Roman baroque models and local traditional construction. The sanctuary of St. Ignatius of Loyola and its dome

The essay would analyze the singularity of the dome of the Basilica of the Sanctuary of St Ignatius of Loyola – a double shell in stone with a diameter of approximately 20 meters – designed by the architect Carlo Fontana (1638-1714). The architect never visited the worksite under construction, and the substantial isolation of the site compared to the principal cultural centers at the time, left ample room for the local craftsmen to make decisions on their own who. So, rather than being realized in masonry (as was plausibly conceived), the dome was found to be implemented by means of the application of complex stereotomic principles, giving rise to a unicum that has not again been encountered or equaled in the entire Iberian Peninsula. This choice constrained the technical realization of the work as a whole, obligating the implementation of identical ashlars for the inner shell, as the only possible way to simplify the operations was to use pre-fabricated elements, later to be carved with ornate figures and shapes. Furthermore, these shapes – not being geometric – represent an even greater conceptual effort in the workmanship, since every block of stone had to be worked individually so that the final image was uniform.