How did the ancient Egyptians build the Great Pyramid at Giza?

No one throughout the ages has enjoyed so sublime a tomb as that of King Khufu, builder of the magnificent Great Pyramid of Giza.

The son and successor of King Snefru and Queen Hetepheres, Khufu reigned for 23 years, a period marked by economic stability and artistic progress. The able and energetic King erected several monuments in Egypt and in later years his name, found engraved on scarabs, apparently assumed a potent, protective charm.

Little else is known about this second king of the IVth Dynasty (2613-2498 B.C.); indeed, there is no evidence to support the claims of classical authors that he was a tyrant, abhorred by all compelled to labor on his behalf. It is more likely, according to Ahmed Fakhry, author of The Pyramids, that these subjects were more than willing to work for the eternal glory of their ruler, who in their eyes was a god.

The Great Pyramid culminated in both size and quality a long tradition of pyramid building. The awesome edifice, perhaps chief of the Seven Wonders of the World, gives pause even to modern-day architects and engineers who have 5,000 years of experience on the ancient Egyptians and the aid of advanced technology.

Without wheels, pulleys, compasses, or tools of any metal other than copper, the Egyptians raised a pyramid almost perfectly aligned with the cardinal points, covering an area of over 13 acres, and piercing the sky at a height of 481.4 feet. An estimated 2.3 million blocks of stone make up the Great Pyramid. Weighing an average of 2 1/2 tons each, some as much as 15 tons, the limestone and granite monoliths were cut, hauled, and positioned with enormous precision. St. Paul’s Cathedral and the Houses of Parliament could stand within the perimeter of the base, with ample room to spare. And if all the stones in the pyramid were sawed into blocks one foot square and laid end to end, the line would stretch two thirds of the way around the earth at the equator.

Extant Egyptian texts say all too little about the construction of the pyramids, and authorities continue to puzzle and disagree over the methods employed. What is known has been surmised from the pyramids themselves and some knowledge of the type of implements available to this extraordinary society.

The first task for King Khufu and his engineers was the selection of an appropriate site. Certain strictures always applied. The tomb had to lie on the western bank of the Nile, for the realm of the dead lay in the west, where the sun went down. It required a strong supportive base of solid rock and sufficient room for the surrounding mortuary temple, causeway, valley temple, and canal connecting with the Nile. East of the Great Pyramid stand three small ones, erected for the King’s wives or possibly for a wife and two daughters. Herodotus recounts a spurious story that the central pyramid was built by one of Khufu’s daughters, whom the King prostituted in order to gain funds for his own tomb. The young lady allegedly asked each lover to contribute a stone and so looked after her own immortality.

King Khufu chose a plateau, rising 200 feet above the river, near the ancient capital of Memphis; it is part of the Memphis cemetery extending from Abou-Rawash in the north to Meidum in the south. His workers removed the thick surface layer of sand and gravel, so that the pyramid might stand on the firm rock substratum. Next they leveled and smoothed the rock, a technique learned gradually over the years from preparing lands for irrigation. The workers built four banks of Nile mud around the area to be leveled and filled the enclosure with water. They then cut a maze of trenches, each lying at precisely the same depth beneath the water’s surface. Later, after the water was run off, the areas between the trenches could be leveled to them, The system produced superb results: the perimeter of the pyramid’s base deviates from true level by just over half an inch. The area within did not have to be absolutely level with this perimeter, and in fact a mound of rock was left in the center and used later.

The principal architect, Hemlwnw, Khufu’s cousin, then had to align the four sides of the pyramid with the four cardinal points. Here King Khufu himself might have been seen ceremoniously drawing the first line and assuming the power of this wisdom before his people, but it was undoubtedly the architects and astronomers who did the tricky calculations, all without the aid of the magnetic compass. Their errors amount only to fractions of a single degree. (The north side is 2’28” south of west, the south side 1’57” south of west, the east side 5’30” west of north, and the west side 2’30” west of north.) Could the architects have observed the sunrise and sunset on the two annual equinoctial days, or taken an accurate reading of the north by observing the Pole Star? I.E. S. Edwards in The Pyramids of Egypt maintains that in both cases the resultant error would have been far greater than that found at the Great Pyramid.

For a description of the foundation ceremonies and implements used, historians are forced to look to texts written many years after the pyramids were built, and speculate that the methods were fundamentally the same. Two devices were employed: the merkhet and the bay, both mentioned first in the texts of the XVIIIth Dynasty.

The merkhet, which means instrument of knowing, consisted of a narrow horizontal bar with a small block rising above the level of the bar at one end, from which a plumb line was suspended. This was used with a bay, or palm rib with a V-shaped slot in the wider end. A likely approach was to observe a star in the northern heavens and bisect the angle formed by its rising position, the point of observation, and its setting position.

