Chapter L: L, the deck-transom (2)

TRANSOMS, _barres d’arcasse_, (_transenna_, Lat.) certain beams or timbers extended across the _stern-post_ of a ship, to fortify her after-part, and give it the figure most suitable to the service for which she is calculated.

Transoms are here defined _beams_ or _timbers_, because they partake equally of the form and purpose of those pieces. Thus the deck-transom is the aftmost or hindmost beam of the lower deck, whereon all the deck-planks are rabetted: and all the transoms are fixed athwart the stern-post, in the same manner as the floor-timbers are laid upon the keel. As the floor-timbers also, with regard to their general form and arrangement, have a _rising_, by which, the bottom becomes narrower as it ascends towards the extremities; so the arms of the transoms, being gradually closer in proportion to their distance from the wing-transom downwards, give a similar figure to that part of the ship, which accordingly becomes extremely narrow, from the counter towards the keel; and this general figure or curve is called the _flight_ of the transoms.

Although these pieces are therefore extremely different in their figures, according to the extent of the angles formed by their branches or horns, each of them has nevertheless a double curve, which is partly vertical, and partly horizontal, with regard to its situation in the ship. The former of these is called, by the artificers, the round-up, and the latter the _round-aft_.

As the transoms fill up the whole space comprehended between the head of the stern-post above, and the aftmost floor-timbers below, it is necessary to distinguish them by particular names. Thus the highest is called the wing-transom: the next, the deck-transom; and afterwards follow the first, second, and third transoms; together with the intermediate ones, as represented in fig. 1. plate X. and described in the explanation thereof.

The vertical direction of the arms or angles of the transoms, with regard to the ship’s length, are expressed in the plane of ELEVATION; and their horizontal curves are also delineated on the plane of Projection; both of which are represented under those terms in plate I. and described in the general explanation of the planes in the article _Naval_ ARCHITECTURE.

The highest transoms are connected to the ship’s quarter by knees, which are bolted to those pieces, and to the after-timbers. See the article SLEEPERS.

TRANSPORT. See the article SHIP.

TRANSPORTING, the act of removing a ship from one place to another, by the help of anchors and ropes. See WARPING.

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.

The whole weight of any body, then, may be considered as united in its center of gravity; so that, if it were suspended by a line fastened to this center, the line would hang in a perpendicular position, as directed through the center of gravity to the center of the earth. A body which floats in a fluid is not, however, supported by its center of gravity, but by the compression of the surrounding filaments of water: and each of these, being considered as infinitely small, will act upon a very minute portion of the surface of the floating body, with regard to the specific gravity, and conform to a principle applicable to all fluids, in proportion to the height of these filaments, viz. That the weight of a column of any fluid will be in proportion to the specific gravity of the fluid and the height of the column multiplied by its base.

But as heavy bodies endeavour, by their gravity, to approach the center of the earth, in a vertical line passing through their centers; so the pressure of fluids endeavours to carry bodies in a vertical, tending from the center of the earth towards their surface, and passing through the center of gravity of the submerged part, which forces them towards the surface. So, in any submerged body at rest, these two opposite forces coincide in the same vertical, acting in a direction quite contrary to each other. _Bouguer’s Traité du navire._

From this theory it results, that the stability or trim of a ship chiefly depends upon her construction, as considering the bottom to be homogeneous. This, however, can only happen when her cargo consists of the same materials throughout, as with corn, salt, or any species stowed in bulk, and when her hold is entirely filled. For if the ship has not sufficient breadth to resist the effort of the wind upon her sails; or if she is built too high, or too sharp in the floor, her center of gravity will be too high, and she will be very _crank_, i. e. apt to overturn.

But as the _stiffness_ of a ship, or quality to carry sail without danger of overturning, depends very much on the _stowage_ of the hold, the center of gravity may thereby be considerably lowered, by which her stability will be increased in proportion. It is a general maxim amongst mariners, that a ship will not carry sufficient sail till she is laden so deep that the surface of the water may glance on her extreme breadth _amidships_. She must therefore have a great deal of weight, as ballast, &c. to bring her to this situation, which is called a good sailing trim.

Several circumstances are also to be particularly considered with regard to the quality, weight, and stowage of the ballast. The center of gravity being placed too high, will render the ship incapable of carrying a sufficient quantity of sail; and by having it too low, she will be in danger of rolling away her masts. When it is placed too far forward, the ship will _pitch_, and _labour_ heavily; and when too far aft, she will occasionally be exposed to the dangerous circumstance of a _pooping_ sea. These extremes being carefully avoided, it remains to proportion the contents of every part of the _hold_ to its capacity, and to place the lightest materials uppermost. See STOWAGE.

TRIM, when applied to the sails, denotes the general arrangement which is best calculated to accelerate the ship’s course, according to the direction of the wind. See the article SAILING.

