Brass double-frame sextant.

Anodized brass sextant, double-frame bridge (straight-bar) type, with polished brass limb and wooden handle, by W Harris and Company, 50 Holborn London, England, 1830-1839. Consists of inlaid 120° silver scale (-5° to 149°) with 10' divisions, gold vernier scale (20") two sets of filter shades (3 & 2, red & green) and reading magnifier on a on a worm screw. Fitted with threaded telescope bracket with collimation correction for two telescopes, 83mm (erect image).