Pocket box sextant, unsigned, English, 1845-1855. Consists of two circular lacquered brass plates with lid that acts as a handle when used. Fitted with Inlaid silver 124° scale (-5° to 145°) with 30' divisions and a silver vernier (1' div.). The index arm is rotated by a milled knob on the upper plate with two filter shades (red & green) operated by lever. The index glass is fixed with adjustment for the horizon glass. Fitted with magnifier (single lens) on hinged 35 mm swivel arm and choice of a large and a small pinhole sight but telescope missing.
Details
- Category:
- Surveying
- Collection:
- Sir Henry Wellcome's Museum Collection
- Object Number:
- 1979-272
- Materials:
- glass and brass (copper, zinc alloy)
- type:
- box sextant
- credit:
- On loan from the Wellcome Trust