CYCLOPEAN BUILDINGS. The works constructed of large stones are called by this name and also Megalithic. See PELASGIC.

CYLINDER. (Gr. Kuλidpov.) A solid whose base is a circle, and whose curved surface is everywhere at an equal distance from the axis or line supposed to pass through its middle. Its formation may be conceived to be generated by the revolution of a rectangular parallelogram about one of its sides. The cone, sphere, and cylinder have a remarkable relation to each other, first discovered by Archimedes, namely, that the cone is one third the cylinder having the same base and altitude; and the inscribed sphere two thirds of the cylinder; or the cone, sphere, and cylinder are to each other as the numbers 1, 2, 3. It is termed a right cylinder when the axis is at right angles to the base, but if at an oblique angle the cylinder is said to be oblique.

Table of the areas of cylinders from 9 to 15 inches diameter:

NOTE. The areas of cylinders are as the squares of their diameters.

CYLINDRICAL CEILING OF VAULTING. Vulgarly called a waggon-head and cradle. One in the shape of the segment of a cylinder. This form appears to have been first used by the Romans. It admits of being pierced by lunettes for the admission of light, which form cylindro-cylindric arches, and is usually formed into panels or coffers.

CYLINDRICAL WORK. Any kind of work which partakes of the shape of a cylinder, of whatever material it be formed.

CYLINDROID. A solid which differs from a cylinder in having ellipses instead of circles for its ends or bases.

CYMA. (Gr. Kuua, a wave.) A moulding taking its name from its contour resembling that of a wave, being hollow in its upper part and swelling below. Of this moulding there are two sorts, the cyma recta thus, just described, and the cyma reversa thus, wherein the upper part swells, whilst the lower is hollow. By workmen, each called an ogee.

CYMATIUM. (Gr.) The name commonly applied to the upper moulding of a cornice or capping.

CYMBIA. The same as FILLET.

CYPRESS. (Lat. Cupressus.) The wood of the cypress was valued for its hardness and durability by the ancient architects.

CYZICENUS. In ancient architecture, a large hall decorated with sculpture. See GLYPTO

THECA.

D

DABBING, DAUBING, OF PITCHING. Working the face of a stone after it has been broached and draughted, with a pick-shaped tool or the patent axe, so as to form a series of minute holes.

DADO. The die, or that part of the pedestal of a column between the base and the cornice. It is of a cubic form, whence the name of die. Large rooms are sometimes decorated with a base, dado, and cornice, representing a pedestal, and the term dado is often applied to the whole. See BASE.

DAGHOBA OF DAGOBA. The Eastern topes or tumuli mostly contained relics, the worship of these objects being one of the principal characteristics of Budhism. These were designated dagobas, of which the word "pagoda" appears to be a corruption. In a Budhist temple, the dagoba is a structure which occupies the place of an altar in a Christian church. It consists of a low circular basement or drum surmounted by a hemispherical or elliptical dome that supports a square block covered by a roof called a tee. DAIRY. An apartment in a house, or a separate building, for the preservation of milk, and the manufacture of it into butter, cheese, or other dairy produce. When on a small scale, where the milk is only used for butter, the dairy may be a room on the north side of the dwelling, or form one of the offices connected with the kitchen court. The temperature of a dairy should be within the range of forty-eight to fifty-five degrees of Fahrenheit, with sufficient ventilation to discharge all smells and impurities of the air. A dairy on a large scale should be a detached building, in which case it should contain a milk-room, a churning-room, and a dairy scullery or place for scalding the utensils.

If cheese be to be made, a room is required for the cheese-press, and another for drying and storing the cheeses.

DAIS. (Fr.) The platform or raised floor at the upper end of a dining-hall, where the high table stood; also the seat with a canopy over it, for the chief guests who sat at the high table.