If the ship were always to sail before the wind, it would be a very simple operation to trim the sails; because nothing else could be required than to dispose them so as to receive the greatest possible effort of the wind, which is evidently performed by arranging them at right angles with its direction. But, when the current of wind acts more directly upon the ship’s side, it necessarily falls more obliquely on the surface of the sails, so as to diminish their effort to push the ship forward; and to augment their tendency to make her incline to one side. Hence we may conclude, that an increase of the wind, when accompanied with a variation unfavourable to the ship’s course, will by no means augment her velocity; because the force previously employed to push her forward, will afterwards operate to overturn her; and because this impression renders it necessary to reduce the quantity of sail; the effort of which is farther diminished by the obliquity of the action of the wind upon its surface.

By this theory it appears, that the effect of the wind to advance the ship decreases in proportion to its obliquity with any sail upon which it operates.

The mechanical disposition of the sails, according to every direction of the wind upon their surfaces, is copiously described in the articles CLOSE-HAULED, LARGE, SAILING, and TACKING.

TRIM, when expressed of the masts, denotes their position with regard to the ship and to each other. Thus, in the latter sense, they should neither be too near nor too far apart; and, in the former, they should not be too far forward or aft; and, according to the situation or quality which communicates a greater velocity to the vessel, they should either be upright, or inclining aft, or forward.

TRIM _the boat_. See BOAT, and the phrases succeeding it.

_Sharp_-TRIMMED, the situation of a ship’s sails in a scant wind.

TRIMONEER, a barbarous corruption of TIMONEER. See that article.

TRIP, a cant phrase, implying an outward-bound voyage, particularly in the coasting navigation. It also denotes a single _board_ in _plying_ to windward.

TRIPPING, the movement by which an anchor is loosened from the bottom by its cable or buoy-ropes. See ATRIP.

TROUGH, a name given to the hollow, or interval between two high waves, which resembles a broad and deep trench perpetually fluctuating. As the _setting_ of the sea is always produced by the wind, it is evident that the waves, and consequently the trough or hollow space between them, will be at right angles with the direction of the wind. Hence a ship rolls heaviest when she lies in the trough of the sea.

TROWSERS, a sort of loose breeches of canvas worn by common sailors.

TRUCK, a piece of wood, which is either conical, cylindrical, spherical, or spheroidical.

Thus the trucks fixed on the spindle of a mast-head, and which are otherwise called _acorns_, are in the form of a cone: and those which are employed as wheels to the gun-carriages are cylinders. The trucks of the parrels assume the figure of a globe; and, lastly, those of the flag-staffs resemble an oblate spheroid. See the articles ACORN, CANNON, PARREL, and FLAG-STAFF.

Trucks of the shrouds are nearly similar to those of the parrels: they are fastened to the shrouds about twelve or fourteen feet above the deck, the hole in the middle being placed perpendicularly to contain some rope which passes through it. The intention of these is to guide the sailors to the particular rope, which might otherwise be easily mistaken for some other of the same size, especially in the night.

_Speaking_-TRUMPET, _trompette marine_, a trumpet of brass or tin used at sea, to propagate the voice to a great distance, or to convey the orders from one part of the ship to another, in tempestuous weather, &c. when they cannot otherwise be distinctly heard by the persons to whom they are directed.

_Fire_-TRUNK. See the article FIRE-SHIP.

TRUNNIONS, _tourillons_, the two knobs or arms which project from the opposite sides of a piece of artillery, and serve to support it in the carriage. See CANNON and MORTAR.

TRUSS, (_trousse_, Fr.) a machine employed to pull a yard home to its respective mast, and retain it firmly in that position.

As the truss is generally used instead of a parrel, it is rarely employed, except in flying top-gallant-sails, which are never furnished with parrels. It is no other than a ring or traveller, which encircles the mast, and has a rope fastened to its after-part, leading downward to the top or decks; by means of which the truss may be straitened or slackened at pleasure. The _haliards_ of the top-gallant-sail being passed through this ring; and the sail being hoisted up to its utmost extent; it is evident, that the yard will be drawn close to the mast, by pulling down the truss close to the upper part of the sail. For, without the truss, the sail and its yard would be blown from the mast, so as to swing about, by the action of the wind, and the rocking of the vessel; unless the yard were hoisted close up to the pulley wherein the haliards run; which seldom is the case in flying top-gallant-sails, because they are usually much shallower than those which are fixed or _standing_.

TRUSS-PARREL. See PARREL.

TRYING, _à la cape_, the situation in which a ship lies nearly in the _trough_ or hollow of the sea in a tempest, particularly when it blows contrary to her course.

In _trying_, as well as in _scudding_, the sails are always reduced in proportion to the increase of the storm. Thus, in the former state, a ship may lie by the wind under a whole main-sail, a whole fore-sail, or a whole mizen; or under any of those sails, when diminished by the _reef_ or _balance_. As the least possible quantity of sail used in scudding are the _goose-wings_ of the foresail; so in _trying_, the smallest portion is generally the mizen-staysail or main-staysail: and in either state, if the storm is excessive, she may lie with all the sails furled, or, according to the sea-phrase, _under bare poles_.

