Finderscope

This is a finder telescope (or finderscope) for a larger telescope. This was the finder telescope for James Ramage's 25ft Herschelian reflector.

Ramage's telescope had been mounted in the front courtyard of the ROG in 1826 and could, unlike most of the telescopes used at the Observatory be managed by only one person. It was however little used and was dismantled in 1836 (after Ramage died in 1835) and returned to the executors of his will.

The finderscope is made up of a brass tube, painted black and a brass mounting also painted black.

Telescope: The objective lens is 500mm (2 inches), the tube is 310mm in length. It has a push pull focuser. There is an eyepiece in the tube and no others. There are are cross hairs in the eyepiece in the field of view making a target.

Stand/ mounting: The tube has a bracket to fit it onto the side of a telescope but no holes to attach it to the telescope. There are two supports to hold the tube, one at each end of an oblong metal plate. The supports have large round holes at the top to hold the telescope. Each support has four screws which keep the tube in place and allow the position of the tube to be adjusted.

Object Details

ID: AST0921
Collection: Astronomical and navigational instruments
Type: Telescope
Display location: Not on display
Creator: Unknown
Date made: circa 1826
People: Royal Greenwich Observatory; Woolley, Richard van der Riet
Credit: National Maritime Museum, Greenwich, London. Presented to the Astronomer Royal in 1967.
Measurements: Overall: 120 mm x 310 mm x 70 mm