The Nature and Distribution of Light
In determining the nature and distribution of light desirable in a given room, and the height of tone desirable in its various colored surfaces, the general problem of the decorator is five-fold. He must determine (a) the intensity and character of illumination most fitting for the particular room to be lighted; (b) the height of tone desirable for the background surfaces; (c) the distribution of light and dark tones as to position in the room; (d) their distribution as to relative area; and (e) the distance by which the principal and secondary tones must be separated in order to yield the maximum esthetic effect.
The first consideration was discussed in an earlier paragraph of this chapter, wherein it appeared that within the limits imposed by the physical comfort of the eye the amount and brilliancy of the light desirable in a given room will depend upon the function of the room, and hence upon the motive of its decorative treatment.
PLATE VIII.- Wing chair in which the flow of curved line is abruptly broken by the use of straight legs and base. Note the difference in richness between plain and ornamented surfaces by comparing this chair with the one in Plate VII.
If we conceive of the entire range of values from carbon black to the dazzling white of the diamond or of sunlit snow as forming a scale of one hundred and fifty degrees, with black at o and dazzling white at 150, the white of white paper or white paint will lie at 100, gray at 50, dark gray at 25, and light gray at 75, as in Figure 43. On this scale light gray appears midway between the two extremes, and while colored surfaces having the luminosity of light gray are markedly brighter than those characteristic of outdoor nature, long experiment and observation have shown that they are most agreeable when used indoors. Light gray seems to be the degree of brightness which the eye finds least fatiguing, and to which our nerves seem best adapted. Since the walls lie immediately before the eye, the wall colors, whatever their hues, will normally approximate rather closely to light gray in tone. We will lower the tone of the walls in rooms where a marked effect of tranquillity is aimed at, and raise it in rooms where a marked effect of gayety and animation is desired. But in general this is the ideal toward which the decorator will work; and in so working he is concerned, as we have just noted, with two important factors: the amount of natural or artificial light available, and the luminosity of the hues with which he works.
FIGURE 43.- A scale of tone relationships, from black, as of black paint, to the white of sunlit snow or the diamond.
As to the distribution of light and shade according to position in the room, the fundamental fact here as everywhere in decorative composition is that beauty can appear only in the presence of unity in variety; and here, as everywhere, unity must be insured through the repetition of like elements and the predominance of one element. This consideration was discussed in the chapter on contrast, wherein it appeared that in the treatment of the background surfaces of the room three zones or registers of closely-related tones best satisfy the requirements of the mind, with the darkest zone at the floor, the lightest at the ceiling, and the mid-zone on the walls. It remains to ascertain what relative areas best please the mind, and how far apart in tone the three zones should be.
Sir Joshua Reynolds noted that the great Venetian colorists gave about one-fourth of each canvas to the lights, including the principal and secondary lights, about one-fourth to the shadows, and the remaining one-half to the mid-tones. This constitutes an excellent ideal toward which to work in interior decoration. In superficial area, before color is applied, the floor and ceiling of a room are equal, and together they are approximately equal to the wall area, including the openings. In practice there is wide room for variations in these proportions. The area of darks is reduced by the margin around the rug unless the floor is stained to a dark tone, and increased by dark furniture and furniture coverings and hangings; while the area of mid-tones is of course correspondingly reduced. Accordingly, it is the problem of the decorator-and a very simple one, if well considered-to choose and distribute his light and dark tones, of whatever hue, in such a way that the half-tones are plainly preponderant and as nearly as practicable equal to the total of both light and dark.
For example, in a room eighteen feet long, twelve feet wide, and nine feet high, the floor and ceiling areas would be 216 square feet each, or a total of 432 square feet, and the total wall areas, including the openings, 540 square feet. If the walls were done in tan of the luminosity of light gray, the ceiling in light cream, and the floor in golden brown of the luminosity of gray, while the windows were curtained with net or casement cloth to match the walls in tone, the half-tones would be clearly dominant and, in fact, considerably in excess of the esthetic requirement. If, however, four windows and two doors to adjoining rooms were hung with draperies to match the carpet in tone, averaging twenty-four square feet of exposed surface to each opening, and if the piano, bookcase and chairs appearing against the walls were of dark wood and had an aggregate of fifty square feet, the total of lights and darks would exceed 600 square feet, while the total of half-tones would be less than 350 square feet. In fact, the darks alone would slightly exceed the half-tones, thus destroying the unity and marring the beauty of the room by eliminating the dominant element. In this situation it would be necessary to substitute lighter hangings-for example, a printed linen of which one-fourth only of the area was dark-or to resort to some similar device or devices to correct the faulty distribution of the first arrangement.
In reference to the last consideration, it may be noted again that tone contrasts, whether between two back- ground areas, between a decorative object and its background, or among the parts of a single unit, ought to be clearly perceptible but not so sharp that the mind fails to perceive as well the elements of tone likeness. A room in which the tone contrast between floor and wall or wall and ceiling is too slight, is in general only less unpleasant than one in which it is too marked. In the one case there is an effect of instability and lack of poise; in the other, of abruptness and lack of suavity. In order to enter most effectively into a harmony the three background surfaces, whatever their hues, should be about twenty-five degrees, or, in special situations, twenty or even fifteen degrees apart in tone. Thus colors having the luminosity of gray, light gray and gray-white, or of dark gray, gray and light gray, combine harmoniously when used on the floor, walls and ceiling, respectively. Of course this is not to be taken as an invariable rule, for there are no invariable rules in artistic practice. It is frequently modified widely to suit particular requirements, as when a ceiling is darkened to give strength or repose to a room, or when black and white or very dark and very light are used together in the decoration of a sun room or some other little-used apartment for the sake of vigor or brilliancy of effect; but in general it is a safe guide to restful and permanently agreeable results.
PLATE IX.- A drawing room characterized by pleasing textures and tone relationships, the latter somewhat altered in the photograph. The restraint of the panelled background is relieved and endowed with a quality of animation and buoyancy by small, slenderly-proportioned furniture, and by the free use of warm color in the accessories.