Sainte-Geneviève Library

In the reading room of the Sainte-Geneviève Library, Henri Labrouste let the iron show. A spine of sixteen slender cast-iron columns runs down the middle of the room. From them spring openwork iron arches that carry two barrel vaults of plaster reinforced with iron mesh. Left uncovered, it works with the tall windows to give the room space and light. Modernists later admired it as one of the first monumental buildings to put new technology on display.

The library needed a building because it had lost one. Its collection descends from the Abbey of Saint Genevieve, where a library is first recorded in 831. Vikings sacked the abbey, the Wars of Religion scattered manuscripts, and the Revolution confiscated everything. The director, Alexandre Pingré, kept the books together. Then the library lost a long dispute over its rooms in the old abbey with the school now called the Lycée Henri IV.

The replacement was the first building in Paris designed specifically as a library. It opened on 4 February 1851 on the Place du Panthéon. Its façade is exactly as long as the reading room, and its main ornament is a list of the names of scholars. Labrouste placed most of the books where readers could reach them: 60,000 in the reading room, 40,000 in the reserves.

The design travelled. Charles Follen McKim took it as his model for the Boston Public Library. Between 1928 and 1934 the tables were turned across the room to double the seats to 750. The library now holds around two million documents and counts as a national, university and public library at once, an overlap explained in our guide to types of libraries.