The methods of construction of Egyptian pyramids remain uncertain. Archaeological data on these gigantic construction sites remains very fragmentary, while theories flourish and multiply, especially since the end of the 19th century, not to mention various pseudo-scientific speculations about pyramidology. They generally focus on the Great Pyramid, assuming that a method that can explain its construction can also be applied to all other pyramids in Egypt. In fact, there is no evidence that the same methods were applied to all pyramids of all types, sizes, and periods.
Issues and Constraints
The ancient Egyptians had to solve the numerous problems posed by the construction of the pyramids with the resources and technical knowledge available to them at the time.
Physical and Material Constraints
Different Types of Blocks
Several types of blocks must be distinguished:
- those that probably make up the bulk of the mass of the pyramids: a coarse layer of nummulitic limestone, a material found on-site, consisting of very uneven stones, but weighing several tons, with gaps of up to 10 cm. This layer of barely squared stones is visible from the entrance (Al-Mamoun’s hole) and in the shafts (niche of the queen’s chamber);
- an envelope of the same material (nummulitic limestone), constituting the very well-cut and perfectly aligned steps (but of variable height) visible today on all sides of the pyramid, with a mass of about 2 to 2.5 tons;
- blocks of the outer casing (missing on Khufu’s pyramid: only a few are still in place on the first course, but these smoothly dressed blocks from an underground quarry in Tura are clearly visible at the top of Khafre or on Dahshur-South/Rhomboïdale);
- blocks of the inner casing (all corridors of the pyramids, or the Grand Gallery of Khufu’s pyramid, for example) in fine limestone (but sometimes in granite, as in the king’s chamber), meticulously cut and fitted;
- megalithic blocks weighing tens of tons, such as the fifty-two monoliths of the king’s chamber of Khufu’s pyramid, each weighing from 25 to 40 tons, in syenite, a plutonic rock similar to granite but without quartz, which comes from distant quarries such as the quarry of Aswan, or the huge limestone chevrons of the entrance or royal chambers of the pyramids of Khufu and others.
Block Cutting
An example of the methods and tools used to cut megalithic blocks can be seen in the form of an unfinished obelisk in the quarries of Aswan, apparently cut by repetitive percussion.
Precision in Block Cutting
- William Matthew Flinders Petrie conducted a measurement campaign on the Great Pyramid and noted this high precision: “The average variation in block cutting compared to a straight line or perfect theoretical square is on the order of 0.010 for a length of 75 inches,” or 0.254 mm of error over a length of 1.90 m. To achieve this level of precision, even more precise tools and measurement methods are necessary: here we are talking about a tolerance of 0.00013 per 1. Petrie measured the dimensions of the pyramid itself and highlighted an error of only twenty centimeters for a perfect square of 230.30 m, an average error on the right angles of the base of 0° 3′ 6″, and an average error in orientation along the four cardinal points also of 0° 3′ 6″. The base of the pyramid was leveled with an error of only 21 mm.
- Christopher Dunn measured in 1992 the interior angle of the king’s chamber chest and found a constant value of 5/32 inches (or a radius of four millimeters) over the entire depth and on the four corners. Dunn also measured the flatness of a twenty-seven-ton granite block, with a precision of 0.0002 inches (or 0.005 mm).
Nevertheless, the vast majority of limestone blocks making up the pyramid were roughly cut, and only a minority of visible blocks were cut with precision.
Block Transport
The transport methods must have been very diverse, depending on the type of blocks to be transported. River transport must be considered for some, and land transport for others; the large granite blocks extracted from the quarries of Upper Egypt must have successively experienced both modes of transport.
Lifting and Positioning of Blocks
The highest of the pyramids, that of Khufu, formerly reaching 146 meters, required the Egyptians to apply techniques allowing them to raise and position blocks weighing several tons to these heights. In addition, the heaviest blocks (about 73 tons) had to be raised fifty meters (to the king’s chamber where they form the “roof”).
Number of Blocks Required
Although the number of 2,000,000 has often been mentioned, it does not correspond to the reality of the pyramid works, which are not made up solely of properly cut stones.
