fish farm is very 

 necessary, as large fish may be taken from a pond and replaced by 

 small ones needing a finer screen. Perforated zinc works well, is 

 not expensive, and is easily manipulated by any one who can use 

 a hammer and nails. Should a hole get punched in it by accident, 

 it is easily repaired by lacing another piece over the hole with the 

 help of a little brass or copper wire. Ordinary zinc requires 

 renewing about once a year, and this is its only drawback, but to 

 set against it is the advantage it possesses in being so easily put 

 on. It can be obtained of considerable thickness, however, and 



