Box type pocket sextant.
Pocket box sextant made by Charles Augustus Schmalcalder, 82 Strand, London, England, 1810-1826. Consists of two circular lacquered brass plates with lid that acts as a handle when used. Fitted with Inlaid silver 128° scale (-5° to 150°) 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 40 mm swivel arm and choice of a large and a small pinhole sight but telescope missing.
Details
- Category:
- Surveying
- Object Number:
- 1872-81
- Materials:
- casing, brass, blackened, shades, glass, reading lens, glass and mirrors, glass
- type:
- box sextant
- credit:
- South Kensington Museum (Circulation Department)