THE INVESTIGATION & CONSERVATION OF ROMAN ARTEFACTS
FROM A FARMER’S FIELD IN KENT

AKA: ‘PLOUGHING DEEP:
THE MYSTERY OF A BOX, JUG, BOWLS & AN AMPHORA’

Chance Finds Exhibition, Canterbury Museum

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A group of Roman copper alloy vessels, ceramic and wooden fragments were brought to AMTeC by Dr. Andrew Richardson, Kent Finds Liaison Officer for the Portable Antiquities Scheme (www.finds.org.uk). Some of the finds were metal detected from plough soil, others were recovered from a trial excavation of the area near the find spot containing a large metaldetected bronze jug.

Although the finds were of incomplete, fragmented and mis-shapened pieces – close examination has uncovered much information about their original forms and possible relationships to each other.
A number of different scientific techniques have been applied to the material towards the quest of understanding the assemblage:

Microscopy:

Identification of wood structure preserved by mineral salts of corroding iron fittings – this confirmed that there had once been some type of wooden container/box/casket – which probably contained cremated bones. Other cremation burials with wooden boxes found from Roman Brittain had feasting vessels surrounding the box.

Fine striations on the metal surface of the best preserved fragments of a bronze bowl may explain how it was made and why it has survived with such a beautiful patina.

X-radiography:

X-rays penetrate metal in relation to what it is made of (components of the alloy eg. different %s of copper tin and lead), its thickness, how it was worked, and corrosion effects. These differences in penetration will expose the x-ray film to different degrees of light and dark. This was a useful tool for knowing which fragments of metal went with which vessel. They also help guide the conservator when cleaning heavily corroded metal such as the iron fittings associated with the wooden box.

Metal vessels are usually shaped by ‘raising’ – hammering to shape over curved anvils, starting from a flat sheet of metal and hammering in even concentric lines until the desired shape is achieved. Rows of hammer marks can be seen on many of the x-rayed fragments – this allowed us to be sure that we were orienting pieces of the jigsaw in the correct direction when we were looking for joining fragments

X-ray Flourescence:

XRF is a non-destructive analytical techniques which was used to identify the specific metal alloys, enamel, and mystery ‘white lining/residue’. This is a surface technique, and therefore only gives us a general understanding about the materials used – corrosion effects may cause different concentrations of alloy components to appear at the surface than when first made. XRF analysis was undertaken by David Dungworth at the English Heritage Ancient Monuments Laboratory, Portsmouth. The copper alloy bowls appear to all be made of a similar bronze alloy – yet they have different surface corrosion colourations – perhaps this is due to the different methods of manufacture and uses the bowls were put to.

Soil Sample Sorting:

Children attending ‘Archaeological Detectives’ courses at AMTeC for Medway Council’s Children’s University have sorted the various material found in the soil excavated from the amphora and the plough disturbed pit containing the wooden box. They discovered fragments of a decorated glass vessel, charcoal and cremated bone, a tooth, more metal vessel pieces and fragments of iron. Trevor Anderson, an archeo-osteologist tutored the children and identified the bone and tooth remains – he said there wasn’t enough cremated material to have come from one burial: it is likely to have been dragged into the amphora by a plough… perhaps what was found in the amphora had once been associated with the wooden container and rich metal vessels?

Experimental Archaeology:

The striated lines, beautiful patina, and smooth density of the large bowl on display point to it having been manufactured or at least burnished on a lathe. A central dimple in the base also indicates that it has been on a lathe. A local silver smith, Ray Walton, demonstrated the technique – the spun object was then examined by microscope and X-radiography for comparison to the ancient finds.

The scientific analysis of this exciting burial group is still ongoing… results will be posted as they come in:

• XRD (X-ray Diffraction):
  Ian Slipper and David Wray at the Earth Sciences Dept. of Greenwich University, Chatham are looking at the specific crystal structure of the mysterious white deposits which seem to line the inside of one of the bronze vessels. Perhaps this is limescale, and the bowl had been used repeatedly for boiling water – sample of modern limescale will be analysed in comparison.
  
  
• Jacqui Watson at the English Heritage Ancient Monuments Laboratory, Portsmouth is studying the minerally preserved wood to try and further identify the type of wooden box. She is also examining the fragments of decayed wood found near the jug to try and determine if they are staves from a wooden bucket.
  
  
• Organic Residue analysis will be carried out on samples taken from the amphora and metal bowl with mysterious white deposits, in hopes of identifying what these containers might have contained.

AMTeC CHATHAM FOUNDRY USED AS ANCIENT TECHNOLOGY FILM LOCATION

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AMTeC DIRECTOR AWARD

AMTeC Director, Dana Goodburn-Brown has been awarded Lifetime membership of the Millennium Awards Fellowship following completion of her project “Old Objects – New Visions”.

She was awarded £10,000 by The Royal Society & British Association for the Advancement of Science to develop an interactive science display involving experimental archaeology and children in the Medway area.
The video microscope purchased with this grant has also been widely used at museum demonstrations and on location for television programmes over the past 6 years.

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