258 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Capt. Dannevig's has now been completed. The establishment may be described 

 under the following heads: (1) the hatchery house; (2) the spawning pond; (3) the 

 filtering gallery; (4) the tidal pond; (5) the pumping apparatus. 



The hatching house consists of a substantial and ornamental wooden building 35 

 feet in length, 24 feet broad, and 18 feet in height. The walls, which are double, 

 stand upon a foundation of brick and concrete, a space of 2 feet being left between 

 the flooring and the ground for the circulation of air and the convenience of piping. 

 As abundance of light is desirable, there are 12 large windows in the sides and gables 

 and a door is placed at either end. At present 16 of Dannevig's hatching apparatus 

 are fitted up, each capable of containing about 5,000,000 of cod eggs, or a total of 

 about 80,000,000. 



The apparatus consists of an oblong wooden box, 8 feet in length, 2 feet 3 inches 

 in breadth, and 1 foot deep. It is divided into two series of 7 water-tight compart- 

 ments by one central longitudinal and G transverse partitions, making altogether 14 

 compartments. The first and last compartments in each series — those at the etuis — 

 are narrow and communicate with one another, the pair at one end receiving the 

 water from the inflow pipe, and the pair at the other end communicating with the 

 outflow pipe. The intervening ten compartments are wider, and it is into these that 

 the hatching boxes which contain the eggs are placed. 



Each hatching box is 12 inches long, 10 inches broad and 10 inches deep ; the sides 

 are made of wood, % inch thick, and the bottom of haircloth, fine enough to prevent 

 any eggs from passing out while admitting a free circulation of water. The boxes are 

 attached by leather hinges to the transverse partitions ; and into the top of each par- 

 tition, between the hinges, a broad, flattened metallic spout is inserted, which fits into 

 a corresponding spout attached below it to the edge of the hatching box. The appa- 

 ratus, with its ten boxes, is placed with one end against the end of the room, and 

 rests on wooden supports so arranged that this end is 3 inches higher than the end 

 which projects towards the center of the room, this difference in level giving what 

 experience has shown to be the most suitable flow of water. 



The supply pipes, made of galvanized iron, are led along the walls, a brass cock 

 being inserted above each apparatus. The water falls from the cock into one of the 

 narrow end compartments, which communicate with one another, and when these are 

 full it flows over by the spouts into the first pair of hatching boxes. It passes through 

 the haircloth bottom into the compartments in which the boxes are placed, and when 

 these are full it overflows in turn into the second pair of boxes, and so on until it 

 reaches the narrow end compartments, whence it escapes by a pipe passing through 

 the floor of the room. 



As has been said, tlie hatching boxes are hinged at one side, and as the compart- 

 ment becomes full the fore edge of the box is floated up and ultimately projects about 

 3 inches or so above the surface. This gives occasion for the application of one 

 of the special features of Dannevig's method, namely, an up-and-down movement of 

 the box, by means of which the eggs are kept equally distributed throughout ihe 

 mass of water, as may be shown by testing any part of the box with a dip-tube. The 

 movement is accomplished in the following way: An iron rod, 8 feet long, is hinged 

 at the upper end of the apparatus, next the wall, and passes down the middle between 

 the two series of hatching boxes. It possesses five short, transverse pieces, one 

 opposite each pair of boxes, and resting upon the free edges of the latter; and it is so 



