Pottery Making at the Bradford Kaims – Videos

This blog presents the video interviews from our open archaeology day which focused on prehistoric pottery.

The first shows Rachel Brewer, Assistant Supervisor, discussing the process she went through – first to prepare the clay and then to produce fired ceramics. The second presents some thoughts about the day from two of our students, Ewan and Ian.

 

Thank you for watching!

Stay tuned for more of our experimental sessions – coming soon!

Experimental Prehistoric Pottery

This week’s experimental blog is courtesy of Rachel Brewer, Bradford Kaims Assistant Supervisor.

 

Following on the heels of the beer brewing experiment, our Week 5 experimental archaeology project was an effort to make a variety of pottery vessels using only raw clay sourced from our prehistoric site here at the Bradford Kaims. We knew from previous seasons that the trenches and test pits often turn up natural clay deposits of varying colours and quality. We’ve also had a few examples of possible Neolithic and Bronze Age potsherds surface during excavation; so this summer’s experimental archaeology program seemed like a perfect opportunity to test out our prehistoric potting skills! Altogether, processing the clay, forming the pots, and the subsequent firing turned out to be a messy, fun and educational experiment for all involved.

 

Step 1: Gathering the clay

While digging a series of shovel test pits earlier in the season, we hit upon a substantial deposit of clay about 50cm below topsoil. Seeing a source of raw material for our pottery experiment, I dug out a bucket’s worth to begin processing. Though the clay was mostly light orangey-brown, there was a thin layer of grey overlaying that; it also gathered a good amount of silt and peat on its way out of our 20cmX20cm shovel test pit. Through processing, these colours and textures blended together as shown in the later photos.

 

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The raw clay.

 

Step 2: Processing the clay

This was the longest part of the process, due in part to my own inexperience and also to the wet conditions on site. I knew from research that the best way to process raw clay is often to dry it out completely, grind to a powder, sieve, and slowly reintroduce water until the clay reaches a workable consistency. I also knew how unlikely it would be that we could completely dry out that amount of clay in a timely manner, particularly when it was raining almost daily. So I opted instead for wet processing, which involved the help of several pairs of hands pulling all of the clay into small lumps and mixing/mashing it up with added water in a large plastic box. This part worked better than expected, and after a couple of days of minimal stirring, nearly all of the clay was liquefied.

 

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Slaking the clay on site.

 

At this point we poured the slip (liquid clay) through a sieve to remove the largest inclusions, mostly small stones and twigs. We could have used smaller screens and sieved multiple times for greater purity, but I chose not to since examples of prehistoric pottery found at this and other sites indicate that prehistoric people were not processing their clay to a high degree.

 

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Sieving the slip.

 

For about a week I attempted to do a daily pouring-off of the water that would accumulate on the surface, hoping that between evaporation and pouring off that the clay would thicken a bit every day. The couple of days I was able to let the boxes sit out in the sun did help, but it wasn’t working quickly.

 

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The slowly thickening slip.

 

On one sunny day I cut open a bin liner and laid it out on the grass like a small tarp, then I poured the thickened slip out on the plastic. This increased the surface area the sun could reach and it was noticeably thicker by the end of the work day, but it still wasn’t drying out fast enough. We had to rearrange the experimental schedule and move pottery back a week – I had only a week to get some workable clay and I was running out of ideas!

 

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Spreading out the clay to increase the surface area for evaporation.

 

My final effort involved pouring the clay into an old pillowcase, tying it closed with string and hanging it from a tree to allow the water to drain out with gravity and air. The better part of the week passed before I noticed much of a change, but much to my relief, the night before we were scheduled to make the pots we had somewhat sticky but relatively workable clay!

 

 

Step 3: Forming the pots

Before beginning our pot making, the students used rocks to crush up a few soft pieces of sandstone sourced from Trench 6; we used this sand as temper.

 

 

Since wheels were not used by prehistoric potters, the students learned to use the two most common methods of building pottery without a wheel: the pinch method (formed by pinching a solid ball of clay into the desired shape) and the coiling method (rolling out rings of clay, stacking the rings, and smoothing them together). A small amount of temper was added by each individual to their own allotment of clay. Of course we had some creative minds in the mix who ventured beyond the utilitarian forms like bowls and jars, and by the end of the day we had quite a collection of unique creations! We set everything we made on two log disks that would be easily moveable and would absorb moisture. After that we just had to let everything dry out completely to prepare them for firing.

