in navigation, an assemblage of several breadths of canvas sewed together by the hems, and edged round with cord, fastened to the yards of a ship, to make it drive before the wind. See Ship.

The edges of the cloths, or pieces, of which a sail is composed, are generally sewed together with a double seam: and the whole is skirted round at the edges with a cord, called the bolt-rope.

Although the form of sails is extremely different, they are all nevertheless triangular or quadrilateral figures; or, in other words, their surfaces are contained either between three or four sides.

The former of these are sometimes spread by a yard, as lateen-sails; and otherwise by a stay, as stay-sails; or by a mast, as shoulder-of-mutton sails; in all which cases the foremost leech or edge is attached to the said yard, mast, or stay, throughout its whole length. The latter The principal sails of a ship (Plate CCLX. fig. 2) are the courses or lower sails \(a\); the top-falls \(b\), which are next in order above the courses; and the top-gallant sails \(c\), which are expanded above the top-falls.

The courses are the main-fall, fore-fall, and mizen main stay-fall, fore-stay fall, and mizen-stay fall; but more particularly the three first. The main-stay fall is rarely used except in small vessels.

In all quadrangular sails the upper edge is called the head; the sides or skirts are called leeches; and the bottom or lower edge is termed the foot. If the head is parallel to the foot, the two lower corners are denominated clues, and the upper corners earings.

In all triangular sails, and in those four-sided sails wherein the head is not parallel to the foot, the foremost corner at the foot is called the tack, and the after lower corner the clue; the foremost perpendicular or sloping edge is called the fore-leech, and the hindmost the after-leech.

The heads of all four-sided sails, and the fore-leeches of lateen-sails, are attached to their respective yard or gaff by a number of small cords called ro-bands; and the extremities are tied to the yard arms, or to the peak of the gaff, by earings.

The stay-falls are extended upon stays between the masts, whereon they are drawn up or down occasionally, as a curtain slides upon its rod, and their lower parts are stretched out by a tack and sheet. The clues of a top-fall are drawn out to the extremities of the lower yard, by two large ropes called the top-fall sheets; and the clues of the top-gallant sails are in like manner extended upon the top-fall yard-arms, as exhibited by fig. 2.

The studding-sails are set beyond the leeches or skirts of the main-fall and fore-fall, or of the top-falls or top-gallant sails of a ship. Their upper and lower edges are accordingly extended by poles run out beyond the extremities of the yards for this purpose. Those sails, however, are only set in favourable winds and moderate weather.

All sails derive their name from the mast, yard, or stay, upon which they are extended. Thus the principal sail extended upon the main-mast is called the main sail, \(d\); the next above, which stands upon the main-top mast is termed the main-top sail, \(e\); and the highest, which is spread across the main-top-gallant mast, is named the main top-gallant sail, \(f\).

In the same manner there is the fore-fall, \(g\); the fore-top-fall, \(h\); and the fore-top-gallant-fall, \(i\); the mizen, \(k\); the mizen top-fall, \(l\); and mizen top-gallant-fall, \(m\). Thus also there is the main-stay fall, \(o\); main-top-mast stay-fall, \(p\); and main-top-gallant stay-fall, \(q\); with a middle stay-fall which stands between the two last.

N.B. All these stay-falls are between the main and fore masts.

The stay-falls between the main-mast and mizen-mast are the mizen stay-fall, \(r\); and the mizen top-mast stay-fall, \(s\); and sometimes a mizen top-gallant stay-fall above the latter.

The stay-falls between the fore-mast and the bow-sprit are the fore stay-fall, \(t\); the fore top-mast stay-fall, \(u\); and the jib, \(x\). There is besides two square sails extended by yards under the bow-sprit, one of which is called the sprit-fall, \(y\); and the other the sprit-fall top fall, \(z\).

The studding-sails being extended upon the different yards of the main-mast and fore-mast, are likewise named according to their stations, the lower, top-mast, or top gallant studding sails.

The ropes by which the lower yards of a ship are hoisted up to their proper height on the masts, are called the jibs. In all other falls the ropes employed for this purpose are called halliards.

The principal sails are then expanded by halliards, sheets, and bowlines; except the courses, which are always stretched out below by a tack and sheet. They are drawn up together, or trussed up, by bunt-lines, clue-lines, \(d\); leech-lines, \(e\); reef tackles, \(f\); flab-line, \(g\); and spiling-lines. As the bunt-lines and leech-lines pass on the other side of the fall, they are expressed by the dotted lines in the figure.

The courses, top-falls, and top-gallant sails, are wheeled about the mast, so as to suit the various directions of the wind by braces. The higher studding-sails, and in general all the stay-falls, are drawn down, so as to be furled, or taken in, by down-hauls.

Sail is also a name applied to any vessel beheld at a distance under sail.

To Set Sail, is to unfurl and expand the sails upon their respective yards and stays, in order to begin the action of sailing.

To Make Sail, is to spread an additional quantity of sail, so as to increase the ship's velocity.

To Shorten Sail, is to reduce or take in part of the sails, with an intention to diminish the ship's velocity.

To Strike Sail, is to lower it suddenly. This is particularly used in saluting or doing homage to a superior force, or to one whom the law of nations acknowledges as superior in certain regions. Thus all foreign vessels strike to a British man of war in the British seas.