The Sailor's Word-Book Part 253

VAPOUR, OR SMOKE. In polar parlance, a peculiar but natural result of the conversion of water into ice, which is too often supposed to indicate open water.

VARIABLES. Those parts of the sea where a steady wind is not expected.

VARIABLE STARS. Those which are found to exhibit periodical fluctuations of brightness; of which Algol and Mira Ceti are notable examples.

VARIATION. A term applied to the deviation of the magnetic needle or compa.s.s, from the true north point towards either east or west; called also the _declination_. The variation of the needle is properly defined as the angle which a magnetic needle suspended at liberty makes with the meridian line on a horizontal plane; or an arc of the horizon, comprehended between the true and the magnetic meridian. (_See_ ANNUAL VARIATION.)

VARIATION CHART. The well-known chart produced by Halley, whereon a number of curved lines show the variation of the compa.s.s in the places they pa.s.s through. The admiralty variation chart has been brought to great perfection.

VARIATION OF THE MOON. An inequality in the movement of our satellite, amounting at certain times to 37' in longitude: it was the first lunar inequality explained by Newton on the principles of gravitation.

VARIATION OF THE VARIATION. Is the change in the declination of the needle observed at different times in the same place.

VEDETTE. One or two cavalry soldiers stationed on the look-out.

VEER, TO. To let out, to pay out, to turn or change. Also, to veer or wear, in contradistinction from tacking. In tacking it is a necessary condition that the s.h.i.+p be brought up to the wind as close-hauled, and put round against the wind on the opposite tack. But in veering or wearing, especially when strong gales render it dangerous, unseamanlike, or impossible, the head of the vessel is put away from the wind, and turned round 20 points of the compa.s.s instead of 12, and, without strain or danger, is brought to the wind on the opposite tack. Many deep-thinking seamen, and Lords St. Vincent, Exmouth, and Sir E. Owen, issued orders to wear instead of tacking, when not inconvenient, deeming the accidents and wear and tear of tacking, detrimental to the sails, spars, and rigging.

VEER A BUOY IN A s.h.i.+P'S WAKE, TO. To slack out a rope to which a buoy has been attached, and let it go astern, for the purpose of bringing up a boat, or picking up a man who may have fallen overboard.

VEER AND HAUL, TO. To gently tauten and then slacken a rope three times before giving a heavy pull, the object being to concentrate the force of several men. The wind is said to veer and haul when it alters its direction; thus it is said, to veer aft, and haul forward.

VEER AWAY THE CABLE, TO. To slack and let it run out.

VEERING CABLE, THE. That cable which is veered out in unmooring, and not unspliced or unshackled in clearing hawse.

VEGA. a Lyrae. The bright lucida of the old northern constellation Lyra.

VEIN. The clear water between the openings of floes of ice. The same as _ice-lane_. Also, a very limited current of wind--a cat's-paw.

VELOCITY. In naval architecture, designing for velocity is giving that form to a s.h.i.+p's body by which she will pa.s.s through the water in the quickest s.p.a.ce of time.

VELOCITY OF TIDE OR CURRENT, depends on several circ.u.mstances. First, the tide varies with the state of the moon, running strongest at the springs, and the force of the ebb is much increased by rains, land freshes, &c. The currents also vary, especially when wind and tide combine to accelerate their action.

VENDAVAL [Sp. south wind, _tiempo di vendavales_]. A stormy time on the coast of Mexico, in the autumn, with violent thunder, lightning, and rain.

VENDUE MASTER. A commercial and marine auctioneer.

VENE-SEANDES. The old commercial term for Venetian sequins.

VENT. In artillery, the small aperture near the breech by which the fire of the priming is communicated to the charge.

VENT-BIT. A peculiar augur or screw gimlet used for clearing the vent of a gun when obstructed.

VENT-FIELD OF A GUN. The raised tablet in the metal near the breech in which the vent is bored.

VENTILATOR. The name of various machines contrived to expel the foul air from the store-rooms and hold, and introduce fresh in its stead.

VENT-PIECE. The movable fitment which closes the breech and contains the vent in Armstrong breech-loading guns.

