EXPLANATION OF PLATES. 
Pratn i: 
The steam trawler ** Nora Niven.” 
Puate II. 
Model of Trawl-net and Otter-boards. 
The model from which the photograph was taken was made by Captain C. 
A. Nielsen, the trawling-master. The ground rope, which sweeps the floor of the 
ocean, is seen to be greatly bowed, but the head line is stretched by the otter- 
boards, so that when the fishes are disturbed by the lower rope they are well: 
covered by the net as it moves forward. Within the small or cod end are two 
pockets which open backwards, so that if attempting to return to the mouth 
of the net the fishes are entrapped. The cod-end is tied with a special knot in 
order that it may be readily opened when suspended over the deck of the trawler. 
Puate IIT 
The Otter-board. 
Fig. 1. The otter-boards, of which portion of the after one only is seen, have 
been hauled up from the bottom, and are being secured to the “ gallows.” The 
net is being gathered inboard, and one man is taking a dogfish out of the 
meshes. 
Fig. 2. The drawing represents an otter-board of the model before referred 
to; the chains are adjustable so that the boards may be set to the correct angle. 
In the drawing, the towing-warp (on the left) is shown parallel to the board; but 
when in use all four chains are tight, and the board, as it stands nearly upright, 
is deflected, thus offering the necessary resistance to the water to stretch the 
mouth of the net. The right side, or “ wing,” of the net is attached to the shackles 
shown above and below, the left wing being similarly fixed to the other otter- 
board. 
Prats IV. 
« Fig. 1. The winches. Each otter-board has its own warp and winding-drum. 
The winches can be driven forwards, backwards, or stopped independently, so 
that when the otter-boards near the surface of the water each can be separately 
got inboard. The net can be shot at either side of the vessel as convenient. 
Fig. 2. The net at the surface, buoyed by the expansion of the gases within 
the fishes themselves. The circular mass in the backeround is the cod-end, while 
the two lines of fishes in the foreground represent the examples caught in the: 
pockets. 
