This month (October 2015) I had the great adventure of doing some bronze casting with Il Tre de Spade (The Three of Swords) at the Archaeological Park and Open-Air Museum of the Terramare in Montale. The museum is located just south of Modena and recreates Bronze Age houses surrounded by a palisade and a marsh, appearing as it would have in the central and later phases of the Bronze Age there (1600-1250 BC). The museum hosts demonstrations and activities, along with a recreation of the original excavation.
The houses are nicely furnished, with well laid out areas for cooking, sleeping, food storage, and workshops. One house has a workbench for wood and antler working, along with weaving and other crafts. The other has a metalworking workbench with stone anvils, moulds, bellows, and all the needed kit stored neatly on shelves and a work bench. Unlike the recreated roundhouses that are often seen in the UK, you can get a good idea about how the ancient people lived here and where they put their all the things they used in every day life.
(Click on the thumbnails here to see a larger version)
I had been invited to join the casting demonstrations by Claude Cavazzuti, who is also part of EXARC. He is one of Il Tre di Spade (along with Pelle and Scacco) , who were some of the first metalworkers at the museum after it opened several years ago. They do regular demonstrations (sometimes with hundreds of visitors per day) and also run workshops that introduce people to Bronze Age casting and metalworking with a focus on the Middle and Recent Bronze Age (1700-1150 BC) of Northern Italy.
The furnaces there are small clay-lined trenches about 25 cm deep and 50 cm long, something that would be nearly invisible archaeologically and easily interpreted as a cooking hearth (and really, there’s no reason why they couldn’t be both). The furnaces heat up quickly and work efficiently. The charcoal is concentrated around the crucible with more warming beside it so that the fuel is hot before it gets raked around to cover the crucible.
My first new introduction was the bag bellows. They were larger than I have used in the past, and made of heavier leather. They put out an enormous volume of air, but also their size allows the person pumping the bellows to sit on a low stool. One nice innovation is that they put a large stone in the bottom of each bag. That prevents people who are new to bellowing from lifting them too high and causing the bags to collapse.
The real challenge for me was the valve and the way the bellows open at the top. The bag bellows I’d used before have straight sticks in the handles that either open parallel to each other, or are hinged at the back to open like a “V”. These bellows have two sticks on both sides, so that they open into a diamond shape with the wide part opening where your hands hold the bellows. It took a little bit to get used to them and to figure out where best to position my fingers. I never did get it quite tight enough and could feel a bit of air blasting on the back of my arms, but they still delivered a powerful amount of air. The tuyere was a large clay tube that curved downwards at a 90° angle, and was positioned so that it was directly above the crucible. This mean that the charcoal had to be moved frequently to keep the crucible covered. Without the layer of charcoal above, the air coming from the bellows would cool the metal in the crucible.
The crucibles are a flattened dish-shape, with some that were larger and a bit more of a bowl shape to hold more metal. They have a tab on one side that is used as a handle. The crucibles have a small lip for pouring that causes the metal to pour more quickly and flow out in an arc, rather than almost straight down like the triangular bag-shaped bellows used in Britain. It took a little bit of getting used to the trajectory of the metal in order to get all the metal in the pouring cups.
The tongs they use are beautifully crafted from wood and cord. They are kept in a bucket of water to keep them from burning when holding the heated crucible. The entire organisation of tools and materials is efficient and elegant, and there is nothing that would not have been found archaeologically from this period.
For the first demonstration a sword was cast into a sand mould. The sand they use is local, and perfect for casting. Commercial casting sand consists of fine sand and dry bentonite clay. The sand from the Po River delta is exactly that, sand that has been reduced to almost a powder by erosion, combined with clay and silt that has been washed into the river. The Po River sand leaves a much finer texture on the finished objects than the coarser commercial sand that I have used here. Looking at the quality of the sand, I could imagine how different sands might affect the regional quality of casting, and might even have had value as a commodity.
The mould for the sword was made using the standard cope and drag method, with the pouring cup on the side of the sword, rather than pouring from the top. A large vent was also placed at the tip of the sword. The mould was placed at an angle. As the crowd gathered and settled onto benches under a marquee, Claude explained Bronze Age metalworking techniques and then the sword was cast. Everyone was impressed and even more so when the sword was taken from the mould.
