practical papers—fish culture . 
401 
good for food for the young, and that probably a variety is better 
than feeding on one thing alone. 
Filters .—All the water which entered the hatching-house used 
to be passed through a large filter. The plan now generally 
adopted is not to filter the water at the entrance, but as it passes 
out of the supply-trough into the hatching-troughs. This is ac¬ 
complished by means of one or more flannel screens laid under 
the spigot which supplies the trough. The advantage of this ar¬ 
rangement is that it is necessary only to filter the water used for 
hatching, and not to clean two or three inches of water for the 
sake of using one quarter inch. Besides this, the small screens 
are more easily cleaned, none of the dirt is spilled in removing 
them, and enough of them can be used to thoroughly clean the 
water. 
A little sediment is also not minded so much as formerly; and 
there has come into use a watering-pot with fine rose-jet for 
the purpose of sprinkling and thus cleaning the eggs when sedi¬ 
ment has been deposited upon them. The introduction of the 
watering-pot into the hatching house is due to Mr. Samuel Wil 
mot, superintendent of the Canadian government hatching-estab¬ 
lishment. It is most effective, however, when the eggs are 
hatched out on trays. As the method of hatching on trays is not 
generally known, and is not, we believe, mentioned in accessible 
books, it will be briefly described here, as used in the New York 
State hatching-house, at Caledonia. The troughs are made four¬ 
teen inches wide (inside) and six inches deep. Iron-wire cloth, 
of ten or twelve meshes to the inch, is stretched tightly upon 
wooden frames, whose sides are one inch wide by one-half inch 
deep, the screen being a little less than fourteen inches wide, in 
order to tit easily into the trough, and about two feet long. One 
quarter inch strips are also nailed under the two long sides. The 
water is raised nearly to the top of the trough, and four or five of 
these wire trays filled with eggs can be placed on top of one 
another. No filter is used, as more water is required than in the 
usual plan, but as soon as sediment settles on the eggs, an empty 
trough is cleaned and the trays of eggs are taken out one by one, 
sprinkled with the watering-pot, and set over, bright and clean, 
26 
