From Bernard Frischer, “The Digital Roman Forum Project of the Cultural Virtual Reality Laboratory: Remediating the Traditions of Roman Topography” (2003):
As far as we know, the great Florentine architect, Leon Battista Alberti, was not aware of the work of Poggio or Biondo when he wrote his Descriptio urbis Romae in the 1440s. This little book describes how to measure the distances between buildings in Rome and how to plot them on a map. In fig. 2 [Image Above] can be seen the circle that Alberti lays out surrounding the city so that all points within it can be referenced precisely by the circle’s coordinates. No map of Rome from Alberti’s hand survives, but it was not long before Pietro del Massaio illustrated a Florentine edition of Ptolemy’s Geography with a map of Rome drawn according to Alberti’s method (fig. 3) [Image Below]
