Box type pocket sextant.

Pocket box sextant made by Charles Augustus Schmalcalder

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Pocket box sextant made by Charles Augustus Schmalcalder
Science Museum Group
© The Board of Trustees of the Science Museum

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)