|From 1830 onward, Plateau studies
the combination of two moving curves to one stationary image In his doctoral
thesis he describes this as "une espèce toute nouvelle d'anamorphoses".
In 1836 he uses the name "anorthoscope" for the first time in the "Notice
sur l'anorthoscope" in which Plateau presents his new instrument to the
members of the Academy. The instrument (in brass) contains two wheels, different
in diameter, on one axis, and driven by gears. The wheels are interchangeable,
so that it is possible to have different relative speeds.
Collection J.Plateau, Ghent
Anorthoscopic discs can be made in two versions: a drawing on a white
background, or a drawing on a black background. The drawings on white
background must revolve behind a (revolving) slit in a black disc. The
normal figure then is a black drawing on a light background. To view the
drawings on a black background, a luminous slit must revolve behind the
(revolving) disc with translucent drawing. The normal image then is white
on a black background. The discs for use in transparency are made in different
densities (oil lamps are very weak light sources!). The discs are made
translucent by impregnating them on the back with oil and then applying
a layer of varnish on both sides. This is a tedious process, and not really
suited for mass production. Hand-coloured discs are also made.