3rd Experimental Archaeology Conference Abstract – Heather Hopkins
From the 3rd Experimental Archaeology Conference, 15th to 16th November 2008, Edinburgh University.
Experience versus Experiment: differing disciplines’ definitions leading to the answering of ‘unanswerable’ questions, a case-study using Roman dyeing
The scale of manufacture in Roman Pompeii has been subject to fierce debate. Moeller (1976) concluded that the dyeing industry had created a surplus for export. Jongman (1988) concluded that Pompeii relied on imports. These previous studies relied on theoretical assumptions. This study used a new approach: the problem was approached from experimental archaeology, and full-scale experimental replicas of the relevant parts of the dyeing industry were built and used to determine the parameters of the apparatus and to gauge its capacity.
The use of experimental replicas led to entirely new questions. This study had to satisfy both archaeological and engineering definitions of ‘experiment’, of ‘replica’, and of ‘how’ the apparatus operated. The founding experimental archaeology of the 1960s examined the artefacts at the macroscopic level to discover how they worked. The experiments of the 1960s were true experiments with unknown outcomes. Since then there has been a movement towards more predictable experiments. Engineers today examine materials at the microscopic level to predict behaviour and failure before the artefact is constructed. This study was able to use both of these approaches to understand the factors influencing the apparatus and to predict the outcome in a way that was impossible before.
A true experiment must replicate the design, the materials, the construction technique and the method of operation. A replica that differs from the original in any of these is an experience and not an experiment. An aesthetically and authentically reconstructed replica may not meet the criteria of a true experiment as the material properties, such as heat transfer and therefore fuel requirement, may differ. This study was able to use modern engineering to both substitute materials that were unavailable and predict the behaviour of other materials that could have been included. Construction and use of the experimental replica supplied data to allow an exploration of the materials at a micro level in engineering. The Finite Element Analysis allowed the determination of physical changes in materials during heating, the mode of failure of the apparatus and the timespan within which this occurred. Through this it was possible to determine the magnitude of output of the dyeing industry, that the maximum was far smaller than previously thought, to place the output within the context of the city and to understand the significance of the industry as a whole.
This study had to meet all of the definitions used in both experimental archaeology and modern engineering. The results from this study answered previously unanswerable questions through the application of a new approach and new techniques. This study provides a sequential case study by which the application of different techniques could be followed by those of differing backgrounds. As the study at each point satisfied both the archaeological and engineering definitions of experimental replication, the results are grounded in solid experimental science in differing disciplines and so may be used as a foundation for further experiment and understanding.