In buildings, where beauty and magnifi cence are preferred to economy, the halls and galleries may be raised, making them occupy two stories. Saloons arc frequent ly raised three stories, orthe whole height of the building, and have galleries around their interior at the height of the floors, for communicating with the various parts of the building.
When rooms are adorned with an en tire order, the entablature may occupy in height from one-sixth to one-seventh of that of the room ; if the entablature be without columns, it may have from one seventh to one-eighth. If a cornice, frize, and astragal, are executed, its height may be equal to a tenth ; and if only a cornice, its height May be from a twentieth to a thirtieth part of that of the room. In general, all interior proportions and deco rations must be less, and more delicate than those of the exterior. Architraves, in most cases, should not be above one seventh of the width.
Ceilings. The figures of ceilings are either flat or coved : coved ceilings either have a concavity around the margins, and are flat in the middle, or have a vaulted surface. (See Vact.rs). Ceilings, that are coved and flat, may occupy from one-fifth to a fourth part of the height of the room : the principal sections of vaulted ceilings may be of various seg ments, equal to, or less than semicircles, as may be most suitable to the height of the room. Flat ceilings are adorned with large compartments, or foliages, and other ornaments, or with both. Compartment ceilings are either formed by raising mouldings on the surface; or by depress ing the 'runnels within the moulded enclo sure, which may be partly raised upon, and partly recessed within the framing, or entirely recessed: the figures of the pannels may either be polygonal, circular, or elliptical. The ceilings of the porti cos and of the interior of ancient temples arc comparted, and the pannels deeply recessed ; the prominent parts between them representing the ancient manner of framing the beams of wood which com posed the floors; the mouldings on the sides of the pannels arc sunk, by one, two, or several degrees, like inverted steps, :incline bottoms of pannels are most frequently decorated with roses ; the figures of these compartments are mostly equilateral, and equiangular. Triangles were seldom used, but we find squares, hexagons, and octagons, in great abun dance. The framing around the paimels in Roman antiquity is constantly parallel, or of equal breadth, therefore, when squares are introduced, there is no other variety; but hexagons will join in conti guity with one another, or form the in terstices into lozenges, or equilateral tri angles. Octagons naturally form two va
rieties, pi_. that of their own figure, and squares in the interstices : this kind of compartment is called coffering, and the recessed parts coffers, which are used not only in plain ceilings, but also in cylindri cal vaults. The borders of the coffer ing are generally terminated with belts, charged most frequently with foliage ; and sometimes again the foliage is bor dered with guillochis, as in the temple of Peace at Rome. In the ceiling of the entire temple at Balbec, coffers are dis posed around the cylindrical vault, in one row rising over each intercolumn ; and between everyrow of coffers is a project ing belt, ornamented with a guillochi, corresponding with two semi-attached co lumns in the same vertical plane, one co lumn supporting each springing of the belt. The moderns also follow. the same practice in their cupolas and cradle vaults, ornamenting them with coffers and belts : the belts are ornamented with frets, guillochis, or foliages; small parmels are ornamented with roses, and large ones with foliage, or historical subjects, in a variety of different manners.
The grounds may be gilt and the or naments add te, partly coloured, or streak ed with gold ; or the ornaments may be gilt and the grounds white, pearl, straw colour, light-blue, or any tint that may agree best with the ornaments. Some ceilings are painted either wholly, or in various compartments only : when a ceil ing is painted in representation of a sky, it ought either to be upon a plane or spheric surfitee. A ceiling coved and fiat, with the plane painted to represent the sky, is extremely improper, as the cove represents the half of an arch upon every side of the room, it will seem as if falling, from the want of an apparent sup port in the middle, unless the ceiling rise from a circular plan. Ceilings coved and Nat are much employed in modern apart ments: they seem to be a kind of medi um between the horizontal and the vari ous arched forms practised by the an cients : they do not require so much height as the latter, but they are neither so graceful nor so grand. Vaulted ceil ings are more expensive than plane ones, but they arc also susceptible of a greater variety of embellishments.