Anonymous, The culmination of Renaissance ingenuity and scientific achievement: Celestial sphere with traces of a mechanism. (c1540-c1550)

Celestial sphere, two large brass fretwork hemispheres joined at the equator with two sets of rings. The first set consists of five parallel horizontal rings representing the Equator, Tropics of Cancer and Capricorn, and both polar circles as well as vertical colures and meridians intersecting both poles and crossing the equator at 30 degrees. The second set consists of six rings intersecting the equatorial poles at an angle of 23.5 degrees – this angle would allow the now-missing inner terrestrial sphere to consistently point to the north and south equatorial poles of the celestial sphere. Placed atop this set of 17 rings are the 48 Ptolemaic constellations and two non-Ptolemaic ones. The Lynx (LE LYNX) located between the Great Bear and Leo and the constellation of Eridanus, depicted as a naked female figure, were both added later. The planetary symbols and series of stars up to five magnitudes are engraved on the figures of each constellation. The celestial sphere is mounted on a graduated brass meridian ring held in place by two recesses on the horizon ring. One face of the meridian is stamped with a scale of 360 degrees, and an hour-ring and index is mounted at the North Pole. A set of four brackets support the horizon ring with engraved acanthus leaf decoration and foliage, which terminate in scrolls with a pierced opening holding a peg attached to the horizon. The upper face of the horizon features an inner scale of 360 degrees divided into 12 signs for the zodiac labelled in Latin and depicted with its symbol. An outer scale depicts the Julian calendar with the names of the months stamped in Roman capital letters. The first point of Aries coincides with the 11th of March. The 12 winds are engraved at the outer edge as blowing figures. The sphere is supported by a chased-brass circular base with four grotesque human figures amongst arabesque decoration. The sphere rests on a cylindrical marble stand with minor chips consistent with age., 86 × 33 × 33 cm