From an esthetic or, more broadly, a psychological point of view no medium rivals light in expressiveness. Not only is light allied with man's most important sense but throughout long ages of associations and uses mankind has bestowed upon it many attributes. In fact, it is possible that light, color, and darkness possess certain fundamentally innate powers; at least, they have acquired expressive and impressive powers through the many associations in mythology, religion, nature, and common usage. Besides these attributes, light possesses a great advantage over the media of decoration in obtaining brightness and color effects. For example, the landscape artist cannot reproduce the range of values or brightnesses in most of nature's scenes, for if black is used to represent a deep shadow, white is not bright enough to represent the value of the sky. In fact, the range of brightnesses represented by the deep shadow and the sky extends far beyond the range represented by black and white pigments. The extreme contrast ordinarily available by means of artist's colors is about thirty to one, but the sky is a thousand times brighter than a shadow, a sunlit cloud is thousands of times brighter than the deep shadows of woods, and the sun is millions of times brighter than the shadows in a landscape.The range of brightnesses obtainable by means of light extends from darkness or black throughout the range represented by pigments under equal illumination and beyond these through the enormous range obtainable by unequal illumination of surfaces to the brightnesses of the light-sources themselves. In the matter of purity of colors, light surpasses reflecting media, for it is easy to obtain approximately pure hues by means of light and to obtain pure spectral hues by resorting to the spectrum of light. It is impossible to obtain pure hues by means of pigments or of other reflecting media. These advantages of light are very evident on turning to spectacular lighting effects, and even the lighting of interiors illustrates a potentiality in light superior to other media. For example, in a modern interior in which concealed lighting produces brilliantly illuminated areas above a cornice and dark shadows on the under side, the range in values is often much greater than that represented by black and white, and still there remains the possibility of employing the light-sources themselves in extending the scale of brightness. Superposing color upon the whole it is obvious that the combination of "primary" light with reflected light possesses much greater potentiality than the latter alone. This potentiality of light is best realized if lighting is regarded as "painting with light" in a manner analogous to the decorator's painting with pigments, etc.

The expressive possibilities of lighting find extensive applications in relation to painting, sculpture, and architecture. A painting is an expression of light and the sculptor's product finally depends upon lighting for its effectiveness. Lighting is the master painter and sculptor. It may affect the values of a painting to some extent and it is a great influence upon the colors. It molds the model from which the sculptor works and it molds the completed work. The direction, distribution, and quality of light influence the appearance of all objects and groups of them. Aside from the modeling of ornament, the light and shade effects of relatively large areas in an interior such as walls and ceiling, the contrasts in the brightnesses of alcoves with that of the main interior, and the shadows under cornices, beams, and arches are expressions of light.

The decorator is able to produce a certain mood in a given interior by varying the distribution of values and the choice of colors and the lighting artist is able to do likewise, but the latter is even able to alter the mood produced by the decorator. For example, a large interior flooded with light from concealed sources has the airiness and extensiveness of outdoors. If lighted solely by means of sources concealed in an upper cornice, the ceiling may be bright and the walls may be relatively dark by contrast. Such a lighting effect may produce a feeling of being hemmed in by the walls without a roof. If the room is lighted by means of chandeliers hung low and equipped with shades in such a manner that the lower portions of the walls may be light while the upper portions of the interior may be ill defined, the feeling produced may be that of being hemmed in by crowding darkness. Thus lighting is productive of moods and illusions ranging from the mystery of crowding darkness to the extensiveness of outdoors.Future lighting of interiors doubtless will provide an adequacy of lighting effects which will meet the respective requirements of various occasions. A decorative scheme in which light and medium grays are employed produces an interior which is very sensitive to lighting effects. To these light-and-shade effects colored light may add its charming effectiveness. Not only are colored lighting effects able to add much to the beauty of the setting but they possess certain other powers. Blue tints produce a "cold" effect and the yellow and orange tints a "warm" effect. For example, a room will appear cooler in the summer when illuminated by means of bluish light and a practical application of this effect is in the theater which must attract audiences in the summer. How tinted illuminants fit the spirit of an occasion or the mood of a room may be fully appreciated only through experiments, but these are so effective that the future of lighting will witness the application of the idea of "painting with light" to its fullest extent. Color is demanded in other fields, and, considering its effectiveness and superiority in lighting, it will certainly be demanded in lighting when its potentiality becomes appreciated and readily utilized.

