PONDS. 35 



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 clean. 



The box can be so arranged that the rollers also can be re- 

 moved each season ; and this arrangement on various accounts 

 is much the best. 



This box looks, at first sight, somewhat complicated, 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 lum- 

 ber 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 follows : Let us 

 compare a double row of forty Ainsworth Screens, each two feet 

 square and occupying a space in the raceway forty feet long and 

 four feet wide, with one of the new spawning boxes of the same 

 dimensions. 



ist. By the old way it would take two men a good half-day to 

 remove the screens singly, feather off the eggs in a careful man- 

 ner, and return each (double) screen to its proper place. 



It would take the new spawning box about fifteen minutes to 

 do the same work with one man. 



2d. The weight of the gravel which has to be lifted in the old 

 way every time the eggs are removed amounts to many tons in 

 the course of a season. 



In the new box the gravel is not lifted at all. 



3d. By the old way the operator's hands must of necessity be 

 more or less wet during the whole operation. Now, as the trout 

 and salmon spawn during the winter season, when the thermom- 

 eter generally stands below the freezing-point, taking eggs in the 

 old way is not only inconvenient and painful, but often impos- 

 sible. 



By the new way the hands are not made wet, and may be kept 

 comfortably gloved. 



