 The work of Frontinus on the aqueducts of Rome and Vitruvius's "De architectura" were preserved in very poor manuscripts until Giovanni Giocondo edited them in the 1430s, for presentation to Pietro.As an epigraphist, Pietro compiled ancient inscriptions and collected many ancient artefacts.The "Codex Hamilton", MS 254 in the Staatsbibliothek zu Berlin, was such an epigraphic collectanea.