The Postcard
A postally unused carte postale that was published by the Cairo Postcard Trust. The card has a divided back.
The Great Sphinx of Giza
The Great Sphinx of Giza is a limestone statue of a reclining sphinx, a mythical creature with the head of a human, and the body of a lion.
Facing directly from west to east, it stands on the Giza Plateau on the west bank of the Nile. The face of the Sphinx appears to represent the pharaoh Khafre.
The original shape of the Sphinx was cut from the bedrock, and has since been restored with layers of limestone blocks.
It measures 73 m (240 ft) long from paw to tail, 20 m (66 ft) high from the base to the top of the head, and 19 m (62 ft) wide at its rear haunches.
Its nose was broken off for unknown reasons between the 3rd. and 10th. centuries AD.
The Sphinx is the oldest known monumental sculpture in Egypt, and one of the most recognisable statues in the world.
The archaeological evidence suggests that it was created by ancient Egyptians of the Old Kingdom during the reign of Khafre (c. 2558 - 2532 BC).
The Great Sphinx's Name
The commonly used name "Sphinx" was given to the monument in classical antiquity, about 2,000 years after the commonly accepted date of its construction by reference to a Greek mythological beast with the head of a woman, a falcon, a cat, or a sheep and the body of a lion with the wings of an eagle. (Although, like most Egyptian sphinxes, the Great Sphinx has a man's head and no wings).
The English word sphinx comes from the ancient Greek Σφίγξ from the verb σφίγγω (meaning to squeeze in English), after the Greek sphinx who strangled anyone who failed to answer her riddle.
History of the Great Sphinx
The Sphinx is a monolith carved from the bedrock of the plateau, which also served as the quarry for the pyramids and other monuments in the area.
Egyptian geologist Farouk El-Baz has suggested that the head of the Sphinx may have been carved first, out of a natural yardang, i.e. a ridge of bedrock that had been sculpted by the wind. These can sometimes achieve shapes which resemble animals.
El-Baz suggests that the "moat" or "ditch" around the Sphinx may have been quarried out later to allow for the creation of the full body of the sculpture.
The archaeological evidence suggests that the Great Sphinx was created around 2500 BC for the pharaoh Khafre, the builder of the Second Pyramid at Giza. The stones cut from around the Sphinx's body were used to construct a temple in front of it.
However, neither the enclosure nor the temple were ever completed, and the relative scarcity of Old Kingdom cultural material suggests that a Sphinx cult was not established at the time.
Selim Hassan, writing in 1949 on recent excavations of the Sphinx enclosure, made note of this circumstance:
"Taking all things into consideration, it seems that
we must give the credit of erecting this, the world's
most wonderful statue, to Khafre, but always with
this reservation: that there is not one single
contemporary inscription which connects the Sphinx
with Khafre, so sound as it may appear, we must treat
the evidence as circumstantial, until such time as a
lucky turn of the spade of the excavator will reveal to
the world a definite reference to the erection of the
Sphinx."
In order to construct the temple, the northern perimeter-wall of the Khafre Valley Temple had to be deconstructed, hence it follows that the Khafre funerary complex preceded the creation of the Sphinx and its temple.
Furthermore, the angle and location of the south wall of the enclosure suggests the causeway connecting Khafre's Pyramid and Valley Temple already existed before the Sphinx was planned. The lower base level of the Sphinx temple also indicates that it doesn't pre-date the Valley Temple.
The Great Sphinx in the New Kingdom
Some time around the First Intermediate Period, the Giza Necropolis was abandoned, and drifting sand eventually buried the Sphinx up to its shoulders.
The first documented attempt at an excavation dates to c. 1400 BC, when the young Thutmose IV gathered a team and, after much effort, managed to dig out the front paws. Between them he erected a shrine that housed the Dream Stele, an inscribed granite slab (possibly a re-purposed door lintel from one of Khafre's temples).
When the stele was discovered, its lines of text were already damaged and incomplete. An excerpt reads:
"... the royal son, Thothmos, being arrived, while
walking at midday and seating himself under the
shadow of this mighty god, was overcome by
slumber and slept at the very moment when Ra is
at the summit of heaven.
He found that the Majesty of this august god spoke
to him with his own mouth, as a father speaks to his
son, saying:
'Look upon me, contemplate me, O my son Thothmos;
I am thy father, Harmakhis-Khopri-Ra-Tum; I bestow
upon thee the sovereignty over my domain, the
supremacy over the living ... Behold my actual condition
that thou mayest protect all my perfect limbs. The sand
of the desert whereon I am laid has covered me. Save
me, causing all that is in my heart to be executed.'"
The Dream Stele associates the Sphinx with Khafre, however this part of the text is not entirely intact:
"... which we bring for him: oxen ... and all the young
vegetables; and we shall give praise to Wenofer ...
Khaf ... the statue made for Atum-Hor-em-Akhet."
Egyptologist Thomas Young, finding the Khaf hieroglyphs in a damaged cartouche used to surround a royal name, inserted the glyph ra to complete Khafre's name. However when the Stele was re-excavated in 1925, the lines of text referring to Khaf flaked off and were destroyed.
In the New Kingdom, the Sphinx became more specifically associated with the sun god Hor-em-akhet. Pharaoh Amenhotep II built a temple to the northeast of the Sphinx nearly 1000 years after its construction, and dedicated it to the cult of Hor-em-akhet.
The Great Sphinx in the Graeco-Roman Period
By Graeco-Roman times, Giza had become a tourist destination - the monuments were regarded as antiquities. Some Roman Emperors visited the Sphinx out of curiosity, and for political reasons.
The Sphinx was cleared of sand again in the first century AD in honour of Emperor Nero and the Governor of Egypt, Tiberius Claudius Balbilus.
A monumental stairway more than 12 metres (39 ft) wide was erected, leading to a pavement in front of the paws of the Sphinx. At the top of the stairs, a podium was positioned that allowed view into the Sphinx sanctuary.
Further back, another podium neighboured several more steps. The stairway was dismantled during the 1931–32 excavations by Émile Baraize.
Pliny the Elder described the face of the Sphinx being coloured red and gave measurements for the statue:
"In front of these pyramids is the Sphinx, a still more
wondrous object of art, but one upon which silence
has been observed, as it is looked upon as a divinity
by the people of the neighbourhood.
It is their belief that King Harmaïs was buried in it, and
they will have it that it was brought there from a distance.
The truth is, however, that it was hewn from the solid
rock; and, from a feeling of veneration, the face of the
monster is coloured red.
The circumference of the head, measured round the
forehead, is one hundred and two feet, the length of the
feet being one hundred and forty-three, and the height,
from the belly to the summit of the asp on the head,
sixty-two."
