Living pictures; their history, photoproduction and practical working. With a digest of British patents and annotated bibliography (1899)

44 LIVING PICTURES. whether the permanently illuminated object is only permitted to throw its image on the plate for an equally limited space of time. But, in its early days, the science of Photography did not provide its devotees with the means of securing an image in a sufficiently short time—a rapid exposure might be made, but no surface of adequate sensibility was available ; so, though Photography was employed very early in the production of images for the Phenakistoscope, yet the only advantage secured was an accuracy of outline not to be obtained by hand. Plateau, in 1849, suggested^the employment of photo- graphy for obtaining a series of pictures (preferably stereoscopic) which should be absolutely correct in out- line, but he only foresaw a series of prepared models as the originals of his views; the length of exposure necessary excluded other ideas. This accuracy of out- line, in some instances, was all that was required. When Desvignes, in i860, obtained a series of views destined to show a steam-engine in action the process was simple and the result certain. Each element of the engine necessarily followed a predetermined and invariable path, and consequently it was only requisite to place the engine in successive positions of one fly-wheel revolution in order to obtain a series of photographs which, when combined in the Zoetrope, undoubtedly gave an accurate representation of the engine's usual motion. Still, it was in no sense a reconstruction of a previously existing action of the machine. The separate views were not obtained during the engine's motion, and their accuracy was due entirely to the certainty with which the object could be placed in a series of positions known on mechanical grounds to be those assumed by it when in action. This certainty could not be secured when living creatures were the subjects, and they could only be