Astronomical watch by George Margetts, London, no. 3043, c. 1780

This highly complex, top-quality watch shows much detailed astronomical information, including the phase of the Moon and the position of Sun in the zodiac. The paired curved gold bars across the dial represent the horizon and show, above it, the constellations you can see on any night. An inner ring gives the tide times at ports around the coast.

Source: Ricardo de Varennes