Army isue folding binoculars, c 1895.
© Science Museum / Science & Society Picture Library
Folding binoculars isued to British officers serving in the Boer War (1899-1902). Made by Aitchison & Company, London, these collapsible binoculars were patented in the 1880s. Made using aluminium, they are an early example of the use of the metal in the manufacture of lightweight optical instruments. Unlike modern instruments, using prisms, these binoculars produce an upright image by employing a pair of Galilean telescopes with large convex front lenses and concave ones for the eyepieces.