Platinum Cloisonné enamel Perpetual World Time.
These are indications for what are called the Moon's Nodes. Ulysse Nardin Platin Uhren The orbit of the Moon is tilted somewhat with respect to the Plane of the Ecliptic (the common plane in which the Earth and planets appear to orbit). In ancient times these were known as the caput draconis et cauda, or Head and Tail of the Dragon (Harry Potter fans will recall that the first password to Gryffindor Tower in The Sorcerer's Stone is ""Caput Draconis.