According to the measurements of Charles Piazzi Smyth, there are two hundred layers of blocks on the pyramid, so according to this relationship, 2.6867 million blocks are obtained.
Material Constraints
While it is possible to cut and polish materials with tools of lower hardness, the human work required is multiplied, as is tool wear, and therefore the amount of material needed to outfit the workers.
Hard rock percussion tools (granite, diorite) are a probable hypothesis for cutting the soft limestone that constitutes the vast majority of the pyramid blocks.
- The absence of the wheel (stone blocks were transported on sledges, as shown in some contemporary representations).
- A workforce of about 100,000 men (according to Herodotus), or from 10,000 to 15,000 at the peak of the work according to modern estimates.
The number of 100,000 workers is probably a figure proposed by Herodotus to impress the reader, as the population in Egypt did not exceed one million inhabitants at that time.
Temporal Constraint
- Herodotus reports that the Great Pyramid of Giza was built in twenty years, an estimate also mentioned by the ancient historian Manetho. The starting year and the duration of the pyramid’s construction are hypotheses generally validated by Egyptologists because they correspond to 23 to 25 years, depending on the sources, of the reign of Pharaoh Khufu. Unfortunately, these estimates are not attested by any contemporary writing but are logically deduced from the accepted assumption that the pyramid was intended as the tomb of this pharaoh, an assumption itself not attested by writings.
- The Greek historian also reports that Egyptian workers only worked there for three months each year (his wording, ambiguous, suggests that they were renewed every three months, but this period probably corresponds to the flood season during which thousands of peasants were conscripted for corvée duty, a number much higher than that of workers working permanently). This would mean sixty months of work or only five years of effective working time. This would mean placing approximately 1,369 blocks per day. If these five years were worked twenty-four hours a day, about fifty-seven blocks would need to be placed per hour, cut, transported, assembled, and adjusted to the millimeter for some of them. But this interpretation confuses frequency and “assembly time”: the fact that fifty-seven blocks are placed on average per hour does not mean that the manufacturing line produces and places fifty-seven blocks per hour, notably because the different stages of production are simultaneous for different blocks.
However, if theories of external access ramps are considered (see further in this article), the calculation should also include the blocks and materials necessary for the construction of the ramps themselves.
It is also necessary to take into account the other pyramids built during the 25 years of Pharaoh Khufu’s reign (Pyramid G1D, Pyramid G1A, Pyramid G1B, and Pyramid G1C), which, although of much smaller dimensions, also required resources in terms of manpower, materials, tools, and supplies.
Contributions to Egyptology
Origin and Exploitation of Raw Materials
The pyramids of the Old Kingdom are entirely made of stone blocks, more or less well squared depending on their destination in the monument.
Internal Mass of the Pyramids
The stones of the internal mass (envelope and core) of the pyramids in this group come from local quarries whose traces remain on the Giza plateau, below, and all around the Sphinx. The nummulitic limestone of these quarries comes in horizontal beds of very variable height and hardness, separated by layers of “tafla” clay, which form a sort of cleavage, considerably facilitating the extraction of stone blocks.
Georges Goyon hypothesized that stones detached from the quarry in horizontal layers between the clay beds were simply cut into large blocks and reassembled on the pyramid in the same order, with joints therefore perfectly formed without having to touch them.
This hypothesis provides an explanation for the absence of gaps observed between the vertical joints of the pyramid’s casing, and the presence of oblique or irregular joints, which are very difficult to achieve otherwise. It would also explain the irregularities in the height of the courses, determined by the thickness of the stone beds in operation.
Fine Limestone Covering
The pyramids were covered with blocks of fine, hard limestone, perfectly cut and polished, from the quarries of Tura and El-Maasara.
Granite Covering (Khafre, Mykerinos)
The pink granite blocks adorning the base of the Khafre and Mykerinos pyramids, also used for the masonry of the funeral apartments, came from the distant quarries of Syene (Aswan).
Materials for the Middle Kingdom Pyramids
On the other hand, the bulk of the masonry of a Middle Kingdom pyramid is composed only of mud bricks; only the covering and the reinforcement walls of the structure are made of limestone.
