Pyramids of Egypt


Originally the Great Pyramid was covered by casing stones that formed a smooth outer surface, and what is seen today is the underlying core structure. Some of the casing stones that once covered the structure can still be seen around the base. There have been varying scientific and alternative theories regarding the Great Pyramid's construction techniques. Most accepted construction hypotheses are based on the idea that it was built by moving huge stones from a quarry and dragging and lifting them into place.

There are three known chambers inside the Great Pyramid. The lowest chamber is cut into the bedrock upon which the pyramid was built and was unfinished. The so-called Queen's Chamber and King's Chamber are higher up within the pyramid structure. The Great Pyramid of Giza is the main part of a complex setting of buildings that included two mortuary temples in honor of Khufu (one close to the pyramid and one near the Nile), three smaller pyramids for Khufu's wives, an even smaller "satellite" pyramid, a raised causeway connecting the two temples, and small mastaba tombs surrounding the pyramid for nobles.

Building of the Great pyramid of Giza

It is believed the pyramid was built as a tomb for Fourth dynasty Egyptian pharaoh Khufu and constructed over a 14 to 20 year period. Khufu's vizier, Hemon, or Hemiunu, is believed by some to be the architect of the Great Pyramid.[3] It is thought that, at construction, the Great Pyramid was originally 280 Egyptian cubits tall, 146.478 metres (480.57 ft) but with erosion and absence of its pyramidion, its current height is 138.75 metres (455.22 ft). Each base side was 440 royal cubits, 230.37 metres (755.81 ft) in length. A royal cubit measures 0.524 meters.

The total mass of the pyramid is estimated at 5.9 million tonnes. The volume, including an internal hillock, is believed to be roughly 2,500,000 cubic meters.

Based on these estimates, building this in 20 years would involve installing approximately 800 tonnes of stone every day. The first precision measurements of the pyramid were done by Egyptologist Sir Flinders Petrie in 1880–82 and published as The Pyramids and Temples of Gizeh.

Almost all reports are based on his measurements. Many of the casing stones and interior chamber blocks of the Great Pyramid were fit together with extremely high precision. Based on measurements taken on the north eastern casing stones, the mean opening of the joints are only 0.5 millimeters wide (1/50th of an inch). The pyramid remained the tallest man-made structure in the world for over 3,800 years, unsurpassed until the 160-meter-tall spire of Lincoln Cathedral was completed c. 1300. The accuracy of the pyramid's workmanship is such that the four sides of the base have a mean error of only 58 millimeters in length

The base is horizontal and flat to within 21 mm. The sides of the square base are closely aligned to the four cardinal compass points (within 4 minutes of arc) based on true north, not magnetic north, and the finished base was squared to a mean corner error of only 12 seconds of arc.

The completed design dimensions, as suggested by Petrie's survey and later studies, are estimated to have originally been 280 cubits in height by 440 cubits in length at each of the four sides of its base. These proportions equate to p/2 to an accuracy of better than 0.05% (corresponding to the approximation of p as 22/7). Some Egyptologists consider this to have been the result of deliberate design proportion.

Verner wrote, "We can conclude that although the ancient Egyptians could not precisely define the value of p, in practice they used it". Petrie, author of Pyramids and Temples of Gizeh, who was the first accurate surveyor of Giza and the excavator and surveyor of the Pyramid of Meidum, concluded: "but these relations of areas and of circular ratio are so systematic that we should grant that they were in the builders design".

Earlier in the chapter he wrote more specifically, that: “We conclude therefore that the approximation of 7 to 22 as the ratio of diameter to circumference was recognised”.These proportions equated to the four outer faces sloping by 51.843° or 51° 50' 34?, which would have been understood and expressed by the Ancient Egyptians as a seked slope of 5˝ palms

Materials

The Great Pyramid consists of more than 2.3 million limestone blocks (unless it was built on a substantial core of natural rock, which is possible). The Egyptians obtained the majority of the limestone blocks from a nearby quarry. The Tura limestone used for the casing was quarried across the river. The largest granite stones in the pyramid, found in the "King's" chamber, weigh 25 to 80 tonnes and were transported more than 500 miles away from Aswan. Traditionally, ancient Egyptians cut stone blocks by hammering wedges into the stone which were then soaked with water. The wedges expanded, causing the rock to crack. Once they were cut, they were carried by boat either up or down the Nile River to the pyramid.

