The churches with aisles of arches and columns are an archetype of Sicilian architecture. From the Middle Ages to the 18th century, the preference for this plan resulted in experiments, evolutions and tests concerned with the science of building in a land exposed to the danger of earthquakes. Contrary to the recommendations dispensed and disseminated by the most authoritative treatises, the cases presented illustrate how metal tie-rods were used at construction sites in Palermo during the Modern Age when building these constructions. These elements were able to counter the thrust generated by the arches and vaults or caused by earthquakes on slender and isolated vertical structures like columns. The documents found concerning the const...