POINTED ARCH. See p. 119, et seq.

POINTED ARCHITECTURE. See Book I. Chap. II. Sect. 15.

POINTING. The raking out the mortar from between the joints of brickwork, and replacing the same with new mortar.

POINTS OF SUPPORT. The points or surfaces on which a building rests. See p. 438.

POLISHING.

POLLAJOLO.

See MARBLE.

See ARCHITECTS, list of, 179.

POLLARD. A tree which has been frequently lopped or polled of its head and branches, a practice very injurious to good timber.

POLYGON. (Gr. Пoλus, many, and Favia, an angle.) A multilateral figure, or one whose perimeter consists of more than four sides and angles. If the sides and angles be equal the figure is called a regular polygon. Polygons are distinguished according to the number of the sides; thus those of five sides are called pentagons, those of six, heragons, those of seven, heptagons, and so on. The subjoined is a table of the areas and perpendiculars of polygons the side being =1.

From the above to find the area of a regular polygon, multiply one of the sides of the polygon by the perpendicular from the centre on that side, and multiply half the product by the number of sides; or, multiply the square of the given side of the polygon by the number opposite to its name under the word area.

POLYGRAM. (Gr.) A figure consisting of many lines.

POLYHEDRON. (Gr.) A solid contained under many sides or planes. If the sides of a polyhedron be regular polygons, all similar and equal, it becomes a regular body, and may be inscribed in a sphere, that is, a sphere may be drawn round it, so that its surface shall touch all the solid angles of the body.

POLYSTYLE. (Gr. Πολυs and Στυλος.)

Of many columns. See COLONNADE.

POMEL. (Lat. Pomum.) A globular protuberance terminating a pinnacle, &c.

PONTOON. (Fr.) A bridge of boats.

POORE. See ARCHITECTS, list of, 112.

POPLAR. (Lat. Populus.) A tree sometimes used in building. See p. 486.

PORCH. (Fr.) An exterior appendage to a building, forming a covered approach to one of its principal doorways.

PORPHYRY. (Gr.) A very hard stone, partaking of the nature of granite. It is not so fine as many of the ordinary marbles, but far exceeds them in hardness, and will take a very fine polish. It is still found in Egypt in immense strata. It is generally of a high purple, which varies, however, from claret colour to violet. Its variations are rarely disposed in grains. The red lead coloured porphyry, which abounds in Minorca, is variegated with black, white, and green, and is a beautiful and valuable material. The pale and red porphyry, variegated with black, white, and green, is found in Arabia Petræa and Upper Egypt, and in separate nodules in Germany, England, and Ireland. The sorts best known are what the Italians call the porfido rosso (red), which is of a deep red with oblong white spots; the latter are of feld spath, which resembles schorl. There are two varieties of black porphyry, the porfido nero, or black porphyry, and that called the serpentino nero antico. The first has a ground entirely black, spotted with oblong white spots like the red porphyry; the other has also a black ground with great white spots, oblong, or rather in the form of a parallelopipedon, nearly resembling in colour what the French call serpentin vert antique. The brown porphyry has a brown ground with large oblong greenish spots. There are several sorts of green porphyry, which the Italians principally distinguish by the names of serpentino antico verde, found in great abundance and in large blocks in the neighbourhood of the ancient Ostia, of a green ground with oblong spots of a lighter shade of the same colour; and the porfido verde, which is of a ground of very dark green, almost approaching to black, with lighter shades of a fine grass green. The art of cutting porphyry, as practised by the ancients, appears

to be now quite lost.

PORTAL. (Fr. Portail, from Lat. Porta.) The arch over a door or gate; the framework of the gate; the lesser gate, when there are two of different dimensions at one entrance. This term was formerly applied to a small square corner in a room separated from the rest of the apartment by wainscotting.

PORTCULLIS. (Fr.) A strong grated framing of timber, resembling a harrow, the vertical pieces whereof were pointed with iron at the bottom, for the purpose of striking into the ground when it was dropped, and also to break and destroy that upon which it fell. It was made to slide up and down in a groove of solid stone-work within the arch of the portals of old castles. Its introduction is supposed to have been in the early Norman castles. PORTICO. (Lat. Porticus.) See COLONNADE.

