152 THE TROUT 



the level of the water outside will allow. To secure 

 more complete exposure to the air I recommend that 

 the water should be sprayed into the trough through 

 a punctured pipe after the fashion of the sprinkler of 

 a city water-cart. 



The trough which I have just described is called 

 the distributing tank, because its primary object is to 

 distribute the water-supply in such a way that each 

 hatching-box or range of boxes may receive its proper 

 share of water. Outlets therefore are made in the 

 distributing tank corresponding to the number of 

 rows of boxes to be fed ; and each outlet is provided 

 with a screw-tap. These screw-taps will enable you to 

 regulate to a nicety the supply sent into each box. 

 Pieces of india-rubber piping of the required length 

 serve to conduct the water from these taps into the 

 hatching-boxes. Near the top of the distributing- 

 tank there should be an overflow-pipe, and this should 

 be kept always running. 



THE HATCHING APPARATUS 

 The contrivances for incubating and hatching the 

 ova are very numerous. Here, however, I propose to 

 describe only one ; but this one I can thoroughly 

 recommend, having myself employed it for many years 

 with the most satisfactory results. Simple in con- 



