A Georg Zorn gilt brass astronomical compendium,, German, circa 1600

A Georg Zorn gilt brass astronomical compendium, German, circa 1600,
stamped with the initials G Z, the upper outer face with luni-solar conversion disc showing the age and phase of the moon, symmetrical leaf corner decoration, upper inner face with wind rose and shaped and engraved index, lower inner face with inset compass well and hinged gnomon with horizontal hour dial, compartment under compass well opening to internal face stamped with sixty cities and latitudes, lower outer face with a perpetual volvelle calendar showing the times of sunrise and set and length of day and night, 2 1/4in (5.8cm) square