Pocket telescope

This brass telescope has a single draw tube and a tripod stand that fits inside when the telescope is not in use. The eyepiece has a thumbwheel, which allows the magnification of the telescope to be changed by selecting one of four numbered lenses. Numbered stop lines engraved on the draw tube correspond to each of the lenses and indicate the appropriate working length of the telescope. Inside the eyepiece assembly there is a smoked-glass filter that can be moved in front of the eyepiece lens in very bright conditions.

The maker's name, 'Dollond / London', is inscribed on the draw tube. The company was one of the leading makers of optical instruments in London from the 18th century onwards.

Object Details

ID: NAV1516
Collection: Astronomical and navigational instruments
Type: Pocket telescope
Display location: Not on display
Creator: Dollond & Aitchison
Date made: circa 1770
Credit: National Maritime Museum, Greenwich, London, Caird Collection
Measurements: Overall: 117 mm; Diameter: 42 mm
Parts: Pocket telescope