156 THE TROUT 



breakwater, when the water is running over the lower 

 breakwater, and prop it very securely in this position. 

 The water, released from the distributing tank by 

 turning the screw-tap, enters the hatching-box, and is 

 headed up by the first breakwater. Over this a 

 broad strip of zinc, laid evenly along the top, shoots 

 the water clear into the compartment below, creating 

 a miniature waterfall as wide as the box. The current 

 is thus distributed evenly, and the water thoroughly 

 aerated at the most important point in its course. 



Passing through the first compartment, and 

 through the first screen, the current is arrested by the 

 second breakwater, which keeps the water above it at 

 a constant level. In the same way the head of water 

 in the last compartment is prevented from falling or 

 rising by the outlet-end or tail-board of the box, 

 and is ultimately discharged by the shoot attached 

 to that end. All the zinc parts of the apparatus, 

 whether fixed or movable, are varnished with Japan 

 black to prevent them from corroding. 



Let us now turn our attention to the central point of 

 interest, the actual receptacle or nest in which the eggs 

 are to be ' nursed into life.' This is a form of what is 

 known among fish-culturists as a deep tray, so called 

 because in comparison with other forms its sides are 

 less shallow. The tray is made of perforated zinc (size 