The expressiveness of light is always evident in a landscape. On a sunny day the mood of a scene varies throughout the day and it grows more enticing and agreeable as the shadows lengthen toward evening. The artist in painting a desert scene employs short harsh shadows if he desires to suggest the excessive heat. These shadows suggest the relentless noonday sun. The overcast sky is universally depressing and it has been found that on a sunny day most persons experience a slight depression when a cloud obscures the sun. Nature's lighting varies from moment to moment, from day to day, and from season to season. It presents the extremes of variation in distributions of light from overcast to sunny days and in the latter cases the shadows are continually shifting with the sun's altitude. They are harshest at noon and gradually fade as they lengthen, until at sunset they disappear. The colors of sunlit surfaces and of shadows vary from sunrise to sunset. These are the fundamental variations in the lighting, but in the various scenes the lighting effects are further modified by clouds and by local conditions or environment. The vast outdoors provides a fruitful field for the study of the expressiveness of light.

Having become convinced of this power of light, the lighting expert may turn to artificial light, which is so easily controlled in direction, distribution, and color, and draw upon its potentiality. Not only is it easy to provide a lighting suitable to the mood or to the function of an interior but it is possible to obtain some variety in effect so that the lighting may always suit the occasion. A study of nature's lighting reveals one great principle, namely, variety. Mankind demands variety in most of his activities. Work is varied and alternated with recreation. Meals are not always the same. Clothing, decorations, and furnishings are relieved of monotony. One of the most potent features of artificial light is the ease with which variety may be obtained. In obtaining relief from the monotony of decorations and furnishings, considerable expense and inconvenience are inevitably encountered. With an adequate supply of outlets, circuits, and controls a wide variety of lighting effects may be obtained with perhaps an insignificant increase in the initial investment. Variety is the spice of lighting as well as of life.

These various principles of lighting are readily exemplified in the lighting of the home, which is discussed in another chapter. The church is even a better example of the expressive possibilities of lighting. The architectural features are generally of a certain period and first of all it is essential to harmonize the lighting effect with that of the architectural and decorative scheme. Obviously, the dark-stained ceiling of a certain type of church would not be flooded with light. The fact that it is made dark by staining precludes such a procedure in lighting. The characteristics of creeds are distinctly different and these are to some extent exemplified by the lines of the architecture of their churches. In the same way the lighting effect may be harmonized with the creed and the spirit of the interior. The lighting may always be dignified, impressive, and congruous. Few churches are properly lighted with a high intensity of illumination; moderate lighting is more appropriate, for it is conducive to the spirit of worship. In some creeds a dominant note is extreme penitence and severity. The architecture may possess harsh outlines, and this severity or extreme solemnity may be expressed in lighting by harsher contrasts, although this does not mean that the lighting must be glaring. On the other hand, in a certain modern creed the dominant note appears to be cheerfulness. The spacious interiors of the churches of this creed are lacking in severe lines and the walls and ceilings are highly reflecting. Adequate illumination by means of diffused light without the production of severe contrasts expresses the creed, modernity, and enlightenment. On the altar of certain churches the expressiveness of light is utilized in the ceremonial uses which vary with the creed. Even the symbolism of color may be appropriately woven into the lighting of the church.

The expressiveness of light and color originated through the contact of primitive man with nature. Sunlight meant warmth and a bountiful vegetation, but darkness restricted his activities and harbored manifold dangers. Many associations thus originated and they were extended through ignorance and superstition. Yellow is naturally emblematical of the sun and it became the symbol of warmth. Brown as the predominant color of the autumn foliage became tinctured with sadness because the decay of the vegetation presaged the death of the year and the cold dreary months of winter. The first signs of green vegetation in the spring were welcomed as an end of winter and a beginning of another bountiful summer; hence green symbolized youth and hope. It became associated with the springtime of life and thus signified inexperience, but as the color of vegetation it also meant life itself and became a symbol of immortality. Blue acquired certain divine attributes because, as the color of the sky, it was associated with the abode of the gods or heaven. Also a blue sky is the acme of serenity and this color acquired certain appropriate attributes.

