Cultural Heritage Imaging


Revealing Inscriptions, Reading Surface Texture, and Documenting Change with RTI at Sardis by chicaseyc
January 24, 2016, 3:47 pm
Filed under: Guest Blogger, On Location, Technology | Tags: , , , , , ,

Our guest blogger, Emily B. Frank, is a student conservator on the Sardis Archaeological Expedition. Currently she is pursuing a Joint MS in Conservation of Historic and Artistic Works and MA in History of Art at New York University, Institute of Fine Arts. Thank you, Emily!

Sardis, the capital city of the Lydian empire in the seventh and sixth centuries BC, is often best remembered for the invention of coinage. Remains of a monumental temple of Artemis, begun during the Hellenistic period and never finished, still stand tall today. In Roman times, the city was famous as one of the Seven Churches of Asia in the Book of Revelation. In the fourth and fifth centuries AD, Sardis boasted what is still the largest known synagogue in antiquity. Sardis flourished and continued to grow in the Late Roman period until its decline by the seventh century AD.

Archaeological excavations at Sardis began over a century ago and are currently led by Dr. Nicholas D. Cahill, professor of Art History at the University of Wisconsin, Madison. The excavated material is vastly diverse and the conservation efforts there equally so. Conservation this season, under Harral DeBauche, a third-year conservation student at New York University, Institute of Fine Arts, supported active excavation across over 1,000 years of antiquity and addressed a number of site preservation issues. RTI greatly benefited the conservators and archaeologists in a couple of significant ways.

Significant finds with extremely shallow incised designs/inscriptions and impressions were made legible with RTI. RTI was helpful in understanding a bronze triangle recovered from the corridor of a Late Roman house (Fig. 1).

TriangleSetupImage-Fig1

Figure 1: H-RTI setup used for small objects at Sardis.

The triangle is incised with three images of a female deity and a border of magical signs (Fig. 2). Its use is likely connected with religious ritual practice in Asia Minor between the third and sixth centuries AD.

Figure 2: RTI of the bronze triangle in cumulative unsharp masking viewing mode.

Figure 2: RTI of the bronze triangle in cumulative unsharp masking viewing mode.

The legibility of the inscriptions, aided by RTI, reinforced the connection between the triangle’s inscriptions and material and written sources. Two comparenda for the triangle, one from Pergamon and one from Apamea, were identified, and the magic symbols on the triangle were connected with rituals described in a the Greek Magical Papyri.  RTI also aided in decoding and documenting a lead curse tablet and in understanding the weave structure of bitumen basketry impressions.

Additionally, a multi-year biofilm removal project of the Artemis Temple at Sardis is currently underway, headed by Michael Morris and Hiroko Kariya, conservators in private practice. The removal of this biofilm is carried out by a six-day process. RTI was used experimentally to document the changes to the stone throughout the removal process (Fig. 3).

Figure 3: H-RTI setup used for documentation of the biocide removal project.

Figure 3: H-RTI setup used for documentation of the biocide removal project.

RTIs were taken before treatment, during treatment (day 3), and after treatment (day 7). Because the biocide continues to work for months after its application, a final RTI will be taken next summer. Initial comparison of the images showed no loss to the stone surface as a result of the biofilm removal process. All very exciting!

To find out more about the excavations at Sardis, see http://sardisexpedition.org/.