132 



FISH FARMING ! 



pendently of the others. This plug should be of not less than 

 lin. diameter, aind IJin. is a safer size. The direction of the 

 current is shown by the arrows. A long slat floated between 

 the two rows of trays will keep them, in better " line/' and is 



A HATCHING TRAY. 



advisably added. The boxes should be fitted with wood 

 covers, which should always be in position during incubation, 

 excepting, of course, when the eggs are being looked over and 

 attended to. 



Fig 33. Plan of Hatching Box. 



The hatching trays are far and away the simplest and bsst 

 I know of. They are made of two wooden ' 7 boat-shaped " 

 sides, and to the curved, edges of these is fastened a strip of 

 perforated zinc. The traiys are similar in shape to a " swing- 



Fig. 34. Longitudinal Section of Hatching Box. 



boat." In Fig. 35 I have imagined that one can see through 

 the front side of the tray. A is the wooden side ; B B B the 

 atrip of perforated zinc, which forms the bottom and ends 

 of the tray all in one; c c are handles fitted across the top of 



