New discoveries

When “In the Artifact Lab: Conservation of Egyptian Mummies” was envisioned, we knew that there were a lot of unknowns – the idea was that this would be a working lab, so we would be carrying out much of the work that normally goes on behind-the-scenes to prepare objects for exhibition, in full public view. Many of the artifacts selected for examination and conservation in the lab had not been examined very closely for a long time. What we did know is that we needed to do a whole lot more research, documentation, and conservation on these pieces before they would be ready for display.

We're not just trying to look good-we're actually working!

We’re not just trying to look good-we’re actually working!

Anyone who has been following this blog knows that we have made several discoveries about some of these artifacts – the discovery of the fact that our mummy PUM I had a beaded shroud, for instance. Another artifact, or assemblage of artifacts actually, that we knew we’d be learning much more about is the outer coffin of Ahanakht.

One of the boards from Ahanakht's outer coffin, showing the side covered with columns of Hieratic inscriptions.

One of the boards from Ahanakht’s outer coffin, showing the side covered with columns of Hieratic inscriptions.

We currently have 15 pieces (all dissembled) from this coffin up in the Artifact Lab, and 2 more are on exhibit. We also have Ahanakht’s inner coffin, which is assembled and on exhibit here on the 3rd floor of the museum as well.

Ahanakht's inner coffin on exhibit in the museum

Ahanakht’s inner coffin on exhibit in the museum

Previously on this blog we posted some photos of some of the smaller “coffin boards” – or at least, that’s what we thought they were. There are 4 of these smaller boards and they were acquired with the other pieces of the outer and inner coffins. They are made of the same wood, have similar bands of hieroglyphs on one side, and have similar construction methods as the larger boards.

3 smaller pieces previously thought to be part of the outer coffin

3 smaller pieces previously thought to be part of the outer coffin

These boards haven’t required extensive conservation – so other than some examination and very minor treatment, most of the work on them so far has been curatorial.

Curator Dr. David Silverman has been working with Penn graduate student Leah Humphrey to transcribe and translate all of the inscribed text on the coffin boards. Dr. Silverman has determined from the text on 3 of the smaller boards that they are actually a part of a canopic box, not a coffin. These wooden containers usually were square in shape and held 4 jars, each of which had one of the 4 mummified parts of the deceased: the lungs, liver, stomach, and intestines. The 4th small board, however, remains problematic since its dimensions make it clear that it does not belong to either of the 2 coffins of Ahanakht. In addition, its size and the nature of the text inscribed on it, make it also clear that it is not part of the canopic box. Its text indicates that it is part of yet another coffin.

Examination of one of the canopic box pieces and the "mystery" board underway

Examination of one of the canopic box pieces and the “mystery” board underway

Research progresses in the hopes that we can figure out where/what the 4th mystery piece is from. This particular project is a good example of how “In the Artifact Lab” is an exciting and sometimes perplexing work-in-progress.

 

The Outer Coffin of Ahanakht – part 2

One of the boards from the inner coffin of Ahanakht, before treatment.

Previously I began to tell you about this multi-part artifact. Then, I was just starting to get acquainted with it. When conservators first look at any artifact, the first thing we think about is not where it’s from, not how old it is, not even what culture made it. The first and most important fact for conservators is what it’s made of. The material tells us what kind of problems it might have and what kind of treatments we can use or not use – it’s the starting point of everything we do.

The coffin boards are wood, with some paint applied. Four thousand year-old wood. Right away, that tells us something about what kind of wood it must be, since wood generally doesn’t survive so long in the archaeological record. Because there’s been a lot of research done on Egyptian materials, we can say with some confidence that the wood is cedar of Lebanon (Cedrus libani). Cedar is a prized wood because the trees produce chemicals that make them resistant to insect damage and various forms of rot.

A detail of the board showing construction details.


