Tuesday, April 8, 2014

Another National Geographic blog post

While I've been sick, another blog post made it on to the National Geographic site: http://newswatch.nationalgeographic.com/2014/04/04/continuing-excavations-at-an-ancient-burial-site-last-touched-in-1919/

Apologies for delay

I got sick at the end of the field season--a cold that turned into pneumonia. Slowly getting better, and I promise posts (and responses) when I'm back on my feet.

Wednesday, March 19, 2014

How tall was this pyramid (answers)

Due to overwhelming demand, I am giving my answer to the question of how tall our pyramid would have been when first built. The angle of the facing stones is about 73 degrees, and if you just do a calculation on that basis (yes, it’s trigonometry), you get a height of about 43 meters.

If you do a more detailed (and accurate) calculation based on the size of the blocks and the setback of each course, you find that the pyramid had about 72 courses of stone and that it was about 34.5 meters high.

These calculations are remarkable partly because the pyramid has a much lower angle now, and it’s only a bit over 9 meters high. So a very rough reconstruction shows what the profile of the pyramid would have looked like originally:

Is that even remotely plausible? Where did all that stone go??

We looked at some nearby sites, and it seems that it is plausible—there are some pyramids at the site of Nuri from about the same period of time that were built of solid stone and have survived better, and they could have been close to 34 meters high. They also have a profile like the one I’ve reconstructed here.

Pyramids at the site of Nuri

We don’t know where all the stone went…but some of it seems to have been used in the village over the past century or two. 

Conservation in action!

My friend and colleague from the Kelsey Museum at the University of Michigan, Suzanne Davis, has arrived to conserve and restore our finds, to consult on issues of architectural preservation (our local sandstone is mostly of really poor quality, very soft), and to help us think through our longer-term site management plan.

I haven’t talked much about objects we’ve found this year. It’s been an unusual season since so much of our effort has gone into excavating monumental structures that have mostly been cleaned out. The city wall soundings produced some whole ceramic vessels that had been left in medieval houses—you can see a couple of them being repaired on Suzanne’s table. They have bandages wrapped around them as if they had head wounds… We also have some Meroitic painted pottery from an upper level in the temple that should look nice when it’s put back together. And of course Suzanne does all this much better than we archaeologists would do on our own, so it’s great to have an expert here.

Tuesday, March 18, 2014

How tall was this pyramid?

Here's a real-life math problem: How tall was our pyramid when it was built? You can see that it has some original stones left toward the bottom, but the upper part is all rubble that would originally have been invisible behind a nice stone facing.

We are working on this question ourselves. Here is what you need to know...first, the base is 26.65 meters on each side. The pyramid has one course of stones with a vertical face (called the "plinth course"), then a series of stones with a steep angle--much steeper than the current slope of the pyramid. Here's a drawing that shows the slope of the stones.

Each course of stones is 48 cm high. The angle of the stones is such that if you draw it on graph paper, the top of the course is 11.5 cm back from where a vertical face would have been. (I never knew how hard it could be to write math problems...). This is shown by the triangle with dotted lines above.

In addition, the face of the pyramid was not smooth...each course was stepped back by about 7 cm on average. 

So, you should be able to calculate the original height of the pyramid using all that information. We're working on it too...but let's let the 6th graders (and younger) try this before posting any answers.

Saturday, March 15, 2014

More work of the Sudanese team at El Kurru

The Sudanese team working at El Kurru is directed by Prof. Abbas Sidahmed Mohamed-Ali, with Prof. Jamaal Karfis of the University of Dongola at Karima (pictured here) as field director. We have had a chance to become good friends during this field season. The Karima team is continuing to clean and restore the dramatic tombs of the kings and queens of Kush who also ruled Egypt as its 25th Dynasty.

In this photo, Prof. Jamaal is standing in the tomb of Queen Khensa. At El Kurru, a group of the major 25th Dynasty queens was buried in a cluster to the south of the royal cemetery (another group of probably less-major queens was buried in a cluster to the north).

Khensa was a daughter of king Kashta (whose name means “the Kushite”). Kashta was also father of king Piye (Piankhy), who was the first king of Kush to campaign far into Egypt. And Khensa was the wife of Piye, her brother (or half-brother), which was a common practice in the royal family of Kush.

I have my own connection to Queen Khensa. In an earlier excavation in the 4th Cataract region of Sudan, about 50 km upstream from El Kurru, we found a clay seal for an ancient jar that was impressed with the royal seal of Khensa. We found it on a gold-mining site that we were excavating, and it seems to suggest that the queen herself was involved in supervising extraction of gold from that region.

Friday, March 14, 2014

National Geographic film crew is here!

We’ll be part of a National Geographic film being made about the empire of Kush, and the film crew is here! The producer/director, James Barrat, has been interesting to talk to because he asks creative questions that we haven’t always considered before…and the NGS team has been great to work with. Here, I am getting ready to try using a robot with a camera to look into one of the inner rooms of the temple. I’m getting help from my Sudanese friend and colleague, Mansour Mohammed Ahmed, who is our foreman (he supervises all the local workmen).