A 19th Century ebony octant, the ivory maker's plaque stamped Owen, Owens 6 South Castle St., Liverpool the frame with ivory scale, pin-hole sight, three shades, mirrors, the index arm with vernier tangent screw and clamp -- 9¾in (24.7 cm) radius, with trade label for Cousens & Son 20, Wind Street Swansea, in shaped case

細節

A 19th Century ebony octant, the ivory maker's plaque stamped Owen, Owens 6 South Castle St., Liverpool the frame with ivory scale, pin-hole sight, three shades, mirrors, the index arm with vernier tangent screw and clamp -- 9¾in (24.7 cm) radius, with trade label for Cousens & Son 20, Wind Street Swansea, in shaped case
See illustration and trade label