Azimuth circle

Black-lacquered closed brass frame, with three heavy legs. Signed on the upper face of the frame 'H. Hughes & Son N° 6'. Bronzed limb with inlaid silver scale from 100° to -40° by 10' (mirrored image and upside down) measuring to ??°. White plastic micrometer drum graduated + or -, with a pressure clamp at the end of the index arm, and worm screw on the underside of the index arm. Silver vernier from +5 to -5...., with a spring loaded mechanism mounted at the vernier end of the index arm. Radius 7.5'' (190 mm). In a wooden box marked on the side 'N° 6298K'.