Piranesi at the Nymphaeum of Egeria. Perspective expedients

In the year of the birth anniversary of the important Venetian artist, the paper aims to contribute to the great amount of studies conducted on the figure and work of Giovanni Battista Piranesi. After a brief presentation of the previous researches concerning aspects of the interpretation of Piranesian spaces, the contribution proposes a geometrical analysis of the "Veduta della fonte e delle spelonche d’Egeria fuor della Porta Capena or di S.Seb.no", collected in the "Vedute di Roma" (1748–1778). The subject represented is the so-called Nymphaeum of Egeria, an archaeological structure still existing today, located in the Appia Antica Regional Park. Through the analysis, based on the principles of the perspective method and compared with the Nymphaeum survey, it was possible to identify the fundamental elements (horizon line, ground line and projection centre) of the perspective approach adopted by Piranesi. Despite the approximations due to the nature of the data used, the author’s attempt to manipulate perspective is evident. He, in fact, introduces the expedient of moving the projection center away from the picture plane, gradually considering parts of the structure closer to the observer. The conclusions outline the possibility that Piranesi has adopted these stylistic choices in order to make the overall view and details of the archaeological site more comprehensible at the same time, implementing an operation that makes the side walls less foreshortened.