Horváth László szerk.: Zalai Múzeum 17. (Közlemények Zala megye múzeumaiból, Zalaegerszeg, 2008)

KREITER ATTILA: A Celtic pottery kiln and ceramic technological study from Zalakomár-Alsó Csalit (S-W Hungary). Kelta edényégető kemence és kerámia technológiai megfigyelések Zalakomár-Alsó Csalit lelőhelyről

and irregularly fired on its interior and core. The vessel was built using the slab technique and the sherd is probably a slab itself, which is indicated by the firing marks on its cross section. The next slabs above and below of this slab were simply attached to this slab and no overlapping of slabs could be identified. The vessel was finished on a slow wheel or turn table. The fabric of the sherd shows increased amount of sand. The majority of quartz grains are opaque and white showing up to 1—1.5 mm in size. Maximum height: 5.7 cm, max. width: 12 cm, thickness range: ca. 1.2—1.5 cm. 22. Inv.No. 722.378.9.5 (Fig. 6/10): It is a light brown body sherd of an amphora. The sherd is oxidised on its exterior, interior and core. The vessel was built using the slab technique. The joining of two slabs is identified in the cross section. The slabs were simply attached together without overlapping. The size of one of the slabs was ca. 4.8 cm. The next slab broke irregularly and for this reason its size could not be measured. The vessel was finished on a slow wheel or tum table. The fabric of the sherd shows increased amount of sand. The majority of quartz grains are opaque and white showing up to 1 mm in size. Maximum height: ca. 8 cm, max. width: ca. 10.7 cm, thickness range: ca. 1—1.2 cm. Discussion of ceramic building techniques Celtic pottery building techniques are usually considered in terms of wheel made and handmade pottery but the technological aspects of Celtic pottery construction are not discussed in detail. In this paper particular attention is given to vessel building techniques since in different vessel types slab building was identified as the primary method of construction, which was combined with the slow wheel technique or tum table. On the sherds from the kiln wheel-marks are also present, suggesting that the vessels were worked on a wheel or turn table during some part of their construction. A closer look at the sherds, however, also shows characteristics of a slab building technique. The fragmented nature of the ceramics does not make it possible in all cases to ascertain whether the vessels were built of rings that are as large as the circumference of the vessel or they were built by a variation of slab building the so-called Morsel building. In the latter case flattened, rectangular clay slabs were joined together in a row to build the vessel wall around and then vertically (FEWKES 1940: 172). Morsel building method seems to be more probable for the vessels examined because in many cases it seems that the slabs were not joined together properly and during the firing process the vessels broke along almost straight horizontal and vertical lines where the slabs were joined together (e.g. Figs. 4/11, 4/12, 5/1, 5/2, 5/6, 5/7, 5/8, 5/9). This is particularly apparent in the case of vessels that have been reduced on their exterior and interior because when the vessels broke along the slabs during firing all the sides (cross section) of the slabs became reduced. During the analysis it was often observed that even though all sides of the slabs were reduced a fresh break of the sherds show that the cross section of the sherd was actually oxidised. The uniformly rectangular sherds give a strong impression that these fragments were the actual building units of vessels. The attachment of the slabs could also be observed. In some cases the top and bottom of the slabs were made flat onto which the next slab was simply attached or a shallow channel was made by a finger to accommodate the next slab, then the edges of the two slabs were slightly smoothed together. The signs of slab building are often recognisable on the sherds even if they did not break along their building units. For examples horizontal cracks are often present on vessel interior and/or cross-section (Figs. 5/3, 6/1 Ob). In other cases slabs overlapped each other, this practice made the vessels stronger since it allowed a better cohesion between the building units. It was observed that different sizes of slabs were used to construct different vessels or vessel parts. The height of the slabs varies between ca. 2 and 7 cm, although the majority of the slabs are ca. 5-6 cm high in particular in the case of amphorae. Regularities in building units for a particular vessel type (amphorae) implies a fairly good weight and volume management by the potters, although it is clear that more research is needed to assess possible correlations between building techniques/weight and volume management and vessel types. Nevertheless, ethnographic data shows that regularities in technological practices do indicate good weight and volume management (WALLAERT-PÊTRE 2001). Short slabs (ca. 2-3 cm) were applied where there is a sudden change in vessel curvature (Fig. 5/3). This practice is a practical way of overcoming breakage since shorter building units accommodate sudden changes in vessel curvature by decreasing stress in the clay. Sudden changes in vessel curvature are the regions where the most stress accumulates during drying and firing and it was an advantage to apply a shorter building unit rather than bend a larger slab. The base of the vessels was made of a flat disk to which the first vertical slab was attached. The slabs were simply placed on the disk vertically and the edges of the slab and the disk were slightly squeezed together. The slabs, in many cases, were not attached to the disk properly, which is indicated by the slabs breaking off the disk.