Prism stand with height adjusment signed LeRebours a Paris

Prism stand with height adjustment signed  ‘LeRebours A Paris’. The prisms can be rotated around two mutually perpendicular, horizontal axes.A prism is a transparent optical element with flat, polished surfaces that refract light. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides. A prism can be used to break light up into its constituent spectral colors (the colors of the rainbow). Prisms can also be used to reflect light, or to split light into components with different polarizations.Measuremens: 46 x 8,5 x 11 cm.Lerebours (1789 – 1845)