The Arch. 79 of tombs, while those left to us by the eighteenth dynasty and its successors are of vast dimensions, such as the great Theban temples, and have annexes comprising buildings erected for a vast variety of purposes. Groined vaults were unknown to the Egyptians, but almost every variety of arch and of plain vault is to be found in the country. The semicircular arch is more frequently met with than any other. That which exists in an old tomb at Abydos has been already figured (Fig. 44), we shall give two more examples, dating from the Sait epoch. The illustration below (Fig. 45), represents the gate in the encircling wall of one of the tombs in the valley of El-Assassif, at Thebes. The wall diminishes gradually in thickness from sixteen feet eight inches at the bottom to nine L^^ ^- l S Fig. 45. — Arch in El-As-assif, pre ent condition ; from Lep-ius. feet nine inches at the top, both faces being equally inclined. This latter feature is a rare one in Egypt, the slope being as a rule confined to the external face. In order to show it clearly we have interrupted the wall vertically in our illustration, isolating the part in which the arch occurs (Fig. 46), and restoring the summit. The arch itself is formed of nine courses of brick. The sarcophagus in " Campbell's Tomb "' is protected by a plain cylindrical vault of t'our courses (see Fig. 200, vol. i.), which covers a polygonal vault formed of three large slabs. Both vaults are pierced by a narrow opening, which may, perhaps, have been intended to allow the scents and sounds of the world above to reach the occupant of the sarcophagus. Its arrangement is so careful that it must have had some important purpose to fulfil. In the group of ruins which surrounds the back parts of the Ramesseum (see p. 379, vol. i.) there are vaults of various kinds. A
