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Date: |
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Description: | ?I [foul anchor] R?
The sextant has a mahogany frame and limb with a brass index arm, fittings, and a brass stop for the index arm. It has an inlaid plate in the crossbar, which is missing. The double-ended tangent screw is located on the front of the index arm and the clamping screw, which is a modern replacement, is on the back. The sextant has three index shades, one green and two red, and no horizon shades. Index-glass adjustment is made by a screw and on the horizon glass, with its glass broken, by a lever, wing nut and a clamping screw. Attached to the sextant is a threaded telescope bracket with perpendicular adjustment by a rising-piece and a milled knob. The telescope is 74 mm in length with an erect image, and is in a wooden barrel. The sextant has no box.
The instrument has an inlaid ivory scale from -2� to 129� by 20 arcminutes, measuring to 119�. The sextant has an ivory vernier measuring to 1 arcminute, with zero at the right.
The scale mark indicates that the instrument was divided on Ramsden?s engine.
Inscription.
caption: Sextant - Front
caption: Sextant - Back
caption: unavailable | Publisher: | "http://collections.rmg.co.uk/" | Rights holder: | "Royal Museums Greenwich" | Subjects: | Sextant Vernier sextants | Source: | Royal Museums Greenwich | Identifier: | http://collections.rmg.co.uk/collections... | Go to resource |
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