GRAVEL FOR BOXES. 87 



gravel pit, sift it tlirougb a sieve — the meshes 

 of which are half an inch — and when you 

 have enough sifted, boil it for an hour or so 

 in a copper till it is quite clean. The boiling- 

 destroys the sporules of the vegetation, and 

 also the eggs of the minor water beasts that 

 eat the spawn. Then get the mason or the 

 carpenter to fix the boxes in the stream, or 

 better do it yourself; get the levels right by 

 means of bricks, wedges of wood, &c., and 

 then wheel down the gravel to the place ; 

 then, with a spade, carefully deposit in the 

 boxes your boiled half-inch sized gravel, to 

 the depth of about two or more inches. You 

 must then place a layer of about one inch in 

 thickness, or one and a half, of gravel stones 

 — take them as they come — each stone being 

 about the size of a walnut. The reason of 



