How to obtain it. 133 
very handy. Should it be found desirable to have something 
larger get one made like Fig. 9. A hook can be placed in the 
loop with which it is furnished, to lift it from the fire and drag it 
along by when being used. 
For charring the grooves Fig. 10 will be found very useful, 
and for the plug holes I use an iron shewn by Fig. 11. The 
object of charring the wood is to prevent the growth of a fungus 
(Saprolegnia) that is very deadly amongst ova and fish. It grows 
vigorously on wood, but will not grow on carbon. By thoroughly 
carbonizing the apparatus, therefore, a great danger is to a 
considerable extent averted. The process should be carried out 
by a steady-handed careful man, as the wood requires to be very 
evenly burnt. The carbon wears off in time, and each season I 
give my boxes a coat of black varnish, and sometimes two. Some 
fish culturists repeat the carbonizing process each season, but the 
varnish is by far the most economical, and answers quite as well 
after the former has been once done. 
In the charring the heat opens the seams of the boxes, and at 
times causes the wood to crack, and it certainly has a tendency to 
make the joints leaky. The varnish has just the contrary effect : 
it fills up small crevices, and tends to make the boxes watertight, 
which is a great advantage. I got mine first from the United 
States, where it is largely used, but have since found out a way of 
making a varnish which answers admirably. There are many 
varnishes in the market which will do, but as the use of some of 
them is at times attended with danger, I shall be glad to supply 
anyone with that used at the Solway Fishery, which I have found 
to be perfectly safe. 
At the head of each hatching box a board is fixed in a 
slanting position to act as a breakwater. About an inch of space 
is left underneath it, and the water is thus directed under the 
grilles, which should be about one and a half inches above the 
bottom of the box. Slates do very well instead of boards, and it 
will be found very desirable to have a pile of them at hand for 
this and similar purposes. They are easily worked to any size or 
shape, and are very useful about a hatchery. They are clean, and 
give off nothing, and need neither charring nor varnishing. A 
number of small water boards will be required for placing in the 