After the demonstration was done we started up a second furnace for the workshop. For this one we used the stone moulds that were on display in the house. The moulds were made of a very fine grained local stone, the same that had been used by the Terramare circa 3500 years ago. The moulds were warmed next to the furnace and then strapped together with leather strips. We took turns bellowing and pouring. The shallow crucibles mean that the pouring has to be done more quickly than with deeper crucibles. They cool quickly, so there is little time for dragging out charcoal and skimming. Once the metal was molten, we gave it a quick stir with a stick, pulled the crucible out with the wet tongs, and poured the bronze into the mould while holding the stick across the top to keep the charcoal back.
Sickles, knives, and daggers were cast. Later we moved on to using sand moulds. I borrowed one of the antler spindle whorls from the woodcarving house to see if I could try casting that as an experiment. It worked sort-of. It will take a bit of work to get finished up, but I think with a couple more tries we could have got it spot-on.
I was wearing my bronze torc bracelet that day and one of the new people wanted to try casting that. We used it as a model for a sand mould and after a couple tries, we got a cast that made a perfect duplicate.
While we were casting, more tour and school groups came through to watch more casting demonstrations. School kids also had the opportunity to make their own copper bracelets. There was a square of tables set up with small stone anvils and hammerstones. Punches and chisels were available so they could decorate the strips of copper to make bracelets in patterns that would not have looked out of place in a Terramare village.
Often after the casting is done for demonstrations the bronzes are taken home and finished up using drills and angle grinders, but not here. We had a relaxing time using wet sand on the hard, fine-grained anvil stones to grind off the flashing and excess metal. Some smaller stones that had a coarser texture could be held in the hand and used for working the inside curves and corners. I’d brought my small socketed hammer along and we used that to break off some of the metal, too. Between light hammering and patient grinding, the daggers were smoothed rather more quickly than I would have expected.
It was a great day, and one that was full of new experiences. It was particularly interesting to see how much variation there is in doing the same tasks and getting successful results. The different types of bellows and crucibles make for differences in how tasks are performed. Other small acts show variation between different metalworking groups. Tasks such as turning the crucible over to remove dross and leftover metal after casting was done into the furnace here, where in Ireland we have always done that next to the furnace. These are small things that could be seen archaeologically if excavation is done carefully, but also shows how customs and metalworking traditions develop with regional differences.
Next month I will be moving to Modena and will be in the vicinity of the park. I hope to do more casting there and to learn more about the Early Bronze Age metallurgy of Northern Italy.
A special thanks to Il Tre di Spade, Claude, Pelle, and Scacco and the staff at the Parco archaologico e Muse all’aperto della Terramare for inviting me to participate in casting. I would also like to acknowledge Markus Binggeli & Markus Binggeli who are masters of bronze casting and replicating ancient metalworking techniques. They are mentors of Il Tre di Spade, and provide both inspiration and technical expertise for experimental archaeologists.
If you’d like to learn more about the Early Bronze Age in the Modena area, the work of Il Tre di Spade, and the Terramare Open Air Museum in Montale you can find links below.
Italian language sites
English language sites
Il Tre di Spade also have a Facebook page.
I finally got the fibulae I cast in Dublin last month finished and fitted with pins. They polished up nicely and look a lot more shiny than their counterparts in museums. I still have a hammer and a couple other castings to clean up. Meanwhile a new batch of waxes are in moulds and if the weather behaves they could get cast up in the next couple weeks.
There’s even a slow motion film of one of these guys being cast thanks to the folks at UCD.
17-18 January 2015
I missed the first day of the conference, choosing instead to go to my PhD graduation ceremony. It was a wild trip. I graduated with the full regalia of cap and gown, had a quick couple glasses of wine at the archaeology department’s reception, and then we hopped on a fast flight to Dublin for the EAC9 conference at University College, Dublin. The conference was a collaborative effort brought together by EXARC, UCD, and the Irish National Heritage Park. It was a large conference with over 200 delegates, 20 papers, and 31 posters.
The Dublin University campus is huge and spread out, so we had a time trying to find the right building. I arrived just in time to deliver my paper and see the rest of the session. There were some interesting papers and posters given that explored the range of pyrotechnology in archaeology from cremation to glassworking and metalwork. In addition to the usual poster session, individual posters were given a ten minute presentation while being projected in the main hall. These included Jiří Hošek, Ryszard Kaźmierczak, Paweł Kucypera & Maciej Tomaszczyk (Nicolaus Copernicus University) with a presentation on steel carburising in a small shaft furnace, and Yuri Godino & Lorenzo Teppati Losè (University of Florence) presented a poster on their experiments on cupellating galena to produce refined silver.
