This article concerns a multi-faceted area of research that currently remains open to many possible developments, here presented simply as a series of calculated and concise conjectures. Along this path of exploration, we delve into the many interdisciplinary contributions that feed the exciting, ongoing debate about one of the most important monuments in the history of western architecture: the Tholos of Delphi’s Sanctuary of Athena Pronaia and its stone roof. The basis for this study is the consideration that the art of “stereotomy”, that is the cutting and shaping of stones to vault structures of great importance, was not the exclusive prerogative of Philibert de l’Orme of France, nor of the medieval master builders of the gothic cathedrals of Northern Europe.
On the contrary, the application of this technology was already widespread in the Hellenic world during the fourth and fifth centuries B.C., having perhaps been adopted from the ancient Egyptians. Notably, it was not imported by the Roman empire, which instead favoured the application of the load-bearing properties of grand masonry masses and the binding power of pozzolanic concrete.
Archaeological findings testify as to how the art of “stereotomy” was employed by Ictinus himself in creating the Temple of Apollo at Bassae, Greece (Pausania, K. Cooper), in a way similar to how today we believe the Parthenon was actually built. In the Twentieth century crucial discoveries about the “tiles” of Delphi (Jean Bousquet, Roux e Gottlob, Joko Ito) indicated that this technology was widely used in other round temples (Olimpia, Epidauro) and even in other kinds of structures (...).
The authors of this article delve into the unresolved debate regarding the question of the roof of the Tholos of Athena Pronaia at Delphi, in the archaeological site of Marmarià, disregarding the already amply discussed hypothesis that the roof was built using trusses and supporting substructures which have long since vanished without a trace. The research we briefly outline here has several aims beyond the main goal of verifying the structural equilibrium of a vault constructed solely from stone tiles like those catalogued and conserved in the Museum of Delphi. Using a virtual reconstruction of the original tiles as well as physical models, and analysing the shapes of the grooves and recesses of the artifacts, a structural roofing element was created. This element can be aggregated in a reciprocal spatial structural system, which takes the form of a dome built on the spherical section of a shell with an outer diameter of 800 dactyls, or about 15 meters. This study has opened up vital new questions to be examined, which the authors intend to investigate further: from the matrix of the platonic geometry that generated the concept and the form of this research project, to the analysis of the probable cause of the collapse of the elements under consideration, further referencing to the exclusion of merely decorative functions (acroteria, metopes, eaves, etc), which certainly underestimates the determining role of their weight in equilibrating the entire structure.