This is a very uncommon collection and, with so many different versions, it is difficult to tell how many plates are supposed to be included. Many of the plates are unmarked, but the few that are marked give credit to G. Bianchi for the etchings. Illustrations depict the major works in the field of civil and religious architecture under Pope Pius IX in Papal cities such as Rome, Lazio, and Marche. Some areas shown are: archaeological excavations, restoration of civil and religious monuments, works of art, public buildings, factories, bridges, roads, railway lines educational institutions, astronomical observatories, churches and temples, hospitals, and barracks.