Quadrant signed by Giovanni Battista Giusti and set for latitude 43°40' (Florence). The front carries a degree scale, with markings for the tropics and the equator, hour lines for Italian hours, a shadow square and a "Tabula Solis motus" [Table of the motion of the Sun], indicating the Sun's entrance into the zodiac signs. On the back is engraved a windrose divided into eight 45° sectors with the names of the winds. In the center of the windrose was a magnetic compass (now missing). Provenance: Medici collections.