Experimental Archaeology: Building a pottery kiln

This experimental project with Year 8 students (12–13 year olds) in the summer of 2001 was so successful we thought we'd leave it on-line for anyone else who fancied having a go!

The students of Barton Court Grammar School, Canterbury, Kent (UK) do something different at the end of the summer term. They take part in Enrichment Week. This is a time when the school curriculum is suspended and youngsters choose from a variety of fun activities to widen and 'enrich' their experience beyond normal lessons.

In 2001, Andy Jeffries, Head of Science at Barton Court Grammar School asked if the Trust would like to take part in Enrichment Week. A loose theme of 'Past and Future' was coming together and we suggested building a 'clamp' kiln in the school grounds - the kind of structure which would have been used to fire pottery in prehistoric or early Anglo-Saxon times. Alan Ward at CAT had some experience of doing such things with adult students and was more than willing to give it a go!

Fantastic result!

Experimental firings by their nature can be unpredictable! In this case, the whole project was a success from beginning to end. The students involved were impressed that this was the hottest kiln Alan had ever built and that there was such a fantastic recovery rate for their pots and tiles - and it all happened at their school!

The project was spread over two and a bit days and was great fun for everyone involved. Many thanks go to Andy Jeffries and Angela Duignan at Barton Court for their enthusiasm and co-operation with planning and seeing the project through and to all the youngsters who took part.

1st Stage: Making the pots and tiles

Two builder bucketfuls of Gault clay were dug out of a slip at the Warren at Folkestone, Kent. The clay was formed into orange-sized balls and then different tempering materials were worked in. A temper will open up the clay body, allowing any moisture to safely escape during the firing process. Some balls of clay had handfuls of Margate beach sand added, others had dried pine needles (from an old Christmas tree). The clay needs to stay pliable so adding a little water helps. Think of making pastry - not too sticky - not so dry that it cracks apart.

Due to time available, the students were not involved with clay preparation but took over at the pot making stage in their Science lab at school. They used the lump method and coiling to make a variety of pot shapes, loosely based on prehistoric and Anglo-Saxon styles. Various pieces of wood and bone were effective tools for decorating. Some children also made simple tiles, with more freestyle decoration!.

Their wares (about 25 items) were then left in an airy room for one week to dry out.

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2nd Stage: Building the 'clamp' kiln

Behind the school was a good open and safe site for the firing (away from buildings and trees). Staff at the school had gathered the basic materials needed to build a kiln. Quanitities are approximate:

• About 6 barrow loads of small logs
• About 2 dozen squares of rough turf
• Some soil for plugging holes in kiln dome
• Pet shop bag of straw and small twigs for kindling

First, we gave the students a Health and Safety talk about what to do and (more importantly) what not to do! They then got stuck in with the manual work and levelled the site with spades. Next they built a shallow log platform and laid their works of art on top. A lattice work of logs was laid around the pots and gradually built up until all were enclosed. A 'flue' was left open on one side and stuffed with straw and kindling. Finally the dome was covered with rough turf and soil.

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3rd Stage: Lighting it!

A bit of cheating with a box of matches... and soon the fire was well under way. Smoke drifting out from small holes in the dome showed that the body of the kiln was heating up nicely. There's something about watching an open fire and several of the team stayed around for a while. Building the kiln had been a couple of hours work.

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4th Stage: Next day - have any survived?

The kiln was left to fire and smoulder away overnight. At 9am the next morning much of the superstructure had burnt down but there were still red hot ashes deep inside. Having got this far we didn't want to demolish the remains too quickly. There was a risk that any complete pots would explode on immediate contact with the cooler air outside the kiln. So we very slowly raked away the ashes and charcoal. By midday all was revealed with a virtual 100% survival! The pots were spread around the kiln site to cool completely and were then triumphantly carried away by the youngsters.

The only surviving evidence for our kiln was a burnt patch on the ground... Will archaeologists of the future be able to work out what happened there on a July day in 2001?

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