Pocket telescope

This achromatic telescope has a tortoiseshell barrel, a single draw tube and silvered brass fittings. Its original rayskin-covered case also survives. The eyepiece has a thumbwheel, allowing the observer to select one of four numbered lenses of different magnifying powers. Four numbered stop lines on the draw tube indicate the optimum length for viewing with each of the eyepiece lenses.

The maker's name is inscribed on the draw tube as ‘NAIRNE & BLUNT’, while inscriptions on the screw-on eyepiece cap name two previous owners: 'John Palmer Junr JAMAICA. 1774' and 'Charles Parrott Aust 1845'. The earlier date of 1774 indicates when the telescope was made.

Object Details

ID: NAV1588
Collection: Astronomical and navigational instruments
Type: Pocket telescope
Display location: Not on display
Creator: Nairne & Blunt
Date made: 1774
People: Palmer, John; Parrott, Charles
Credit: National Maritime Museum, Greenwich, London
Measurements: Length: 109 mm (closed); 160 mm (open to stop line 4); Diameter: 44 mm (barrel). Case: 116 x 55 mm
Parts: Pocket telescope