The painter who uses line and color imitatively has perhaps acquired skill in depicting objects and more or less appreciation of the beautiful. But if he is to be creative and to produce a higher art he must be able to use line and color without reference to objects. He thus may aid in the development of an abstract art which is the higher art and at the same time aid in educating the public to appreciate pure color-harmonies. From these momentary expressions of light and from the experience gained, the mobile colorist would receive material aid and his productions would be viewed by a more receptive audience or rather "optience" as it may be called. The development of taste for abstract art is needed in order that the art of mobile light may develop and, incidentally, an appreciation of the abstract in art is needed in all arts.

Science has contributed much by way of clearing the decks. It has produced the light-sources and the apparatus for controlling light. It has a.n.a.lyzed the physical aspects of color-mixture and has acc.u.mulated extensive data pertaining to color-vision. It has pointed out pitfalls and during recent years has been delving further by investigating the psychology of light and color. The latter field is looked to for valuable information, but, after all, there is one way of making progress in the absence of data and that is to make attempts at the production of impressive effects of mobile light. Some of these have been made, but unfortunately they have been heralded as finished products.

Perhaps the most general mistake made is in relating sounds and colors by stressing a mere a.n.a.logy too far. Notwithstanding the vibratory nature of the propagation of sound and light, this is no reason for stressing a helpful a.n.a.logy. After all it is the psychological effect that is of importance and it is absurd to attribute any connection between light-waves and sound-waves based upon a relation of physical quant.i.ties. No s.p.a.ce will be given to such a relation because it is so absurdly superficial; however, the language of music will be borrowed with the understanding that no relation is a.s.sumed.

A few facts pertaining to vision will indicate the trend of developments necessary in the presentation of mobile light. The visual process synthesizes colors and at this point departs widely from the auditory process. The sensation of white may be due to the synthesis of all the spectral colors in the proportions in which they exist in noon sunlight or it may be due to the synthesis of proper proportions of yellow and blue, of red, green, and blue, of purple and green, and a vast array of other combinations. A mixture of red and green lights may produce an exact match for a pure yellow. Thus it is seen that the mixture of lights will cause some difficulty. For example, the components of a musical chord may be picked out one by one by the trained ear, but if two or more colored lights are mixed they are merged completely and the resultant color is generally quite different from any of the components.

In music of light, the components of color-chords must be kept separated, for if they are intermingled like those of musical chords they are indistinguishable. Therefore, the elements of harmony in mobile light must be introduced by giving the components different spatial positions.

The visual process is more sluggish than the auditory process; that is, lights must succeed each other less rapidly than musical notes if they are to be distinguished separately. The ear can follow the most rapid execution of musical pa.s.sages, but there is a tendency for colors to blend if they follow one another rapidly. This critical frequency or rate at which successive colors blend decreases with the brightness of the components. If red and green are alternated at a rate exceeding the critical frequency, a sensation of yellow will result; that is, neither component will be distinguishable and a steady yellow or a yellow of flickering brightness will be seen. The hues blend at a lower frequency than the brightness components of colors; hence there may be a blend of color which still flickers in brightness. Many weird results may be obtained by varying the rate of succession of colors. If this rate is so low that the colors do not tend to merge, they are much enriched by successive contrast. It is known that juxtaposed colors generally enrich one another and this phenomenon is known as simultaneous contrast.

Successive contrast causes a similar effect of heightened color.

An effect a.n.a.logous to dynamic contrast in music may be obtained with mobile light by varying the intensity of the light or possibly the area.

Melody may be simply obtained by mere succession of lights. Tone-quality has an a.n.a.logy in the variation of the purity of color. For example, a given spectral hue may be converted into a large family of tints by the addition of various amounts of white light. Rhythm is as easily applied to light as to music, to poetry, to pattern, or to the dance, but in mobile lights its limitations already have been suggested. However, it is bound to play an important part in the art of mobile light because rhythmic experiences are much more agreeable than those which are non-rhythmic. Rhythm abounds everywhere and nothing so stirs mankind from the lowliest savage to the highly cultivated being as rhythmic sequences.

