First hypotheses on the geometric genesis of the dome decoration of S. Maria del Monte Church in Caltagirone

This paper presents the first results of a research focused on the geometric genesis of the decoration of the dome of S. Maria del Monte in Caltagirone, near Catania. On the basis of similar studies carried out on other examples of semi-circular profile domes with lozenge-shaped coffering decoration, the aim is to identify the process by which the preparatory scheme for the appli-cation of the stucco used for the decoration was traced, and what the geo-metric matrix of this scheme could be. For the decoration of this dome, de-signed by the architect Longobardi Savalza around 1810, the hypotheses of both two- and three-dimensional curves were examined, taking into account the raised profile of the dome. In particular, the investigation focused on the hypothesis of a skiagraphic projection of the three-dimensional curve of the decorative scheme directly onto the dome inner surface, generated from the intersection of a conical light beam with the inner shell of the dome.