The name has also been given to an admixture of letters, as the initials of a name, engraved on a seal, plate, &c, so as to have an enigmatical appearance. These are plentiful on ancient tombs, gravestones, &c. It has also been used as the name of a disguised manner of writing, wherein such arbitrary characters are made use of as may be agreed on by two or more persons corresponding, to stand for letters or words, and which characters are supposed to be understood only by the persons agreeing to use them. This kind of writing has been extensively used in times of war, to conceal from the enemy the facts contained in any letters which they might intercept. This mode of writing gave rise to another art, that of deciphering, or reading letters written in cipher; and hence, also, the word cipher came to signify the key to unravel the characters of cipher-writing.

CIP'OLIN, an Italian marble, containing a slight admixture of quartz and oxide of iron. Its colour is green, with white zones. Name from Ital.cipollina, a shalot. CIPRIN'DE, the carp family of fishes. Type, Cyprindus, Lin.; Order, Malacopterygii abdominales, Cuv.; Genera, Cyprindus, Lin.; Cobitis, Lin.; Anableps, Blum.

curve at a certain point; called also the circle of equi-curvature.-Circles of the sphere; such circles as cut the mundane sphere, and have their circumference on its surface. They are either moveable or fixed. The first are those whose peripheries are in the moveable surface, and which therefore revolve with its diurnai motion, as the meridians, &c.; the latter have their peripheries in the moveable surface, and do not revolve, as the ecliptic, equator, and its parallels. The circles of the sphere are, besides, either great or little: a great circle divides it into two hemispheres, having the same centre and diameter with it as the horizon: a little or less circle divides the sphere into two unequal parts, having neither the same centre nor diameter with it as the parallels of latitude.- Circles of Altitude. See ALMUCANTAR. Circles of declination;

great circles intersecting each other in the poles of the world.-Circles of excursion; circles parallel to the ecliptic, and at such a distance from it (usually 10°) as that the excursions of the planets towards the poles of the ecliptic may be within them.-Circle of illumination; a circle passing through the centre of a planet perpendicular to a line drawn from the sun to the respective body. This is sup

CIRCLE, Lat. circulus, from circus. A geometrical figure contained under one line called the circumference; and is such, that all straight lines drawn from a certain point within the figure called the centre, to the circumference, are equal to one another. Thus, in the figure, AB AC AD. These are called radii of the circle, of which the line BD, passing through the centre, is the diameter.

The diameter of a circle is to its circumference nearly as 1 to 3, more nearly as 7 to 22, more nearly as 106 to 333, more nearly as 113 to 355, more nearly as 1702 to 5347, &c.; or, taking the diameter as 1, the circumference is

the unillumined part, which it does nearly. -Circles of latitude; great circles, called also secondaries of the ecliptic, perpendicular to the plane of the ecliptic, passing through the poles thereof, and through every star and planet. They are so called because they serve to measure the latitude of the stars, such latitude being simply the arc of one of the circles intercepted between the star and the ecliptic. -Circles of longitude; several lesser circles parallel to the ecliptic, diminishing in proportion as they recede from it on these arcs the longitude of the stars is reckoned.Circle of perpetual apparition; one of the lesser circles parallel to the equator, described by any point of the sphere touching the northern point of the horizon, and carried about with the diurnal motion. All the stars within this circle never set. Circle of perpetual occultation; a lesser circle parallel to the equator, and containing all those stars which never appear in our hemisphere. The stars situated between the circles of perpetual apparition and perpetual occultation, alternately rise and set at certain

times.

CITHAREX'YLUM, a genus of plants. Didynamia-Angiospermia. Fiddle-wood. There are five species, natives of the West Indies and warmer parts of America, where they grow to large trees. Name from zlaga, a harp, or a fiddle, and guλov, wood: the wood being particularly adapted for stringed musical instruments. CITRATE, a salt formed by the union of the citric acid with a salifiable base. CITRIC ACID, the acid of lemons. trus, a lemon.

