AN 18TH-CENTURY SILVER AND GILT PERPETUAL CALENDAR, unsigned, the obverse decorated with a nautical compass and table of Days of the Week with Zodiac signs, rotating over the calibrated scale for thirty one days, the reverse with apertures for Hours of Sunlight, Months and Days, length of Day and Night and time of Sunrise and Sunset and engraved with the principal points of the compass, contained in a chamois leather lined embossed leather case - 2¼in.(5.7cm)diam