12 
the lower end where the fish will gather when the water is drained down. 
Ditchs dug in the bottom of the pond leading to the deep hole or “kettle,” 
will greatly facilitate the concentration of the fishes at that time. - 
Two or three ponds will be found to be much more satisfactory than one, 
since they will permit of the sorting of fishes according to size. Angling or 
other fish catching will then naturally be confined to the ponds containing 
the larger fishes. If properly managed a series of fish ponds wil) naturally 
yield a surplus for the market. It is dangerous to construct a fish pond in 
a narrow ravine, as the dam is liable to be broken during the spring fresh- 
ets or exceptionally heavy rains, and the pond will gradually fill up with 
silt. Even if the embankment is not broken during high water, it is~ diffi- 
cult to screen it so that the fishes will not escape. A safe plan is to make 
the pond at one side of the stream by excavation and embankments leading 
the water to it through a ditch and damming the stream. sufficiently at the 
ditch head to divert a portion of its flow. In case of freshets the deep 
pool formed in the stream by the dam at the ditch head naturally receives 
the silt brought down the streams, thus guarding against the filling up of 
the fish pond. The ditch itself should be screened at both ends to -prevent 
the ascent of fishes to the stream and keep floating drift out of the ditch. 
If the pond can be excavated in marshy ground, so much the better. A 
layer of clay on the bottom will render it more water tight than it would 
be otherwise... The embankment should be broad and before it is thrown up 
all sod should be removed so that there will be no subsequent seepage caus- 
ed by the decay of vegetable matter. ‘ue earth used for the embankment 
should also be free from sods or other matter liable to decay. The ground 
cleared for the embankment should have a ditch extending its full length 
into which the new earth will settle, thus increasing the stability of the 
dam. ; : 
The embankment of the dam if it is to be six fet high should be ten or 
twelve feet wide at the base and four feet broad on top. The earth used 
in its construction will naturally be derived from the bottom of the pro- 
posed pond, which will, of course, serve to increase its depth. The overflow, 
should be large enough to carry the surplus, when the water is high, with- 
out danger to the dam and the outlets in general should be screened with 
wire netting to prevent the escape of fishes. The drain for drawing off the 
water shuld, of course, be put in place before the dam is thrown up. Earthen 
draiu pipes are risky, as no matter how closely the joints may be set and cec- 
mented, plant roots will eventually find their way inside and clog them up. 
Iron pipe of not less than four inches diameter with the joints well soldered 
is more reliable. A hollow log will serve the purpose of a drain pipe, and 
wear well. If the drain, or bottom outlet, is built of concrete and large 
enough to be conveniently cleared, it would be more effective in lowering 2. 
large area of water. The upper end of the drain should fit tightly into the 
foot of the upright penstock in the pond. The penstock itself is merely an 
upright drain or sluice of planks or concrete, having about the same capac- 
ity as the drain pipe itself. It is fitted on one side with short “‘water boards” 
sliding in grooves which can be removed one after another, to permit the 
escape of the water. A heavy plank should connect the head of the pen- 
stock with the top of the dam. 
Before the new pond is filled, all roots, stumps, rocks and everything else) 
that would prevent the free sweep of a net along the bottom should be re-. 
moved. All ponds, whether natural or artificial, accumulate debris of which | 
they can not be cleared, except when empty. A muddy pond will give the! 
fish a muddy flavor. When a pond is being cleaned it is necessary to re- 
move the fishes from the deep hole or kettle. Any attempt to remove de-| 
cayed matter and sediment while fishes still occupy the deeper portions of 
a pond may be fatal to them, as dangerous gases are then liberated among 
the crowded fishes. If the pond is very foul, it should be only partially 
lowered at first and the fishes removed with a seine. With a reserve pond 
or two it is possible not only to thoroughly clean a pond but to “winter” it; 
2 
Bo! 
