- Introduction
Built as tombs for the Egyptian Pharaohs and their Queens, the three largest examples of pyramids in Egypt are situated at Giza on the west bank of the River Nile. Of those three, the largest of all, known as the “Great Pyramid” was built for the pharaoh Khufu and is the only one of the Seven Wonders of the Ancient World that is still in existence. According to “The Egyptian Pyramid” – an article on the Smithsonian website – that pyramid's base covered an area in excess of 13 acres and the triangular side faces were at an angle of almost 52degrees to the horizontal with a maximum length of some 755 feet. At the time of building it stood around 480 feet high; though today its height is about 30 feet less. For almost 4,000 years it was the tallest structure ever built. The stone blocks used in its construction average over two tons in weight, though the largest limestone blocks may be as heavy as fifteen tons, with some granite beams much heavier at around 70 tons or so. In total, it is estimated that the Great Pyramid (sometimes called the Pyramid of Cheops) weighs approximately 7 million tons and comprises over two million individual blocks.
This largest pyramid was constructed over a 23-year period, from 2589 to 2566 BC. However, pyramid building in Egypt – according to the Smithsonian article – began in around 2780 BC and continued over a period of about 1,000 years, albeit the pyramids constructed tended to be on a smaller scale as time went on.
The typical shape of the Egyptian pyramid is a structure having four smooth-sided triangular sides, rising to a point, all built on a square base. In a Penn State University article (2008, March 28): How Were The Egyptian Pyramids Built?, Donald Redford, professor of Classics and ancient Mediterranean studies at Penn State, believes that the shape symbolizes the sun’s rays. He says that view is based on the legend that “The Egyptian sun god Ra, considered the father of all pharaohs, was said to have created himself from a pyramid-shaped mound of earth before creating all other gods”.
Although the building of the pyramids, especially the Great Pyramid, was complicated, Redford believes that it was not such a mammoth task as some believe. He notes that it took just 23 years to complete, in comparison with the Paris Notre Dame Cathedral which took just under 200 years.
The custom of the time was to start construction of a pharaoh’s pyramid as soon as he ascended to the throne. The new pharaoh would appoint and collaborate with an architect, a construction overseer and a chief engineer, and choose the location for his pyramid. This would usually be on the Nile’s west bank, as the departed pharaoh’s soul was supposed to join with the sun as it descended towards the horizon, then continue with the sun for eternity. The site’s proximity to Memphis, the old capital city – about 12 miles from the modern city of Cairo – was the other factor influencing the choice of location for the pyramids.
- Pyramid Construction
First, some intriguing statistics given on the Omni Report website under the heading: The Great Pyramid Controversy Part 2: The Big Deal:
- The centers of the three pyramids of Giza together form a triangle of Pythagorean proportions, sides 3:4:5;
- The Great Pyramid is aligned exactly (to within 3 minutes of arc) to the Cardinal Points.
These details suggest a tremendous precision in the construction, which is also said by some to be borne out by the accuracy of the individual blocks and the perfection of the joints between them.
Redford recounts that the core of a pyramid would often be of locally-sourced limestone, whereas a superior quality of limestone (probably from Tura, less than 20 miles away on the opposite side of the Nile) was used for the pyramid’s outer layer to create a smooth, white finish that was visible from a great distance. On the pyramid’s apex, a capstone made from a harder stone such as granite could be covered with perhaps gold, silver, or similar, to reflect the sun.
But who actually built the pyramids? Who were the people that provided the labor force? According to Redford, the idea that the pyramids were built by slave labor is not correct. He claims that a complicated and legal system of indentured servitude existed in ancient Egypt, whereby peasants working on construction of the pyramids were given benefits like food, clothing and shelter and received “tax breaks”. It is estimated that the Great Pyramid construction utilized a workforce of between 20,000 and 30,000 of such laborers.
And how did the ancient Egyptians, with basic tools and only the most basic machinery, create such massive monuments in which even the separate building blocks were so huge – up to 70 tons each for the red granite blocks used in the King’s chamber in the very heart of the pyramid?
There are, as might be expected, differing opinions on the detail of how the huge task of construction was actually achieved. Redford states that the quarrying methods such as the way the stones were cut and transported are still the subject of study. There is said to be evidence that for quarrying the softer stones such as sandstone and limestone, those ancient Egyptian masons used chisels made of copper. However, for the harder materials like granite and diorite (a similar igneous rock to granite), Redford suggests that tools made from dolerite were used. Balls of dolerite – a rock harder than granite – were used by up to 60 0r 70 men to pound away at the bedrock, creating a trench around and under the granite to be removed as a building block, and then finally using huge wooden levers to break the block free. Alternatively, they would ram wooden wedges into slots cut into the rock, then fill the slots with water, covering the wedges. As the water expanded the wedges, the increased pressure would cause the block to split away from its bedrock.
Much of the granite used in the construction was extracted from quarries in Aswan, circa 500 miles away (upriver) to the south, as described in the article “Hard Stone Quarries”. Reddish granite blocks extracted in the quarries were manhandled and/or slid down to the river and onto barges for the journey to Giza.
Because we are discussing large and very heavy loads to be transported downriver, we might ask how was it actually done, without losing the precious stone cargo into the river, during loading or unloading or during the voyage itself? Franz Löhner in his article Building the Great Pyramid, suggests solutions for the loading, transportation and unloading of these large blocks of stone. He imagines the blocks were first hauled from the quarry to the bank of the Nile on sleds, then onto a ramp sloping down onto a raft, rigidly fixed between two barges to provide the necessary buoyancy from the three vessels and to avoid the raft tilting sideways as the block is slid onto it, with the aid of rope rolls installed on the raft to pull the block. See the Figure below showing such an arrangement, retrieved from Löhner’s article:
Because the journey north was against the prevailing wind, Löhner surmises that the barges would have had to drift downstream on the river’s current, guided by small rafts tied off the bows and rounded stones dragged over the river bed from the sterns, thus keeping the assembled crafts steered in the right direction. On arrival at Giza, a similar ramp arrangement to that used in the loading procedure would be used to unload the great block.
