An 18th Century brass theodolite signed HEATH AND WING LONDON, with inverting telescope and dust slide, attached to vertical segmental arc by framed vernier scale and declination and elevation plate, with central engraved locking screw, the horizontal circle with three vernier scales, circular compass box, internal bubble level, decorated compass rose, central lacquered brass boss, with faceted semi-precious stone, blued steel needle, inner compass dial divided 0-80, interposed by direction pointers, the upper circle divided 10 - 360o, on a staff mount - 9¾in.(25cm)high