"Winter landscape. Hand-coloured magic lantern slide, 19th century. The kaleidoscopic element revolves around the central snow scene. This is achieved by having two circular glasses, one fixed and painted with the background and the other which rotates. The moving glass is fixed in a toothed brass rim and turned by a pinion wheel attached to a handle at the side of the slide."
© National Museum of Science & Media / Science & Society Picture Library