The most famous work by Hausmann, Mechanischer Kopf (Der Geist Unserer Zeit), "The Mechanical Head (The Spirit of Our Time)", c. 1920, is the only surviving assemblage that Hausmann produced around 1919–20. Constructed from a hairdresser's wig-making dummy, the piece has various measuring devices attached including a ruler, a pocket watch mechanism, a typewriter, some camera segments and a crocodile wallet. "Der Geist Unserer Zeit – Mechanischer Kopf specifically evokes the philosopher George Wilhelm Friedrich Hegel (1770–1831). For Hegel...everything is mind. Among Hegel's disciples and critics was Karl Marx. Hausmann's sculpture might be seen as an aggressively Marxist reversal of Hegel: this is a head whose "thoughts" are materially determined by objects literally fixed to it. However, there are deeper targets in western culture that give this modern masterpiece its force. Hausmann turns inside out the notion of the head as seat of reason, an assumption that lies behind the European fascination with the portrait. He reveals a head that is penetrated and governed by brute external forces. (https://en.wikipedia.org/wiki/Raoul_Hausmann)