UNIVERSAL EQUINOCTIAL RING DIAL BY BENJAMIN COLE, LONDON, CA 1750.

A 4-inch diameter universal equinoctial ring dial in brass, with suspension ring, sliding pinhole gnomon with calendrical scale to one side, and zodiacal scale to the other; upper scale engraved with latitudes for both Northern and Southern latitudes; chapter ring engraved with 24 hours (I-XII, and I-XII); equinoctial ring with declination scale to one side and degree scale to other (90°-0°-90°).

A WONDERFUL MID-18TH CENTURY UNIVERSAL EQUINOCTIAL DIAL. Also known as a "Traveler's sundial", these clever instruments would be suspended from a cord, with the suspension point on the meridian ring set to the local latitude. The center bar is then set until a ray of light passes through a small hole, and falls on the equatorial ring, indicating the time of day.