Prehistoric Pottery at Flameworks (& The Hembury Bowl)
This is the Hembury Bowl. It’s curated and on permanent exhibition at Royal Albert Memorial Museum, Exeter. It was found by Dorothy Liddell in the 1930’s, whilst excavating the Iron Age Hillfort. During the excavation, the causewayed enclosure was found at the north end with a considerable amount of Neolithic pottery. The chronologies for this period were constructed by Stuart Piggott based on the assemblages and stratification of Windmill Hill which was excavated in the late 1920's.
It wasn't until the 1960's that Peacock used petrographic thin section analysis techniques to determine the provenance of archaeological ceramics. He determined that the Hembury bowl was made from gabbro clay from the Lizard Peninsula in Cornwall. This threw up the question - were the potters transporting the clay or the pots from the Lizard? Re-enacting a chaine operatoire (operational sequence) can maybe enlighten this quandary.
I dig out clay and don't make the pots on the site, I take it home with me to my workplace and make the pots there.
Chronology is vital here and the recent work of Alastair Whittle in “Gathering Time: Dating the early Neolithic Enclosures in Southern Britain and Ireland (Whittle et al, 2011)” sets out The Bayesian recalibration of older C14 dates highlighting the errors that had accrued in chronologies and pushed back the start of the Neolithic by between 1000-2000 years. The period under consideration in this project is in a range of two to three hundred years.
One of the earliest dates for the period is from Broadsands chambered tomb, nr Torquay, (Sheridan et al, 2008), at 3940cal BC- and there are a few sherds of quartz-tempered pottery associated with the human remains in the tomb. Hembury and Helman Tor, have the earliest C14 dates for enclosures in the region and were being constructed approximately 3700calBC. The C14 dates from Hembury were from residues on ceramic and Helman Tor from charcoal. (Whittle et al 2011). C14 dates for Raddon are based on charcoal samples and the enclosure was likely in use for only a hundred years (Whittle et al 2011).
The reenactment of a ceramic chaine operatoire is a lengthy labour intensive business. I’ve been teaching my prehistoric pottery course over the last 2 weeks and this has involved going out prospecting for clays, on Creusa Down. So as a team we have dug out gabbro clay in the Lizard, Cornwall from 3-4 locations. This involved deturfing, digging a hole and then auguring out the clay. We took a bucket from each location. The second step is then processing the clay until it is plastic enough to make pots. This is done either by wet or dry processing. Robin and Mallory, in the picture, did all the work (heroes)
Mallory is dry processing by crushing and sieving the clay and we wet processed the clay and then had to sieve it to remove all the stone. The wet slip is then dried on a plaster or wooden bat. My colleagues at Flameworks have remarked on the amount of work that is required to make this clay into a material plastic enough to make a pot. Contemporary studio potters normally use commercial bagged clays. We’ve made shrinkage and temperature test tiles.
When a new Clay is dug, tests need to be performed to test its plasticity, it’s shrinkage rate and it’s firing/ maturing temperature. Most clays will likely fire to 750*C before melting so we’ve made four tiles to test each clay. They will be fired successively higher each time starting at 750*C , then 950*C , 1150*C and maybe, if they don’t melt before this last high temperature, to 1250*C. If it is possible to fire them up to 1250*C maintain shape and performance with a fairly low shrinkage rate then we would have found a good potting, stoneware clay.
Once the test tiles have been fired, the various shrinkage rates can be worked out for dry ware, totally dry ware; shrinkage once fired at the successive temperatures. Most shrinkage occurs between wet/plastic stage. The best way to achieve plasticity is to age the clay for over a year.
Words & images : Angie Wickenden
