UNITED STATES, FISH-CULTURE IN THE. 



805 



carried upward along the sides, thence inward 

 toward the center, from which point they 



again sink to the bottom. The current is regu- another device for securing the same ends was 



the greatest advantages derived from the Hoi- 

 ton hatcher was economy of space. In 1874 



lated to give the desired motion to the eggs. 

 With heavy eggs like those of the salmon there 

 is no motion, but the water coining from be- 

 neath tends to buoy the eggs upward, thus 

 preventing any injurious pressure on the lower 

 ones by the mass above. The outflow-pipe is 

 movable, and can be lowered to a point where 

 the dead eggs, which are lighter than the good 

 ones, come in con- 

 tact with it and 

 are carried off. 

 By this means the 

 eggs are kept 

 comparatively 

 free from the in- 

 jurious effects of 

 fungous growth or 

 decaying eggs. 1 ' 

 The jar is fifteen 

 inches high, six 

 inches in diam- 

 eter, and has a 

 capacity of five 

 quarts. It ; ' can 

 be filled two 

 thirds full of eggs 



with very satisfactory -results ; 60,000 shad- 

 eggs are considered a fair quantity." 



For the hatching of heavy eggs, almost any 

 device will answer. The early forms of boxes 

 were perforated for the entrance of water, sup- 

 plied with gravel to cover the bottom, and on 

 this the eggs were deposited ; the boxes were 

 placed in running water, and hatching pro- 

 ceeded with little difficulty. Later, parallel 

 glass tubes, or grilles, were substituted. for the 

 gravel. A very good invention for hatching 

 heavy eggs in layers was the Holton box, pat- 

 ented March 18, 1873, in which the eggs in 



patented by Mr. N. W. Clark, of Clarkston, 

 Mich. The Clark hatching-trough is divided 

 into ten to twenty compartments, each 15 

 inches long, 12 inches wide, and 12 im-lu-s 

 deep, inside measurement; the divisions are 

 made by water-tight partitions or bulkheads. 

 Each compartment contains a box in which is 

 placed a series of trays filled with eggs and 



COSTE'S THAT. 



single layers were received upon trays placed 

 one above another ; the current of water, en- 

 tering from below, passed through each tray 

 and escaped at the top. This was one of the 

 earliest forms of apparatus by which an upward 

 current of water is utilized, such apparatus 

 marking a decided advance in the art. One of 



SIB JAMBS MAITLAND'S HOWIETOTTN HATCHERY. 



covered with a pan of perforated tin upon 

 which the water falls, to descend upon the eggs 

 in the trays beneath, escaping at the bottom, 

 and then passing up around the sides and ends 

 of the box on its waj to the second compart- 

 ment. All of the water passes through each 

 compartment before it escapes through the 

 waste-way at the end of the trough. This was 

 intended more especially for white-fish, but is 

 used for all salmonoids. The Williamson or Cali- 

 fornia box is similar to the Clark box, but the 

 water is introduced from below instead of above. 

 This form is now extensively used in Ger- 

 many. In 1874 Mr. Livingston Stone de- 

 signed an apparatus for hatching salmon- 

 eggs in bulk by suspending from frames, 

 in a Williamson trough, wire baskets con- 

 taining the eggs. The compartments are 

 separated by double partitions, the first 

 reaching to the bottom and the second 

 raised a little from it. The water falls 

 over the first partition and passes under 

 the second into the compartment, upward 

 through the basket of eggs and out over 

 the next partition. Mr. Stone often placed 

 12 to 15 layers of eggs in a basket without 

 injuring them. One modification of the 

 Holton system is the Ferguson jar, a cy- 

 lindrical jar of glass containing wire-cloth 

 egg-trays and having, a circular opening 

 to admit water at the bottom and a simi- 

 lar one at the top for the outflow. This j.-ir 

 was patented in 1876. Before the Ferguson 

 jar came Chase's hatching-jar, a cylindrical 

 jar of glass with a metal rim notched at one 

 side, and furnished with a screen to prevent 

 the escape of the fish. In this Excellent jar 