For an accurate reading, the Egyptians would need a true horizon; since their natural one was distorted by the line of the land, the architects had to build on the leveled plateau a circular wall whose upper rim would serve as a horizon. One person, positioned at the center of the circle, would sight through a perpendicular rod or slot of the bay. When he saw the rising star he would instruct another person to mark with the merkhet the exact spot on the wall, i.e., the direct line between the observer and the star. Some hours later another observation would be made, this time toward the west, and the place indicated by another merkhet. The two plumb lines, suspended from the wall, would indicate two points perpendicularly below, at the base of the wall. By bisecting the angle formed by these two points and the observer, the Egyptians could find true north. The reading might be checked by observing other stars in a similar way. Once one axis was established, the other could easily be found by marking off a set square.

The four sides of the Great Pyramid were originally just over 755 feet each at the base (now slightly shorter because of lost casing stones), with the greatest difference between them only 7.9 inches. This error probably resulted from the cords used in measuring the base, which were of palm fiber or flax fiber and naturally stretched when used. Because of the mound in the middle, the Egyptians were unable to measure the diagonals to double-check their work; still, they were remarkably accurate.

While all this was going on, gangs of workers were already toiling away to obtain the staggering volumes of stone that the King desired. From inscriptions painted on some of the rocks we know that each of these gangs had a name, e.g., “The Craftsmen-gang. How powerful is The White Crown of Khnum Khufu!” Marking the stones may also have provided a way for overseers to check the workers’ productivity. The stones are predominantly limestone, taken from the plateau itself and nearby quarries with nothing but copper chisels and saws, flint tools, quartz and diorite pounders, and wooden crowbars. The gangs cut away three sides of each stone with a chisel struck by a wooden mallet. They then inserted wedges into holes cut at the bottom and freed the rock from its base. Sometimes these wedges were of wood, which expanded when wet and thus caused the rock to split. This process was made yet more difficult when tunneling was required, as at Tura on the eastern coast of the Nile, where finer-grained limestone was quarried for the outer casing. Here confined space severely restricted mobility and the number of workers.

Historians continue to debate how the Egyptians of the Old Kingdom were able to quarry granite, a much harder stone than limestone. One authority insists that they could not do it at all and simply used what was found on the ground. Some maintain that wedge slots could have been made by rubbing an abrasive powder with a stone or metal tool; others say the workers pounded around the desired rock with balls of hard dolerite, a stone widely distributed over the eastern desert near the Red Sea.

The Egyptians then had to transport their stones, something they proved to be remarkably good at over the years, later moving the 1,000-ton colossus of Ramses II to Rameseum at West Thebes. Megaliths from Aswan and Tura were floated on barges during flood season. Overland transport was effected without wheels, in much the same way as at Stonehenge.

Workers levered the stones onto sledges or dragged them on via short stone ramps. They then raised both stone and sledge, bound securely together with ropes, enough to slide wooden rollers underneath. Straining on ropes attached to the sledge, the men dragged the sledge along a way lined with logs, while others poured water or milk over the timber to prevent fires resulting from the friction. Offerings may well have been placed on the stones and incense burned as the gangs sweated over their slow and painful work. Herodotus reports that 100,000 men were employed for periods of three months just for the task of transporting the stones, but these figures have not been confirmed. He claims, furthermore, that the causeway required 10 and the pyramid itself 20 years to build, somehow overlooking the fact that Khufu reigned for only 23.

More certain is the number of full-time workers engaged in building the pyramid. Sir Flinders Petrie, who did the first exhaustive survey of the pyramid in 1880-1882, discovered barracks lying west of the Pyramid of Chephren and presumed that they once housed these skilled workers and could have accommodated about 4,000. In 1978 and 1980 Zahi Hawass, chief inspector of the Giza pyramids, excavated a site northeast of the Great Sphinx and found under the modern village of Nazelet-el-Saman a village called Busiris dating from the Greek and Roman period. He also found Old Kingdom deposits suggesting that at this site there was once a workers’ village from the time of Khufu and even a palace for the King. Thus Khufu not only oversaw construction of his tomb but ensured ample food, clothes, and shelter for thousands in his employ. His organizational abilities were yet another awe-inspiring factor in the building of the Great Pyramid.

Once the stones had been dragged to the plateau, a skilled group of workers smoothed, shaped, and assembled them. After the first tier, their work was considerably harder. How the stones were raised without pulleys has puzzled historians, architects, and engineers for centuries, and the definitive word has not yet been written. Most now agree, however, that the only feasible method was the use of ramps, and tangible evidence appears at the unfinished pyramid of King Sekhem-khet at Saqqara, where the rubble of such ramps was found. In Ancient Egyptian Masonry, architect Somers Clarke and engineer R. Englebach outline a system employing both long, wide supply ramps with a fairly easy gradient and shorter, steeper ramps for laborers to transport lighter materials. Edwards suggests that a single supply ramp was constructed over an entire side of the pyramid and raised successively as the monument went up. Like that of the pyramid itself, the ramp’s angle would have been 52°. On the other three sides, meanwhile, foothold embankments would have been formed, sufficiently wide for men to navigate with building materials.

