The objections to the open blaze for illumination are that oxygen is consumed from the air, carbon dioxide and other impurities are given off, the light is not constant, since there is a tendency to flicker and especially so in a draft, it requires more attention, is unhandy to operate and does not give the proper amount of illumination. Most of these objections are overcome in the electric light.
The source of light must be so placed that it will not strike the eyes directly. Care must be taken that there are no surfaces reflecting light directly into the eyes. The lighting system must provide illumination of sufficient intensity, yet without a glare which produces eye strain. While our modern methods of artificially producing light are a great boon to civilization, they may also be a great detriment to health to say nothing of the discomfort that is caused by improper methods of lighting our homes, schools, and workshops.
Psychological Effect of Light
It is not out of order at this time to mention the effect of light upon emotions of the human family. Proper illumination is commensurate with the particular functions carried on within the place illuminated. Note the soft light effects of the cathedral and the influence it has on the people who visit the place. Enter a church building with its “dim religious light” and note the calming effect which it has on the assembly Of worshippers. To be sure they have gathered in the place for worship and are in that state of mind which would be expected of those in a revered mood, yet there is no question as to the influence of the surroundings and especially of the lighting. It would be quite out of keeping to have the cathedral as brilliantly lighted as the “Great White Way.” The architecture, the furnishings and the lighting all have a certain influence upon the minds of the individuals.
As the dim, soft light has a quieting influence so the bright, dazzling light has a stimulating effect. This is observed in the lighting of amusement places where the predominating feature of the entertainment is hilarity. The pulse may be made to beat faster, the thoughts turned from the serious things of life to the less serious, and the mind made to desire the activities of the pleasurable things of worldly enjoyment by the peculiar environment and the intensity of the illumination. Or the mind may be soothed into the tranquil moods and the entire being made to surge with emotion, while the mind is directed from the more frivolous subjects to the deepest thoughts of the philosopher with a proper arranging of the surroundings and a soothing and delicate lighting over all. While these things do not bear directly upon the subject of hygiene in the more commonly accepted way, yet they do have a certain bearing upon health and the physiological functions of the body, especially from the standpoint of environmental influence upon the body and its adaptation through the action of Innate Intelligence.
Systems of Lighting
Direct lighting is secured by fixtures which throw the light downward into the room from which the eyes are protected by properly adjusted shades. Indirect lighting is from bowl-like fixtures in which electric lights are placed and the light rays are reflected upward toward the ceiling with no light penetrating the bowl. Semi-indirect is accomplished by using a bowl which will permit some of the light rays to penetrate.
The best results are obtained by a combination of the direct and indirect methods of lighting and in some cases by a semi-indirect way. It has been observed that the direct rays of light should not fall squarely into the eyes. It is also quite essential that in some cases there should be direct rays on the work or object under observation. To accomplish this and at the same time to keep the light out of the eyes there must be a judicial use of shades and other means of softening the light.
There are some objections to the indirect method in that all the light is thrown on the ceiling. This gives a very soft light in the room, but is not sufficiently bright and faces lose their expression; there is insufficient modeling of objects, and the interior will be almost devoid of character. This form of lighting, therefore, is undesirable for home and offices, but is not objectionable for places of amusement.
There are also objections to the direct system since the strong direct light makes too harsh shadows and a light glare which is very objectionable. By properly diffusing this direct light and adding sufficient upward light we get a much more effective and pleasing illumination.