Tools
The tools available to the Egyptians during the Old Kingdom were mainly inherited from the Neolithic period. The ancients acquired, with lithic tools, great experience in cutting hard stones, as evidenced by the sculpted vases during the Thinite period.
This equipment consisted of mallets and hammers made of diorite or dolerite, blades and knives made of flint, percussion tools, and drills. Half-spheres of limestone allowed the crushing of debris into powder intended for mortar production.
The metal used during the Old Kingdom was mainly copper, used in the form of chisels or toothless saws, combined with sand (composed of quartz grains) used as an abrasive. This latter instrument allowed for cutting the hardest stones, as experimentally demonstrated by Denys A. Stocks.
Some today consider that the Egyptians did not use it pure; the ores of the time contained percentages of arsenic and bismuth, constituting an alloy harder than pure copper.
Wood was also present on the construction sites, used for the manufacture of sledges, levers, logs, and for stone extraction.
Rocking levers and swinging elevators
Rocking levers have been used by all civilizations.
There is a wooden instrument at the Cairo Museum called a swinging elevator, a sort of sled with curved skates whose block fixed on the swinging cradle rises thanks to increasingly high wedges placed under each end. This apparatus, which was used in construction, allows lifting stones weighing several tons. Feasibility and speed tests have made the use of this tool possible. Despite its “relative slowness,” it is favored by Georges Legrain and Flinders Petrie, while for other Egyptologists, this technique was not used until the New Kingdom; no trace is found concerning its use during the Middle or Old Kingdom.
Transport of stone blocks
Secure documents only date from the New Kingdom, or even the Middle Kingdom. The few scattered archaeological traces (remains of ramps and bas-reliefs) from the Old Kingdom do not definitively resolve the debate imposed by the lack of epigraphic sources. However, considering the consistency of the ancient Egyptians in construction matters and the slow evolution of techniques in antiquity, it is possible to assume methods used to transport stones from, for the furthest among them, the region of Aswan.
Haulage
Once the stone was extracted from the quarry face, the workers had to place it on a wooden haulage sledge (Egyptian acacia, oak, or Lebanese cedar), which they then slid on the ground using hemp ropes, regardless of the distance from the pyramid construction site.
The oldest known sled dates from the Twelfth Dynasty (discovered in the royal necropolis of Dahshur; it is exhibited at the Egyptian Museum in Cairo) and was used not to move dressed stones but to transport large funerary boats from the funerary complex of Sesostris III.
A relief dating from the Middle Kingdom depicting the transport of the colossus of Djehutihotep fixed on a sled perfectly illustrates this principle. There is no doubt that heavy loads (boats or stone blocks) generally had to use this means of transport for long distances. Tracks had to be laid to facilitate the sliding of the sleds, as suggested by the slide at Mirgissa. These sleds were pulled by men, the number of which varied depending on the load to be pulled and the slope. Thus, the colossus of Djehutihotep, weighing about sixty tons, is pulled by 172 men distributed over four rows.
The transport of huge monoliths, such as that of the upper temple of the funerary complex of Khafre, weighing over 400 tons for a volume of 170 cubic meters, is more problematic. Was the movement of such masses, whose weight equals that of the obelisks implemented under the New Kingdom, done on a sledge or on beams? Any proposed solution can only be conjectural.
The stones were all hauled by men, as shown in another rare representation from the Fifth Dynasty: two rows of haulers are depicted in a relief from the causeway of Sahure. The load to be pulled has disappeared from the scene, but the legend describes the transport of the pyramidion that was to crown the top of the pyramid. Moreover, a painting from the New Kingdom, executed in a quarry at Ma’asara, shows a dressed block pulled by three oxen. This undoubtedly exceptional fact does not exclude the possibility that the Egyptians may have used animal traction from the beginning of their history.
River Transport
To transport stones from distant quarries (Assuan is located nearly a thousand kilometers from the Memphite region of the pyramids), river transport on the Nile was necessary, as confirmed by Merer’s journal (papyri written by an official, Inspector Merer).