A stela dated to 166 AD commemorates the restoration of the retaining walls surrounding the Sphinx.
The last Emperor connected with the monument was Septimius Severus, around 200 AD. With the downfall of Roman power, the Sphinx was once more engulfed by the sands.
The Great Sphinx in the Middle Ages
Some ancient non-Egyptians saw the Sphinx as a likeness of the god Horon. The cult of the Sphinx continued into medieval times. The Sabians of Harran saw it as the burial place of Hermes Trismegistus.
Arab authors described the Sphinx as a talisman which guarded the area from the desert. Al-Maqrizi describes it as "The Talisman of the Nile" on which the locals believed the flood cycle depended.
Muhammad al-Idrisi stated that those wishing to obtain bureaucratic positions in the Egyptian government should give an incense offering to the monument.
Over the centuries, writers and scholars have recorded their impressions and reactions upon seeing the Sphinx. The vast majority were concerned with a general description, often including a mixture of science, romance and mystique. A typical description of the Sphinx by tourists and leisure travelers throughout the 19th. and 20th. century was made by John Lawson Stoddard:
"It is the antiquity of the Sphinx which thrills us as
we look upon it, for in itself it has no charms. The
desert's waves have risen to its breast, as if to
wrap the monster in a winding-sheet of gold. The
face and head have been mutilated by Moslem
fanatics. The mouth, the beauty of whose lips was
once admired, is now expressionless. Yet grand in
its loneliness, - veiled in the mystery of unnamed
ages, - the relic of Egyptian antiquity stands solemn
and silent in the presence of the awful desert -
symbol of eternity. Here it disputes with Time the
empire of the past; forever gazing on and on into
a future which will still be distant when we, like all
who have preceded us and looked upon its face,
have lived our little lives and disappeared."
From the 16th. century, European observers described the Sphinx having the face, neck and breast of a woman.
Most early Western images were book illustrations in print form, elaborated by a professional engraver from either previous images available, or some original drawing or sketch supplied by an author, and usually now lost.
Seven years after visiting Giza, André Thévet (Cosmographie de Levant, 1556) described the Sphinx as:
"The head of a colossus, caused to be
made by Isis, daughter of Inachus, then
so beloved of Jupiter".
He, or his artist and engraver, pictured it as a curly-haired monster with a grassy dog collar.
Athanasius Kircher (who never visited Egypt) depicted the Sphinx as a Roman statue (Turris Babel, 1679).
Johannes Helferich's (1579) Sphinx is a pinched-face, round-breasted woman with a straight-haired wig.
George Sandys stated in 1615 that the Sphinx was a harlot; Balthasar de Monconys interpreted the headdress as a kind of hairnet, while François de La Boullaye-Le Gouz's Sphinx had a rounded hairdo with bulky collar.
Richard Pococke's Sphinx was an adoption of Cornelis de Bruijn's drawing of 1698, featuring only minor changes, but is closer to the actual appearance of the Sphinx than anything previously drawn.
The print versions of Norden's drawings for his Voyage d'Egypte et de Nubie (1755) clearly show that the nose was missing.
Later Excavations
In 1817, the first modern archaeological dig, supervised by the Italian Giovanni Battista Caviglia, uncovered the Sphinx's chest completely.
In 1887, the chest, paws, the altar, and the plateau were all made visible. Flights of steps were unearthed, and finally accurate measurements were taken of the great figures.
The height from the lowest of the steps was found to be one hundred feet, and the space between the paws was found to be thirty-five feet long and ten feet wide. Here there was formerly an altar; and a stele of Thûtmosis IV was discovered, recording a dream in which he was ordered to clear away the sand that even then was gathering round the site of the Sphinx.
One of the people working on clearing the sands from around the Great Sphinx was Eugène Grébaut, a French Director of the Antiquities Service.
Opinions of Early Egyptologists
Early Egyptologists and excavators were divided regarding the age of the Sphinx and its associated temples.
In 1857, Auguste Mariette, founder of the Egyptian Museum in Cairo, unearthed the much later Inventory Stela (estimated to be from the Twenty-sixth Dynasty, c. 664 - 525 BC), which tells how Khufu came upon the Sphinx, already buried in sand.
Although certain tracts on the Stela are likely accurate, this passage is contradicted by archaeological evidence, thus considered to be Late Period historical revisionism, a purposeful fake, created by the local priests as an attempt to imbue the contemporary Isis temple with an ancient history it never had.
Such acts became common when religious institutions such as temples, shrines and priests' domains were fighting for political attention and for financial and economic donations.
Flinders Petrie wrote in 1883 regarding the state of opinion of the age of the Khafre Valley Temple, and by extension the Sphinx:
"The date of the Granite Temple has been so
positively asserted to be earlier than the fourth
dynasty, that it may seem rash to dispute the
point.
Recent discoveries, however, strongly show that
it was really not built before the reign of Khafre,
in the fourth dynasty."
Gaston Maspero, the French Egyptologist and second director of the Egyptian Museum in Cairo, conducted a survey of the Sphinx in 1886. He concluded that because the Dream Stela showed the cartouche of Khafre in line 13, it was he who was responsible for the excavation, and therefore the Sphinx must predate Khafre and his predecessors - possibly Fourth Dynasty, c. 2575 - 2467 BC. Maspero believed the Sphinx to be "the most ancient monument in Egypt".
Ludwig Borchardt attributed the Sphinx to the Middle Kingdom, arguing that the particular features seen on the Sphinx are unique to the 12th. dynasty, and that the Sphinx resembles Amenemhat III.
E. A. Wallis Budge agreed that the Sphinx predated Khafre's reign, writing in The Gods of the Egyptians (1904):
"This marvellous object was in existence in the
days of Khafre, or Khephren, and it is probable
that it is a very great deal older than his reign,
and that it dates from the end of the archaic
period [c. 2686 BC]."
Modern Dissenting Hypotheses
Rainer Stadelmann, former director of the German Archaeological Institute in Cairo, examined the distinct iconography of the nemes (headdress) and the now-detached beard of the Sphinx, and concluded that the style is more indicative of the pharaoh Khufu (2589–2566 BC).
He was known to the Greeks as Cheops, builder of the Great Pyramid of Giza and Khafre's father. Rainer supports this by suggesting Khafre's Causeway was built to conform to a pre-existing structure, which, he concludes, given its location, could only have been the Sphinx.
In 2004, Vassil Dobrev of the Institut Français d'Archéologie Orientale in Cairo announced that he had uncovered new evidence that the Great Sphinx may have been the work of the little-known pharaoh Djedefre (2528–2520 BC).
Djedefre was Khafra's half brother, and a son of Khufu. Dobrev suggests Djedefre built the Sphinx in the image of his father Khufu, identifying him with the sun god Ra in order to restore respect for their dynasty.
