Breaking with the neoclassical current dominating in the middle of the 19th century in Europe, Henri Labrouste erected in Paris, in the heart of the Latin Quarter, a compact and stripped-down building in which stone and an industrial material, iron, hitherto reserved at bridges or stations. It is here exhibited and magnified in the large reading room. This bias astounded Labrouste's contemporaries and was hailed by Le Corbusier as the first step towards "modern architecture".

The serie : An ongoing series of films devoted to the most remarkable achievements in modern architecture, from the works that heralded the birth of the modern style at the end of the 19th century to the latest designs by today's top architects. Each film examines the structure of the building, the architectural techniques as well as its cultural and historical influences. By examining a key building in detail the series brings light to its rôle in the evolution of architecture.