RESIDENCE illumination is comparatively a new art. Before the invention of the incandescent electric lamp and of the gas mantle, it was difficult to get enough light; now the problem is to distribute the light properly and shade and tone it so as to eliminate glare. To residence illumination comparatively little attention has been devoted by illuminating engineers. Their efforts are concentrated on commercial and public buildings, where contracts are larger and more lucrative. And when they attempt to apply to the lighting of houses the experience gained in the lighting of hotels and stores, they discover that conditions are diametrically dissimilar. Even in commercial lighting, engineers are apt to rely too much on the photometer and on algebraic formulae, trusting them rather than the less complicated and more direct conclusions of the human eye and common sense. In other words, they do not appear to realize that while the photometer is useful in figuring cost and quantity, the final test of illumination, public or private, under scientific direction, is its effect on the vision.

It is absolutely necessary to approach the lighting of houses from the decorative point of view. The location of the outlets and the number of lights per outlet depend not only on the size and shape of the room, but also on the color and pattern and texture of walls and furniture. Important also is the question of style. If an interior is Colonial, or Georgian, or French, or Mission, the lighting fixtures should conform, in finish as well as in shape and ornament. Different periods also have their preferences as regards material - wood and compo fixtures associating themselves with Gothic and Renaissance, crystal glass beads and balls and prisms with the Louises, the Queen Anne and the Georgian periods, dull brass with the Colonial, hammered old brass and hammered old iron with Mission, etc.

The best lighted houses are those whose illumination has been planned and whose lighting fixtures have been selected by the architect or decorator, working in close understanding with the manufacturer. Here the architect has a distinct initial advantage - not always appreciated - the fact that the owner's confidence is his from the very beginning - from the time of the adoption of the plans - and that he is in a position, where the use of electricity is concerned, to impress upon the owner the desirability of selecting the lighting fixtures before the wiring is done. The wiring is of fundamental importance. Unless the outlets are properly placed, with sufficient current for each, the skill of the wisest decorator and of the most competent engineer will fail to accomplish good lighting. Re-wiring is so expensive and often so difficult - involving the mutilation of finished walls and floors - that owners cannot often be persuaded to authorize it. The wiring of many houses is too often left to the electrician, who seldom knows anything about the art of effective and economical illumination and whose interest it is, usually, to complete his contract with as little cost to himself as possible. Either he under-wires the house and makes it impossible ever to light it well, or he overwires the house in such a way as to secure the minimum of illumination from the maximum of current.

Important in wiring for electric lighting is the question of control. Fixtures that are out of reach, and fixtures and brackets with candle lights and miniature bulbs, should have switch control. The sarko switches, with key often used in the backplate of candle brackets and others too small for regular sockets, are not particularly trustworthy or durable, especially when overloaded, as they often are. Despite the initial cost, it will pay in the long run to have all ceiling fixtures of the average house controlled by switches. In the more expensive houses the brackets also will all be on switch, and there will be such useful refinements as burglar lights and master switches, and switches to light the hall above or the hall below, etc.

In preparing a general scheme of illumination for a house, the problem should be approached room by room and floor by floor, the main rooms of the first floor taken into consideration first. Starting, for instance, with the dining-room, 14 x 17 feet, with ceiling ten feet from the floor, this means 238 square feet of floor space, which divided by fifty, equals a trifle under five as the number of 15-candle-power lights necessary, where ceiling and walls are not too dark. At this point I should explain that I have found fifty to be a convenient divisor for use in determining the proper number of lights to a room of given size, with ceiling 9 feet 6 inches, which is the average height for ceilings through the United States, and for which many manufacturers plan their ceiling fixtures, giving them an overall drop of three feet unless otherwise ordered. This brings the bottom of the fixture 6 feet 6 inches from the floor, which is right for most drop fixtures with lights up. But in very large, higher rooms fixtures should hang higher than this, and in some low rooms perhaps three inches lower. Of course, the higher a room is the more light it takes to illuminate it - something like 10 Per cent. for every additional foot over 9 feet 6 inches - while rooms as low as 8 feet 6 inches, with light ceiling and walls, need considerably less.

To return to our dining-rooms that require five lights. For a ceiling fixture we can choose between a hanging dome, that should drop to a height of 4 feet 6 inches above the floor, a shower, a stem fixture, or a ceiling plate, all with lights pointing down. Once leaded domes were the fashion. The dining-room without a dome was as much out of it as the living-room without a dado was twenty years before this time. To-day, in many parts of the country, the shower is the sine qua non of the multitude. In these localities, the dining-room without a shower is considered as barren as the Desert of Sahara. It makes not much difference what kind of a shower, or whether it gives the right kind of light in the right place; the great thing is to have a shower, like other people. The reason for having the dining-room fixture bulbs and shades point down is to light the table much while lighting the walls and ceiling little. Only when the room is used also as a living-room, or for general entertainment, is much general illumination necessary.