Dobrev also says that the causeway connecting Khafre's pyramid to the temples was built around the Sphinx, suggesting that it was already in existence at the time.
Egyptologist Nigel Strudwick responded to Dobrev by saying that:
"It is not implausible. But I would need more explanation,
such as why he thinks the pyramid at Abu Roash is a sun temple, something I'm sceptical about.
I have never heard anyone suggest that the name in the graffiti at Zawiyet el-Aryan mentions Djedefre.
I remain more convinced by the traditional argument of it being Khafre or the more recent theory of it being Khufu."
Recent Restorations of the Great Sphinx
In 1931, engineers of the Egyptian government repaired the head of the Sphinx. Part of its headdress had fallen off in 1926 due to erosion, which had also cut deeply into its neck. This questionable repair was by the addition of a concrete collar between the headdress and the neck, creating an altered profile.
Many renovations to the stone base and raw rock body were done in the 1980's, and then redone in the 1990's.
Natural and Deliberate Damage to the Great Sphinx
The limestone of the area consists of layers which offer differing resistance to erosion (mostly caused by wind and windblown sand), leading to the uneven degradation apparent in the Sphinx's body.
The lowest part of the body, including the legs, is solid rock. The body of the animal up to its neck is fashioned from softer layers that have suffered considerable disintegration. The layer from which the head was sculpted is much harder.
A number of "dead-end" shafts are known to exist within and below the body of the Great Sphinx, most likely dug by treasure hunters and tomb robbers.
The Great Sphinx's Missing Nose
Examination of the Sphinx's face shows that long rods or chisels were hammered into the nose area, one down from the bridge and another beneath the nostril, then used to pry the nose off towards the south, resulting in the one-metre wide nose still being lost to date.
Drawings of the Sphinx by Frederic Louis Norden in 1737 show the nose missing. Many folk tales exist regarding the destruction of its nose, aiming to provide an answer as to where it went or what happened to it.
One tale erroneously attributes it to cannonballs fired by the army of Napoleon Bonaparte. Other tales ascribe it to being the work of Mamluks. Since the 10th. century, some Arab authors have claimed it to be a result of iconoclastic attacks.
The Arab historian al-Maqrīzī, writing in the 15th. century, attributes the loss of the nose to Muhammad Sa'im al-Dahr, a Sufi Muslim who in 1378 found the local peasants making offerings to the Sphinx in the hope of increasing their harvest; he therefore defaced the Sphinx in an act of iconoclasm.
According to al-Maqrīzī, many people living in the area believed that the increased sand covering the Giza Plateau was retribution for al-Dahr's act of defacement.
Al-Minufi stated that the Alexandrian Crusade in 1365 was divine punishment for a Sufi sheikh breaking off the nose.
The Great Sphinx's Beard
In addition to the lost nose, a ceremonial pharaonic beard is thought to have been attached, although this may have been added in later periods after the original construction.
Egyptologist Vassil Dobrev has suggested that had the beard been an original part of the Sphinx, it would have damaged the chin of the statue upon falling. However the lack of visible damage supports his theory that the beard was a later addition.
The British Museum has limestone fragments which are thought to be from the Sphinx's beard.
Residues of red pigment are visible on areas of the Sphinx's face, and traces of yellow and blue pigment have also been found elsewhere on the Sphinx, leading Mark Lehner to suggest that:
"The monument was once decked
out in gaudy comic book colours".
However, as with the case of many ancient monuments, the pigments and colours have virtually disappeared, resulting in the yellow/beige appearance that the Sphinx has today.
Holes and Tunnels in the Great Sphinx
-- The Hole in the Sphinx's Head
Johann Helffrich visited the Sphinx during his travels in 1565 - 1566. He reports that a priest went into the head of the Sphinx, and when he spoke it was as if the Sphinx itself was speaking.
Many New Kingdom stelae depict the Sphinx wearing a crown. If it in fact existed, the hole could have been the anchoring point for it.
Émile Baraize closed the hole with a metal hatch in 1926.
-- Perring's Hole
Howard Vyse directed Perring in 1837 to drill a tunnel into the back of the Sphinx, just behind the head. The boring rods became stuck at a depth of 27 feet (8.2 m).
Attempts to blast the rods free caused further damage. The hole was cleared in 1978, and among the rubble was a fragment of the Sphinx's nemes headdress.
-- The Major Fissure
A major natural fissure in the bedrock cuts through the waist of the Sphinx. This was first excavated by Auguste Mariette in 1853.
The fissure measures up to 2 metres (6.6 ft) in width. In 1926 Baraize sealed the sides and roofed it with iron bars, limestone and cement. He then installed an iron trap door at the top. The sides of the fissure might have been artificially squared; however, the bottom is irregular bedrock, about 1 metre (3.3 ft) above the outside floor. A very narrow crack continues deeper.
-- The Rump Passage
When the Sphinx was cleared of sand in 1926 under direction of Baraize, it revealed an opening to a tunnel at floor-level on the north side of the rump. It was subsequently closed by masonry and nearly forgotten.
More than fifty years later, the existence of the passage was recalled by three elderly men who had worked during the sand clearing as basket carriers. This led to the rediscovery and excavation of the rump passage in 1980.
The passage consists of an upper and a lower section, which are angled roughly 90 degrees to each other. The upper part ascends to a height of 4 metres (13 ft) above the ground-floor at a northwest direction. It runs between masonry veneer and the core body of the Sphinx, and ends in a niche 1 metre (3.3 ft) wide and 1.8 metres (5.9 ft) high.
The ceiling of the niche consists of modern cement, which likely spilled down from the filling of the gap between masonry and core bedrock, some 3 metres (9.8 ft) above.
The lower part descends steeply into the bedrock towards the northeast, for a distance of approximately 4 metres (13 ft) and a depth of 5 metres (16 ft). It terminates in a pit at groundwater level.
At the entrance it is 1.3 metres (4.3 ft) wide, narrowing to about 1.07 metres (3.5 ft) towards the end. Among the sand and stone fragments, a piece of tin foil and the base of a modern ceramic water jar was found.
The clogged bottom of the pit contained modern fill. Among it, more tin foil, modern cement and a pair of shoes.
It is possible that the entire passage was cut top down, beginning high up on the rump, and that the current access point at floor-level was made at a later date.
Vyse noted in his diary in 1837 that he was "boring" near the tail, which indicates him as the creator of the passage, as no other tunnel has been identified at this location. Another interpretation is that the shaft is of ancient origin, perhaps an exploratory tunnel or an unfinished tomb shaft.
-- The Niche in the Northern Flank
There is a niche in the Sphinx's core body. It was closed during the 1925-6 restorations.