Other Egyptologists argue that a single long ramp was unfeasible because of the difficulty of raising and extending it at each level. In 1950 Dows Dunham, curator of Egyptian and Ancient Near Eastern Art at the Museum of Fine Arts in Boston, oversaw construction of a model of the third pyramid at Giza on a scale of 1:120. This model incorporated four ramps, one starting at each corner. Dunham maintained that the three were used for delivery of stones and the fourth reserved for men descending with empty sledges. Each ramp would have been about ten feet wide, sufficient for the sledges, a double row of men to haul them, and wet timber laid like railway ties to reduce the friction.

Imagine the pyramid in the midst of construction at about half its present height, the top a fiat, square surface. In the broiling sun, thousands of workers mill around its base. On the ramps, they are hauling the core stones from local quarries; these are left rough on all sides except the bottom. Placed side by side, the gaps caused by their uneven surfaces are left open, but careful measurements are made to keep the sides of the square of equal length. Sometimes internal casing of Tura limestone is added to make up the difference.

Finally, only a narrow margin remains at the outer edges of the square platform. Skillful workers now position the limestone “packing blocks” with close-fitting joints. The task becomes still more delicate, for it is time to add the outer casing of Tura limestone. Expert masons shape the precise angles of these stones on the ground, perhaps fitting them to the packing blocks before these are hauled away. The masons leave bosses on the outer face of every casing block so that levers may be used. They spread a thin layer of mortar on the bottom and inside surfaces, which facilitates sliding the stone into position. Once the stone is hauled up the ramp and laid on the casing block below it, men position it precisely by pulling on ropes attached to its outer corner, then by levering it from the front against the packing block.

Petrie took a close look at the few casing blocks that remain at the Great Pyramid, and his report of the accuracy of measurement is absolutely incredible: “The mean thickness of the joints of the north-eastern casing-stones is 0.02 inches, and therefore the mean variation of the cutting of the stone from the straight line and from a true square is but 0.01 on a length of 75 inches up the face, an amount of accuracy equal to the most modern opticians’ straight-edges of such a length. Though the stones were brought as close as 1/50 inch, or, in fact, in contact, the mean opening of the joint was but 1/100 inch.”

Once the casing stones are on all four sides, a survey is made. Ramp and embankments are meanwhile raised and the entire process repeated. After many, many years of labor, the workers one day haul up on a sledge the pinnacle of the pyramid—the capstone. They support it on levers and place it on battens. The square surface at the top has been covered with mortar and a small depression cut to hold a protruding disc on the bottom of the capstone, a mortise and tenon system to keep the stone in place. Finally, they remove the battens and secure the lofty pinnacle. Even now the work is far from over. They must dress the stone as they descend, and gradually dismantle the ramp. Then they must clear the grounds and prepare to build the mortuary temple, the causeway corridor, and the valley temple.

As a footnote to this Herculean effort, it must be recalled that the Great Pyramid contains a maze of interior passages, the Queen’s Chamber, the King’s Chamber, five “relieving chambers” (designed to take much of the weight of the upper pyramid from the roof of the burial chamber), and the majestic Grand Gallery, a corbel-vaulted passage 153 feet long.

The details of construction are too many to describe here, and much remains unknown. It is probable, however, that this work was done independently of that on the exterior. Numerous small ramps may have been erected at various stages of construction, so that the interior chambers could be built above the core construction and completed before the surrounding pyramid precluded access. (Later, entrance through the passage on the north face, via a supply ramp, would be possible.) To expedite construction, many of the stones were smoothed and sized on the ground outside. The roof slabs of the King’s Chamber were numbered as well, so that workers inside could position them easily and quickly.

When King Khufu died, his divine body was washed and purified at the valley temple and then mummified, a ritual that may have taken several months. (An inscription at Queen Mersyankh’s tomb in the eastern cemetery at Giza records an interval of 272 days between death and burial.) There followed a ceremony called The Opening of the Mouth, a magic rite performed on the burial day that would allow the King to speak once more and enjoy the offerings in the life to come. The mummy was carried to its luminous white tomb and laid within, the entrance closed forever and concealed behind casing stones.

Now cults of royal priests, dressed in white robes, began rites and services that did not end until Ptolemaic times. They heaped the altars with flowers, presented offerings each day, and filled the temple halls with their sacred hymns and prayers.

About Karen Hill

Karen Hill is a freelance writer, editor, and columnist. Born in New York, her work has appeared in the Examiner, Yahoo News, Buzzfeed, among others.

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