For the last 2 weeks of September 2016 we supported an inspiring archaeological project at East Chisenbury in Wiltshire, which has a remarkable Late Bronze Age/Early Iron Age midden (rubbish) site, an enclosure ditch and evidence of settlement.
A section of ditch in Trench 1 at East Chisenbury. Photograph ©National Trust/ J. Tomlin
The project was organised and run by Breaking Ground Heritage and Operation Nightingale, who use archaeology and heritage as a route to recovery for injured service personnel. I was there to promote the experimental side of archaeology, reconstructing the ceramics coming out of the ground and going through the pottery-making processes with an eye to the prehistoric.
The exercise of pottery reconstruction allowed the retired servicemen and women to really get a feel for building a pot, for looking at where to add the next coil, how to smooth and blend, what hand movement or tool causes what pattern in the clay, and then to look again at the archaeology and see it in a different light.
One of the team working on a furrowed bowl (she ended up making 4 pots). Photograph ©National Trust/B. Clifton
Pottery-making on site at Chisenbury was not only about experimental archaeology, however. Along with being a valuable social experience, it is also significantly about the individual’s responsiveness to the clay and about the focus and deliberation that naturally occurs when building a pot (…or sculpting a tortoise/whale/badger/giraffe – we had all four). For many people, pottery-making has hugely therapeutic qualities where the mind can rest and be totally absorbed in an activity – something I hope can at least help support the recovery of serving and ex-service personnel.
All of the pots together before some were carefully placed into the firing pit. Photograph ©National Trust/B. Clifton
On the final day we fired some, but not all, of the pots in a pit firing (bonfire). The two preceding weeks had been quite cold and damp for the clay (which we were trying to dry out!), so I had given a frank warning to all the potters that the likelihood of their pot’s survival in a bonfire would be minimal. In other words ‘if you’re attached to your pot, don’t put it in the fire’.
The firing day was warm, but there was a strong wind which was blowing straight across the firing area. This would result in two things: 1 – the fire would burn quickly (not what we wanted) and 2 – there would be quite a bit of thermal shock from the cold wind and the hot fire, both of which can cause pots to crack. When firing in a bonfire (as oppose to an electric kiln) a certain amount of control is lost over the rise and fall of heat; add damp pots on top of this and I’m surprised we had any pots which survived – but we did!
Some of the survivors after the pit firing. Most came out completely black, some with black and brown patternation. Photograph ©National Trust/B. Clifton
The Blackening Techniques in a Nutshell
Many prehistoric pots appear black. This is due to certain conditions in the fire: reduction and carbon blackening or ‘smudging’.
Reduction is a complex chemical reaction involving the movement of electrons (Ceramic Arts Daily), but is usually generally described as starving the fire of oxygen so that it draws it from the iron oxide in the clay and turns the pots black. The opposite of this is oxidation, where the pots may be red, grey, white etc. depending on the clay used. Pots can be a mixture of reduction and oxidation, which is why one pot could be, for example, full of reds, browns and blacks.
Carbon blackening occurs when pots are surrounded by combustible materials (such as sawdust) which are set alight and burn slowly until the fuel runs out, leaving black carbon coatings or smudges on the fired ceramics.
A combination of these and other conditions and variables can amount to really beautiful colourings of ceramics.
Many thanks to all the first-time potters who took part in this, and to Breaking Ground Heritage, Operation Nightingale and Wessex Archaeology for such a fantastic and stimulating fortnight. Thanks to Tom for supplying the majority of the wood for the fire, and Dave for the straw.
Lastly, rest in peace to Scott who was so brilliant last year at Chisenbury. I know he valued the pottery-making sessions and found them hugely therapeutic both physically and mentally. I was glad to have known him, if for a short while.
Breaking Ground Heritage:
For a summary of the site see Wessex Archaeology’s blog post here: http://www.wessexarch.co.uk/blogs/news/2016/09/30/site-operation-nightingale-and-breaking-ground-heritage