License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Stefano della Bella. A mortar and a cannon, both mounted on carriages, a soldier shown from the back stands to the left, from "Equipment needed for Fortification" (Recueil de diverses pièces très nécessaires à la fortification), ca. 1638–43. The Metropolitan Museum of Art.