SALMON AND TROUT CULTURE. 447 
Economy in space, where operations are conducted on a 
large scale, is unquestionably a great advantage : but it is not 
only in space that the saving is effected : there is a saving also 
in the cost of building and fitting up the hatching-house, as 
well as in the quantity of water required—the last an important 
item of expenditure in many hatcheries. 
Whatever be the fashion or materials of the hatching 
SKETCH OF WOODEN HATCHING TROUGH. 
3 feet long by r2 inches wide and 5 inches deep. 
troughs, they should be placed in a good light, and arranged so 
that they can be easily manipulated for removing the fish and 
cleansing. Some hatching troughs are placed in out-of-the-way 
dark corners, where there is no possibility of seeing what is 
going on, and a great deal of mischief is done before the cause 
is found out. The cut represents the hatching troughs in my 
hatchery. 
As before stated, the whole of the inside of the troughs and 
the perforated trays should be coated with tar varnish or paint, 
