ARCHITECTURE. 



of walls, but aiso Iii the cutting of stones 

 with geometrical exactness, so as to fit 

 vaulted surfaces, of variously formed fi- 

 gures. 



Iron is used for cramping stones, some- 

 times in binding the face and back of a 

 wall together, when there is little heart. 

 In domes it is frequently used in circular 

 chains, in order to remove lateral pres- 

 sure, and make the weight of the super- 

 structure act perpendicularly upon the 

 supports. It is also used in fastening 

 wood together, and wood to stone work. 



Timber is used .also as ligatures to 

 walls? in this situation it is called bond 

 timber, which also serves for securing 

 the internal finishings. Timber is fre- 

 quently used in foundations, in floors, in 

 roofing, in internal finishing, &c. Tim- 

 ber, besides being used in bond, flooring, 

 and roofing, in conjunction with stone or 

 brickwork, is sometimes used as the only 

 material, excepting the chimnies, nails, 

 and other iron fastenings. 



Mouldings. In architectural decora- 

 tions, the materials are formed into a va- 

 riety of shapes; which have in any two 

 places sections of equal and similar fi- 

 gures, at right angles to their surface, in 

 these two places ; thin forms of this pro- 

 perty are called mouldings. 



When the section is semicircular, or 

 semieiliptical, it is called a torus or astra- 

 gal : when large, it is called a torus ; and 

 when small, an astragal. 



When the section is a concave curve, 

 and when the concavity recedes beyond 

 either of the extremities of the curve, 

 the moulding is called a scotia or trochilus. 



When the section is concave, one ex- 

 tremity being above the other, and the 

 upper extremity projecting out beyond 

 the lower, and when the lower extremity 

 recedes from a vertical line, equal to the 

 greatest recess of the concavity, or more, 

 the moulding is called a cavetto. 



When the section is a convex curve 

 with one extremity below the other, and 

 the upper extremity projecting farther 

 than the lower, without any part of the 

 convexity being lower than the lower ex- 

 tremity of the section, the moulding is 

 called an ovolo or echinus. 



When the section is a curve of contra- 

 ry flexure, like a flat S, the moulding is 

 called an ogee ; and when the concave 

 part of the ogee projects, and the convex 

 part recedes, the ogee in this position is 

 called a sima recta ; but when the parts 

 lie the contrary way, it is called a sima 

 inversa. 



When the section is straight, and is 

 Gather perpendicular to the horizon, or 



nearly so, then the flat member is called 

 a fillet, plat-band, or facia, according to 

 its breadth and comparison with other 

 contiguous mouldings. 



When it is very narrow, and either 

 crowns an upper moulding, or divides 

 one member from another, it is called a 

 fillet, or listello ; when it is broader, it is 

 called a plat-band or plinth ; and when 

 very broad, it is called a facia or face. 



Compound Mouldings. When one, two, 

 or a collection of mouldings, with or with- 

 out fillets, crown a broad, flat member, 

 this collection is called a cymatium. 

 Other names are particularly applied to 

 the orders, and are explained under that 

 head. 



ORDERS OP ARCHITECTURE. 



An order is a decorated imitation of 

 those primitive huts, which consisted of 

 rows of posts, made of the trunks of trees, 

 disposed in the ground around a quadran- 

 gular plat, and supporting 1 a covering, 

 which consisted of four lintelling beams, 

 placed on the top of the posts, with other 

 transverse beams, supported again by two 

 of the opposite lintels : and lastly, of 

 three rows of transverse timbers support- 

 ing each other, and the lowermost sup- 

 ported by the ends of the transverse 

 beams on each side, i;i parallel inclined 

 planes, rising from the ends of the trans- 

 verse beams, till each plane of timbers on 

 the one side met its corresponding plane 

 on the other; the lowermost timbers on 

 each side being disposed in pairs, in the 

 same vertical planes with the transverse 

 beams forming the sides of the triangle, 

 and projecting beyond the lintels, and the 

 uppermost inclined planes of timbers 

 serving to fix the covering of tyle or 

 stone. From this simple construction 

 arose the first order of architecture, call- 

 ed 



Doric Order. The columns were imi- 

 tated from the wooden posts tapering up- 

 wards, as trees do by nature, and placed 

 upon a stone base, to prevent them from 

 sinking : vertical channels, or flutes, were 

 cut in the shafts, to hold the spears, or 

 staves, which the early Greeks carried 

 along with them. The capital was form- 

 ed by circular stones, laid on the tops of 

 the columns, and square ones again upon 

 these, to protect the shafts from rain, and 

 to receive the lintelling beam, which be- 

 came the architrave : the ends of the 

 joists over the architrave were not in ver- 

 tical channels, forming the tri glyphs, for 

 preventing the rain from adhering to 

 mem. The cornice was formed by the 



