'Pepper's ghost', 1863.
© Science Museum / Science & Society Picture Library
Plate taken from the 'Illustrated London News'. 'Profesor' Pepper (1821-1900), director of the Royal Polytechnic Institution from the early 1850s onwards is best remembered for the popular illusion 'Pepper's ghost'. In fact, the optical illusion was first developed by Henry Dircks, who first demonstrated its execution to the British Asociation in 1858. Dircks entered into a partnership with Pepper, but they fell out over the isue of credit for the discovery, Dirck's criticising Pepper in his 1863 book, 'The Ghost'. The 'ghost' was produced by a vertical screen of plate glas set diagonally acros the stage, the effect being aided by screens and appropriate illumination.