Sundial called the "Navicula de Venetiis"

This is the best-known sundial in the collection of the more than two hundred items gathered by Piero Portaluppi and also one of the most important by reason of its antiquity, the refinement of its materials and the client who commissioned it. It was made in 1524 by the famous French mathematician Oronce Fine, who was also the author of a literary work on solar clocks. It was intended for the court: it bears the emblems of King Francis I (a salamander and lilies).
This instrument was a portable sundial: when the ship was orientated correctly towards the sun a plumb line thread with a bead falling from the mast cast its shadow on the dial. On the hull are engraved the series of the hours and two zodiacal scales, while the signs of the constellations appear along the mast. This is hinged between the two panels forming the hull so it can be inclined depending on the seasons.
The name comes from the form of the clock, which resembles a sailing ship used in Venice.