Casing stones

At completion, the Great Pyramid was surfaced by white 'casing stones' – slant-faced, but flat-topped, blocks of highly polished white limestone. These were carefully cut to what is approximately a face slope with a seked of 5 1/2 palms to give the required overall dimensions. Visibly, all that remains is the underlying stepped core structure seen today. In AD 1300, a massive earthquake loosened many of the outer casing stones, which were then carted away by Bahri Sultan An-Nasir Nasir-ad-Din al-Hasan in 1356 in order to build mosques and fortresses in nearby Cairo. The stones can still be seen as parts of these structures to this day. Later explorers reported massive piles of rubble at the base of the pyramids left over from the continuing collapse of the casing stones, which were subsequently cleared away during continuing excavations of the site. Nevertheless, a few of the casing stones from the lowest course can be seen to this day in situ around the base of the Great Pyramid, and display the same workmanship and precision as has been reported for centuries. Petrie also found a different orientation in the core and in the casing measuring 193 centimeters ± 25 centimeters. He suggested a redetermination of north was made after the construction of the core, but a mistake was made, and the casing was built with a different orientation.

Petrie related the precision of the casing stones as to being "equal to opticians' work of the present day, but on a scale of acres." and "to place such stones in exact contact would be careful work; but to do so with cement in the joints seems almost impossible.

Construction theories

Main article: Egyptian pyramid construction techniques

Many alternative, often contradictory, theories have been proposed regarding the Pyramid's construction techniques. Not all even agree that the blocks were quarried; Davidovits claims that they were cast in situ using a "limestone concrete", a theory which is rejected by other Egyptologists. The rest accept that it was built by moving huge stones from a quarry, being only unable to agree whether they were dragged, lifted or even rolled into place. The Greeks believed that slave labour was used but modern Egyptologists accept that it was built by many tens of thousands of skilled workers.

They camped near the pyramids and worked for a salary or as a form of paying taxes until the construction was completed.[citation needed] Their cemeteries were discovered in 1990 by archaeologists Zahi Hawass and Mark Lehner. Verner posited that the labor was organized into a hierarchy, consisting of two gangs of 100,000 men, divided into five zaa or phyle of 20,000 men each, which may have been further divided according to the skills of the workers.

One of the mysteries of the pyramid's construction is how they planned its construction. John Romer suggests that they used the same method that had been used for earlier and later constructions, laying out parts of the plan on the ground at a 1 to 1 scale. He writes that "such a working diagram would also serve to generate the architecture of the pyramid with a precision unmatched by any other means." He devotes a chapter of his book to the physical evidence that there was such a plan.

In fact, the Cole survey of 1925 discovered as part of some planning an actual Original Builder's Mark, engraved into the pavement perpendicular to the N face, suggesting definitely different slopes planned into the Pyramid E and W faces.

Interior

The original entrance to the Great Pyramid is 55' vertically about ground level and 24' east of the centre line of the pyramid. This was probably a measure to defeat any attempt to break into the pyramid. The efficacy of this ruse is proven by the presence of a Robbers Tunnel dug into the stonework on the centre line of the pyramid. This is the work of Caliph al-Mamun, whose men would have dug all the way through the pyramid without encountering anything had it not been for the unfortunate accident described below.

From this original entrance there is a Descending Passage 3'11" in height and 3'5" in width which goes down at an angle of 26° 31'23" through the masonry of the pyramid and then into the bedrock beneath it. After 345' the passage becomes level and continues for a further 29' to the lower Chamber, which appears not to have been finished. There is a continuation of the horizontal passage in the south wall of the lower chamber; there is also a pit dug in the floor of the chamber, which may represent a start at making the chamber deeper, or may have some ritual significance as a conduit to the pirmaeval waters under the earth.

Some Egyptologists suggest the Lower Chamber was intended to be the original burial chamber, but that King Khufu later changed his mind and wanted it to be higher up in the pyramid.

Egyptologist Bob Brier believes it was an insurance policy in case Khufu died early. When he was still alive and healthy after about 5 years of construction, the second (Queen's) chamber was begun. Sometime around the fifteenth year this chamber was also abandoned unfinished and the last or King's Chamber was built high up in the center of the pyramid.

33' from the entrance there is a square hole in the roof of the Descending Passage. This is the beginning of the Ascending Passage and was originally concealed with a slab of stone. The banging and thumping of al-Mamun's men dislodged this slab, which fell to the floor of the Descending Passage and slithered to the bottom of the sloping portion. The noise it made alerted the robbers that they needed to turn left.

