880 KEPORT OF COMMISSIONER OF FISH AND FISHERIES. [2] 



eiiing a public interest in the work and in greatly cheapening the cost 

 of distribution. 



In obedience to instructions from the Commissioner, I accordingly 

 submitted a programme for the organization, equipment, and conduct 

 of central station for the work of propagation and distribution. It was 

 determined to equip the station with the new hatching apparatus, based 

 upon experiments conducted by me during the season of 1881. (For 

 description of this, see Bulletin of the United States Fish Commission, 

 Vol. Ill, p. 183.) 



The water being drawn directly from the city supply, the available 

 pressure at our command was sufficient to dispense with any arrange- 

 ment for pumping, by which we were enabled to simplify greatly the 

 organization and conduct of the work and reduce the cost of it. 



The proper working of the automatic hatching jars depending upon 

 the delivery of the water through them under a constant pressure, and 

 the ])ressure in the city mains varying from hour to hour and day to day, 

 it was necessary to devise some means to secure a constant head inde- 

 pendent of the varying pressure. This was accomplished by placing 

 upon the second floor of the Armory Building a tank with a capacity of 

 400 gallons of water, into which the water from the city mains was deliv- 

 ered directly, and thence distributed by suitable arrangement of pipes 

 to ten tables occupying a section of the ground floor of the building. 

 By automatic arrangements connected with the tank a constant level of 

 water is maintained in it, and a constant pressure through the jars be- 

 low. The construction of the tank and connecting pipes for supply and 

 distribution is shown in Plate V. The distribution of water to each of 

 the ten tables and the general arrangement of the interior of the hatch- 

 ing station is shown in Plate I. Each table is 15 feet long, 3 feet wide, 

 and 39 inches high, this unusual height being given for convenience in 

 observing and manipulating the jars. In the center of each table and 

 extending nearly the entire length of it is a watertight trough covered 

 by a grating. The bottom of this trough has a slight inclination from 

 one end to the other, and delivers the water collected from the discharge 

 through the hatching jars into a waste pipe, which empties it all into the 

 sewerage from the building. Each table can conveniently accommodate 

 thirty jars, having each a capacity of 100,000 eggs, giving a total capac- 

 ity to the station at one time of 30,000,000 eggs, and for the season of 

 upwards of 200,000,000. This capacity can be increased to any extent 

 desired. 



In order to arrive definitely at accurate estimates of the number of 

 eggs manipulated, and to determine the percentage of loss during incu- 

 bation, a scale is employed, each division of which represents 10,000 

 eggs. By the application of this to the side of the jar, the eggs being- 

 allowed to subside to the bottom, the number of eggs contained in each 

 can be read off accurately. An observation of this kind being made 

 when the eggs are first placed in the jar, and a similar observation re- 



