the catacaustic and the diacaustic; the former being caused by reflection, and the latter by refraction.

CAVEDIUM. (Lat.) In ancient architecture an open quadrangle or court within a house. The cavædia described by Vitruvius are of five species: Tuscanicum, Corinthium, Tetrastylon (with four columns), Displuviatum (uncovered), and Testudinatum (vaulted). Some authors have made the cavædium the same as the atrium and vestibulum, but they were essentially different.

CAVE. (Lat. Cavum.) A hollow place. Perhaps the oldest species of architecture on record.

CAVEE. (Lat.) In ancient architecture the subterranean cells in an amphitheatre, wherein the wild beasts were confined in readiness for the fights of the arena. In the end the amphitheatre itself (by synecdoche) was called cavea, in which sense it is employed by Ammianus Marcellinus, lib. xxix. cap. i.

CAVETTO. (Lat. Cavus.) A hollowed moulding, whose profile is the quadrant of a circle. It is principally used in cornices.

CEDAR. (Gr. Kedpos.) The pinus cedrus of Linnæus, a forest tree little used in this country, except for cabinet work. See p. 484.

CEILING. (Lat. Coelum.) The upper horizontal or curved surface of an apartment opposite the floor, usually finished with plastered work. The subject of ceilings is treated of at length in Sect. 22. Chap. I. Book III. CEILING FLOOR. The joisting and ceiling supported by the beams of the roof. CEILING JOISTS. Small beams, which are either mortised into the sides of the binding joists, or notched upon and nailed up to the under sides of those joists. The last mode diminishes the height of the room, but is more easily executed, and is by some thought not so liable to break the plaster as when the ends of the ceiling-joists are inserted into pulley mortises. CELER.

See ARCHITECTS, list of, 42.

CELL. (Lat. Cella.) In ancient architecture the part of a temple within the walls. It was also called the naos, whence our nave in a church. The part of a temple in front of the cell was called the pronaos, and that in the rear the posticum.

CELLAR. (Fr. Cellier.) The lower story of a building, when wholly or partly under the level of the ground.

CEMENT. (Lat. Cementum.) The medium through which stones, bricks, or any other materials are made to adhere to each other. The different cements for stones and bricks, the most important in building, are treated of in Book II. Chap. II. Sect. 10. CELTIC ARCHITECTURE. See Book I. Chap. II. Sect. 1.

CEMETERY. (Gr. Ketual, I lie dead.) An edifice or area where the dead are interred. The most celebrated public cemeteries of Europe are those of Naples, of that in the vicinity of Bologna, of Pisa, and of the more modern ones of Paris, whereof that of Père la Chaise is the principal. That of Pisa is particularly distinguished by the beauty of its form and architecture, which is of early Italian Gothic. It is 490 feet long, 170 feet wide, and 60 feet high, cloistered round the four sides.

CENOTAPH. (Gr. Kevos, empty, and Tapos, a sepulchre.) A monument erected to the memory of a person buried in another place. CENTERING. The temporary woodwork or framing whereon any vaulted work is constructed, sometimes called a centre. The principle upon which centering is constructed will be found under the heads of MECHANICAL CARPENTRY, Book II. Chap. I. Sect. 11. and of PRACTICAL CARPENTRY, Book II. Chap. III. Sect. 4. CENTRE. (Lat. Centrum.) In a general sense denotes a point equally remote from the extremes of a line, superficies, or body, or it is the middle of a line or plane by which a figure or body is divided into two equal parts; or the middle point so dividing a line, plane, or solid, that some certain effects are equal on all its sides. For example, in a circle the centre is every where at equal distance from the circumference; in a sphere the centre is a point at the same distance from every point in the surface. CENTRES OF A DOOR. The two pivots on which the door revolves.

CENTROLINEAD. An instrument for drawing lines converging to a point at any required distance, whether accessible or inaccessible.

CEROMA. (Gr.) An apartment in the Gymnasia and baths of the ancients, where the bathers and wrestlers were anointed with oil thickened by wax, as the name imports. CESSPOOL, or SESSPOOL. A well sunk under the mouth of a drain to receive the sediment which might choke up its passage.

CHAIN TIMBERS. See BOND.

CHALCIDICUM. (Lat.) In ancient architecture a term used by Vitruvius to denote a large building appropriated to the purpose of administering justice, but applied sometimes to the tribunal itself. According to Festus, the name is derived from Chalcis, a city in Eubœa.

