After analyzing the spatial interaction between sculpture and column one ought to study the physical form of the column. Mies's columns were an absolute novelty in contemporary architecture, and his cross-shaped column was among the first reflective columns in architectural history. Both its cross-shaped section and its reflective surface can be investigated through Mies'ssources, Technically Mies's column consists of a loadbearing core and an external casing. There was a famous precedent in German architecture of the 19th century: August Stüler's columns for the Berlin Neues Museum ( ill.32 ). Mies certainly had direct experience of this building because it was located on the Museum Insel, behindSchinkel's Altes Museum, and it had been published in a posthumous book by the art historian Alfred Gotthold Meyer, Eisenbauten, in 1908 at the time when Behrens was designing the AEG Turbinenfabrik and Mies was his assistant. Meyer's text was the first overall analysis of the iron architecture of the 19th century, the first explicit appraisal of the artistic brilliance of engineers' technical culture, and of architects' understanding of the new techniques and materials. Twenty years later Walter Benjamin celebrated this book as a prolegomena to any future history of architecture with a historic-materialistic approach, a work that anticipated also Siegfried Giedion's book Bauen in Frankreich published in 1928's Meyer's book aimed at broadening the applications of Semper's ideas to the point of including also iron architecture that Semper considered not part of monumental architecture even though iron architecture occupied an important part of his treatise Der Stil it represented for him only a technical craft ( >Tektonik< in Semper's definition ). Mies never openly declared to have studied Semper's books but he nevertheless absorbed his ideas while at Behrens's atelier where beside Schinkel's work-he also learned about the Semrchitect Berlage and the book by Meyer.