Avebury, Wiltshire

More uses for face masks

One of my favourite passages in Andrew Ziminski’s excellent book The Stone Mason: A History of Building Britain, is quite near the beginning, where the author describes his attempts at working sarsens, the materials used for the enormous prehistoric stone circle at Avebury and also for the nearby Dissenters’ Chapel. The chapel was originally built in 1670 using in part bits of sarsen obtained by chopping up chunks of some of Avebury’s standing stones. The point is that sarsen is very hard stone (up there with granite) and Ziminski wanted to try working it using the kind of tools available to Avebury’s prehistoric craftsmen. In other words he’d be working stone with stone – rounded lumps of sarsen or flint, which he’d use to pound away at the surface of the stone to cut into it or to smooth its surface.

Using stone tools like this, Avebury’s builders (working at some time between 2850–2220 BC) managed to prepare and position around 100 stones, as well as building a large circular bank and ditch – the resulting henge is so large that the modern village of Avebury sits inside it. And this stone circle is only part of the picture. It sits in a whole landscape of ancient sites – barrows, the causwayed enclosure of Windmill Hill, the stone circle at the Sanctuary, the vast mound of Silbury Hill – stretching for miles around. The integration of stones and landscape also makes Avebury a wonderfully atmospheric place – it is my favourite English prehistoric site. 

Ziminkski discovered that walloping away at a large lump of sarsen with stone tools like those used in the Neolithic soon raises a huge amount of white dust; since sarsen is made essentially of silica, this dust can be dangerous to human lungs. Anyone doing this Neolithic job in the 21st century needs a face mask. Even so, it took a whole day of pounding to produce about a square foot of approximately smooth stone. This might lead us to conclude that in Stone Age Avebury there was a lot of labour available, and there might well have been. But Ziminski makes another point. Like other kinds of stone, sarsen gets extra hard when it has been exposed to the elements for a long time. If you quarry stone that has been beneath the earth’s surface it contains much more moisture, or ‘quarry sap’ as stone workers call it. Stone containing all its quarry sap is softer and easier to work and it was probably knowledge of this secret that made monuments like Avebury and Stonehenge possible. And also buildings like the Dissenters’ Chapel, which Ziminski had come to Avebury to repair. For that job, the stone mason could use his modern steel hammer, punch, and claw tool.