Audiovisual introductions in 1890

thumb|A drawing of a Kaiserpanorama with 25 viewing stations. The Kaiserpanorama (or Kaiser-Panorama) is a form of stereoscopic entertainment medium used chiefly in the 19th and early 20th centuries, and is considered a precursor to film. It was invented by August Fuhrmann (1844–1925), and patented by him in 1890. It consisted of a number of viewing stations from which people would peer through a pair of lenses to view a number of rotating stereoscopic glass slides. By 1910 Fuhrmann is said to have controlled exhibitions in over 250 branches across Europe, and to have held up to 100,000 slides