Tuesday, December 16, 2014

Examples of the Importance of Experimental Archaeology

A well-published experiment, in such a way that many people could share in the knowledge and insights learnt from this activity, was the building of a Stone Age house in Denmark in 1958 by Hans-Ole Hansen. He describes the successes and setbacks in an accessible, lively manner. Such activities, based on trial and error, cannot follow a planned script, because many details are unknown from the drawing table. They are more about gaining experiences and counting how much material and how much time goes where (the way `we' build it). The fact is, 50 years later, we still meet surprises each time we build a `prehistoric' house somewhere; surprises that mean we need to improvise and solve problems on the spot. For example, one needs to have tried cutting trees with both a stone axe and a steel axe before you can compare them in usability. It takes some experience in using both kinds, as they need to be handled differently.


Overview over the Iron Age village at Lejre Experimental Centre, Denmark. Picture: Roeland Paardekooper.

Building an Iron Age house in the present day might say little about how it was to build such a house over 2000 years ago, but it is up to experimental archaeologists to find out what we actually can learn from it. By dismissing the human element and measuring the time it costs for someone to reach a goal does not mean that registering time is useless. Some processes have always led to the same results, both in the past and in the present. That is why it is good to measure how much time it takes, for example, for ceramics to be baked at a certain temperature, within the context of the variables, such as the kind of clay and the kind of kiln. 

In the 1950s, knowledge of how to smelt iron without using a modern blast furnace had almost vanished in Europe, although hundreds of archaeological sites were already identified as iron-smelting sites. Without exact knowledge, the evidence of the different stages would be impossible to compare and to discern. In the past 60 years, ethnoarchaeological reports from Africa and Asia have found their way to many people interested and, combined with the archaeological data sets, literally thousands of experiments with shaft furnaces and other prehistoric and early historic types were executed across the world. Especially in the United States, groups of archaeologists/craftspeople are very active in iron smelting. One of the advantages of iron smelting is that it was executed in many regions across the world which makes it easier for people to become familiar with it in their local environment. More clearly, these experiments and the vast amount of reports of them have made it possible for archaeologists to discern the different steps, methods, and their by-products. 

In 1967, a construction built in Lejre (Denmark) resembling an Iron Age house was deliberately set on fire and excavated later. Such experiments take time, courage, and a stable physical environment. 

The scene for the fire was planned in detail, with inventory and stock put in place where needed. Small porcelain cones were mounted across the house as part of the registration of temperature. Surprisingly for the experimenters, the house burnt down in as little as 30 min. A few days after the fire, small test pits were excavated. In this excavation, different layers of ash were discernible as well as different sources of clay and loam (walls, floor, etc.). 

These different features were much more difficult to recognize in the 1992 excavations. The people excavating in the second phase were unaware of the documentation of the fire in 1967, just like archaeologists nowadays excavate houses without knowledge of what exactly they will find until they do make finds. To everybody's surprise, they made only very little finds, even if the house was only burnt down 25 years before. After the 1992 excavations, the undisturbed parts are left for the future.

The pity of this famous experiment is that there has been no money available to date to process the complete documentation of the constructing phase, the phase of use of the house, the burning down, and subsequently the excavation. Even if this could be done, the work comparing the data with original archaeological information on burnt-down houses has to be started first of all. 

In the 1980s and 1990s, different wooden ships were built in Denmark, Germany, and the Netherlands, resembling a medieval cog-like vessel. This kind of ship was used in the late Middle Ages in the North Sea and the Baltic Sea as trading vessel. As is often the case, money was acquired through European unemployment funds. The building of such new ships of old design has an important added value, namely promoting interest in the past, and therefore strengthening the position of archaeology. 

The different cog-like vessels built in the 1980s and 1990s served different levels of authenticity and different goals. Most important, the ships were meant to be used as seafaring vessels in modern ages. 

A major advantage of having these new ships built is that the original archaeological data receives renewed attention, not just from archaeologists, but from a range of other specialists as well, who all `see' things in the original data, which archaeologists did not identify before. Archaeologists do learn to see beyond what they know, but these insights might be limited. 

In some cases, archaeological details were copied into a ship, and people first found out about their use after sailing with the ship. This is the case, for example, for a triangular piece of wood, which decenniums after the excavations had to be planned in the correct location, which could be recognized in medieval depictions as well. It turned out to be a so-called beam-end fender.

The location of the beam-end fender in front of a through-beam on the outer side of the hull. Drawing by Morten Gᴓthche, Maritime Newsletter from Roskilde, Denmark, no. 7, December 1996, p. 15.
The beam-end fenders can be seen clearly on this town seal from Elbing c. 1350. From Maritime Newsletter from Roskilde, Denmark, no. 7, December 1996, p. 15.

Experiments in using such a ship are often restricted to short-term monitoring experiments (``does it work well?''). Longer-term monitoring, using log books and comparing these over the years, would be a cost-effective way of learning more. The different ship projects are in touch with each other and exchange experiences. If the results and experiences with such ships were to be combined, an interesting image would emerge.

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