The Ascending Passage is 129' long, as wide and high as the Descending Passage and slopes up at almost precisely the same angle. At the lower end the Ascending Passage is closed by three huge blocks of granite, each about 5' long. These appear to have been stored in the Grand Gallery - they are approximately an inch wider and higher than the entrance to the Ascending Passage - and released after the pharaoh's burial to slide down the Ascending Passage and permanently seal it. Once released, it would have been impossible to control the speed of descent of these granite blocks, so it is almost certain that they were released from above by workmen who would then have been shut in the pyramid.

At the start of the Grand Gallery on the right hand side there is a hole cut in the wall (and now blocked by chicken wire). This is the start of a vertical shaft which follows an irregular path through the masonry of the pyramid to join the Descending Passage. Almost certainly this was the escape route of these workmen and its roughness may indicate that it was constructed surreptitiously.

Also at the start of the Grand Gallery there is a Horizontal Passage leading to the so-called Queen's Chamber. The passage is 3'8" high for most of its length, but near the chamber there is a step in the floor, after which the passage is 5'8" high. In the left-hand wall of this Horizontal Passage there are two metal pipes sloping down at an angle. These were inserted by Japanese archaeologists who had previously used cosmic rays passing through the pyramid to expose x-ray film placed in the Lower Chamber, effectifely x-raying the pyramid. They discovered two anomalies suggestive of hidden chambers, but when they drilled down to these anomalies they found chambers one course high and completely filled with desert sand. It is thought that blocks of stone which failed to arrive in time for some reason were substituted for with the sand.

The Queen's Chamber is exactly half-way between the north and south faces of the pyramid and measures 18'10" north to south, 17'2" east to west and has a pointed roof with an apex 20'5" above the floor. At the eastern end of the chamber there is a niche 15'4" high, probably intended to house a statue of Khufu, though there is no sign of such a statue having been installed. The original depth of the niche was 3'5" but it has been deepened by treasure hunters.

In the north and south walls of the Queen's Chamber there are shafts. Unlike those in the King's Chamber, which immediately slope upwards, these are horizontal for over 6' before sloping upwards. The horizontal distance was cut in 1872 by a British engineer, Waynman Dixon, who believed on the analogy of the King's Chamber that such shafts must exist. He was proved right, but the fact that the shafts do not connect with the outer faces of the pyramid, nor with the Queen's Chamber leaves their purpose unknown. At the end of one of his shafts Dixon discovered a ball of black dioriate - almost certainly a "hammer" used to smooth the stonework - and a bronze implement of unknown purpose. Both objects are currently in the British Museum.

The shafts in the Queen's Chamber were explored in 1992 by the German engineer Rudolf Gantenbrink using a crawler robot of his own design which he called "Upuaut 2". He discovered that one of the shafts was blocked by limestone "doors" with two eroded copper handles. Unfortunately he issued a press release and in so doing fell foul of Zahi Hawass, who banned him from further work in Egypt. Some years later the National Geographic Society created a similar robot which drilled a small hole in the southern door, only to find another larger door behind it.

The northern passage, which was harder to navigate due to twists and turns, was also found to be blocked by a door.

The Grand Gallery continues the slope of the Ascending Passage, but is 28' high and 153' long. At the base it is 6'9" wide, but after 7'6" the blocks of stone in the walls are corbelled inwards by 3" on each side. There are seven of these steps, so at the top the Grand Gallery is only 3'5" wide. It is roofed by slaps of stone laid at a slightly steeper angle than the floor of the gallery, so that each stone fits into a slot cut in the top of the gallery like the teeth of a ratchet. The purpose was to have each block supported by the wall of the Gallery rather than resting on the block beneath it, which would have resulted in an unacceptable cumulative pressure at the lower end of the Gallery.

At the upper end of the Gallery on the right-hand side there is a hole near the roof which opens onto a short tunnel by means of which access can be gained to the lowest of the Relieving Chambers. The other Reliving Chambers were discovered in 1837/8 by Colonel Howard Vyse and J. S. Perring, who dug tunnels upwards using blasting powder.

The floor of the Grand Gallery consists of a shelf or step on either side, 1'8" wide, leaving a lower ramp 3'5" wide between them. In the shelves there are 54 slots, 27 on each side, matched by both vertical and horizontal slots in the walls of the Gallery (forming a cross shape rising out of the slot in the shelf). The purpose of these slots is not known, but the central gutter in the floor of the Gallery, which is the same width as the Ascending Passage, has led to speculation that the blocking stones were stored in the Grand Gallery and the slots held wooden beams to restrain them from sliding down the passage. This, in turn, has led to the proposal that originally many more than 3 blocking stones were intended, to completely fill the Ascending Passage.

