FOE PLEASURE AND PROFIT. 121 



Failing any better supply, a mill-head or some embanked 

 water may be tapped, passed through a settling bed, and so 

 to the hatchery. But, whatever, the method of obtaining 

 the necessary supply may b?, this, lot me repeat, is essential : 

 A continual supply, which is pure and remains at a low tem- 

 perature during the operations of incubation and hatching. 

 Settling beds should be of ample depth and size, and they 

 .are best constructed of brickwork sides and concrete bottom. 

 This in order that they can be thoroughly cleaned from time 

 to time, with least amount of trouble. Where any debris is 

 "brought down through the supply and into the settling bed, 

 r. lot of trouble may ba avoided by placing seme framed per- 

 forated zinc around the inlet, as shown in the illustration, 

 which is from a photograph of a contrivance in use at Mr. 

 Silk's fishery, at Wansford. If the water has to come from any 

 distance it is best conveyed underground from the supply to 

 the settling bed; and, in most cases, it becomes absolutely 

 necessary to convey the supply from the settling bed under- 

 ground to tli3 hatchery. Glazed earthenware pipes are best 

 for this purpose. The reason for conveying the water under- 

 ground is to guard against stoppage of supply by the water 

 becoming frozen, but it also prevents possible contamination. 

 Constant attention must be given to the inlet cf the settling 

 bed. so that it does not become choked by debris or ice. The 

 outlet from the settling bed should be well below the surface 

 of the water, but not nearer to the bottom than about two 

 feet. It should be of ample size, and should be protected by 

 a slanting screen a, pair of screens, one of much finer perfo- 

 ration than the other is better and a sluice should be added 

 in order to control the bulk of water supplied to the hatchery. 

 The exact amount of water run over the eggs is arranged for 

 in a manner to be described presently. 



Whether you convert an existing building to the purpose 

 or erect one especially, as with the water supply, so with the 

 building; it is of great importance to guard against frost. In 

 other words, tha water supply inside the hatchery should 

 never reach freezing point. To avoid this is not so difficult 



