Portable Antiquities Scheme blogs

Wonderful, wonderful Copenhagen!

Things have been very quiet on the Piercebridge front recently, as I’ve been grappling with a chapter on the function of coinage in Roman Britain and more than 2600 coins from Old Winteringham in Lincolnshire!

However, things will soon get back on track with regards to Piercebridge as I’m off to Copenhagen tomorrow to give a lecture at the Roman Military Equipment conference. Entitled ‘Is the Piercebridge assemblage a military votive deposit?’, I’m hoping the paper will lead to lots of interesting discussion and hopefully, I’ll get identifications for some of the objects which have proved difficult to pin down.

Anyway, here’s the abstract for my lecture:

Is the Piercebridge assemblage a military votive deposit?

Over the past twenty years, an assemblage of approximately 4,000 Roman objects has been recovered from the bed of the River Tees at Piercebridge, County Durham. The assemblages includes a diverse range of material from jewellery to military artefacts, coinage to medical instruments. Although found directly adjacent to a late third century Roman fort and small town, these objects do not appear to represent settlement detritrus. Rather, they form a large and votive deposit, unparalleled even by the Sacred Spring at Bath and Coventina’s Well in Northumberland. This paper will provide an update on current work on the assemblage and assess the contribution that it will make to our understanding of Roman Piercebridge and of religious practice at the periphery of the Roman Empire. I will concentrate particularly on the role of the military equipment found within the assemblage. Can this equipment be interpreted as representing the offerings of soldiers passing through Piercebridge on their way to the northern frontier or could there be more complex meanings behind the selection and deposition of the material?

I will report back in a couple of weeks time!

More donated treasure finds

Here are two more recent finds reported under the Treasure Act which were able to be acquired by museums after the finders and landowners kindly waived their right to a reward.

Roman silver brooch
This beautiful brooch frame (2012 T640; GLO-734991) was found in September 2012 in Chedworth, Gloucestershire. You can still make out the fine dot decoration on the top of the body. We are very lucky that the finder, Mr Finch, and the landowner, Mr Axford, decided to forego their rewards in order that the brooch could go in to the collection of the award-winning Corinium Museum in Cirencester for all to enjoy.

Anglo-Saxon gold pendant
This little jewellery item (2012 T163; KENT-604B63) has sadly suffered a bit of damage over the course of the millenium it spent in the ground, but it is still easy to appreciate how beautiful it would have appeared when originally worn in the 7th Century. It is a fairly common example of its

type, but it certainly would have belonged to someone with resources! Found in Sturry, Kent, the landowner, who wishes to remain anonymous, and the finder, Mr Hogwood, graciously decided to waive their rewards, allowing Canterbury Heritage Museum to acquire the pendant at no expense.

Conservation Cleaning

To reveal important surface information (as described in the previous blog post), the coins have to be cleaned of surface dirt and corrosion products. This is done using a combination of two treatments; chemical and mechanical cleaning.

The photograph above demonstrates a typical example of the Frome coins once they have had an initial rinse in tap water and brush to remove surface dirt. The majority of coins in this photograph are covered in corrosion products rendering them illegible. These coins would first be treated chemically to reduce the majority of the corrosion products.

Chemical Cleaning

Two different chemical treatments are employed to clean the coins depending on the extent and type of corrosion present. After an initial visual assessment the conservator they will make a decision as to which chemical treatment is required. This is usually a treatment consisting of either a low percentage of formic acid, or an Alkaline solution, or both.

Chemical cleaning allows for large batches of coins to be cleaned at once, which is critical when cleaning such a large hoard. The conservator carefully monitors changes in the coins appearance and condition during chemical cleaning to ensure that the coins are not ‘over cleaned’. All coins which have been chemically cleaned are thoroughly rinsed with water to remove any traces of chemicals.

Coins in Alkaline Rochelle solution. This helps to reduce the level of blue/green copper carbonates.

Mechanical Cleaning

Mechanical cleaning is required when coins have small patches of corrosion obscuring important details. Coins with low levels of corrosion may not need chemical treatment, but will most likely require some mechanical cleaning. All coins which have been chemically cleaned require some form of mechanical cleaning.

Production line of Dremel rotary brushing.