River transport, perfectly mastered, was essential to the ancient Egyptians. They had at their disposal boats specially adapted to heavy loads (barges carrying monolithic columns and probably granite blocks either at the bottom of the hold or suspended in the water between two boats), as evidenced by the bas-relief on the causeway of Unas. The activity reached its peak during the flood period, but, to overcome the difficulties associated with the periods of low water, a navigable waterway was dug parallel and west of the Nile, allowing convoys to unload their heavy loads at ports located at the temples’ lower levels of various construction sites.
Stone Elevation
The problem of elevating stones onto the pyramid’s courses is the one that attracts the most public attention. Egyptologists have often opted for solutions based on ramps, the shapes and dimensions of which remain to be defined, while specialists in other disciplines strive to provide their own explanations.
Nevertheless, some remnants of ramps remain, notably at the pyramid of Meidum, the pyramid of Sekhemkhet, and that of Khafre, as well as the pyramid of Sinki, and especially that of Sesostris I, at Licht. All of these are frontal ramps, perpendicular to the faces. If they were indeed used, they could not have been sufficient to complete the building, especially in the phase of laying the perfectly fitted facing stones, as at the pyramid of Khufu.
Herodotus reports the use of wooden machines with no equivalent known to Egyptology. Perhaps these are to be compared to the maneuvering devices used in the construction of the Nubian pyramids and inspired by shadoofs.
Contemporary Theories
Since antiquity, two interpretative models have opposed each other: the “rampist” theories following Diodorus Siculus, which propose to hoist the monoliths and all the necessary materials by sliding them on a ramp or earthen embankment; and the “machinist” theories, like those of Herodotus, which propose the use of lever systems. A third family of “mixed” theories proposes to build a ramp up to the level of the king’s chamber and then to use a lever.
Ramps
Frontal Ramp in Mud Brick
This theory was first developed by the German Egyptologist Ludwig Borchardt, who interpreted the presence of remnants of ramps around the pyramid of Meidum. It consists of a single ramp, perpendicular to one face of the pyramid, with a constant slope regardless of the elevation. This implies that its length increases proportionally with the number of courses in the pyramid. The blocks, placed on sledges, were then hauled up the ramp by the strength of the workers’ arms. Oil poured on the ground between the haulers and the runners helped slide the sledges.
The major drawback of this theory is that the ramp takes on considerable dimensions and ultimately represents a workload as colossal as the pyramid itself. Therefore, this principle was modified, notably by Jean-Philippe Lauer, who proposed a single linear ramp in mud brick, perpendicular to the face facing the Nile, of variable length up to a low height, then of constant length with variable slope.
The ramp, according to these two theories, poses significant problems in mechanics and civil engineering:
- either the ramp has a low slope and an extremely long length. The volume of material represented by the ramp, which would then need to be cleared, is enormous, of the same order of magnitude as the volume of the pyramid itself;
- or its slope rises as the pyramid is built, giving it a very steep slope. The slope for hoisting the blocks becomes enormous, far beyond what is acceptable for a passable road (namely 7%), and even more so for hoisting blocks.
- This theory therefore has gaps. It is difficult to reconcile with soil conditions, available space, which are known to civil engineers, and the possibilities of human traction, which are now better known thanks to experimental archaeology.
Helical Ramp in Mud Brick
This theory is endorsed by many commentators. It relies on the construction of the pyramid with ramps made of mud bricks parallel to the faces, allowing the stones to be pulled from one level to another. Completely enveloping the construction, this ramp would have allowed the elaboration of each course, including the facing stones, offering a plausible explanation for the finishing of the facing stones from the top of the pyramid. Indeed, once the pyramidion was placed, it only remained to dismantle the ramp from the top, revealing the facing blocks that only needed to be smoothed. Some object to this theory on the grounds that the construction of these ramps, which are 1.6 km long, would have required colossal energy, that the slopes chosen would be incompatible with the geotechnical behavior of the materials used, that the ramps would make it difficult to align the edges of the pyramid, which became invisible, and that it is inconsistent with Herodotus’s testimony.
Although this theory is favored by many Egyptologists, it faces a stumbling block: how can 300 haulers continue to pull loads around bends where it would be impossible for them to deploy? Georges Goyon presents milestones acting as corner returns for traction ropes, a solution that is only a drafting hypothesis, not validated in terms of mechanical resistance.
