Comparison of two XVIII century technical maps of Bologna, one copied from the other.

This study belongs to a research project, funded by the Fondazione Cariplo, which aims to investigate the ancient arrangement and appearance of three main Italian cities (Bo-logna, Milan, Rome), by means of some significant examples of historical cartography. In Bo-logna, the research is carried out by the University and the National Archive, also in collabo-ration with the Archiginnasio Library. The research presented here is focused on two Eighteen century maps of Bologna, the first one (1711-12) made by the surveyors G. Monari and A. Laghi, the second one (1745) signed G. Monari (the surveyor) and A. Scarselli (the engraver). The former represents the first ex-ample of a technical map of Bologna deriving from a thorough rigorous survey of the city, and the second is a reduced copy of the first one. The present study takes into account the modalities of copying of the second map from the first one, and the differences existing be-tween them, by means of direct analysis and metrical comparison of the two documents – digitized by means of high quality scanning – in a digital environment.