Mapping the Distillery Site
Maps are an essential part of archaeology, recording data for analysis and documenting what the excavation destroys. Inferences about and interpretations of a site can be based on spatial relationships represented in maps. We can gain clues as to the date of a deposit, the function of a space, and even social and cultural hierarchies from maps. They are also crucial in educating the public and helping us visualize the past.
When I began working on the distillery project in May 2001, Mount Vernon's archaeology department was just entering the world of digital mapping. Donations of software, equipment and training from ESRI, AutoDesk, Trimble, and the National Park Service gave us tools to document our excavations at Mount Vernon within the broader cultural and natural landscape. We began the project by scanning and importing all the hand-drawn maps of the distillery site into AutoCAD 2000i. Each of the site's 45 ten-by-ten units had been drawn at different excavation levels. We used the most recent maps, the ones we believed were the most accurate reflections of the soil deposits and eighteenth-century features.
Once the maps were digitized, we had to decide what each line represented. For example: Which of the many soil layers represents the building's foundation trench? Are all of the linear soil stains part of the same feature? A small group undertook this subjective exercise, and I then assigned an AutoCAD layer to each stratum based on what we interpreted the soils to represent--all foundation cobbles on one layer, brick flooring on another, and so forth. The resulting AutoCAD drawing provided us with a digital archive of our hand-drawn records and the seed for integration with other maps.
Our digitized drawings were merged into one and imported into ArcView GIS 3.2. This software allows easier integration and manipulation of data. The resulting image can be represented at any scale, with any collection of features and layers, and can be integrated with other maps and surrounding architectural and landscape features. This has proved valuable for our understanding and interpretation of the site. For example, the patterns of archaeological features such as drains and heat-altered soil help us understand the flow or process through the distillery building. This physical evidence is analyzed in conjunction with historical research to better envision the eighteenth-century distilling industry.
Check out the site map, and post any questions you have to the bulletin board!