Side Ramps
This theory consists of attaching spiral side ramps to the faces of the steps of the internal massif of the pyramid. It was first put forward by the German Egyptologist Uvo Hölscher. The major drawback is the steep slope imposed on the ramps, which can only extend over the length of the faces. This system can therefore only allow the elevation of relatively light stones. Furthermore, it makes the final face impossible. This theory seems better suited to the construction of stepped pyramids, the mass of the stones to be assembled rarely exceeding 350 kg, which would also make it possible to use a steep frontal ramp.
Side Ramp with Extension
The German Egyptologist Rainer Stadelmann designed a side ramp that extends widely in front of the pyramid, so as to soften the slope.
Embedded Ramp
His colleague Dieter Arnold presented a variant of the previous ramp, no longer lateral, but embedded in the pyramid and also extending widely outside.
Spiral Ramp
In 2024, Rudolf Volz presented his theory of multi-spiral ramps. The ramps are placed on the internal stepped pyramid. In total, seven ramps start from the lowest level. The wide main path starts from the south side of the pyramid and leads to the top, allowing the pyramidion to be placed at the summit. Two narrow ramps start on the three other sides and end at different heights.
Frontal Ramp and Internal Ramp (Jean-Pierre Houdin’s theory)
In 1999, the French architect Jean-Pierre Houdin published, with his father Henri, an engineer, a first article concerning the construction of the Great Pyramid of Khufu using an internal ramp, in the ID Review of the National Council of Engineers and Scientists of France.
With the Egyptologist Bob Brier, Jean-Pierre Houdin then developed his theory of an external frontal ramp up to a height of 43 meters. The Grand Gallery would have served as a guide for a carriage carrying a counterweight to facilitate the ascent on the external ramp of the heaviest blocks. The construction of the pyramid would have continued with an internal spiral ramp, and the limestone facing blocks, already surfaced, would have been placed first.
The frontal ramp would have been double; one ramp would have been used to raise the stone blocks while the other ramp was raised, thus allowing work to continue.
The architect highlights the flaws of other theories to support his own. Thus, a frontal ramp going up to the top of the pyramid would require a slope that is too steep or a volume that is too large. The spiral ramp advocated by Georges Goyon would have lacked stability and would have offered haulers too little freedom. That is why he puts forward the theory based on the design of an internal ramp that would have allowed the stone blocks to be raised for the continuation of the work: this spiral-shaped ramp would have run a few meters from the faces of the pyramid, in twenty-one sections and over 1.6 km. At each meeting of one of the edges, an open space would have allowed the stone blocks to be turned.
Jean-Pierre Houdin relies on several archaeological clues to support his hypothesis. One of them is the presence in the obelisk masonry of a solar temple (that of Niuserre at Abusir), which he describes as an internal ramp. The site, dating from the Fifth Dynasty and meticulously studied by Ludwig Borchardt, does indeed present an internal spiral structure, a staircase leading to the terrace of the first trunk of the obelisk. The other main argument is the control of the edges of the pyramid, which only the construction by internal ramp would have allowed to master. The author argues that the faces of the pyramids were to remain clear and possess, from the first stone beds, their limestone facing.
Micro-gravity measurements, conducted by EDF in 1986 during a study by French architect Gilles Dormion, revealed density differences in the spiral-shaped infrastructure. Dormion interpreted these measurements as evidence of the presence of steps within the body of the pyramid. This phenomenon has already been observed in other pyramids in a more advanced state of ruin. The Pyramid of Menkaure, torn open on its north side, displays such steps. The Pyramid of Meidum, a collapsed, smooth-faced pyramid, now only shows its internal stepped core. The Fifth Dynasty pyramids also had this type of infrastructure. This particularity demonstrates that the Egyptians, while evolving their monuments, incorporated into their structures architectural and symbolic elements that developed over a long period of time. Jean-Pierre Houdin, on the other hand, sees it as the presence of an internal spiral structure.
The design of this structure, equipped with a corbelled vault along its entire length, similar to the Grand Gallery but 1.6 km long, would have required very delicate implementation.
