MANUAL OF FISH-CULTURE. 151 



the metal plate, admits the glass tube whicli carries off the waste 

 water. The central tube is couuected by half-inch rubber tubing with 

 the pet-cock, which regulates the supply of water. A groove iu the 

 inner surface of the metallic plate carries a rubber collar, and when 

 the plate is in place the tightening of the metallic screw-cap seals the 

 opening hermeticall3^ Both the inlet and outlet tubes pass through 

 stuffing-boxes provided with gum-washers and binding-screws. The 

 central or feed tube is provided with stuffing-boxes, one on the top of 

 the disk and one on the bottom, the better to hold it to a true center. 

 The outlet tube is provided with only one stuffing-box, and the binding- 

 ring is beveled. 



In j)reparing the jar for work the side tube is fitted first. The glass 

 tube should be wet, the gum-washer slipped on the tube about an inch 

 from the end and introduced into the opening. Holding the tube per- 

 pendicularly to the face of the plate, press fairly on the tube, and the 

 washer, rolling on itself, will fall into the seat provided for it. Screw 

 on the binding- g .^^.....,.,,.^.., , — — — ^ 

 ring, and test by 

 seeing that the 

 tube slides freely 

 back and forth in 

 the stuffing-box; 

 if not, it should 

 be refitted with a 

 heavier or lighter 

 washer, as maybe 

 required. Glass 

 tubes can not be 

 procured of abso- 

 lute uniformity in Egg Funnel. 

 size. Water is the only lubricant that should be used about the jar 

 fittings. 



The jar, after being washed clean, is filled with fresh water. A 

 shallow tin funnel witli a perforated rim is inserted, so that the water 

 will stand as high in the funnel-throat as j)ossible, and the eggs are 

 poured iu by dipperfuls, or when taken from transportation trays are 

 washed in by a jet of water. Care is used to have the eggs fall but a 

 short distance, and no fish scales or other foreign matter should enter 

 the jar with them, as the presence of anything but water and eggs ren- 

 ders a proper motion of the mass impossible, and usually results in the 

 loss of a large proportion of the eggs. The requisite number of eggs, 

 80,000 to 100,000, being in the jar, it is put in position and closed, 

 care being taken that both the inlet and outlet tubes slide freely in 

 their stuffing-boxes. If the tubes become gummed, let water trickie 

 down around the bicding-screws. To close the jar, turn on the water, 

 place the feed-tube in the jar, turning off the water immediately after 

 the feed-tube has passed beneath the surface of the water in the jar, 



