One of the most exciting parts of field work is getting to discover objects that haven’t been used or seen for thousands of years, but the second best part is getting to preserve them so that they can be used for research or appreciated as part of human history. Artifacts often require some degree of stabilization once they are excavated. The process of excavation introduces oxygen which can also accelerate decay and corrosion. Because of this, it is important that each object is examined and its condition noted to ensure we can prioritize which artifacts require treatment first.
One of the most exciting finds this summer were several bells that were excavated from a burial context. These were brought back to the East Carolina Conservation Laboratory for further examination and preservation.
Two bells from a tomb context. The left bell is conserved and the right is untreated.
Photo by S. Grieve.
Conservators complete a thorough examination which documents areas that may be damaged or look for signs of use. We then go through a process of mechanical cleaning to remove surface dirt which could also be masking features. We often look for evidence of maker’s marks, surface decorations or residues; therefore, extreme care must be used to only remove material that will cause deterioration in the future! This is often done under a microscope to ensure we have a thorough understanding of the metal surface.
Conservators using a microscope to assist in cleaning the bells.
Photo by East Carolina Conservation Lab.
Since the bells were made of such thin copper alloy metal, we had to be careful during handling and cleaning. Early metal processing of copper alloys, in particular bronze, often demonstrate characteristics such as cracking and fragmenting. While we have confirmed that the bells are copper based, we suspect that they may be alloyed with tin to produce a bronze-like metal which was strong and easily cast. Further analysis with X-Ray Fluorescence may reveal the exact composition and assist archaeologists in determining the origin of the metal production.
During the mechanical cleaning process, we discovered a strange substance in the bowl of the bell. The substance resembles an inorganic material to the naked eye, but upon manipulation, it behaves like an organic material. We also didn’t find any evidence of a clapper that would have been present in the bell (based on our type of bell). These two factors indicate that perhaps these aren’t bells at all! If they are not bells, what are they?
Further testing with organic residue analysis techniques may reveal more details about use. Samples will be used from pieces that were already detached to determine what the substance may be. While our analysis and study is ongoing, one thing is for certain: these artifacts continue to tell stories long after they are removed from the ground and we’re here to listen!
Written by Susanne Grieve, Director of Conservation, East Carolina University