Such an internal ramp has never been discovered either in the Pyramid of Khufu or in the Pyramid of Khafre (the pyramid presents the same technical challenge as Khufu’s). But only further study of the monument would validate or invalidate this theory.
Frontal Ramp and Internal Ramp
Other individuals have also developed a theory using an internal ramp:
- Italian Elio Diomedi.
- Frenchman Jean-Rousseau in his book “Construire la grande pyramide,” Editions L’Harmattan, 2001, refers to it in a paragraph on page 161.
Ramps and Machinery
Zigzag Ramps, Goats, and Capstans
Jean-Pierre Adam favors a system of four zigzag ramps, one on each face. But he does not rule out the complementary use of goats, already proposed by Auguste Choisy, or capstans powered by human strength. According to Jean-Pierre Adam, the Egyptians knew about the wheel.
Jean Kerisel, a polytechnician and civil engineer, proposes solutions of a similar nature. Also, Jean Kuzniar in his book “La pyramide de Khéops, Une solution de construction inédite,” editions du Rocher.
The ramp principle is an insufficient theory in terms of hypotheses about implementation methods and is only a partial element of understanding the logistics and spatial organization of the construction site. This theory needs to be improved to address issues with its foundation on the pyramid and means of hauling blocks. These theories and the hypotheses of their implementation methods need to be verified in detail by basic civil engineering calculations, such as the load-bearing capacity of the track, material volume, block transport speed, labor space required, friction coefficients, and surveying methods.
These verification elements are rarely presented by Egyptologists in published works, and their presentations remain mechanically questionable, leading to simple hypothesis formulations.
Machinery
Goats
Auguste Choisy, a polytechnician and civil engineer, hypothesizes about construction in stages and in layers like an onion.
German Egyptologist Uvo Hölscher first advocated for the idea of zigzag ramps (recently taken up again by Jean-Pierre Adam), then turned to handling methods like lifting tongs.
Hermann Strub-Roessler picks up the idea of goats but of a much more elaborate design than A. Choisy’s, with multiple capstans and maneuvering ropes forming a rectangular gantry.
The absence of pulleys and winches until the 12th dynasty excluded the use of these goats originally.
Elevators
Louis Croon, a German engineer, adopts the principle of the shaduf, i.e., a large lever operated on an axis and rotating for the occasion. He also studies a type of frontal ramp not far from that of Jean-Philippe Lauer but of constant width.
In 1993, L. Albertelli proposed a lever system capable of pulling a 30-ton monolith along the pyramid’s wall, thanks to a basket weighted with workers.
In 2007, Philippe Tixier proposed a chain of balances, each operated by a team of 35 men who move on the balance. A block weighing two and a half tons would thus be hoisted from one course in less than ten seconds. The next block would be hoisted about twenty seconds later. Such a chain can lift up to two thousand blocks each day to the construction level.
Theory of the Construction System of the Pyramids
The construction system of the pyramids proposed by Pierre Crozat, an architect and engineer from EPFL, is based on an analysis of the history of building techniques, the geology of the site, and a literal interpretation of the writings of Herodotus, which report the words of Egyptian priests of his time regarding the construction of the pyramids. In this system, the pyramidal shape of the building comes from the way the blocks are put together, which Crozat calls a “constructive algorithm” and involves corbelling them one after the other with a lever on a tripod. This constructive algorithm only generates pyramids. The materials come from quarries, the faces of which and the leftover pieces can still be seen today. According to its author, this theory allows the major smooth Egyptian pyramids to be situated within a “technical continuum,” originating in the early agricultural stone constructions of the Neolithic period, based on a universally widespread construction method called “accretion – buildup,” which generates, organizes, and formalizes all tumular structures, including stepped pyramids, over time and space. It was the subject of a doctoral thesis at ENSMN.
Alternative Theories
Transport and Lifting by Canals and Locks
According to Jean-Pierre Adam, Pliny the Elder already advocated transporting obelisks and other heavy monoliths suspended between two boats and submerged so that they lost more than a third of their weight due to Archimedes’ principle. Towing then becomes possible, even easy, similar to that of heavy barges on our canals.