PORTLAND STONE. A dull white species of stone brought from the island of Portland, See p. 468, et seq.

PORTUGUESE Architecture.

POSITION.

See Book I. Chap. II. Sect. 19.

Speaking

In geometry, the situation of one thing in regard to another. architecturally, it is the situation of a building in respect of the four cardinal points of the horizon.

POST. (Fr.) An upright piece of timber set in the earth. Any piece of timber whose office is to support or sustain in a vertical direction, as the king and queen posts in a roof, is so called.

POST AND PALING. A close wooden fence constructed with posts fixed in the ground and pales nailed between them. This kind of fence is sometimes called post and railing, though this latter is rather a kind of open wooden fence, used for the protection of young quickset hedges, consisting of posts and rails, &c.

POSTICUM. (Lat.) See CELL.

POSTSCENIUM or PARASCENIUM. (Lat.) In ancient architecture, the back part of the theatre, where the machinery was deposited, and where the actors retired to robe themselves. POSTUMIUS, C. See ARCHITECTS, list of, 37.

POULTRY HOUSE. A building for the shelter and rearing of poultry, whereof, perhaps, the finest example is that at Winnington in Cheshire. The front is one hundred and forty feet in length, with a pavilion at each end, united to the centre by a colonnade of small In the centre cast-iron pillars, supporting a slated roof, which shelters a paved walk.

of the front are four strong columns, and as many pilasters, supporting a slated roof, with an iron gate between them, from which a large semicircular court is entered, with a colonnade round it, and places for the poultry. On one side of the gate is a small parlour, and at the other end of the colonnade a kitchen.

POWER. In mechanics, a force which, applied to a machine, tends to produce motion. If it actually produce it, it is called a moving power, if not, it is called a sustaining power. The term is also used in respect of the six simple machines, viz, the lever, the balance, the screw, the axis in peritrochio, the wedge, and the pulley, which are called the mechanical powers. Pozzo, DEL. See ARCHITECTS, list of, 157. POZZOLANO. See PuzzOLANO.

PRECINCTIO (Lat.) or BALTEUS.

A wide seat, or rather step, round the audience part of

the ancient theatres and amphitheatres. It was termed diagwua by the Greeks. PREACHING CROSS. A cross erected in the highway, at which the monks and others preached to the public.

PRECEPTORY. A manor or estate of the knights templars, on which a church was erected for religious service, and a convenient house for habitation, and generally placed under one of the more eminent members of the fraternity, called the præceptores templi, to have care of the lands and rents of the place. The preceptories were nothing more than cells to the temple, or principal house of the knights in London.

PRESBYTERY. That part of the church reserved for the officiating priests, comprising the choir and other eastern parts of the edifice.

PRESERVING TIMBER. See p. 489.

PRICES OF WORK. See p. 620, et seq.

PRICK POST.

The same as QUEEN POST.

PRIME. (Lat.) A figure in geometry that cannot be divided into any other figures more simple than itself, as a triangle in plane figures, and a pyramid in solids.

A prime number is one that cannot be divided by another number without a remainder. PRIMING. In painter's work, the first colouring of the work, which forms a ground for the succeeding coats.

PRINCIPAL BRACE. One immediately under the principal rafters, or parallel to them, in a state of compression, assisting, with the principals, to support the timbers of the roof. PRINCIPAL POINT. In perspective, a point in the perspective plane upon which a line will fall drawn from the eye perpendicular to that plane. The principal point is, in fact, the intersection of the horizontal and vertical planes, or the point of sight, or of the eye. PRINCIPAL RAFTERS. Those whose sizes are larger than the common rafters, and framed

PRINCIPAL RAY. In perspective, the line passing from the eye to the principal point on the perspective plane.

PRIORY. A building similar in its constitution to a monastery or abbey, the head whereof was called a prior or prioress.

PRISM. (Gг. Пpioμa.) In geometry, an oblong or solid body contained under more than four planes, whose bases are equal, parallel, and similarly situate.