-- The Space Behind the Dream Stele
The space behind the Dream Stele, between the paws of the Sphinx, was covered by an iron beam and cement roof and then fitted with an iron trap door.
-- The Keyhole Shaft
At the ledge of the Sphinx enclosure there is a square shaft opposite the northern hind paw. It was cleared during excavation in 1978 and measures 1.42 by 1.06 metres (4.7 by 3.5 ft) and about 2 metres (6.6 ft) deep.
Lehner interpreted the shaft to be an unfinished tomb, and named it the "Keyhole Shaft", because a cutting in the ledge above the shaft is shaped like the lower part of a keyhole, upside down.
The Great Pyramid of Giza
The Great Pyramid of Giza is the largest Egyptian pyramid, and the tomb of the Fourth Dynasty pharaoh Khufu. Built in the 26th. century BC during a period of around 27 years, it is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact.
Initially standing at 146.6 metres (481 feet), the Great Pyramid was the tallest man-made structure in the world for more than 3,800 years. Over time, most of the smooth white limestone casing was removed, which lowered the pyramid's height to the present 138.5 metres (454.4 ft).
What is seen today is the underlying core structure. The base was measured to be 230.3 metres (755.6 ft) square, giving a volume of roughly 2.6 million cubic metres (92 million cubic feet).
The Great Pyramid was built by quarrying an estimated 2.3 million large blocks weighing 6 million tonnes in total. The majority of stones are not uniform in size or shape, and are only roughly dressed.
The outside layers were bound together by mortar. Primarily local limestone from the Giza Plateau was used. Other blocks were imported by boat down the Nile: white limestone from Tura for the casing, and granite blocks from Aswan, weighing up to 80 tonnes, for the King's Chamber.
There are three known chambers inside the Great Pyramid. The lowest was cut into the bedrock, but it remained unfinished. The Queen's Chamber and the King's Chamber, that contains a granite sarcophagus, are higher up, within the pyramid structure.
Khufu's vizier, Hemiunu, is believed to be the architect of the Great Pyramid. Many varying scientific and alternative hypotheses attempt to explain the exact construction techniques.
Attribution to Khufu
Historically the Great Pyramid has been attributed to Khufu based on the words of authors of classical antiquity, first and foremost Herodotus and Diodorus Siculus.
However, during the middle ages a number of other people were credited with the construction of the pyramid, for example Joseph, Nimrod or King Saurid.
In 1837 four additional Relieving Chambers were found above the King's Chamber after tunneling to them. The chambers, previously inaccessible, were covered in hieroglyphs of red paint.
The workers who were building the pyramid had marked the blocks with the names of their gangs, which included the pharaoh's name (e.g.: “The gang, The white crown of Khnum-Khufu is powerful”).
The names of Khufu were spelled out on the walls over a dozen times. Another of these graffiti was found by Goyon on an exterior block of the 4th layer of the pyramid.
Throughout the 20th. century the cemeteries next to the pyramid were excavated. Family members and high officials of Khufu were buried there. Most notably the wives, children and grandchildren of Khufu, along with the funerary cache of Hetepheres I, mother of Khufu.
As Hassan puts it:
"From the early dynastic times, it was always the
custom for the relatives, friends and courtiers to
be buried in the vicinity of the king they had served
during life. This was quite in accordance with the
Egyptian idea of the Hereafter."
The cemeteries were actively expanded until the 6th. dynasty, but used less frequently afterwards. The earliest pharaonic name of seal impressions is that of Khufu, the latest of Pepi II.
Worker graffiti was written on some of the stones of the tombs as well; for instance, "Mddw" (Horus name of Khufu) on the mastaba of Chufunacht, probably a grandson of Khufu.
In 1954 two boat pits, one containing the Khufu ship, were discovered buried at the south foot of the pyramid. The cartouche of Djedefre was found on many of the blocks that covered the boat pits. As the successor and eldest son he would have presumably been responsible for the burial of Khufu.
The second boat pit was examined in 1987; excavation work started in 2010. Graffiti on the stones included 4 instances of the name "Khufu", 11 instances of "Djedefre", a year (in reign, season, month and day), measurements of the stone, various signs and marks, and a reference line used in construction, all done in red or black ink.
During excavations in 2013 the Diary of Merer in the form of rolls of papyrus was found at Wadi al-Jarf. It documents the transportation of white limestone blocks from Tura to the Great Pyramid, which is mentioned by its original name Akhet Khufu dozens of times.
The diary records that the stones were accepted at She Akhet-Khufu ("The pool of the pyramid Horizon of Khufu") and Ro-She Khufu (“The entrance to the pool of Khufu”) which were under supervision of Ankhhaf, half brother and vizier of Khufu, as well as owner of the largest mastaba of the Giza East Field.
The Age of the Great Pyramid
The age of the Great Pyramid has been determined by two principal approaches:
-- Indirectly, through its attribution to Khufu and his chronological age, based on archaeological and textual evidence.
-- Directly, via radiocarbon dating of organic material found in the pyramid and included in its mortar. Mortar was used generously in the Great Pyramid's construction. In the mixing process, ashes from fires were added to the mortar, organic material that could be extracted and radiocarbon dated.
A total of 46 samples of the mortar were taken in 1984 and 1995, making sure they were clearly inherent to the original structure and could not have been incorporated at a later date.
The results were calibrated to 2871–2604 BC. A reanalysis of the data gave a completion date for the pyramid between 2620 and 2484 BC.
In 1872 Waynman Dixon opened the lower pair of air-shafts that were previously closed at both ends by chiseling holes into the walls of the Queen's Chamber.
One of the objects found within was a cedar plank, which came into possession of James Grant, a friend of Dixon. After inheritance it was donated to the Museum of Aberdeen in 1946. However it had broken into pieces, and was filed incorrectly.
Lost in the vast museum collection, it was only rediscovered in 2020, when it was radiocarbon dated to 3341–3094 BC. Being over 500 years older than Khufu's chronological age, Abeer Eladany suggests that the wood originated from the center of a long-lived tree, or had been recycled for many years prior to being deposited in the pyramid.
Construction of the Great Pyramid of Giza
-- Preparation of the Site
A hillock forms the base on which the pyramid stands. It was cut back into steps, and only a strip around the perimeter was leveled. Using modern equipment, this has been measured to be horizontal and flat to within 21 millimetres (0.8 in).
The bedrock reaches a height of almost 6 metres (20 ft) above the pyramid base at the location of the Grotto.
Along the sides of the base platform a series of holes are cut in the bedrock. Lehner hypothesizes that they held wooden posts used for alignment.
Edwards, among others, has suggested that water was used in order to level the base, although it is unclear how workable such a system would be.