The intent of spreading a sail at this time is to keep the ship more steddy, and, by pressing her side down in the water, to prevent her from rolling violently; and also to turn her _bow_ towards the direction of the wind, so that the shock of the waves may fall more obliquely on her flank, than when she lies along the trough of the sea. While she remains in this situation, the helm is fastened close to the lee-side, or, in the sea-language, _hard a-lee_, to prevent her as much as possible from falling-off. But as the ship is not then kept in equilibrio by the effort of her sails, which at other times counterbalance each other at the _head_ and _stern_, she is moved by a slow but continual vibration, which turns her head alternately to windward and to leeward, forming an angle of three or four points in the interval. That part where she stops, in approaching the direction of the wind, is called her _coming-to_, and the contrary excess of the angle _to leeward_ is termed her _falling-off_.

Thus, suppose the wind northerly, and a ship trying with her starboard side to windward: if, in turning her head towards the source of the wind, she arrives at N. W. ½ N. or N. 39° W. and then declines to the leeward as far W. ½ S. or S. 84° W, the former will be called her coming-to, and the latter her falling-off. In this position she advances very little according to the line of her length, but is driven considerably to leeward, as described in the articles DRIFT and LEE-WAY.

TUCK, a name given to that part of the ship where the ends of the bottom-planks are collected together immediately under the stern or counter.

When this part, instead of being incurvated, and forming a convex surface, assumes the shape of a vertical or oblique plane, it is said to be square, as represented in fig. 8. plate IX. A square tuck is accordingly terminated above by the wing-_transom_, and below and on each side by the _fashion-pieces_.

TUMBLING-HOME, _encabanement_, that part of a ship’s side which falls inward above the extreme breadth, so as to make the ship gradually narrower from the lower deck upwards. This angle is represented in general throughout all the timbers in the plane of _projection_, plate I. It is also more particularly expressed by Q T in the MIDSHIP-FRAME, plate VII. where it is evident, that the ship grows narrower from Q towards T. N. B. In all our old sea-books, this narrowing of a ship from the extreme breadth upwards is called housing-in. See UPPER-WORK.

TURNING-_to-windward_, _chicaner le vent_, that operation in sailing wherein a ship endeavours to make a progress against the direction of the wind, by a compound course, inclined to the place of her destination. This method of navigation is otherwise called _plying_. See also BEATING and TACKING.

TYE, _itague_, a sort of _runner_ or thick rope, used to transmit the effort of a tackle to any _yard_ or _gaff_, which extends the upper part of a sail.

The tye is either passed through a block fixed to the mast-head, and afterwards through another block moveable upon the yard or gaff intended to be hoisted; or the end of it is simply fastened to the said yard or gaff, after communicating with the block at the mast-head. See also the article JEARS.

V.

VAN, _avante-garde_, the foremost division of any naval armament, or that part which usually leads the way to battle; or advances first in the order of sailing. See CENTER, FLEET, and REAR.

VANE, a thin slip of bunting hung to the mast-head, or some other conspicuous place in the ship, to show the direction of the wind. See _b_, fig. 1. plate I. It is commonly sewed upon a wooden frame called the stock, which contains two holes whereby to slip over the spindle, upon which it turns about as the wind changes.

_Dog_-VANE, _panon_, a small light vane, formed of a piece of packthread about two feet in length, upon which are fixed five or six thin slices of cork stuck full of light feathers. It is usually fastened to the top of a staff two yards high, which is placed on the top of the ship’s side on the quarter-deck, in order to shew the direction of the wind to the helmsman, particularly in a dark night, or when the wind is extremely feeble.

VANGS, a sort of _braces_ to support the mizen _gaff_, and keep it steddy. They are fixed on the outer-end or _peek_, and reach downwards to the aftmost part of the ship’s side, where they are hooked and drawn tight, so as to be slackened when the wind is _fair_; and drawn in to windward when it becomes unfavourable to the ship’s course.

VARIATION, the angle contained between the true meridian and the magnetic meridian.

‘After the discovery of that most useful property of the magnet, or loadstone, namely, the giving hardened iron and steel a polarity, the compass was for many years used without knowing that its direction in any wise deviated from the poles of the world: and about the middle of the 16th century, so certain were some of its inflexibly pointing to the north, that they treated with contempt the notion of the variation, which about that time began to be suspected[55]. However, careful observations soon discovered, that in England, and its neighbourhood, the needle pointed to the eastward of the true north: but the quantity of this deviation being known, mariners became as well satisfied as if the compass had none; because they imagined that the true course could be obtained by making allowance for the true variation.

‘From successive observations made afterwards, it was found, that the deviation of the needle from the north was not a constant quantity; but that it gradually diminished, and at last, about the year 1660, it was found at London that the needle pointed due north, and has ever since been getting to the westward, and now the variation is more than 20 degrees to the westward of the north: so that in any one place it may be suspected the variation has a kind of libratory motion, traversing through the north to unknown limits eastward and westward. But the settling of this point must be left to time.