At the top of the Grand Gallery there is a step giving onto a horizontal passage approximately 3'4" long, in which can be detected four slots, three of which were almost certainly intended to hold granite portcullises. Fragments of granite found by Petrie in the Descending Passage may have come from these now vanished doors.

The King's Chamber is 34'4" from east to west and 17'2" north to south. It has a flat roof 19'1" above the floor. 3' above the floor there is an "air shaft" in the north and south walls (one is now filled by an extractor fan to try to circulate air in the pyramid). The purpose of these shafts is not known: they appear to be aligned on stars, but on the other hand one of them follows a dog-leg course through the masonry, which would seem to spoil any benefit from celestial alignment. They do not appear to contribute to air circulation, so the most likely explanation is a ritual one.

The King's Chamber is entirely faced with granite, the blocks of stone being fitted with such precision that it is impossible to insert a piece of paper between them. Above the roof, which is formed of nine slabs of stone weighing in total about 400 tons, are five compartments known as Relieving Chambers. The first four, like the King's Chamber, have flat roofs formed by the floor of the chamber above, but the final chamber has a pointed roof. Vyse suspected the presence of upper chambers when he found that he could push a long reed through a crack in the ceiling of the first chamber. From lower to upper, the chambers are known as "Davidson Chamber", "Wellington Chamber", "Lady Arbuthnot's Chamber" and "Cambell's Chamber". It is believed that the compartments were intended to safeguard the King's Chamber from the possibility of a roof collapsing under the weight of stone above the Chamber. As the chambers were not intended to be seen, they were not finished in any way and a few of the stones still retain mason's marks painted on them. One of the stones in Cambell's Chamber bears a mark, apparently the name of a work gang, which incorporates the only reference in the pyramid to Pharaoh Khufu.

The only object in the King's Chamber is a rectangular granite sarcophagus, one corner of which is broken. The sarcophagus is slightly larger than the Ascending Passage, which indicates that it must have been placed in the Chamber before the roof was put in place. Unlike the fine masonry of the walls fo the Chamber, the sarcophagus is quite roughly finished, with saw marks visible in several places. This is in contrast with the finely finished and decorated sarophagi found in other pyramids of the same period. Petrie suggested that such a sarcophagus was intended but was lost in the river on the way north from Aswan and a hurriedly made replacement was used instead. This ingenious theory does not explain why the sarcophagus could not have been finished in situ.

Entrance

Today tourists enter the Great Pyramid via the Robbers' Tunnel dug by workmen employed by Caliph al-Ma'mun around AD 820. The tunnel is cut straight through the masonry of the pyramid for approximately 90', then turns sharply left to encounter the blocking stones in the Ascending Passage. Unable to remove these stones, the workmen tunnelled up beside them through the softer limestone of the Pyramid until they reached the Ascending Passage. It is possible to enter the Descending Passage from this point, but access is usually forbidden.

In recent years entrance to the pyramid has been restricted to groups of 100 morning and afternoon. As tickets are highly prized, those wishing to enter must queue outside the right ticket office for an hour or more before it opens. Under Zahi Hawass photography inside the pyramid is now strictly forbidden.

King's Chamber and the Golden Mean

At the end of the lengthy series of entrance ways leading into the interior is the structure's main chamber, the King's Chamber. This granite room was originally 10 × 20 × 11.4 cubits, or about 5.235 m × 10.47 m × 5.974 m comprising a double 10 × 10 cubit square floor, and a height equal to half the double square's diagonal. Some believed that the height was consistent with the geometric methods for determining the Golden Ratio f (phi) as the height is approximately phi times the width minus ˝, while phi can be derived from other dimensions of the pyramid, but evidence from Petrie’s surveys and later conclusions drawn by others shows that it was in fact the circular proportions that were deliberately incorporated into the internal and external designs of the Great Pyramid by its architects and builders, for symbolic reasons.