CITRON, an agreeable fruit, the produce of the Citrus limonium, extensively cultivated at Madeira. It is a native of Asia. It differs from the lemon in being less acid.

CITRUS. KITgos. A genus of plants. Polyadelphia-Polyandria. This genus comprises the orange, lemon, citron, bergamotte, lime, and other trees. Warm climates.

CITY, Lat. civitas. A borough or town corporate, which is or has been the seat of a bishop, or the capital of his see: it differs in no other respect from another borough.

CIVET, an unctuous perfume taken from the civet-cat. It is worth, when genuine, from 30s. to 40s. an ounce.

CIVET-CAT, or CIVET. This name is common to all the species of the genus Viverra, but especially applied to the V. civetta, Lin., an animal of an ash-colour, irregularly barred and spotted with black, and not unlike a cat, but more closely resembling the fox. It inhabits the hottest parts of Africa. From the civet, and zibet (the Indian species), the perfume called civet is obtained. The name Civet is Arabic, zebet.

CIVIC CROWN, a garland of oak leaves which was given to a Roman soldier who had saved the life of a citizen (civicus.)

CIVIL ARCHITECTURE, the architecture which is employed for the purposes of civil life, in distinction from military and naval architecture.

CIVIL LAW, the law of a state, city or country; appropriately the Roman law comprised in the Institutes, Code, and Digest of Justinian, and the Novel Constitutions.

CIVIL LIST, the officers of civil government; also the revenue appropriated to support civil government.

CIVIL'IAN, one learned in civil or Roman law; particularly a member of the "College of Doctors of Law exercent in the Ecclesiastical and Admiralty Courts" in England and Wales.

CLAN. The Clans are tribes consisting of many families bearing the same surname, which, according to tradition, descend from a common ancestor.

CLARE-OBSCURE, light and shade in painting.

CLAR'ICHORD, from clarus, clear, and chorda, a string; a musical instrument in the form of a spinet; called also a manichord. It is furnished with about 50 keys and 70 strings, some of these being in unison. It is a great favourite in nunneries.

CLARION, from Fr. clairon, a wind instrument differing from the common trumpet in this, that its tube is narrower, and its tone more acute and shrill.

CLARIONET, dim. of clarion (q. v.).

CLA'RO-OBSCURO (clarus and obscura). In painting, the art of disposing advantageously the lights and shades of a piece. It also denotes a painting in two colours, as black and white.

CLASS, a term used to denote an assemblage of beings or things having some marked character in common. Classes are made up of orders. What the genus is to the species, or the order to the genera, the class is in respect to the orders. Every class comprehends part of the series of genera collected into several orders; every order is an assemblage of genera, every genus an assemblage of similar species, and every species is made up of homogeneous individuals.

CLASSIC. In the fine arts, such an arrangement of the subject that all the parts are suitable to the general design. In literature, signifies the highest and purest class of writers in any language.

CLAVATE, Lat. clavatus, club-shaped; applied to parts of plants.

CLA'VIARY, from clavis, a key; a scale of lines and spaces in music.

CLACK-VALVE, a valve much employed

RICHORD.

CLAVICOR'NE3, the fourth family of the pentamerous coleoptera. Name from

clava, a club, and cornu, a horn; clubhorned, the antennæ being always thicker at the extremity, and often clubshaped.

CLAVUS (Lat.), a nail. An excrescence from the grains of rye. Also a parasitical fungus, termed spermedia clavus. Also a severe pain in the forehead like the driving of a nail.

CLAW or UNGUIS, the narrow part at the base of a petal, which takes the place of the foot-stalk of a leaf.

CLAY, a name common to all unctuous tenacious earths. The common clays generally consist of about equal parts of alumina and silica, with various impurities. Pure clay is alumina (q. v.). Potters'

clay consists of about equal parts of alu

have against him, as found in his draw. Balances are then struck from all the accounts, and the claims transferred from one to another, until they are so wound up and cancelled, that each clerk has only to settle with two or three others, and their balances are immediately paid.