CHALK. (Germ. Kalk.) Earthy carbonate of lime, found in abundance in Great Britain,

and, indeed, in most parts of the world. It is insoluble in water, but decomposed by heat, and sometimes used in masonry for the same purposes as limestone. CHAMBER. (Fr. Chambre.) Properly a room vaulted or arched, but the word is now generally used in a more restricted sense to signify an apartment appropriated to lodging. With the French the word has a much more extensive meaning; but with us the almost only use of it, beyond what is above stated, is as applied in a palace to the room in which the sovereign receives the subject, which room is called the Presence Chamber.

CHAMBER OF A LOCK. In canals the space between the gates in which the vessels rise and sink from one level to another, in order to pass the lock.

CHAMBER STORY. That story of a house appropriated for bed-rooms. In good houses it should never be less than ten feet high, in better houses from twelve feet to fifteen feet.

CHAMBERS. See ARCHITECTS, list of, 300.

CHAMBRANLE. (Fr.) An ornamental bordering on the sides and tops of doors, windows, and fireplaces. This ornament is generally taken from the architrave of the order of the building. In window frames the sill is also ornamental, forming a fourth side. The top of a three-sided chambranle is called the transverse, and the sides ascendants.

CHAMFER. (Fr. Chamfrein.) The arris of anything originally right-angled cut a slope or bevel, so that the plane it then forms is inclined less than a right angle to the other planes with which it intersects.

CHAMPAIN LINE. In ornamental carved work formed of excavations is the line parallel to the continuous line, either ascending or descending.

CHANCEL. That part of the eastern end of a church in which the altar is placed. See CANCELLI. This is the strict meaning; but in many cases the chancel extends much further into the church, the original divisions having been removed for accommodating a larger congregation. The word is also used to denote a separate division of the ancient basilica, latticed off to separate the judges and council from the audience part of the place. CHANDRY. An apartment in a palace or royal dwelling for depositing candles and other lights. CHANNEL. (Fr. Canal.) A long gutter or canal sunk below the surface of a body. CHANNEL OF THE LARMIER. See CANAL OF THE LARMIER.

CHANNEL OF THE VOLUte. See CANAL OF THE VOLUTE.

CHANNEL STONES. In paving are those prepared for gutters or channels, serving to collect and run off the rain water with a current.

CHANTRY. (Lat. Cantaria.) A little chapel in ancient churches with an endowment for one or more priests to say mass for the release of souls out of purgatory. In the fourteenth year of Edward VI. all the chantries in England were dissolved: at this period there were no less than forty-seven attached to St. Paul's Cathedral. CHAPEL. (Lat. Capella.) A building for religious worship, erected separately from a church, and served by a chaplain. In Catholic churches, and in cathedrals and abbey churches, chapels are usually annexed in the recesses on the sides of the aisles. These are also called chantries.

CHAPITER. The same as CAPITAL, which see.

CHAPLET. (Fr. Chapelet.) A moulding carved into beads, olives, and the like.
BAGUETTE.

CHAPTER HOUSE.

See

In ecclesiastical architecture the apartment (usually attached) of a cathedral or collegiate church in which the heads of the church or the chapter meet to transact business.

CHAPTREL. (Fr.) The same as IMPOST, which see.

CHARGED. A term used to denote that one member of a piece of architecture is sustained by another. A frieze is said to be charged with the ornament cut on it. CHARNEL HOUSE. A place where the bones of the dead are deposited.

CHARTOPHYLACIUM.

writings.

A recess or apartment for the preservation of records or valuable

CHASE. An upright indent cut in a wall for the joining another to it, so as to hide light and exclude air.

CHASE MORTISE, or PULLEY MORTISE. A long mortise cut lengthwise in one of a pair of parallel timbers, for the insertion of one end of a transverse timber, by making the latter revolve round a centre at the other end, which is fixed in the other parallel timber. This may be exemplified in ceiling joists where the binding joists are the parallel timbers first fixed, and the ceiling are the transverse joists. See PRACTICAL CARPENTRY, in the body of the work.

CHEEKS. Two upright, equal, and similar parts of any piece of timber-work. Such, for instance, as the sides of a dormer window.

CHEEKS OF A MORTISE are the two solid parts upon the sides of the mortise.

