140 MANUAL OF THE MOLLUSCA. 
The side frames are of iron, the upper beam of wood, and the lower 
edge of the net is kept down to the ground by means of a chain, 
which is wolded or wrapped round with old rope. The beam is 
generally from 40 to 50 feet in length, and about § inches square. 
The net is about 30 yards in depth, and has a couple of pockets 
inside. The end is untied when the net is hauled on board for 
the purpose of taking the fish out. These nets can only be 
worked where the bottom of the sea is free from rocks. They 
are used by boats of 35 to 60 tons, manned by crews of from four 
to six men and two to three or four boys. In the vicinity of 
Scarbro’ they fish between the shore-reefs and the off rock, which 
is 4 to 10 miles from land; the bottom is sand or clay, with 4 to 15 
fathom water on the land side, and 17 to 25 fathoms on the off 
side.”’ Immense quantities of crustacea and shell-fish are taken 
with the trawl, as well as ground-fish. 
Kettle-nets.—On the flat, sandy coast of Kent and Sussex, the 
mackerel-fishery 1s pursued by setting up stakes 10 or 15 feet 
high, at distances of 10 feet apart, in lines running outwards 
from the shore at high-water, to low-water neap tides, where 
they are turned in the direction of the tide. To these 
stakes nets are attached, and leaded, which remain as long as 
the fish are on the coast. Cuttle-fish are frequently taken in 
these nets. 
Deep-sea Fishery.—In North Britain an extensive ground- 
fishery is conducted by means of long lines—often a mile in 
length—with hooks and baits every few yards. These lines 
are laid out at night near the coast, and taken up the next 
morning. When used out at sea, the boats lay by for a few 
hours, and then take up the lines. The carnivorous whelks 
adhere to the baits (which haye not been seized by fishes), and 
sometimes a bushel of them are taken in this way from a single 
line. Rhynchonella psittacea, Panopea Norvegica, Velutine, and 
some of the scarce Fusi, haye been obtained from these lines, 
fhe bivalves haying been entangled accidentally by the hooks. 
For trapping whelks on rocky ground a net may be made such 
as is used for crabs and lobsters, by attaching a loose bag to an 
iron ring of a yard across. This is fastened to a rope by three 
equal strings, baited with dead fish, and let down from a vessel 
at anchor, or, still better, from a buoy. It is put down oyer- 
night, and hauled up gently in the morning. 
Mr. D’Urban informs us that Natica Alderi and monilifera 
are frequently found in the lobster-pots at Bognor, Sussex, 
which they enter to feed upon the bait. 
Dredging. — The dredges used in the oyster and whelk- 
