are at the greatest and the least distance from the sun, and are termed higher or lower accordingly. The two are joined by a diameter called the line of the apsides.
AQUAGE. The old law-term denoting the toll paid for water-carriage.
AQUARIUS. The eleventh sign in the zodiac (α Aquarius Sadalmelik).
AQUATIC. Inhabiting or relating to the water.
AQUATILE. An archaism for aquatic; thus Howell's lexicon describes the crocodile as "partly aquatil, partly terrestrial."
AQUATITES. The law-term for everything living in the water.
AQUE. Wall-sided flat-floored boats, which navigate the Rhine.
AQUEDUCT. Conduits or canals built for the conveyance of water.
AQUILA. The constellation Aquila, in which α Aquilæ is an important star of the first magnitude: used by seamen in determining the latitude and longitude; also in lunar distances. (See Altair.)
AQUILON. The north-east wind, formerly much dreaded by mariners.
ARAMECH. The Arabic name for the star Arcturus.
ARBALIST [from arcus and balista]. An engine to throw stones, or the cross-bow used for bullets, darts, arrows, &c.; formerly arbalisters formed part of a naval force.
ARBITER. The judge to whom two persons refer their differences; not always judicial, but the arbiter, in his own person, of the fate of empires and peoples.
ARBITRAGE. The referring commercial disputes to the arbitration of two or more indifferent persons.
ARBITRATION. The settlement of disputes out of court.
ARBOR. In chronometry, a shaft, spindle, or axis.
ARBY. A northern name for the thrift or sea-lavender.
ARC, or Arch. The segment of a circle or any curved line, by which all angles are measured.
ARC DIURNAL. See Diurnal Arc.
ARC NOCTURNAL. See Nocturnal Arc.
ARC OF DIRECTION or Progression. The arc which a planet appears to describe when its motion is direct or progressive in the order of the signs.
ARC OF VISION. The sun's depth below the horizon when the planets and stars begin to appear.
ARCH-BOARD. The part of the stern over the counter, immediately under the knuckles of the stern-timbers.
ARCH OF THE COVE. An elliptical moulding sprung over the cove of a ship, at the lower part of the taffrail.
ARCHED SQUALL. A violent gust of wind, usually distinguished by the arched form of the clouds near the horizon, whence they rise rapidly towards the zenith, leaving the sky visible through it.
ARCHEL, Archil, Orchill. Rocella tinctorum fucus, a lichen found on the rocks of the Canary and Cape de Verde groups; it yields a rich purple. Litmus, largely used in chemistry, is derived from it.
ARCHES. A common term among seamen for the Archipelago. (See also Galley-arches.)
ARCHI-GUBERNUS. The commander of the imperial ship in ancient times.
ARCHIMEDES' SCREW. An ingenious spiral pump for draining docks or raising water to any proposed height—the invention of that wonderful man. It is also used to remove grain in breweries from a lower to a higher level. The name has been recently applied to the very important introduction in steam navigation—the propelling screw. (See Screw-propeller.)
ARCHING. When a vessel is not strongly built there is always a tendency in the greater section to lift, and the lower sections to fall; hence the fore and after ends droop, producing arching, or hogging (which see).
ARCHIPELAGO. A corruption of Aegeopelagus, now applied to clusters of islands in general. Originally the Ægean Sea. An archipelago has a great number of islands of various sizes, disposed without order; but often contains several subordinate groups. Such are the Ægean, the Corean, the Caribbean, Indian, Polynesian, and others.
ARCHITECTURE. See Naval Architecture.
ARCTIC. Northern, or lying under arktos, the Bear; an epithet given to the north polar regions comprised within the arctic circle, a lesser circle of the sphere, very nearly 23° 28′ distant from the north pole.
ARCTIC OCEAN. So called from surrounding the pole within the imaginary circle of that name.
ARCTIC POLE. The north pole of the globe.
ARCTURUS. α Boötis. A star of the first magnitude, close to the knee of Arctophylax, or Boötes. One of the nautical stars.
ARD, or Aird. A British or Gaelic term for a rocky eminence, or rocks on a wash: hence the word hard, in present use. It is also an enunciation.
ARDENT. Said of a vessel when she gripes, or comes to the wind quickly.
ARE. The archaism for oar (which see). A measure of land in France containing 100 square metres.
AREA. The plane or surface contained between any boundary lines. The superficial contents of any figure or work; as, the area of any square or triangle.
ARENACEOUS. Sandy; partaking of the qualities of sand; brittle; as, arenaceous limestone, quartz, &c.
ARENAL. In meteorology, a cloud of dust, often so thick as to prevent seeing a stone's-throw off. It is common in South America, being raised by the wind from adjoining shores. Also off the coast of Africa at the termination of the desert of Zahara.
ARENATION. The burying of scorbutic patients up to the neck in holes in a sandy beach, for cure; also spreading hot sand over a diseased person.
AREOMETER. An instrument for measuring the specific gravity of fluids.
ARGIN. An old word for an embankment.
ARGO. A name famous from Jason's romantic expedition, but absurdly quoted as the first ship, for the fleets of Danaus and Minos are mentioned long before, and the Argo herself was chased by a squadron under Æetes.
ARGO NAVIS. The southern constellation of the Ship, containing 9 clusters, 3 nebulæ, 13 double and 540 single stars, of which about 64 are easily visible. As most of these were invisible to the Greeks, the name was probably given by the Egyptians.
ARGOL. The tartaric acid or lees adhering to the sides of wine-casks, particularly of port-wine; an article of commerce; supertartrate of potass.
ARGOLET. A light horseman of the middle ages.
ARGONAUTA. The paper-nautilus. The sail which it was supposed to spread to catch the wind, is merely a modified arm which invests the outer surface of the shell.
ARGONAUTS. A company of forty-four heroes who sailed in the Argo to obtain the golden fleece; an expedition which fixes one of the most memorable epochs in history. Also
