Ross Wheel of Life. Maker unknown (9 1/2 x 4 1/4 x 3/4 inches), rotary pulley mechanism with counter-rotating shutter. Included are 3 brass ferrels and 3 spare discs (1 is shattered). The invention by Thomas Ross in the early 1870s was an important forerunner of the bioscope and first moving film. It developed the invention of the phenakistiscope to create the interruption of vision and trick the mind of the viewer to believe that it was a moving image. The mechanism involved rotating a circle of animated images on mica or glass and a shutter rotating in a contra direction allowing only one of the images to be exposed in quick succession. The high costs of manufacture prevented many of these slides being made.