a. The Clearing of the Rock-surface for Foundations 
As explained in Chapter II, the nucleus cemeteries of cores are six in number, four in the Western Field, one in the Eastern Field, and one south of the Cheops pyramid. All these cores are founded on the surface of the grey nummulitic limestone which forms the promontory on which the Giza Necropolis was built. In the case of the four cemeteries of the Western Field and that of the Eastern Field,

the rock-surface has been cleared, either at one operation or in successive areas, before the construction of the cores, and the streets were afterwards filled in with masons’ rubbish to form a livingfloor about on a level with the floors of the chapels. The dumping-places of the geological rubbish and sand removed in the clearing operations cannot now be definitely ascertained. In the excavation of the small Wady Cemetery, north of G 2000, we discovered that this cemetery had been covered by the debris cleared away when that mastaba was built. Probably the debris cleared from Cem. G 1200 and Cem. G 2100 was also dumped out to the north. That from Cem. G 4000 seems, on the other hand, to have been piled south of the massive wall which bounds that cemetery on the south. A certain mount of rubbish was undoubtedly used in the filling of the cores.
The cores south of the First Pyramid, excavated by Professor Junker, Cem. G I S, were also founded on rock, but according to Junker’s observations were built in cleared areas only a little larger than the projected core, or in foundation trenches. This fact has a special significance for the dating of that cemetery.
b. Kinds of Building Stone used in Core-mastabas
The stone used in all the cores of these six cemeteries was of local origin. The fine white limestone from the Mokattam Hills was used, however, in the casing, the stone chapel, and the lining of the burial-chamber,

which were all constructed after the cores. The local stone is of the two chief varieties of coarse nummulitic limestone, a softer yellow-drab stone, and a harder grey stone, and both of these occur in several qualities. In general the stone blocks used in each core are of fairly uniform quality and obviously from the same quarry. But a number of the massive cores of later construction contain stones of both the yellow-drab and the grey stone.
The yellow-drab stone occurs as follows:
(I) In the 10 cores of Cem. G 1200, of a harder quality; core type II a.
(2) In the 5 western cores of Cem. G 2100, also of a hard quality; core types II a and II b.

(3) In the 5 earliest cores of Cem. G 4000, of hard quality; type II b.
(4) In the facing of 4 massive cores, harder quality; type III.
(5) In the 6 eastern mastabas of Cem. G 2100, softer quality; type II a.
(6) In G 4860 and the 25 cores of the Echelon Cemetery, poorer stone; type II a, usually with 2 shafts.
(7) In the Eastern Field, in the masonry filling the old Cheops quarry east of his temple to form the foundation of the causeway corridor;
(8) In the 5 massive cores added to the cemetery of twin-mastabas in the Eastern Field; a softer quality mixed with grey blocks.
The hard nummulitic stone occurs as follows :
(I) In the core-work of the 3 large and 7 small pyramids, in the core-walls of the temples of those pyramids, and in the causeways.
(2) In the great boundary wall south of the Western Field.
(3) In the mastaba cores of Cem. G 4000, excluding the first 5 and the last cores; 46 cores of type IV i.
(4) In the 12 original cores of the Eastern Field; type IV i.
(5) In the reconstructed cores of the 8 twin-mastabas of the Eastern Field; type IV ii and IV ii + IV iii.
(6) In the additional core-work added to 3 mastabas of type II a in Cem. G 1200, and to 2 mastabas of type II b in Cem. G 4000.
(7) In the 5 additional cores added to the cemetery of twin-mastabas, mixed with yellow-drab stone; type IV iii and IV iv.
(8) In the cores of Cem. G I S, of which some contain a mixture of yellow stone.
It is obvious that the various beds of stone were being worked practically simultaneously during the construction of the nucleus cemeteries.
c. Method of Construction of the Core-mastabas
The construction of each core appears to have been carried out in approximately the same manner. The preparation of the surface for the first course is difficult to determine without tearing down the retaining wall, but apparently an emplacement is roughly dressed in the rock surface. On this was set the first course of the retaining wall and the space within immediately filled with rubbish to the top of the course. The top of the course was roughly dressed and the second course set on top of the first and again filled in behind. Thus the construction of the courses and the filling of the interior proceeded practically pari passu both for the small-course cores and for the massive cores. The casing of the shaft above the rock was carried out simultaneously course by course with the retaining wall and with stone of the same size and quality. In the case of the solid mastabas of type II b the solid stone-work was built pari passu with the retaining wall. The joining of the stones in the small-course retaining wall was moderately good and showed a certain amount of chinking with coarse pinkish plaster, so that the exterior appearance of all cores of type II a, II b, and III was that of a well-finished wall of stepped vertical courses. In the massive cores, while the courses are well fitted horizontally, the stones in the course are not carefully fitted together. The outward appearance of the whole is not that of a wellfinished structure, and it may be safely assumed that all the cores of type IV were intended to be faced as type III or cased in white limestone.
The mastabas of Dyns. I-III, with the exception of those in the enclosure of the Zoser pyramid, were of c.b. of two types of construction.
I a: The filled mastaba with a retaining wall of c.b. and a filling of sand, gravel, or rubbish; in the largest and most important of the filled mastabas the interior was divided by c.b. walls into compartments which were filled with sand, gravel, or rubbish; from Dyn. I to Dyn. VI.
I b: A similar mastaba, filled solid (or more or less solid) with c.b., roughly laid as headers; private mastabas from the beginning of Dyn. III: both these types were plastered outside with mud which in turn was coated with white plaster. The exception, the mastabas in the enclosure of the Zoser pyramid, are stone-cased rubble cores. The type with rubble-faced core does not appear among the earliest stone mastabas at Giza.
The types of core-mastabas are as follows:
(I) Type II a: a filled mastaba (as I a) with a retaining wall of small drab limestone blocks in lowstepped courses, filled with sand, gravel, rocks, and rubbish; no niches; slab-stela; single burial-shaft, the upper part of which, through the filling of the mastaba, is cased with stone blocks similar to those of the retaining wall; 2-m. burial-shaft (Fig. 1).
Cem. G 1200: 10 mastabas.
Cem. G 2100: 10 mastabas, like those in G 1200.
Cem. G 4000: 1 mastaba: 2 -m. shafts.
Cem. en Echelon: 25 mastabas: 1 or 2-m. shafts.
No examples occur in the Eastern Field, Cem. G 7000.

