English, c.1860, signed 'J H Steward, 406 Strand London', and 'No.8 WP Trade Mark', the instrument delicalty constructed from lacquered and oxidised brass, internal viewing mirror with geared control to top silvered scales with geared adjustment, with separate optical square, original instructions, period hand written notes, in original fitted French polished mahogany case, case width 33cm

Notes: from the instructions "Instructions for using the Macrometer as proposed by Captain W Poste, By means of a Macrometer and an optical square distances may be asertained with great accuracy, using any length of base which may be measures either by a chain, rope or by pacing it. To find the distance two men are required - one to use the Macrometer, termed the observer, and a second to use the optical square, termed the assistant."