Recycling misfired pottery - Forum Archaeologiae 9/12/98

Forum Archaeologiae - Zeitschrift für klassische Archäologie 9 / XII / 1998

RECYCLING MISFIRED POTTERY.
A standard practice of the potters at ancient Sagalassos ?

In the summer of 1987 a potters' quarter was discovered to the east of the town of Sagalassos (Pisidia, southwest Turkey), by the Belgian Sagalassos Archaeological Research Project [1]. The potters of Sagalassos were involved in the production of a wide variety of ceramic products using five different clay fabrics: tableware sets, oil lamps, figurines and oinophoroi (fabric 1), containers (fabric 2), tiles, bricks and water pipes (fabric 3), cooking pots and amphorae (fabric 4) and pithoi (fabric 5) [2].
The period of mass production started in early Augustan times, immediately after the region had been incorporated into the Roman empire, and continued without interruption into the first half of the seventh century AD. Recent evidence indicates that at least the production of tableware may have already started in the late Hellenistic period, from around the middle of the second century BC onwards. Considering the range of products that was locally manufactured and the distribution pattern of the Sagalassos tableware throughout the eastern Mediterranean, in particular, the mode of production of the potters of Sagalassos can be reconstructed as a manufactory. According to D.P.S. Peacock [3], this is the most developed mode of production in Roman times. Thus, the organisation of the production of the potters' quarter of Sagalassos can be compared to other centres of mass pottery production, manufacturing eastern sigillatas and later Roman red slip wares. At this level, producing pottery is life sustaining and requires the highest possible level of organisation and specialisation of the work process, resulting in a comparatively long training for the craftsmen. The best technological solutions have to be developed and standardisation for both the process and the products is inevitable. The products are obviously of the highest possible quality. In other words, the community of potters had to maximize their efforts for every single step of the production process of their wares. Recent evidence from the potters' quarter of Sagalassos suggests that the local craftsmen even managed to make the most of it after the worst of their nightmares had happened, being when their kiln load misfired. They apparently developed a routine of recycling misfired pottery for further use.
Excavations were undertaken in the potters’ quarter in 1989 at the so-called Site D [4] and in 1990 and 1991 at the so-called Site F [5]. A new series of sondages was started in 1997 and continued in 1998 in order to try to integrate the results of the archaeometrical research programme on the Sagalassos wares with the aim of reconstructing the production process of a Roman ceramic mass production centre in detail [6].

One of the main results of the excavations in the potters' quarter was the discovery of a series of concentrations of dumped pottery. Five major concentrations have been discovered so far, containing waste material of the first, second, third, fourth and fifth/sixth centuries AD respectively. Thus, nearly the entire production span of the Sagalassos wares is represented. No dumped material of the late Hellenistic period or of the seventh century AD has been found yet.
After processing the pottery of these dumps, the lack of complete or restorable vessels was striking. At first we related this fact to erosional activity, transporting the material over short distances of only a couple of metres on the slopes of the potters’ quarter. We postulated that during transport, the broken pottery was mixed to such a degree that vessels could no longer be reconstructed. The fact that sherds made from different clay fabrics were mixed with the majority of the material, the local tableware, was also considered to indicate erosional activity.
However, pottery waste was also discovered behind a mortared rubble wall, where it was protected from erosion, at the end of the 1998 season. Some lenses of ash and charcoal mixed with reddish, burnt earth were found between and over deposits of discarded pottery. In this concentration of waste material, which had remained more or less in situ where it had been dumped, still no complete or restorable vessels were found. This dump also consisted of a mixture of different local fabrics, again with dominant quantities of Sagalassos red slip ware. Closer inspection and more detailed quantification of the five concentrations of dumped material excavated so far revealed that the waste contained nearly no "truly" misfired pottery, that had been fired at too high a temperature, with sintered and bloating dark grey fabric as a result. These observations led to the conclusion that the dumps excavated so far, in fact, do not represent entire kiln loads dumped during a single operation, as we traditionally imagined them, but are rather concentrations of waste material which have grown over a certain period of time.

