ARTIFICIAL PROPAGATION OF SHAD 



479 



number of eggs are in the hatchery a siifiicient amount of water is 

 suppUed through a pump operated by a gasoHne engine. This pump 

 has a 4-inch suction and is connected Avith the main suction line by 

 the use of a tee joint. The suction pipe, of 6-mch galvanized iron, 

 is carried into the river on a pier approximately 170 feet long. The 

 end of the pipe is held some distance from the river bottom and is 

 provided with a protecting screen. At this station the tanks are 

 elevated to a sufficient height to provide a pressure of 8 pounds per 

 square inch at the top of the hatching jars, and each jar rcquu-es 

 approximately 3 quarts of water per minute for its successful opera- 

 tion. 



Scale. 



" 1 



Section A-B 



Fig. 5 Shad-hatching table 



Upper figure shows view from above. 



Lower left-hand figure is an end view showing hatching jar in position. 



Lower right-hand figure shows a cross-section of the drain pipe and trough in center of table. 



In exceptional cases water may be obtained from a municipal 

 water supply, but as such water is frequently sterilized with chlorine 

 or other agents, and as these sterilizing agents have been found, even 

 in very dilute solution, to have a decided toxic effect on the ova, 

 embryos, and young of many fish, such a source of water supply for 

 hatching purposes must be viewed with suspicion. 



The hatching jars are arranged on tables, as sho\\Ti in Figure 5. 

 The tables usually are 16 feet long by 3 feet wide and of an appro- 

 priate height for convenience in the manipulation of the jars. A 

 table of the dimensions given will accommodate 24 jars in a double 

 row — 12 on each side of the rectangular tanks placed in the low 



