across the masts at right angles, and the latter obliquely.

The square yards are nearly of a cylindrical surface. They taper from the middle, which is called the slings, towards the extremities, which are termed the yard-arms; and the distance between the slings and the yard-arms on each side is by the artificers divided into quarters, which are distinguished into the first, second, third quarters, and yard arms. The middle quarters are formed into eight squares, and each of the end parts is figured like the frustum of a cone. All the yards of a ship are square except that of the mizen.

The proportions for the length of yards, according to the different classes of ships in the British navy, are as follows:

| Yard | Guns | Yard | |------|-----|------| | 560 | main-yard, fig. 1 | 100 | | 559 | Pl. CCCCLXXVIII. | 90 80 | | 570 | Note, the figure represents the yard and sails of a ship of 74 guns. | 70 | | 575 | 50 | | 561 | all the rest. |

To apply this rule to practice, suppose the gun-deck 144 feet. The proportion for this length is, as 1000 is to 575, so is 144 to 83; which will be the length of the main-yard in feet, and so of all the rest.

| Yard | Guns | |------|-----| | 820 | mizen-yard | | 847 | 70 | | 840 | 24 | | 726 | main topsail yard | | 720 | all the rest. | | 726 | fore topsail-yard | | 720 | all the rest. | | 696 | main top gallant yard all the rest. | | 692 | force top gallant yard all the rest. | | 768 | mizen topsail-yard all the rest. |

Cross jack and sprit-sail yards equal to the fore topsail-yard.

Sprit-topsail-yard equal to the fore top-gallant-yard.

The diameters of yards are in the following proportions to their length.

The main and fore yards five-sevenths of an inch to one yard. The topsail, cross-jack, and sprit-sail yards, nine-fourteenths of an inch to one yard. The top-gallant, mizen topsail, and sprit-sail topsail yards, eight-thirteenths of an inch to one yard.

The mizen-yard five ninths of an inch to one yard.

All studding-sail booms and yards half an inch to one yard in length.

The lifts of the main-yard are exhibited in the above figure by g g; the horses and their stirrups by h i; the reef-tackles and their pendents by k l; and the braces and brace-pendents by m n.

The lateen-yards evidently derive their names from having been peculiar to the ancient Romans. They are usually composed of several pieces fastened together by woodings, which also serve as steps whereby the sailors climb to the peak or upper extremity, in order to furl or cast loose the sail.

The mizen-yard of a ship, and the main-yard of a bilander, are hung obliquely on the mast, almost in the same manner as the lateen-yard of a xebec, sotte, or polacre.a measure of length used in Britain and Spain, consisting of three feet, chiefly to measure cloth, stuffs, &c. Yard-Arm is that half of the yard that is on either side of the mast, when it lies athwart the ship.