48 DOMESTICATED TROUT. 



Make it as small as you can without sacrificing 

 water. Cover it from dirt, leaves, and light. Keep 

 it perfectly clean, and never put any fish into it under 

 any temptation ; and finally, unless you are certain that 

 you can make a very sure thing of it yourself, employ 

 an experienced man to construct it for you. 



HATCHING-ROOM AQUEDUCT. 



One of the most important parts of the whole hatch- 

 ing apparatus is the aqueduct which takes the water 

 from the hatching reservoir to the hatching room. It 

 may be nothing but a simple short pipe or spout, but 

 its office is nevertheless exceedingly responsible. In- 

 deed, it is literally a sine qua non of a hatching 

 establishment to have this aqueduct safe; for if it 

 fails for a night to fulfil its purpose during the period 

 of incubation, that is the end of that season's opera- 

 tions, and unless you buy more eggs, there will be a 

 gap of one year in your chain of fish broods that never 

 will be filled up. 



This aqueduct, therefore, ought to be made espe- 

 cially secure. To make it so, i. Build it of i J-inch 

 or 2-inch plank, and fasten it firmly so that frost 

 cannot heave it, and so that it cannot be dis- 

 placed by any accident whatever. I have known 

 serious loss to result from an aqueduct being simply 

 pushed out of place by the foot. 



2. Char the plank. This I consider very important 

 indeed, if you use plank, for you cannot be certain, 

 without charring it, that fungus is not being generated 

 in it. Do not imagine that you are safe from fungus 