 

 

Step 4: Firing

When it was time for firing, we began by building a small fire in our fire pit on site. Pottery has to be heated very slowly, so we began by placing the dried pots around the edge of the pit and then slowly moving them in close to the fire. Once the pieces were against the central fire, we began placing larger branches over and around the pots, completely covering them and creating a kiln effect. We kept a large fire burning for about an hour and a half, then allowed it to die down to coals. Since our time on site was limited to 5 hours and the pots needed to be cooling before we left site, we weren’t able to keep the pots firing for the ideal amount of time, which for our purposes would have been around 4 hours.

 

The final step of firing is allowing the pots to completely cool before removing them from the pit. Before we left site for the day, we dug the pots (none of which had broken!) out of the coals, stacking them against one wall of the fire pit and shoveling the coals to the opposite wall. We then covered the pots with a layer of grasses and sedge, placed a couple of metal sheets over the pit to protect the pots from rain, then left for the night.

 

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The fired ceramics hot from the fire.

 

Upon examining the cooled pottery the next day, I was pleased to see that none of the vessels had cracked or exploded during firing. Additionally, the pieces had fired, if not completely through, then most of the way through despite the shortened firing time. The fired pots are noticeably brittle and not completely water tight, but with a little more practice we could probably produce vessels that would be more serviceable. Since we accomplished our goal of using only raw materials from site and a fire to create prehistory-inspired pottery – and we had fun doing it – I’m calling this experiment a success!

 

Bamburgh Castle, Trench 3 – Hope Taylor nearly in reach!

As the level of Brian Hope Taylor’s 1974 excavations gets tantalisingly close, Trench 3 staff continue the process of gradually joining our excavations to his.

 

 

This is achieved through the removal of features and contexts which are stratigraphically higher in sequence including a stone wall (possibly 9th Century) last week, underneath which a number of finds were discovered. Our progress is described in the video below.

 

 

Bradford Kaims – Trench 14 Update

Trench 14 is actually a combination of two earlier trenches: 8 & 11. 

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Trench 14 and the stone feature within it.

Trench 8

Trench 8 was opened in 2013 and contained an artificial mound comprised of larger stones (30-45 cm in diameter) underneath a layer of smaller stones (4-10 cm in diameter). 

A quarter section was dug out to determine the depth of the mound, and we discovered a thin layer of peat under which lay a brushwood platform. As the season ended, we backfilled the quarter section and left it to future investigations.

Trench 11

Trench 11 was opened in 2015 in an attempt to further understand the stone mound feature by examining the surrounding area, as well as determining if any relationship existed between Trench 8 and the western end of Trench 9 – where a large post was discovered in situ at the end of season 2015. 

A paleochannel with layers of sand and brushwood was discovered at the southern end, which was less than a metre from the north end of Trench 8. One side of the channel edge looked like it may have been cut intentionally though further investigations are required to determine if that was the case. 

Also within the trench, we discovered over 10 pieces of wood around 6 cm wide & ranging from a half metre to one metre in length lying within the peat layer. Two had potential cuts in them, giving us an indication that at least a couple of them were used by early humans. 

So far this season…

We have expanded Trench 14 to include both Trenches 8 and 11, and are in the process of expanding the quarter section to give us a fresh understanding of the stratigraphy of the artificial stone mound and the brushwood platform lying under the peat layer. We also plan to expand the trench into the western edge of Trench 11 to understand if a relationship between 8, 9, 11 and 14 exists. Our plans are to extend into the palaeochannel to determine if it was cut intentionally and to excavate at least partially into the edge of the peat layer to discover if more worked wood exists. 

Week 4 in Trench 3, Bamburgh Castle

Last week’s main focus was on the north-east corner of Trench 3, as we were investigating the possibility that the area is in fact a Romano-British occupation layer. Questions have been raised recently about whether our previous identification of the area, as currently dating to around the 9th Century (believed so due to the beam-slot cut of our 9th Century Anglo-Saxon timber building) no longer holds, due to a large number of Roman finds appearing both this season and ones previously. This is not typically a cause for reinterpretation as artefacts from earlier periods do appear from time to time in negative features, such as pits and post-holes, but these were also appearing in normal stratigraphic layers. These finds include a section of a Roman glass bracelet, both Roman greyware and Samian pottery and, from a previous season, a Roman fibulae brooch.

 

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Part of the collection of Roman finds from the NE area of the trench.

 

To add to our current mystery, this area is cut by a number of negative features, which is making this puzzle all the more exciting to figure out. We have discovered a 9th century timber beam slot, an anglo-saxon post-hole, a high medieval pit and another possible anglo-saxon pit all in this corner. It is also difficult to see a relationship between the dated areas of the trench and this corner because there is a large WW1 test latrine pit isolating it on one side, it goes into our trench edges on two more, and finally it backs onto a higher portion of bedrock on the last. Finally towards the end of the week a stone linear feature was seen in the section of the beamslot and so work began to investigate it, which led to us reaching bedrock around 0.35m below our current level. This could give an explanation for why this area was occupied before the areas with lower bedrock levels, however more investigation is needed before we rule out any other theories.

