Photobioscope

In 1865 Gaëtan Bonelli registered a patent for ‘the application of microscopic photography to the effects of animated images, called Biophotography’. The apparatus’s principle was based on that of the phenakistoscope. It was not until 1867, however, that Henry Cook, in his and Bonelli’s name, demonstrated an optical device for viewing of stereoscopic pictures in motion to the Société Française de Photographie. His ‘Photobioscope’ combined the effects of the phenakistoscope and photography. A glass disc with two series of stereoscopic photographs of the same subject, taken successively from different angles, is placed in the instrument and animated with a circular motion driven by the crank. Looking through the eyepieces the viewer sees the subject moving in relief. Although conceived as an entertainment, this device could also be used to measure the persistence of vision.