At Priene, lying in the next valley to the south of Ephesus, the water supply was closely related to the availability of karst water on the site, still visible today on the mountain above the city. When Alexander the Great was invading this area in the early fourth century BCE, he located his base camp for further campaigns on the platform that became the Greek city of Priene, still called by its ancient name. In my 30 years of study of ancient Greco-Roman cities I was at first amazed and then enraptured by the interaction of these ancient Mediterranean peoples with the subterranean factors of the land they were building on. By the sixth century BC they had learned to harness the often invisible water to supply their common areas and individual houses. An awareness of geological processes and products flourished in a pre-scientific culture, because these people already had the most important facilitating attribute – the inquiring mind. For example, Priene engineers of the fourth-third century BCE designed a sophisticated device – a mixing valve, which prevents a possible overflow of water from the central channel of the street that receives drainage from flanking residential districts. We found it built into the end of Priene’s main street, under the gate. By the inclusion of a baffle below the gate, the water was diverted from the exit channel, spun in two different directions, trapping any debris that might be lodged in the water channel. Without moving parts, this device solved what was always an unpleasant and unhealthy problem. In all water-related activities, Greeks and Romans were keenly aware of the geological base. Urban sites were chosen for their underlying workable stone and clay that could be used for defensive city walls and for the structures within. Cities in the Mediterranean area were almost always built on limestone – of all the cities I have studied, only Morgantina was built on sandstone, a decision which brought some awkward construction problems, especially at the theatre, where from lack of proper foundations, one side collapsed more than once, and an accompanying row of two-storey shops was never finished. City builders everywhere made a point of securing essential spring water for drinking, whether adjacent or at a distance from the city gates. The longest water line that I know of was a Roman one that stretched 60 miles into the northern hinterland of Constantinople – Istanbul today. Priene drain: operates in three dimensions. The left side of the gutter goes into a cul-de-sac that creates a horizontal eddy, the right side follows a dip in the gutter floor, creating a vertical eddy. Working together they collect rubbish in a gyre, out of which it can be scooped.
Geological section of Priene. The town’s centre is indicated by the three columns. Varieties of marble are suggested by block patterns in the layers. Local builders preferred the gray, thick bedded massive stones comprising the terrace and mountainside under and behind the town. The alternation of marbles with schists facilitated the appearance of springs (Gungor and Alkan, 1998) below: Roman water supply and drainage system at Ephesus, based on extensive field work and computer modelling (Ortloff and Crouch 2001). Supply lines provided water for public display in fountains and baths, supplementing traditional springs, cisterns and wells. Drainage of used water and wastewater was by gravity flow to the harbour.
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