CLEAT, from zλulgov, a fastener; a piece of wood used in a ship to fasten ropes upon. Cleats are of different shapes; some have one arm, some two, or are simply hollow in the middle to receive a rope, and are called belaying-cleats, a deck-cleat, and a thumb-cleat.

CLEAVAGE, a term applied to the mechanical division of crystals, by showing the direction in which their lamina can

CLAYES, plu., from Fr. claie, a hurdle; a sort of fortification, consisting of wattles or hurdles made with stakes interwoven with osiers to cover lodgments.

CLAY'ING, the operation of puddling. CLAY'SLATE, argillaceous schist; the argillite of Kirwan. It is an indurate clay common to the fossiliferous and metamorphic series. Usual colours, bluish-grey and greyish-black, of various shades. Constituents, silica about 50 per cent.; alumina 25; magnesia 10 or 12, with some metallic oxides, potash, sulphur, and carbon. It occurs in great beds, and is extensively quarried for roofing and other

purposes.

CLAY'STONE, an earthy stone resembling indurated clay. It is a variety of prismatic felspar.

CLEAR. 1. To clear a ship at the Custom-House is to exhibit the documents required by law, give bonds to perform other acts requisite, and procure a commission to sail.-2. To clear the land is, in nautical language, to gain such a distance from shore as to have plenty of searoom.-3. To clear a ship for action is to remove all incumbrances and prepare for an engagement.

CLEARANCE, a certificate that a ship has been cleared at the custom-house. CLEAR'ING, among London bankers, a method adopted for exchanging the drafts of each other's houses. Thus at half-past 3 o'clock, a clerk from each banker attends at the clearing-house, where he brings all the drafts on the other bankers which have been paid into his house that day, and deposits them in their proper draws, (a draw being allotted to each banker); he then credits their accounts separately with the articles which they

of the mineral.

CLECHE. In heraldry, a kind of cross, charged with another cross of the same figure, but of the colour of the field.

CLEDGE. In mining, the upper stratum of fullers' earth.

CLEF. In music, a character placed at the beginning of a stave to determine the degree of elevation occupied by that stave in the system, and to point out the

names of all the notes contained in the

line of the clef.

CLEFT-GRAFT, a graft made by cleaving the stock, and inserting the cion. dria-Polygynia. Virgin's Bower. CLEMATIS, a genus of plants. PolyanBriName from zλnua, a tendril tish type, Traveller's Joy (C. vitalba).

CLEPSY'DRA, from sudga (from ATTW, to hide, and dag, water). An instrument used by the ancients to measure time, by the dropping of water through a hole from one vessel to another; also a chemical vessel perforated in the same manner.

CLEV'Y, the draught-iron of a plough, &c. CLEW. In nautical language, the lower corner of a square-sail, and the aftmost corner of a stay-sail.

CLEW-GARNETs, a sort of tackle of rope and pulley fastened to the clews of the main and fore-sails of a ship, to truss them up to the yard.

CLEW-LINES, a tackle similar to the clewgarnets, but applied to the smaller squaresails.

CLICKS, small pieces of iron falling into a notched wheel, attached to the winches in cutters, &c., and thereby serving the office of pawls.

CLIENT, from cliens. Anciently, one who put himself under the protection of a man of distinction, who became his patron: at present, one who puts himself

to the mercy of a lawyer, who often becomes his tormentor.

CLIMACTERIC, from zλpaž, a gradation. A term applied to certain years of a person's life, which are supposed to mark a certain degree in the scale of his existence, and also to a particular disease observed in persons advanced in life, wherein a general decay of the system takes place without any assignable cause being observed.

CLINAN'THUS, from zλn, a bed, and avlos, a flower. The enlarged and flattened top of a common peduncle, which supports several sessile flowers.

CLINCH. In nautical language, the part of a cable, or the kind of knot and seizings fastening it to the ring of an anchor, &c. CLINCH'ER, a cramp or piece of iron bent down to fasten anything.

