72 PRACTICAL TROUT CULTURE. 



and always leaving it uppermost. This apron is 

 fastened around the rollers by a lacing of cord. 

 At the end of the season the water in the pond can 

 be drawn down a foot and everything taken out 

 but the rollers. Give the screens a coat of paint or 

 gas tar, and lay them away in a dry place until 

 the next autumn. A stiff brush may also be placed 

 under the forward roller, so that every time the 

 roller is turned to remove the eggs, the screen will 

 be perfectly cleaned. 



The box can be so arranged that the rollers also 

 can be removed each season, but as this involves 

 extra trouble and expense, and as the axles of the 

 rollers and even the cog-wheels can be made of 

 hard wood (little strain coming upon them), we 

 generally leave the rollers in through the season. 



This box looks at first sight somewhat compli- 

 cated, but is in reality very simple and easier to 

 make than to describe. Any one who has the 

 knack of using tools can make one which will 

 answer the purpose perfectly. The cost is very 

 little more than that of the Ainsworth screens (of 

 the same area) as generally used. The cost for 

 wire being the same in both cases, the lumber in 

 the box itself being extra, and also the rollers, 

 hinges, and cog-wheels (or windlass wheel). 



A few of the advantages of the plan are as fol- 

 lows : Let us compare a double row of forty Ains- 



