Edison, His Life and Inventions [205]
what he has really done as the world's new Purveyor of Pleasure. And yet it all depends on the toilful conquest of a subtle and intricate art. The story of the invention of the phonograph has been told. That of the evolution of motion pictures follows. It is all one piece of sober, careful analysis, and stubborn, successful attack on the problem.
The possibility of making a record of animate movement, and subsequently reproducing it, was predicted long before the actual accomplishment. This, as we have seen, was also the case with the phonograph, the telephone, and the electric light. As to the phonograph, the prediction went only so far as the RESULT; the apparent intricacy of the problem being so great that the MEANS for accomplishing the desired end were seemingly beyond the grasp of the imagination or the mastery of invention.
With the electric light and the telephone the prediction included not only the result to be accomplished, but, in a rough and general way, the mechanism itself; that is to say, long before a single sound was intelligibly transmitted it was recognized that such a thing might be done by causing a diaphragm, vibrated by original sounds, to communicate its movements to a distant diaphragm by a suitably controlled electric current. In the case of the electric light, the heating of a conductor to incandescence in a highly rarefied atmosphere was suggested as a scheme of illumination long before its actual accomplishment, and in fact before the production of a suitable generator for delivering electric current in a satisfactory and economical manner.
It is a curious fact that while the modern art of motion pictures depends essentially on the development of instantaneous photography, the suggestion of the possibility of securing a reproduction of animate motion, as well as, in a general way, of the mechanism for accomplishing the result, was made many years before the instantaneous photograph became possible. While the first motion picture was not actually produced until the summer of 1889, its real birth was almost a century earlier, when Plateau, in France, constructed an optical toy, to which the impressive name of "Phenakistoscope" was applied, for producing an illusion of motion. This toy in turn was the forerunner of the Zoetrope, or so-called "Wheel of Life," which was introduced into this country about the year 1845. These devices were essentially toys, depending for their successful operation (as is the case with motion pictures) upon a physiological phenomenon known as persistence of vision. If, for instance, a bright light is moved rapidly in front of the eye in a dark room, it appears not as an illuminated spark, but as a line of fire; a so-called shooting star, or a flash of lightning produces the same effect. This result is purely physiological, and is due to the fact that the retina of the eye may be considered as practically a sensitized plate of relatively slow speed, and an image impressed upon it remains, before being effaced, for a period of from one-tenth to one-seventh of a second, varying according to the idiosyncrasies of the individual and the intensity of the light. When, therefore, it is said that we should only believe things we actually see, we ought to remember that in almost every instance we never see things as they are.
Bearing in mind the fact that when an image is impressed on the human retina it persists for an appreciable period, varying as stated, with the individual, and depending also upon the intensity of the illumination, it will be seen that, if a number of pictures or photographs are successively presented to the eye, they will appear as a single, continuous photo- graph, provided the periods between them are short enough to prevent one of the photographs from being effaced before its successor is presented. If, for instance, a series of identical portraits were rapidly presented to the eye, a single picture would apparently be viewed, or if we presented to the eye the series of photographs of a moving object, each one representing a minute successive
The possibility of making a record of animate movement, and subsequently reproducing it, was predicted long before the actual accomplishment. This, as we have seen, was also the case with the phonograph, the telephone, and the electric light. As to the phonograph, the prediction went only so far as the RESULT; the apparent intricacy of the problem being so great that the MEANS for accomplishing the desired end were seemingly beyond the grasp of the imagination or the mastery of invention.
With the electric light and the telephone the prediction included not only the result to be accomplished, but, in a rough and general way, the mechanism itself; that is to say, long before a single sound was intelligibly transmitted it was recognized that such a thing might be done by causing a diaphragm, vibrated by original sounds, to communicate its movements to a distant diaphragm by a suitably controlled electric current. In the case of the electric light, the heating of a conductor to incandescence in a highly rarefied atmosphere was suggested as a scheme of illumination long before its actual accomplishment, and in fact before the production of a suitable generator for delivering electric current in a satisfactory and economical manner.
It is a curious fact that while the modern art of motion pictures depends essentially on the development of instantaneous photography, the suggestion of the possibility of securing a reproduction of animate motion, as well as, in a general way, of the mechanism for accomplishing the result, was made many years before the instantaneous photograph became possible. While the first motion picture was not actually produced until the summer of 1889, its real birth was almost a century earlier, when Plateau, in France, constructed an optical toy, to which the impressive name of "Phenakistoscope" was applied, for producing an illusion of motion. This toy in turn was the forerunner of the Zoetrope, or so-called "Wheel of Life," which was introduced into this country about the year 1845. These devices were essentially toys, depending for their successful operation (as is the case with motion pictures) upon a physiological phenomenon known as persistence of vision. If, for instance, a bright light is moved rapidly in front of the eye in a dark room, it appears not as an illuminated spark, but as a line of fire; a so-called shooting star, or a flash of lightning produces the same effect. This result is purely physiological, and is due to the fact that the retina of the eye may be considered as practically a sensitized plate of relatively slow speed, and an image impressed upon it remains, before being effaced, for a period of from one-tenth to one-seventh of a second, varying according to the idiosyncrasies of the individual and the intensity of the light. When, therefore, it is said that we should only believe things we actually see, we ought to remember that in almost every instance we never see things as they are.
Bearing in mind the fact that when an image is impressed on the human retina it persists for an appreciable period, varying as stated, with the individual, and depending also upon the intensity of the illumination, it will be seen that, if a number of pictures or photographs are successively presented to the eye, they will appear as a single, continuous photo- graph, provided the periods between them are short enough to prevent one of the photographs from being effaced before its successor is presented. If, for instance, a series of identical portraits were rapidly presented to the eye, a single picture would apparently be viewed, or if we presented to the eye the series of photographs of a moving object, each one representing a minute successive