90 KEPORT OF COMMISSIONER OF FISH AND FISHERIES. [88] 



THE DREDGE. 



The dredge in ordinary use on shipboard, Plate XLIX, Fig. 1, is 

 composed of two jaws or month pieces, flaring about 12 degrees, and 

 joined together by an iron stud at each end, which is welded to the 

 jaws. The net is laced through holes along the back of the mouth- 

 pieces, and is protected from chafing on the bottom by a canvas shield 

 drawn over it and laced through the same holes. 



Short iron arms serve as a bridle, one being a few iuches longer than 

 the other and secured to it by a seizing, which is intended to part when- 

 ever undue strain is brought upon it and allow the dredge to be drawn 

 up end on, in which position it would be most likely to free itself from 

 an obstruction. The dredge used ou board the Albatross is of the fol- 

 lowing dimensions : 



Jaws : 



Length, 2 feet. 



Width, 2i inches. 



Opening between, 8 inches. 



Angle of, 12 degrees. 

 Stud: 



Length, 6 inches. 



Diameter, round iron, f inch. 

 Bridle : 



Diameter, round iron, f inch. 



Weight of metal part, 26 pounds. 

 Net: 



Length, 3 feet 6 inches. 



Size of mesh, square, 1 inch. 



Material, cotton, barked, 30-thread. 



Jacket, length, 2 feet 6 inches. 



Jacket, size of mesh, -J- inch. 



Jacket material, cotton, barked, 16-thread. 



Bottom lining, cheese-cloth. 

 Shield, length, 3 feet 8 inches. 

 Shield, material, No. 2 cotton canvas. 



The dredge described above, having its jaws set at an angle, is in- 

 clined to plow the bottom, and, where the latter is soft, bury itself 

 beneath the surface. This is a necessary feature on a hard sandy 

 bottom, but in the soft ooze of the deep sea it is a serious detriment. 

 Various devises were resorted to by Lieutenant-Commander Sigsbee on 

 board the Blake, and finally the following form was adopted and 

 called the " Improved dredge." It is known here as the " Blake 

 dredge," and will be referred to under that name, Plate XLIX, Figs. 3 

 and 4. 



The following description is from Sigsbee's Deep-sea Sounding and 

 Dredging: 



" By reason of having flaring mouth pieces and a flexible body com- 

 posed of the bag and shield, the old pattern dredge is almost sure to 