‘During the time of the said observations it was also discovered, that the variation of the needle was different in different parts of the world, it being west in some places when it was east in others; and in places where the variation was of the same name, yet the quantity of it greatly differed. It was therefore found necessary, that mariners should every day, or as often as they had opportunity, make, during their voyage, proper observations for an amplitude or azimuth; whereby they might be enabled to find the variation of the compass in their present place, and thence correct their courses.’ _Robertson’s Elements of navigation._

Dr. Halley published, in the last century, a theory of the variations of the compass. In this work he supposes there are four magnetic poles in the earth, two of which are fixed and two moveable, by which he explains the different variation of the compass, at different times, in the same place. But it is impossible to apply exact calculations to so complicated an hypothesis. M. Euler, son of the celebrated geometrician of that name, has however shewn, that two magnetic poles placed on the surface of the earth will sufficiently account for the singular figure assumed by the lines which pass through all the points of equal variation in the chart of Dr. Halley.

M. Euler first examines the case, wherein the two magnetic poles are diametrically opposite; 2d. he places them in the two opposite meridians, but at unequal distances from the poles of the world; 3d. he places them in the same meridian. Finally, he considers them situated in two different meridians. These four cases may become equally important; because, if it is determined that there are only two magnetic poles, and that these poles change their situations, it may some time hereafter be discovered that they pass through all the different positions.

Since the needle of the compass ought always to be in the plane which passes through the place of observation and the two magnetic poles, the problem is reduced to the discovery of the angle contained between this plane and the plane of the meridian. M. Euler, after having examined the different cases, finds, that they also express the earth’s magnetism, represented in the chart published by Mess. Mountaine and Dodson in 1744, particularly throughout Europe and North America, if the following principles are established.

Between the Arctic pole and the magnetic pole 14° 53´.

Between the Antarctic pole and the other magnetic pole 29° 23´.

53° 18´ The angle at the north pole, formed by the meridians passing through the two magnetic poles.

250° The longitude of the meridian, which passes over the northern magnetic pole.

As the observations which have been collected with regard to the variation are, for the most part, loose and inaccurate, it is impossible to represent them all with precision; and the great variations observed in the Indian ocean, seem to require, says M. Euler, that the three first quantities should be 14, 35, and 63 degrees. In the mean time, the general agreement is sufficiently satisfactory.

The high reputation of Dr. Halley’s magnetical chart renders it more particularly necessary to point out the errors contained therein[56]. There is evidently too little distance between the lines of no variation, of which one crosses the equator 17° westward of London, and the other 119° to the eastward. This makes 136 degrees only; whereas it should necessarily exceed 180 and even 200, inasmuch as the pole of the world is supposed farther distant from the magnetic pole towards the south than in the north, as is required by the other phænomena. Again, upon the coasts discovered by _Diemen_, there was no variation in 1642; and Dr. Halley also supposes there was none in 1700. Meanwhile, by the alteration observed at Paris, the line of no variation should be advanced 60° towards the south, which will agree better with the calculations, and prove that the distance of the two intersections was really greater than Dr. Halley had established.

The table of variation of Mess. Mountaine and Dodson is accompanied with several interesting particulars, which equally deserve to be inserted here.

At Barbadoes, (says Capt. Snow) the variation seems very nearly at a stand; for in the road I observed 5° east; and by Dr. Halley’s draught, in the year 1701, 5½ degrees. In 1747, at Port Royal keys, Jamaica, I observed the variation 7° 20´ E.; and on the coast of Carthagena, the same week, off the high land of Santa Martha, 7° 45´ nearly south of Port Royal. Therefore these curves are not much altered: the curve at Jamaica is nearly at a stand, as though tied, and the south part of them with the rest dropping to the westward.

Under the equator, in longitude 40° E. from London, the highest variation during the whole fifty-six years appears to be 17°¼ W. and the least 16°½ W.: and in latitude 15° N. longitude 60° W. from London, the variation has been constantly 5° E.: but in other places the case has been widely different. For in the latitude of 10° S. longitude 60° E. from London, the variation has decreased from 17° W. to 7°¼ W.; and in latitude 10° S. longitude 5° W. from London, from 2°¼ W. to 12°¾ W.; and in latitude 15° N. longitude 20°, it has increased from 1° W. to 9° W.

But there is still a more extraordinary appearance in the Indian seas. For instance, under the equator:

LONGITUDE│ MAGNETICAL VARIATION
East from│ in 1700. in 1756.
London. │
Degrees. │ Degrees. Degrees.
40│ 16¾ West. 16¼ West.
45│ 17¾ W. 14½ W.
50│ 17½ W. 11¾ W.
55│ 16½ W. 8¾ W.
60│ 15¼ W. 6 W.
65│ 13½ W. 4½ W.
70│ 11½ W. 3¼ W.
75│ 9¾ W. 1 W.
80│ 7¾ W. 0¼ East.
85│ 5½ W. 1¼ E.
90│ 4¼ W. 1 E.
95│ 3¼ W. 0½ West.
100│ 2½ W. 1 W.

