Although it isn’t the most visually appealing artifact to come across in the lab, I still like finding coal, especially because of my background in geology. Artifacts like coal remind me that we’re not so different from the people who came hundreds of years before us. Though time has passed, we still need to keep warm and cook meals, especially this time of year.
Humans have been using coal for thousands of years as a fuel and heat source since it is easy to identify in nature, and can be mined from seams in sedimentary and metamorphic rock outcrops. When the English began settling in America and establishing colonies, there was an abundance of wood that could be used for fuel. But during the nineteenth century, America became more and more reliant on coal, not only as a heat source, but also to power the industrial mills springing up in the northeast, like in Lowell, Massachusetts.
Aside from excavated pieces of unused coal, we also find burned, or spent, coal. Some archeological excavations recover such large quantities of these materials that it can be a bit overwhelming. When it comes down to it, coal, at this time, can only really teach us about what types of fuels were being used at a site at a certain time, and where the coal may have been imported from, which can shed light on regional trade. However, these facts can often be easily discovered in the historical record. For the purpose of future research and the potential discovery of new ways to analyze artifacts, it is important to keep all artifacts collected from a site, including coal (check out our archaeology technology post!). However, one must also keep in mind the cost of caring for and curating hundreds of thousands of artifacts in perpetuity. How much money, space, and staff time should be spent storing boxes of coal, when it has such low research potential? How do we resolve the conflict of research and the reality of long term curation, keeping in mind that there is often limited space and funding?
When we are cataloging collections that have multiple bags of coal or other materials with low research potential (such as brick fragments and mortar), we sample down. This means that we keep a small representative sample from each provenience so that future archeologists have the artifacts, but not in an overwhelming amount that will hog valuable storage space. Lynne Sullivan and S. Terry Childs write that “Various kinds of sites, features, and materials must be represented in sufficient, yet practical, quantities to allow for meaningful comparisons” (Sullivan and Childs, 2003). Basically, there is no hard and fast rule for what materials should be sampled down, and this endeavor should be taken on a case by case basis, in the field, or in the laboratory.
As for the relationship of coal and naughty children, check out this news story to see one historian’s thoughts on the topic!
From all of us at NMSC, we wish you a wonderful holiday season, and a Happy New Year!
Sullivan, Lynne P. and S. Terry Childs. Curating Archaeological Collections: From the Field to the Repository. Archaeologist’s Toolkit Volume 6. Walnut Creek (CA), Lanham (MD), New York, and Oxford: Altamira Press, 2003.