Gregorian reflecting telescope, 1852

Brass Gregorian reflecting telescope of 3-inch aperture by John Cuthbert, London on altazimuth mount with claw foot stand and adjustable feet, 1852.

Dated 1852, this reflecting telescope uses the Gregorian optical configuration. First proposed by James Gregory in 1663, it produces upright images. This is a convenience for a telescope that was as likely to be used for terrestrial viewing as for looking for objects in the sky. Made by the London instrument maker, Cuthbert the telescope has a brass dumpy tube. The tripod stand with levelling screws allows the telescope to be used on a table while focussing is achieved by moving the tiny mirror at the top of the tube. With a metal mirror and brass construction it differs little from telescopes made a hundred years earlier in the eighteenth century.