Where the west variation, in the longitude 40° E. is the same in both the above years; and in 1700 the west variation seemed to be regularly decreasing from longitude 50° E. to the longitude 100° E.; but in 1756, we find the west variation decreasing so fast, that we have east variation in the longitude 80°, 85°, and 90° E.; and yet in the longitude 95° and 100° E. we have west variation again. _Philosophical Transactions for the year 1757._

To these remarks may be subjoined the following extracts from the _Exposition du calcul astronomique_, by _M. de la Lande_.

At the royal observatory in Paris, a magnetical needle of four inches deviated from the N. 18° 10´ towards the west, on the 15th of February 1759: and on the 22d of April 1760, the same needle varied 18° 20´. It is indeed natural to conceive, that nothing can be precisely ascertained by ten minutes upon a circle whose diameter is only four inches. It is nevertheless sufficiently evident, that this variation continues to increase at Paris. In 1610 the needle declined 8° towards the east, so that the variation has changed 26° 20´ in the space of 150 years; and this appears particularly since 1740: for the same needle, which has always been used by M. Maraldi, is more than 3° advanced towards the west, beyond what it was at that period; and this makes 9´ in one year.

_To_ VEER _and haul_, to pull a rope tight, by drawing it in and slackening it alternately, till the body to which it is applied acquires an additional motion, like the increased vibrations of a pendulum, so that the rope is straitened to a greater tension with more facility and dispatch. This method is particularly used in hauling the _bowlines_.

The wind is said to veer and haul when it alters its direction, and becomes more or less _fair_. Thus it is said to veer aft and to haul forward.

_To_ VEER _away the cable_. See CABLE.

VEERING, _virer vent arriere_, the operation by which a ship, in changing her course from one board to the other, turns her stern to windward. Hence it is used in opposition to _tacking_, wherein the head is turned to the wind, and the stern to _leeward_.

Thus the ship A, fig. 8. plate XI. having made the necessary dispositions to veer, _bears away_ gradually before the wind, till it blows obliquely upon the opposite side, which was formerly to leeward, as at _a_; and as the stern necessarily yields to this impression of the wind, assisted by the force of the helm, and the action of the waves upon the same quarter, the side which was formerly to leeward soon becomes to windward, as in the point _a_.

Since, by this movement, a ship loses ground considerably more than by tacking, it is rarely practised except in cases of necessity or delay: as, when the violence of the wind and sea renders tacking impracticable; or when her course is slackened to wait for a pilot, or some other ship in company, &c.

It has been observed in the article TACKING, _that the change of motion in any body, will be in proportion to the moving force impressed, and made according to the right line in which that force operates_. Hence it is evident, that veering as well as tacking is a necessary consequence of the same invariable principle; for as, in the latter, almost the whole force of the wind and of the helm are exerted on the hind part of the ship, to turn the prow to windward; so, in the former, the same impression, assisted by the efforts of the helm, falls upon the prow, to push it to leeward; and the motion communicated to the ship must in both cases necessarily conspire with the action of the wind.

Thus, when it becomes necessary to veer the ship, the sails towards the stern are either furled, or _brailed_ up, and made to _shiver_ in the wind; whilst those near the head are spread abroad, so as to collect the whole current of air which their surfaces can contain. Hence, while the whole force of the wind is exerted on the fore part of the ship to turn her about, its effect is considerably diminished, or altogether destroyed, on the surfaces of the after-sails. The fore part accordingly yields to the above impulse, and is put in motion; and this movement, conspiring with that of the wind, pushes the ship about as much as is necessary to produce the effect required. When she is turned so that the wind will act upon that quarter which was formerly to leeward, as at the point _a_, fig. 8. her circular motion will be accelerated by extending some of the sails near the stern, as the mizen, and by placing those at the prow more obliquely, which will wheel the vessel round with her bow to the windward; in the same situation, with regard to the wind, as when _close-hauled_, or tacking.

When the tempest is so violent as to prevent the use of sails, the effort of the wind operates almost equally on the opposite ends of the ship, so that the masts and yards situated at the head and stern counterbalance each other. The effect of the helm is also considerably diminished, because the _head-way_, which gives life and vigour to all its operations, is at this time feeble and ineffectual. Hence it is necessary to defray this equilibrium which subsists between the masts and yards _afore_ and _abaft_, and to throw the balance forward, in order to prepare for veering. This is accordingly performed by bracing the foremost yards across the direction of the wind, and arranging those on the main-mast and mizen mast directly in the line of the wind. If this expedient proves unsuccessful, and it is absolutely necessary to veer, in order to save the ship from destruction, by oversetting or running ashore, the mizen-mast must instantly be cut away, and even the main-mast, if she yet remains incapable of answering the helm by bearing away before the wind.

