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is very quickly formed (as before described^ without anycentering.
The material fittest for this land of building are thevarious kinds of sand-stone, including the calcareous sand-stone of Cutch. The laterite, or iron-clay, although a goodmaterial, and the only one hitherto used, is apparently not soproper as the substance generally called free-stone, which isworked with saws, &c., and would be found to answer betterthan the laterite, which can be shaped only with a pickaxe,and is very heavy.
This iron-clay is found to extend from Bancoate, e. n. e.,to, I believe, Ceylon, lying over the trap-rock, even on thehighest Ghauts, but is very unequal in thickness and quality ;that of Purnalla and Pawnghur, for instance, being of thesoftest and most porous kind, and that near Mahabulesher ofthe best. This stone, when exposed to rain, &c, becomesvery •hard, if good; but if taken from any depth, is so soft asto be easily cut with a knife. It is hence called soap-stoneat Belgaum and other Madras stations.
If adopted in Europe , buildings of this kind would be asremarkable for warmth as in this country for coolness. Butthe plastering outside would not be advisable on account ofthe frost; tiles, however, or slate, would protect the roofcompletely.
The principal advantages of these buildings in this coun-try are, their coolness, and the little expense incurred inannual and special repairs ; indeed, the latter will never berequired, if the buildings be properly constructed at first.It is also very evident, that they can never take fire, nor canwhite ants affect them ; of course they could be built ofseveral stories, the form of the fioor-ribs being merely asmall segment of a circle (or ellipse) instead of a com-pound of two, as in the roof. The upper floor of thejailor’s house at Rutnaghery is thus built, as also part ofanother house.
Vault, Reins of a, the sides or walls which sustain thearch.
VAULTING- SHAFT, the shaft which supports the ribsof a groined vault. These shafts either rise direct from theground, or are supported upon corbels at a height abovethe ground ; they are frequent in Romanesque and Gothicbuildings.
VELLAR CUPOLA, a dome, or spherical surface, ter-minated by four or more walls. This kind of ceiling is fre-quently used over great staircases, as also over saloons, orother lofty apartments. The term is used by Alberti, vol. i.book iii., chap. 14, in the sense here defined.
VENEER, a very thin leaf of wood, of a superior qua-lity, for covering doors, or articles of furniture, made of aninferior wood.
VENETIAN DOOR, a door lighted on each side.
Venetian Window, a window in three separate apertures,divided by slender piers, and having the centre aperturelarger than the side ones. See Adams’s Ruins of Spolatro,p. 26 ; likewise Disgodily’s Roman Antiquities, vol. ii. Bathsof Diocletian .
VENT, (from the French , fente, a small aperture,) thetube of a chimney, for conveying the smoke from the fire.The term is mostly used in Scotland. In London it is calledflue, and in many parts of England funnel.
VENTIDUCTS, (from the Latin , ventus, wind, and duc-tus, a passage,) subterraneous places where fresh or cool airis kept, being received by proper funnels and valves.
VENTILATION, the method of supplying buildings withfresh air. In buildings which are intended for habitation,or where large bodies of persons are at any time to be con-gregated, it is requisite that there should be some means of
replenishing the apartment with a constant supply of P urair. This necessity arises from the fact, that air, when cmpassed through the human system, is unfit for re-insp' ratl ° ’that portion which is emitted being not only useless, ’deleterious to health. On this account it becomes necessa'fto remove this vitiated air, and to substitute fresh air, wshould be at a temperature of about 60° to 65°. The VI ' eated air, on being emitted from the mouth, has a tempei'a 11 ’ 1 ^between 80° and 90°, and being thereby rarifled and rendei®^lighter, has a tendency to rise to the upper part of the ap 8 ' |ment. The method hereby naturally suggested for its renioy^is the provision of some means of escape at the top of ^apartment; the success of this method, however, wouldnullified, if the heated air, on emerging from the top °f ^room into a shaft intended to conduct it away, were to ®with a current of cold air, and it is therefore found necess® 'to heat the air in the shaft, so as to assist the upward dj 8 ^It is further necessary to keep up a constant supply of *J e .air to take the place of the foul air as it is removed ; thisnecessary, not only for the purposes of health, but alsopreserve the upward draft. In some instances, means >'< _been adopted of forcing fresh air in with fans or beH° ’but this is scarcely necessary, for if the fresh air be 0allowed admission into the apartment, it will naturallyto fill up the vacuum caused by the dispersion of the fou ^These methods, however, are seldom adopted together; sotimes the shaft, and at others the fan, is employed, y 5 j igpersons contend, that the method of heating the air in uge3shaft does not answer the intended object, but rather ca ■a downward current. In supplying fresh air, it i s t0 . t - 3observed, that cold currents of air are to be avoided . 1 ^
sometimes customary to heat the air to a certain temp eia . „before admitting it into the apartment, the temperature °regulated according to the season of the year. , a
VENTILATOR, (from the Latin , ventilo, to fan ’{ hemachine made to turn with the wind, and placed > n ^wall or roof, in order to throw a due quantity of R einto a close apartment. . ve ,
VERGE, a small ornamental shaft in Gothic architecVerge Board, same as Barge Board. ea r
VERMICULATED RUSTICS, stones worked to appas if eaten by worms. • itef'
VERSED SINE, that part of the radius of a circl f e ^ nC e,cepted between the foot of the sine and the circulateotherwise termed sagitta. See Trigonometry. . tei"
VERTEX, (Latin, ) the top, generally applied to * i ^ #mination of anything ending in a point; as the veite xpyramid, &c. _ /• the
Vertex of a Conic Section, the extremity 0abscissa. , v two
VERTICAL ANGLES, the opposite angles made oystraight lines cutting each other. , j c jj its
Vertical Plane, that position of a plane in 1surface is perpendicular to the horizon. , Hec°'
VESICA-PISCIS, a figure frequently used in the
rative part of Early English and Gothic architect® ^rally. It is formed by the intersection of two arcs ^ ^ tishicircles, and is somewhat similar in outline to that o ^ thewhence its name. This form is commonly £' ve ” t ionsauricola, or nimbus of glory, in which the represen ‘saints are enclosed.
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