 

 

Experimental Brewing Summary and Student Reflections

In a follow-up to our earlier blog on prehistoric brewing, these videos record a summary of the process from Becky Brummet, Experimental Programme Director:

As well as comments and reactions from two of our students who were there on the day:

An Excerpt from the Promontory – Bradford Kaims

Trench 12, 13 & 42 were opened (reopened, in T42’s case) this season for sampling & investigations into the burnt mounds located on the promontory.

T12 is a 2m x 3m trench located on the southern end of the promontory. Shortly after opening the trench, we began to find some really interesting artefacts. In the peat layer, we found a piece of burnt quartz & when we continued down through the peat onto the burnt mound layer, we found more: two pieces of worked flint & two pieces of burnt bone! Quite exciting finds for a trench originally opened up for sampling.

 

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A piece of worked flint from trench 12.

 

Trench 13 is 1m x 2m trench located just off the edge of the promontory, near the waters edge. Like T12, it was opened for sampling & has also produced some really interesting finds! Just below our peat layer, we discovered a layer which consists of shells & sand moulded & formed together. In that layer, we uncovered two pieces of charcoal, nine small (4-10cm sized) pieces of worked wood & one log roughly 1m long. We think the smaller wooden pieces may have been stakes & considering their proximity to the waters edge & the fact that a couple were orientated at a 45° angle, it could indicate fencing.

 

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A piece of worked wood from trench 13.

 

A 2m x 4m portion of trench 42 was reopened for sampling, with the focus being on the burnt mound, the trough & the limestone piece. A 1m x 2m spit was dug out of the north end. We expected the burnt mound material to continue at least a half meter, but we quickly uncovered an interesting mottled orange clay layer only 4-5cm into the burnt mound layer.

 

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The re-opening of trench 42.

 

Since the weather has turned more amiable for excavations to continue in our other trenches, we have taken a break from our work on the promontory, but plan on returning to it to as soon as feasible.

Bamburgh Castle, Trench One Update.

Welcome to this Trench One update!

Test pit A (as mentioned in the week 1 interview video) has now been set up and we’ll keep you posted as progress continues.

 

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Test Pit A extending north-south across the width of Trench One.

 

We found the construction cut for the 12th/13th Century curtain wall and it contained a number of pottery sherds, mostly green glaze. It was also the source of the ‘mystery’ clay circular objects which we tweeted last week. One possible explanation of them was bungs scored into unfired ceramics which then popped out during the firing process.

 

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Unidentified clay objects. Any thoughts?

 

Underneath the rubble foundation of the curtain wall we have an earlier (possibly 8th/9th Century) masonry block with adhered mortar associated with two others, which may have been used as the  backing corner of the kiln.

Last week in Trench One the kiln was sampled as planned. It looks like it was damaged and/or broken with use quickly discontinued – there is grain still in situ in large quantities, and the upper fill layer appears to be a ‘demolition’ context with extensive CBM fragments from the body of the kiln. In the video below Sam Serrano, Trench 1 Assistant Supervisor discusses the kiln and its excavation in more detail.

 

Work has also continued excavating half-sections in various small features, post-holes and pits to help add to the stratigraphic sequence and story of Trench One.

 

Introduction to Environmental Processing

In this video Thomas Fox, Environmental Assistant Supervisor, discusses the process of environmental sampling and what we can learn from it.

 

Stay tuned for further videos and updates here and on our YouTube Channel as the season progresses!

Another week in the Finds Department

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The Windmill during a brief respite from the rain.

Good morning from the post-excavation department! We have had a busy few weeks processing some intriguing finds including a possible iron stylus, a worked stone bead, several bits of unidentified burnt clay discs, and a potential lead pendant, to name a few.

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Finds Illustration

Environmental supervisor Thomas Fox has kept our students engaged at the flot tank processing environmental samples from last year while Post-ex supervisor Jeff Aldrich has been taking advantage of the poor weather to give students the a chance to illustrate and process our finds.

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Students Katie and Kelly sorting environmental flotation samples.

The students have also had the opportunity to learn a bit of post-excavation from Bradford Kaims processing finds, including a plethora of worked wooden stakes and the resultant paperwork led by trench supervisor Becky Brummet. Because of its distance from civilisation, it is a separate process at each site: the Castle and the Kaims.

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Students Joe and Rachel filling out timber recording sheets.

With the sun shining and the winds calmer, the students and staff will have ample time in the trenches to find us some new artefacts, hopefully further fleshing out the story of Bamburgh Castle.