The importance of pottery
Pottery is the ideal artefact type. Unlike many types of material culture that are perishable and leave little trace in the archaeological record, such as clothing, paper, and food, pottery is one artefact type that is virtually indestructible once it enters the archaeological record. Pottery that was made, discarded, and buried hundreds, even thousands of years ago, will emerge from the ground looking as if it were made yesterday.
Pottery has a number of other attributes that make it one of the most important artefact types that an archaeologist can find. Pottery is datable: different types of pottery, called ware types, were produced at different times. Because each ware-type has a beginning and ending manufacturing date, archaeologists can calculate a mean ceramic date (MCD) for each pottery type. A number of important statistical methods use Mean Ceramic Dates to provide robust chronologies for archaeological sites. One multivariate statistical method, correspondence analysis (CA), has been critical to our understanding of the temporal changes that occurred on the village sites on Nevis and St Kitts. You'll see references to MCDs and CA in the following sections that describe how the team's archaeologists have come to understand how slavery changed at each estate over time.
Range of pottery vessels
Pottery has a number of attributes, such as decoration and vessel form, that not only tell archaeologists the age of a specific piece of pottery but that also provide archaeologists with a sense of how much that pottery vessel cost. Pottery 'ware-types' each had their own price point, with Chinese porcelain, delft, and creamware being some of the most costly pottery ware types in the 18th century. Pearlware replaced creamware in popularity by the early 19th century. Pottery ware types could be plain or highly decorated. They were also made in difference vessel forms, each with their own specific use. Pots were used for cooking, trenchers and three-handled mugs for communal dining, teabowls, teapots, and other teawares were used in high-style social rituals such as tea drinking. Chamber pots replaced the need for a trip to the outdoor privy in the middle of the night. Decoration, or the lack of it, vessel form, and ware type all combined to create a vessel that would enter the market at a specific price point. Both free and enslaved consumers on Nevis and St Kitts had access to a wide variety of imported pottery offered in a range of prices.
Over half of each village's pottery assemblage was comprised of low-fired, locally-made coarse earthenwares known as Afro-Caribbean (AC) wares. Afro-Caribbean vessels were most often made in utilitarian hollow forms such as jars, pots, and bowls. Charred residue on the interior of sherds indicates that many of these vessels contained food and were used as cooking pots that were placed directly over a fire. Jars were used for food storage and transportation and bowls for food consumption.
Documentary evidence indicates that enslaved women were the primary producers of Afro-Caribbean pottery on Nevis and St Kitts. Finding them on village sites not only speaks to women's labour but also their ability to produce goods that may have been sold or traded in local markets for cash or goods not provided by owners.
One major goal of the St Kitts-Nevis Digital Archaeology Initiative is to further our understanding of the dramatic changes seen in the frequency of Afro-Caribbean pottery on slave sites. For example, the presence of AC wares peaked on all three villages in the 1780s and then declined. Were these locally-made wares produced by specialists or by all households? Did the clays come from each village or from a few, widely shared sources? To answer these questions, archaeologists from the University of Southampton (UK) and the University of Tennessee conducted petrography and instrumental neutron activation analysis (INAA) on a sample of Afro-Caribbean sherds from each village.
Video: Elaine Morris
Elaine Morris on Nevis, discussing her research into Afro-Caribbean pottery.
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Video: Barbara Heath
Barbara Heath discussing her research into Afro-Caribbean ware.
Read a transcript of this video
The results from INAA indicate that Afro-Caribbean sherds found at Jessups and New River, the Nevis village sites, were made on Nevis, while sherds found at The Spring and other St Kitts sites were produced on St Kitts. These results are intriguing and the small sample suggests that vessels were produced locally and not traded between these two islands. None of the sampled sherds were produced on other Caribbean islands. This is somewhat surprising given the robust trade in Afro-Caribbean pottery that occurred throughout the Caribbean in the 18th and 19th centuries.
Petrographic analysis of 14 sherds from the New River villages and 14 sherds from the Jessups villages corroborated the INAA results (Morris 2009). The strong similarity among the Nevis samples is in contrast to strong variability among petrographic samples from sites on St Eustatius, where eight distinctively different fabrics were identified (Bell 1988). This difference in variability (low for Nevis but high for St Eustatius) could be due to the St Eustatius site's location in the capital and port, Oranjestad. The capital may have been a magnet for different potters from around the island who could sell their wares to a wider market. The capital was also the largest port in the region and may have served as transshipment point of Afro-Caribbean wares made off-island. As the two sampled populations of Afro-Caribbean pottery on Nevis came from slave villages, not Nevis's capital Charlestown, we may simply be observing local production for local consumption.
Mean Ceramic Date
A mean ceramic date is an estimate of the centre of gravity of the period over which a pottery assemblage accumulated. MCDs are computed as the weighted average of the manufacturing span midpoints for a suite of pottery types present in an assemblage. The weights are the frequencies of the respective pottery types. This gives greater weight to the manufacturing midpoints of the more frequent types.
Correspondence analysis is a multivariate statistical method that estimates the position of a set of artefact assemblages along an underlying gradient or dimension on the basis of the relative frequencies of pottery types in each assemblage. The idea here is that the underlying gradient estimated by CA is correlated with time. The spacing of the assemblages relative to one another on the gradient is a function of how similar their relative frequencies of pottery types are. Similar assemblages are close to one another. Very different assemblages are far apart. Assemblages that are located near each other along the gradient estimated by CA are assigned to the same temporal phase. DAACS uses correspondence analysis to seriate assemblages and build intrasite chronologies.
Instrumental Neutron Activation Analysis (INAA)
Instrumental Neutron Activation Analysis (INAA) is a sensitive analytical technique used to identify major, minor, and trace elements in pottery and stone samples from archaeological sites. For this project, INAA was used to identify the chemical composition of 94 sherds and 7 clay samples from Nevis, and 46 sherds and 5 clay samples from St Kitts. The chemical composition of the pottery sherds was compared with the chemical composition of the clay samples. These data allowed researchers to identify the source materials for the pottery, and indicated that pottery found on St Kitts was produced from St Kitts clay sources and pottery found on Nevis sites was produced on Nevis using Nevisian clays.
Petrography is used by archaeologists to identify the mineral components of the clay fabric, or paste, that is used to make pottery. The mineral components of pottery pastes can identify the geological sources for both the clay and the rock fragments, also known as non-plastic paste inclusions, used in constructing pottery pastes. Petrography provides important information about where and how potters acquired the clays and non-plastic paste inclusions used in the pottery fabric. It can also help determine the presence of non-local clays and paste inclusions. Non-local clays would suggest that pottery was being produced off-site and traded into the area.