I was also interested in the presentations on glassworking. There were two very different approaches to the subject with Marta Krzyżanowska & Mateusz Frankiewicz from Poland who spoke about producing Early Medieval lampwork type beads in an open hearth based on excavations in Ribe. Jonathan Thornton from Buffalo, New York spoke about replicating trade bead production based on evidence from Africa using glass frit in a clay mould .
The presentations that discussed metal began with my presentation on inverse segregation and its influence on chemical analysis of objects cast in the Bronze Age. Padraig McGoran of Umha Aois presented a poster on his experiments that included problems and solutions in casting into open one piece moulds.
After that I was off to the university’s experimental grounds to help set up furnaces and get ready for casting. The centre boasts a Mesolithic house, along with metalworking furnaces in varying states of decay. There are separate areas set aside for flint knapping, firing pottery, and active metalworking projects. The members of Umha Aois had already started building a variety of furnaces that included ones heated from below, from the side, and another with a tuyere that had a 90 degree bend that blew the air directly onto charcoal covering a flat, pan-shaped crucible. I worked at a portable ceramic furnace that was brought to the site by Fiona Coffey. It was set up inside Billy Mag Floinn’s newly constructed traveller’s tent. Despite it being wind and waterproof, the flaps ventilated it well and we kept warmer than the others who were set up under a tarp outside.
At lunch I was presented with a birthday cake. Unusual as it was no one had anything bigger to cut it with than a pocket knife. The only solution was to get one of Billy’s bronze swords and carefully slice it. It was a most memorable birthday.
Finished projects were on display, including swords, horns, tools, spears, and stone moulds. We spent the day casting axes, jewellery, tools, and other objects. There was a constant flood of visitors and regular announcements were made when one of us was ready to pour. For most of the day it was standing room only. The casting events continued all afternoon and into the evening.
Slow motion film of me casting some little bronze fibulae
Rather than head straight back to Sheffield the next day, I had arranged to see the Bishopsland Hoard and a hammer from the Garden Hill Hoard at the National Museum. I’d hoped that I could see some moulds, and to have some colleagues also examine the objects. Unfortunately emails were crossed and I just got to see the hoard and hammer. However, that was fascinating in itself, and I spent hours measuring, weighing, drawing, and photographing every detail of the artefacts.
Events like this are exhilarating and exhausting. We all learn more every time we meet, and we come away with new ideas as well as newly cast objects to finish up. This week I’ve been filing and polishing some of the bronze fibulae I cast and I still need to get to work on the replica I cast of the hammer from the Lusmagh Hoard. Meanwhile, there are more waxes and moulds to make to get ready for casting again.
Click on the link for more information about the conference EXARC: 9th Experimental Archaeology Conference, Dublin (IE)
and here is a moment by moment twitter feed from the conference
Here are some useful links to academic journals on archaeology. I’ll do my best to make sure the links are current.
Many of the journals linked here are open access, but many aren’t. If you need to access an article, many public libraries do have free access to journals, in addition many universities in the US often allow public access to their libraries. Another resource is to check academia.edu. The site provides open access to articles, theses, dissertations, and conference proceedings.
Note that this is by no means an exhaustive list of the journals out there!
Assemblage – The Sheffield Graduate Journal of Archaeology (OPEN ACCESS!)
Berkshire Archaeological Journal (OPEN ACCESS!) Note that the journal runs from 1878 to 1980
British Archaeology (OPEN ACCESS!)
CBA Research Reports (OPEN ACCESS!)
Discovery and Excavation in Scotland (OPEN ACCESS!)
Journal of Archaeology of Northwest Europe (OPEN ACCESS!)
Journal of Conservation & Museum Studies (OPEN ACCESS!)
Journal of Open Archaeology Data (OPEN ACCESS!)
London Archaeologist (OPEN ACCESS!)
Open Access Archaeology Journals (OPEN ACCESS!)
Papers from the Institute of Archaeology (OPEN ACCESS!)
PAST (OPEN ACCESS!)
The Post Hole (OPEN ACCESS!)