VENT-PLUG. A fid or stopple made of leather or oak.u.m fitting in the vent of a piece to stop it against weather, &c.

VENTRAL FIN. The posterior pair of fins under the body of fishes, corresponding to the hind legs of terrestrial quadrupeds.

VENUS. One of the inferior planets, and the second in order of distance from the sun. (_See_ TRANSIT OF VENUS.)

VERIFICATION OF s.h.i.+P'S PAPERS. In this necessary process it is declared that papers of themselves prove nothing, and require to be supported by the oaths of persons in a situation to give them validity.

VERITAS. A register of s.h.i.+pping established in Paris, on the principle of Lloyd's List.

VERNAL EQUINOX. The point where the sun crosses the equator, going north. It is opposite the place of the autumnal equinox. (_See_ EQUINOXES.)

VERNIER, OR NONIUS. A graduated scale for the measurement of minute divisions, especially on the arcs of astronomical instruments, s.e.xtants, &c. The thousandth part of a degree can be taken by the naked eye; the ten thousandth by a microscope.

VERSED SINE. In geometry, is the part of the radius intercepted between the arc and its sine.

VERTEX. The zenith, the point overhead; the apex of a conical mountain.

VERTICAL ANGLES. Opposite angles made by two lines cutting or crossing each other, and are always equal. (_See_ ANGLE OF THE VERTICAL.)

VERTICAL CIRCLES. Great circles of the sphere intercepting each other in the zenith and nadir, and cutting the horizon at right angles.

VERTICAL FIRE. In artillery, that directed upward at such an angle as that it will fall vertically, or nearly so, to its destination. It includes all elevations above 30, though the most usual is 45. It is very effective with sh.e.l.ls; but with small b.a.l.l.s, as proposed by Carnot and others, who have ill reckoned the r.e.t.a.r.dation by the atmosphere, it is insignificant.

VERTICAL FORCE. The centre of displacement is also that of the centre of vertical force that the water exerts to support the immersed vessel.

Also, the dip of the magnetic needle, measured by vibrations of the dipping needle over certain arcs, and referable to some fixed position, as Greenwich, where corresponding observations with the same needle have been previously, as well as subsequently, made.

VERTICAL PLAN. _See_ ORTHOGRAPHIC PROJECTION.

VERTICITY. The tendency of the loadstone to point towards the magnetic north and south.

VESSEL. A general name for all the different sorts of s.h.i.+ps, boats, &c., navigated on the ocean or on rivers and ca.n.a.ls.

VETAYLE. An archaism for victuals.

VIA LACTEA. That well-known irregular luminous band, stretching across the sky from horizon to horizon: it consists of myriads of small stars, and has pa.s.sed under the names of Milky Way, Galaxy, Jacob's Ladder, Watling-strete, &c.

VICE-ADMIRAL. The rank in the fleet next to that of an admiral; he carries his flag at the fore.

VICE-ADMIRALTY COURTS. Branches of the High Court of Admiralty, inst.i.tuted for carrying on the like duties in several of our colonies, prize-courts, &c. (_See_ ADMIRALTY, HIGH COURT OF.)

VICE-CONSUL. An officer appointed in sea-ports to aid the consul in affairs relating to merchant vessels. If there be a resident consul, the vice-consul is appointed and paid by him. Vice-consuls wait on commanders, consuls on captains, captains on consuls-general--the naval authority providing boats.

VICE-NAIL. A screw.

VICTUALLER. A vessel which carries provisions. In the early age of the navy, each man-of-war had a victualler especially attached to her; as, in Henry VIII.'s reign, we find the _Nicholas Draper_, of 140 tons and 40 men, was victualler to the _Trinity Sovereign_; the _Barbara_ of Greenwich to the _Gabriel Royal_, and so on.

VICTUALLING-BILL. A custom-house doc.u.ment, warranting the s.h.i.+pment of such bonded stores as the master of an outward-bound merchantman may require for his intended voyage.

VICTUALLING-BOOK. A counterpart of the s.h.i.+p's open list, which is kept by the purser, to enable him to make the necessary entries in it.