In his guide Promenades au musée de Saint-Germain, published in 1869, Gabriel de Mortillet described all the rooms open to the public. At the time the guide was published the mezzanine was not completed. The first room was already allocated to monuments containing inscriptions and particularly to Gallic mythology. The second room was temporarily home to objects relating to the Roman conquest of Gaul. It contained several models, including the plan of Alise and reconstructions of catapults, as well as material discovered during the excavations at Alise-Sainte-Reine and Mont Beuvray.