In the general effect of the room, the form of the ceiling is of more importance than its decoration. In rooms of a certain size and height, a flat surface overhead looks monotonous, and the ceiling should be vaulted or coved.1 Endless modifications of this form of treatment are to be found in the architectural treatises of the seventeenth and eighteenth centuries, as well as in the buildings of that period.

A coved ceiling greatly increases the apparent height of a low-studded room; but rooms of this kind should not be treated with an order, since the projection of the cornice below the springing of the cove will lower the walls so much as to defeat the purpose for which the cove has been used. In such rooms the cove should rise directly from the walls; and this treatment suggests the important rule that where the cove is not supported by a cornice the ceiling decoration should be of very light character. A heavy panelled ceiling should not rest on the walls without the intervention of a strongly profiled cornice. The French Louis XV decoration, with its fanciful embroidery of stucco ornament, is well suited to coved ceilings springing directly from the walls in a room of low stud; while a ceiling divided into panels with heavy architectural mouldings, whether it be flat or vaulted, looks best when the walls are treated with a complete order.

1The flat Venetian ceilings, such as those in the ducal palace, with their richly carved wood-work and glorious paintings, beautiful as they have been made by art, are not so fine architecturally as a domed or coved ceiling.

Durand, in his lectures on architecture, in speaking of cornices lays down the following excellent rules: "Interior cornices must necessarily differ more or less from those belonging to the orders as used externally, though in rooms of reasonable height these differences need be but slight; but if the stud be low, as sometimes is inevitable, the cornice must be correspondingly narrowed, and given an excessive projection, in order to increase the apparent height of the room. Moreover, as in the interior of the house the light is much less bright than outside, the cornice should be so profiled that the juncture of the mouldings shall form not right angles, but acute angles, with spaces between the mouldings serving to detach the latter still more clearly from each other".

The choice of the substance out of which a ceiling is to be made depends somewhat upon the dimensions of the room, the height of the stud and the decoration of the walls. A heavily panelled wooden ceiling resting upon walls either frescoed or hung with stuff is likely to seem oppressive; but, as in all other kinds of decoration, the effect produced depends far more upon the form and the choice of ornamental detail than upon the material used. Wooden ceilings, however, both from the nature of the construction and the kind of ornament which may most suitably be applied to them, are of necessity rather heavy in appearance, and should therefore be used only in large and high-studded rooms the walls of which are panelled in wood.1 l For an example of a wooden ceiling which is too heavy for the wall-decoration below it, see Plate XLIV.

Stucco and fresco-painting are adapted to every variety of decoration, from the light traceries of a boudoir ceiling to the dome of the salon a l'ltalienne; but the design must be chosen with strict regard to the size and height of the room and to the proposed treatment of its walls. The cornice forms the connecting link between walls and ceiling and it is essential to the harmony of any scheme of decoration that this important member should be carefully designed. It is useless to lavish money on the adornment of walls and ceiling connected by an ugly cornice.

The same objections extend to the clumsy plaster mouldings which in many houses disfigure the ceiling. To paint or gild a ceiling of this kind only attracts attention to its ugliness. When the expense of removing the mouldings and filling up the holes in the plaster is considered too great, it is better to cover the bulbous rosettes and pendentives with kalsomine than to attempt their embellishment by means of any polychrome decoration. The cost of removing plaster ornaments is not great, however, and a small outlay will replace an ugly cornice by one of architectural design; so that a little economy in buying window-hangings or chair-coverings often makes up for the additional expense of these changes. One need only look at the ceilings in the average modern house to see what a thing of horror plaster may become in the hands of an untrained "designer".

The same general principles of composition suggested for the treatment of walls may be applied to ceiling-decoration. Thus it is essential that where there is a division of parts, one part shall perceptibly predominate; and this, in a ceiling, should be the central division. The chief defect of the coffered Renaissance ceiling is the lack of this predominating part Great as may have been the decorative skill expended on the treatment of beams and panels, the coffered ceiling of equal-sized divisions seems to press down upon the spectator's head; whereas the large central panel gives an idea of height that the great ceiling-painters were quick to enhance by glimpses of cloud and sky, or some aerial effect, as in Mantegna's incomparable ceiling of the Sala degli Sposi in the ducal palace of Mantua.

Ceiling-decoration should never be a literal reproduction of wall-decoration. The different angle and greater distance at which ceilings are viewed demand a quite different treatment and it is to the disregard of this fact that most badly designed ceilings owe their origin. Even in the high days of art there was a tendency on the part of some decorators to confound the two plane surfaces of wall and ceiling, and one might cite many wall-designs which have been transferred to the ceiling without being rearranged to fit their new position. Instances of this kind have never been so general as in the present day. The reaction from the badly designed mouldings and fungoid growths that characterized the ceilings of forty years ago has led to the use of attenuated laurel-wreaths combined with other puny attributes taken from Sheraton cabinets and Adam mantel-pieces. These so-called ornaments, always somewhat lacking in character, become absolutely futile when viewed from below.