A BRASS UNIVERSAL RING DIAL, signed J. Jackson Fecit, English, early 18th century, engraved with the degree scale for North and South latitude and with altitude scale on the reverse, pivoted 24-hour roman chapter ring, the support for the pinhole sight engraved with calendar, degree and Zodiac scales--3in. (7.6cm.) diam.

细节

A BRASS UNIVERSAL RING DIAL, signed J. Jackson Fecit, English, early 18th century, engraved with the degree scale for North and South latitude and with altitude scale on the reverse, pivoted 24-hour roman chapter ring, the support for the pinhole sight engraved with calendar, degree and Zodiac scales--3in. (7.6cm.) diam.