This example of 20th-century architectural literature presents Siegfried Giedion's vision of architecture in the industrial era and his response to technological advances in the production of key building materials. The author shows how iron and reinforced concrete allowed the construction of buildings of unprecedented size and openness in the 19th and early 20th centuries. Focusing on the radical possibilities of skeletal support structures, he celebrates uses of these materials in buildings from the Eiffel Tower and the Crystal Palace to glass-canopied railroad stations, department stores, and exhibition halls.