NUMBER. The number on the ship's books is marked on the clothing of seamen; that on a man's hammock or bag corresponds with his number on the watch and station bill. The ships of the royal navy are denoted by flags expressing letters, and when passing or nearing each other the names are exchanged by signals.—Losing the number of the mess, is a phrase for dying suddenly; being killed or drowned.
NUMERARY OR MARRYAT'S SIGNALS. A useful code used by the mercantile marine, by an arrangement of flags from a cypher to units, and thence to thousands. (See [Signals].)
NUN-BUOY. A buoy made of staves, somewhat in the form of a double cone; large in the middle, and tapering rapidly to the ends; the slinging of which is a good specimen of practical rigging tact.
NURAVEE YAWL. A corruption of [Norway yawl] (which see).
NURSE. An able first lieutenant, who in former times had charge of a young boy-captain of interest, but possessing no knowledge for command. Also, a small kind of shark with a very rough skin; a dog-fish.
NUT. A small piece of iron with a female screw cut through the middle of it, for screwing on to the end of a bolt.
NUTATION. An oscillatory motion of the earth's axis, due chiefly to the action of the moon upon the spheroidal figure of our globe.
NUTS of an Anchor. Two projections either raised or welded on the square part of the shank, for securing the stock to its place.
NYCTALOPIA. See [Moon-blink].