Many psychological effects of light have been recorded from experiment and observation and affective values of light have been established in various other byways. It is possible that the degree of pleasure experienced by most persons on viewing a color-harmony or the delightful color-melody of a sunlit opal may be less than that experienced on listening to the rendition of music. However, if this were true it would offer no discouragement, because absolute values play a small part in life. Two events when directly compared apparently may differ enormously in their ability to arouse emotions, but the human organism is so adaptive that each in its proper environment may powerfully affect the emotions. For example, those who have sported in aerial antics in the heights of cloudland or have stormed the enemy's trench are still capable of enjoying a sunset or the call of a bird to its mate at dusk.

The wonderful adaptability of the inner being is the salvation of art as well as of life.

In the rendition of mobile light it is fair to give the medium every advantage. Sometimes this means to eliminate compet.i.tors and sometimes it means to remove handicaps. On the stage light has had compet.i.tors which are better understood. For example, in the drama words and action are easily understood, and regardless of the effectiveness of light it would not receive much credit for the emotive value of the production.

In the wonderful harmony of music, dance, and light in certain recent exhibitions, the dance and music overpowered the effects of lights because they speak familiar languages.

[Ill.u.s.tration: A community Christmas tree

A community song-festival

ARTIFICIAL LIGHT IN COMMUNITY AFFAIRS]

[Ill.u.s.tration: PANAMA-PACIFIC EXPOSITION

Artificial light not only reveals the beauty of decoration and architecture but enthralls mankind with its own unlimited powers]

A number of attempts have been made to utilize light as an accompaniment of music and some of them on a small scale have been sincere and creditable, but a much-heralded exhibition on a large scale a few years ago was not the product of deep thought and sincere effort. For example, colored lights thrown upon a screen having an area of perhaps twenty square feet were expected to compete with a symphony orchestra in Carnegie Hall. The music reached the most distant auditor in sufficient volume, but the lighting effect dwindled to insignificance. Without entering into certain details which condemned the exhibition in advance, the method of rendition of the light-accompaniment revealed a lack of appreciation of the problems involved on the part of those responsible.

Incidentally, it has been shown that the composer of this particular musical selection with its light accompaniment was psychologically abnormal; that is, he was affected with colored audition. It is not yet established to what extent normal persons are similarly affected by light and color. Certainly there is no similarity among the abnormal and none between the abnormal and normal.

If light is to be used as an accompaniment to music, it must be given an opportunity to supply "atmosphere." This it cannot do if confined to an insignificant spot; it must be given extensity. Furthermore, by the use of diaphanous hangings, form will be minimized and the evanescent effects surely can be charming. But finally the lighting effects must fill the field of vision just as the music "fills the field of audition"

in order to be effective. There are fundamental objections to the use of mobile light as an accompaniment to music and therefore the future of the art of mobile light must not be allowed to rest upon its success with music. If it progresses through its relation with music, so much is gained; if not, the relation may be broken for music is quite capable of standing alone.

There is a tendency on the part of some revolutionary stage artists to give to lighting an emotional part in the play, or, in other words, to utilize lighting in obtaining the proper mood for the action of the play. Color and purely pictorial effect are the dominant notes of some of them. All of these modern stage-artists are abandoning the intricately realistic setting, and, as a consequence, light is enjoying a greater opportunity. In the more common and shallow theatrical production, lighting and color effects have many times saved the day, and, although these effects are not of the deeper emotional type, they may add a spectacular beauty which brings applause where the singing is mediocre and the comedy isn't comedy. The potentiality of lighting effects for the stage has been barely drawn upon, but as the expressiveness of light is more and more utilized on the stage, the art of mobile light will be advanced just so much more. Light, color, and darkness have many emotional suggestions which are easily understood and utilized, but the blending of mobile light with the action is difficult because its language is only faintly understood.