Mechanical cleaning involves reducing corrosion products with a scalpel under magnification and brushing to remove surface corrosion product residue. The photo above shows a production line of conservators using natural fibre dental brushes, on rotary Dremels® . This allows for a greater quantity of coins to be brushed at one time, and is more efficient than brushing them by hand.

Following chemical cleaning corrosion and dirt residues remain on the coin. This coin has been brushed on one half to demonstrate the difference in legibility before and after.

Corrosion

This coin demonstrates the large red/purple crystals of cuprite on the lower half and green copper carbonate corrosion products on the upper half.

The amount of corrosion on the coins varied depending on where they were excavated from in the ceramic vessel. The diagram below shows a cross section of the vessel and the context layers as they were excavated. The annotations below describe the changes identified.

Image courtesy of Somerset Heritage Service Archaeology

Top- Layers 10-13- Coins are well preserved. Corrosion is minimal, dusty and easy to remove.

Middle- Layers 14- 17- The corrosion is very hard making the coins difficult and time consuming to clean. Coins display both green carbonates and cuprite corrosion.

Bottom- Layers 18-19- These coins respond to treatment more readily than the middle layers, however they are not as well preserved as those from the top layers.

The coins from the Frome Hoard were excavated from an agricultural site. Since its burial it is likely that the effects of a fluctuating water table have influenced how the coins have corroded. As the water level rose it caused the bottom of the pot to become more saturated than the top. The ceramic vessel in which the coins were contained would have caused any trapped water to drain slowly. The corrosion pattern noted allowed conservators to anticipate how difficult some coins may be to clean therefore influencing which treatments would be selected.

Recent Donations

A find from the mud…
Mudlark John Higginbotham discovered this interesting Post-Medieval silver toilet implement (LON-F6F381) on the foreshore of the

Toilet implement set from the Thames Foreshore

River Thames. The individual elements of the tool, which could have been used in various aspects of personal hygiene and the application of cosmetics, overlap with one another to form a three-dimensional female figure. There are not many exact parallels recorded, although examples of the individual elements are known. The preservation of this complete set makes it all the more interesting.

Only those people with a license from the Port of London Authority (PLA) are allowed to search with metal detectors on the Thames foreshore and to disturb the ground. All others should restrict their activities to searching with their eyes alone!

John and the owner of the foreshore, the Crown Estate, agreed to waive their right to a reward for this item so that it could be placed in the Tower of London at no expense. Thank you both!

Silver cuff link showcasing a royal occasion
This single silver cuff link (SUSS-5904A7) was found by Tyndall Jones in Warningcamp, West Sussex. It would have originally been joined by a metal link to a matching cuff link which would have enabled them to hold together two pieces of fabric. Cuff links with this design ‘Crown over two hearts’ are likely to be associated with a commemoration of the marriage of Charles II to Catharine of Braganza in 1662.

Silver cufflink from Warningcamp, West Sussex

You may have seen the Portable Antiquities Scheme’s Dr Michael Lewis talking about a similar cufflink in the collection of the British Museum on the ITV series Britain’s Secret Treasures. Michael has been researching these items and has noted that finders have reported almost 90 cuff links of this type since the start of the Treasure Act in 1997. Before then, there weren’t any records of these items at all!

Both Tyndall and the owner of the land, Nigel Draffan, waived their right to a reward for this piece of Treasure in order that it could be acquired by the nearby Littlehampton Museum. Many thanks Tyndall and Nigel!

Donations

An Early Medieval silver-gilt disc brooch, now in the care of the Isle of Wight Heritage Service. Both the finder and landowners waived their right to a reward in this case (ref. IOW-A33D42)

Finds reported under the Treasure Act and recorded with the Portable Antiquities Scheme are occasionally acquired by museums at reduced or no cost, thanks to the generosity of finders and landowners. It is fitting to highlight these finds and to thank those individuals who have foregone a financial reward in order to see the finds in a museum collection where they can be studied and enjoyed by all. Each year, almost 10% of finds reported as potential Treasure are donated to museums, which is a great statistic. We’ll be trying to keep this blog updated periodically with recent donations as they are made.

How are donations made?
Finds which meet the criteria for ‘Treasure’ under the Treasure Act may be claimed by the Crown and placed in an appropriate museum. That museum is required to pay a reward to the finder and landowner equal to the market value of the find, but the finder and landowner can elect to waive their reward, thus enabling the museum to acquire the find without resorting to public expense. We refer to these acts as ‘donations’.

