Geometry and Rectangular Ratios: Serlio’s Villas in the Vienna Manuscript and Book VII

This paper deals with the comparison between the manuscript preserved in the Nationalbibliothek in Vienna - a preparatory work for Book VII of Sebastiano Serlio - with the printed volume, paying particular attention to the drawings and their relationship to the written text. In particular, the comparison refers to the initial section of the book, dedicated to the presentation of 24 ideal villas. The differences between the manuscript and the book noted by historians, in the case of the villas concern both the text, which is punctually rewritten in Book VII, and, to a lesser extent, the images. In this research, variants and invariants in the plans are examined with respect to geometric, proportional, morphological and topological aspects, which have not been investigated so far. The use of geometry and rectangular ratios as compositional criteria is the main reason for attention in the analysis. Five emblematic case studies, through the techniques of graphic analysis, interpretation and digital representation, develop the main observations.