The other two pyramids, those nearest the cultivation, are of very different appearance. They are half-ruined, they are black in colour, and their whole effect is quite different from that of the stone pyramids. For they are built of brick, not of stone. They are pyramids, it is true, but of a different material and of a different date from those which we have been describing. They are built above the sepulchres of kings of the XIIth Dynasty, the Theban house which transferred its residence northwards to the neighbourhood of the ancient Northern capital. We have, in fact, reached the end of the Old Kingdom at Sakkâra; at Dashûr begin the sepulchres of the Middle Kingdom. Pyramids are still built, but they are not always of stone; brick is used, usually with stone in the interior. The general effect of these brick pyramids, when new, must have been indistinguishable from that of the stone ones, and even now, when it has become half-ruined, such a great brick pyramid as that of Usertsen (Senusret) III at Dashûr is not without impressiveness. After all, there is no reason why a brick building should be less admirable than a stone one. And in its own way the construction of such colossal masses of bricks as the two eastern pyramids of Dashûr must have been as arduous, even as difficult, as that of building a moderate-sized stone pyramid. The photograph of the brick pyramids of Dashûr on this page shows well the great size of these masses of brickwork, which are as impressive as any of the great brick structures of Babylonia and Assyria. [Illustration: EXTERIOR OF THE SOUTHERN BRICK PYRAMID OF DASHÛR: XIITH DYNASTY. Excavated by M. de Morgan, 1895. This is the secondary tomb of Amenemhat III; about 2200 B.C. The XIIth Dynasty use of brick for the royal tombs was a return to the custom of earlier days, for from the time of Aha to that Tjeser, from the 1st Dynasty to the Hid, brick had been used for the building of the royal mastaba-tombs, out of which the pyramids had developed.