PRISMOID. A solid figure, having for its two ends any dissimilar parallel plane figure of the same number of sides, and all the upright sides of the solid trapezoids. If the ends of the prismoid be bounded by dissimilar curves, it is sometimes called a cylindroid. PRISON. A building erected for the confinement, or safe custody, of those who have transgressed the laws of their country, until, in due course of time, they are discharged. See Book III. Chap. III. Sect. 18.

PRIVATE BUILDINGS. See Book III. Chap. III. Sects. 20, 21, 22.

PROBLEM. (Gr.) In geometry, a proposition in which some operation or construction is required, as to divide a line, to make an angle, to draw a circle through three points not in a right line, &c. A problem consists of three parts: the proposition, which states what is required to be done; the resolution or solution, wherein are rehearsed the step or steps by which it is done; and the demonstration, wherein it is shown that by doing the several things prescribed in the resolution the thing required is obtained.

PRODOMUS. In ancient architecture, the portico before the entrance to the cell of a temple. See CELL.

PRODUCING. In geometry, the continuing a right line to any required length. PROFILE. The vertical section of a body. It is principally used in its architectural sense to signify the contour of architectural members, as of bases, cornices, &c. The profile of an order is in fact the outline of the whole and its parts, the drawing whereof is technically called profiling the order. Profiles of doors are given in Book III. Chap. I. Sect. 19. PROJECTION. The art of representing a body on a plane by drawing straight lines through a given point, or parallel from the contour and from the intermediate lines of the body, if any, so as to cut the plane. When the projection is made by drawing straight lines from a point, it is called a perspective representation; but if formed by parallel lines, it is called an orthographical representation. See PERSPECTIVE, in Book II. Chap. V. Sect. 2., and DESCRIPTIVE GEOMETRY, Book II. Chap. I. Sect. 6. For the method of projecting shadows, see Book II. Chap. IV. Sect. 3.

PROJECTURE. An out-jetting or prominence beyond the naked of a wall, column, &c. By the Greeks projectures were called expoрaι, by the Italians sporti, by the French sailles; so our workmen called them sailings over.

PROLATE. (Lat.) An epithet applied to a spheroid when generated by the revolution of a semi-ellipsis about its longer diameter. PRONAOS. See CELL.

PROPORTION. The just magnitude of each part, and of each part to another, so as to be suitable to the end in view. For the proportions of the several parts of a building, the reader is referred to Book III. Chap. I., wherein they are considered at length. PROPORTIONAL COMPASSES. See COMPASSES.

PROPORTIONS OF ROOMS. See Book III. Chap. I. Sect. 25.

PROPYLEUM. (Gr. Пpo, before, and Пυλŋ, a portal.) Any court or vestibule before a building, or before its principal part; but more particularly the entrance to such court or vestibule.

PROSCENIUM. (Gr.) That part in the ancient theatre whereon the actors performed in front of the scene, being what we call the stage. The Romans called this part the pulpitum.

PROSTYLE. (Gr. Пpo, and Σrvλos, a column.) A portico in which the columns stand in advance of the building to which they belong.

PROTHYRIS. (Gr.) A word used in ancient architecture to signify a cross beam or overthwart rafter, as likewise a quoin or course of a wall. See CONSOLE.

PROTHYRUM. (Gr.) A porch at the outer door of a house; a portal.

PROTRACTOR. (Lat. Protractus.) An instrument for laying down an angle in drawing or plotting.

PSEUDISO DOMUM.

See ISODOMUM.

PSEUDODIPTERAL or FALSE DIPTERAL. A disposition in the temples of antiquity wherein there were eight columns in front and only one range round the cell. It is called false or imperfect, because the cell only occupying the width of four columns, the sides from the columns to the walls of the cell have no columns therein, though the front and rear present a column in the middle of the void. See TEMPLE.

PSEUDOPERIPTERAL OF IMPERFECT PERIPTERAL. A disposition in the ancient temples, in which the columns on the sides were engaged in the wall, and wherein there was no portico except to the façade in front; such are the Maison Carrée at Nismes, and the temple of Fortuna Virilis at Rome.

PTERA. See AISLES.

PTEROMA. (Gr. ПITеpov, a wing.) The space between the wall of the cell of a temple and the columns of the peristyle, called also ambulatio.

