. Bulletin of the Bureau of Fisheries. Fisheries; Fish culture. DEVICES FOR USE IN FISH HATCHERIES AND AQUARIA. 1029 Water A SIPHOID OUTLET FOR HATCHING AND REARING TROUGHS. The various systems of outlet in most fish-cultvu'al equipment are defective in several ways, as I have had occasion to observe on visits to different estab- lishments. The young fish escape in the outflow, perhaps, due to its faulty construction or installation; many of them are caught in the perforations of the sheet-iron cap and die there; many others are killed or injured by the fingers that try to rescue them; overflo
. Bulletin of the Bureau of Fisheries. Fisheries; Fish culture. DEVICES FOR USE IN FISH HATCHERIES AND AQUARIA. 1029 Water A SIPHOID OUTLET FOR HATCHING AND REARING TROUGHS. The various systems of outlet in most fish-cultvu'al equipment are defective in several ways, as I have had occasion to observe on visits to different estab- lishments. The young fish escape in the outflow, perhaps, due to its faulty construction or installation; many of them are caught in the perforations of the sheet-iron cap and die there; many others are killed or injured by the fingers that try to rescue them; overflows are caused by the clogging of the perforations; the water is not thoroughly re- newed and the trough becomes infected with germs of disease. All this is too familiar to need to be dwelt upon. I have sought to overcome various difficulties by the following device. I have provided a large cylin- drical wire screen or cage, which is set over the outlet and incloses the outlet apparatus which I shall de- scribe. The large surface of the screen gives free course to the water without attracting the yoimg fish and thus becoming a means of their destruction. In the daily procedure of changing the water in the rearing troughs, I desire to be able to lower the level to a given point without the necessity of losihg time waiting beside the trough. To accomplish this I have made, first, for the orifice in the bottom of the trough, a water-tight collar of two pieces screwed together with a leather washer between. The lower piece is supplied with lugs extend- ing downward, and into this collar is inserted a tube, making an ordinary standpipe. With this form of outlet, however, the water is renewed only at the surface, the bottom water, with remnants of food, refuse substances, etc., being left unchanged. I have accordingly elaborated the standpipe into a form which constitutes an unfailing cleaning device. It carries off all the solid matter. Fig. 2.—A siphoid outlet for hatching and rea
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectfisheries, bookyear19