VENT. See the articles _Cannon_ and _Windage_.

VESSEL, _batiment_, a general name given to the different sorts of ships which are navigated on the ocean, or in canals and rivers. It is, however, more particularly applied to those of the smaller kind, furnished with one or two masts.

It has already been remarked in the article SHIP, that the views of utility, which ought always to be considered in a work of this kind, seemed to limit our general account of shipping to those which are most frequently employed in European navigation. We have therefore collected into one point of view the principal of these in plate XII.; so that the reader who is unacquainted with marine affairs, may the more easily perceive their distinguishing characters, which are also more particularly described under the reflective articles.

Thus fig. 4. plate XII. exhibits a snow under sail; fig. 5. represents a ketch at anchor; fig. 6. a brig or brigantine; fig. 7. a bilander; fig. 8. a xebec; fig. 9. a schooner; fig. 10. a galliot; fig. 11. a dogger; all of which are under sail; fig. 12. & 13. two galleys, one of which is under sail, and the other rowing; and fig. 14. a sloop.

The ketch, whose sails are furled, is furnished with a try-sail, like the snow; and it has a fore-sail, fore-staysail, and jib, nearly similar to those of a sloop; but the sails on the main-mast and mizen-mast are like those of a ship. The main-sail and main-topsail of the brig are like those of the schooner; and the fore-mast is rigged and equipped with sails in the same manner as the ship and snow. The sails, masts, and yards of the xebec, being extremely different from these, are described at large under the article. In the schooner both the mainsail and foresail are extended by a _boom_ and _gaff_, as likewise is the sloop’s mainsail; the sails of the dogger and galliot are sufficiently expressed in the plate; and, finally, the galleys are navigated with lateen-sails, which are extremely different from those of the vessels above described.

_Agent_ VICTUALLER. See AGENT VICTUALLER.

_To_ UNBALLAST, _delester_, to discharge the ballast of a ship.

UNBENDING, _désamarrer_, generally implies the act of taking off the sails from their yards and stays; of casting loose the anchors from their cables, or of untying one rope from another. See also _Bend_.

UNBITTING, _débitter_, the operation of removing the turns of a cable from off the bits. See BITS and CABLE.

_To_ UNDER-RUN, _parcourir_, to pass under or examine any part of a cable or other rope, in order to discover whether it is damaged or intangled.

It is usual to under-run the cables in particular harbours, as well to cleanse them with brooms and brushes from any filth, ooze, shells, &c. collected in the stream; as to examine whether they have sustained any injury under the surface of the water; as, from rocky ground, or by the friction against other cables or anchors.

_PLATE. XII_ _to face VESSEL_
]

_To_ UNDER-RUN _a tackle_, is to separate the several parts of which it is composed, and range them in order, from one block to the other; so that the general effort may not be interrupted, when it is put in motion.

UNDER SAIL, the state of a ship when she is loosened from her moorings, and under the government of her sails and rudder. See HELM and SAIL.

UNLACING, _déboutonner_, the act of loosening and taking off the _bonnet_ of a sail from its principal part.

_To_ UNMOOR, _desafourcher_, is to reduce a ship to the state of _riding_ by a single anchor and cable, after she has been _moored_ or fastened by two or more cables. See the articles ANCHOR and MOORING.

UNREEVING, the act of withdrawing or taking out a rope from any channel through which it had formerly passed; as in a _block_, _thimble_, _dead-eye_, &c. See REEVE.

_To_ UNRIG _a ship_, _défuner_, is to deprive her of the standing and running _rigging_.

VOYAL, _tournevire_, a large rope used to unmoor, or heave up the anchors of a ship, by transmitting the effort of the _capstern_ to the cables.

This is performed by fastening one part of the voyal to the cable in several places, and by winding another part thereof three or four times about the capstern, which answers the same purpose as if the cable itself were in that manner wound about the capstern; and the voyal being much lighter and more pliant, is infinitely more convenient in this exercise. See the articles CAPSTERN and NIPPER.

If the cable is drawn into the ship by the main capstern, the voyal is used without any block: but if the capstern in the fore-part of the ship be employed for this purpose, the voyal usually passes through a large block attached to the main-mast; and thence communicates with the jear-capstern.

UPPER-DECK, the highest of those decks which are continued throughout the whole of a ship of war, or merchantman, without any interruption, of steps or irregular ascents. See DECK and WAIST.

UPPER-WORK, _oeuvres mortes_, a general name given to all that part of a ship which is above the surface of the water when she is properly balanced for a sea-voyage: hence it may be considered as separated from the bottom by the main _wale_, as explained particularly in the article _Naval_ ARCHITECTURE.

UPRIGHT, the situation wherein the opposite sides of a ship are equally elevated above the surface of the water, as in fig. 2. plate VI.; or when she neither inclines to the right nor left, with regard to the vertical position of her stem and stern-post.

USES AND CUSTOMS _of the sea_; certain general principles which compose the basis of marine jurisprudence, and regulate the affairs of commerce and navigation.