PUDDLING. The filling behind a wall, filling up a cavity, or banking up with clay tempered with water, and carefully rammed down with the repeated strokes of beaters or beetles.

PUGGING. A coarse kind of mortar laid upon the sound boarding between joists, to prevent the transmission of sound from the apartment above to that below. PUG-PILING. The same as dovetailed piling, or pile planking.

PULLEY. (Fr.) One of the five mechanical powers, consisting of a wheel or rundle, having a channel around it and turning on an axis, serving, by means of a rope which slides in its channel, for the raising of weights. See p. 391.

PULLEY MORTISE. The same as CHASE MORTISE, which see.

PULPIT. (Ital. Pulpito.) An elevated place, an enclosed stage or platform for a preacher in a church. The ancient ambo served the same purpose. The pulpits of the present day are generally wretched affairs, and have great affinity in form to sugar hogsheads or rum puncheons with the heads knocked out. The Catholic churches abroad almost invariably furnish fine specimens of carving and composition in their pulpits. PULPITUM. (Lat.) See PROSCENIUM.

PULVINARIA. (Lat.) Cushions in the ancient temples whereon the statues of the gods were sometimes laid.

PULVINATED. See FRIEZE.

РСМР. See p. 584, 585., where the different pumps for buildings are described. PUNCHION. (Fr. Poinçon.) A name common to iron instruments used in different trades for cutting, inciding, or piercing a body. In carpentry it is a piece of timber placed upright between two posts whose bearing is too great, serving, together with them, to sustain some heavy weight. The term is also applied to a piece of timber raised upright under the ridge of a building, and in which are jointed the small timbers.

Also

to the arbor or principal part of a machine on which it turns vertically, as that of a

crane.

PURBECK STONE. A species of stone obtained from the island of Purbeck in Dorsetshire, of a very hard texture.

PURFLED. (Fr. Pourfiler.) Ornamented work in stone, or other material, representing embroidery, drapery, or lace work.

PURLINS. Horizontal pieces of timber lying generally on the principal rafters of a roof to lessen the bearings of the common rafters.

PUTEAL.

The marginal stone of a well. The celebrated one of Scribonius Libo was erected by order of the senate to mark the spot where a thunderbolt had fallen near the statues of Marsyas and Janus by the Comitia.

PUTLOGS. See LEDGERS,

PUTTY. A sort of paste consisting of whiting, with or without a small portion of white lead, and linseed oil, beaten together until it assumes a kind of tough consistency like dough. In this state it is used by glaziers for fixing in the squares of glass to sash windows, &c., and also by house-painters to stop up holes and cavities in woodwork before painting. PUZZOLANA. A grey-coloured earth deriving its name from Puzzuoli, whence it was originally brought. It is a volcanic matter found in many other parts of Italy, and generally in the neighbourhood of volcanoes active or extinct, from which it has been thrown out in the form of ashes. It immediately hardens when mixed with one-third of its weight of lime and water, forming an admirable water cement. See Book II. Chap. II. Sect. 10.

PYCNOSTYLE. (Gr. Пuкvos, close, and ΣTuλos, column.) See COLONNADE. PYRAMID. (Gr. Пup, fire.) A solid standing on a square, triangular, or polygonal basis, and terminating at top in a point; or a body whose base is a regular rectilinear figure and whose sides are plain triangles, their several verticals meeting together in one point. It is defined by Euclid as a solid figure consisting of several triangles whose bases are all in the same plane and have one common vertex. When the base of a pyramid is but small in proportion to its height, it is called an obelisk. See that word. For some account of the pyramids of Egypt see Book I. Chap. II. Sect 7.

The principal properties of pyramids are as follow: 1. All pyramids and cones standing on the same base and having the same altitude are equal. 2. A triangular pyramid is the third part of a prism, standing on the same base and of the same altitude. 3. Hence, since every multangular may be divided into triangulars, every pyramid is the third part of a prism standing on the same base and of the same altitude. 4. If a pyra mid be cut by a plane parallel to its base, the sections will be similar to the base. 5. All pyramids, prisms, cylinders, &c., are in a ratio compounded of their bases and altitudes; the bases therefore being equal they are in proportion to their altitudes, and the altitudes being equal, they are in proportion to their bases. 6. Similar pyramids, prisms, cylinders, cones, &c., are in a triplicate ratio of their homologous sides. 7.