CLINCH'ER-BUILT, made of clincher

work.

CLINCH'ER-WORK, the disposition of the planks; the side of any boat or vessel, when the lower edge of every plank overlays that next below it, like the slates on the roof of a house.

CLINCH'ING. 1. The operation of driving the point of a nail backward, when it has penetrated quite through a piece of wood. 2. The driving of a little oakum into the seams of a ship, to keep out the water; an imperfect kind of caulking. CLIN'IUM, used to denote the summit of a floral branch, of which the carpella are the termination.

CLINKERS, bricks impregnated with nitre, and more thoroughly burnt by being placed next to the fire in the kiln.

CLINK'STONE, phonolite, a felspathic rock of the trap family, named from its yielding a metallic sound when struck. CLINOMETER, from zλvw, to lean, and Mergov, measure. An instrument for measuring the dip of mineral strata. CLIO, a genus of Mollusks, order Pteropoda. The C. borealis, Lin., is the chief food of the whale.

CLITORIS, Autogis. A small glandiform body, above the nymphæ and before the opening of the urinary passage of females.

CLOA'CA, (Lat.) a common sewer. Used to designate the cavity formed by the extremity of the intestinal canal in birds, fish, reptiles, and the monotrematous animals.

CLOFF, that in which any goods are put for convenience of carriage; as the bags of pepper, hops, &c.

CLOISTER, claustrum. Literally an inclosed place. The principal part of a regular monastery, consisting of a square peristyle or piazza, between the church, the chapter-house, and the refectory, and over which is the dormitory.

CLOSE-HAULED, the trim of a ship's sails when she endeavours to make progress in the nearest direction possible towards that point of the compass from which the wind blows.

CLOSE-QUARTERS,

strong barriers of wood, used in a ship for defence when the ship is boarded.

CLOS'ER. In masonry, the last stone in the horizontal length of a wall, which is smaller than the rest to fill up the row.

CLOSE-STRING, in dog-leg stairs, a staircase without an open newel.

CLOUTED OF CLOTTED CREAM, produced on the surface of milk by setting a pan of new milk on a hot hearth.

CLOVE, a pungent aromatic spice, the fruit or rather calyces of the unopened flowers of the clove-tree. Cloves are shaped like a nail, whence their name, from Fr. clou, a nail. Clove is also the name given, 1. To 7lbs. of wool. 2. To 8lbs. of cheese or butter.

CLOVER, CLOVER-GRASS, a name common to all the species (about 100) of the genus Trifolium. Dutch, klaver, a club, quasi club-grass.

CLOVE-TREE, the Caryophyllus aromaticus, a native of the Molucca Islands. It grows to the size of the Laurel. CLUB-MOSS, a name common to all the species of the genus Lycopodium.

CLUMP. 1. A mass of trees or shrubs, or both, generally compact in its outline, and always small as compared with extensive plantations.-2. The compressed clay of coal strata.

CLUNCH, an indurate clay found dividing the coal-seams.

CLU'PEE (plural of clupea, a herring), the herring family of fishes. Type, genus Clupea.

CLYM'ENA, a genus of Articulata. Order Abranchiata, family Abranchiata setigera, Cuv. Name from zλuesvos, plain, their bodies having but few rings compared with the earth-worm.

CLY'PEATE, Lat. clypeus, shield-like. The same as scutate.

COADUNATE, a natural family of plants, which have a number of flowers clustered together (coadunatus) so as to resemble a single flower.

COAG'ULUM, Lat. the tenacious substance formed from a fluid by coagulation.

COAK, in the construction of wood framings, a small cylinder of hard wood, let into the ends of the pieces to be joined, to render the joining more secure. The several pieces forming the timbers of ships are at present coaked together: formerly they were chocked together by triangular chocks, made fast by tree-nails, which sustained all the stress at the joint in whatever direction; and, therefore,