It is futile to attempt to describe a future composition of mobile light. Certainly there is an extensive variety of possibilities. A sunset may be compressed into minutes or an opalescent sky may be a motif. Varying intensities of a single hue or of allied hues may serve as a gentle melody. Realistic effects may be introduced. The expressiveness of individual colors may be taken as a basis for constructing the various motifs. These may be woven into melody in which rhythm both in time and in intensity may be introduced. Action may be easily suggested and the number of different colors, in a broad sense, which are visible is comparable to the audible tones. Shading is as easily accomplished as in music and the development of this art need not be inhibited by a lack of mechanical devices and light-sources. The tools will be forthcoming if the conscientious artist requests them.

Whatever the future of the art of mobile light may be, it is certain that the utilization of the expressiveness of light has barely begun. It may be that light-music must pa.s.s through the "ragtime" stage of fireworks and musical-revue color-effects. If so, it is gratifying to know that it is on its way. Certainly it has already served on a higher level in some of the artistic lighting effects in which mobility has featured to some extent.

If the art does not develop rapidly it will be merely following the course of other arts. A vast amount of experimenting will be necessary and artists and public alike must learn. But if it ever does develop to the level of a fine art its only rival will be music, because the latter is the only other abstract art. Material civilization has progressed far and artificial light has been a powerful influence. May it not be true that artificial light will be responsible for the development of spiritual civilization to its highest level? If mobile light becomes a fine art, it will be man's most abstract achievement in art and it may be incomparably finer and more ethereal than music. If this is realized, artificial light in every sense may well deserve to be known as the torch of civilization.

READING REFERENCES

No attempt will be made to give a pretentious bibliography of the literature pertaining to the various aspects of artificial lighting, for there are many articles widely scattered through many journals. _The Transactions of the Illuminating Engineering Society_ afford the most fruitful source of further information; the _Illuminating Engineer_ (London), contains much of interest; and _Zeitschrift fur Beleuchtungswesen_ deals with lighting in Germany. H. R. D'Allemagne has compiled an elaborate "Historie du Luminaire" which is profusely ill.u.s.trated, and L. von Benesch in his "Beleuchtungswesen" has presented many elaborate charts. In both these volumes lighting devices and fixtures from the early primitive ones to those of the nineteenth century are ill.u.s.trated. A few of the latest books on lighting, in the English language, are "The Art of Illumination," by Bell; "Modern Illuminants and Illuminating Engineering," by Gaster and Dow; "Radiation, Light and Illumination," by Steinmetz; "The Lighting Art,"

by Luckiesh; "Illuminating Engineering Practice," consisting of a course of lectures presented by various experts under the joint auspices of the University of Pennsylvania and the Illuminating Engineering Society; "Lectures on Illuminating Engineering," comprising a series of lectures presented under the joint auspices of Johns Hopkins University and the Illuminating Engineering Society; and "The Range of Electric Searchlight Projectors," by Rey; "The Electric Arc," by Mrs. Ayrton; "Electric Arc Lamps," by Zeidler and l.u.s.tgarten, and "The Electric Arc," by Child treat the scientific and technical aspects of the arc. G. B. Barham has furnished a book on "The Development of the Incandescent Electric Lamp."

"Color and Its Applications," and "Light and Shade and Their Applications," are two books by Luckiesh which deal with lighting from unique points of view. "The Language of Color," by Luckiesh, aims to present what is definitely known regarding the expressiveness and impressiveness of color. W. P. Gerhard has supplied a volume on "The American Practice of Gaspiping and Gas Lighting in Buildings," and Leeds and b.u.t.terfield one on "Acetylene." A recent book in French by V.

Trudelle treats "Lumiere Electrique et ses differentes Applications au Theatre." Many books treat of photometry, power-plants, etc., but these are omitted because they deal with phases of light which have not been discussed in the present volume. "Light Energy," by Cleaves, is a large volume devoted to light-therapy, germicidal action of radiant energy, etc. References to individual articles will often be found in the various indexes of publications.

THE END