Brigantine

In the late 17th century, the Royal Navy used the term brigantine (often contracted to brig) to refer to small two-masted vessels designed to be rowed as well as to sail, rigged with square sails on both masts.

By the first half of the 18th century the word had evolved to refer not to a ship type name, but rather to a particular type of rigging: square-rigged on the foremast and fore-and-aft rigged on the mizzen. Many sloops were "brigantine-rigged".

The 1780 Universal Dictionary of the Marine by William Falconer defines brig and brigantine as follows:

BRIG, or BRIGANTINE, a merchant-ship with two masts. This term is not universally confined to vessels of a particular construction, or which are masted and rigged in a method different from all others. It is variously applied, by the mariners of different European nations, to a peculiar sort of vessel of their own marine.

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Among English seamen, this vessel is distinguished by having her main-sail set nearly in the plane of her keel; whereas the main-sails of larger ships are hung athwart, or at right angles with the ship’s length, and fastened to a yard which hangs parallel to the deck: but in a brig, the foremost edge of the main-sail is fastened in different places to hoops which encircle the main-mast, and slide up and down it as the sail is hoisted or lowered: it is extended by a gaff above, and by a boom below.

Later, brig and brigantine developed distinct meanings. The Oxford English Dictionary (with citations from 1720 to 1854) defines brig as:

1. a. A vessel

(a) originally identical with the brigantine (of which word brig was a colloquial abbreviation); but, while the full name has remained with the unchanged brigantine, the shortened name has accompanied the modifications which have subsequently been made in rig, so that a brig is now

(b) A vessel with two masts square-rigged like a ship's fore- and main-masts, but carrying also on her main-mast a lower fore-and-aft sail with a gaff and boom.

A brig differs from a snow in having no try-sail mast, and in lowering her gaff to furl the sail. Merchant snows are often called brigs. This vessel was probably developed from the brigantine by the men-of-war brigs, so as to obtain greater sail-power.