W.

WAD, _bourrelet_, a quantity of old rope-yarns rolled firmly together into the form of a ball, and used to confine the shot or shell, together with its charge of powder, in the breech of a piece of artillery.

M. Le Blond observes, in his Elements of war, that the wad is necessary to retain the charge closely in the chamber of the cannon, so that it may not, when fired, be dilated around the sides of the ball, by its _windage_ as it passes through the chace; a circumstance which would considerably diminish the effort of the powder. But as the wad cannot be fastened to the sides of the bore, it is carried away in the same instant when the charge is inflamed, and that with so little resistance, that it cannot in any degree retard the explosion, or give time for the entire inflammation of the powder.

This reasoning may with equal propriety be applied to the wad that covers the bullet; which, nevertheless, is absolutely requisite, to prevent it from rolling out when the piece is fired horizontally or pointed downwards. Both are therefore peculiarly necessary in naval engagements, because, without being thus retained in its chamber, the shot would instantly roll out of the chace by the agitation of the vessel.

WAFT, _berne_, a signal displayed from the stern of a ship for some particular purpose, by hoisting the ensign, furled up together into a long roll, to the head of its staff. It is particularly used to summon the boats off from the shore to the ship whereto they belong; or as a signal for a pilot to repair aboard. See SIGNAL.

WAIST, that part of a ship which is contained between the quarter-deck and fore-castle, being usually a hollow space, with an ascent of several steps to either of those places.

When the waist of a merchant-ship is only one or two steps of descent from the quarter-deck and fore-castle, she is said to be galley-built; but when it is considerably deeper, as with six or seven steps, she is called frigate-built. See the articles DECK, DEEP-WAISTED, and FRIGATE.

WAKE, _houaiche_, the print or track impressed by the course of a ship on the surface of the water. It is formed by the re-union of the body of water, which was separated by the ship’s bottom whilst moving through it and may be seen to a considerable distance behind the stern, as smoother than the rest of the sea. Hence it is usually observed by the compass, to discover the angle of LEE-WAY.

A ship is said to be in the wake, _dans l’eau_, of another, when she follows her on the same track, or on a line supposed to be formed on the continuation of her keel. Thus the ships _a_ _b_, fig. 11. and _a_ _b_, fig. 7. plate V. are all in the wake of the foremost _b_. See the article LINE.

Two distant objects observed at sea are called in the _wake_ of each other, when the view of the farthest is intercepted by the nearest; so that the observer’s eye and the two objects are all placed upon the same right line.

WALE-KNOT, or WALL-KNOT, a particular sort of large knot raised upon the end of a rope, by untwisting the _strands_, and interweaving them amongst each other. See the article KNOT.

WALE-REARED, an obsolete phrase, implying _wall-sided_, which see.

WALES, _preceintes_, an assemblage of strong planks extending along a ship’s side, throughout her whole length, at different heights, and serving to reinforce the decks, and form the curves by which the vessel appears light and graceful on the water.

As the wales are framed of planks broader and thicker than the rest, they resemble ranges of hoops encircling the sides and _bows_. They are usually distinguished into the main-wale and the channel-wale; the breadth and thickness of which are expressed by Q and R in the MIDSHIP-FRAME, plate VII. and their length is exhibited in the ELEVATION, plate I. where L Q Z is the main-wale, and D R X the channel-wale, parallel to the former.

The situation of the wales, being ascertained by no invariable rule, is generally submitted to the fancy and judgment of the builder. The position of the gun-ports and scuppers ought, however, to be particularly considered on this occasion, that the wales may not be wounded by too many breaches.

WALL-SIDED, the figure of a ship’s side, when, instead of being incurvated so as to become gradually narrower towards the _upper part_, it is nearly perpendicular to the surface of the water, like a wall; and hence the derivation of the phrase.

WALT, an obsolete or spurious term signifying _crank_. See that article.

WARP, a small rope employed occasionally to remove a ship from one place to another, in a port, road, or river. And hence,

_To_ WARP, _remorquer_, is to change the situation of a ship, by pulling her from one part of a harbour, &c. to some other, by means of warps, which are attached to buoys; to anchors sunk in the bottom; or to certain stations upon the shore, as posts, rings, trees, &c. The ship is accordingly drawn forwards to those stations, either by pulling on the warps by hand, or by the application of some purchase, as a tackle, windlass, or capstern, upon her deck. See those articles.

When this operation is performed by the ship’s lesser anchors, these machines, together with their warps, are carried out in the boats alternately towards the place where the ship is endeavouring to arrive: so that when she is drawn up close to one anchor, the other is carried out to a competent distance before her, and being sunk, serves to fix the other warp by which she is farther advanced.

Warping is generally used when the sails are _unbent_, or when they cannot be successfully employed, which may either arise from the unfavourable state of the wind, the opposition of the tide, or the narrow limits of the channel.

WASH. See the article OAR.

