Modern Magic in Light (Oct, 1927)

Modern Magic in Light

“Music” Played by Colors, Statues Dance to Help Solve Problems of Illumination

By ROBERT E. MARTIN

THE marvels of light from its crude yesterdays to its present brilliance, with a glimpse of future splendors that now seem quite incredible, are shown to visitors at a unique permanent exhibition. It is a museum and a laboratory with a factory adjacent. We see what has been, is and may be in the field of illumination.

Light used to be regarded as just something to see by. Here we find it is a force, a substance, an aesthetic material. Light is not immediately audible yet it will carry words and song. We used to think that the only virtue of light was to illuminate darkness; now we find there is more light in the dark than there is in the light. People have been “sunburned” in a dark room. They have been photographed without a speck of visible light.

Would you like to see the original incandescent lamp of 1878 which Thomas A. Edison gave the world? Here it is. Near by is a sample of red whisker— human hair—which the great inventor to whom we owe all modern illumination tried to convert into a filament. We see an interesting contrast in modernity. A giant lamp the size of a pumpkin and a dwarf the size of a pea. The big fellow uses 30,000 watts, emits 100,000 candle-power or ten times the sunlight in the Sahara desert, and costs two dollars an hour to operate. The little fellow uses about one sixth of a watt, emits one tenth candlepower and costs ten cents a year. Both are shortlived freaks compared with the average lamp that gives us one thousand hours of service.

WE ARE visiting the Edison Lighting Institute of the General Electric Company. Most of the basic scientific research for the concern is carried on elsewhere. Here at Harrison, New Jersey, is the place of practical application of discoveries, a free museum and a showroom without salesmen. Still the men here do originate many things in practical application. Take Henry Schroeder, whose history of electric light has been published by the Smithsonian Institution; A. L. Powell, virtuoso of eye music and expert in paint color values; Berthold Audsley, model maker and artist; L. C. Porter, who takes night flights in Government planes to see whether an airway is rightly beaconed. Imagine flying over your own lighting layout.

There is an auditorium with a stage and all sorts of weird and instructive shows. Someone flips a tumbler switch. With a slight buzz and clatter window curtains of the divided sort close and the auditorium becomes pitch dark. The stage curtains open and close in the same manner. It is all done simply enough by an electric motor above each opening. Automatic curtains are also used to shut off rooms which surround the Institute auditorium, neatly furnished to represent the average home, including living room, dining room, bedroom, kitchen and bath. Here a dozen ways of home lighting are demonstrated. We learn that the best general method is a center bowl which throws light against a white ceiling to be reflected downward. Of course auxiliary reading lamps and special local fixtures are also needed, while wall candelabra serve an ornamental purpose. There is a display of lamp shades. One is a curled porcelain fish whose green mouth spews foamy light through a cascade of translucent beads.

VISITORS are apt to regard the automatic curtains and other devices as amusing tricks. It is difficult at times to know whether we are witnessing a scientific demonstration or merely a funny stunt. A galloping flivver that shivers over a bumpy road is one of a series of light illusions. A dancer performs with grace and vigor. She is a plaster statue and all the dancing is done by the light that frolics over her. Then there is an oil painting of a ship at sea. Suddenly the ship is replaced by a tugboat. Nothing has been changed in the picture, but a different color of light has blotted out the large craft and revealed the small one.

Eye music is played on the fluted folds of the gray stage curtain. The tones, derived from the spectrum, red to violet, glow and fade, blend and dissolve harmoniously one into another, make us sad and glad, dreamy and excited. Peaceful blue drifts into a romantic moonlight, which becomes luxurious purple, leading imperceptibly to an active yellow and then to a trumpeting martial red. The eye music is accompanied with appropriate ear music of opera or symphony orchestra.

The instrument of the new art is a color organ. It is a medium sized box with eight lever handles of rheostats to increase and diminish light. The colors are in the individually colored lamps of the footlights and overhead lights of the auditorium stage, which, unseen by the audience, cast their glows on the curtain. It is a surprise to find that the individual lamp colors are simply red, blue, green and amber. Powell improvises, making eye music according to the inspiration of the moment. His music is not written. Perhaps some day a Bach of eye music will devise a recording system and compose works that others may play on their own light organs.

Five lighting systems are shown in the auditorium—direct, enclosing globe, semi-indirect, totally indirect and totally indirect with luminous bowl. All are in bowls. If you wish to see the glare of unshaded light—a primitive method which will be abolished before long—there is an example in the industrial room—a direct glare. Click! buzz!—The same light in a frosted bulb gently diffuses illumination. Does the color of walls and ceiling make much difference in lighting? Watch!

The white panels of this room are reversed, showing their slate-colored backs. The light is the same but fifteen percent of it is wasted, absorbed by the slate color. Very dark walls steal half to three-quarters of all the light. The moral is that paint is cheaper than electricity and light wall paper will cut down the monthly bill for current.

IN various rooms are globes, two to seven feet in diameter, made of metal in flanged sections. Each has a curved hinged door besides other attachments. These globes are photometers, for measuring light. They are white inside, to reflect all the light of a lamp placed within. They are spherical in shape because light spreads equally in all directions from a central source and we want to measure the total output of a lamp. The smallest sphere of two feet diameter has at its center a tiny lamp of one candlepower intensity. This is the basic unit of light. Each inside square foot of the sphere receives an intensity of one foot-candle or an amount that is termed one lumen. There are 12.57 square feet of internal area, so the total output is 12.57 foot-candles in intensity and the same number of lumens in amount.