The thick

ness of each cheek should not be less than the thickness of the mortise, except mouldings on the stiles absolutely require it to be otherwise. CHEESE ROOM. A room set apart for the reception of cheeses after they are made. The walls should be lined, and fitted up with shelves with one or more stages, according to the size of the room, and proper gangways for commodious passage. In places where much cheese is manufactured, the dairy-room may be placed below, the shelf-room directly above, and lofts may be built over the shelf-room, with trap doors through each floor. This will save much carriage, and will be found advantageous for drying the cheeses.

CHEQUERS. In masonry, are stones in the facings of walls, which have all their thin joints continued in straight lines, without interruption or breaking joints. Walls built in this manner are of the very worst description; particularly when the joints are made horizontal and vertical. Those which consist of diagonal joints, or joints inclined to the horizon, were used by the Romans.

CHESNUT OF CHESTNUT. The fagus castanea. A forest tree used in building. See p. 483. CHEST. The same as caisson, which see.

CHEVRON WORK. A zigzag ornament used in the archivolts of Saxon and Norman arches (see fig. 188.). The outline of chevron work is a conjunction of right lines of equal lengths alternately disposed so as to form exterior and interior angles, and at the same time having all the angular points in the same straight line, or in the same curve line when the chevron work is used for ornamenting arches. CHICHELE. See ARCHITECTS, list of, 146.

CHIMNEY. (Fr. Cheminée.) The place in a room where a fire is burnt, and from which the smoke is carried away by means of a conduit, called a flue. Chimneys are usually made by a projection from a wall, and recess in the same from the floor ascending within the limits of the projection and the recess. That part of the opening which faces the room is properly called the fireplace, the stone or marble under which is called the hearth. That on a level with and in front of it is called the slab. The vertical sides of the opening are called jambs. The head of the fore-plate resting on the jambs is called the mantel, and the cavity or hollow from the fireplace to the top of the room is called the funnel. The part of the funnel which contracts as it ascends is termed the gathering, by some the gathering of the wings. The tube or cavity, of a parallelogrammatic form, on the place from where the gathering ceases, up to the top of the chimney, is called the flue. The part between the gathering and the flue is called the throat. The part of the wall facing the room, and forming one side of the funnel parallel thereto, or the part of the wall forming the sides of the funnels where there are more than one, is the breast. In external walls, that side of the funnel opposite the breast is called the back. When there is more than one chimney in the same wall, the solid parts that divide them are called withs : and when several chimneys are collected into one mass, it is called a stack of chimneys. The part which rises above the roof, for discharging the smoke into the air, is called a chimney shaft, whose horizontal upper surface is termed the chimney-top.

The covings were formerly placed at right angles to the face of the wall, and the chimney was finished in that manner; but Count Rumford showed that more heat is obtained from the fire by reflection when the covings are placed in an oblique position. He likewise directed that the fire itself should be kept as near to the hearth as possible, and that the throat of the chimney should be constructed much narrower than had been practised, with the view of preventing the escape of so much heated air as happened with wide throats. If the throat be too near the fire, the draught will be too strong, and the fuel will be wasted; if it be too high up, the draught will be too languid, and there will be a danger of the smoke being occasionally beat back into the room. CHIMNEY PIECE. See Book III. Chap. I. Sect. 22.

CHINESE ARCHITECTURE. See Book I. Chap. II. Sect. 8.

CHIP.

A piece of any material cut by an acute-angled instrument. CHIROSOPHUS. See ARCHITECTS, list of, 7.

CHISEL.

An instrument used in masonry, carpentry, and joinery, and also by carvers and statuaries, for cutting either by pressure or by impulse from the blows of a mallet or hammer. There are various kinds of chisels; the principal ones used in carpentry and joinery are the former, the paring chisel, the gouge, the mortise chisel, the socket chisel, and the ripping chisel.

CHISELED WORK. In masonry, the state of stones whose surface is formed by the chisel. CHIT. An instrument used for cleaving laths.

CHOIR. (Gr. Xopos.) The part of a church in which the choristers sing divine service. In former times it was raised separate from the altar, with a pulpit on each side, in which the epistles and gospels were recited, as is still the case in several churches on the Continent. It was separated from the nave in the time of Constantine. In nunneries, the choir is a large apartment, separated by a grate from the body of the church, where the nuns chaunt the service.