In other words, the potters of Sagalassos seem to have been sorting their waste. The truly misfired pieces were separated from the rest of the kiln load and dumped at still unknown places. Those vessels that were not completely misfired or simply did not meet the quality standards of the potters were also separated, collected and thrown on the heaps we have been excavating so far. The heaps grew gradually but steadily, and as a result contained a lot of pre-sorted, broken and unrestorable pottery.
In fact, we have to imagine that the potters who actually fired the kilns were highly specialised and singled out by the potters community to do this job [7]. Taking into account the price of firing and the economic value of the end product, the craftsmen would have done everything possible to prevent a kiln from misfiring. Because of their experience, when accidents did occur, they would have been aware of what exactly was the problem and how to keep the loss rate as low as possible. On the other hand, it was perhaps inevitable that some areas of the kiln which were too close to the fire nearly always produced waste. After opening the kiln, the potters seem to have sorted tradeable products from the rest, and went on to decide which vessels of the latter category could still be completely or partially recycled. Finally, the totally misfired pieces and the non-sellable vessels were dumped at different places. At this stage, it is not yet clear whether the different fabrics found together in the dump were actually fired together or were only mixed after dumping.

Of course, this entire procedure would not make sense if the potters of Sagalassos did not have a very good reason to reuse otherwise valueless pottery sherds. Archaeometrical analyses of the Sagalassos wares and the mortars used in the constructions at Sagalassos pointed out that pottery temper was an important ingredient of the local common wares and building ceramics in order to improve their structural stability [8] . Crushed ceramics were added to a type of local mortar as well. This particular mortar was used for constructions in direct contact with water, with the ceramic temper improving the hydraulic properties useful in retaining water and moisture [9]. It is very tempting to conclude that the potters of Sagalassos managed to maximize their efforts even after everything had gone wrong. It seems that they had set up a routine of sorting waste in order to recycle their "useless" ceramics by grinding it to small pieces and mixing it with clay or mortar. This procedure, operational from early Roman to early Byzantine times, may serve as another example of how ingeniously and efficiently they reused their "raw" materials.

[1] S. Mitchell - M. Waelkens, Cremna and Sagalassus 1987, Anatolian Studies 38, 1988, 53-64. Sagalassos I.
[2] J. Poblome, Sagalassos Red Slip Ware. Typology and Chronology (Studies in Eastern Mediterranean Archaeology 2)(1998); R. Degeest, The Common Wares of Roman Sagalassos from the First to the Seventh Century AD (Studies in Eastern Mediterranean Archaeology 3) (in press).
[3] D.P.S. Peacock, Pottery in the Roman World. An Ethnoarchaeological Approach (1982).
[4] M. Waelkens - S. Baser - M. Lodewijckx - W. Viaene - R. Degeest, Sagalassos 1989. The Rescue Excavation in the Potter’s Quarter and the "Sagalassos Ware", Acta Archaeologica Lovaniensia 28-29, 1990, 75-98.
[5] M. Waelkens - A. Harmankaya - W. Viaene, The Excavations at Sagalassos 1990, Anatolian Studies 41, 1991, 206-212; M. Waelkens - E. Owens - A. Hasendonckx - B. Arikan, The Excavations at Sagalassos 1991, Anatolian Studies 42, 1992, 91-97.
[6] J. Poblome - Marc Waelkens, Recent Excavations in the Potters’ Quarter of Roman Sagalassos, Near Eastern Archaeology 61, 1998, 129; J. Poblome - P. Degryse - I. Librecht - M. Waelkens, Sagalassos Red Slip Ware. The Organization of a Manufactory, Münstersche Beiträge zur antiken Handelsgeschichte (in press).
[7] R. Marichal, Les graffites de La Graufesenque (Supplément à Gallia 47)(1988).
[8] P. Degryse - R. Degeest - R. Ottenburgs - H. Kucha - W. Viaene - J. Poblome - M. Waelkens, Mineralogy and Geochemistry of Roman Common Wares produced at Sagalassos and Possible Clay Resources: Determination of Clay Raw Materials, in: M. Waelkens - L. Loots (ed.) Sagalassos V. Report on the Survey and Excavation Campaigns of 1996 and 1997 (Acta Archaeologica Lovaniensia Monographiae 10) (in press).
[9] W. Viaene - M. Waelkens - R. Ottenburgs - K. Callebaut, Archaeometric Study of Mortars used at Sagalassos, in: M. Waelkens - J. Poblome (ed.) Sagalassos IV. Report on the Survey and Excavation campaigns of 1994 and 1995 (Acta Archaeologica Lovaniensia Monographiae 9) (1997) 405-421.