Sugar house artifacts document nineteenth-century refining techniques

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Sugar house artifacts document nineteenth-century refining techniques

October 27, 1994
By Pamela J. Cressey

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Drawing of a clay cone-shape mold inserted into a syrup jar during the claying process, which yielded two products--a dried white sugar "loaf" from the mold and molasses syrup in the jar. Photo Credit: Alexandria Archaeology.
Archaeology involves far more than digging through dirt to discover artifacts. While much of the archaeological process has a physical component, there is a great deal of conceptual thinking and analysis necessary to connect the pieces of the past to reveal the larger picture of historic life and thought.

The Moore-Mclean Sugar House investigation conducted by the City of Alexandria is a good case study of the archaeological process. After documenting the site with written and visual sources, the second step was excavation of the Sugar House site at North Alfred and Cameron streets. The excavation unearthed more than 10,000 artifacts and hundreds of structural elements, such as wells, a cistern, vats, drains, paths, foundations and basements.

Each artifact required washing, marking with its provenance in the soil, and cataloguing before entry into the Alexandria Archaeology Collection data base.

Next came the analysis stage of the process. We asked these questions: When were these different parts of the site and artifacts manufactured, used and discarded? What were their purposes and relationships to one another over time? What happened on this site? These questions require statistical analysis of the artifacts using their various dates of manufacture and comparison of the results with the soil stratigraphy.

Analysis also involves relating this information from the ground with the documentary data about who operated the site, tax values, insurance maps, slave censuses and a host of other site specific information. More research was also needed to determine where the sugar came from, the sugar refining technology of the 18th and 19th centuries, and production quantities.

The Sugar House was five stories high to accommodate thousands of sugar "loaves" while their liquid contents dried. Seven male slaves, two of which were youths, boiled, filtered and poured the sugar into cone-shaped clay molds. Through the use of pulleys, the heavy molds were brought up to the drying chambers on the upper floors. The 1820 Manufacturing Census recorded 5,000 each of cone molds and syrup jars at the Sugar House.

The first step in refining the raw sugar was the addition of lime water during boiling to aid in crystallization. The 2800 pieces of coral and shell from the West Indies found on the site were probably used as lime sources. After additional processing, the crystallized sugar was poured into the clay sugar cones inserted into the syrup jars. A topping of wet, white clay slip washed the remaining syrup through the sugar into the jar by dripping down a hole in the tip of the cone molds.

At last! Our mystery of the function of the cone-shape artifacts was solved. Next week I will discuss the final archaeology step, interpretation of the big historic picture from the broken fragments of the past.

Pamela Cressey is the Alexandria City Archaeologist.