Proceedings of the Society of Antiquaries of Scotland (OPEN ACCESS!)
Scottish Archaeology Internet reports (OPEN ACCESS!)
Surrey Archaeological Collections (OPEN ACCESS!)
Sussex Archaeological Collections (OPEN ACCESS!)
These are a few of the books I’ve found useful. Again, it is nowhere close to being exhaustive, but I plan to update it regularly.
Note: Clicking on the image will take you to Amazon.com where I get a slight kickback if you buy anything when you visit the site (even if it isn’t the same book you clicked on). Yep, this is blatant monetising, but I don’t have advertising on the site and any source of income helps pay the bills for the site. That said, these are all books and authors that I have in my library and highly recommend.
Books on Craft in General
The Craftsman by Richard Sennett is the book to start with for understanding craft, how it works and how it is learned.
The Search for Structure by Cyril Stanley Smith is a joy to read. He explores structure, art, and craftsmanship from an engineering point of view, but also as one who sees the world as a work of craft.
One of my favourite quotes comes from this book:
I asked a blacksmith famous for his superior penknives to tell me the difference between iron and steel. “What’s the difference?” he replied. “What is the difference between an oak tree and the willow—they have different natures and one must adapt to them.” He did not accept the suggestion that some material absorbed from the fire’s charcoal might have something to do with it, and he would not have understood a word of any lecture I could have given him on diffusion, crystal structure, and phase transformations; yet he could make a good knife and I could not. (Smith, 1981, 348)
Books on the history of metalworking
Ronald Tylecote is probably the author to start with when studying archaeo metallurgy. His work covers the beginning of metallurgy to the Industrial Revolution, exploring the development and changes in technology and experimental work with smelting and furnaces.
A history of metallurgy follows the development of metalworking from ancient Egypt (at the time he wrote, these were the earliest known examples) through Medieval Europe. Despite its age, this is the most comprehensive volume on ancient metalworking and a good start in learning the prehistory of metals.
The following two books are nearly identical. Don’t feel as if you are missing out if you don’t own both. Both are excellent references and the chapters are divided by metals, so all the information about copper is provided together, as is silver, tin, gold, lead, and iron.
Books on experimental archaeology
John Coles is the granddaddy of academic experimental archaeology. He did write the book on it, and back in the 1970’s worked to make it a more organised discipline. These books are excellent introductions to experimental archaeology.
Books on metalworking
Knowing archaeological metals is one thing, but knowing how to work with them, their practical properties, and hands-on experience is essential. These are the books that I feel are essential essential guides for practical metalworking.
Tim McCreight’s books are great bench guides that are well organised for quick reference. They are also great textbooks for metalworking.
Here are some of the wonderful people and groups out there. Some relate to experimental archaeology and others are great resources.
This site wouldn’t exist without the patient help and technical expertise of Ciaran Benson. If you need a web guru, look for him at cicanhelp.com/.
Archaeological Data Service (ADS) A thoroughly useful site. It has a search function that allows keyword searches for archaeological sites and objects. It is also a repository for grey literature (unpublished, privately, or locally published archaeological site reports) in addition to hosting regional archaeological journals and archives.
The Portable Antiquities Scheme has a searchable database of finds throughout England. It also has useful articles on typology and information about conservation and laws regarding finds and treasure in Britain.
Need archaeological supplies? remember when doing experiments, it’s important to record as much as possible. Archaeology Trowels and Tools has almost everything you need from photographic scales to weatherproof notepads and permenent ink pens to keep track of all the details.
Ancient Malt and Ale is a site devoted to recreating ancient beers and ales. I’ve had some of Merryn Dineley’s brews and can truly appreciate her work in experimental archaeology. If you want to know more about brewing in antiquity this is a great site to check out. There’s a Facebook Group, too: Ancient Ale & Beer: recipes, techniques and traditions
EXARC is dedicated to all fields of experimental archaeology. They host annual conferences and a peer reviewed journal, in addition to providing a network to promote open air museums. The journal is available online, and there is a lively Facebook group.
Umha Aois a group of artists and archaeologists dedicated to rediscovering Bronze Age metalsmithing and casting techniques. Their website includes videos, articles about the projects they’ve done. They also have a Facebook page.
Looking for a place to spend an archaeological holiday? Or just wishful thinking about exotic sites? Check out Past Horizon’s Timeless Travels.