This model of the solar orb shows the Sun lodged in a system of three partial orbs. The third—which lies between the external and internal ones—carries the Sun around the Earth on an eccentric path relative to the Earth. This is the physical equivalent of the geometrical-mathematical theory expounded by Ptolemy in the Almagest. The model is carried by a brass satyr on a turned wooden stand. Provenance: Vincenzo Viviani bequest.