What the instinct for symmetry means, philosophers may be left to explain; but that it does exist, that it means something, and that it is most strongly developed in those races which have reached the highest artistic civilization, must be acknowledged by all students of sociology. It is, therefore, not superfluous to point out that, in interior decoration as well as in architecture, a regard for symmetry, besides satisfying a legitimate artistic requirement, tends to make the average room not only easier to furnish, but more comfortable to live in.

As the effect produced by a room depends chiefly upon the distribution of its openings, it will be well to begin by considering the treatment of the walls. It has already been said that the decorator can often improve a room, not only from the artistic point of view, but as regards the comfort of its inmates, by making some slight change in the position of its openings. Take, for instance, a library in which it is necessary to put the two principal bookcases one on each side of a door or fireplace. If this opening is in the centre of one side of the room, the wall-decorations may be made to balance, and the bookcases may be of the same width, - an arrangement which will give to the room an air of spaciousness and repose. Should the wall-spaces on either side of the opening be of unequal extent, both decorations and bookcases must be modified in size and design; and not only does the problem become more difficult, but the result, because necessarily less simple, is certain to be less satisfactory. Sometimes, on the other hand, convenience is sacrificed to symmetry; and in such cases it is the decorator's business to remedy this defect, while preserving to the eye the aspect of symmetry. A long narrow room may be taken as an example.

If the fireplace is in the centre of one of the long sides of the room, with a door directly opposite, the hearth will be without privacy and the room virtually divided into two parts, since, in a narrow room, no one cares to sit in a line with the doorway. This division of the room makes it more difficult to furnish and less comfortable to live in, besides wasting all the floor-space between the chimney and the door. One way of overcoming the difficulty is to move the door some distance down the long side of the room, so that the space about the fireplace is no longer a thoroughfare, and the privacy of the greater part of the room is preserved, even if the door be left open. The removal of the door from the centre of one side of the room having disturbed the equilibrium of the openings, this equilibrium may be restored by placing in a line with the door, at the other end of the same side-wall, a piece of furniture corresponding as nearly as possible in height and width to the door. This will satisfy the eye, which in matters of symmetry demands, not absolute similarity of detail, but merely correspondence of outline and dimensions.

It is idle to multiply examples of the various ways in which such readjustments of the openings may increase the comfort and beauty of a room. Every problem in house decoration demands a slightly different application of the same general principles, and the foregoing instances are intended only to show how much depends upon the placing of openings and how reasonable is the decorator's claim to have a share in planning the background upon which his effects are to be produced.

It may surprise those whose attention has not been turned to such matters to be told that in all but the most cheaply constructed houses the interior walls are invariably treated as an order. In all houses, even of the poorest kind, the walls of the rooms are finished by a plain projecting board adjoining the floor, surmounted by one or more mouldings. This base, as it is called, is nothing more nor less than the part of an order between shaft and floor, or shaft and pedestal, as the case may be. If it be next remarked that the upper part of the wall, adjoining the ceiling, is invariably finished by a moulded projection corresponding with the crowning member of an order, it will be clear that the shaft, with its capital, has simply been omitted, or that the uniform wall-space between the base and cornice has been regarded as replacing it In rooms of a certain height and importance the column or pilaster is frequently restored to its proper place between base and cornice; but where such treatment is too monumental for the dimensions of the room, the main lines of the wall-space should none the less be regarded as distinctly architectural, and the decoration applied should be subordinate to the implied existence of an order. (For the application of an order to walls, see Plates XLII and L).

Where the shafts are omitted, the eye undoubtedly feels a lack of continuity in the treatment: the cornice seems to hang in air and the effect produced is unsatisfactory. This is obviated by the use of panelling, the vertical lines carried up at intervals from base to cornice satisfying the need for some visible connection between the upper and lower members of the order. Moreover, if the lines of the openings are carried up to the cornice (as they are in all well-designed schemes of decoration), the openings may be considered as intercolumniations and the intermediate wall-spaces as the shafts or piers supporting the cornice.

In well-finished rooms the order is usually imagined as resting, not on the floor, but on pedestals, or rather on a continuous pedestal. This continuous pedestal, or "dado" as it is usually called, is represented by a plinth surmounted by mouldings, by an intermediate member often decorated with tablets or sunk panels with moulded margins, and by a cornice. The use of the dado raises the chief wall-decoration of the room to a level with the eye and prevents its being interrupted or concealed by the furniture which may be placed against the walls. This fact makes it clear that in all well-designed rooms there should be a dado about two and a half feet high. If lower than this, it does not serve its purpose of raising the wall-decoration to a line above the furniture; while the high dado often seen in modern American rooms throws all the rest of the panelling out of scale and loses its own significance as the pedestal supporting an order.