PRACTICAL FISH-CULTURE. 585 



By my i)laii of confining tlie fish, wlien hatclied, to the boxes wherein 

 they are hatched, they can never escape into the troughs, and, conse- 

 quently, cannot get into the current through the waste-ways and choke 

 the screens. The passage of the water down through the boxes is so 

 broad, being the full size of the interior of the boxes, that the fish are 

 not carried or forced downward, but they rise naturally, and these 

 screens h are placed, as described, to prevent the fish from passing up 

 the current. 



What I claim as my invention, and desire to secure by letters-patent, 

 is — 



1. A fish hatching house, wherein the water-tank B, hatching-troughs 

 C, hatching-boxes D, cleaning-trough H, and water-ways h are con- 

 structed and arranged with relation to each other, substantially as and 

 for the purposes herein set forth. 



2. In combination with any suitable troughs, C, the hatching-boxes D, 

 provided with feet, c, gauze-bottom sieves, E, and a perforated pan-cover, 

 F, arranged to receive the water in the pan on top and discharge it be- 

 low, substantially as and for the purposes specified. 



3. The cross-bar G, constructed as described, in combination with 

 the troughs C and hatching-boxes D, for the purposes set forth. 



4. In combination with hatching-boxes, the perforated pan-cover F, as 

 described, and for the purposes set forth. 



NELSON W. CLARK. 

 Witnesses : 



C. E. B. HuESTis. 

 H. S. Sprague. 



Williamsoti's hatching -box. — [From the California Mining and Scientific 

 Press, February 28, 1874. 



To those persons engaged in fish-culture on a large scale, an improve 

 ment in hatching-boxes, recently perfected by Mr. John Williamson, sec- 

 retary of the California Acclimatizing Society, will be of interest. We 

 give an engraving of this box, which possesses some peculiar features. 

 Mr. Williamson calls it the improved double-riffie hatching-box. Its spe- 

 cial features can easily be seen by reference to the cuts. The upper figure 

 shows a trough with light hatching-boxes, and the lower figure is a sec- 

 tion of the box one-quarter of the full size. The usual way of arranging 

 these hatching-boxes is to place the eggs on the bottom, and allow the 

 water to flow over them. A box, the same size as the one represented, 

 will then hold 20,000 eggs. Mr. Williamson puts in the box five trays 

 19^ inches long and 18 inches wide, with a frame three-quarters of an 

 inch thick and one inch wide, with a wire bottom having eight squares to 

 the inch. By this means, he has space to hatch 120,000 eggs, where he 

 only had before, in the same box, space to hatch 20,000 eggs. This is 

 of great importance in hatching-bouses where room is desirable. The 



