Octant and case, Spencer, Browning & Rust, circa 1790

octant and case

Octant of Capt. George S. Perry. Ebony frame. Ivory nameplate marked "Spencer, Browning & Rust London". Ebony limb, ivory scale marked, "SBR", graduated -2 deg. to 99 deg. by 1 deg. subdivided to 20'. Flat brass index arm. Ivory vernier. Adjustable index mirror with three removable shades. Horizon glass with lever adjustment and shades from index mirror. Single peep sight vane. Back sight missing. Back horizon with lever adjustment. Two brass legs missing. Note plate on back of frame missing. Pencil hole in brace. Step box, one end missing. Circa 1790.