细节
A brass perpetual calendar
the obverse with volvelle signed Day of the Month For Ever underneath a sun face surrounded by days and dates, the reverse with volvelle of the phases of the moon -- 1½in.(3.75cm.)diam., circa 1800
the obverse with volvelle signed Day of the Month For Ever underneath a sun face surrounded by days and dates, the reverse with volvelle of the phases of the moon -- 1½in.(3.75cm.)diam., circa 1800