They are constructed of limestone upon a foundation of levelled rock and were originally finished on the outside with massive blocks of polished stone. The entrance is on the north side by a passage, which first descends and then rises to the principal chamber, which contained the king’s sarcophagus. This was lined on the east and west sides with immense stones, supporting several layers of horizontal blocks, crowned with a gable, formed of stones, which are so placed that they exert no thrust upon the stones below. A similar gable formed the ceiling of the Queen’s Chamber, which is situated at a lower level, while at a still lower level is a third chamber. The statues and sculptured reliefs, discovered in the pyramids and mastabas of the Fourth to Sixth Dynasties, exhibit not only a highly developed skill in the cutting of hard and soft stone, and ivory and wood and in beating copper but also remarkable expression of character. The minute statuette in ivory of Cheops, though the face is only about a quarter of an inch in length, is a portrait of extraordinary force, and the life-size figure of Chephren, carved in hard diorite, is equally distinguished for its serenity and power. The character of all the sculpture, even of low-reliefs of everyday scenes, is but little naturalistic, being impressed with a certain grandeur, as of something inevitable and immutable. The earliest example of wall-painting appears at Sakkarah in the Pyramid of Onas, the last king of the Fifth Dynasty; where, amid the record of ritual observances, is depicted the grinding of the god’s bones to make bread. =Mastabas.=--From the methods of burial were also developed the type of the =mastabas= or tombs of the royal family, priests, and chieftains, which were erected at =Sakkarah=, near Memphis, during the Fourth, Fifth, and Sixth Dynasties. The name is derived from the Arabian term for a bench, the familiar type of which is a seat, supported upon boards that slope inward. Similarly the tomb has a flat roof and _battered_, or inward sloping, walls of masonry. It is entered usually on the east side, by a passage that descends to the Chamber of Offering, which contains, to hold the offerings, a sculptured table. Near it a vertical pit, or well, from forty to fifty feet deep, is sunk in the solid rock, communicating with the mummy chamber. Another hidden chamber, often connected with the Chamber of Offering, is known as the _Serdab_, which was intended to serve as a home for the deceased’s Ka or “double.” It contained a statue of the deceased and sometimes a model of his home and representations of his occupations during life. Thus, in the =Mastaba of Thy=, with a view to inducing the Ka to overlook the break that has occurred in the life of the deceased, the reliefs depict harvest operations, ship-building scenes, the arts and crafts of the period, the slaughtering of sacrificial animals and Thy himself traversing the marshes in a boat.