Included here is a large industry which extended over the area between Lincoln and the Humber. The various production centres are united by a common kiln type and a basic range of vessel forms. At Swanpool itself, jars and bowls in grey ware were produced as well as a range of the more specialised products such as mortaria, colour-coated and painted vessels. Colour-coated bowls and beakers, and mortaria produced with a white-slipped surface are included here, the latter the most widely distributed product of the Swanpool industry.
Under the petrological microscope this can be seen to be a single fabric with different surface treatments. The three sectioned samples are united by a clean clay matrix, with common to abundant larger inclusions, frequently rounded and measuring c 0.3–0.4mm. Rare muscovite, and even less biotite, mica is present but not considered diagnostic. A wide range of other inclusions are regularly present, although less frequently than quartz, comprising clay pellets (normally quartz free), polycrystalline quartz, quartzite, micaceous fine-grained sandstone and siltstone, flint and feldspar. Opaques are rare to common and normally belong to the smallest size range. The slight variability seen between samples in terms of size and inclusions in thin section does not correspond with the different surface treatments, although in the hand specimen the coloured-coated fabric appears to be slightly finer.
Eleven kilns are known in the modern districts of Boultham, Bracesbridge and Swanpool (Darling 1977a, 33).
City of Lincoln Archaeology Unit
Lincoln City and County Museum
Darling, M J, 1977a Excursus on the Swanpool/Rookery Lane kiln complex at Lincoln, in A group of late Roman pottery from Lincoln, CBA for Lincoln Archaeol Trust Monogr Ser XVI–1, 32–7
Darling, M J, 1977b A group of late Roman pottery from Lincoln, CBA for Lincoln Archaeol Trust Monogr Ser XVI–1
Field, N, & Hurst, H, 1983 Roman Horncastle, Lincolnshire Hist Archaeol 18, 47–88
Hartley, K F, 1986a Mortarium stamps from the civil settlement, Doncaster, in The archaeology of Doncaster. 1. The Roman civil settlement (P C Buckland & J R Magilton), BAR 148, 143–49
Monaghan, J, with Hartley, K F, 1997 Mortaria, in Roman pottery from York (J Monaghan), The Archaeology of York. The Pottery 16/8, 930–43
Webster, G, & Booth, N, 1947 A Romano-British pottery kiln at Swanpool, near Lincoln, Antiq J 27, 61-79
Whitwell, J B, & Wood, K F, 1969 Three pottery kiln sites in Lincolnshire located by proton gradiometer (maxbleep) survey and confirmed by excavation, Prospezioni Archeologiche 4, 125-9
These samples are generally red-brown (10R 6/8) or orange-brown (2.5YR 5/8) with a grey (6/0) core, although examples are known which are completely grey in the break. The slip can be any shade of red-brown or brown through to almost black, and is commonly applied over a white underslip or wash which is normally only visible on the sherd break. On two of the examples in the collection the slip is a dark slightly yellow-brown (10YR 3/2), on the third a purple-red (10R 5/4). The sherds are usually hard with an irregular fracture and a smooth feel.
The fabric consists of well-sorted inclusions, primarily quartz (mostly 0.2–0.3mm occasionally to 0.8mm) set in a clean sparsely micaceous (silver) clay matrix. Sparse red iron-rich fragments are routinely present, falling between 0.2–1.0mm, and in the hand specimen appear to include clay pellets and rock fragments.
Our sample is orange-brown (2.5YR 6/8), sometimes with a grey or brown (7.5YR 6/4) core, while the surfaces are slipped cream (5Y 8/1). The fresh break reveals a hackly fracture in this hard fabric with rough feel. Reed-rim mortaria are particularly characteristic.
This sample is similar to the fabric described for SWN CC, but is slightly coarser in texture with the quartz normally measuring c 0.2–0.4mm, but ranging between 0.1–0.5mm. The surface is especially micaceous, with large silver flakes (up to 0.3mm) notable on the inside. A fragment of slag, possibly a stray trituration grit, is also visible in the break. Trituration grits are abundant, ill-sorted grains of black slag, measuring 1.0–5.0mm. Hartley (pers comm) notes that it is difficult or impossible to distinguish many Swanpool, Cantley and Catterick area 3rd and 4th century mortaria by fabric or other obvious means