242 SEASON 1877 78. 



turning it down the 4-inch pipe to B. At B the 4-inch pipe is 

 closed by placing in the cross-boards and filling between them with 

 clay, while the leg is opened by removing the clay between its 

 cross-boards, and lifting them out, thus throwing the supply into 

 the trough running from the outlet screen-box of the upper to 

 the inlet screen-box of the lower, the fall in this trough being 

 sufficient to prevent the water passing back into the upper 100-feet. 

 The upper pond is then drawn by depressing the upright copper 

 stand-pipe, first protecting its mouth with perforated zinc, if it is 

 wished to retain the fish in the pond. This, however, is not now 

 requisite at Craigend, as will be presently shown. 



If the lower pond only is to be drawn, the screen of the inlet 

 screen-box is lifted (it is hinged for convenience), and well- 

 milled clay prepared. A thin board, fitting easily in the trough, is 

 inserted as a face to the clay, which is next plastered in, and 

 rammed so as to enter and fill 6 or 7 inches of the trough. A 

 second board is then fitted, and held in position by means of a 

 ranch driven tight against the lower end of the screen-box. This 

 of course forces the water vented by the outlet screen of the 

 upper pond through the connecting-pipe to the leg of the three- 

 legged trough, through which, all clay and cross-boards being 

 removed, it finds a free passage, past the lower 100-feet pond to 

 the next three-legged trough, where it can be turned on to supply 

 the octagon or to waste, as desired. Of course the screw sluice at 

 the leaf-screen in the wood is lowered to reduce the quantity 

 of the supply whenever any of the ponds are drawn, otherwise 

 the 4-inch pipe would be insufficient, it being only 4-9ths of the 

 capacity of the 6-inch. Below is a plan showing the pipes and 

 connections of these ponds in detail. 



The octagon pond was emptied, and having been useful for 

 experimental lots, though too small for work, I increased its 

 capacity by deepening it and building it, like the GO-feet and 

 130-feet, of wood. The shape was at first a difficulty, but by 

 packing the outside tight with very wet puddle, the form of the 

 pond enabling it to bear great crushing strain, I overcame all 

 tendency to spread at the corners, and the pond has remained 



