Dr Robert Sturm (Austria)
This is the third of four articles on the quarries of the ancient world and later, and, in particular, the marble that was quarried there and the works of art made from it. The first (Mining in Ancient Greece and Rome) was published in Issue 41 of this magazine and the second (Marble from the Isle of Paros – a tour of the ancient quarries) appeared in Issue 51.
The ancient methods used
An antique quarry is interesting because it is a place where raw material for buildings and sculptural works was extracted to specific sizes and shapes with the technical methods of that time. The mining techniques did not change very much from the earliest phases of human civilization until the end of antiquity, even though the methods used continuously improved over time. In ancient Greece, single blocks of the stone were separated by smashing several key holes into the rock wall, into which wooden wedges were driven. After that, the wedges were moistened, causing their expansion and the cracking of the block along the line of holes. For a better control of the rock fracture, long groves were carved into the blocks with iron tools, into which key holes were subsequently inserted. Alternatively, the blocks were completely split off from the rock walls by deep cuts in the rock and then separated from the ground using crowbars (Fig. 1).
Since archaic times, rock saws have also been used. In the Roman era, these tools were replaced by so-called ‘pendulum saws’, with single blades measuring 6m in length. The cutting efficiency of the saws was increased by using quartz sand that was suspended in water and flushed into the groove.
Work on the raw material mined in the quarry usually started at the place from which it was extracted. This is indicated by the many semi-finished columns, capitals, obelisks and sculptures that can be found at some of these sites. The most famous example of a half-finished sculpture is the so-called Kouros of Naxos, which is still attached to its block. The main reason for the preliminary work on the rock being carried out in the quarry was the high cost of renting transport, which became much cheaper after the removal of unnecessary rock ballast from the half-finished architectural pieces. Transport of the material away from the quarry was carried out using carts or, in the case of very heavy pieces, on specially produced slides. If the quarry was situated near the sea or in the direct vicinity of a river, transport of the material was preferably conducted along the waterway.
While in ancient Greece, quarries were generally in the possession of the state, in the Roman Republic, they mostly passed into private hands. Under Emperor Augustus, the founder of the Roman Empire, most quarries came back into public or imperial possession and were managed by public servants or leased to entrepreneurs. In the fourth century AD, Emperor Constantius, the father of Constantinus the Great, again tried to denationalise the quarries, but had only very marginal success.
For the heavy work including the separation of giant stone blocks, prisoners of war and slaves were mainly used. Along with these people, free craftsmen and soldiers were also used to extract and work the rocks. The main rock types, which were subject to extensive use in ancient times, included marble, limestone, granite, porphyry and sandstone.