PRACTICAL FISH-CULTURE. 581 



To all ivJiom it may concern : 



Be it known that I, Marcelhis G. Holtou, of Rochester, in the county 

 of Monroe, and State of New York, have invented certain improvements 

 in pisciculture or fish-spawn hatching, of which the following is a speci- 

 fication : 



The object of my invention is to provide a simple and convenient 

 method of fish-spawn hatching, which may be practically carried on 

 during the winter-season. Its nature consists, mainly, in the employ- 

 ment, in connection with the spawn-trays, of an upward current or flow 

 of water through the layers of spawn, affording a thorough and con- 

 stant circulation of fresh water through the same. 



In the drawing, (Plate XIV, Figs. 1, 2, and 3,) Fig. 1 is a vertical central 

 section of one case of trays ; Fig. 2 is a top or plan view of the same ; 

 Fig. 3 is a transverse sectional view of the cylindrical bottom B. 



A represents a square box or case, made water-tight, preferably of 

 wood, and provided with a concave bottom, shown at B, or a hopper- 

 bottom might do as well, the object being to cause any sediment, «&c., 

 to be easily removed through the discharge-pipe ])• There is a channel, 

 0, formed entirely around the case near the top. The outer walls of 

 such channel are somewhat elevated above the upper edge of the case 

 proper. This permits a gentle overflow from all sides of the tray-cham- 

 ber, near the bottom of which is fixed a ledge, i, Fig. 1, upon which the 

 trays c may rest. These latter consist of shallow rectangular frames, 

 each provided with a fine wire-gauze bottom, upon which the spawn is 

 deposited and held during the time of hatching. There is a suitable 

 metallic or other strap, s, attached to two opposite sides of the bottom 

 tray in each case of trays, whereby the whole set may be raised or low- 

 ered as may be necessary in removing or replacing them, as hereafter 

 more fully described. There is a vertical recess cut in the sides of the 

 case to receive the straps. The latter are perforated at distances cor- 

 responding to the vertical depth of each tray ; and the straps, if made 

 of metal, may be provided with a suitable pin, a; but if leather is used, 

 they may be hooked upon a fixed pin in the upper edge of the case. A 

 pipe, P, may be used to conduct the water ilrom the spring or fountain 

 into the bottom of the case; or a water-chamber may be formed entirely 

 across that side of the case and also across the bottom. This latter 

 construction is rather preferable for all except the first case in each 

 tier, and, in fact, would not be objectionable for that. To insure a 

 thorough distribution and circulation of the upward-flowing current of 

 water through all parts of the trays, I provide the deflector h, which 

 may be spherical, as shown, flat, or any other suitable shape. It is 

 supported directly over the inlet-opening d upon suitable standards n. 

 The discharge spout or trough / conveys the overflowing water to the 

 descending water channel or chamber of the next succeeding case. 