Most of the finds recorded with the Portable Antiquities Scheme are not Treasure, but a museum may nonetheless be interested in acquiring them. A Finds Liaison Officer or National Finds Advisor may recognise an item’s significance and speak to a museum curator about the item; if the museum curator wishes to acquire the find, they can be put in touch with the finder/landowner. The finder/landowner may then choose to donate the find to the museum if they wish.

Private collections
Many finders have built up their collections of archaeological finds over the years, and it is worth thinking about a long-term home for this material when the owner passes on. Museums may be willing to accept the material as a donation and it is advisable to discuss this possibility when the opportunity arises – before it’s too late!

Questions?
If you have any questions about donations, or if you are considering donating your find, speak to your local Finds Liaison Officer or the Treasure Team at the British Museum (treasure@britishmuseum.org).

Investigating the lead rolls – curse tablets or fishing weights?

One of the more intriguing features of the assemblage is the large number of sheets of rolled lead. At present, we’ve catalogued more than 130. It’s tempting to interpret these objects as lead curse tablets, which are a feature of many Romano-British religious sites, such as Bath and Uley. Take a look at the ‘Curse Tablets of Roman Britain’ website for more information: http://curses.csad.ox.ac.uk/

A curse tablet or a fishing weight?

It would certainly be extremely significant if they were inscribed, but until some of them are unrolled we can’t be certain about their function. Unfortunately, it’s quite an expensive process to do this, so we’ve invited Stephanie Vasiliou, an MSc student in Conservation for Archaeology and Museums, at the Institute of Archaeology at UCL, to do a non-invasive study of the assemblage to try and learn more about them.

Stephanie has this to say about her study:

”I became involved with the Piercebridge Project in February of this year, when I opted to use a group of 130 pieces of rolled lead as the basis of my material science project. I am carrying out a technical study of the material, analysing weights, dimensions and composition, with the hope of identifying what these intriguing little pieces of lead where – curse tablets? Fishing weights? Scrap metal? All three? None at all?

I will be using a nifty portable X-ray fluorescence machine to initially analyse the material, but as the project develops, it may mean that more in depth methods of scientific analysis are needed – especially if I move on to unrolling and conserving the material, which as a conservation student is a pretty exciting – and daunting – prospect! “

Another smaller lead roll? Just scrap or something more significant?

Fingers-crossed they turn out to be curse tablets!

Stephanie, posing with a famous iron structure (no lead in sight!)

A word from one of our divers, Rolfe Mitchinson

A Samian ware vessel in situ on the riverbed

As the finders of the Piercebridge assemblage, Bob and Rolfe are integral to the project. Here, Rolfe tells us how they made their important discovery:

“Hi, I’m Rolfe, one of the Piercebridge Divers, and I have been asked by Philippa to write a few lines for the new Piercebridge Project blog. The other diver is Bob, who has been my diving, fishing, golfing, hiking and ‘Real Ale’ buddy for the last 37 years

Bob and I met at our local scuba diving club in 1975. We were quite happy sea diving, looking for shipwrecks, when we were introduced to a local archaeologist named Raymond Selkirk, author of ‘The Piercebridge Formula’ Ray asked us for help, by searching rivers for roman bridge crossings.

Our first find in 1984, was in the River Tyne at Corbridge where we discovered an ancient mysterious 24ft square stone and timber platform. From then on, we were hooked on archaeology, and made some great discoveries in our northern rivers.

In 1987, Ray asked us to look for the Roman bridge at Piercebridge. The timber remains were last seen in the severe drought of 1933. Ray’s location was spot on and we were soon looking down in 4ft of water at the massive timber beams and wooden piles of our first Roman bridge. The bridge timbers were carbon dated in 2009. This was funded by Time Team and the Durham Archaeology Section at Durham County Council and produced some amazing results. The raft beam was felled in AD 129 and the upright pile 2 metres away in AD 253. This suggests that there were either two consecutive bridges, or that one had been repaired.

