Two Ros 'Wheel of Life' magic lantern slides, British, 1870s.
© National Media Museum / Science & Society Picture Library
These slides were used in a projection version of the Phenakistoscope, patented by Thomas Ros in 1869 and 1871. The Phenakistoscope was a simple animation device consisting of a flat disc painted black on one side, with slots cut into the outer edge. On the unpainted side between the slots a series of sketches were drawn with slight changes from one to the next. When the disc was spun and the viewer looked at its reflection through the apertures on the disc's circumference, the drawings appeared to move. In Ros' projection version, a handle turned both a transparent 13-picture disc and a 13-slot counter-rotating shutter disc to give an illusion of movement on a screen, when projected by a magic lantern.