Equal pyramids, &c., reciprocate their bases and altitudes, i. e. the altitude of one is to that of the other, as the base of the one is to the base of the other. 8. A sphere is equal to a pyramid whose base is equal to the surface, and its height to the radius of the sphere.

PYRAMID, FRUSTUM OF A. See FRUSTUM.

PYRAMIDION.

The small flat pyramid which terminates the top of an obelisk. PYTHEUS. See ARCHITECTS, list of, 8.

Q.

QUADRA. (Ital.) A square border of frame round a basso-relievo, panel, &c. ; the term is not strictly applicable to any circular border. The term is also applied to the bands or fillets of the Ionic base on each side of the scotia; and also to the plinth or lower member of the podium.

QUADRANGLE. Any figure with four angles and four sides. This term is in architecture in England applied to the inner square or rectangular court of a building, as in the college courts of Oxford, &c.

QUADRANT. (Lat.) The quarter of a circle, or an arc of it containing ninety degrees within its enclosed angle.

QUADRATURE. (Lat.) The determination of the area of a figure in a square, or even any

other rectilinear form.

QUADRELS. Artificial stones perfectly square, whence their name, much used formerly by the Italian architects. They were made of a chalky or whitish and pliable earth, and dried in the shade for at least two years.

QUADRIFORES. (Lat.) In ancient architecture folding doors whose height was divided into two parts. When they opened in one height, they were termed fores valvate or

valva.

QUADRILATERAL.

In geometry a figure whose perimeter consists of four right lines making four angles, whence it is also called a quadrangular figure. QUARREL, vulgarly called QUARRY. (Fr. Carré.) A square or lozenge-shaped piece of glass used in lead casements.

QUARRY. (Irish, Carrig.) A place whence stones or slates are procured. The principal stone quarries of England have been given in the body of the work, Book II. Chap. II. Sect. 1. to which place the reader is referred. The slates obtained from the different quarries of the country may be found from the information in Book II. Chap. II.

Sect. 8.

QUARRYING. The operation of extracting the produce of a quarry is one which requires much practical knowledge to render it beneficial to the owner of a quarry, but in respect of the particulars whereof this work does not require our notice.

QUARTER PARTITION. One consisting of quarters.

QUARTER ROUND. The same as OvOLO and ECHINUS, which see, being a moulding whose profile is the quadrant of a circle.

QUARTERING. A series of quarters, as in a partition, &c.

QUARTERFOIL. (Fr. Quatrefeuille.) A modern term denoting a form disposed in four segments of circles, and so called from its imagined resemblance to an expanded flower of four petals. It is only found in the windows, pannels, &c., of Gothic architecture. Mr. Gunn with charming simplicity, not unusual among the amateur writers on Gothic architecture, thinks that the form has no reference to any type in the vegetable kingdom, but that it was originally a representation of the Greek cross rounded towards the extremities. If the writings on the subject from the two universities of the country were all put in juxtaposition, they would perhaps afford more scope for mirth than was ever exhibited on any subject.

QUARTERS. Small vertical timber posts, rarely exceeding four by three inches, used instead of walls for the separation or boundary of apartments. They are placed, or ought to be, about twelve inches apart, and are usually lathed and plastered in the internal apartments, but if used for external purposes are commonly boarded.

QUARTZ. (Germ.) A mineral production better known by the name of rock crystal. It includes a variety of stones with which we have nothing here to do, and the only motive for mentioning it is its occurrence in the granites, wherein it is immediately recognised, from its glass-like appearance.

QUAY. (Fr.) A bank formed towards the sea or on the side of a river for free passage, or for the purpose of unloading merchandise.

QUEEN-POST. A suspending post where there are two in a trussed roof.
QUICKLIME. See Book II. Chap. II. Sect 10.

QUIRK.

A piece taken out of any regular ground-plot or floor; thus, if the ground