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.