-- Materials
The Great Pyramid consists of an estimated 2.3 million blocks. Approximately 5.5 million tonnes of limestone, 8,000 tonnes of granite, and 500,000 tonnes of mortar were used in the construction.
Most of the blocks were quarried at Giza just south of the pyramid, an area now known as the Central Field.
The white limestone used for the casing originated from Tura 10 km (6.2 mi) south of Giza), and was transported by boat down the Nile.
The granite stones in the pyramid were transported from Aswan, more than 900 km (560 mi) away. The largest, weighing up to 80 tonnes, forms the roofs of the King's Chamber.
Ancient Egyptians cut stone into rough blocks by hammering grooves into natural stone faces, inserting wooden wedges, then soaking these with water. As the water was absorbed, the wedges expanded, breaking off workable chunks. Once the blocks were cut, they were carried by boat either up or down the Nile River to the pyramid.
-- The Workforce
The Greeks believed that slave labour was used, but modern discoveries made at nearby workers' camps associated with construction at Giza suggest that it was built instead by thousands of conscript laborers.
Worker graffiti found at Giza suggest haulers were divided into groups of 40 men, consisting of four sub-units that each had an "Overseer of Ten".
As to the question of how over two million blocks could have been cut within Khufu's lifetime, stonemason Franck Burgos conducted an archaeological experiment based on an abandoned quarry of Khufu discovered in 2017.
Within it, an almost completed block and the tools used for cutting it had been uncovered: hardened arsenic copper chisels, wooden mallets, ropes and stone tools. In the experiment, replicas of these were used to cut a block weighing about 2.5 tonnes (the average block size used for the Great Pyramid).
It took 4 workers 4 days (with each working 6 hours a day) to excavate it. The initially slow progress sped up six times when the stone was wetted with water.
Based on the data, Burgos extrapolates that about 3,500 quarry-men could have produced the 250 blocks per day needed to complete the Great Pyramid within 27 years.
A construction management study conducted in 1999, in association with Mark Lehner and other Egyptologists, has estimated that the total project required an average workforce of about 13,200 individuals, with a peak workforce of roughly 40,000.
Surveys and Design of the Great Pyramid
The first precise measurements of the pyramid were made by Egyptologist Flinders Petrie in 1880–1882, published as The Pyramids and Temples of Gizeh.
Many of the casing-stones and inner chamber blocks of the Great Pyramid fit together with high precision, with joints, on average, only 0.5 millimetres (0.020 in) wide. On the contrary, core blocks were only roughly shaped, with rubble inserted between larger gaps. Mortar was used to bind the outer layers together and to fill gaps and joints.
The block height and weight tends to get progressively smaller towards the top. Petrie measured the lowest layer to be 148 centimetres (4.86 ft) high, whereas the layers towards the summit barely exceed 50 centimetres (1.6 ft).
The accuracy of the pyramid's perimeter is such that the four sides of the base have an average error of only 58 millimetres (2.3 inches) in length, and the finished base was squared to a mean corner error of only 12 seconds of arc.
Ancient Egyptians used seked - how much length for one cubit of rise - to describe slopes. For the Great Pyramid a seked of 5+ palms was chosen, a ratio of 14 up to 11 in.
Some Egyptologists suggest this slope was chosen because the ratio of perimeter to height (1760/280 cubits) equals 2π to an accuracy of better than 0.05 percent (corresponding to the well-known approximation of π as 22/7).
Verner wrote:
"We can conclude that although the ancient
Egyptians could not precisely define the value
of π, in practice they used it.
"These relations of areas and of circular ratio
are so systematic that we should grant that
they were in the builder's design".
Alignment to the Cardinal Directions
The sides of the Great Pyramid's base are closely aligned to the four geographic (not magnetic) cardinal directions, deviating on average 3 minutes and 38 seconds of arc. Several methods have been proposed for how the ancient Egyptians achieved this level of accuracy:
-- The Solar Gnomon Method: the shadow of a vertical rod is tracked throughout a day. The shadow line is intersected by a circle drawn around the base of the rod. Connecting the intersecting points produces an east-west line.
An experiment using this method resulted in lines being, on average, 2 minutes, 9 seconds off due east–west. Employing a pinhole produced much more accurate results (19 arc seconds off), whereas using an angled block as a shadow definer was less accurate (3′ 47″ off).
-- The Pole Star Method: the polar star is tracked using a movable sight and fixed plumb line. Halfway between the maximum eastern and western elongations is true north.
Thuban, the polar star during the Old Kingdom, was about two degrees removed from the celestial pole at the time.
-- The Simultaneous Transit Method: the stars Mizar and Kochab appear on a vertical line on the horizon, close to true north around 2500 BC. They slowly and simultaneously shift east over time, which is used to explain the relative misalignment of the pyramids.
Construction Theories
Many alternative, often contradictory, theories have been proposed regarding the pyramid's construction. One mystery of the pyramid's construction is its planning. John Romer suggests that they used the same method that had been used for earlier and later constructions, i.e. 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
precision unmatched by any other means".
The basalt blocks of the pyramid temple show clear evidence of having been cut with some kind of saw with an estimated cutting blade of 15 feet (4.6 m) in length. Romer suggests that this "super saw" may have had copper teeth and weighed up to 140 kilograms (310 lb).
He theorizes that such a saw could have been attached to a wooden trestle support, and possibly used in conjunction with vegetable oil, cutting sand, emery or pounded quartz to cut the blocks, which would have required the labour of at least a dozen men to operate it.
The Exterior Casing
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At completion, the Great Pyramid was cased entirely in white limestone. There is a casing stone from the Great Pyramid in the British Museum.
Precisely worked blocks were placed in horizontal layers and carefully fitted together with mortar, their outward faces cut at a slope and smoothed to a high degree. Together they created four uniform surfaces, angled at 51°50'40.
Unfinished casing blocks of the pyramids of Menkaure and Henutsen at Giza suggest that the front faces were smoothed only after the stones were laid, with chiseled seams marking correct positioning, and where the superfluous rock would have to be trimmed off.
An irregular pattern is noticeable when looking at the pyramid's layers in sequence, where layer height declines steadily only to rise sharply again.
"Backing stones" supported the casing which were (unlike the core blocks) precisely dressed, and bound to the casing with mortar. These stones give the structure its visible appearance, following the dismantling of the pyramid in the middle ages.
In 1303 AD, a massive earthquake loosened many of the outer casing stones, which were said to have been carted away by Bahri Sultan An-Nasir Nasir-ad-Din al-Hasan in 1356 for use in nearby Cairo.
Many more casing stones were removed from the site by Muhammad Ali Pasha in the early 19th. century to build the upper portion of his Alabaster Mosque in Cairo.
