A late 18th-Century lacquered brass and ebony octant signed on the brass index arm Devot fils, an Havre, with double 'pin-hole' sight, three shades, mirrors, the index arm with framed vernier scale, tangent screw adjustment with clamp, inset ivory arc divided 0°o-100°o on three brass pillar feet, in shaped wooden case with French and American trade labels - 13in. (33cm.) wide.