Portable reflecting telescope, c 1767

Portable reflecting telescope, c 1767. This reflecting telescope can be used with any one of three different optical configurations (Gregorian, Cassegrainian or Newtonian) by replacing the smaller mirror. It was made by James Short (1710-1768), then the foremost optical instrument maker in London, and has a nine inch (229 mm) speculum metal mirror. The telescope is mounted on Short's so-called 'universal'; a portable equatorial stand with a wooden fork holding the tube and an adjustable polar axis. The whole wooden framework moves on wheels and has carrying rods like a sedan chair. Selling for several hundreds pounds, a considerable sum at the time, this extravagent telescope would probably only have been purchased by wealthy amateurs. Photographie. ©SSPL/Science Museum