Later explorers reported massive piles of rubble at the base of the pyramid left over from the continuing collapse of the casing stones, which were subsequently cleared away during continuing excavations of the site.
Today a few of the casing stones from the lowest course can be seen in situ on each side, with the best preserved on the north below the entrances, excavated by Vyse in 1837.
The mortar was chemically analyzed and contains organic inclusions (mostly charcoal), samples of which were radiocarbon dated to 2871–2604 BC. It has been theorized that the mortar enabled the masons to set the stones exactly by providing a level bed.
The Missing Pyramidion
The pyramid was once topped by a capstone known as a pyramidion. The material it was made from is subject to much speculation; limestone, granite or basalt are commonly proposed, while in popular culture it is often said to be solid gold or gilded.
All known 4th. dynasty pyramidia (of the Red Pyramid, the Satellite Pyramid of Khufu and the Queen's Pyramid of Menkaure are of white limestone, and were not gilded.
Only from the 5th. dynasty onward is there evidence of gilded capstones.
The Great Pyramid's pyramidion was already lost in antiquity, as Pliny the Elder and later authors report of a platform on its summit. Nowadays the pyramid is about 8 metres (26 ft) shorter than it was when intact, with about 1,000 tonnes of material missing from the top.
In 1874 a mast was installed on the top of the pyramid by the Scottish astronomer Sir David Gill who, whilst returning from work involving observing a rare Venus transit, was invited to survey Egypt. He began by surveying the Great Pyramid.
His measurements of the pyramid were accurate to within 1mm, and the survey mast is still in place to this day.
Interior of the Great Pyramid
The internal structure consists of three main chambers (the King's-, Queen's- and Subterranean Chamber), the Grand Gallery and various corridors and shafts.
There are two entrances into the pyramid; the original and a forced passage, which meet at a junction. From there, one passage descends into the Subterranean Chamber, while the other ascends to the Grand Gallery. From the beginning of the gallery three paths can be taken:
(a) A vertical shaft that leads down, past a grotto, to meet the descending passage.
(b) A horizontal corridor leading to the Queen's Chamber.
(c) A path up the gallery itself to the King's Chamber that contains the sarcophagus.
Both the King's and Queen's Chamber have a pair of small "air-shafts". Above the King's Chamber are a series of five Relieving Chambers.
--The Original Entrance
The original entrance is located on the north side, 15 royal cubits (7.9 m; 25.8 ft) east of the center-line of the pyramid. Before the removal of the casing in the middle ages, the pyramid was entered through a hole in the 19th. layer of masonry, approximately 17 metres (56 ft) above the pyramid's base level.
The height of that layer – 96 centimetres (3.15 ft) – corresponds to the size of the entrance tunnel which is commonly called the Descending Passage. According to Strabo (64–24 BC) a movable stone could be raised to enter this sloping corridor, however it is not known if it was a later addition or original.
A row of double chevrons diverts weight away from the entrance. Several of these chevron blocks are now missing, as the slanted faces they used to rest on indicate.
Numerous, mostly modern, graffiti is cut into the stones around the entrance. Most notable is a large, square text of hieroglyphs carved in honor of Frederick William IV, by Karl Richard Lepsius's Prussian expedition to Egypt in 1842.
-- The North Face Corridor
In 2016 the ScanPyramids team detected a cavity behind the entrance chevrons using muography, which was confirmed in 2019 to be a corridor at least 5 metres (16 ft) long, running horizontal or sloping upwards. Whether or not it connects to the Big Void above the Grand Gallery remains to be seen.
-- The Robbers' Tunnel
Today tourists enter the Great Pyramid via the Robbers' Tunnel, which was long ago cut straight through the masonry of the pyramid. The entrance was forced into the 6th. and 7th. layer of the casing, about 7 metres (23 ft) above the base.
After running more-or-less straight and horizontal for 27 metres (89 ft) it turns sharply left to encounter the blocking stones in the Ascending Passage. It is possible to enter the Descending Passage from this point, but access is usually forbidden.
The origin of this Robbers' Tunnel is the subject of much discussion. According to tradition, the tunnel was excavated around 820 AD by Caliph al-Ma'mun's workmen with a battering ram.
The digging dislodged the stone in the ceiling of the Descending Passage which hid the entrance to the Ascending Passage, and the noise of that stone falling then sliding down the Descending Passage alerted them to the need to turn left.
Unable to remove these stones, the workmen tunneled up beside them through the softer limestone of the Pyramid until they reached the Ascending Passage.
Due to a number of historical and archaeological discrepancies, many scholars contend that this story is apocryphal. They argue that it is much more likely that the tunnel had been carved shortly after the pyramid was initially sealed.
This tunnel, the scholars argue, was then resealed (likely during the Ramesside Restoration), and it was this plug that al-Ma'mun's ninth-century expedition cleared away. This theory is furthered by the report of patriarch Dionysius I Telmaharoyo, who claimed that before al-Ma'mun's expedition, there already existed a breach in the pyramid's north face that extended into the structure 33 metres (108 ft) before hitting a dead end.
This suggests that some sort of robber's tunnel predated al-Ma'mun, and that the caliph simply enlarged it and cleared it of debris.
-- The Descending Passage
From the original entrance, a passage descends through the masonry of the pyramid and then into the bedrock beneath it, ultimately leading to the Subterranean Chamber.
It has a slanted height of 4 Egyptian feet (1.20 m; 3.9 ft) and a width of 2 cubits (1.0 m; 3.4 ft). Its angle of 26°26'46" corresponds to a ratio of 1 to 2 (rise over run).
After 28 metres (92 ft), the lower end of the Ascending Passage is reached; a square hole in the ceiling, which is blocked by granite stones and might have originally been concealed.
To circumvent these hard stones, a short tunnel was excavated that meets the end of the Robbers' Tunnel. This was expanded over time and fitted with stairs.
The passage continues to descend for another 72 metres (236 ft), now through bedrock instead of the pyramid superstructure.
Lazy guides used to block off this part with rubble in order to avoid having to lead people down and back up the long shaft, until around 1902 when Covington installed a padlocked iron grill-door to stop this practice.
Near the end of this section, on the west wall, is the connection to the vertical shaft that leads up to the Grand Gallery.
A horizontal shaft connects the end of the Descending Passage to the Subterranean Chamber, It has a length of 8.84 m (29.0 ft), width of 85 cm (2.79 ft) and height of 91–95 cm (2.99–3.12 ft).
-- The Subterranean Chamber
The Subterranean Chamber, or "Pit", is the lowest of the three main chambers, and the only one dug into the bedrock beneath the pyramid.
Located about 27 m (89 ft) below base level, it measures roughly 16 cubits (8.4 m; 27.5 ft) north-south by 27 cubits (14.1 m; 46.4 ft) east-west, with an approximate height of 4 m (13 ft).
