Santa Margherita at Montefiascone and Carlo Fontana's Knowledge on Dome Construction

This paper presents a study of the dome of Santa Margherita in Montefiascone, built in 1670- 1672/73 by the architect Carlo Fontana (1638-1714), and an analysis of the technical construction knowledge upon which it was based. The paper questions Fontana's 1673 manuscript justification of the dome's design, and compares the architect's manuscript presentation of the built dome with the evidence that emerges from a new architectural survey of the church and dome executed by the present author. The paper aims at investigating the way in which Carlo Fontana gathered, handled and interpreted information about dome construction, and how he went about synthesising past and current technical knowledge. The paper studies Fontana's Montefiascone experience as the starting point for his development of a set of influential rules for the construction of single shell domes that he published in 1694.