second to triangles formed upon the surface of a sphere by three circular arcs.

This

latter is of less importance to the architect than the former, which is, for his purpose, sufficiently explained in Book II. Chap. I. Sect. 14.

TRILATERAL. (Lat.) Having three sides.

TRIM. (Verb.) To fit to any thing; thus, to trim up, is to fit up.

TRIMMED. A piece of workmanship fitted between others previously executed, which is then said to be trimmed in between them. Thus, a partition wall is said to be trimmed up between the floor and the ceiling; a post between two beams; a trimmer between two joists. TRIMMED OUT. A term applied to the trimmers of stairs when brought forward to receive the rough strings. TRIMMER. A small beam, into which are framed the ends of several joists. The two joists, into which each end of the trimmer is framed, are called trimming joists. arrangement takes place where a well-hole is to be left for stairs, or to avoid bringing joists near chimneys, &c.

This

TRINE DIMENSIONS. Those of a solid, including length, breadth, and thickness; the same as threefold dimensions.

TRIPOD. (Gr. Tpeis, and Пovs, a foot.)

A table or seat with three legs. In architectural ornament its forms are extremely varied, many of those of the ancients are remarkable for their elegance and beauty of form.

TRISECTION. The division of any thing into three equal parts.

TROCHILUS. (Gr. Tpoxiλos, a pulley.) An annular moulding whose section is concave, like the edge of a pulley. It is more commonly called a scotia, and its place is between the two tori of the base of a column.

TROCHOID. (Gr. Tpoxos a wheel, and Eidos, shape.) A figure described by rolling a circle upon a straight line, such circle having a pin or fixed point in its circumference upon a fixed plane, in or parallel to the plane of the moving circle. It is also called a cycloid.

TROPHONIUS. See ARCHITECTS, list of, 3.

TROPHY. (Gr. Трonaιov.) An ornament representing the trunk of a tree charged with various spoils of war.

TROUGH. (Sax. Tnob.) A vessel in the form of a rectangular prism, open on the top for holding water.

TROUGH GUTTER. A gutter in the form of a trough, placed below the dripping eaves of a house, in order to convey the water from the roof to the vertical trunk or pipe by which it is to be discharged. It is only used in common buildings and outhouses.

TRUNCATED. (Lat. Trunco, I cut short.) A term employed to signify that the upper portion of some solid, as a cone, pyramid, sphere, &c. has been cut off. The part which remains is called a frustum.

TRUNK. That part of a pilaster which is contained between the base and the capital; also a vessel open at each end for the discharge of water, rain, &c.

TRUSS. (Fr. Trousse.) A combination of timber framing, so arranged, that if suspended at two given points, and charged with one or more weights in certain others, no timber would press transversely upon another except by timbers exerting equal and opposite forces. The principle of a truss is explained at p.546.

TRUSS PARTITION. One containing a truss within it, generally consisting of a quadrangu lar frame, two braces, and two queen posts, with a straining post between them, opposite to the top of the braces.

TRUSSED BEAM. One in which the combination of a truss is inserted between and let into the two pieces whereof it is composed.

TRUSSING PIECES. Those timbers in a roof that are in a state of compression.

TRY. (Verb.) To plane a piece of stuff by the rule and square only.

TUBE, (Lat.) A substance perforated longitudinally; generally quite through its length.

TUMBLED IN. The same as trimmed in. See TRIMMED.

TUNNEL. (Fr.) hill, &c. TURNING PIECE. A board with a circular edge for turning a thin brick arch upon. TURPENTINE. A resinous juice extracted from several trees belonging to the genus Pinus. All turpentine is obtained by exudation and hardening of the juice flowing from incisions into the pine trees. To obtain the oil of turpentine, the juice is distilled in an ap. paratus like the common still, and water is introduced with the turpentine. TURRET. (Lat. Turris.) A small tower often crowning the angle of a wall, &c. TUSCAN ORDER. See Book III. Chap. I. Sect. 3.

A subterranean channel for carrying a stream of water under a road,

TUSK. A bevel shoulder made above a tenon, and let into a girder to give strength to the

tenon.

TYMPANUM. (Gr.) The naked face of a pediment (see PEDIMENT) included between the

level and raking mouldings. The word also signifies the die of a pedestal, and the panel of a door. TYPE. (Gr. TUTOS.) A word expressing by general acceptation, and consequently applicable to, many of the varieties involved in the terms model, matrix, impression, &c. It is, in architecture, that primitive model, whatever it may have been, that has been the foundation of every style, and which has guided, or is supposed to have guided, the forms and details of each. What it was in each style is still only conjecture, and forms the ground for the various observations on them in various parts of the body of this work. TYPE.

