of these walls was filled in, and thus a kind of terrace, or huge rectangular block, was obtained (Fig. 138), which served as the core for a new pyramid (Fig. 139). This again disappeared under a pyramid of larger section and gentler slope (Fig. 140), whose sides reached the ground far beyond the foundations of the terrace. In the case of a long reign this operation might be repeated over
Fig. 136—142. — Successive states of a pyramid, according to the system advocated in Bædeker's Guide.
and over again (Figs. 140 and 142). A large pyramid would thus be composed of a series of pyramidal envelopes placed one upon another. The mummy-chamber was either cut in the rock before the laying of the first course of stone, or it was contrived in the thickness of the masonry itself; as the casing of stone went on increasing in thickness, galleries were left for ventilation and