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THE OPEN LETTER
One summer afternoon, some years ago, I went into a front room of my home and drew down the window shades to shut out the glare and heat. The room became quite dark, but, in one of the shades, there was a small hole, through which the sunlight penetrated—casting on the white wall opposite, vivid images of all the objects in the street outside. I had before me a full-color, moving picture of the panorama of life that was passing the window.
Here was the original “camera obscura” (“dark chamber”). If one placed in the small hole in the shade a glass lens to give a sharp image, and substituted for the wall a movable screen, on which the projected objects could be focussed, one would have the essential elements of a modern camera. Through just such simple experiences as this important scientific discoveries are sometimes made.
For many years photography was largely confined to portraiture and the faithful reproduction of objects and scenes. All that was expected of a camera was to “make a picture” of a thing. Within the last forty years, however, as reproductive processes have been invented, photography has come to be one of the most useful of arts. Beginning about 1883, the quality and character of the illustrations in our magazines and books changed radically. Where, previously, there had been nothing but hand engravings of one sort or another, photo-engraving appeared, and, with that, the horizon of magazine illustration extended far beyond the reach of the liveliest imagination. Who could have foreseen, then, in the first photo-engraving processes, such possibilities as photographic printing in full colors, or moving picture films? Today, pictorial illustration depends on photography, and there is apparently little or nothing in life beyond the reach of photographic art. It discloses the internal arrangements of human anatomy; it makes a record of the affairs of the heavenly bodies; it pictures things that the human eye cannot see; it is even potent in the realm of mystery, for have we not seen photographs of ghosts(?) reproduced from spirit seances? When objects and situations in life that do not exist are wanted, the camera can, by some trick or device, create them for us. There seems to be no limit to the possibilities. Each wonder displayed in photographic reproduction gives way to some new effect more wonderful still.
Consider briefly a few of the wonders of modern photography. First and foremost, and most spectacular of all, is the moving-picture film. Then, in the world of practical things, we have the telephoto-lens—a combination of the telescope and camera—that takes pictures of objects far beyond the reach of the naked eye. This enables one to photograph the head of a gargoyle on a distant cathedral, or the fledglings in an eagle’s nest, or a mountain goat on a crag high up a mountain side. Then there is the swinging camera, by means of which a wide sweep of view can be included in one plate. A device of great practical value is photo-telegraphy, by which portraits for purposes of identification can be sent by cable and by wireless. In modern warfare the uses of the camera are many and varied. They include panoramic photography, photographing by moonlight, photographing of projectiles in the air, even photographing the noise of a gun by recording the vibrations due to the displacement of the air, photo map-making, photo surveying from the air, and the aviation gun camera. Radiography, too, must be mentioned—the X-ray and its use in surgery.