Famous map of the Tiber river basin, from the Nera to Gavignano, delineated by Andrea Chiesa and Bernardo Gambarini. The plates delineate with the maximum scientific rigor that the instruments of the time permitted, the river basin from the Nera to Gavigano, and are accompanied by profiles, sections, views of bridges, etc. After the disastrous flood of the Tiber in 1742, Pope Benedict XIV commissioned the two Bolognese engineers to map and study the course of the river, understand the reasons for the floods and propose remedies. The result was the creation of the map of the Tiber, which was engraved by Carlo Nolli, and two reports with proposals to reduce the damage of the floods that were published under the title 2Delle cagioni, e de' rimedj delle inondazioni del Tevere" by De Rossi in 1746.