The Cannon, 1518, Albrecht Dürer, German, 1471-1528, 8 9/16 x 12 1/2 in. (21.75 x 31.75 cm) (plate), Etching on iron, Germany, 16th century, The toolbox on this cannon bears the arms of Nuremberg, Albrecht Dürer's birthplace and home to several of Emperor Maximilian's arms foundries. What's more, the Turk at right is believed to bear the face of Dürer himself. The artist made just six etchings on iron, probably abandoning the medium because he was dissatisfied with the coarse, crumbly lines that resulted. Although he preferred the more controlled vocabulary of engraving, Dürer exploited the freedom of the etching needle in the muscular tree and distant landscape, creating naturalistic effects that would have a lasting impact on the artists of the Danube School, who made prints focused solely on nature.