The canopy over a pulpit.

U.

UNDERPINNING. Bringing a wall up to the ground sill.

The term is also used to denote the temporary support of a wall, whose lower part or foundations are defective, and the bringing up new solid work whereon it is in future to rest.

UNGULA. The portion of a cylinder or cone comprised by part of the curved surface, the segment of a circle, which is part of the base, and another plane.

UNIVERSITY. An assemblage of colleges under the supervision of a senate, &c. See Book III. Chap. III. Sect. 8.

UPHERS. Fir poles, from four to seven inches in diameter, and from twenty to forty feet in length. They are often hewn on the sides, but not entirely to reduce them square. They are chiefly used for scaffolding and ladders, and are also employed in slight and common roofs, for which they are split.

UPRIGHT. The elevation of a building; a term rarely used.

URN. (Lat.) A vase of a circular form, destined among the ancients to receive and preserve the ashes of the dead.

USTAMBER. See ARCHITECTS, list of, 80.

V.

VAGINA. (Lat.) The lower part of a terminus in which the statue is apparently inserted. VALDEVIRA. See ARCHITECTS, list of, 224.

VALERIUS OF OSTIA. See ARCHITECTS, list of, 32.

VALLEY. (Lat.) The internal meeting of the two inclined sides of a roof. The rafter which supports the valley is called the valley rafter or valley piece, and the board fixed upon it for the leaden gutter to rest upon is called the valley board. The old writers called the valley rafters sleepers.

VALUATIONS OF PROPERTY. See APPENDIX, p. 882.

VALVED. Any thing which opens on hinges.
VANBRUGH. See ARCHITECTS, list of, 270.

VANE. A plate of metal shaped like a banner fixed on the summit of a tower or steeple, to show the direction of the wind.

VANISHING LINE. In perspective, the intersection of the parallel of any original plane and the picture is called the vanishing line of such plane. The vanishing point is that to which all parallel lines in the same plane tend in the representation. VANVITELLI. See ARCHITECTS, list of, 291.

VARIATION OF CURVATURE. The change in a curve by which it becomes quicker or flatter in its different parts. Thus, the curvature of the quarter of an ellipsis terminated by the two axes is continually quicker from the extremity of the greater axis to that of the lesser. There is no variation of curvature in the circle. VARNISH. A glossy coat on painting or the surface of any matter. It consists of different resins in a state of solution, whereof the most common are mastic, sandarac, lac, benzoin, copal, amber, and asphaltum. The menstrua are either expressed, or essential oils, or alcohol.

VASE. (Lat. Vas.) A term applied to a vessel of various forms, and chiefly used as an ornament. It is also used to denote the bell, or naked form, to which the foliage and volutes of the Corinthian and Composite capitals are applied. The vases of a theatre in ancient architecture were bell-shaped vessels placed under the seats to produce reverberation of the sound.

VAULT. (It. Volto.) An arched roof over an apartment, concave towards the void, whose section may be that of any curve in the same direction. Thus a cylindric vault has its surface part of a cylinder. A full-centred vault is formed by a semi-cylinder. When a vault is greater in height than half its span, it is said to be surmounted when less surbased. A rampant vault springs from planes not parallel to the horizon. The double vault occurs in the case of one being above another. A conic vault is formed of part of the surface

of a cone, as a spherical vault consists of part of the surface of a sphere. The plane of an annular vault is contained between two concentric circles. A vault is said to be simple when formed by the surface of some regular solid round one axis, and compound when formed of more than one surface of the same solid or of two different solids. A cylindrocylindric vault is formed of the surfaces of two unequal cylinders: and a groined vault is a compound one rising to the same height in its surfaces as that of two equal cylinders, or a cylinder with a cylindroid. The reins of a vault are the sides or walls that sustain the arch. See the section on ARCHES, Book II. Chap. I. Sect. 9. VELARIUM. (Lat.) The great awning which by means of tackle was hoisted over the theatre and amphitheatre to protect the spectators from the rain or the sun's rays. VELLAR CUPOLA. A term used by Alberti to denote a dome or spherical surface terminated by four or more walls, frequently used over large staircases and salons, and other lofty apartments.

VENEER. A very thin leaf of wood of a superior quality for covering doors or articles of furniture which are made of an inferior wood.

VENETIAN DOOR, A door having side lights on each side for lighting an entrance hall. VENETIAN WINDOW. One formed with three apertures separated by slender piers from each other, whereof the centre one is much larger than those on the sides.

