Book restoration is the renewal and repair of books. Techniques include cleaning; mending and filling damaged pages; restitching and rebinding. The first substantial work on the subject was Alfred Bonnardot's Essai sur l'art de Restaurer les Estampes et les Livres which was first published in Paris in 1846. Further significant developments occurred as a result of specific events including the 1904 fire at the Turin National University Library and the 1966 flood of the Arno which damaged over a million items in the National Central Library in Florence.