Getting into Pottery

Literally. We may have found evidence of crushed human bone being mixed into the clay used to make Early Bronze Age pottery. While I was looking at the Moseley Height Bronze Age pottery last week in Towneley Hall Museum I saw something that I thought was very exciting. Large white specks in the body of the pot had a very bone-like appearance. I kept quiet about this in last week’s post because I hadn’t had chance to check it out properly, however…

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This is the surviving portion of Urn C. It is the bit around the rim and, as you can see, it has been fairly intensively restored since it was excavated in 1950. There are big sections where the shape has been reconstructed (or made up) using plaster of paris and brown paint. The rest of it is original Bronze Age ceramic but, to keep it from crumbling, it has been impregnated with something like PVA resin. Oddly, this means that the whole thing now feels as if it is made of plastic, which I suppose in one sense it is.

What this image also shows are the white specks of whatever it was that had been used to temper the clay. I’ve posted before about the processes of pottery manufacture and the need to add temper to clay. There are various practical reasons why you do this; it lets the steam out during firing and can improve the heat resistance of the finished pot. However, studies of modern potters in traditional societies around the world also show that it is often added for all kinds of other strange reasons. This is not to say that the temper wasn’t regarded as extremely practical by the people who used it – you can see, for example, how putting something into the mix of a burial urn that stopped the spirits of the dead from coming to eat your soul might be a high priority.

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Last week, peering through the layers of resin wIth my little x20 magnification jeweller’s lens, I wasn’t quite sure what these white lumps were. Mike very generously agreed to loan us the pot so I could bring it back to Preston and put it under a microscope. On Wednesday morning Clare and I borrowed the fancy new digital microscope in the Forensic Science lab (usually used by our ballistics people to study gun cartridges) and set about trying to capture good images of the mystery tempering material.

Urn C000001

Here is one of the images from the microscope, clearly showing the bone structure in this particular fragment. Also, just as clearly showing all the shiny plastic of the consolidating resin and the microscopic particles of soil and roots now trapped in there forever.

Urn C000012

This is another fragment at slighter smaller magnification. Jim has had a look at these too and, like me, he is convinced that they are particles of burnt bone.

Burnt bone as temper in British prehistoric pottery is unusual, but not completely unknown. I know of Neolithic sherds from Hazleton North in Gloucestershire and Market Deeping in Lincolnshire, where bone was used in this way, and there are almost certainly others. We now have lots of questions about our bone tempering. Why did this pot need crushed bone in it when the other two urns from the site don’t have any? Is it cremated human bone or is it animal? (we are casting about for a non-destructive way to answer that one) and what is the relationship between the cremated bone buried in the pot and the bone temper fired into the body of the pot? We can begin to imagine all kinds of fascinating connections between the body of the pot, the body of the person buried in the pot, the food they ate and the other people buried in the ring cairn.

Rick

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13 comments
  1. Matt Jones said:

    Hi do you have the full refferances for neolithic pot with bone in

    • Hi Matt

      The Hazleton one is in the pot report within the main site monograph by Alan Saville

      Saville, A 1990. Hazleton North: the excavation of a Neolithic long cairn of the Cotswold-Severn group. London: English Heritage

      The Market Deeping one was a Mildenhall vessel in an assemblage I reported on for Heritage Lincolnshire from a commercial site on the Market Deeping bypass – not sure if it was published or if it was just a client report – it might be on OASIS.

      There were a few more than that from a literature trawl I did at the time, they were all Neolithic – details are on the hard drive of my last computer but one 😦 If I can track it down I’ll post the list up here

      hope that is some help

      Rick

  2. This is a really fascinating discovery! I am intrigued and cant wait to read more about it.

  3. mike said:

    wow awsome

  4. Wow! I wonder if it could be accidental? That clay winnowed from a location that happened to also have cremated bone fragments within the matrix too nominal for the potter to obligate much concern? I am a post 19th century historical archaeologist, so I may be lost on some of the bronze age specifics, but in 19th century and later mining sites you get assaying crucibles made entirely out of crushed, dehydrated bone of unknown reference, presumably an ungulate. It is used because it absorbs impurities more readily than ceramic and can withstand much higher temperatures in a kiln (ca. 1500-1800 F). Just a thought on where I have seen it before in a utilitarian function.

  5. Hi Sean – you do get bone temper used a lot in later periods preceisly because it is so good at high temperatures – bone china is the obvious example – but of course these collared urns were produced in relatively low temperature bonfire firings. The maximum temperature we’ve had in experimental wood fueled fires was around 1100 C (not sure what that is in old money) and usually lower than that. The main reason I think it is deliberate is that these are big chunks – at least 1 mm across usually and there isn’t the range of smaller sizes you would expect if the clay was accidently picking up cremation debris from being processed in the same area.

    Rick

  6. Can you list some articles dealing with ritual or other uses of minerals and other materials in pottery manufacture? It makes obvious sense after reading your post, but I never ever considered the possibility…

    • Hi Carlos – thanks for your comment – I’m going to post about the bone inclusions again later this week so I’ll get some reading up then
      Rick

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