234 A History of Art in Ancient Egypt. The upper part, which still remains in place, is composed of a hard cement formed of chalk, gypsum, and pieces of burnt brick. They may have wished to obtain the parti-coloured effect of which Philo speaks, by making simultaneous use of granite and concrete, and it is quite possible that yet other materials entered into the composition of the casing.^ In other pyramids we find different combinations again. In the double-sloped erection at Dashour, the courses of casing stones are vertical instead of horizontal,- while a brick pyramid - — the most northern — in the same locality, was covered with slabs of limestone, fixfed, no doubt, with mortar. Sometimes we find the revetment in a state of semi-completion ; the blocks in place, and cut to the proper angle, but without their final polish. Such is the case with the Second Pyramid, upon which blocks of granite are to be found which are still rough in face. It would seem that the patience required for the minute completion of such a terribly long and tedious piece of work was not forthcoming. But we ought in fact to be surprised, not so much at the unfinished state of a pyramid here and there, but rather that they should ever have been completed. The variety which is so conspicuous in the architectural con- struction of the pyramids is also to be found in their epigraphy. The first explorers of the Pyramids of Gizeh were surprised at the absence of all inscriptions beyond the masons' marks ; the silence of those enormous structures seemed amazing ; but soon Colonel Vyse discovered in the pyramid of Mycerinus the sarcophagus of that king, and the mummy case, now in the British Museum, which bears an inscription of some length. Recent discoveries, too, of which full details are yet wanting, prove that some of the pyramids contained long texts, which contain the names of kings and other information which is of sfreat imoortance to the historian of the Egyptian religion. In 1879 and 1880, Mariette caused three pyramids at Sakkarah to be opened, which until then had ' The determination to use a concrete such as that described affords a good reason for the prismatic shape of the granite blocks used in the lower courses. It would evidently be easy enough to cover the pyramid with a coat of cement — working downwards — if its surface did not greatly overpass the salient angles of the steps, while the difficulty would be enormously increased if the coat were to have a considerable thickness of its own independently of the pyramid, like the casing shown in Fig. 155. — Ed. - Descripiion de fEgyp/c, Antiquith, vol. v. p. 7.
