CAS

110

CAS

Another material which, until very recently, was entirelyunknown to us, but which, since its first introduction, hascome into extensive use, threatens to prove a formidablerival to the above-mentioned articles—we allude to GuttaPercha. This substance has not been tested sufficiently toallow us to speak decidedly as to its applicability to the pur-poses we are considering; it is moulded into cornices, panels,and other forms of architectural decoration, and is on manyaccounts eligible for such uses; it can be moulded, cast,stamped, or embossed, into any form however elaborate, andis susceptible of colour; it has, however, disadvantages whichfor the present must preclude its employment; for, althoughit promises considerable hardness, it is readily injured bycontact with any sharp body; besides this, it is liable tosoften and liquify when exposed to an elevated temperature.This last defect has been modified by a process to which thematerial is subjected in its manufacture, which is termedmetallo-thionising, but still it has not been entirely removed.The properties of this production, however, have not yetbeen sufficiently developed to decide upon its capabilities;many improvements will doubtless be introduced into itsmanufacture, as its nature becomes more fully understood.

Cast, among plumbers, a little brazen funnel at one endj of a mould, for casting pipes without soldering, throughwhich the melted metal is poured into the mould.

Cast, Rough. See Rough Cast.

I CASTELLA, or Castles, in British antiquity, one of theI three kinds of fortifications built along the line of the wallof Severus, the other two sorts being denominated stations andtowers. The Castella were neither so large nor strong as thestations, but much more numerous, there being in this wall nofewer than 81. The figure of the castellum was cubical, 66feet in each dimension, fortified on every side by thick andlofty walls, but without any ditch, except on the north side,where also the wall was raised much above its generalheight, and with the adjoining ditch formed the fortification.The castella were placed in the intervals between the stations,generally at the distance of about seven furlongs from eachother, and guards were constantly kept in them, consisting ofa certain number of men, detached from the nearest stations.See Castle .

Castella, in Roman antiquity, also denoted the reservoirs,in which the waters from the aqueducts were collected, whencethe city was supplied by leaden pipes.

CASTELLATED HOUSES, those mansions which suc-; ceeded the castles and fortified residences of the feudal| | barons; they still preserved the appearance of strength,although in reality incapable of defence against a regularforce. These buildings were provided with battlements andturrets, rather for ornament, however, than for practicalpurposes.

The windows are generally closed horizontally with labelsover them; the apertures are sometimes divided by mullions,consisting of one or more munnions in the breadth, and oneor two transoms in the height, by which the great opening isdivided into several smaller apertures, sometimes arched underthe lintels, and sometimes also under the transoms. One ofthe most remarkable of these edifices is Haddon-Hall, Derby-shire .

CASTING, the act of taking the impression of any sur-face, whether plain or sculptured, by pouring a liquid matteron that surface. See Cast.

Casting, in joinery and carpentry, is said of a piece oftimber, when its sides are bent or twisted from their originalsurfaces, by the fibres being unequally heated, dried, ormoistened ; or by being naturally disposed in different direc-tions ; or the twist may, perhaps, arise from different degrees

of hardness in the body, occasioned by knots, &c. This eff eCis otherwise called warping.

Casting of Bbick or Stone Walls. See Rough CaS*-Casting of Bronzes , is thus performed: The figure to y ^cast from must have a mould made on it, consisting of a inlX fture of plaster-of-paris and brick-dust, in the proportionnot more than one-third of the former, to two-tliirds of * ’latter. The thickness of this mould must be according to 1length and breadth, in order to be sufficiently strong. In*channels, tending upwards, should be cut in various parts ot *joints, to give vent to the air forced out by the metal as it r ainto -the mould. After the mould is made, a thin layer of cl ‘ *is spread smoothly and uniformly over its inner surface, ot 1intended thickness of the bronze; the mould is then clos*^’and its cavity filled with a composition of two-thirds briodust and one-third plaster, mixed with water, to form the coi®’previous to which, should the work be of any magnitude^will be necessary to insert strong iron bars within the m 0 ® Jto secure it from accidents, and to facilitate the remora

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the core. The mould being then opened, andremoved, is with the core thoroughly dried; to effect ^more perfectly, they are exposed to the action of a charefire or lighted straw ; great attention is required to this P"of the process, for should the least moisture be suffer® 1 *remain, the mould will burst, and the cast be blown to P' eC ’to the great danger of the lives or limbs of the work® 1 jW hen the mould is finally closed, the cord must be supp° rin its place by short bars of bronze, running from the m®into the core. The whole then is bound round with 1 ^bars, proportioned in strength to the weight of the cast, jlaid in a proper situation for receiving the metal, supP° rby dry materials, as sand-stones, &c. to prevent accW e ...

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In placing the mould, due care must be taken to con no- ^mouth with the reservoirs, by means of a channelinclined plane, that the liquid metal may run freely- s6form of the furnace, and mode of running, are similar topractised in bell-founding.

Casting of Lead. See Plumbing. . of

CASTLE (from the Latin , castellum, a diminuti'^jcastrum), in ancient writers, a town or village surro ^with a ditch, and wall furnished with towers at interval >guarded by a body of troops. £ 0 rt,

Castellum originally seems to have signified a small er ^for a little garison. Though Suetonius uses the wordthe fortification was large enough to contain a cohort. ^

According to Vegetius , the castella were often, like ^

built on the borders of the empire, where there we restant guards, and fences against the enemy.

Horsley takes them for much the same with wha*otherwise denominated stations. See Castella. . . r V]Castle, in a modern sense, is a place fortified e Ti>ie innature or by art, in a city or country, to keep the P e °P g jv0their duty, or to resist an enemy. In the more eX *® j g ofinterpretation of the word, it includes the various met 1 jjedencampment, but in its stricter meaning, it is usually a *£ e 9 sto buildings walled with stone, and intended for resid ^,.0well as for defence. Few branches of historical reseabeen so little attended to, as that which relates to militaty^g oftecture. Castles, indeed, such as we now see thein ’kVlate introduction to the world. Whether we may rawith the accommodations of life brought by the ei u,!/from the East, is doubtful: but thus much seemscertain, that it was in France, England, Germany ; y a ;le<Iland, and Savoy, that the system of castellation first pr g; c jl/>In Italy, till the Normans got possession of Naples ancastles were comparatively few. We may at *® atheir general adoption in Europe with the feudal 1