TECHNOLOGY

The technology of prehistoric has been well summarized recently by Ann Woods (Gibson and Woods 1990) and no reiteration of that work is necessary here save some short, introductory remarks.

In iron age Britain, as in the preceding Neolithic and Bronze Age, until the Roman occupation, only a limited number of techniques was used to build a pot: pinching, ring-building, coil-building, strap-building or slab-building. No wheel-thrown vessels are present in the British archaeological record until the introduction of Gallo-Belgic wares in the first century BC. This does not preclude the use of a wheel in the pre-Belgic Iron Age, however, and a wheel or a turntable could well have been used for the building or finishing of a vessel. Nevertheless, the technique of wheelthrowing does not appear in the British ceramic repertoire until the Roman conquest and is consequently outside the scope of this chapter.

Pinching, the first-mentioned of the other pot-building techniques, is the simplest method of manufacture. Involving pinching the clay outwards and upwards from a single ball to raise the sides of a simple pot. The technique is best suited to small cups or closed bowls but need not be confined to these forms; pinched bowls may well form a basis for larger vessels if supplemented by another technique. Woods has already clearly described the difficulties of recognizing this technique and the ease with which pinched vessels can be confused with similar but differently constructed vessels (Gibson and Woods 1990; 40-2).

Ring-, coil - or strap-building are closely related techniques and it is by these methods that the majority of iron age pottery vessels were made. In the first two techniques, cylinders of clay are rolled out and joined, one on top of the other, to build up the shape of the pot. In ring-building the pot is built up using distinct layers and in coil-building the cylinders overlap and spiral upwards. The technique of strap-building is similar save that the cylinders of clay are first flattened and joined together on edge so that greater height is given to the rings. The surfaces of the vessel are then smoothed over by the fingers or some other tool so that the rings or coils are hidden. Frequently many vessels are found to have broken along the line of a poorly bonded join (Figure 19.2) and the round surface of the clay ring or coil will be visible in the breaks. Join voids between poorly bonded cylinders may also be visible in the sections of large sherds. It is frequently impossible to differentiate between these closely related techniques in sherd material (Woods 1989).

Slab-building, as the term implies, involves the building of the walls of a pot from a number of slabs of clay: prefabricated pottery! Once more this is a difficult technique to recognize amongst sherd assemblies and its apparent rarity amongst the British material may be a direct result of the inability of scholars readily to identify its use, in stark contrast to the ease with which ring-building can be recognized.

Figure 19.2 Early bronze age food vessel showing join voids in the fabric and breakage lines along incompletely bonded coils or rings. (From Gibson and Woods 1990.)

The frequent softness, blotchy surfaces and dark core of many fabrics indicate that iron age pottery was open-fired in shallow pits or scoops or in surface bonfires. However, actual firing sites are difficult to detect with any certainty. Open-firings tend to be short with a rapid rise and fall in temperature (Woods 1989). Such flashfiring will leave little trace in the archaeological record even if the sites are used on several occasions (Gibson 1986b). Firing sites for Durotrigian Wares and the later Romano-British Black-Burnished Ware, which develops from the native tradition, have been located at Purbeck in Dorset (Farrar 1976). These firing areas were associated with firing wasters (vessels damaged in the firing process) and extensive areas of burnt soil: however, even here it was noted that the ‘natural surface did not present obvious signs of subjection to heat’ (Farrar 1976; 49). The absence of any evidence for kiln furniture and/or kiln superstructures further strengthens the argument that the vessels were open-fired in bonfires, as in the previous two millennia.

Finds of this nature are rare. Despite a growing body of evidence for regional ceramic manufacture (Peacock 1968,1989), production centres are elusive, presumably leaving few tangible archaeological traces. The discovery of the Durotrigian sites can most probably be seen to be a direct result of the industrial nature of the manufacture of Durotrigian and later Black-Burnished Wares exploited by the Roman invaders (Gillam 1957).

Despite the lack of archaeologically recognized manufacturing sites, open-firings, as mentioned above, can be attested by the ceramics themselves, which are often blotchy in their surface colouration, ranging from red to black. This uneven surface colour is a distinctive characteristic of open-firings and is a direct result of the constantly changing atmospheric conditions within a bonfire which are difficult to control (Woods 1989). Generally, an open-fired vessel will be basically yellow, red or brown in base colour as the iron oxides in the clay oxidize in the firing process. However, some portions of the pot may be subject to different firing conditions, depending on their contact with smoking flame, partially burnt wood or burial in ash. These portions will tend towards a grey or black colour, giving the vessel a blotchy appearance (see Gibson and Woods 1990: 44-56; Woods 1983, 1989).