(2) Type II b: in outward appearance like II a, but filled solid with small stone blocks (cf. I b); no niches; slab-stelae (Fig. 2).
G 4000: 2 2-m. shafts.
G 4150, 4160, 4250, 4260: 1 2-m. shaft: slab-stela.
G 2130: 1 2-m. shaft.
(3) Type III: retaining wall of large blocks of grey nummulitic limestone set in high-stepped courses and filled with gravel and rubbish, or more or less solid with massive blocks; the massive stepped core is faced with small blocks of drab limestone giving the same outward appearance to the core as that of type II a and b;
slab-stela in 2 out of 4.
i: without recess for interior chapel: G 4350, 4140 (Fig. 3).
ii: with recess perhaps broken in massive core, but reconstructed with massive masonry and faced with small-stepped courses : G 2000, G 7410 + G 7420 (Fig. 4).
(4) Type IV: massive core like type III, but without the facing of small blocks; slab-stela in rows 5 and 6 of Cem. G 4000.
i: without recess for the interior chapel: G 4360-4760, G 4450-4850, G 4240-4840. All the remaining
cores in Cem. 4000, except 3 cores altered in Dyns. IV-V. Twelve original cores constructed in Cem. G 7000 and incorporated with alterations in mastabas G 7110 + G 7120 to G 7410 + G 7420 and G 7130 + G 7140 to G 7430 + G 7440. Probably also the IO cores in Cem. G I S (Fig. 5).
ii: massive core-mastabas with recess broken and reconstructed later. The 12 original cores in Cem. G 7000 when they were incorporated in the 8 twin-mastabas of that cemetery and a few mastabas in G I S (Fig. 6).

iv: massive core, the casing of which has been prolonged southwards to include an interior chapel; 7350 (Fig. 8). G 7650, 7530 +40 (Fig. 9).
These core types are used also to designate the finished mastabas which contain those cores.
For the sake of convenience I give here the type designation used for mastabas of other later types, including those of Dyns. V and VI:
(5) Type V: a filled mastaba with a retaining wall consisting of two layers of stone: the outer layer is of fine white limestone dressed to a sloping surface, and supported behind by a nummulitic block;
built course by course and filled in pari passu: interior chapel of type III of white limestone; G 7050 (Fig. I0).
(6) Types-
VI: with interior chapel of type (3) and subsidiary northern niche;
VI a : filled mastaba with grey nummulitic retaining wall of large slabs set sloping and dressed to a sloping  surface; filled with rubbish or more or less solid with massive grey blocks; 2 2-m. shafts.

