Multiplying glass, 1840-1850.
© Science Museum / Science & Society Picture Library
A multiplying glass is a faceted lens that shows numerous reflected copies of the image being observed. In this example, a crystal glass beaker is cut in such a way that an image of a pansy painted in the bottom appears to repeat itself many times when viewed from above. Following Sir David Brewster's invention of the kaleidoscope in 1816, optical toys of this type became increasingly popular during the Victorian period.