We noticed Roman pottery protruding out the riverbed which consisted of hard packed stones, silt, and mud. Whilst wafting the silt, our first coin appeared. It was a denarius of Vespasian. That first dive produced 6 Roman coins plus a selection of artefacts which included needles, a lead seal, a copper alloy statue, 3 leather shoes, a finger ring and a gold earring.

Over the next 25 years we have uncovered and plotted more of the bridge remains, and in the process recovered thousands of coins and artefacts.

In 1998, while searching further up the river we uncovered an earlier bridge, which produced a small collection of coins and artefacts This unknown bridge was showcased by Time Team in 2009, and carbon dated between 15-75 AD, so maybe it was in use by the Brigantian Tribe before the Romans officially arrived.

Britain has many rivers, which means that many lost Roman bridges are waiting to be discovered. All that is needed is a healthy respect for the river, scuba diving skills, and stacks of enthusiasm. However, Bob and I urge all river divers to report any finds and associated information to their County Archaeologist and the Portable Antiquities Scheme, so that more pieces can be added to the jigsaw of Britain’s history.

Our thanks to Philippa for her brilliant work on the collection, aided and abetted by Frances and the rest of the team. We look forward to seeing how the project progresses and finding out the secrets of the objects we have recovered.

Bob and I are long standing members of The Northern Archaeology Group”

A very pointy leather shoe complete with hobnails found on the riverbed.

Dr James Gerrard joins the team

Frances opens a box of pottery we haven’t seen before!

On Friday, despite the freezing weather, Frances McIntosh, Dr James Gerrard and myself went out to Rolfe’s house to look at the Piercebridge pottery assemblage. The task for the day was to persuade James (a lecturer in Roman archaeology at Newcastle University and a pottery expert) to be our pottery specialist and to devise a strategy for the study of all 50 kilos of pot from the site. Fortified by a continuous stream of sausage rolls and cups of tea (thanks, Rolfe!) we managed to achieve both.

Here’s what James has to say about the assemblage:

“I had an email from Philippa a few weeks back asking whether I and the Centre for Interdisciplinary Artefact Studies at Newcastle University might be interested in working on the Piercebridge pottery. So today we went to meet Bob and Rolfe and I had a good look at the boxes of pottery.

It was a pretty interesting collection. The first impression is that it’s all pretty fresh with sharp edges and breaks. This is important because it should indicate that the pottery hasn’t travelled far in the river.

Some of the decorated Samian from Piercebridge

There’s a small but important collection of samian from Gaul, which includes some decorated vessels and sherds with makers’ stamps. There was even a piece with a rivet hole – this shows that it was repaired in antiquity and is an indicator of the esteem that samian was held in by the Romans.

There are a few sherds from large olive oil amphorae from Spain and quite a few beakers and drinking vessels. Some of these are from the Nene Valley and include vessels decorated with hunting scenes.

Most of the pottery are black and grey kitchen and tablewares. Jars, bowls and dishes are present and the vessels range in date from the second until the fourth century. Some of the latest sherds are from BB1 jars and bowls. It was nice to see these because they come from Dorset and I wrote my PhD on this type of pottery!

James explains the dating of Black Burnished ware to Bob

It’s early days and the next step is to get the pottery up to Newcastle so I can study it properly. That said, one striking aspect of this pottery is the lack of any flagons (jugs). I’m not sure how to explain this but it’s a hint that these boxes of pottery have secrets to reveal.”

James, Philippa, Bob and Rolfe on pottery sorting duty

Meet the team: Becky Dobson

The ever-cheerful Becky!

Becky is another of my trusty volunteers. An undergraduate at Kings College London, she is interested in all things Roman and is currently writing her dissertation on the Piercebridge assemblage. Since January, she’s been helping me create a skeleton catalogue of every object in the assemblage and is always cheerful, even after helping catalogue hundreds of copper-alloy rings, studs and tacks day after day after day!

She has this to say about working on the assemblage:

“I started working on the Piercebridge assemblage last year as part of a summer work experience placement at the British Museum. I was responsible for weighing and measuring all the coins and checking that each had a PAS database record. Although this work was quite repetitive, it’s meant that I know far more about Roman coinage than I did before! I’m particularly interested in the cut, rolled and mutilated coins which may have been ‘ritually killed’ before being thrown in the river. I like the idea that even everyday, functional items could be transformed into items with ritual significance with religion pervading all aspects of life.”