“... May God Protect You from Lightning ...”

This study analyzes one of the first, and most important, installations of a lightning conductor system in Italy, applied to a monumental complex: the Abbey of Monte Cassino, in southern Lazio. This study - in addition to a profile of the designer of the system, Feliciano Scarpellini, an astronomer and professor of physics, a leading scholar and scientific investigator in Italy during the late eighteenth and early nineteenth centuries, the founder, among other things, of the Accademia Caetani, which later became the Accademia dei Lincei - analyzes the relief and planar-altimetric arrangement of the lightning rods, which, together with other partially unpublished documents, provides several important measurements of the Abbey, which, completely destroyed by ferocious combat during the Second World War, left little graphic evidence that describes it geometrically. It also outlines the profiles of other scholars who contributed in various ways to pre-war lightning-rod system installations.