Ftsh-Hatching in a Current of Water. 107 



the dam, instead of allowing it to overflow at 

 the sluice-gate, and thus, by maintaining a 

 lower temperature in the hatching-boxes, con- 

 tributed greatly to the success of my under- 

 taking. 



The water of this stream is dammed up by 

 a little stone and cement work under a rock, 

 and carried by a two-inch galvanized-iron 

 pipe, which is covered with a hay-rope wound 

 round it to protect it from the sun and to 

 keep down the temperature. The hatching- 

 boxes are seven in number; and in addition 

 to them I had a stone and cement race con- 

 structed on the ground, divided down the 

 centre, and so arranged that the water would 

 circulate with a gentle current through all 

 the boxes, up one side of the race and down 

 the other. There are little miniature water- 

 falls from one box to another, to aerate the 

 water, which finally flows through four small 

 ponds fitted with gratings to retain the young 

 fish, when they are sufficiently advanced to 

 require this precaution, and covered with 

 netting to keep off shags and cormorants. 

 The water of the brook being muddy, I had 

 a very elaborate filtering arrangement erected, 