VENT. The flue or funnel of a chimney; also any conduit for carrying off that which is offensive.

VENTIDUCT. A passage or pipe for the introduction of fresh air to an apartment. VENTILATION. The continual supply of fresh air to an apartment, a subject which latterly has been considered so necessary, though much neglected as the moderns seem to think by their ancestors, that a volume would not hold the schemes that have been latterly proposed for that purpose. Generally it is enough for the architect to provide means for letting off the hot air of an apartment or building by apertures at the upper part of the rooms, &c., to which the hot air will ascend without afflicting with the currents of fresh air that are to be introduced those that inhabit them.

VERMICULATED. (Lat.) A term applied to rustic-work which is so wrought as to have the appearance of having been eaten into by worms.

VERTEX. (Lat. the top.) A term generally applied to the termination of any thing finishing in a point, thus we say the vertex of a cone, &c.

VERTICAL ANGLES. The opposite ones made by two straight lines cutting each other. VERTICAL PLANE. One whose surface is perpendicular to the horizon.

VESTIBULE. (Lat. Vestibulum.) An apartment which serves as the medium of communication to another room or series of rooms. In the Roman houses it appears to have been the place before the entrance where the clients of the master of the house, or those wishing to pay their court to him, waited before introduction. It was not considered as forming a part of the house. The entrance from the vestibulum led immediately into the atrium, or into the cavædium.

VESTRY. (Lat. Vestiarium.) An apartment in, or attached to, a church for the preservation of the sacred vestments and utensils.

VICE. A term in old records applied to a spiral or winding staircase. In mechanics a machine serving to hold fast any thing worked upon, whether the purpose be filing, bending, riveting, &c.

VILLA. A country-house for the residence of an opulent person. Among the Romans there were three descriptions of villa, each having its particular destination, namely. The Villa urbana, which was the residence of the proprietor, and contained all the conveniences of a mansion in the city. The Villa rustica, which contained not only all that was essential to rural economy, such as barns, stables, &c., but comprised lodging apartments for all those who ministered in the operations of the farming establishment. The Villa fructuaria was appropriated to the preservation of the different productions of the estate, and contained the granaries, magazines for the oil, cellars for the wine, &c. See Book III. Chap. III. Sect. 22.

VINCI, DA. See ARCHITECTS, list of, 181.

VINERY. A house for the cultivation of vines. See CONSERVATORY.

VISORIUM. (Lat.) See AMPHITHEATRE.

VISUAL POINT. In perspective a point in the horizontal line in which the visual rays unite.

VISUAL RAY. A line of light supposed to come from a point of the object to the eye.
VITONI. See ARCHITECTS, list of, 168.

VITRIFICATION. The hardening of argillaceous stones by heat.

VITRUVIUS POLLIO.

VITRUVIUS CERDO.

See ARCHITECTS, list of, 40.

See ARCHITECTS, list of, 41.

Vivo. (Ital.) The shaft of a column.

VOLUTE. A spiral scroll which forms the principal feature of the Ionic and Composite capitals.

VOMITORIA. (Lat.) See AMPHITHEATRE.

VOUSSOIR. (Fr.) A wedge-like stone or other matter forming one of the pieces of an arch. See ARCH.

W.

WAGON-HEADED CEILING. The same as cylindric ceiling. See VAULT.

WAINSCOT. (Dutch, Wayschot.) A term usually applied to the wooden lining of walls in panels. The wood originally used for this purpose was a foreign oak (see p. 482.); hence the name of the material became attached to the work itself. WALKELYN. See ARCHITECTS, list of, 84.

WALL. A body of materials for the enclosure of a building and the support of its various parts. See Book II. Chap. I. Sect. 10.

WALLS OF THE ANCIENTS.

Emplecton, Isodomum, Pseudo-isodomum. See MASONRY. WALLS, CASED. Those faced up anew round a building, in order to cover an inferior material, or old work gone to decay.

WALNUT. A forest tree useful for building purposes. See p. 484.

WALSINGHAM. See ARCHITECTS, list of, 142.

WARE. See ARCHITECTS, list of, 289.

WARREN. See ARCHITECTs, list of, 250,

WATER-CLOSET. See p. 583.

WATER SHOOT. See SQUARE SHOOT.

WATER TABLE. See TABLE, WATER.

WAYNEFLETE. See ARCHITECTS, list of, 165.

WEATHER-BOARDING.

See BOARDING for outside Work.

WEATHER-TILING. The covering an upright wall with tiles.

WEDGE. (Dan. Wegge.) An instrument used for splitting wood or other substances; it is usually classed among the mechanical powers. See p. 392.

