[3] SHAU-HATCHING OPERATIONS AT NAVY-YARD STATION. 893 



of each net being $60 a mouth. They require three men and a boat to 

 teud each net, ueeding great attention, as any sudden rise in the river 

 may wash them away, unless they are hauled up clear of the water. 

 Pound nets this season caught an unusually small number of fish, espe- 

 cially shad, which fishermen ascribe to the prevailing muddy water and 

 freshets. 



Several attempts have been made to hatch herring at this station, but 

 with unfavorable results. When the spawn was taken the temperature 

 of the water was so low as to retard their development. On one occa- 

 sion 3,000,000 herring eggs were obtained, the cold water killing the 

 young fish as soon as hatched. 



The jar invented by Col. Marshall McDonald has been used with suc- 

 cess on several occasions, the period of hatching being the same as the 

 cones. The eggs taken after the 1st of June turned out badly, a large 

 number of females being found, but no males, so that it was impossible 

 to impregnate the eggs. 



The fishing season this year has been unfavorable, owing to the causes 

 previously mentioned, a low temperature of the water and successive 

 freshets. 



From the market reports of Washington the following information 

 has been gathered in regard to the total catch of shad and herring in 

 the Potomac for 1881 and 1882, to the Ist of June inclusive : 



The following is a recapitulation of the work done from April 19 to 

 June 8, 1882, on which day the station was closed : 



Total number of shad eggs received 21, 820, 000 



Total number of shad fry hatched 17, 935, 000 



The per cent, being 82. 19 



There have been 3,050,000 shad fry put into the Eastern Branch of 

 the Potomac at thisstationj 1,710,000 into the Potomac at Little Falls; 

 the remainder, 13,175,000, being sent to the Central Station for distribu- 

 tion. 



Accompanying the report is the daily journal kept at the station: A 

 form containing the meteorological observations taken three times daily; 

 a form containing the record kept by the spawn-takers stationed at 

 Moxley's Point. 



The apparatus designed by me to operate hatching cylinders by means 

 of any small stream of water with slight fall was develoj)ed and put in 



