PEACTICAL FISH-CULTURE. 579 



most important, Setli Green's box,* (PI. XVII, Figs. 1 & 2,) patented, 

 which has been longer and much more extensively used than any other. 

 It is an ordinary box, made of inch-boards, and covered on the bottom 

 with wire-cloth painted with coal-tar or naphtha varnish, and with two 

 cleats made of scantling nailed obliquely to the sides of the box, which 

 act as floats; these incline the box so that it stands with the bottom pre- 

 sented toward the current at an angle of about 60° in an ordinary tide- 

 current, creating a slight but sufficient circulation of the water in the 

 box to keep the eggs from lying entirely inert at the bottom. Six or 

 more boxes are tied together in a string or gang, and anchored a short 

 distance from the shore. 



Bracl-eWs box. — Another box patented, used by Mr. Brackett for the 

 first time in 1873, is arranged to float horizontally in the water ; the end 

 presented to the current sloping inward and backward, so that the bot- 

 tom of the box is of less length than the top. A circulation is produced 

 by the downward deflection of the current, which creates an eddy directly 

 beneath the wire-cloth bottom of sufficient strength to agitate the water 

 and the eggs within the box. 



Stilwell and Atldns\^ box. — Another plan has been suggested by Mr. E. 

 M. Stilwell, fish-commissioner of Maine, and Mr. Charles G. Atkins, of 



'^ Device for hatching the spawn of fishes. — United States Patent-Office. — Seth Green, of 

 Rochester, New York. — Letters-patent No. 68871, dated September 17, 1867. 



(The schedule referred to in these letters-patent and making part of the same.) 



To aM whom it may concern: 



Be it known that I, Seth Green, of Rochester, in the county of Monroe, and State of 

 New York, liave invented a new and useful " method of hatching fish-spawn ;" and I 

 do hereby declare that the following is a full, clear, and exact description thereof, 

 reference being had to the accompanying drawing, making part of this specification 

 in which the figure is a vertical central section of my invention, represented as ap- 

 plied in the water. 



This invention relates more especially to the propagation of shad, and its nature 

 consists in the peculiar construction and arrangement of a propagating or fish or frog- 

 spawn hatching-chamber in such a manner as to effect a perfect and uniform circula- 

 tion throughout the entire chamber, and at the same time prevent the escape of the 

 spawn, and also of the young fish, until the attendant thinks proper. 



To enable others to make and use my invention, I will describe its construction and 

 operation. 



I provide a rectangular box. A, of any desired size or proportion. I prefer them, 

 however, about two feet long by eighteen inches wide and ten or twelve inches deep. 

 I provide a suitable square opening in one end, as shown at B. This opening is covered 

 upon the inside of the chamber with a fine wire screen, about No. 12, and upon the 

 outside is hung a cap, C, which may be pivoted above, as shown, and made to swing 

 down over the opening, or it maybe made to slide over it horizontally. I also provide 

 the open bottom with a similar wire screen, D, but of finer mesh. I attach a shallow 

 frame, F, to the lower edge of the chamber or case A, outside of the screen. There may 

 be one or more cross-bars, E, but they should be made thin on the upper side as shown, 

 to ijreveut the lodgment of any of the sjiawn upon them, as the spawn will only hatch 

 well when buoyed up in the water by a perfect circulation. I attach a float-bar, G, 

 obliquely across each side of the case or chamber A, and to one end of these I attach a 