DAMP COURSE. In order to prevent the damp rising up the walls from the soil on which a house is built, a course of some impermeable material is laid on the foundation walls a short distance (about a foot) above the level of the outside soil. This damp course, as it is called, is formed of a layer of powdered charcoal mixed with pitch or resin and powdered pitcoal; or of two courses of slates set in cement; of asphalte; or of the stoneware hollow tile manufactured for this purpose. DAMPNESS. A moisture generally attendant on buildings finished hastily on account of the materials not being dry; or the walls not being made of good well-burnt bricks; or with bad mortar; or the joints not flushed up, and allowing wet to come through. DANCETTE. The chevron, or zigzag moulding, in Norman architecture. See fig. 1381. DAY or BAY. In Gothic architecture, the compartment in windows formed by the transoms or horizontal pieces and mullions or vertical pieces.

DEAD SHORE. A piece of timber worked up in brickwork to support a superincumbent mass until the brickwork which is to carry it has set or become hard.

DEAFENING SOUND-BOARDING. The pugging used to prevent the passage of sound through wooden partitions. See BOARDING.

DEAL. (Sax. Delan, to divide.) Properly the small thickness of timber into which a piece of any sort is cut up; but the term is now, though improperly, restricted in its signification to the wood of the fir tree cut up into thicknesses in the countries whence deals are imported, viz. Christiania, Dantzic, &c. Their usual thickness is three inches, and their width nine. They are purchased by the hundred, which contains 120 deals, be their thickness what it may, reduced by calculation to a standard thickness of one inch and a half and to a length of twelve feet. Whole deal is that which is one inch and a quarter thick, and slit deal is half that thickness. See BOARD. DECAGON. (Gr. Aexa, ten, and гavia, an angle.)

A geometrical figure having ten sides

and ten angles. If the sides and angles are all equal, the figure is a regular decagon, and capable of being inscribed in a circle.

DECASTYLE. See COLONNADE.

DECIMAL. (Lat.) A term applied to a system of arithmetic in which the scale of numbers proceeds by tens.

DECIMAL EQUIVALENTS OF INCHES, FEET, AND YARDS; AND OF A SHILLING.

10000

DECORATED PERIOD. A term applied to the Medieval architecture in England prevailing during the reigns of the three first Edwards, wherein the decorative features grew out of, or became embodied in, and formed part of, the construction. It succeeded to the Early English period.

DECORATION. The combination of ornamental objects which the desire for varying a form or forms brings together in many ways for embellishing those subjects which are the objects of art.

DEDICATION CROSS. See CROSs, fig. 1392.

DELIQUIE. (Lat.) A term used by Vitruvius to designate the rafters which formed the ridge of the roof and threw the water on each side.

DENSITY. (Lat. Densus, thick.) A term used in physics to denote the quantity of matter which a body contains under a given or determinate surface; for example, a cubic foot. The quantity of matter in a body is called its mass, and is measured by the weight of the body, to which it is always proportional; hence the density of a body is great in proportion as its weight is great and its volume small; or the density of bodies is directly as their masses, and inversely as their volumes.

DENTILS OF DENTELS. (Lat. Dentes, teeth.) The small square blocks or projections in the bed mouldings of cornices in the Ionic, Corinthian, Composite, and occasionally Doric orders; their breadth should be half their height; and, as Vitruvius teaches, the interval (METOCHE) between them two thirds of their breadth. In the Grecian orders they are not used under modillions.

DEODORISATION AND DISINFECTION. The Summary of the "Hastings Prize Essay, 1865," on these subjects, states that:-I. For the sick room, free ventilation, when it can be secured, together with an even temperature, is all that can be required. II. For rapid deodorisation and disinfection, chlorine is the most effective agent known. steady and continuous effect, ozone is the best agent known. IV. In the absence of ozone, iodine exposed in the solid form to the air, is the best. V. For that of fluid and III. For semi-fluid substances undergoing decomposition, iodine is the best. deodorisation and disinfection of solid bodies that cannot be destroyed, a mixture of powdered chloride of zinc or powdered sulphate of zinc, with sawdust, is the best. VI. For the After this, a mixture of carbolic acid and sawdust, ranks next in order; and following on that, wood ashes. VII. For that of infected articles of clothing, etc., exposure to heat at 212° Fahr. is the only true method. And, VIII. For the deodorisation and disinfection of substances that may be destroyed, heat to destruction is the true method. Carbolic acid, Condy's fluid, Burnett's fluid, and Charcoal are among the materials manufactured for this purpose.

