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seldom omitted; When the tracery is of a complicated cha-racter, we find a sort of subordination observed amongst theless significant members ; thus, the principal compartmentsof a window are divided by large bars, consisting of a largeassemblage of mouldings, of which only a portion are em-ployed in the bars which form the sub-divisions.
The Gothic buildings of France are noted for a peculiarform of tracery, termed flamboyant, from its flame-likeappearance. It is similar to some examples of our flowing-tracery, but differs in this, that the leaf-like openings alwaysterminate in a sharp point at the top, and thus assume ratherthe appearance of flames.
Tracery is employed, not only in windows, but also inscreens, panels, &c., even when not pierced.
TRAIL, a running, or continuous, enrichment of leavesor flowers, with their tendrils or stalks, &c. Such enrich-ment is common in Gothic mouldings.
TRAMMEL, a rod of wood or metal, having slidingpieces, to which are affixed points, with which to describelarge circles, or set off long distances.
TRANSEPT, that portion of a cruciform church whichextends across the main body of the building, and usuallyseparates the nave and choir. Thus, the nave and choirrunning from west to east, the transept will have its directionfrom north to south, and in the plan forms the shorter armsof the cross, projecting more or less beyond the nave andchancel aisles. Sometimes double transepts occur east andwest of each other, as at Canterbury and Lincoln cathedrals ;occasionally we find one at the extreme west, as at Ely; andalso at extreme east, as at Durham and Peterborough. SeeCatherdal, Church .
TRANSITION, a term applied to certain classes ofarchitectural examples, which appear to form a connectinglink between two well-defined styles. It is especially appliedto those buildings which are intermediate between the Nor-man, or Romanesque, and the Pointed styles. See GothicArchitecture.
TRANSOM, (from the Latin transenna, a cross beam,) injoinery, a horizontal piece, framed across a double-lightedwindow. When a window has no transom, it is called aclear story window.
Transom, a horizontal mullion, dividing a window into twostages in height. Transoms were not generally in use pre-vious to the Perpendicular period of Gothic architecture,but are occasionally found in spire-lights of both Early Eng-lish and Decorated buildings, where they seem to have beenrequisite for the purpose of strengthening the window.They are also very common in domestic buildings of allperiods, and in those of later date almost universal, the lightsbeneath being usually arched and cusped.
TRANSTRA, the horizontal timbers in the roof of Romanbuildings.
TRANSVERSE, (from the Latin trans , over, and vertoversus, to turn,) lying in a cross direction.
Transverse Strain, the strain against a piece of timberside-ways, by which it is more easily bent, or broken, thanwhen compressed, as a straining-piece, or drawn in a direc-tion of its length, as a tie.
TRANSYTE, a narrow or triforial passage.
TRAPEZIUM, (from rpaviiwv,) a plane figure with fourunequal sides and angles. As every rectilinear figure maybe divided into as many triangles, wanting two, as the figurehas sides; a trapezium, which is a right-lined figure of foursides, may be divided into two triangles by a diagonal.Therefore, to find the superficial content, find the area ofeach triangle, and the sum of these areas is that of thetrapezium.
TRAVELLING - CRANE, a very useful machin ® si stshoisting materials in the erection of a building. I 1 c0 ., g t0of a crab fixed on a carriage, which is movable upon rany part of a building where it may be required. hoardTRAVERSE, (from the Latin traversus,) to plane a .^ tgnin a direction transverse to the fibres, in order to strai 0it in that direction. _ . ^
Traverse, a gallery or loft of communication, suthose found in large churches. . n ( 8 l
TREAD OF THE STEP OF A STAIR, the horizonpart of the step.
TREBEATION, the same as Entablature . _ hitec-TREFOIL, an ornament much used in Gothic ar ? t j 1 j I1 ature, consisting of a figure of three cusps disposed wl ^ee-circle, and enclosing a space similar in form to the ^. g ,leaved clover. Trefoils, however, are not invariab yposed within a circle ; any cusped figure which enctri-lobed space is termed a trefoil, even if it * iavetwo cusps. f t j,in
TRELLIS WORK, a reticulated framing, made .° u j ate dbars of wood, used in rural architecture. Any retiework.
TRESSEL, or Trussel. See Trussel. a
TRIANGLE, (from the Latin ires, three, and an ^ nt jy 8 9corner,) a plane figure of three sides, and conseque imany angles. In measuring, all rectilinear figures m a jjreduced to triangles ; and in constructions for car P e ” aI) gleS>frames of more than three sides must be reduced to trito prevent a revolution round the angles. j, a ve
TRIANGULAR COMPASSES, such compasses asthree legs, or feet, by which any triangle, or three Fmay be taken off at once. See Instruments. -guts-
TRICLINIUM, a hall, or apartment, used by the antSee Cyzicene. hptvf een
TRIFORIUM, the gallery contained in the spare ^ gen t-the vault and timber-roof of the aisles of a church ; P gt>v eering towards the interior a continuous arcade, situatethe lower arcade and the clere-story. r hafi ne ^’
TRIGLYPHS, (from rpeis, three, and y\v<pag, a ^ fe( j onor furrow,') the tablets in the Doric frieze, chain jh®the two vertical edges, and with two channe p 0 ric,middle called glyphs, or carvings. In the Gr ec ' a jj 0 u)an>the triglyph is placed upon the angle; but in • th ethe triglyph next the angle is over the cen tcolumn. a cor» eT >
TRIGONOMETRY, (from rp f 7 c , three, 7° yl } a ’ “ t) kno" r °and /Jtrpeto, to measure) the art of measuring 111 - ve n- ,parts of a triangle, from the remaining parts pi a jie tr> 'Trigonometry is either Plane, or Spherical. {g of®gonometry is the art of measuring the unknown Fplane rectilinear triangle. This, on many °® caS \ a sc® r ^be of considerable use to the architect and eng>n® el .^| i( .taining certain distances and dimensions, which me f 0 uwise be very inconvenient to obtain. Indeed, i il( j er sto°®upon such obvious principles, that when once ucan never be forgotten. _ - sl
Every triangle consists of six parts, viz.and the three angles : any three of these six p ar s .’ ne( j.three angles, being given, the rest may be ascei
Definitions. >htl> ne ’
Definition 1.—The chord of an arc is a stra'ojoining its two extremities.
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Definition 2. —The sine of an arc is » —■drawn from one extremity perpendicular to * 1drawn through the other extremity of the arc,Corollary. —Hence, the sine of an arc is 8
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