Such were the precautions taken against man: the result witnessed to their efficacy, for the pyramid preserved its contents intact for more than four thousand years.* But a more serious danger threatened them in the great weight of the materials above. In order to prevent the vault from being crushed under the burden of the hundred metres of limestone which surmounted it, they arranged above it five low chambers placed exactly one above the other in order to relieve the superincumbent stress. The highest of these was protected by a pointed roof consisting of enormous blocks made to lean against each other at the top: this ingenious device served to transfer the perpendicular thrust almost entirely to the lateral faces of the blocks. Although an earthquake has to some extent dislocated the mass of masonry, not one of the stones which encase the chamber of the king has been crushed, not one has yielded by a hair’s-breadth, since the day when the workmen fixed it in its place. * Professor Petrie thinks that the pyramids of Gîzeh were rifled, and the mummies which they contained destroyed during the long civil wars which raged in the interval between the VIth and XIIth dynasties. If this be true, it will be necessary to admit that the kings of one of the subsequent dynasties must have restored what had been damaged, for the workmen of the Caliph Al-Mamoun brought from the sepulchral chamber of the “Horizon” “a stone trough, in which lay a stone statue in human form, enclosing a man who had on his breast a golden pectoral, adorned with precious stones, and a sword of inestimable value, and on his head a carbuncle of the size of an egg, brilliant as the sun, having characters which no man can read.” All the Arab authors, whose accounts have been collected by Jomard, relate in general the same story; one can easily recognize from this description the sarcophagus still in its place, a stone case in human shape, and the mummy of Kheops loaded with jewels and arms, like the body of Queen Âhhotpû I. [Illustration: 181b.jpg the interior of the great pyramid]