These diagrams illustrate the first stages of setting corner casing blocks and the first blocks to either side. They all show the northwest corner of a pyramid, though the point of view alternates from looking southeast (straight on at the corner, I and III), to northeast (II and IV). Steps 1 to 16 are the same on either side of the corner block.
10 First normal block on either side moved up to join with corner block. Extra dressed stone on joint face protrudes above and in front of join with corner block.
11 Extra stock on front faces of first normal blocks bevelled away from slope line as marked and bevelled on joint faces of corner block.
1 Corner block moved above its setting position on rollers. Only the underside is dressed.
2 Side joint faces of corner block dressed.
3 First normal blocks moved in on each side of corner block with undersides only dressed. Side joint faces dressed parallel with matching joint face of corner block. Exact join controlled by measuring with cord.
4 Corner block set down off rollers into its final position.
5 Measurement made from outside reference line (for first course at base only) to mark pyramid baseline on joint faces of corner block.
6 Slope (rise 14 units, run 11 units) marked on joint faces of corner block, using either a plumb line or set square made
Mth the correct angle, placed against the vertical smoothed face of block.
Extra stock on front of block bevelled away from slope line. Corners themselves (as opposed to joint faces of corner blocks) left unbevelled so as not to obliterate the extension of the pyramid face line.
7 Pyramid face line markca on top surface of corner block. Top surface dressed along outside of pyramid fa lines.
8 Second normal block on each side moved in.
9 Side joint faces cut paralh with matching joint side of first normal block.
12 Measurement made from outside reference line to mark pyramid baseline on opposite joint face of first normal blocks.
13 Slope (rise 14 units, run
11 units) marked on opposite joint faces of first normal blocks. Extra stock on front of block bevelled away from slope line.
14 Pyramid face line marked on top of block. Top surface dressed along outside of pyramid face lines.
15 Top surface of blocks finely dressed inside pyramid face lines to prepare bed for next course of casing stone.
16 Second normal blocks drawn up to repeat steps 10 to 15.
(Right) To mark the angle of the pyramid slope the builders could either measure in from a plumb line or use a wooden set square made at the required angle.
Controls marked on the core masonry
'I'he masonry of these step pyramids was clearly itself too roughly constructed to act as a reference for the outer slope. But it is possible that the stepped nucleus was built in advance of the outer casing so that guidelines and reference marks for laying in the casing could have been transferred up and on to its steps. On the southernmost pyramid of Khufu’s queens, GI-c, we have found small holes (c. 5 cm (2 in) diameter) in the corners of the tiers of core masonry blocks that appear to align with the pyramid diagonals, though more mapping work is needed to verify this impression. These could have been for pegs that held the string to mark an inner reference square for measuring out to the pyramid facial lines in the casing. On the other hand, the string might have guided the less precise building of the stepped nucleus, d'his was the purpose of a provisional wall with red painted levelling lines and cubit notations at the northwest corner of Gl-a.
At the back of the chasm on the north face of. VIenkaure’s pyramid, created by Saladin’s son 0th-man (p. 41), the stones of an inner tier still bear a red painted vertical line marking the pyramid centre axis. A host of other marks on the pyramids made by ancient masons, architects and surveyors, remains to be studied. There are crude notches in the core masonry on the centre axes above the entrances of the Bent Pyramid’s satellite pyramid, queen’s pyramid Gl-a, the back side of the west wall of Menkaure’s mortuary temple and the upper masonry block of Khentkawes’s Giza tomb. Similar notches exist in core or backing stones at the corners of Khufu’s and Khafre’s pyramids, where they seem to be alignment markers for core masonry. Without further study, the discussion of the purpose of such marks must remain speculative, but we must look at the evidence that the ancient builders actually left in the stones as we hypothesize how the pyramids might have been built. Of course, as soon as the pyramids of Khufu and Khafre rose above the bedrock massif left in their cores, the builders could have controlled for squareness by measuring the diagonals.
Designing slope stone by stone
At any given point during construction, what the ancient builders were probably confronted with was a large masonry square, within which were •hambers and passageways in the case of Khufu, packed around with core masonry and then the )uter casing. The core may have risen somewhat in advance of the casing and packing stones.
While there may have been distant sight refer-¦nce markers and controls marked on the core, the ¦vidence indicates that the ancient masons designed the slope of the pyramid face into the ndividual casing stones as they were cut and cus-:om fitted one to another. As the casing blocks were brought into their intended positions, only the bottom had been dressed. Once a casing block had been brought to its place next to its neighbouring stone, the still-exposed opposite and top join faces would be dressed smooth. But before these faces were obscured by other stones, they would be inscribed with a line marking the position of the sloping face - perhaps by measuring up and in set increments from a plumbed line or using a wooden set square of the correct angle. Then, crucially, the extra stone on the front face of the casing block was chamfered or bevelled as far as this line.
At the final stage in the construction process, when the ancient masons removed the ramps and dressed down the face of the pyramid, they knew precisely how much stone to shave away to achieve the smooth, flush plane of the pyramid face: they simply stopped at the point where the seams between adjacent stones closed up to a fine joint.
Evidence that this procedure was used can be seen in the granite lower courses of Menkaure’s pyramid. These were left partially undressed, probably when building halted at the king’s death, and so still carry the extra stock of stone that would have been cut away. Where stones have fallen away, the blocks still show the line marking the slope of the pyramid face on their side and top joint faces.
Rise and Run
(Below) The granite lower courses of Menkaure’s pyramid at Giza tvere left partially undressed and so the extra stock of stone was never cul aivay to achieve the pyramid’s final smooth face. (Inset) I am pointing to the line and bevel that guided the trimming of the pyramid face from the extra stock left on the casing blocks.
Surviving casing blocks at the top of Khafre’s pyramid (top) are not quite flush - perhaps because they were cut before being put into place due to the problems of working in the restricted space at the top of the pyramid. There are different theories to explain how the topmost courses were laid in these difficult conditions. One suggestion (above left) is that there was a series of small ramps running around the very top; another consists of a wooden platform at the top of a large stone stairway (above right).
World History