The so called golden ratio phi simply exists in the proportions of the architecture as an inadvertent by-product of the inclusion of the circular proportions. The reason for the inadvertent inclusion is that phi, the golden ratio, has a naturally occurring mathematical relation to the circular ratio pi that is unrelated to the architecture or geometry, and which was unknown to the pyramid's builders. Petrie confirmed that the King’s Chamber was a triumph of Egyptian geometry, the ratio of its length to the circuit of the side wall being the same as the ratio of 1 to pi, and that the exterior of the pyramid had been built to the same proportions

Pyramid complex

The Great Pyramid is surrounded by the usual complex of buildings. The Pyramid Temple, which stood on the east side of the pyramid and measured 171' north to south and 132' east to west, has almost entirely disappeared apart from the black basalt paving. There are only a few remnants of the causeway which linked the pyramid with the valley and the presumed Valley Temple which, if it exists, is buried beneath the village of Kafr es-Samman.

On the south side are the subsidiary pyramids, popularly known as Queens' Pyramids. Three remain standing to nearly full height but the fourth was so ruined that its existence was not suspected until the recent discovery of the first course of stones and the remains of the capstone. Herodotus claims that Khufu was a tyrant who prostituted his daughter in order to raise the money for building the Great Pyramid. She, however, requested a stone from each of her customers and used them to build her smaller pyramid. There is no evidence to support this tale (though it may reflect an arranged marriage advantageous for Khufu) and it is not certain that the Queens' Pyramids housed members of the court. Some have suggested that they corresponded to the later canopic jars for burial of the royal viscera - heart, lungs, liver and entrails.

Hidden beneath the paving around the pyramid was the tomb of Queen Hetepheres, sister-wife of Sneferu and mother of Khufu. Discovered by accident by the Reisner expedition, the burial was intact, though the carefully sealed coffin proved to be empty. Reisner suggests that Hetepheres was originally buried near her husband's pyramid but the tomb was robbed and the mummy destroyed. Khufu transferred the burial to his own pyramid complex, but the priests responsible for the burial did not dare tell him that his mother's body was missing.

There are three boat-shaped pits around the pyramid, of a size and shape to have held complete boats, though so shallow that any superstructure must have been removed or disassembled. It is not clear how these pits were sealed, as the span is rather too large for stone slabs, which may be why they were found empty apart from ropes and a few fragments of gilded wood found in one pit by Reisner. However in May, 1954, the Egyptian archaeologist Kamal el-Mallakh discovered a fourth pit, in shape a long, narrow rectangle, still covered by slabs of stone weighing up to 15 tons. Inside were 1224 pieces of wood, the longest 75' in length, the shortest 4". These were entrusted to a native boat builder, Haj Ahmed Yusuf, who slowly and methodically worked out how the pieces fit together. The entire process, including conservation and straightening of the warped wood, took fourteen years.

The result is a spectacular cedar-wood boat 143' long, its timbers held together by ropes. It is not clear how the boat was made water-tight. Early theories that soaking in water caused the wood to swell and thus become water-tight did not prove effective with the modern reconstruction "Horizon of Min" based on boats found in the Wadi Gawasis excavation and the reconstructers had recourse to traditional fibre caulking reinforced by beeswax. There is no sign of such measures on the Khufu boat, which may simply mean that the boat was never actually floated. The name "Djedefre", Khufu's son and successor, is found on some of the slabs of stone that sealed the pit, indicating that the boat was put there by Khufu's son.

The reconstructed boat is housed in a special boat-shaped, air-conditioned museum beside the pyramid. During construction of this museum, which stands above the boat pit, a second sealed boat pit was discovered. It was deliberately left unopened in the hope that future excavation techniques will allow more information to be recovered, however a hole was drilled in the sealing stones and air extracted from the pit in the hope of obtaining information about the ancient atmosphere. However as the air was found to be identical to modern air it was concluded that the pit is not hermetically sealed.

The Gizeh pyramid complex, which includes the pyramids of Khufu, Khafre and Menkaure, is surrounded by a cyclopaean stone wall, outside which Mark Lehner has discovered the town where the workers on the pyramids were housed. Among the discoveries are communal sleeping quarters, bakeries, breweries and kitchens (with evidence showing that bread and fish were staples of the diet), a hospital and a cemetery (where some of the skeletons were found with signs of trauma associated with accidents on a building site


The Great Pyramid of Giza (also called the Pyramid of Khufu and the Pyramid of Cheops) is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now El Giza, Egypt, and in a historical irony is the oldest of the Seven Wonders of the Ancient World and the only one that survives substantially intact. It is believed the pyramid was built as a tomb for fourth dynasty Egyptian Pharaoh Khufu (Cheops in Greek) and constructed over a 20 year period concluding around 2551 BC. The Great Pyramid was the tallest man-made structure in the world for over 3,800 years.