Octant made by Spencer, Browning & Rust, London, England

octant

Octant, ebony frame, ivory nameplate marked "Spencer Browning & Rust London"; stamped in the scale SBR (between 45°-50°) ; scale inlaid ivory graduated -2 deg. to +100 deg. by 1 deg. subdivided to 20', flat brass index arm, ivory vernier, broken & illegible, index mirror missing, 3 removable shades, horizon glass w/adjustment & shades from index mirror, sight vane w/dbl. peep & pivoted cover, back horizon w/lever adjustment, back sight w/single peep (broken), ivory finial for pencil in hole in brace, ivory note plate on back missing, 3 brass legs on back.