316 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
this is as follows : If the trawl upsets, the point b of the catch, which is 
inches long, strikes the bottom and turns back, moving on the pin d r 
until it rests against the upper part of the head iron. This movement ; 
causes the point c of the device to stand out at right angles with the] 
head-iron, and as the trawl is dragged along over the ground this point 
sticks into the bottom, and either stops the progress of the vessel or 
causes the apparatus to have a sort of jerky motion, whieh indicates to 
the fisherman that his gear is capsized ; he therefore proceeds at once 
to get it into proper position for fishing. 
(c). The Trawl-Net. 
That portion of the apparatus to which the term “trawl” is more 
especially applied is the net. It is formed of several sections, each of 
which has a technical name, there being, however, local differences asj 
to the terms applied. 
Fig. 6. 
Fig. 7. 
. 
There are other kinds of trawl-nets, such, for instance, as the otter 
trawl (Figs. 6 and 7), which do not have a beam. 
