Against Gravity

Charles Stewart

Modular Design in the Vaulting of Early Byzantine Cisterns and Reservoirs
A recent publication dates the grand reservoir at Constantia (Salamis), Cyprus, to the early seventh century. Supported by 36 piers which formed 52 bays, the Constantia cistern would be the largest vaulted structure on the island. It was intended to be a showpiece; built conspicuously above ground to serve as a pendant, facing across the agora towards the famous Temple of Zeus (which had been converted to a church). In investigating the structure, wider questions have arisen regarding the development of Byzantine cisterns compared to earlier Roman designs. In Italy and North Africa, the Romans achieved a high-level of sophistication in their monumental waterworks; they covered their cisterns with long continuous barrel-vaults. In contrast, beginning in the fifth century, the eastern Roman provinces seems to have broke from this tradition by incorporating domical or groin-vaults. Recent surveys and excavations of Byzantine and Umayyad cisterns/reservoirs in Palestine as well as new architectural studies in Alexandria (Egypt) indicate that the driving motivation for this redesign was use of modular units based upon the quadratus; that is, “square schematism” appears to be the underlying principle. Such techniques may have influenced the design-process of Byzantine and Umayyad religious buildings in the seventh and eight centuries.