Good but unsigned boxwood quadrant, marked new style and undated but most likely 1750s. Some staining but overall condition good. latitude 51.5 degrees.
Ask the Dealer
Fletcher Wallis sells objects and books relating to the history of science, medicine and technology from his unit at Admiral Vernon Arcade Portobello Road. He publishes books through Vernier Press, including Antique Medicine Chests, and Corkscrew Patents from 1795. He has been dealing for thirty five years.