Switch it on, set it down, and the sundial spins around on a continuous-rotation servo until the HMC5883L compass module finds the north-south orientation.

Check out Kerry Shrives’ appraisal of a French brass pocket sundial with compass, ca. 1700, in Stan Hywet Hall & Gardens, Hour 1. Antiques Roadshow is available to stream on pbs.org and the free ...

A magnetic compass is used to align the sundial. Around the outside rim of the compass, eight directions are engraved in (slightly abbreviated) French: Nord, Nouest, Ouest, Souest, and so forth.

Sundial and compass with perpetual calendar and lunar circles. Brass, part silvered, 6 1/8 x 5 3/8-inches. By Christopher Kohler, Dresden, Germany, 1677. Glass of compass box cracked, compass needle ...