CHORAGIC MONUMENT. (Gr. Xopos.) In Grecian architecture, a monument erected in honour of the choragus who gained the prize by the exhibition of the best musical or theatrical entertainment at the festivals of Bacchus. The choragi were the heads of the ten tribes at Athens, who overlooked and arranged the games at their own expense. The prize was usually a tripod, which the victor was bound publicly to exhibit, for which purpose a building or column was usually erected. The remains of two very fine monuments of this sort, viz. of Lysicrates and Thrasyllus, are still to be seen at Athens. See p.69.

CHORD. In geometry, the straight line which joins the two extremities of the arc of a curve; so called from the resemblance which the arc and chord together have to a bow and its string, the chord representing the string.

CHRISMAS. See ARCHITECTS, list of, 263.

CHRISTOBOLO. See ARCHITECTS, list of, 154.
CHRYSES. See ARCHITECTS, list of, 63.

CHURCH. (Gr. Kupiakov, from Kupios, Lord.) A building dedicated to the performance of Christian worship. For the general principles on which churches are to be designed see Book III. Chap. III. Sect. 3., also in Book I. Chap. II. Sect. 14. From these latter it will be seen that the basilica were the first buildings used for the assembly of the early Christians. Among the first of the churches was that of St. Peter at Rome, about the year 326, nearly on the site of the present church; and it is supposed that the first church of St. Sophia at Constantinople was built somewhat on its model. That which was afterwards erected by Justinian seems, in its turn, to have afforded the model of St. Mark's at Venice, which was the first in Italy constructed with pendentives and a dome, the former affording the means of covering a square plan with an hemispherical vault. The four most celebrated churches in Europe erected since the revival of the arts are, St. Peter's at Rome, which stands on an area of 227,069 feet superficial; Sta. Maria del Fiore at Florence, standing on 84,802 feet; St. Paul's, London, which stands on 84,025 feet, and St. Geneviève at Paris, 60,287 feet. The churches on the Continent

are usually ranged under seven classes: pontifical, as St. Peter's, where the pope occasionally officiates; patriarchal, where the government is in a patriarch; metropolitan, where an archbishop is the head; cathedral, where a bishop presides; collegiate, when attached to a college; parochial, attached to a parish; and conventual when belonging to a convent. In this country the churches are cathedral, abbey, and parochial.

CIBORIUM. (KI6wpiov.) An insulated erection open on each side with arches, and having a dome of ogee form carried or supported by four columns. It is also the coffer or case in which the host is deposited.

CICCIONE. See ARCHITECTS, list of, 158.

CILERY. The drapery or foliage carved on the heads of columns.

CILL. (Sax. Cill.) The timber or stone at the foot of a door, &c.

Ground cills are the

timbers on the ground which support the posts and superstructure of a timber building. The name of cill is also given to the bottom pieces which support quarter and truss partitions.

CIMBIA. A fillet string, list, or cornice.

CIMELIARCH.

A name given to the apartment where the plate and vestments are deposited

in churches. CINCTURE. The ring, list, or fillet at the top and bottom of a column, which divides the shaft of the column from its capital and base. CINQUEFOIL. An ornament used in the pointed style of architecture; it consists of five cuspidated divisions or curved pendents inscribed in a pointed arch, or in a circular ring applied to windows and panels. The cinquefoil, when inscribed in a circle, forms a rosette of five equal leaves having an open space in the middle, the leaves being formed by the open spaces, and not by the solids or cusps.

CIONE DI ORGAGNA. See ARCHITECTS, list of, 144.

CIPPUS. A small low column, sometimes without a base or capital, and most frequently bearing an inscription. Among the ancients the cippus was used for various purposes; when placed on a road it indicated the distance of places; on other occasions cippi were employed as memorials of remarkable events, as landmarks, and for bearing sepulchral epitaphs.

CIRCLE. (Lat. Circulus.) A figure contained under one line called the circumference, to which all lines drawn from a certain point within it, called the centre, are equal. It is the most capacious of all plain figures.

CIRCULAR BUILDINGS. Such as are built upon a circular plan. When the interior also is circular, the building is called a rotunda,

CIRCULAR WORK. A term applied to any work with cylindric faces.

CIRCULAR CIRCULAR, or CYLINDRO-CYLINDRIC WORK. A term applied to any work which is formed by the intersection of two cylinders whose axes are not in the same direction.

