78 REPORT OF COMMISSIONER OF PISH AND FISHERIES. 



fish to ascend to the head of the trough and receive the water as it falls 

 from the screen, which is very beneficial. Its use not only keeps the fry 

 clean even in muddy water, but also reduces the'loss of fry from suff"©- 

 cation in the early stages, caused by their banking around the vertical 

 screens, and obviates the necessity for trough covers to prevent jumping, 

 as trout rarely jump where the horizontal screen has been adopted. 



LONSITUDINAL SECTION OF HATCHING THOUGH.SHOWING POSITION OF HATCHING TKAYS, DAM, £TC. 



Hatching-troughs, Guard-screen, etc. 



Hatching trays (C), made about twice as long as wide, i. e., 28 by 

 13^, are convenient to baudle and adjust in the troughs. The sides 

 of the frame are made of good pine lumber, dressed, 1 inch square; 

 the ends are dressed A by 1 inch, and are cut into \\\& sides to form a 

 smooth surface on the bottom for the wire filling. The wire used on 

 the trays is woven with 8 threads to the inch, with a mesh § inch long, 

 and should be well galvanized after it is woven, in order to prevent 

 rusting at the laps. 



