After having spent most of the past year being buried up to my neck in Art Deco automobiles and motorcycles, I was more than delighted to get back in to the ancient groove in November and December, even though I worked evenings and weekends to make sure everything was done in time. This involved mostly lectures, talks and PowerPoint presentations, but it was all related to ancient things…
On November 19, I taught my Egyptology Seminar (it had been rescheduled from the spring because of the various deadlines for the exhibition). Also, due to this same lack of time, it was only a half day event instead of a full day affair, but it was very well attended nonetheless. The theme (well, title, really) was “Taking Care of Business at Pharaoh’s Court” and I presented with short lectures a number of important individuals who helped shape Egypt during its long history–Imhotep and Hemiunu (both from the Old Kingdom), Ahmose son of Ibana (New Kingdom) and Mentuemhet, the mayor of Thebes during the Third Intermediate Period and the Late Period. Luckily, Dr. Bonnie Sampsell—the author of the Geology of Egypt, who happens to be not only a geologist but also an amateur Egyptologist—kindly helped by giving one of the seminar talks. She presented Senenmut, Queen Hatshepsut’s trusted architect and royal nanny. That gave me some time to breathe…
On November 21 I spent the whole day at North Carolina State University as guest speaker, invited by Dr. Dru MgGill, archaeologist at the Department of Sociology and Anthropology. I presented the scientific methods used in museums to study ancient ceramics for the students taking Special Topics in Anthropology, Pots and People: Ceramics Analysis in late morning. Then, after a tasty lunch with my colleague, I spoke to two groups taking Unearthing the Past: Introduction to World Archaeology. I introduced them to the archaeology of ancient Sudan (Meroe and Dangeil) and mused the work of an archaeologist employed in a museum. Few students actually think of this option when considering jobs related to archaeology and material culture.
These were intense and very tiring months, but at least I was back into the ancient groove!!
After having identified the sculptures that still bore traces of pigments, the next step was to do x-ray fluorescence. This is a non-invasive technique used for the identification of non-organic pigments. It is not enough to note the presence of pigments on sculpture and take photographs of their location; we need to know of what these mineral pigments are made. This helps with the dating and authentication of the work of art because certain pigments are used in specific countries (or cultures) or during specific historical periods.
The analysis was conducted by Scott Pike, associate professor of geology and earth sciences at Willamette University, who had in his luggage his very handy x-ray gun. While we worked together, Scott explained how this Star Trek phaser looking thing works. This instrument send x-rays on the non-organic matter we wish to analyze. This results in electrons being bumped from their atomic orbital positions, releasing a burst of energy (fluorescence) that is characteristic of specific elements (elements of the periodic table, that is). The fluorescence is identified and recorded by the device. Each pigment will have its own combination of elements. Thanks to this technique, we can tell if the red pigment is actually red ochre (an iron oxide used in ancient Egypt) or cinnabar (mercury sulphide used by the Romans).
The x-ray gun is controlled with a computer. Although I did have my photo taken with very cool looking instrument (I just had to!), I assisted Scott by manning the computer while he held the portable XRF device to do the analysis. Elizabeth joined us in the galleries for a while and that allowed me to take a few pictures. Luckily, x-ray fluorescence does not require to be done in the dark. So we didn’t have to work late nights at the museum. All we had to do was stanchion off a work area around the sculpture under examination so that people did not disturb us… but we did have some people intrigued enough to stop by and observe what we were doing.
Acne treatment for our Celestial god? Not really. We have to take a reading from a neutral zone as well as the places where pigments are found.
The ram on the sarcophagus fragment is being poked in the eye by Elizabteth. The location of each analysis is identified on a picture. We just point with a stick.
Scott applies the x-ray gun to the eye of the ram, which has some traces of red pigment.
Scott and Elizabeth take readings on the sarcophagus fragment.
Computer monitor showing the spike chart during analysis.
The Cypriot Priest not getting laser eye surgery… the red pigment used to colour his eyes is being analyzed by the portable XRF device.
I’m exhausted. The last two weeks have been rather hectic, to say the least. There were several evenings when I didn’t get home until after 11pm… We’ve worked very hard on the classical marbles: we’ve examined the statues like we’ve never done before at the museum and used some weird equipment, too—it was great fun!
I’m too tired to go into details right now, so I thought I would share photos today and describe the various studies in later posts when I’m actually awake and coherent.
Is this thing set to stun? Yours truly with the XRF ‘gun.’
This is not a stolen Star Trek phaser, but a handheld XRF analyser. (It’s not set to stun.)
A flash, its battery pack and filters for ultraviolet fluorescence (on unit) and visible-induced fluorescence (blue filter on table) imaging. (Safety goggles are needed for UVF.)
The Iridium 192 housing unit used in gamma radiography. (The other device is a radiation metre.)
Yours truly holding a red LED spotlight during an infrared reflectography session.
Is this the sucker-mouth of a Mynock? Nope, it’s the LED ring light at the end of the microscope.