تفاصيل

M-4

Planetary Model: Mercury

This Ptolemaic Planetary Model of Mercury was crafted in 1582 by Girolamo della Volparia in Florence, Italy. This rare and unique sphere is made of bronze, and in three dimensions, shows the nest of crystalline spheres around mercury. A typical armillary sphere shows the two-dimensional mapping of the ecliptic, equator, tropics, and the poles in the sky, but this model is quite different since it is solely focused on Mercury. This model is based off of the crystalline spheres theory in Georg von Puerbach’s text, Theoricae Novae Planetarum. There are 5 inner rings. Spheres 2 and 4 are coupled together and demonstrate the oscillation in eccentricity. 1 and 5 are also coupled and demonstrate the precessional change in the apsidal line of Mercury’s orbit. Sphere 3 carries Mercury’s epicycle, represented by a small bead that is embedded in the sphere. This specific band is positioned incorrectly, possibly after a restoration that reconstructed the sphere wrong. The rings for the Cancer and Capricorn, and the Arctic and Antarctic circles are missing, but the zodiacal band is present, and is split into 12 sections and labeled every 5° with fine drawings of the zodiacal constellations. The sphere is mounted in a cradle with a horizon circle that is split into 4 quadrants, 90° each, and every 10° has a name of one of the winds in Latin. The cradle is attached to a long, tri-footed stand that is made of twisted iron. The feet are inscribed with a triangular design.

"Hieronimus Vulparia Faciebat Florentiae Anno Domini mille cinquento LXXXIl die Juni"

1582

bronze, iron

Italy

	Imperial(in)		Metric(cm)
Height			104
Width			48
Depth			48
Diameter
Circumference

	Imperial(in)		Metric(cm)
Height
Width
Depth
Diameter