A fluorescent screen seen with an illuminated scale shows the wavelength(s) of entering light. A Cylindrical Quartz Lens is provided to concentrate on the slit light from weak sources. The scale is illuminated by regular white light through a window. Ultra Violet Spectroscope. A black finished device with adjustable aperture in a storage box with eyepiece shield and clamping screw. scientific instrument, balance, spectoscope, ultra violet spectroscope, prism