细节
An early 19th Century ebony octant by Bradford
signed Bradford, Maker 136 Monories, London, with pin hole sight, mirror, ivory scales, the index arm with vernier and clamp on three pillar feet (lacks shades) -- 8in. (22.2cm.) radius
signed Bradford, Maker 136 Monories, London, with pin hole sight, mirror, ivory scales, the index arm with vernier and clamp on three pillar feet (lacks shades) -- 8in. (22.2cm.) radius