SALMON FISHERY. I2i 



muft be fattened behind with ftrong hinges, and 

 before with handles, to lift them conveniently up 

 by ; and as the boards are apt to warp, on account 

 of the water within, and the air without, it is re- 

 quifite to have each clamped with two or three 

 crofs pieces. 



6. If you think fit to give the young fifh more 

 air than what enters at the two brafs grates, you 

 may have in each cover a hole made of the fame 

 fize, and guarded with a brafs-wire grate ; this, 

 however, has been found, after repeated obfer- 

 vations, to be unneceffary. 



7. Spring water, out of rocks or ftony ground, 

 is the propereft for breeding of trout and falmon ; 

 but, where it is not to be had, any other fpring 

 water may do, provided the current be ftrong 

 enough, fo as not to freeze in hard frofty. weather. 



8. If the fpring has not fall enough, you muft 

 raife a dam around it, one or two feet higher than 

 the top of your trough ; convey the water from 

 thence through a pipe or gutter, to the firft grate 

 in the opening, on the head part of the trough, of 

 one decimal fquare inch diameter, and determine 

 its length at leaft two inches above the grate ; the 

 remaining water from the fpring can be led off 

 fide-ways. 



If you have an inclination for more breeding 

 troughs than one, they fhould be fixed in the fame 

 dire&ion as the firft, and a larger pipe muft be 

 placed to the head of the fpring, which muft empty 

 itfelf into finaller pipes, laid acrofs the water- 

 troughs, 



