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. After Dada Friendship with Schwitters Huelsenbeck finished his training to become a doctor in 1920 and started to practice medicine; by the end of the year he had published the Dada Almanach and The History of Dadaism, two historical records that implied that Dada was at an end. In the aftermath, Hausmann's friendship with Kurt Schwitters deepened, and Hausmann started to take steps toward International Modernism. In September 1921, Hausmann, Höch, Schwitters and his wife Helma undertook an 'anti-dada' tour to Prague. As well as his recitals of sound poems, he also presented a manifesto describing a machine "capable of converting audio and visual signals interchangeably, that he later called the Optophone". After many years of experimentation, this device was patented in London in 1935. He also took part in an exhibition of photomontages in Berlin in 1931, organised by César Domela Nieuwenhuis. In the late 1920s, he re-invented himself as a fashionable society photographer, and lived in a ménage à trois with his wife Hedwig and Vera Broido in the fashionable district of Charlottenburg, Berlin. Hannah Höch - by now herself living with a woman, the Dutch author Til Brugman – left a sketch of Hausmann around 1931: "After I had offered to renew friendly relations and we met frequently (with Til as well). At the time he was living with Heda Mankowicz-Hausmann and Vera Broido in Kaiser-Friedrich-Straße in Charlottenburg. Elfrided Hausmann-Scheffer, Til and I went there often. But I always found it very boring. He was just