It forms a rectangular mass, incorrectly orientated, with a variation from the true north of 4 deg. 35', 393 ft. 8 in. long from east to west, and 352 ft. deep, with a height of 159 ft. 9 in. It is composed of six cubes, with sloping sides, each being about 13 ft. less in width than the one below it; that nearest to the ground measures 37 ft. 8 in. in height, and the uppermost one 29 ft. 9 in. It was entirely constructed of limestone from the neighbouring mountains. The blocks are small, and badly cut, the stone courses being concave to offer a better resistance to downward thrust and to shocks of earthquake. When breaches in the masonry are examined, it can be seen that the external surface of the steps has, as it were, a double stone facing, each facing being carefully dressed. The body of the pyramid is solid, the chambers being cut in the rock beneath. These chambers have been often enlarged, restored, and reworked in the course of centuries, and the passages which connect them form a perfect labyrinth into which it is dangerous to venture without a guide. The columned porch, the galleries and halls, all lead to a sort of enormous shaft, at the bottom of which the architect had contrived a hiding-place, destined, no doubt, to contain the more precious objects of the funerary furniture. Until the beginning of this century, the vault had preserved its original lining of glazed pottery. Three quarters of the wall surface were covered with green tiles, oblong and slightly convex on the outer side, but flat on the inner: a square projection pierced with a hole, served to fix them at the back in a horizontal line by means of flexible wooden rods. [Illustration: 356. jpg ONE OF THE CHAMBERS OF THE STEP-PYRAMID, WITH ITS WALL-COVERING OF GLAZED TILES.1] 1 Drawn by Faucher-Gudin, from the coloured sketch by Sogato. M. Stern attributes the decoration of glazed pottery to the XXVI '' dynasty, which opinion is shared by Borchardt. The yellow and green glazed tiles hearing the cartouche of Papi I., show that the Egyptians of the Memphite dynasties used glazed facings at that early date; we may, therefore, believe, if the tiles of the vault of Zosiri are really of the Saite period, that they replaced a decoration of the same kind, which belonged to the time of its construction, and of which some fragments still exist among the tiles of more recent date.