WEIGHT. (Sax. Wiht.) In mechanics, a quantity determined by the balance; a mass by which other bodies are examined. It denotes anything to be raised, sustained, or moved by a machine as distinguished from the power, or that by which the machine is put in motion.

WEIGHT, in commerce, denotes a body of given dimensions, used as a standard of comparison for all others. By an act of parliament passed in June 1824, all weights were to remain as they then were, that act only declaring that the imperial standard pound troy shall be the unit or only standard measure of weight from which all other weights shall be derived and computed; that this troy pound is equal to the weight of 22-815 cubic inches of distilled water weighed in air at the temperature of 62° of Fahrenheit's thermometer, the barometer being at 30 inches, and that there being 5760 grains in a troy pound, there will be 7000 such grains in a pound avoirdupois.

The avoirdupois pound: pound troy :: 175: 144, or ::11: 9 nearly; and an avoirdupois pound is equal to 1 lb. 2 oz. 11 dwts. 16 grains troy. A troy ounce =1 oz. 1.55 dr. avoirdupois.

The following is a table of weights according to the new French system.

2-6803 lbs. troy. 12-5055 lbs. avoirdupois. 3.2 ounces troy. 3.52 ounces avoirdupois. 6.43 dwts. troy. 15:438 grains troy. 0.643 pennyweight. 0.032 ounce troy.

{

The following table exhibits the proportion of weights in the principal places of Europe to 100 lbs. English avoirdupois.

91 lbs. 8 oz. for the pound of Amsterdam, Paris (old), &c.

100 lbs. English

=

Antwerp or Brabant.

Rouen (the Viscounty weight).
Lyons (the city weight).

Rochelle.

Toulouse and Upper Languedoc.
Marseilles or Provence.

Geneva,

Hamburgh.

Frankfort, &c.

Leipsic, &c.
Genoa.
Leghorn,
Milan,

Venice.
Naples.

Seville, Cadiz, &c.
Portugal.

Liege.

Russia.

Sweden.
Denmark.

The Paris pound (poids de marc of Charlemagne) contained 9216 Paris grains; it was divided into 16 ounces, each ounce into 8 gros, and each gros into 72 grains. It is equal to 7561 English troy grains.

The English troy pound of 12 ounces contains 5760 troy grains = 7021 Paris grains. The English avoirdupois pound of 16 ounces contains 7000 English troy grains, and is equal to 8538 Paris grains.

To reduce Paris grains to English troy grains, divide by

Or, to reduce English troy grains to Paris grains, multiply by
To reduce Paris ounces to English troy, divide by
To reduce English troy ounces to Paris, multiply by

1-2189.

10

1-015734.

WEIGHTS OF A SASH are two weights by which the sash is suspended and kept in the situation to which it is raised by means of cords passing over pulleys. The vertical sides of the sash frames are generally made hollow in order to receive the weights, which, by this means are entirely concealed. Thus, to keep the sash in suspension, each weight must be half the weight of the sash. The cords should be of good quality, or they soon fret to pieces.

WELCH GROINS. A groin formed by the intersection of two cylindrical vaults, one whereof is of less height than the other.

WELL. A deep circular pit, or sort of shaft, sunk by digging down through the different strata or beds of earthy or other materials of the soil, so as to form an excavation for the purpose of containing the water of some spring or internal reservoir, by which it may be supplied.

WELL-HOLE. In a flight of stairs, the space left in the middle beyond the ends of the steps. WESTON. See ARCHITECTS, list of, 137.

WHEEL. (Sax.) In mechanics, an engine consisting of a circular body turning on an axis, for enabling a given power to move or overcome a given weight or resistance. This machine may be referred to the lever.

WHEEL WINDOW. In Gothic architecture, a circular window, with radiating mullions, resembling the disposition of the spokes of a wheel.

WHETSTONE. A stone of fine quality by which tools for cutting wood are brought to a fine edge, after being ground upon a gritstone, or grinding-stone, to a rough edge. WHITE LEAD. A material forming the basis of most colours in house-painting. The common method of making it is by rolling up thin leaden plates spirally, so as to leave the space of about an inch between each coil. These are placed vertically in earthen pots, at the bottom of which is some good vinegar. The pots are covered, and exposed for a length of time to a gentle heat in a sandbath, or by bedding them in dung. The vapour of the vinegar, assisted by the tendency of lead to combine with the oxygen which is present, corrodes the lead, and converts the external portion into a white substance which comes off in flakes. These are washed and dried in stoves in lumps, and form the white lead of the painters.

WICKET. A small door made in a gate.