 Cast iron was used for the construction of large domes, often incorporating glass, as early as 1811, with the glass dome of the Bourse de commerce in Paris.The central four storey circular hall and towering glass dome of the long-demolished 1849 London Coal Exchange was an early and spectacular use of the material as both structure and architecture.The 1872 George Peabody Library in Baltimore is a similarly elaborate atrium with glass roof, where all the structural members are also decorative and made of cast iron.The lofty glass roof of Milan's Galleria, built 1865-77, is both a dome and glass roofed shopping arcade, the grandest ever built.