23 October 2010

The Giant Norias of Hama – Magnificent Waterwheels of the Past

Their name translates from the Arabic as wheel of pots and for centuries the norias of Hama lifted water in to small aqueducts to irrigate the fields surrounding the Syrian city.  Today there are still seventeen of these magnificently engineered wheels left but are mostly for display purposes only, as it were.

Although there is evidence that there were Norias around the city during the Byzantine era which ended in 1453, the Norias of Hama date from the a little later.  It is thought that they were started in the Ayyubid dynasty in around the twelfth century and enlarged in the Mamluk era of the fourteenth. 

It was at this point that the Mamluk reconditioned, increased and enlarged the amount of Noria in the city as their influence grew.  At one point in what we call the medieval era there were over thirty waterwheels in the city which took water from the Orontes river.   The city must have seemed like a metropolitan oasis.

Each of the wheels can be anything up to 20 meters in diameter (close to 70 feet( and the river water is channelled in to a sluice on the wheel.  This flow then forces the wheel to turn and wood boxes raise the water upwards.  At the top of the wheel there is an artificial channel in to which the water is discharged.

Using gravity, the water then flows through aqueduct channels to either households or farms in the vicinity.  Just as math was used in the construction of the waterwheels so it was in working out the times at which people had access to the water.  As a precious commodity it was important that it was shared fairly.

There are no other mechanical processes involved in the purpose of a noria – the power it produces is not used to run a mill for example.  The undershot of the wheel has a rim consisting of a number of containers and they lift the water upwards.  Conceptually it is similar to the hydraulic ram.

The largest noria in Hama is the al-Mohamadiyya, the purpose of which was to supply the city’s Great Mosque with water and its aqueduct is still there – or at least part of it - it does end rather abruptly about one hundred meters away from the noria.  Work started on this greatest of the wheels in the fourteenth century, at about the same time as Dante wrote The Inferno.  It is the largest noria in the world.

The origins of the noria are obscure but it is thought that they were invented in India or the Hellenistic Near East in the centuries preceding the birth of Christ.  It is also believed that they were pivotal in the Muslim Agricultural Revolution which started in the eight century and lasted several hundred years.  Islamic Spain also used the noria and there are still a number there too.

The noria of Hama were almost industrial in their capacity.  The largest has 120 water collectors and was capable of delivering almost one hundred liters of water each minute to the aqueduct.  Although none of the larger noria are now in use they are being maintained by the Syrian government so that future generations can witness the ingenuity of centuries gone by for themselves.