To TACK (continued)

By this principle it is easy to conceive how a ship is compelled to turn into any direction, by the force of the wind acting upon her sails, in horizontal lines. For the sails may be so arranged as to receive the current of air, either directly, or more or less obliquely: hence the motion communicated to the sails must of necessity conspire with that of the wind upon their surfaces. To make the ship tack, or turn round with her head to the windward, it is therefore necessary, after she has received the first impression from the helm, that the head-sails should be so disposed as to diminish the effort of the wind; in the first instant of her motion, and that the whole force of the wind should be exerted on the after-sails, which, operating on the ship's stern, carries it round like a weather-cock. But since the action of the after-sails, to turn the ship, will unavoidably cease when her head points to the windward, it then becomes necessary to use the head-sails, to prevent her from falling-of, and returning to her former situation. These are accordingly laid aback on the lee-side, to push the vessel's fore-part towards the opposite side, till she has fallen into the line of her course thereon, and fixed her sails to conform with that situation.

It has been observed above, that the first effort to turn the ship in tacking is communicated by the helm, which is then put to the lee-side. This circumstance being announced by the pilot, or commanding-officer, who then calls out, Helm's a-lee! the head-sails are immediately made to shiver in the wind, by casting loose their sheets or bowlines. The pilot then calls, Up tacks and sheets! which is executed by loosening all the ropes which confine the corners of the lower sails, in order that they may be more readily shifted to the other side. When the ship has turned her head directly to windward, as in d, fig. 2. plate XI. the pilot gives the order to turn about the sails on the main and mizen-masts, by the exclamation, Haul main-sail, haul! the bowlines and braces are then instantly cast off on one side, and as expeditiously drawn in on the other side, so as to wheel the yards about their masts: the lower corner of the main-sail is, by means of its tack, pulled down to its station at the chestree; and all the after-sails are, at the same time, adjusted to ifand upon the other board. Finally, when the ship has fallen off five or six points, as h, fig. 2. plate XI. the pilot cries, Haul of all! or, Let go, and haul! then the sails on the fore-mast are wheeled about by their braces: and as the ship has then a tendency to fall-off, she is checked by the effort of the helm, which for that purpose is put hard a-lee. The fore-tack, or the lower corner of the fore-sail, being fixed in its place, the bowlines are hauled; and the other sails, which have been neglected in the hurry of tacking, are properly arranged to the wind; which exercise is called trimming the sails. See LEE-WAY and SAILING.

Plate XI

Reference Works