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plan " a race is first made containing a single row of Ainsworth 

 screens ; a parallel race of the same length is made bj its side. This 

 is a blind race, or one into which the fish cannot enter. The upper 

 screens in the first race are made stationary, and the under screens 

 are so placed on slides that thej can be reached from the parallel race 

 and drawn out into it. This arrangement does away with the removal 

 of the upper screen, the displacement of gravel, driving away the fish, 

 saves some time, and is so far an improvement. But it does not 

 obviate the other diflicnlties. There is still too much working in cold 

 water and too much time taken, and a double race is rendered neces- 

 sary. Another modification of the Ainsworth race is what I should 

 call the hook-and-eye slide. The upper screens are made stationary, 

 as in the former case. Cleats for the under screens are made along 

 the whole length of the race. The under screens are made as usual, 

 except that two hooks are fastened into one side and two eyes into 

 the opposite side. Then tlie operator, standing at either end of the 

 race, slides in one of the under screens, placing the eyes toward him. 

 Taking another screen, he fits its two hooks into the eyes of the first. 

 The second screen puslies the first further in, and so on to the end. 

 When the race is to be drawn, the first screen is pulled out its full 

 lengtli, unhooked, and the eggs are taken. The second is thus 

 brought into reach, pulled out, unhooked, etc. This race takes up 

 less room than the former ; but its screens are also ten or twelve 

 inches under water, and the contrivance, like the other, is clumsy, 

 unhandy, and requires too much labor. The otlier modification of 

 the Ainsworth race is my own patent roller screen. This has been 

 in use for three years at our establishment ( Seth Green and A. S. 

 Collins, at Caledonia, N. Y.), and we still think it the best thing for 

 the purpose. In tliis contrivance the race should be made about four 

 feet wide and thirty feet long. The upper screens, instead of being 

 made single, are made in sections of any convenient size. A roller is 

 fixed in each end of the box, under the upper screens, and, instead of 

 under screens, an endless apron of wire-cloth is made to pass over the 

 rollers the whole length and width of the race. An apron, twenty- 

 five or thirty feet long, would be liable to sag in the middle, but cross 

 pieces are fastened to it, which slide upon elects nailed to the side of 

 the box, and the whole upper side of the apron is kept at a distance of 

 one inch from the upper screen. Two cog-wheels are connected with 

 one of the rollers, by means of which it can be turned from above 

 with a common crank handle ; and also a tin pan, four inches wide 

 and four feet long, or better, four pans of a foot each, set into a light 



