A rare 19th Century German brass sextant, signed on the frame Pistor & Schiek Berlin No 251, with six shades, mirrors, silvered scale engraved 0° - 150°, and adjustable telescope mounting socket, the index arm -- 7¾in (7.2cm) radius with vernier and magnifier, tangent screw adjustment and clamp, with lignum-vitae handle, three telescopes and eye-piece shade in keystone shaped mahogany case