lewis, a. et al. ct scanning cocodrile mummies. 2010

8/3/2019 Lewis, A. Et Al. CT Scanning Cocodrile Mummies. 2010

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Inside The Conservator's Art

A behind-the-scenes look at conserving Egyptian artifacts at the Phoebe A. Hearst Museum ofAnthropology

http://conservationblog.hearstmuseum.dreamhosters.com/?p=460

{ 2010 04 28 }

In the belly of the beast: CT scanning twocrocodile m um mies

In February 2010 we had the opportunity to CT scan two crocodile mummies currently on display as part ofThe Conservators Art: Preserving Egypts Pastexhibition. Dr. Rebecca Fahrig of Stanford UniversitysDepartment of Radiology generously facilitated the CT scanning of PAHMA 5-513, the unwrappedcrocodile mummy with babies, and PAHMA 6-20100, the wrapped crocodile mummy.

Dr. Rebecca Fahrig oversees the placement of PAHMA 5-513 on the high resolution CT scanner in herlab.

Mummy studies and CT

Computed tomography (CT), a radiographic imaging technique used extensively in the medical world, hasbecome a powerful tool for the study of mummies. CT scanning creates a three-dimensionalrepresentation of the subject by digitally combining slices, or x-ray images acquired at different angles.CT is a non-destructive, non-invasive method for investigating mummies, allowing researchers to answerbasic questions about the nature of wrapped mummies and to gain insight into mummification proceduresand pathologies that may have afflicted the deceased. CT provides much more detailed information than

traditional x-rays because of its three-dimensionality, allowing us to view internal features from a variety ofangles and to recreate very accurate renderings of the subject.


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Research questions

We aimed to answer a number of questions about the mummies with the CT scans. These included:

Is there really a single adult crocodile inside of the suspiciously flat wrapped mummy with the paintedmask? If not, whats in there?

What new information can we learn about the elements used to create the wrapped crocodile mummy?Can we better characterize the plants, textiles and pigments used?

Can we see whether the crocodiles died of natural causes or were killed by humans? Can this informationhelp to reveal whether they were sacred animals worshiped as embodiments of Sobek, the Egyptiancrocodile deity, or were killed expressly to create votive mummies for pilgrims to dedicate?

Can we determine how the crocodile mummy with babies was mummified?

Can we tell what gender the crocodile mummy with babies is?

What else can we learn about how these crocodiles lived and died?

Packing and transportation

Because both mummies had undergone conservation treatment, they were stable enough to travel fromUC Berkeley to Palo Alto, CA to undergo CT scans. However, the mummies are inherently fragile andrequired careful packing in order to safely transport them. We created customized boards and cratesdesigned to immobilize the mummies and to protect them during transit in the museum van.

Intern Ramsay Macfie helps to attach 5-513 to a foam-lined wooden carrying board.

Both mummies had already been outfitted with long-term mounts/supports upon which they always rest.The supports consist of rigid Plexiglas padded with Ethafoam (closed cell polyethylene foam) andpolyester felt. Ethafoam tri-rod was used to create a bumper that follows the contours of each mummy,holding it snugly in place on the support.


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Allison builds a support for PAHMA 5-513, attaching Ethafoam padding to a piece of Plexiglas cut to theshape of the crocodiles underside.

The supports are covered with muslin or Tyvek (smooth archival non-woven fabric). Velcro straps sewn tothe bottom of the supports can be used to attach the supports to larger boards for display or travel.

To transport the two mummies, we placed them and their supports on long wooden boards covered withplanks of Ethafoam and created Tyvek-lined Ethafoam braces to further immobilize them.

PAHMA 6-20100 and PAHMA 5-513 on their carrying boards before travel to Stanford. 5-513 has itsTyvek-lined braces in place.


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Wooden skewers (a conservators best friend) held the foam braces firmly in place. The boards wereplaced in crates lined with two types of foam designed to reduce shock and vibration.

PAHMA conservator Jane Williams and Ramsay crate 5-513.


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PAHMA Designer Marco Centin and Jane begin to uncrate 6-20100 at Stanford Hospital.

Scanning the mummies

In order to maximize the amount of information obtained on the trip, each mummy was scanned twice. Firstthe mummies underwent clinical CT scans at an outpatient facility. These scans allowed us to quickly get ageneral sense of the interior of each mummy.

6-20100 in the clinical scanner.


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At the clinical facility we also performed dual-energy scans, which utilize x-rays of different energies todiscriminate between objects of comparable density that image similarly. After the clinical scans, webrought the mummies to Dr. Fahrigs lab on the Stanford campus where we scanned them with her highresolution CT scanner.

Preparing to scan 6-20100.

Scanning 5-513 at Dr. Fahrigs lab.


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So what did the CT scans reveal? Stay tuned for the results!

Posted by Allison on Wednesday, April 28, 2010, at 8:45 pm. Filed under Conservation treatments,Mummies and mummification, Scientific analysis. Tagged Crocodile mummy, CT scanning, RebeccaFahrig. Follow any responses to this post with its comments RSS feed. You can post a comment or

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lewis, a. et al. ct scanning cocodrile mummies. 2010

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