Manuel Minguez, a civil engineering technician, presented in 1985 a hypothesis for the application of hydraulic means to transport megaliths, to the construction of pyramids, and to the erection of obelisks: he conducted experiments in full-scale towing and developed the idea of monoliths suspended and submerged between two barges; then he described a system of locks for the construction of pyramids. The obelisks, on the other hand, brought down the river from the quarries of Aswan, did not require towing but rather effective braking. They were set up and erected, according to Manuel Minguez, by straightening in an artificial basin, in a controlled manner and reversibly at any time.
Hypothesis of Molded Stones
According to this hypothesis, some of the stone blocks of the Egyptian pyramids were not carved but molded, like concrete. Since 1978, Professor Joseph Davidovits, a chemical engineer, has developed the theory that the Egyptian pyramids are not made of carved stone blocks but of re-agglomerated stone: natural limestone disaggregated, mixed with a binder, then molded.
In 2006, the concurring conclusions of a team of researchers at Drexel University, led by Michel Barsoum, added credibility to this thesis.
In 2012, a scientific study published in the journal Europhysics News highlighted the artificial nature of some of the stones of the Egyptian pyramids.
Since 2001, Joël Bertho, a structural architect, has proposed another theory on the pyramid in reconstituted stone.
Stair Construction
In the book “Pyramides ou le principe de l’escalier” (Pyramids or the principle of the staircase), 2012, ed. L’Harmattan, Eric Guerrier develops a thesis suggesting that the pyramids were built, without ramps, by successive steps with the help of simple principles of rudimentary machines.
Testimony of Ancient Authors
Herodotus’ Machines
When Herodotus visited Egypt around 450 BC, the country had been under Persian rule for just under a century (the XVII dynasty). Not speaking the Egyptian language, Herodotus had to rely on translators or be content with the accounts of Greek colonists living in the country. It is difficult to know what knowledge the Egyptians of the time could have had about construction methods for monuments that were already over 2,000 years old, and one can only question the veracity of the statements reported by Herodotus; it seems unlikely that they are entirely accurate.
Size and Transport of Stones
“Some had to drag the stone blocks from the quarries of the Arabian Range to the Nile; others had the task of receiving these stones, carried by boats to the other bank, and dragging them to the mountain called the Libyan Range. A hundred thousand men worked at once, relieved every three months.”
Assembly of the Pyramid
“Here’s how this pyramid was built: by a system of successive steps called krossai (corbels), sometimes bomides (platforms). It was first built in this form, then the additional stones were hoisted using machines made of short pieces of wood: the stone was lifted from the ground to the first platform; there, it was placed in another machine installed on the first step, and pulled up to the second step, where a third machine took it.”
In fact, Herodotus gives no indication of the method of construction of the pyramid itself. He just says it was built by the “system of successive steps,” and only for the facing stones (“additional stones”) does he report the technique of lifting machines using wooden levers.
Leonardo da Vinci is said to have drawn a machine based on Herodotus’s description. Subsequent representations are based on Leonardo da Vinci’s sketches in the Codex Madrid. Visual representations cannot claim to accurately depict Herodotus’s machine.
Soluble terraces of Diodorus Siculus
The Greek historian Diodorus Siculus (1st century BCE) does not at all propose “the hypothesis of ramps and sledges,” as is often repeated: he only reports that “the stones were, it is said, arranged using terraces […] of salt and nitre (the ancient name for Egyptian natron), which would have been dissolved by the waters of the Nile.” No ramps, no sledges in Diodorus: at most “terraces” (which is very different), to which he says he does not believe.
“Lintels” of Strabo
The Greek geographer Strabo traveled to Egypt in 25 BC or 24 BC. In his Geography (XVII, 1,33-34), he only mentions, serving as a door in the outer facing of the Great Pyramid, a “stone that can be removed (λίθον ἐξαιρέσιμον) and which, once removed, reveals the entrance to a winding gallery or syringe, leading to the tomb”; he also mentions the granite cladding, up to mid-height, of the pyramid of Mykerinos and finally the presence of “lintels” (nummulites) throughout the plateau. He says nothing about the construction methods of the pyramids.