ABSTRACT
This study investigates the vertical dimensions of key elements in the elevation at San Carlino, to calculate the proportional relationships between them, and to establish whether constructive geometry could have been used in the design process. The key visual structures of the church interior and front façade were measured on antique prints. This suggested the presence of a number of proportional relationships common in constructive geometry. These predictions from constructive geometry were then tested against precise measurement data gathered from recent laser surveys of San Carlino. A series of correlations were found. In seven instances there was a match to within 3 cm or less, and in a further five instances the discrepancy was less than 1%. The findings of this study were that the processes of design ad triangulum and ad quadratum could indeed have established the position and dimensions of key elements in the elevation, including, in the church interior, the height of the wall columns and the main order, the height to the top of the pendentive zone, the height of the dome to the lantern opening, the position of the springing line, and the height of the church to the top of the lantern.
