HATCHING APPARATUS. 53 



no water should be allowed to pass over the eggs any 

 length of time, without having first run through this 

 tank. The tank need not be covered. 



The Distributing Spout. 



The next thing in order is the distributing spout, 

 the office of which is simply to receive the water from 

 the filtering tank, and distribute it into the various 

 hatching troughs. 



It joins the filtering tank, and extends, of course, 

 either way, as far as the hatching troughs reach later- 

 ally, over which it is placed. 



It is provided with an outlet at the head of each 

 trough, and it will be found a convenience to have all 

 these outlets levelled so as to each draw an equal 

 supply of water when they are open. To secure this, 

 the openings farthest from the inlet screen should 

 be a little lower than the next, and so on, for the 

 water at the inlet will be a little higher than the 

 other end. If built of wood, the distributing spout 

 should be of ij-inch plank, charred, and should be 

 abundantly ample in width and depth for its purpose. 



There should also be an aqueduct connecting the 

 water supply above the filtering tank with the dis- 

 tributing spout, so that the water can be temporarily 

 turned directly into the distributing spout when it 

 becomes necessary to wash the tanks. 



The distributing spout often has gravel placed in it 

 for an additional filter. This is a good plan, because 

 the gravel gathers up whatever fine sediment may 

 have run the gantlet of the flannel filters, and any 



