382 Fisninc ix American Warers. 
BEST WATER FOR HATCHING SALMON, 
Pane) 
Spring water from 45° to 55° is probably the best. Spring 
water is preferable, as being more pure than river water even 
after being filtered, while its temperature is more equable, 
being nearer the same throughout the year. Too much sur- 
face or rain water is injurious, containing less vitality for 
game fish, but more predaceous insects, so that their larve 
may be mixed with the eggs in the hatching-boxes, and prey 
on the spawn before it is hatched. 
In situations where spring water can not be obtained in 
sufficient quantities, the river water should pass through a 
filter of sand and gravel. Ifthe spring is large enough and 
the ground suitable, it may be divided into artificial rills, 
with a pipe of two inches run of water to each. Under all 
circumstances, a gentle, equable, and pure current is indis- 
pensable, 
HATCHING-BOXES FOR THE INCUBATION OF THE EGGS OF SAL- 
MON OR TROUT, AS ADOPTED BY THE COLLEGE OF FRANCE. 
These boxes are fed from a horizontal pipe two inches in 
diameter, by faucets tapping it at every tier of five boxes; 
and to break the foree of the jet so that it will not derange 
the ova in the first box, and to assist in aeration, a perforated 
ainc cap is sometimes placed before it, as the object is to 
maintain a regular movement of the current throughout the 
tier of boxes, which are about six feet long and two and a 
half wide. A constant flow of water, of nearly equal temper- 
ature, through the boxes is a necessity. At Huningue, in 
France, all the hatching-boxes are in a well-ventilated Laild- 
ing; and as hatching-time continues from October until Feb- 
ruary, a cover to the hatching-boxes is essential; and in En- 
gland, to protect the ova from thieves, Mr. Francis recom- 
mended a cover of perforated zinc, with the ends which are 
above the water of zing also; and in order to regulate the 
temperature of the water, the horizontal pipe should be sup- 
