COMMON TROUT. 89 



" 6. If you think fit to give the young fish more air than 

 what enters at the two brass grates, you may have in each 

 cover a hole made of the same size, and guarded with a brass- 

 wire grate, as 3 ; and for the same reasons, I have done this 

 out of precaution, but have found it, in the end, to be unne- 

 cessary. 



" SECTION II. 



" 1. Spring water out of rocks or stony ground is the 

 properest for breeding of Trout and Salmon ; but where it is 

 not to be had, other spring water may do, provided the cur- 

 rent is strong enough, so as not to freeze in hard frosty 

 weather. 



" 2. If the spring has not fall enough, you must raise 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 first grate in the opening, on the head part of 

 the trough, Section I. 2, of one square inch diameter, and 

 determine its length at least two inches above the grate ; 

 the remaining water from the spring can be led off sideways. 



" If you have an inclination for more breeding troughs 

 than one, they should be fixed in the same direction as the 

 first, and a larger pipe must be placed to the head of the 

 spring, which must empty itself into smaller pipes, laid across 

 the water troughs, so that each trough may have its proper 

 quantity of water conveyed into it ; or it may be managed by 

 means of brass cocks ; but this is left to the choice of every 

 one's own pleasure, as the most convenient method will be 

 soon found out. 



" 3. After the box or trough is properly finished, it must 

 be placed horizontally upon two legs of wood, stone, or 

 brick ; and within upon its bottom put some clean washed 

 gravel, about the size of peas and beans, two inches high ; 

 afterwards sprinkle some coarse gravel or pebbles over it, the 