The line formed by the intersection of the surfaces is termed, by mathematicians, a line of double curvature.

CIRCULAR ROors. Those whose horizontal sections are circular.

CIRCULAR WINDING STAIRS. Such as have a cylindric case or walled enclosure, with the planes of the risers of the steps tending towards the axis of the cylinder. CIRCUMFEREnce. The boundary lines of a circular body.

CIRCUMSCRIBE. (Verb.) To draw a line around a figure, or enclose it so that the enclosed shall be touched on all its angles or on its whole circumference by the line or body that encloses it.

CIRCUMVOLUTIONS.

The turns in the spiral of the Ionic capital, which are usually three,

but there are four in the capitals of the temple of Minerva Polias. CIRCUS. (Lat.) In ancient architecture, a straight, long, narrow building, whose length to its breadth was generally as 5 to 1. It was divided down the centre by an ornamented barrier called the spina, and was used by the Romans for the exhibition of public spectacles and chariot races. Several existed at Rome, whereof the most celebrated was the Circus Maximus. Julius Cæsar improved and altered the Circus Maximus, and that it might serve for the purpose of a naumachia, supplied it with water. Augustus added to it the celebrated obelisk now standing in the Piazza del Popolo. Of this circus no vestiges remain. Besides these at Rome were the circi of Flaminius, near the Pantheon; Agonalis, occupying the site of what is now called the Piazza Navona; of Nero, on a portion whereof St. Peter's stands. Those of Antoninus and Aurelian, no longer even in ruins; but that of Caracalla, which was 738 feet in length, is at the present time sufficiently perfect to exhibit its plan and distribution in the most satisfactory manner. The spectacles of the circus were called the Circensian Games, and consisted of chariot and horse races, of both whereof the Romans were passionately fond, but particularly of the former, which in the times of the emperors excited so great an interest, as to divide the whole population of the city into factions, distinguished by the colours worn by the different charioteers. The disputes of these factions often led to serious distur

bances.

CISSOID. In geometry a curved line invented by Diocles. Its name is derived from Kiσσos, ivy, from the curve appearing to mount along its assymptote, as ivy climbs on the trunk of a tree. The curve consists of two infinite branches above and below the diameter of a circle, at one of whose ends a tangent being drawn, the curve approaches the tangent without ever meeting it. The curve was invented by its author with a view to the solution of the famous problem of the duplication of the cube, or the insertion of two mean proportionals between two given straight lines. Its mechanical construction may

be found in Newton's Arithmetica Universalis.

CIST. (Gr. Korn, a chest.) A term used to denominate the mystic baskets used in processions connected with the Eleusinian mysteries. It was originally formed of wicker work, and when afterwards made of metal, the form and texture were preserved in imitation of the original material. When sculptured on ancient monuments, it indicates some connection with the mysteries of Ceres and Bacchus.

CISTERN. (Gr. Korn.) A reservoir for water, whether sunk below or formed of planks of wood above ground. In the construction of an earthen cistern, a well-tempered stratum of clay must be laid as a foundation for a brick flooring, and the bricks laid in terras mortar of Parker's cement. The sides must be built with the same materials; and if in a cellar or other place near a wall a space must be filled with clay, from the foundation to the top of the cistern contiguous to the wall, by which means it will be preserved from injury. Cisterns above ground are usually formed of wooden planks and carried by bearers; but the cistern formed of slates, now much used, is the best for adoption.

CIVIL ARCHITECTURE. The art of erecting every species of edifice destined for the use of man, the several matters necessary to the knowledge whereof forms the subject of this work.

CIVIC CROWN. A garland of oak leaves and acorns, often used as an architectural or

nament.

CLAMP. In brick-making a large mass of bricks generally quadrangular on the plan, and six, seven, or eight feet high, arranged in the brick field for burning, which is effected by flues prepared in stocking the clamp, and breeze or cinders laid between each course of bricks. See Book II. Chap. II. sect 9.

CLAMP. In carpentry and joinery is a piece of wood fixed to another with a mortise and tenon, or a groove and tongue, so that the fibres of the piece thus fixed cross those of the other, and thereby prevent it from casting or warping.

CLAMP NAILS. See NAILS.

CLASP NAILS. See NAILS.

CLATHRI. In ancient Roman architecture, were bars of iron or wood which were used to secure doors or windows.