细节
A late 18th-Century French brass graphometer,
signed on the alidade Ecole de Chalons Carrier-Feral, with engraved protractor scale divided 0°-180°/180°-0°, the frame with two fixed sights, on ball and socket joint with staff mounting and mahogany stand -- 10½in. (26.7cm.) high, with fitted case -- 33in. (33cm.) wide
See Illustration
signed on the alidade Ecole de Chalons Carrier-Feral, with engraved protractor scale divided 0°-180°/180°-0°, the frame with two fixed sights, on ball and socket joint with staff mounting and mahogany stand -- 10½in. (26.7cm.) high, with fitted case -- 33in. (33cm.) wide
See Illustration