Ch-ch-changes (In the Artifact Lab)

Posted on December 21, 2013 by artifactlab

Update – this post contains blurred images of human remains. To read more about this decision, follow this link.

Visitors to the Artifact Lab these days will see a slightly different scene.

A variety of Native American objects currently in the Artifact Lab, including a war bonnet, baskets, a harpoon, a beaded vest and a wooden helmet.

Rockwell Project Conservator Molly Gleeson will be on leave for the next few months, spending time at home with her baby daughter. While she’s away, our intern Laura Galicier will continue to work on Egyptian artifacts such as the wooden heads or the demotic jar. But she’ll be joined by other members of the Penn Museum Conservation team, who will be working on a variety of projects. Because of various upcoming deadlines, a lot of what you’ll see worked on will be Native American artifacts from Penn Museum’s collections.

Penn Museum Conservation
intern Alexis North, working on moccasins for the Native
American Voices Exhibition.

In addition to Native American Voices, our new exhibition opening March 1, 2014, we will be loaning Native American objects to exhibitions at three other museums in the new year: the Quai Branly Museum in Paris, France; the Autry National Center of the American West in Los Angeles; and at Penn’s own Arthur Ross Gallery. At other times you may see a conservator working on material from ancient Cyprus or material from the Museum’s excavations at Ur. Whenever you come, there’s sure to be something interesting to see and our conservators will be happy to talk to you about whatever they’re doing or whatever you’re interested in at our open window times (weekdays, 11:15 – 11:45 am and 2:00 – 2:30 pm, and weekends, 12:30 – 1:00 pm and 3:30 – 4:00 pm). And you’re always welcome to submit questions or comments via this blog. We’ll continue to post regularly on the doings of the Artifact Lab and Molly may even find some time to write in from home.

A demotic jar

Posted on December 17, 2013 by lauragalicier

A pottery workshop (from LICHTHEIM Miriam, Ancient Egyptian literature, 1973)

Among the objects that an archaeological conservator treats, a very important one regarding the quantity is ceramic. Ceramic artifacts are widespread on time and many very different places; a lot of (if not all) civilizations on Earth made ceramics, so if you haven’t met one of those yet in a museum, it’s only a matter of time!

The one we have in the Artifact Lab is an Egyptian jar, from one of the past Penn Museum’s excavations on this site. Jars were used to contain fluids and are covered inside with a mixture of water and clay, to make it waterproof.

Here is a picture of the fragments before any intervention:

The jar before treatment.

This ceramic is covered with inscriptions painted in black ink (most likely a carbon ink) and the writing appears to be demotic. The Egyptian writing knew three different forms: hieroglyphic, which is the one you’re used to see on monuments; hieratic, which is a simplification of hieroglyphs, allowing the scribes to write faster for their administrative work on papyrus or pottery and rock fragments; and the demotic is a simplification of the hieratic, used from the VIIth century B.C. It is one of the writing that you can see on the Rosetta Stone.

Demotic writing on the Rosetta Stone.

Detail of the black inscription covering the jar.

This black ink is water soluble, meaning that water is highly prohibited to clean the inscribed areas !

Concerning its condition, the main problem of course is that the jar is broken into about 50 fragments. It was restored in the past so it still bears remains of an old adhesive on the edges and many fragments are still glued together. Moreover, the surface and the inscription are covered with dust and need to be cleaned.

Example of a particularly dirty fragment. The inscription is barely visible.

The next step will be to remove the old adhesive and to put the fragments together again. Eventually, we may have to fill some gaps in the ceramic, so as its handling could be easier and safer.

Those steps will be more detailed in several blogposts to come !

X-rays and the statues eyes

Posted on December 4, 2013 by lauragalicier

In a previous post, we told you that the two wooden heads were going to be X-rayed and CT-scanned, alongside with some other artifacts from the Lab.

In this post we will deal with what we learned about the wooden heads’ eyes from the X-radiographs only.

A lot of our readers will probably know what X-rays are, for they may have experienced them in a hospital. X-rays are also successfully used in Art and Archaeology (for a general overview and some examples, see SCHREINER et al, “X-rays in Art and Archaeology – An overview). The principle of the X-ray is to expose a material to x-ray energy of a particular wavelength. According to the molecular weight of the material, the x-rays will, or won’t, be allowed to go completely through it. The energy that does penetrate passes through to a detector.

In digital radiography, the data is then processed by a computer and, eventually, we obtain a picture where dense (high molecular weight) materials appear white and lighter ones (low molecular weight) are black.

X-ray photograph of E17911 – We can see a lot of termite tunnels and the big hole inside the head, on the right-hand side, and the shining eyes.

E17911, in profile – This picture allows us to see more clearly the structure of the eyes.

E17910 – Also helpful about the inserting of the eyes.

In these radiographs, we clearly see the structure of the inlaid eyes. In fact, those eyes are quite similar to those studied at the Louvre Museum on Kay’s statue (ZIEGLER, Les statues égyptiennes de l’Ancien Empire, Musée du Louvre, 1997, p.256). This statue is from the Vth Dynasty, not so far in time from our heads.

Eventually, we can conclude that the eyes are made of a metallic sheet soldered in the back, which is flat. It is shell-shaped and the hippo ivory is inserted inside. Then the black pupils (made of obsidian?) are placed in the ivory, maintained inside by an adhesive (resin ? plaster ?).

X-ray radiography photograph of Kay’s statue eyes (from ZIEGLER, 1997, p.256).

Structure of Kay’s eyes (from ZIEGLER, 1997, p.259); the back of the metallic part is flat and the edges were folded so as to form the eyelids.

Structure of Kay’s eyes and identification of the materials we have on Adu’s eyes (from ZIEGLER, 1997, p.259)

Fortunately, the Penn Museum has some inlaid eyes in storage, allowing us to figure out more clearly what we have on the heads.

The eye n.E6789B – Limestone and obsidian.

Back of the eye n.E12905A – Copper alloy.

Again, fortunately for us (yes, fortunately!), the Louvre Museum has a very interesting statue, also from the Old Kingdom, with missing eyes. This statue of a nobleman named Tcheti informs us on how the inlaid eyes were inserted into the wood.

Tcheti statue, Louvre Museum n.E11566 – Detail of the missing eyes.

We can see that a hole was cut in the wood, fitting the eyes’ size. We can suppose that an adhesive was used to prevent the eyes from falling off the statue.

As you can see, a conservation intervention, apart from treating the objects, can also allow us to study them more closely and to know them better.

We will talk about the CT-scan in a next post and, in the meantime, you’re more than welcome to visit us at the Lab or to post a comment below !