fluorescent screen for Hilger spectrograph

Small, square wood fluorescent screen (green) for use with an Adam Hilger spectrographic camera. According to the 1928 trade catalogue, in which this E68 model is found, this screen was used to replace the dark slide for visual observations of the ultraviolet spectrum. A scale of wavelengths is provided and a small patch of diffusing medium on which the position of the various parts of the visible spectrum can be seen as a prolongation of the fluorescent ultraviolet spectrum. Original price: 5 pounds (May 1932)