THE HISTORY OF FISH CULTURE. 547 



iieath, passing tbroiigli all and escaping at the bobtom, afterward flow- 

 ing over the partition upon the cover of the next box, and so through- 

 out the series of compartments until it escapes through the waste-way 

 at the end of the trough.* 



By this arrangement a very small quantity of w^ater is required for a 

 very large number of eggs, and all the advantages of handling and 

 removal of sediment and considerable economy of space are atibrded. 



Another combination of the trough and tray methods is in use in Cal- 

 ifornia, devised by Mr. John Williamson, of the California Acclimatizing 

 Society. This is very similar to the one just described, except that the 

 flow of water through the screens and eggs is from below instead of 

 from the top. This model was not the result of work in white-fish hatch- 

 ing, as in the case with the two first mentioned. 



An experiment was made by Mr. N. W. Clark in the hatching of white- 

 fish eggs, which were laid in singlelayers of woolen cloth stretched on 

 very thin frames of wood, packed in a box imbedded in sphagnum moss 

 within a refrigerator and the whole kept at a temperature a little above 

 the freezing-point by ice. The eggs are left entirely undisturbed after 

 they are first arranged, and the only care on the part of the attendant 

 is to keep the temperature above the freezing-point. The presence of 

 dead eggs does not seem to contaminate the living ones in.this condition, 

 and very little coufervoid growth appears. A quantity of eggs carried 

 forward in this manner through the winter api)eared to be in excellent 

 condition, development progressing slowly, and a few taken from the 

 cloths and placed in spring-water hatched out within a short time as 

 well-developed embryos. If this method, after full and thorough 

 trial, should prove successful, it would make the work of hatching a 

 matter of neither effort, care, or expense. It has been a matter of too 

 short experience and of experiment on too small a scale to warrant its 

 positive success. 



An improved case for the carriage of eggs long distances by railroad 

 is another device perfected by Mr. N. W". Clark in 1872. It is a modifi- 

 cation of the ordinary case containing circular cups, the cups being 

 square, and in this form economizing space very much. The cups of 

 tinned iron, about four inches square and two inches high, rest in trays, 

 with low partitions forming low compartments that retain the bottom 

 of each cup and hold it solidly in place. The trays are set within a 

 square tin box, in which they fit with moderate tightness, and are 

 placed, when containing the cups, eight or ten in the box, one above the 

 other ; this box is set within another box of tin large enough to leave 

 an open space on all sides, to be filled with sawdust ; a tube is inserted 

 through the bottom of the inner box, piercing the bottom of the outer 

 one, so as to permit communication with the air on the outside; the 

 whole is then placed for protection within a strong wooden box, in the 

 bottom of which is a frame resting upon stiff" springs which relieve the 

 * For full description see i)late and explanation. 



