, strongly moored, is used to mark dangers under water.
Lights are variously distinguished, as by the number, colour, and
continuity of their lights, whether flashing, revolving, &c.

LIGHT ICE. That which has but little depth in the water; it is not
considered dangerous to shipping, as not being heavy.

LIGHT INFANTRY. Troops specially trained to the extended and rapid
movements necessary to cover the man[oe]uvres of the main body.

LIGHTNING-CONDUCTOR. The lightning-conductor (introduced by Sir Snow
Harris) is a plate connected from the royal mast-head down to the deck,
thence by the beams to the ship's copper into the sea. Another kind is a
copper-wire chain or rope hoisted to the truck, then passing down by the
backstays over the channels into the sea.

LIGHT-PORT. A scuttle made for showing a light through. Also, a port in
timber ships kept open until brought deep by cargo. It is then secured
and caulked in. (_See_ RAFT-PORT.)

LIGHT-ROOM. In a ship-of-war, a small space parted off from the
magazine, having double-glass windows for more safely transmitting the
light by which the gunner and his assistants fill their cartridges.
Large ships generally have two light-rooms, the after and the fore.

LIGHTS. In men-of-war, all the seamen's lights are extinguished by 8
P.M., the officers' at 10, unless the commanding officer gives his
permission, through the master-at-arms, for a longer time, as occasion
may require.

LIGHT SAILS. All above the topgallant-sails; also the studding-sails and
flying jib. Men-of-war carry topgallant-sails over double reef.

LIGHT SHIP. In contradistinction to laden; a ship is said to be light
when she has no cargo, or merely in ballast. When very crank, she is
said to be _flying light_. Also, a vessel bearing a light as a guide to
navigators.

LIGHT WATER-DRAUGHT. The depth of water which a vessel draws when she is
empty, or nearly so.

LIGHT WATER-LINE. The line showing the depression of the ship's body in
the water when just launched, or quite unladen. (_See_ WATER-LINE.)

LIGNAMINA. Timber fit for building.

LIGNUM VITAE. _Guaiacum officinale._ A West Indian tree, of the wood of
which sheaves of blocks are made. It was allowed to be imported free of
all duties.

LIMB. The graduated arc of an astronomical or surveying instrument. In
astronomy, it is the edge or border of the disc of the sun, moon, or one
of the planets; in which sense we say the upper limb, the lower limb,
t