OUND BLOCKS. Those which are fitted with iron strops.

IRON-CLAD, CASED, COATED, OR PLATED VESSEL. One covered entirely, or in
special parts, with iron plates intended to resist ordinary missiles.
Where parts only are so protected, of course it may be done more
effectually.

IRON GARTERS. A cant word for bilboes, or fetters.

IRON-HORSE. The iron rail of the head; the horse of the fore-sheet or
boom-sheet traveller.

IRON-PLATED SHIPS. _See_ ARMOUR-CLAD.

IRONS. A ship is said to be in irons when, by mismanagement, she is
permitted to come up in the wind and lose her _way_; so that, having no
steerage, she must either be boxed off on the former tack, or fall off
on the other; for she will not cast one way or the other, without
bracing in the yards. Also, _bilboes_ (which see). Also, the tools used
by the caulkers for driving oakum into the seams. (_See also_
BOOM-IRONS.)

IRON-SICK. The condition of vessels when the iron work becomes loose in
the timbers from corrosion by gallic acid, and the speeks or sheathing
nails are eaten away by rust.

IRON-SIDES. Formerly a sobriquet for favourite veteran men-of-war, but
latterly applied to iron and iron-clad ships.

IRON WEDGES. Tapered iron wedges on the well-known mechanical principle,
for splitting out blocks and for other similar purposes.

IRON-WORK. A general name for all pieces of iron, of whatever figure or
size, which are used in the construction and equipment of ships.

IRREGULAR BASTION. One whose opposite faces or flanks do not correspond;
this, as well as the constant irregularity of most real fortification,
is generally the result of the local features of the neighbourhood.

ISLAND. May be simply described as a tract of land entirely surrounded
with water; but the whole continuous land of the Old World forms one
island, and the New World another; while canals across the isthmuses of
Suez and Panama would make each into two. The term properly only applies
to smaller portions of land; and Australia, Madagascar, Borneo, and
Britain are among the larger examples. Their materials and form are
equally various, and so is their origin; some having evidently been
upheaved by volcanic eruption, others are the result of accretion, and
still more revealing by their strata that they were formerly attached to
a neighbouring land. The sudden emergence of Sabrina, in the Atlantic,
has occasioned wonder in our own day. So has that of Graham's Island,
near the south co