472 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [36] 



23. DREDGE. 



The dredge used on the Grampus is the ordinary type employed by 

 naturalists, a pattern which was long since adopted in Europe and 

 America. It is of the size commonly called " boat dredge," being smaller 

 than the " ship's dredge," from which it differs only in dimensions. It 

 is composed of an iron frame to which is attached a net bag, the latter 

 being covered by a bottomless canvas shield to protect the net from in- 

 jury by chafing on the sea bottom when being towed. 



The frame consists of two jaws joined together by an iron stud at each 

 end, which is welded to the jaws, the latter being so arranged that they 

 flare at an angle of about 12 degrees. 



The frame is 18 inches in length, 5J inches inside, and 7J inches be- 

 tween the edges. The jaws are 2J inches wide and one-half inch thick ; 

 the bridles are 16 inches long. 



The net is 2£ feet long, has 2 or 3 meshes to the linear inch, and is 

 closed at the lower end, so that it is approximately conical in form. 

 The net is fastened to the iron frame by a lacing that passes through a 

 series of holes in the back of the jaws. The canvas shield which pro- 

 tects the net from chafing is laced through the same holes. 



The towing-line is bent to one of the bridles only, the other bridle 

 being held by a smaller piece of line, or by a seizing, to the tow-rope or 

 the bridle it is fastened to. This arrangement is necessary to prevent 

 the loss of the apparatus when it comes in contact with stones or other 

 obstructions on the bottom, since the seizing will break under a heavy 

 strain and thus allow the dredge to be pulled up end on, in which posi- 

 tion it is most liable to free itself. 



24. "GRAMPUS" TOWING-NET. (See fig, 4.) 



The large surface towing-net used on board of the Grampus was de- 

 vised by the writer with the object of securing an apparatus which 

 would be convenient to stow away on board the vessel, and one which 

 would also prevent the escape of such animals as entered it. It con- 

 sists of a hoop-shaped frame made of g-inch iron, jointed in the middle 

 so that it may be folded together for convenience in stowage. The 

 diameter of the hoop is 5 feet. The net, the mouth of which is laced 

 to the hoop by a roving, is cone-shaped, with an interior funnel-shaped 

 net that forms a pocket at the lower end for preventing the escape of 

 such animals as enter the apparatus. The lower end of the net is 9 

 inches broad when open, and is so arranged that it can be tied up with 

 a string that passes through the meshes on the border, and is intended to 

 be unloosed to let out the contents. The mesh of the net is f-inch, 

 stretch measure, next the hoop, tapering to J-inch at the lower end or 

 apex of the cone. The two lower rows of meshes are made of heavy 

 twine to stand the strain of being tied up. When in use a rope bridle 

 is attached to the hoop with a thimble in the center for the towing- 

 rope to bend into. 



