.

JACKASSES. Heavy rough boats used in Newfoundland.

JACKASS PENGUIN. A bird, apt while on shore to throw its head backwards,
and make a strange noise, somewhat resembling the braying of an ass.

JACK-BARREL. A minnow.

JACK-BLOCK. A block occasionally attached to the topgallant-tie, and
through which the top-gallant top-rope is rove, to sway up or strike the
yard.

JACK-BOOTS. Large coverings for the feet and legs, outside all, worn by
fishermen.

JACK CROSS-TREES. Single iron cross-trees at the head of long
topgallant-masts, to support royal and skysail masts.

JACKEE-JA. A Greenland canoe.

JACKET. A doublet; any kind of outer coat.--_Cork jacket_, is lined with
cork in pieces, in order to give it buoyancy, and yet a degree of
flexibility, that the activity of the wearer may not be impeded in
swimming.

JACKETS. The casings of the passages by which steam is delivered into
the cylinders of steam-engines. They are non-conductors of heat to check
its escape.

JACKETTING. A starting, or infliction of the rope's-end.

JACK-HERN. A name on our southern coasts for the heron.

JACKING. Taking the skin off a seal.

JACK IN OFFICE. An insolent fellow in authority.

JACK IN THE BASKET. A sort of wooden cap or basket on the top of a pole,
to mark a sand-bank or hidden danger.

JACK IN THE BOX. A very handy engine, consisting of a large wooden male
screw turning in a female one, which forms the upper part of a strong
wooden box, shaped like the frustum of a pyramid. It is used by means of
levers passing through holes in it as a press in packing, and for other
purposes.

JACK IN THE BREAD-ROOM, OR JACK IN THE DUST. The purser's steward's
assistant in the bread and steward's room.

JACK-KNIFE. A horn-handled clasp-knife with a laniard, worn by seamen.

JACKMAN. A musketeer of former times, wearing a short mail jack or
jacket.

JACK NASTY-FACE. A cook's assistant.

JACK OF DOVER. An old sea-dish, the composition of which is now lost.
Chaucer's host in rallying the cook exclaims,

"And many a _Jack of Dover_ hast thou sold,
That hath been twies hot and twies cold."

JACK O' LANTERN. The _corpo santo_, or St. Elmo's light, is sometimes so
called.

JACK-PINS. A name applied to the fife-rail pins, also called
_Tack-pins_.

JACK ROBINSON.--_Before you could say Jack Robinson_, is a very old
expression for a short time,--

"A warke it ys as easie to be doone,
As tys to saye Jacke Robys