IV. THE DECADENCE or SAITIC PERIOD (1000-324 B.C.), comprising the dynasties twenty-one to thirty (Saitic, Bubastid, Ethiopic, etc.), reigning at Sais, Tanis, and Bubastis, and the Persian conquest; a period almost barren of important monuments. (Periods III. and IV. constitute together the period of the NEW EMPIRE, if we omit the Persian dominion.) V. THE REVIVAL (from 324 B.C. to cir. 330 A.D.) comprises the Ptolemaic or Macedonian and Roman dominations. +THE ANCIENT EMPIRE: THE PYRAMIDS.+ The great works of this period are almost exclusively sepulchral, and include the most ancient buildings of which we have any remains. While there is little of strictly architectural art, the overwhelming size and majesty of the Pyramids, and the audacity and skill shown in their construction, entitle them to the first place in any sketch of this period. They number over a hundred, scattered in six groups, from Abu-Roash in the north to Meidoum in the south, and are of various shapes and sizes. They are all royal tombs and belong to the first twelve dynasties; each contains a sepulchral chamber, and each at one time possessed a small chapel adjacent to it, but this has, in almost every case, perished. Three pyramids surpass all the rest by their prodigious size; these are at Ghizeh and belong to the fourth dynasty. They are known by the names of their builders; the oldest and greatest being that of +Cheops+, or Khufu;[1] the second, that of +Chephren+, or Khafra; and the third, that of +Mycerinus+, or Menkhara. Other smaller ones stand at the feet of these giants. [Footnote 1: The Egyptian names known to antiquity are given here first in the more familiar classic form, and then in the Egyptian form.] [Illustration: FIG. 1.--SECTION OF GREAT PYRAMID. a, _King’s Chamber_; b, _Queen’s Chamber_; c, _Chamber cut in Rock_.] The base of the “Great Pyramid” measures 764 feet on a side; its height is 482 feet, and its volume must have originally been nearly three and one-half million cubic yards (Fig. 1). It is constructed of limestone upon a plateau of rock levelled to receive it, and was finished externally, like its two neighbors, with a coating of polished stone, supposed by some to have been disposed in bands of different colored granites, but of which it was long ago despoiled. It contained three principal chambers and an elaborate system of inclined passages, all executed in finely cut granite and limestone. The sarcophagus was in the uppermost chamber, above which the superincumbent weight was relieved by open spaces and a species of rudimentary arch of Λ-shape (Fig. 2). The other two pyramids differ from that of Cheops in the details of their arrangement and in size, not in the principle of their construction. Chephren is 454 feet high, with a base 717 feet square. Mycerinus, which still retains its casing of pink granite, is but 218 feet in height, with a base 253 feet on a side.