«Per non dar moto alle fabriche»: l'ingegnere regio Scipione Basta e la costruzione della cappella Roano nel duomo di Monreale

«PER NON DAR MOTO ALLE FABBRICHE»: THE ROYAL ENGINEER SCIPIONE BASTA AND THE CONSTRUCTION OF THE ROANO CHAPEL IN THE CATHEDRAL OF MONREALE. In December 1686 the Royal Engineer Scipione Basta, a personality still largely to be investigated but which seems to portend a specific expertise in techno-constructive issues and in particular in structural reinforcement, was appointed by the Viceroyal Government to draw up a technical report concerning some delicate constructive aspects of the project of the architect fra Giovanni da Monreale for the chapel commissioned by the archbishop Roano for the cathedral.Due to the particular configuration of the building to be constructed –a domed octagonal chapel built on a vaulted alley to allow the passage of the pre-existing public street– the engineer dictated a number of requirements in order to ensure not only the firmness of the building, but also that the thrusting elements of the new structure (arches, vaults and dome) with their stresses would not cause damage to the ancient Norman cathedral and in particular to its precious mosaic decorations.