The second great pyramid, built by the successor of Cheops, Chephren (Sophris), seems not to have been so regular in its interior arrangement. The third, that of Chephren’s successor, Mykerinos (Menkera), is of the most beautiful execution. The unevenness of the ground was so considerable that a substructure of masonry was here necessary. The entire kernel is of rectangular courses of stone, and, with the exception of the exterior casing, is built in the form of steps. This manner of construction was employed in most of the pyramids, but is here particularly noticeable. The casing of granite, highly polished, is still partly intact; the joints of its stones are scarcely perceptible, and are not wider than the thickness of a sheet of paper. The mechanical excellence of all these pyramids is indeed wonderful; they remain as a marvellous proof of the constructive ability of man in ages far anterior to known periods of the world’s history. Nor are they mere piles of masonry which could have been erected by an enslaved people without the guidance of skilled and thoughtful designers. The arrangement of the passages, of the chambers and their portcullises, of the quarried stone and polished revetment, was admirably adapted to the required ends. In the third pyramid two corridors have been found, one above the other. The upper, opening within from the first chamber, at some height above the floor, does not reach the exterior surface, but ends suddenly against the unpierced outside casings. This peculiarity is explained by, and in turn gives weight to, the statement that this pyramid, as originally built by Mykerinos, was considerably smaller than it is at present, measuring, according to the end of the unfinished upper corridor, 54.86 m. on the side of the plan, and 42.20 m. in vertical height. Nitocris, the last queen of the sixth dynasty, prepared the pyramid to serve also as her own monument by adding courses of stone which increased these dimensions to 117.29 and 66.75 m. respectively. But as the original entrance, by the prolongation of its inclined line outward, would thereby have opened much too high above the ground, a new corridor beneath the first was rendered necessary. The second chamber, which probably once contained the sarcophagus of the queen, was found entirely plundered. The third and lowest, better protected, had been opened; but in it there still remained in position a magnificent coffer of basalt. The exterior of this sarcophagus was sculptured with lattice-work in imitation of a palace-like structure with portals. Fragments of the wooden coffin, with carved hieroglyphics, once within it, and of the mummy itself, were flung about the room. The sarcophagus, of the greatest value as illustrating the architectural forms of its time, sank in the Mediterranean with the ship which was carrying it away to England. The mummy and the lid of the coffin are in the British Museum.