DERBY OF DARBY. A two-handed float used in plasterers' work. DESCRIPTION OF A BUILDING. The same as SPECIFICATION. DESCRIPTIVE GEOMETRY. That which consists in the application of geometrical rules to the representation of the figures, and the various relations of the forms of bodies, according to certain conventional forms. It differs from perspective, on account of the representation being made in such a manner that the exact distance between the different points of the body represented can always be found, and consequently all the mathematical relations resulting from the form and position of the body may be deduced from the representation.

DESIGN. (Lat. Designo.) The idea formed in the mind of an artist on any particular subject, which he transfers by some medium, for the purpose of making it known to others. Every work of design is to be considered either in relation to the art that produced it, to the nature of its adaptation to the end sought, or to the nature of the end it is destined to serve; hence its beauty is dependent on the wisdom or excellence displayed in

the design, on the fitness or propriety of the adaptation, and upon the utility for the end. See COMPOSITION.

DETAILS. A term usually applied to the drawings on a large scale for the use of builders, and generally called working drawings.

DETERMINING LINE. In the conic sections, a line parallel to the base of the cone; in the hyperbola this line is within the base; in the parabolic sections it forms a tangent to the base, in the elliptic it falls without it. In the intersecting line of a circle, the determining line will never meet the plan of the base to which it is parallel. DIACONICUM. A place contiguous to the ancient churches, wherein were preserved the sacred vestments, vessels, relics, and ornaments of the altar. In modern language, the sacristy. The sacristy is now also called the vestry.

DIAGONAL. (Gr. Aia, through, and Twvia, angle.) A straight line drawn through a figure joining two opposite angles. The term, in geometry, is used in speaking of four-sided figures, but it is nevertheless properly applied with reference to all polygons whereof the number of sides is not less than four. The term diameter is used by Euclid in the same sense; but modern geometers use the term diameter only in speaking of curve lines, and diagonal when speaking of angular figures.

DIAGONAL SCALE. A compound scale formed by vertical and horizontal subdivisions with diagonals drawn across them, whereby very small parts can be measured off by means of equidistant parallels crossing others of the same kind.

DIAGRAM. (Gr. Alaypauua, from Aia, through, and гpapw, I write.) The figure or scheme for the illustration of a mathematical or other proposition.

DIAMETER. (Gr. Aia, through, and Merpov, a measure.) A straight line passing through the centre of a geometrical figure, as that of a circle, ellipse, or hyperbola. The term is architecturally used to express the measure across the lower part of the shaft of a column, and is usually divided into sixty parts called minutes, which form the scale for the measurement of all the parts of an order. See DIAGONAL.

DIAMICTON. The Roman method of building a wall, with regular ashlar work on the outsides and filled in with rubble between. It is similar to Emplecton, but without the diatoni or binding stones which go through the thickness of the walls, showing on both sides. See MASONRY.

DIAMOND PAVEMENT. One disposed in squares arranged diagonally.
DIAPER WORK. The face of

stone worked into squares or lozenges, with a leaf therein; as over arches and between bands. It is generally done only in interior work for decorating a plain surface. The illustration (fig. 1398) is from Canterbury Cathedral, and of the Perpendicular period. DIASTYLE. (Gr. Διa and Στυλος, a column.) That distance between columns which consists of three diameters, or, according to some, of four diameters. The term is sometimes used adjectively, to signify that the building is arranged with those intervals between the columns. DIATONI. (Gr. Δια and Toros, an extension.) In Greek architecture, the stones of a wall wrought on two faces,

which, from stretching beyond the stones above and below them, that is, going through the wall, made a good bond or tie to the work.

DIAZOMA. (Gr. Aia through, and Zwua, a cincture.) In ancient architecture, the landings or resting places which, at different heights, encircled the amphitheatre like so many bands or cinctures, whence the name.

DICASTERIUM. (Gr. Akn, justice.) In ancient architecture, the name of a tribunal or hall of justice.

DICTYOTHETON. (Gr. AIKTUOV, a net, and Tienu, I place.) In ancient architecture, masonry worked in courses, like the meshes of a net. Also open lattice-work, for admitting light and air.

DIDORON. (Gr.) See BRICK.

