Adolph Menzel’s Das Eisenwalzwerk, or Moderne Cyklopen (The Iron Rolling Mill, or Modern Cyclopes ) from 1875 depicts an analogy central to nineteenth- century thought, namely, that between the human motor and the combustion engine. The painting visualizes the differing rhythms of these two “machines” and the entropy produced as a result of that difference. The painting’s reflection on labor also elaborates an allegory of the activity of painting. Such an allegorical reading, motivated by particular attention to the objects placed in the painting’s foreground, entails a reevaluation of Menzel’s self-understanding and of the changing nature of allegory in nineteenth- century painting. In this instance, allegory operates not through identification but by means of analogy.