The western half of the room, apart from the ceiling, is unfinished, with trenches left behind by the quarry-men running east to west. The only access, through the Descending Passage, lies on the eastern end of the north wall.
Although seemingly known in antiquity, according to Herodotus and later authors, its existence had been forgotten in the middle ages until rediscovery in 1817, when Giovanni Caviglia cleared the rubble blocking the Descending Passage.
Opposite the entrance, a blind corridor runs straight south for 11 m (36 ft) and continues at a slight angle for another 5.4 m (18 ft), measuring about 0.75 m (2.5 ft) squared. A Greek or Roman character was found on its ceiling, suggesting that the chamber had indeed been accessible during Classical antiquity.
In the middle of the eastern half, there is a large hole called Pit Shaft or Perring's Shaft. The upmost part may have ancient origins, about 2 m (6.6 ft) squared in width, and 1.5 m (4.9 ft) in depth. Caviglia and Salt enlarged it to the depth of about 3 m (9.8 ft).
In 1837 Vyse directed the shaft to be sunk to a depth of 50 ft (15 m), in hopes of discovering the chamber encompassed by water that Herodotus alludes to. However no chamber was discovered after Perring and his workers had spent one and a half years penetrating the bedrock to the then water level of the Nile, some 12 m (39 ft) further down.
The rubble produced during this operation was deposited throughout the chamber. Petrie, visiting in 1880, found the shaft to be partially filled with rainwater that had rushed down the Descending Passage. In 1909, when the Edgar brothers' surveying activities were encumbered by the material, they moved the sand and smaller stones back into the shaft. The deep, modern shaft is sometimes mistaken to be part of the original design.
-- The Ascending Passage
The Ascending Passage connects the Descending Passage to the Grand Gallery. It is 75 cubits (39.3 m; 128.9 ft) long, and of the same width and height as the shaft it originates from, although its angle is slightly lower at 26°6'.
The lower end of the shaft is plugged by three granite stones, which were slid down from the Grand Gallery to seal the tunnel. The uppermost stone is heavily damaged.
The end of the Robbers' Tunnel concludes slightly below the stones, so a short tunnel was dug around them to gain access to the Descending Passage.
-- The Well Shaft and Grotto
The Well Shaft (also known as the Service Shaft or Vertical Shaft) links the lower end of the Grand Gallery to the bottom of the Descending Passage, about 50 metres (160 ft) further down.
It takes a winding and indirect course. The upper half goes through the nucleus masonry of the pyramid. It runs vertical at first for 8 metres (26 ft), then slightly angled southwards for about the same distance, until it hits bedrock approximately 5.7 metres (19 ft) above the pyramid's base level.
Another vertical section descends further, which is partially lined with masonry that has been broken through to a cavity known as the Grotto. The lower half of the Well Shaft goes through the bedrock at an angle of about 45° for 26.5 metres (87 ft) before a steeper section, 9.5 metres (31 ft) long, leads to its lowest point. The final section of 2.6 metres (8.5 ft) connects it to the Descending Passage, running almost horizontal. The builders evidently had trouble aligning the lower exit.
The purpose of the shaft is commonly explained as a ventilation shaft for the Subterranean Chamber, and as an escape shaft for the workers who slid the blocking stones of the Ascending Passage into place.
The Grotto is a natural limestone cave that was likely filled with sand and gravel before construction, before being hollowed out by looters. A granite block rests in it that probably originated from the portcullis that once sealed the King's Chamber.
-- The Queen's Chamber
The Horizontal Passage links the Grand Gallery to the Queen's Chamber. Five pairs of holes at the start suggest the tunnel was once concealed with slabs that laid flush with the gallery floor. The passage is 2 cubits (1.0 m; 3.4 ft) wide and 1.17 m (3.8 ft) high for most of its length, but near the chamber there is a step in the floor, after which the passage increases to 1.68 m (5.5 ft) high.
The Queen's Chamber is exactly halfway between the north and south faces of the pyramid. It measures 10 cubits (5.2 m; 17.2 ft) north-south, 11 cubits (5.8 m; 18.9 ft) east-west,[146] and has a pointed roof that apexes at 12 cubits (6.3 m; 20.6 ft) tall.
At the eastern end of the chamber there is a niche 9 cubits (4.7 m; 15.5 ft) high. The original depth of the niche was 2 cubits (1.0 m; 3.4 ft), but it has since been deepened by treasure hunters.
Shafts were discovered in the north and south walls of the Queen's Chamber in 1872 by British engineer Waynman Dixon, who believed shafts similar to those in the King's Chamber must also exist. The shafts were not connected to the outer faces of the pyramid, and their purpose is unknown.
In one shaft Dixon discovered a ball of diorite, a bronze hook of unknown purpose and a piece of cedar wood. The first two objects are currently in the British Museum. The latter was lost until recently when it was found at the University of Aberdeen.
The northern shaft's angle of ascent fluctuates, and at one point turns 45 degrees to avoid the Great Gallery. The southern shaft is perpendicular to the pyramid's slope.
The shafts in the Queen's Chamber were explored in 1993 by the German engineer Rudolf Gantenbrink using a crawler robot he designed, called Upuaut 2.
After a climb of 65 m (213 ft), he discovered that one of the shafts was blocked by a limestone "door" with two eroded copper "handles".
The National Geographic Society created a similar robot which, in September 2002, drilled a small hole in the southern door, only to find another stone slab behind it. The northern passage, which was difficult to navigate because of its twists and turns, was also found to be blocked by a slab.
Research continued in 2011 with the Djedi Project which used a fibre-optic "micro snake camera" that could see around corners. With this, they were able to penetrate the first door of the southern shaft through the hole drilled in 2002, and view all the sides of the small chamber behind it.
They discovered hieroglyphics written in red paint. Egyptian mathematics researcher Luca Miatello stated that the markings read "121" – the length of the shaft in cubits.
The Djedi team were also able to scrutinize the inside of the two copper "handles" embedded in the door, which they now believe to be for decorative purposes. They additionally found the reverse side of the "door" to be finished and polished, which suggests that it was not put there just to block the shaft from debris, but rather for a more specific reason.
-- The Grand Gallery
The Grand Gallery continues the slope of the Ascending Passage towards the King's Chamber, extending from the 23rd. to the 48th. course, a rise of 21 metres (69 ft). It has been praised as a truly spectacular example of stonemasonry.
It is 8.6 metres (28 ft) high and 46.68 metres (153.1 ft) long. The base is 4 cubits (2.1 m; 6.9 ft) wide, but after two courses - at a height of 2.29 metres (7.5 ft) - the blocks of stone in the walls are corbelled inwards by 6–10 centimetres (2.4–3.9 in) on each side.