The first step of any treatment is careful examination. The coffin boards, despite being entombed thousands of years ago in the desert environment of Egypt and then brought to Philadelphia with its humid summers and desiccating winter heating seasons, appear to be in excellent condition for the most part; their most obvious problem being a thick coat of dust from uncovered storage for many decades. I documented the appearance of the board, noting its construction details, such as four wooden pegs and mitered edges. One curious feature was thin metal ribbons running in channels along the long axis of the board. I was unsure whether these were an original feature or something done in modern times to put the coffin back together. It seemed an unusually elaborate repair but the metal was in such good condition that I didn’t think it was 4000 years old. Even under a microscope, I couldn’t tell exactly what the metal was. There were slight traces of green corrosion, which usually means copper or copper alloy, but the metal was mostly dark grey and quite flexible, so it could be lead. I made a note to analyze it using our new portable X-ray fluorescence analyzer which has since happened and to do some research on Egyptian coffin technology. Dr. Joe Wegner, also an Associate Curator in the Egyptian Section, recommended a book about a similar coffin at the Boston Museum of Fine Arts (The Secrets of Tomb 10b) and there I found this information: “the sides have beveled edges fastened together by dowels and copper ribbons“. So it looks like those metal ribbons are original. Perhaps their unusually excellent condition has something to do with the cedar around them.

During treatment, showing dirt partially removed and tools used for cleaning.


Treatment was relatively straightforward. I used a HEPA-filtered vacuum with variable speed control to remove the loose dust from the surface of the board. Conservators choose their cleaning methods based on the type of dirt to be removed and the substrate from which it is to be removed. ‘Dry’ cleaning methods (those not using liquids such as water or other solvents) are generally less likely to damage the artifact and are preferred wherever possible, although care must still be taken to ensure that only the dirt is removed and not any of the original surface. By using a very small vacuum attachment at low speed and monitoring the process closely using a magnifying visor, I was able to clean the surface safely. Not very glamorous but I’ve discovered that this artifact has a pretty important role in the history of archaeological science – see my post on the Museum’s blog for information on that!

pXRF In the Artifact Lab

Our Conservation Department is fortunate to have a portable x-ray fluorescence analyzer (pXRF), and today we started putting it to use in the Artifact Lab!

Conservator Nina Owczarek uses the pXRF to analyze pigments on a wall painting fragment

What can we do with a pXRF, you might ask? Well, Nina Owczarek provides a good overview about the use of this instrument in a previous post and also in a presentation which you can watch by following this link.

I’ve used a pXRF before, but it’s been awhile, so today Nina came up and gave us all a refresher. Essentially, x-ray fluorescence is a non-destructive analytical method that uses x-rays to identify elements present in objects or samples. This technique is particularly useful for characterizing pigments and metal alloy components, and that is what we’re using it for in the Artifact Lab.

A view of Nina and I discussing the pXRF from outside the lab

After examining a few artifacts visually, we had some questions about materials and wanted to do some further investigation with the pXRF. For instance, we are interested in these metal ribbons on the Ahanakht coffin boards (see Lynn Grant’s previous post about the boards).

The pXRF positioned in contact with the metal ribbons on one of the smaller coffin boards

After examination of these ribbons under the microscope, it was still difficult to determine what type of metal they are made of. With the pXRF, after a 180-second scan and using special software, a spectrum was produced that showed a large peak for copper and very small peaks for tin, iron, arsenic and lead. We haven’t been able to analyze the data much yet, but this does tell us that these are indeed made of copper.

We will follow this post soon with more information and interpretation of our results.

 

The Outer Coffin of Ahanakht – part 1.

The outer coffin of Ahanakht, assembled, in an early photograph from the Museum Archives

One of the big projects the new Artifact Lab space is allowing us to work on is the Inner Outer Coffin of Ahanakht (E 16218A-P).  This artifact, currently in at least 15 pieces, has a long inscription in Hieratic script on the interior surfaces that Dr. David Silverman and his graduate student Leah Humphrey are working on transcribing and translating.

The scholars know that the coffin was made for an Egyptian named Ahanakht because his name is in the inscription.

Dr. Jennifer Wegner, Associate Curator in the Egyptian Section, showed me Ahanakht’s name as it would appear on the coffin inscription.

We know the coffin had been reassembled at one time but since was taken apart, probably to make it easier to store.  But that made it hard to access, since many of the boards are very large (the largest boards are 8.5 feet long), very heavy and awkward to move and space in storage is limited.  In the Artifact Lab, we had shelving custom built to accommodate the coffin boards so we could treat them and the Egyptologists could finally read their inscriptions.

The custom built steel shelving to house the large, heavy coffin boards in the Artifact Lab

Because the coffin is in many pieces which shouldn’t need a lot of conservation, it’s a perfect project for the staff conservators who will only be spending occasional stints in the Artifact Lab (unlike Molly Gleeson, the project conservator) so last Sunday I began work on one of the smallest of the coffin boards.  It’s been interesting.  I’ll fill in the details in my next post.

posted by Lynn Grant