To the principal dimensions of the Great Pyramid given above, it may be added that the entrance is 55 ft. 8 in. above the base, on the 19th course, which is deeper than the 11 to 14 courses above and below; at present there remain 203 courses, to which must be added 12 to 14 missing. Their average height is nearly 2 ft. 6 in., but they diminish in height—generally speaking, but not uniformly—towards the top. The summit now consists of a platform 32 ft. 8 in. square; so that about 27 ft. is wanting, the present actual height being 454 ft. It contains two chambers above-ground, and one cut in the rock at a considerable depth below the foundations. The passages and chambers are worthy of the mass; all are lined with polished granite; and the ingenuity and pains that have been taken to render them solid and secure, and to prevent their being crushed by the superincumbent mass, raise our idea of Egyptian science higher than even the bulk of the building itself could do. [Illustration: Fig. 1. Fig 2. No. 8. Section of King’s Chamber and of Passage in Great Pyramid. Scale 50 ft. to 1 in. ] Towards the exterior, where the pressure is not great, the roof is flat, though it is probable that even there the weight is throughout discharged by 2 stones, sloping up at a certain angle to where they meet, as at the entrance. Towards the centre of the pyramid, however, the passage becomes 28 feet high, the 7 upper courses of stone overhanging one another as shown in the annexed section (fig. 1), so as to reduce the bearing of the covering stone. Nowhere, however, is this ingenuity more shown than in the royal chamber, which measures 17 ft. 1 in. by 34 ft. 3 in., and 19 ft. in height. The walls are lined and the roof is formed of splendid slabs of Syenite, but above the roof 4 successive chambers, as shown in the annexed section (fig. 2), have been formed, each divided from the other by slabs of granite, polished on their lower surfaces, but left rough on the upper, and above these a 5th chamber is formed of 2 sloping blocks to discharge the weight of the whole. The first of these chambers has long been known; the upper four were discovered and first entered by Colonel Vyse, and it was in one of these that he discovered the name of the founder. This was not engraved as a record, but scribbled in red paint on the stones, apparently as a quarrymark, or as an address to the king, and accompanied by something like directions for their position in the building. The interest that attaches to these inscriptions consists in the certainty of their being contemporary records, in their proving that Khufu was the founder of the Great Pyramid, and consequently fixing its relative date beyond all possibility of cavil. This is the only really virgin discovery in the pyramids, as they have all been opened either in the time of the Greeks or Romans, or by the Mahometans, and an unrifled tomb of this age is still a desideratum.