There are seven of these steps, so, at the top, the Grand Gallery is only 2 cubits (1.0 m; 3.4 ft) wide. It is roofed by slabs of stone laid at a slightly steeper angle than the floor so that each stone fits into a slot cut into 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, in order to prevent cumulative pressure.
At the upper end of the Gallery, on the eastern wall, there is a hole near the roof that opens into a short tunnel by which access can be gained to the lowest of the Relieving Chambers.
At the top of the gallery, there is a step onto a small horizontal platform where a tunnel leads through the Antechamber, once blocked by portcullis stones, into the King's Chamber.
The Big Void
In 2017, scientists from the ScanPyramids project discovered a large cavity above the Grand Gallery using muon radiography, which they called the "ScanPyramids Big Void". Its length is at least 30 metres (98 ft) and its cross-section is similar to that of the Grand Gallery.
The purpose of the cavity is unknown, and it is not accessible. Zahi Hawass speculates that it may have been a gap used in the construction of the Grand Gallery, but the research team state that the void is completely different to previously identified construction spaces.
The Antechamber
The last line of defense against intrusion was a small chamber specially designed to house portcullis blocking stones, called the Antechamber. It is cased almost entirely in granite, and is situated between the upper end of the Grand Gallery and the King's Chamber.
Three slots for portcullis stones line the east and west wall of the chamber. Each of them is topped with a semi-circular groove for a log, around which ropes could be spanned.
The granite portcullis stones were approximately 1 cubit (52.4 cm; 20.6 in) thick and were lowered into position by the aforementioned ropes which were tied through a series of four holes at the top of the blocks. A corresponding set of four vertical grooves are on the south wall of the chamber, recesses that make space for the ropes.
The Antechamber has a design flaw: the space above them can be accessed, thus all but the last block can be circumvented. This was exploited by looters who punched a hole through the ceiling of the tunnel behind, gaining access to the King's Chamber.
Later on, all three portcullis stones were broken and removed. Fragments of these blocks can be found in various locations in the pyramid.
The King's Chamber
The King's Chamber is the uppermost of the three main chambers of the pyramid. It is faced entirely with granite, and measures 20 cubits (10.5 m; 34.4 ft) east-west by 10 cubits (5.2 m; 17.2 ft) north-south.
Its flat ceiling is about 11 cubits and 5 digits (5.8 m;19.0 ft) above the floor, formed by nine slabs of stone weighing in total about 400 tons. All the roof beams show cracks due to the chamber having settled 2.5–5 cm (0.98–1.97 in).
The walls consist of five courses of blocks that are uninscribed, as was the norm for burial chambers of the 4th dynasty. The stones are precisely fitted together. The facing surfaces are dressed to varying degrees, with some displaying remains of bosses not entirely cut away.
The back sides of the blocks were only roughly hewn to shape, as was usual with Egyptian hard-stone facade blocks, presumably to save work.
The Sarcophagus
The only object in the King's Chamber is a sarcophagus made out of a single, hollowed-out granite block. When it was rediscovered in the early middle ages, it was found broken open and any contents had already been removed.
It is of the form common for early Egyptian sarcophagi; rectangular in shape with grooves to slide the now missing lid into place with three small holes for pegs to fixate it. The coffer was not perfectly smoothed, displaying various tool marks matching those of copper saws and tubular hand-drills.
The internal dimensions are roughly 198 cm (6.50 ft) by 68 cm (2.23 feet), the external 228 cm (7.48 ft) by 98 cm (3.22 ft), with a height of 105 cm (3.44 ft). The walls have a thickness of about 15 cm (0.49 ft). The sarcophagus is too large to fit around the corner between the Ascending and Descending Passages, which indicates that it must have been placed in the chamber before the roof was put in place.
Air Shafts
In the north and south walls of the King's Chamber are two narrow shafts, commonly known as "air shafts". They face each other, and are located approximately 0.91 m (3.0 ft) above the floor, with a width of 18 and 21 cm (7.1 and 8.3 in) and a height of 14 cm (5.5 in).
Both start out horizontally for the length of the granite blocks they go through before changing to an upwards direction. The southern shaft ascends at an angle of 45° with a slight curve westwards. One ceiling stone was found to be distinctly unfinished which Gantenbrink called a "Monday morning block".
The northern shaft changes angle several times, shifting the path to the west, perhaps to avoid the Big Void. The builders had trouble calculating the right angles, resulting in parts of the shaft being narrower. Nowadays they both lead to the exterior. If they originally penetrated the outer casing is unknown.
The purpose of these shafts is not clear: They were long believed by Egyptologists to be shafts for ventilation, but this idea has now been widely abandoned in favour of the shafts serving a ritualistic purpose associated with the ascension of the king's spirit to the heavens. Ironically, both shafts were fitted with ventilators in 1992 to reduce the humidity in the pyramid.
The idea that the shafts point towards stars has been largely dismissed as the northern shaft follows a dog-leg course through the masonry and the southern shaft has a bend of approximately 20 centimetres (7.9 in), indicating no intention to have them point to any celestial objects.
The Relieving Chambers
Above the roof of the King's Chamber are five compartments, named (from lowest upwards) "Davison's Chamber", "Wellington's Chamber", "Nelson's Chamber", "Lady Arbuthnot's Chamber", and "Campbell's Chamber".
They were presumably intended to safeguard the King's Chamber from the possibility of the roof collapsing under the weight of stone above, hence they are referred to as "Relieving Chambers".
The granite blocks that divide the chambers have flat bottom sides but roughly shaped top sides, giving all five chambers an irregular floor, but a flat ceiling, with the exception of the uppermost chamber which has a pointed limestone roof.
Nathaniel Davison is credited with the discovery of the lowest of these chambers in 1763, although a French merchant named Maynard informed him of its existence. It can be reached through an ancient passage that originates from the top of the south wall of the Grand Gallery.
The upper four chambers were discovered in 1837 by Howard Vyse after discovering a crack in the ceiling of the first chamber. This allowed the insertion of a long reed, which, with the employment of gunpowder and boring rods, forced a tunnel upwards through the masonry. As no access shafts existed for the upper four chambers they were completely inaccessible until this point.
Numerous graffiti of red ochre paint were found to cover the limestone walls of all four newly discovered chambers. Apart from leveling lines and indication marks for masons, multiple hieroglyphic inscriptions spell out the names of work-gangs.
Those names, which were also found in other Egyptian pyramids like that of Menkaure and Sahure, usually included the name of the pharaoh they were working for. The blocks must have received the inscriptions before the chambers became inaccessible during construction.
Their orientation, often side-ways or upside down, and their sometimes being partially covered by blocks, indicates that the stones were inscribed before being laid.
