License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Gustave Ernst. <i>Musterblätter enthaltend die anwendbarsten Jagdstücke u. Arabesken für Büchsenschäfter, Graveure etc.</i> (Zella bei Gotha, n.d. [1849/50]) (Patternbook of Engraved Designs for Firearms Ornament), from the workshop of Louis D. Nimschke (1832–1904), ca. 1849–50. The Metropolitan Museum of Art.