LIGHTING IN THE HOME

Evening Star, Issue 23369, 12 September 1939, Page 3

LIGHTING IN THE HOME

IMPORTANCE NOT STUDIED CASUAL APPROACH DEPLORED OFTEN CAUSE OF DEFECTIVE VISION The fact that the average home is very inadequately lighted is proved, first, by actual scientific tests conducted in laboratories and in thousands of homes, and, second, by the even more convincing fact that one in five grade school children, three in five middle-aged persons, have defective . vision caused in probably a majority of cases by reading, studying, and playing under conditions which contributed to eyestrain. Obviously, therefore, we must consider lighting as more than a casual matter of putting a few lamps around the room—sufficient to dispel the dark but probably inadequate for most visual work. This haphazard and costly method should be abandoned. A proper understanding of the principles of good lighting will result in a home which is more attractive in appearance, more delightfully restful, and which will protoctj rather than jeopardise, the eyes of every member of the family. HARSH CONTRASTS. Scientists measure light in terms of foot-candles. A foot-candle is the amount of light a candle casts on a surface a foot away. Outdoors on a bright day we work or play in about 10,U00 foot-candles. If we read a book in the shade of a tree we have the benefit of 500 to 1,000 of softly diffused light. But when night comes and we take our book to an easy chair, we may expect to find in the great majority of cases not more than three foot-candles on the printed page. We find also that instead of the diffused even light which made reading so pleasant in the shade of a tree we are confronted by a glaring white page surrounded by the comparative darkness of the rest of the room. The harsh contrast between the two extremes is a further irritation to the eyes. The aim of modern residential lighting, therefore, is quite specific; To provide light of the correct amount, whether for fine work, such as sewing, for reading, for card playing, or simply for normal seeing; to eliminate glare from unshaded or poorly shaded bulbs; to create a soft diffused light through the room which will help banish harsh contrasts—the very common result of having pools of light at various points in an otherwise rather dark room. Attractive, restful lighting, in other words, is the objective. QUALITY AND QUANTITY. The means by which this objective is attained are neither mysterious nor involved. Resulting from'years of careful, exacting research conducted by the leading experts of the country, modern lighting is now as much a “ system ” as are heating and plumbing. The hard work of finding out the facts about light and its application has been done; nil we need do is take advantage of the opportunity to learn in a few minutes what these facts are and how they can be used in our own house. Quantity and quality are the two important factors in good lighting, and must always be considered together—quantity being the amount of light and quality the way in which light is distributed. We want plenty of light on the printed page, but we don’t want it to be harsh and glaring. We want a soft, pleasing light in our homo, but wc want the ability to control its intensity according to the requirements of onr various activities. Our lighting experts, therefore, recommend a combination of two kinds of lighting. The first is called local, and is typified by the direct light of the reading lamp or desk lamp; the second, called general, is the illumination throughout the room afforded by light reflected from walls or celling or from some special reflector which serves the same purpose. In other words, our primary source of light for reading, studying, sewing, etc., comes directly from the light in exactly the required amount, this amount being controlled by the number and wattage of bulbs used in the lamp and the distance from the lamp to our work. Our secondary illumination, which serves for ordinary seeing, conies indirectly from the light source, and is extremely important in that by its soft diffusion it eliminates harsh contrasts, heightens the decorative effectiveness of the room, and enables ns to use plenty of light in our reading lamps without the strain which we would experience if there were insufficient general illumination. EYE COMFORT. This ratio between local and general lighting is important. When we hear a complaint that there is “ too much light ” in a room the fault usually lies not in excessive quantity, but in poor ouality—that is, poor distribution and diffusion. It lias been found that a ratio of 10 to 1 between local and general illumination is the minimum contrast for eye comfort. For example, if 20 foot-candles of light are provided hy a desk lamp there should be two or. better still, four foot-candles of light in the surrounding areas of the room.