354 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
the same shape, thus doing away with all sharp angles and equalizing the strain 
over the various parts of the head of the net, besides carrying it higher in rear of 
the beam, giving the mouth a wider opening and greatly increasing its strength and 
efficiency. It is better balanced also and less liable to capsize in lowering or to catch 
on foul bottom; it is more simple in construction, and lighter by about 100 pounds, 
which is an advantage in handling it in a seaway. The jackstays and guard nets 
sometimes attached to the inner surfaces of the runners are useful in shoal water and 
in moderate depths, where swift-moving forms are mostly encountered. 
The frame is composed of an iron beam having a brass collar screwed on each 
end and held rigidly in iilace by set screws. Each collar has two holes, through which 
square-headed bolts, with nuts, are passed for the purpose of securing it to its runner, 
the bolts being habitually carried in their respective holes ready for use. 
Eyebolts, to which the bridles are seized, are secured to the forward ends of the 
runners by nuts. Beams and runners are interchangeable. 
THE TANNER BEAM TRAWL No. 1. 
The trawl is here reiireseuted completely mounted (plate xxxii), ready for service, 
showing the method of attaching trawl net, bridles, wing nets, and mud bag, and, 
as it has become the standard on board the Alhatross for general work, it will be 
described in detail. 
To assemble the Tanner beam trawl, plac'e the runners h and beam a in position, 
pass the bolts through holes in the collars ]) and runners /q and set the nuts tight 
with a wrench; place the head cringles or eyes of the trawl net over the heads of the 
beam set screws, middle a piece of 9-thread manila, and, commencing Avith the bight 
at the center of the beam, lace both Avays to the beam ends, thence doAAm the backs of 
the runners, securing the apron in the same manner, and, if there is end to spare, Avrap 
it around the rear bends above tlie lead-ro])e hitches. Bend tlie free ends of the lead 
rope to the rear extremities of the runners, as low doAvn as iiracticable, Avith a clove 
hitch, taking jamming turns above, if necessary, to prevent its slipping up; if there 
are spare ends, stop them along the back of the runners. Adjust the draAvstring at 
the bottom of the pocket d, seize the bridle stops o, gather in the tail of the net and the 
bridle legs, pass the lashing /(, and hitch the mud bag i to the eyes of the bridle legs. 
The. wing nets I are kept slung to the arms A:, and to attach them to the traAvl 
loosen the beam set-screws and slip them into the ends of the beam about G inches and 
hold them in place by again tightening the set-screAV. TraAvl Aveights are used to 
facilitate the sinking of the net, and ordinarily a single Aveight of 28 pounds is 
attached to each runner by a long tail rope, and one to the end of the net by a short 
