License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Bartolomeo Crivellari. Plate 1: cross-section of the Hall of the Institute of Bologna, which served as the residence for the Clementine Academy, with fresco paintings by Pellegrino Tibaldi in the vault, 1756. The Metropolitan Museum of Art.