The talk at the Essex Egyptology Group meeting this September was given by one of our members - Stuart Baldwin. He's interested in the development of the Egyptian pyramids over time, and in how the Egyptians managed to build such monumental structures with such early technology. His talk presented what he's learnt about the subject, as well as several entertaining asides (which I generally shan't try and reproduce in this writeup, translating someone else's jokes from speech to text is an exercise doomed to failure!).
Baldwin started by giving us a bit of an overview of Egypt from a geological perspective - the country sits on the north-eastern corner of the African plate, near the boundaries with the Indo-Australian plate and the Eurasian plate. The northern part of Egypt around Cairo is blessed with many of the rocks and other things that the Egyptians used. To the west of the Nile near Giza are deposits of limestone, natron and gypsum. Out to the east, near the Red Sea coast, are deposits of copper. Of course granite is not nearby, and needed to be quarried and transported from the south of the country near Aswan. As well as this the Nile river brings fertility to the region, before the Aswan dams were built each flood brought 400 million tons of water through Egypt which spread across the land depositing mud and creating fertile soil.
The Egyptians are famous for being dead, and for taking their stuff with them when they died. One of their key beliefs is that the Ka, the life force or personality of the person, needed the person's body to survive and needed to be fed with offerings of food and drink. In the pre-dynastic era people were at first buried in the sand where they were naturally mummified. But bodies buried like this were easily disturbed by animals and so tombs got deeper, and eventually were even built into the bedrock under the sand. Pharaohs and nobles had structures built above their tombs which we call mastabas as they look like a sort of bench called a mastaba. These were built in cemeteries at both Abydos and Saqqara, and often a Pharaoh had a tomb in each place (one of which was symbolic). Mastabas are generally built out of mudbricks - which are quite large, Baldwin showed us a mockup of a brick which was much larger than a modern house brick, perhaps about the size of a breeze block.
True pyramids evolved from mastaba tombs. Baldwin explained that the pyramid shape was symbolic to the ancient Egyptians. The primeval mound that rose from the waters in one of the Egyptians' creation myths was shaped like a pyramid, and was called the benben. This name was also later given to the pyramid shape at the top of obelisks, and to the capstone (pyramidion) of pyramids. The benben stones were also thought to be shaped like the rays of the sun. It's important to remember that the tombs of these Pharaohs weren't just places to put their bodies, they were also statements of power and full of symbolism.
The Pharaoh Djoser took the first step in the evolution of the pyramid around 2630 BCE. His tomb is the Step Pyramid at Saqqara, which is effectively 6 mastabas placed one on top of the other. This was the first massive stone monument in the world. As well as a burial chamber in the rock underneath there are also 3 miles of tunnels and 400 rooms. The stone blocks used were much bigger than mud bricks, Baldwin had brought in a mockup of one to show us the size and it looked to be about as big as a small person. The pyramid didn't stand alone in the desert, as with all later pyramids it was part of a large complex including several temples - the outer perimeter was 1 mile in length. Baldwin next took a slight detour to tell us about the architect of this pyramid complex: Imhotep. Later in Ancient Egyptian history Imhotep would be deified. His skills were many and varied, he wasn't just an architect he was also regarded as the founder of medicine, Baldwin referred to him as the Leonardo da Vinci of the Ancient Egyptian world. It wasn't just posthumously that he was respected - during his lifetime he held many titles, including the splendid sounding "Supervisor of Everything in the Entire Land".
Sneferu was the greatest pyramid builder - he built three different pyramids during his lifetime. The first of these was at Meidum, and it collapsed. The next one is the Bent Pyramid at Dashur, which changes angle part way up. The third and final one was the first true pyramid, the Red Pyramid (also at Dashur). The one at Meidum was actually started by Sneferu's father, and the original design was a step pyramid with an above ground burial chamber and a corbelled roof. The change of angle in the Bent Pyramid has attracted many theories over the years - had the pyramid at Meidum already collapsed so they were worried about the Bent Pyramid? was the king ill so they finished it off briskly (then he recovered)? or was it planned all along? Baldwin explained that there's evidence that the last of these is actually the case. Partly for architectural reasons (it redistributed the forces to make the pyramid more stable) and partly for symbolic reasons - the shape is that of a benben stone sitting on top of the primeval mound. The Red Pyramid was built at the same angle as the upper part of the Bent Pyramid and its burial chambers and antechambers are all above ground. If you compare the three pyramids the building techniques change over time. The blocks get larger and more regular. They are also placed in a different orientation, the later one is stronger. And the burial chambers rise within the pyramid as well.
After Sneferu came his son Khufu, who built the Great Pyramid at Giza. This is the largest monument of its kind every built, it's also the most measured & surveyed building on the planet. The entrance we use today was made in the 9th Century CE. The inner core of the pyramid is made of rough cut blocks, and the outer core uses bigger more regular stones. And the outermost layer is a casing of Tura limestone which is very white, and Baldwin also pointed out that you find a lot of Foraminifera fossils in this limestone (and thus all over the Giza plateau). The Great Pyramid has several chambers - the first built was an underground chamber that was never used. Nothing was found in any of the chambers except the large granite sarcophagus. Baldwin estimate that with the tools & techniques available it would've taken 2 men 5 years to make it. There are no antechambers (where the burial goods were stored) that have been discovered - a French architect, Houdin, has proposed that they are joined to the main burial chamber with a connecting tunnel sealed with a block that doesn't fit quite as well as all the others in the chamber. However there's no concrete evidence for them.
After our break for coffee & cake Baldwin discussed what's known (or not known) about how the Great Pyramid was built. One important point is that the workers were not slaves, in fact they were the general population and probably the best workers from the villages. They were divided into teams, which were then grouped together into larger units & so on up the organisation chart. From our perspective they didn't really have much in the way of tools, which makes it all the more incredible that they managed to construct such a large & precisely built monument. They had set squares and a knowledge of geometry that let them measure out the angles & straight surfaces correctly. They also knew how to find true north using the rising & setting of stars, which let them orient the pyramid. Much of the stone was quarried near the pyramids - this was the limestone that was used. The granite came from further afield, from quarries at Aswan, and was cut into blocks using only copper tools and the extra friction that you can generate using sand in conjunction with these tools. This is particularly impressive as copper is not very hard - Baldwin explained it is a 3.75 on the hardness scale where talc is at 1 and diamond is at 10.
The big granite blocks from Aswan were moved by boat during the flood season only. These (and the other blocks) were also moved on wooden sledges for the land portion of the journey, using oil & water on the sand to make them move more easily. Getting them to the site was the easy bit, relatively speaking, getting them up to the right place on the pyramid was a lot more difficult. There are many theories as to how that was done, but none have incontrovertible evidence to support them. Ramps must've been an important part of the solution, however. Baldwin spent some time describing one theory in particular, that of Brier and Houdin (the same Houdin mentioned earlier). They have proposed that the limestone casing of the pyramid came first, and the blocks were raised using a spiral pattern of internal ramps. They have some data in the form of microgravity studies of the Great Pyramid that showed appropriate anomalies, but nothing completely definitive. Even with ramps actually moving the blocks would be difficult. Wooden "rockers" have been discovered, and Baldwin speculates that they were not just used to rock the blocks back & forth up the ramps but instead bound on all four sides of the block to form a sort of wheel which would be easier to manoeuvre.
This was a very entertaining overview of the pyramids of Ancient Egypt - my writeup doesn't do the talk justice, because I've skipped over the many humorous moments that Baldwin inserted into his presentation.