DIE OF A PEDESTAL. That part included between the base and the cornice. See DADO. DIGGING. In soft ground, one man with a spade will throw up, per hour, a cubic yard of twenty-seven feet. If a mattock must be used, the same quantity will require two men, and in a strong gravel, three. It will require three men to wheel thirty cubic yards of gravel in a day to the distance of twenty yards.

DIGLYPH. (Gr. Ais, twice, and rauw, I carve.) A projecting face or femur, with two panels or channels called glyphs, sunk thereon. See TRIGLYPH.

DILAPIDATION. The state of neglect into which a building has been permitted to fall. DIMENSION. (Lat. Dimetior.) In geometry is either length, breadth, or thickness. Thus a line has one dimension, as of length; a superficies has two, length and breadth; a solid has three dimensions, length, breadth, and thickness.

DIMINISHED ARCH. One lower or less than a semicircle, called by the French voute surbaissée. See SURBASED ARCH.

DIMINISHED BAR OF A SASH. One thinner on the edge towards the room than on that towards the glass of the window.

DIMINISHED COLUMN. A column whereof the upper diameter is less than the lower. DIMINISHING RULE. A board cut with a concave edge, so as to ascertain the swell of a column, and to try its curvature.

DIMINISHING SCALE. A scale of gradation used in finding the different points for drawing the spiral curve of the Ionic volute, by describing the arc of a circle through every three preceding points, the extreme point of the last arc being one of the next three. Each point through which the curve passes is regulated so as to be in a line drawn to the centre of the volute and the lines at equal angles with each other.

DIMINUTION OF A COLUMN. The continued contraction of the diameter of the column as it rises. Most of the modern authors make the diminution to commence from one-third the height of the column; but in all the ancient examples the diminution commences from the bottom of the shaft. See ENTASIS. In Gothic architecture neither swell nor diminution is used, all the horizontal sections being similar and equal. DINING OR DINNER ROOM. Generally one of the largest rooms in a dwelling-house. In large buildings it extends to forty or fifty feet in length, and the breadth is from half to three-fourths the length. In middle-sized houses, dining-rooms run from twenty-four down to eighteen feet in length by eighteen to sixteen feet in width, and thirteen or fourteen feet in height.

DIOCLETIAN WINDOW. Usually called a VENETIAN WINDOW.

DIPTERAL. (Gr. ATTEpos, double-winged.) In ancient architecture, a temple having a double range of columns on each of its flanks. See TEMPLE.

DIRECT RADIAL. In perspective, a right line from the eye perpendicular to the picture. DIRECTING LINE. In perspective, the line in which an original plane would cut the directing plane.

DIRECTING PLANE. In perspective, a plane passing through the point of sight, or the eye, parallel to the picture.

DIRECTING POINT. In perspective, that in which any original line produced cuts the directing plane.

DIRECTOR OF AN ORIGINAL LINE. In perspective, the straight line passing through the directing point and the eye of a spectator.

DIRECTOR OF THE EYE. In perspective, the intersection of the plane with the directing plane perpendicular to the original plane and that of the picture, and hence also perpendicular to the directing and vanishing planes, since each of the two latter is parallel to each of the two former.

DIRECTRIX. In geometry, the name given to a certain straight line perpendicular to the axis of a conic section. One of the properties of these curves is that the distance of any point of the curve from the directrix is to the distance of the same point from the focus in a constant ratio. The name is sometimes applied generally to any straight or curved line required for the description of any curve.

DISCHARGE. (Fr. Décharger.) The relief given to a beam, or any other piece of timber, too much loaded by an incumbent weight of building. When the relief is given, the weight is said to be discharged.

DISCHARGING ARCH. An arch built over a wood lintel, whereby the bearing upon it is taken off. The chords of discharging arches are not much longer than the lintel, being the segments of very large circles. A temporary arch is frequently introduced, and removed on completing the building. Sometimes the arches are built without any lintel under them.

DISHING OUT. The same as CRADLING.

DISPLUVIATUM. (Lat.) In ancient architecture, a place from which the rain is conveyed away in two channels. According to Vitruvius, a cavædium displuviatum was an open court exposed to the rain.