License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Isidore Pils. Cleric (lower register; study for wall paintings in the Chapel of Saint Remi, Sainte-Clotilde, Paris, 1858); black chalk landscape sketch on verso of support, 19th century. The Metropolitan Museum of Art.