Examples in Cem. G 7000: the last princely mastabas added to the nucleus cemetery;
G 7550, 7660, 7750, 7760, 7060, 7070, 7810, 7820 (Fig. 11).
VI b: similar form of z-niasonry with or without rubble-faced core.
VI c: as VI b with retaining walls of u- or zu-masonry; no examples.
VI d: as VI b, built of rubble-faced core-work plastered with mud; no examples.
VI e: like VI b, built with retaining walls of c.b., or rubble core cased on one or more faces with c.b., or solid c.b. mastaba; G 1457 (Fig. 12).
(7) Types-
VII : filled mastaba or core-mastaba with interior chapel of type (4).
VII a: constructed of large nummulitic blocks as VI a; G 1031.
VII b: constructed of z-masonry, as VI b; G 1020 (Fig. 13).
VII c: constructed of u- or zu-masonry, as VI c; no example.
VII d: constructed of rubble-faced core-work, as VI d; no example.
VII e: constructed of c.b. as VI e.
(8) Types-
VIII: with interior chapel of type (5), (6), or (7).
VIII a: built of nummulitic blocks of grey stone.
VIII b: built of z-masonry; G 1151.
VIII c: built of u- or zu-masonry; G 1029, G 1047 (Figs. 14, 15).
VIII d: built of rubble-faced core-work ; no examples.
VIII e: built of c.b.
(9) Types-
IX: with exterior chapels of type (8).
IX a: built of grey nummulitic slabs; G 5230.
X bI: built of z-masonry.
IX c: built of z- or zu-masonry.
IX d: built of rubble-faced core-work.
IX e: built of c.b.
(IO) Types-
X: mastaba with niches and open-air chapel; chapel type (9 a, b, or c).
X a: built of grey nummulitic blocks.
X b: built of z-masonry.
X c: built of u- or zu-masonry.
X d: built of rubble, plastered with mud.
X e: built of c.b.
(11) Types-
XI: mastaba with no niches preserved, with exterior open-air chapel type (9 d).
XI a: built of grey nummulitic blocks.
XI b: built of z-masonry.
XI c: built of u- or zu-masonry.
XI d: built of rubble, plastered with mud.
XI e: built of c.b.
These types of cores (types I-VI) bear in themselves certain evidence as to their chronological order. The enlargement of core types I a and I b with additional core-work of type IV iii is decisive as to the order of those types (Fig. 16). The existence of types IV i, ii, and iii with the evidence of the addition of type IV iii to type IV ii in Cem. G 7000 proves clearly the order of these three subtypes.

The use of low-stepped courses of small stones as the facing or retaining walls of types II a, II b, and III draws these three types into one group, for the stone and the construction of the stepped facing walls are clearly similar and are not found outside the Western Cemetery of Cheops (except G 7410 + 7420, of type III). The use of the massive core-work in types III and IV draws these two types together.
All the cores in the Cems. G 1200, G 4000, and G 2100 have one 2-m. shaft except G 2100, G 4000, G 4860, and G 2150. The mastabas with two shafts are derived from twin-mastabas for husband and wife. Four of the one-shaft mastabas of types II a and III have an annex built against the north end to contain the burial-shaft of the lesser member of the pair (husband or wife), a modification of the twin-mastaba type. The two-shaft mastaba arose without doubt out of the twin-mastaba. The earliest examples at Giza, apart from the mastabas with annexes, were the eight twin-mastabas of Cem. G 7000.
As reconstructed, the cores of these northern four consisted each of two original cores of type IV i, joined with massive masonry and remodelled with two recesses for two interior chapels (man and wife).
The shafts as originally planned appear to have been one shaft cased through the filling in each of the original cores of type IV i. This shaft was just north of the place of the offering-chapel in the axis of the core, that is, shaft B in G 7110-7410 and shaft B in G 7120-7420. The B shafts of the northern part of the four twin-mastabas were those actually finished and used for burials as far as they were used (not used in G 7110). The B shaft in the man’s part was never used, but when the two old cores were joined up to form the core of each twin-mastaba, a new shaft was constructed and used north of B shaft. This is the A shaft. The position of the burial-shaft was probably due to a shift in the position of the chapel. The old core had been intended for an exterior chapel close to its southern end. When the twin core was constructed and the new interior chapel built farther north, the new shaft was made in the proper relative position to the new chapel. The chapel of the wife’s part was shifted a little to the south, and thus the old B shaft in the wife’s part was left in a proper relative position and therefore used. The A shaft was not constructed except in G 7110, and that never finished. No A shaft was constructed in the northern part of the other three twin-mastabas. Each of the four southern twin-mastabas had two large shafts both in the original core of the old nucleus cemetery. Added south of this was a large block of massive core-work (type IV iii) with recess for the southern chapel, and containing no shaft (Fig. 17). These mastabas were obviously designed as twoshaft mastabas and enlarged after the construction of the shafts. The peculiar character of the southern twin-mastabas was due apparently to the later date at which they were finished. It will be remembered that only one of them (G 7130 + 7140) was finished with the fine white casing and the two interior chapels which mark the four northern twin-mastabas.