A shadow projector with no lens. Typically used a 1 kW, 2kW or 5kW lamp, and a slide about 24" square. [-]Still manufactured[/-] discontinued by Altman Cat. No. 673: Slides were often made by painting glass with transparent Colorine lamp dip. Link to most common type, the Kliegl 2048, using a 24"x24" slide. Link to the Kliegl 248, 28"x40" slide, using a 60V, 2100W lamp. The smaller, lower voltage filament produced a sharper image. Attributed to German Inventor/lighting technician Adolf Linnebach, about 1900.