Since the ordinary home lamp of forty watts yields about ten lumens per watt, its total output is 400 lumens or over thirty times that of the basic candle-power lamp—probably sixty times that of the actual tallow candle used by our ancestors.

Let us look into the eyepiece of a photometer and test our skill as a judge of light values. A pink dot appears in the center of a large glow. We turn a thumb screw until we fade out the pink dot and produce a uniform brightness. Now glance at this lumen scale. We have done well for a first attempt—only four percent error. But if the eye is the judge, will not even the expert’s eye occasionally bring in a false verdict? Yes. Science has lately met and overcome this criticism. Here we have a square box the size of a large camera. It contains a mechanical eye which looks inside the photometer sphere and makes an unbiased, 100 percent correct report. Yes, it is a photo-electric cell, the marvelous device that gives us talking pictures and television.

Somebody says that while the modern lamp is sixty times better than the tallow 31 candle, it is sixty times lower in efficiency than the firefly’s lantern. Is that so? Yes, roughly. And is the difference accounted for by the loss of energy in heat in the case of the electric lamp? No, the heat loss is small compared with the loss of invisible rays emitted at both ends of the spectrum. In vacuum lamps only eight percent and in gas-filled lamps twenty-five percent of energy is dissipated as heat. Most of the power escapes in below-red and above-violet unseen rays, leaving us a small fraction of useful illumination.

White light is a mistake from the efficiency standpoint. It has a theoretical maximum of 265 lumens per watt. Yellow-green light, used by the firefly and other wise insects, is good for 620 lumens per watt. Compare with this our ordinary achievement of ten lumens—or twenty for high power lamps—per watt. The white light or so-called optical efficiency of the average lamp is six to eight percent, but compared with the insect yellow-green output it is less than two percent. We may note that gas-filled lamps, while wasting much more energy as heat than the vacuum type, surpass the latter in illumination, because the higher temperature of filament permitted by gas-filling results in a greater output of visible rays.

LET us rest our figure-laden minds with J a visit to the model room where a toy house is being furnished and painted, a knee-high locomotive stands ready to go under 200 pounds steam pressure, and the turn of a switch illuminates a multitude of thumb-size saints in the stained glass window of a miniature cathedral. The amiable toy artist is Audsley. He made that cathedral entirely with a pocket-knife. Not long ago he built a 400-pound electric locomotive in his home attic. It took some engineering to bring that model down the attic stairs.

Such toys, capable of real performance, serve a wider purpose than entertainment. They may be used for tests of principles, designs and materials. All kinds of new lighting schemes may be experimented with in a tiny cathedral or house.

Perhaps the most intriguing model reproduces an American street. There are skyscrapers fully two feet in height, shops with plate glass windows, a movie palace with winking colored lights, familiar signs of commerce. Flip! Tall street lamps glow. Flip! Shop windows light up. The moderate illumination of the average small city. But the city hall remains in gloomy dimness. Flip! Its cornices glow with screened radiance that reveals the architectural outlines and accents the stately pillars. This model demonstrates all kinds of street lighting and shop lighting with the relations between the two. What almost any city has and might have may be vividly illustrated.

We are surprised to learn that the famous White Way or theatrical section of Broadway, New York, is not the world’s best lighted street—at least not by virtue of its street lamps, which are relatively few and faint. It owes its brilliance—uneven and confused—to a multitude of commercial signs, especially those that blink and jiggle from lofty points of vantage. State Street, Chicago, is the best lighted street in America and perhaps the world from the standpoint of rationally planned, even illumination.

SOME visitors are favored with a trip through the factory where we see the whole fascinating process of lamp making from the blowing of molten glass to the inner frosting of bulbs and the coiling of tungsten filament wire. The first impression is of large quiet spaces, with a casual distribution of machines and a striking scarcity of human operators. A dozen girls and two or three men seem to be the total personnel in one department. Yet production is at full blast. This is the triumph of modern machinery which has dispensed with scores and even hundreds of human hands.

The second impression is that everything revolves. Every machine with all its parts demonstrates the first law of the cosmos, which is revolution. It rolls with stateliness on its vertical axis while a host of satellites spin and gyrate at higher speeds. It is the perfect measured dance of planets and of atoms.

We perceive gradually another motion —the reciprocal or back and forth movement. Used sparingly, it plays a vital part. Vital indeed seem those metal fingers that pick and push and squeeze and withdraw and do a hundred tricky feats.

In a basement are bins of a grayish fine sand, nitre, sacks of white lime and a few other materials for making glass. On the floor above are half a dozen furnaces, each with a capacity of 150 tons of glass. Fuel oil has superseded gas as heat source. It takes three weeks of gradually increased heat to put a furnace in operation—otherwise the sixteen-inch walls of fire clay brick would fail—and once going it is kept at a temperature around 2700 degrees Fahrenheit for a year or so. Glass is made continuously day and night, except Sunday.

IN FRONT of each furnace stands a revolving turret. Metal fingers reach into a pool of white hot glass, withdraw two incandescent viscous lumps and deposit them in a pair of moving cups in the turret. The white lumps elongate by gravity, a puff of air makes them pear shaped, then they are encased in a mold of divided halves and blown to full size. They emerge instantly as red-hot bulbs which roll away on an asbestos belt and pass the test of a coldblooded mechanical critic. The machine produces 64,000 bulbs in its twenty-four-hour day.

A lamp-making machine takes bulbs, bits of glass tube, filament, socket bases, and converts them into lamps at the rate of 2000 a day. A crew of five girls feeds such a machine.

Arabian Nights? Here is all kinds of magic more fascinating, genuine and useful.

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