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

C6 LIVING PICTURES. a revolution. When this occurred the roller made one turn and drew down sufficient film to remove the exposed picture and substitute the next portion of the film. While this was stationary and the cam making its next revolution, the winding-up bobbin was storing away the piece of film just pulled down, while the feeding-spool was reeling-off just sufficient to supply the next sudden revolution of the spring roller, the spring of which was at the same time being wound-up. A special shutter was also shown, but it was of com- paratively little importance when com.pared with the arrangement for intermittent film-feeding described above. Greene was also working about this time, apparently in conjunction with Rudge, on a machine designed to project successive pictures without interrupting the light. The images were placed alternately on the edges of two discs which revolved side by side in front of a single large condenser. The light and condenser could be moved slightly out of the central line so as to illuminate, say, the left-hand picture, and were then shifted so as to light up the next design situated on the right-hand disc. While this was being shown the left-hand disc turned one stage in order to bring the third picture in position. Separate projection lenses were used, one facing each disc. The extent of move- ment required by the condenser in order to illuminate the images alternately was very small, and furthermore the light was not suddenly cut-off, but died away gradually, thus reducing the flicker. An experimental machine on these principles was shown before the Bath Photographic Society, but there appears to be no record as to any exhibition of the perfected instrument. As before stated, the honour of prior publicity undoubtedly rests with Messrs. Greene and Evans, but others were working at the same problem, and in