Associations of this character became woven into mythology and thus became firmly established. Poets have felt these influences of light and color in nature and have given expression to them in words. They also have entwined much of the mythology of past civilizations and these repetitions have helped to establish the expressiveness of light and color. Early ecclesiasts employed these symbolisms in religious ceremonies and dictated the garbs of saints and other religious personages in the paintings which decorated their edifices. Thus there were many influences at work during the early centuries when intellects were particularly susceptible through superstition and lack of knowledge. The result has been an extensive symbolism of light, color, and darkness.

At the present time it is difficult to separate the innate appeal of light, color, and darkness from those attributes which have been acquired through associations. Possibly light and color have no innate powers but merely appear to have because the acquired attributes have been so thoroughly established through usage and common consent. Space does not permit a discussion of this point, but the chief aim is consummated if the existence of an expressiveness and impressiveness of light is established. There are many other symbolisms of color and light which have arisen in various ways but it is far beyond the scope of this book to discuss them.

Psychological investigations reveal many interesting facts pertaining to the influence of light and color upon mankind. When choosing color for color's sake alone, that is, divorced from any associations of usage, mankind prefers the pure colors to the tints and shades. It is interesting to note that this is in accord with the preference exhibited by uncivilized beings in their use of colors for decorating themselves and their surroundings. Civilized mankind chooses tints and shades predominantly to live with, that is, for the decoration of his surroundings. However, civilized man and the savage appear to have the same fundamental preference for pure colors and apparently culture and refinement are responsible for their difference in choice of colors to live with. This is an interesting discovery and it has its applications in lighting, especially in spectacular and stage-lighting.

It appears to be further established that when civilized man chooses color for color's sake alone he not only prefers the pure colors but among these he prefers those near the ends of the spectrum, such as red and blue. Red is favored by women, with blue a close second, but the reverse is true for men. It is also thoroughly established that red, orange, and yellow exert an exciting influence; yellow-green, green, and blue-green, a tranquilizing influence, and blue and violet a subduing influence upon mankind. All these results were obtained with colors divorced from surroundings and actual usage. In the use of light and color the laws of harmony and esthetics must be obeyed, but the sensibility of the lighting artist is a satisfactory guide. Harmonies are of many varieties, but they may be generally grouped into two classes, those of analogy and those of contrast. The former includes colors closely associated in hue and the latter includes complementary colors. No rules in simplified form can be presented for the production of harmonies in light and color. These simplifications are made only by those who have not looked deeply enough into the subject through observation and experiment to see its complexity.

The expressiveness of light finds applications throughout the vast field of lighting, but the stage offers great opportunities which have been barely drawn upon. When one has awakened to the vast possibilities of light, shade, and color as a means of expression it is difficult to suppress a critical attitude toward the crudity of lighting effects on the present stage, the lack of knowledge pertaining to the latent possibilities of light, and the superficial use of this potential medium. The crude realism and the almost total absence of deep insight into the attributes of light and color are the chief defects of stage-lighting to-day. One turns hopefully toward the gallant though small band of stage artists who are striving to realize a harmony of lighting, setting, and drama in the so-called modern theater. Unappreciated by a public which flocks to the melodramatic movie, whose scenarios produced upon the legitimate stage would be jeered by the same public, the modern stage artist is striving to utilize the potentiality of light. But even among these there are impostors who have never achieved anything worth while and have not the perseverance to learn to extract some of the power of light and to apply it effectively. Lighting suffers in the hands of the artist owing to the absence of scientific knowledge and it is misused by the engineer who does not possess an esthetic sensibility. Science and art must be linked in lighting.

The worthy efforts of stage artists in some of the modern theaters lack the support of the producers, who cater to the taste of the public which pays the admission fees. Apparently the modern theater must first pass through a period in which financial support must be obtained from those who are able to give it, just as the symphony orchestra has been supported for the sake of art. Certainly the time is at hand for philanthropy to come to the aid of worthy and capable stage artists who hope to rescue theatrical production from the mire of commercialism.

Soldiers' and Sailors' Monument