79-f OYSTERS, AND ALL ABOUT THEM. 



possible, was supplemented by dredging lines run by the 

 schooner. Traverses were made as with the boats, and 

 observations for ascertaining the character of the bottom, 

 both of the surface and substrata, observations of tempera- 

 ture, and the selection of the various specimens, were 

 carried on. 



The position of the vessel, however, was more fre- 

 quently ascertained than had been customary in the boat 

 work. The lowest possible rate of speed was maintained 

 that was consistent with safe and ready manceuvering (a 

 matter of some difficulty), and the dredge put over at 

 intervals varying from two to ten minutes, and depending 

 upon the character and extent of the bed, depth of water, 

 and ability of the crew to get the dredge in, it being at 

 times necessary to heave the vessel to in order to recover 

 it. 



The dredge was put over from the weather side, and, 

 after having dragged a sufficient distance to insure its 

 bringing up a specimen, should there be any oysters, was 

 hauled in by hand. The presence of oysters on the bottom 

 was readily detected by placing the hand on the dredging 

 rope, the uneven, jumping motion of the dredge as it 

 gathered the oysters and shells being distinctly perceptible. 



The dredge was usually on the bottom from thirty to 

 forty-five seconds, which length of time was sufficient for 

 our purpose and sometimes enough to fill the dredge, a 

 catastrophe which was not desirable. Soundings were 

 taken along the lines, and, with the character of the bottom, 

 recorded. 



The following form for keeping the record was used 

 and found to be of great value. 



