80 U. S. BUREAU OF FISHERIES. 
building the pot clear to the bottom, which would be expensive, as 
the pots of the traps are usually in quite deep water. If the trap is 
intended to catch the fish coming from only one direction, the lead 
generally runs to and is attached to one side of the entrance to the 
outer heart on the side opposite to that from which the fish are 
expected. 
Some traps have ‘‘jiggers’”’ (a hook-shaped extension of the outer 
heart) on each side, and sometimes on only one side, which help 
to turn the fish in the required direction. 
The “pot” is built out beyond the inner heart and immediately 
adjoining same. It is a square compartment, with web walls and 
bottom connected in the shape of a large square sack, fastened to 
piling on all sides. This pot is hauled up and down by means of 
ropes and tackles, either by hand or, as is most popular, by steam. 
The ‘“‘spiller’”’ is another square compartment adjoining either end 
of the pot (sometimes there are two spillers, one at each end), and is 
simply a container for fish. A small tunnel leads the fish from the 
pot into the spiller, whence the fishermen lift them out. This is 
accomplished by closing the tunnel from the pot, after which the 
ropes holding the front of the spiller are loosened and the net wall 
allowed to drop almost to the level of the water. A steam or gasoline 
tug then pushes a scow alongside the spiller and takes position on the 
outside of this scow. From the deck of the tug a derrick is rigged 
with a running line from the steam capstan through the block at the 
top of the derrick. This line is attached to the far end of a net apron, 
called a ‘‘brailer,” which is heavily weighted by having chains along 
each side and leaded crossways at several places. A small boat is 
run inside the spiller, and the men in this draw the brailer across the 
barge and let it sink in the spiller. The fish soon gather over it, 
when the steam capstan quiele ls reels it in, the net folding over as 
drawn in from its far side and spilling the fish out on the scow. Men 
on the scow pick out and throw overboard the undesirable fish. The 
apron is then drawn back across the pot and the operation repeated 
so long as any fish remain. In this manner a trap with many tons 
of salmon in it is quickly emptied. 
Traps, like nearly all other fixed fishing appliances, are built on 
the theory that salmon, like most other fishes, have a tendency to 
follow a given course in the water, whether a natural shore line or 
an artificial obstruction resembling one; also that the fish very seldom 
turns in its own wake. The trap has taken advantage of these natural 
tendencies of the fish, and is arranged so that, although the salmon 
may turn, he will continually be led by the wall of net toward and 
into the trap. 
If a trap is located in a place where fish play and where an eddy 
exists, and the fish run one way with the incoming tide and the 
opposite with the outgoing, it will fish from both directions; if located 
where the fish simply pass by, as for instance, on a point or reef, it 
will fish from one side only. 
A variation of the trap, to be used in places where piles can not be 
driven, is the floating trap. An experimental trap of this variety 
was used at Uganuk, on Kodiak Island, Alaska, as early as 1896. 
Its use was abandoned in 1897, not to be resumed until some years 
later. A number of floating traps (of the type invented by J. R. 
Heckman, of Ketchikan, Alaska) have been and are being used in 
