An Universal Dictionary of the Marine / Or, a Copious Explanation of the Technical Terms and Phrases Employed in the Construction, Equipment, Furniture, Machinery, Movements, and Military Operations of a Ship. Illustrated With Variety of Original Designs of Shipping, in Different Situations; Together With Separate Views of Their Masts, Sails, Yards, and Rigging. to Which Is Annexed, a Translation of the French Sea-terms and Phrases, Collected from the Works of Mess. Du Hamel, Aubin, Saverien, &c.

by William Falconer

TRAVELLER, racambeau, a sort of thimble, whose diameter is much longer, in proportion to the breadth of its surface, than the common ones, fig. 3. plate [XII]. It is furnished with a tail formed of a piece of rope, about three feet in length, one end of which encircles the ring, to which it is spliced. These machines are principally intended to facilitate the hoisting or lowering of the top-gallant-yards at sea: for which purpose two of them are fixed on each back-stay, whereon they slide upwards and downwards, like the ring of a curtain upon its rod: being thus attached to the extremities of the top-gallant-yard, they prevent it from swinging backwards and forwards, by the agitation of the ship, whilst the yard is hoisting or lowering at sea.

TRAVERSE, in navigation, implies a compound course, or an assemblage of various courses, lying at different angles with the meridian. Thus fig. 2. plate [XI]. exhibits the traverses formed by a ship, when making an oblique progression against the direction of the wind, as explained in the article Tacking.

The true course and distance resulting from this diversity of courses is discovered by collecting the difference of latitude and departure of each course, and reducing the whole into one departure and one difference of latitude, according to the known rules of trigonometry. This reduction will immediately ascertain the base and perpendicular; or, in other words, will give the difference of latitude and departure to discover the course and distance. See Navigation.

Traverse-board, a thin circular piece of board, marked with all the points of the compass, and having eight holes bored in each, and eight small pegs hanging from the center of the board. It is used to determine the different courses run by a ship during the period of the watch; and to ascertain the distance of each course. This implement is particularly useful in light and variable winds, at which time the helmsman marks the course every half hour, by fixing a peg in that point of the compass whereon the ship had advanced. Thus, if the wind is northerly at the beginning of the watch, the ship, being close-hauled on the larboard tack, will steer W. N. W. If, after the first half hour, the wind changes to N. by W. the ship will fall off to W. by N. both of these courses are marked by the helmsman upon the traverse-board, by putting in one peg for every half hour on which she steers the same course; as, one peg into W. N. W. and two pegs into W. by N. if she sails an hour on the latter course; and so on. The lee-way and variation of the compass are afterwards allowed by the pilot, on summing up the whole.

TREE-NAILS, gournables, certain long cylindrical wooden pins, employed to connect the planks of a ship’s side and bottom to the corresponding timbers.

The tree-nails are justly esteemed superior to spike-nails or bolts, which are liable to rust, and loosen, as well as to rot the timber; but it is necessary that the oak of which they are formed should be solid, close, and replete with gum, to prevent them from breaking and rotting in the ship’s frame. They ought also to be well dried, so as to fill their holes when they are swelled with moisture. They have usually one inch in thickness to 100 feet in the vessel’s length; so that the tree-nails of a ship of 100 feet long, are one inch in diameter; and one inch and a half for a ship of 150 feet.

TRESTLE-TREES, tesseaux, two strong bars of timber fixed horizontally on the opposite sides of the lower mast-head, to support the frame of the top, and the weight of the top-mast. See Mast and Top.

TRIM, manege du navire, (trimman, Sax. to build) implies, in general, the state or disposition by which a ship is best calculated for the several purposes of navigation.

Thus the trim of the hold denotes the most convenient and proper arrangement of the various materials contained therein, relatively to the ships motion or stability at sea. The trim of the masts and sails is also their most apposite situation, with regard to the construction of the ship, and the effort of the wind upon her sails.

As the stowage of the hold, or the disposition of the several articles of the cargo, considerably affects the ship’s motion and stability, it will be necessary to give a general idea of the action of a heavy body upon the fluid that supports it, and the re-action of the fluid on the floating body.