MANUAL OF FISH-CULTURE. 81 



hillside, one above tlie other, with eartli and piling embankments on 

 the lower sides and at the ends. A pond of this kind is shown in 

 plate 25, and is the one here described. Various materials may be used 

 for damming the water. The embankments may be made altogether 

 of earth or lined with stone, brick, cement, or timber, according to 

 circumstances. Where the ground is of a porous or loose formation it 

 is necessary to use piling or cement for the inside of the embankments 

 and possibly cement for the bottoms, but earth bottoms are best where 

 the nature of the ground permits. The water enters the pond at one 

 end and discharges from the lowest opposite corner. The bottom is 

 graded as shown in the cross-section, plate 25, with a slope toward the 

 outlet, so that when all the water is drawn out the fish are led into the 

 receiving trough (C), the top of which is flush with the earth bottom in 

 that part of the pond. 



The outlet for the water is an L-shaped pipe, shown at F, and is 

 placed in the corner of the pond, the long end passing through the 

 piling and underneath the pond embankment; the short end, called 

 the standpipe, stands close to the inside corner of the pond, in an 

 upright ijosition. The standpipe has two or more holes cut through 

 (G) on the side next to the receiving-trough, to let the water pass out 

 in drawing down the pond. The size of these holes is in proportion to 

 the size of the standpipe, which, in turn, is governed by the sue of the 

 jjond. The holes may have blocks of suitable size tacked over them to 

 allow the pond to fill with water, or, what is more convenient, covered 

 with blocks arranged to slip down in grooves, one block resting on the 

 other. Surrounding the standpipe is a crib, the front of which is 15 

 inches or more from the pipe and contains an opening for a guard 

 screen, which is 14 to 10 inches wide and made with copper or galva- 

 nized wire cloth, the size of the mesh depending on the size of the fish 

 in the pond. In the bottom of the pond is a receiving-trough (C) for the 

 fish, built in proportion to the size of the pond; 10 feet long, 10 inches 

 wide, and inches deep i^ a satisfactory size for a pond like the one 

 described. This trough extends to and connects with the standpipe, 

 and the guard-screen is arranged to fit down on the inside. Every 

 part is made secure, to prevent fish from escaping when drawing off the 

 water. The supi)ly-trough or pipe is arranged to keep the fish from 

 jumping into it from the pond, as shown at A. 



STOCKING THE KEARINa-PONDS. 



The rearing-ponds at Wytheville are stocked gradually, 500 to 1,000 

 fish being i)hiced in the jiond and trained to take food before more are 

 added, as that number can generally find enough natural food to sub 

 sist upon until they learn to take artificial food. When they have been 

 accustomed to hand feeding another 1,^)00 fish are added, and in about 

 ten days 2,000 more, this practice being continued until the pond is 

 stocked with the desired number. When fish are first released in ponds 



r. c. n. is'JT — 6 



