Pair of small Gregorian reflecting telescopes, mid 18th-mid 19th century.
© Science Museum / Science & Society Picture Library
A pair of telescopes with speculum (metal) mirrors mounted on tripod stands. Both use the Gregorian optical configuration to produce upright images. The telescope covered in shagreen was made by the London instrument maker George Adams the Elder (1709-1772) between 1734-50. The claw-foot tripod stand allows the telescope to be used with a table, while a tapering screw thread is exposed if the pillar is detached from the tripod, allowing it to be used outdoors by screwing the pillar stand into the trunk of a tree. The telescope with a short bras tube was made by John Cuthbert of London in 1852. The tripod stand with levelling screws allows the telescope to be used on a table, while focusing is achieved by moving the tiny mirror at the top of the tube.