WASH-BOARD, a broad thin plank fixed occasionally on the top of a boat’s side, so as to continue the height thereof, and be removed at pleasure. It is used to prevent the sea from breaking into the vessel, particularly when the surface is rough, as in tempestuous weather.

WATCH, _quart_, the space of time wherein one division of a ship’s crew remains upon deck, to perform the necessary services, whilst the rest are relieved from duty, either when the vessel is under sail, or at anchor.

The length of the sea-watch is not equal in the shipping of different nations. It is always kept four hours by our British seamen, if we except the _dog_-watch between four and eight in the evening, that contains two reliefs, each of which are only two hours on deck. The intent of this is to change the period of the night-watch every twenty-four hours; so that the party watching from eight till twelve in one night, shall watch from midnight till four in the morning on the succeeding one. In France the duration of the watch is extremely different, being in some places six hours, and in others seven or eight; and in Turky and Barbary it is usually five or six hours.

A ship’s company is usually classed into two parties; one of which is called the starboard and the other the larboard watch. It is, however, occasionally separated into three divisions, as in a _road_ or in particular voyages.

In a ship of war the watch is generally commanded by a lieutenant, and in merchant-ships by one of the mates; so that if there are four mates in the latter, there are two in each watch; the first and third being in the larboard, and the second and fourth in the starboard watch: but in the navy the officers who command the watch usually divide themselves into three parts, in order to lighten their duty.

WATCH-GLASSES, _horloge_, a name given to the glasses employed to measure the period of the watch, or to divide it into any number of equal parts, as hours, half-hours, &c. so that the several stations therein may be regularly kept and relieved; as at the _helm_, _pump_, _look-out_. &c.

_To set the_ WATCH, is to appoint one division of the crew to enter upon the duty of the watch; as at eight o’clock in the evening. Hence it is equivalent to _mounting the guard_ in the army. See the French term BORDÉE.

WATER-BORNE, the state of a ship, with regard to the water surrounding her bottom, when there is barely a sufficient depth of it to float her off from the ground; particularly when she had for some time rested thereon.

For _Dead_-WATER, _Foul_ WATER, and _High_-WATER, see DEAD, FOUL, and HIGH.

WATER-LINES, _lignes d’eau_, certain horizontal lines supposed to be drawn about the outside of a ship’s bottom, close to the surface of the water in which she floats. They are accordingly higher or lower upon the bottom, in proportion to the depth of the column of water required to float her. See a particular account of these in the article _Naval_ ARCHITECTURE.

In order to conceive a clearer idea of the curves of those lines when represented on a plane, let us suppose a ship laid _upright_ on a level ground; so that the keel shall lie in the same position, with respect to the horizon, as when she is laden. We may then describe several black horizontal lines about her bottom, which may be whitened for that purpose.

If a spectator is supposed to be placed, at a competent depth, under the middle of her bottom, in a line perpendicular to the plane of the ground; he will then, viewing the bottom upwards, discover the horizontal curves of all the water-lines.

These curves are all delineated on a plane, supposed to be formed by an horizontal section of the bottom, at the height of the load-water-line, _ligne d’eau du vaisseau chargé_.

WATER-LOGGED, the state of a ship when, by receiving a great quantity of water into her hold, by leaking, &c. she has become heavy and inactive upon the sea, so as to yield without resistance to the efforts of every wave rushing over her decks. As, in this dangerous situation, the center of gravity is no longer fixed, but fluctuating from place to place, the stability of the ship is utterly lost: she is therefore almost totally deprived of the use of her sails, which would operate to overset her, or press the head under water. Hence there is no resource for the crew, except to _free_ her by the pumps, or to abandon her by the boats as soon as possible.

WATER-SAIL, a small sail spread occasionally under the lower studding-sail, or driver-boom, in a fair wind, and smooth sea.

WATER-SHOT. See the article MOORING.

WATER-SPOUT, an extraordinary and dangerous meteor, consisting of a large mass of water, collected into a sort of column by the force of a whirlwind, and moved with rapidity along the surface of the sea.

A variety of authors have written on the cause and effects of these meteors, with different degrees of accuracy and probability. As it would be superfluous to enter minutely into their various conjectures, which are frequently grounded on erroneous principles, we shall content ourselves with selecting a few of the latest remarks; and which are apparently supported by philosophical reasoning.

Dr. Franklin, in his physical and meteorological observations, supposes a water-spout and a whirlwind to proceed from the same cause, their only difference being, that the latter passes over the land, and the former over the water. This opinion is corroborated by _M. de la Pryme_, in the _Philosophical Transactions_; where he describes two spouts observed at different times in Yorkshire, whose appearances in the air were exactly like those of the spouts at sea; and their effects the same as those of real whirlwinds.

Whirlwinds have generally a progressive as well as a circular motion; so had what is called the spout at _Topsham_, described in the _Transactions_; and this also by its effects appears to have been a real whirlwind. Water-spouts have also a progressive motion, which is more or less rapid; being in some violent, and in others barely perceptible.