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Saturday, 30 May 2020
The Romans knew that crossing rivers was often the most difficult part of a journey by road. People might get wet or lose possessions when crossing, and if the river was particularly full there might be a long delay.
Fords could be built up where the river was wide and shallow. Large quantities of stone and rock would be dumped into the river to form a firm foundation. On top of this was laid a flagstone surface, like an underwater road.
Bridges were more effective where rivers were deeper or narrower. A narrow stream could be crossed by a single stone arch, which supported a humped road surface above.
Wider rivers had to be crossed by bridges with more than one arch. Each arch was supported midstream by an artificial tower built up from the riverbed.
First the engineers hammered a circle of wooden stakes into the riverbed to form a watertight compartment. The water was pumped out and workmen dug out the riverbed to remove loose mud and reveal a firm surface.
A stone tower, called a pier, was then built up to stand about 3 metres above the river surface. The tower was usually wider and stronger at and below the water surface so that it could withstand floods.
On important roads the bridge was completed by building a stone arch between each pier. On less important roads wooden beams connected the piers. The road surface was then built on top.
The Romans sometimes built large arches over roads. These had no practical purpose, but were ornamental structures built to mark boundaries or commemorate famous events.
At Richborough in Kent there was a vast arch over the road that led up from the docks to the fort. This was the main military port for Britain. All soldiers entering or leaving Britain had to march through this arch.
In Rome a series of triumphal arches were built over the sacred road. These stone arches were decorated with carvings of battles and campaigns won by the general who was being honoured in the triumph (see page 202).
In the Mycenaean Period the Greeks erected strong defensive walls of stone, though most houses and other structures were made of wood. The skills of stoneworking were lost in the Dark Age.
Until about 650bc the Greeks built all their buildings out of wood or brick, using thatch for roofs. A few roughly shaped stones were used for foundations and around doorways.
When the Greeks began to build in stone they based their designs on that of the wooden structures that were being replaced. For instance temples had stone columns based on pillars carved from single tree trunks.
The Greeks used stone architecture at first only for temples, but later it was used for all types of public buildings. Gateways, tombs and government offices all began to be built in stone.
There were three basic types, or orders, of Greek architecture. Some buildings were built using just one order, others used two or even all three.
The Doric order was developed in mainland Greece around 650bc. The columns had no bases and a plain square capital. The space above the columns had small sculptures.
The Ionic order appeared in Ionia around 600bc. The columns stood on square bases and had capitals in the shape of rounded scrolls. The space above the columns had a toothed decoration with( ) out sculptures.
The Corinthian order developed later and was more elaborate. The columns stood on large bases and were topped by capitals carved in( )to the shape of stylised acanthus leaves. The space above the columns was carved with a long, continuous sculpture.
Sometimes a column would be carved into the shape of a woman and became known as a caryatid. This was most usual in buildings of the Doric order.
Most stone buildings were square because those were easier to build. However a few temples, called tholos, were round.