Once ashore at Giza, men and/or oxen teams then dragged the blocks over slipways prepared by lubricating them with oil, to reach the pyramid construction site. Redford describes a scene depicted in an Egyptian tomb where a 20 ft. alabaster figure was being dragged by 173 men pulling on four ropes while one man oiled the slipway.
The question many people ask is “How did they raise these huge blocks up to the heights required as construction progressed?” Redford believes that the workers built ramps of mud brick surfaced with plaster to provide a hard surface, then hauled the blocks up, again using the large numbers of men needed. He states that “If they consistently raised the ramp course-by-course as the teams dragged their blocks up, they could have gotten them into place fairly easily”. In support of this statement, Redford claims that one of these ramps is still in existence. He also goes on to say that he has been part of a group of 20 men pulling up a 2.5 ton block of granite at an archaeological dig, so he knows that it can be done.
Löhner suggests a slightly different solution, particularly when the height of the working level in the construction becomes significant. He thinks that several of the limestone blocks could have been used as counterweights when hauling the enormous granite stones up into position. For example, attaching (say) eight 5.6 ton limestone blocks by ropes to the front of a 50 ton granite block, then allowing them to slide down on tracks fitted on the opposite flank of the pyramid, would have drastically reduced the effort involved in raising the total of 90 of these heavy granite beams. Löhner’s article contains detailed drawings and explanations of this method. Also in his article, Löhner points out that for such a massive project there would have been what he calls “the building yard” – the place where the matters including the following would have had to be co-ordinated:
- Project control (sequence of the building, monitoring and controlling the pyramid’s shape, controlling nearby constructions, and so on);
- Assigning tasks to the large numbers of workers and work gangs;
- Manufacturing and maintaining, tracks, sledges, ropework, etc.;
- Making and maintaining tools;
- Organizing housing and supplies for the labor force.
There are differing opinions among scientists and scholars about some of the finer details of the construction; for example some think each of the circa 2.3 million stones were dressed on all faces before fitting in place on the pyramid, others think that only the underside would have been pre-dressed and the remaining faces dressed more or less in situ; i.e. when that particular block of stone had been raised up on the pyramid before final fitting.
Perhaps even more interesting is the recently emerging theory that some of the stones used in the construction were not natural limestone carved from quarries, but were cast, using reconstituted limestone bound with a form of cement which may be either silicon dioxide or a calcium and magnesium silicate of some description. This theory is reported by Sheila Berninger and Dorilona Rose (May 2007) in an article entitled: “The Surprising Truth About How the Great Pyramids Were Built”, published on a Live Science website.
The article reports that Professor Michel Barsoum of Drexel University and colleagues spent five years investigating the theory, and found indications that some of the blocks were indeed not natural limestone. He also surmised that this could explain why many of the pyramid’s stones fit so closely together with what appear to be precisely crafted joints. Barsoum also thinks that if the theory is confirmed, it could explain why no copper chisels have ever been found on the Giza plateau, even though it has always been believed that copper chisels would have been the tools available to work the limestone and sandstone blocks.
So far, the interior detail of the pyramids has not been discussed, save to mention that they were constructed as tombs for the pharaohs and their queens. The following drawing, retrieved from an article entitled The Secret Doors Inside the Great Pyramid by Zahi Hawass, shows the interior layout of the Great Pyramid:
As shown in the diagram, there are passageways, a King’s Chamber and a separate Queen’s Chamber, plus other features including a well shaft. The purposes of some of the detail features are still unknown. For instance, the so-called ventilation shafts don’t actually reach the outside of the pyramid.
- Conclusions
Though undoubtedly fantastic feats of construction that would even if newly-built today be impressive to say the very least, the pyramids nonetheless still hold secrets and mysteries yet to be unravelled. The research by Professor Barsoum suggests that to some extent the precision of the blocks can now be explained. However, the construction as a whole has to be viewed as magnificent – even awe-inspiring. The fact that to a large extent they have endured to this day is also testimony to the quality of their design and construction.
References
Building the Great Pyramid. Löhner, Franz. (2006). Retrieved from http://www.cheops-pyramide.ch/khufu-pyramid/nile-shipping.html
Hard Stone Quarries. Retrieved April 25, 2012, from http://www.duke.edu/~jpw5/quarries/hardstone.html
Penn State University (2008, March 28). How Were The Egyptian Pyramids Built? ScienceDaily. Retrieved April 25, 2012, from http://www.sciencedaily.com /releases/2008/03/080328104302.htm
The Egyptian Pyramid. Smithsonian Institution 1999 (revised 02/05). Department of Anthropology. Retrieved April 25, 2012, from http://www.si.edu/Encyclopedia_SI/nmnh/pyramid.htm
The Great Pyramid Controversy Part 2: The Big Deal. Omni Report website. Retrieved from http://theomnireport.blogspot.com/2011/03/part-2-great-pyramid-controversy-big.html
The Secret Doors Inside the Great Pyramid. Hawass, Zahi. Retrieved from http://guardians.net/hawass/articles/secret_doors_inside_the_great_pyramid.htm
The Surprising Truth About How the Great Pyramids Were Built. Berninger, Sheila and Rose, Dorilona. (May 2007). Live Science. Retrieved from http://www.livescience.com/1554-surprising-truth-great-pyramids-built.html
