Charles Knight (Wikimedia commons)"The pyramids lying in a vast plain or cemetery, extending from 29° to 30° N. lat., for between 60 and 70 miles, are supposed to be about 69 in number. They are all constructed in a uniform manner. A rectangular sepulchral chamber was first hollowed in the rock, with a passage of sufficient dimensions to admit the sarcophagus, communicating with the surface. Over this was at once erected a cubical course of masonry, which served for the nucleus of the pyramid. If the king died during the year, the masonry was covered with a polished casing in shape of a small pyramid ; if the monarch survived, another course of masonry was added to the height of the nucleus, and the length of the lower stage or base increased by courses of stone on each side. Additions on the same plan continued to be made as long as the king lived, fresh courses being added from year to year. When the monarch died this ceased ; the pyramid was cased by filling up the angles of the masonry with smaller stones, placing oblong blocks one upon another, so as to make a series of steps from the top to the base, and then bevelling off all these stones, commencing from the top downwards, at a uniform angle.
A smooth surface was given to each side of the pyramid, rendering it a perfect triangle, while, owing to each stone overlapping the other, no vertical joint was left. Some differences are observable as to the manner in which the internal walls were either vertical or inclined ; but the general principle is the same in all, and the mode of finishing the pyramid casings corresponds with the description of Herodotus.
The means by which the stones were raised is not known ; but the discovery of hemispherical holes about 8 inches in diameter, that look polished by the turning of a heavy body, have suggested the use of derricks, or similar machines - the employment of scaffolding for the purpose being impossible.
All the pyramids are placed with their sides facing the four cardinal points of the compass, and their entrances are on the north side, somewhere about the centre. Extraordinary precautions were taken to prevent access to the sepulchral chambers ; the passages, made exceedingly narrow, were closed by great blocks of stone or granite portcullises, which closed the passages before the apartment ; and the entrance was not placed in the centre of the elevated masonry, where it could have been easily seen, but in the plain below. (...)
The two largest pyramids were considered by the ancients one of the marvels of the world, and to be, as they actually are, sepulchres ; but many absurd notions have been put forth by moderns as to their object, which has been supposed to have been to protect Memphis from the encroachments of sands, or imitation of Hindu edifices, or to square the circle, or vast reservoirs to purify the waters of the Nile, the burial place of Apis, or the granaries of Joseph.
The best received hypothesis was that the pyramids were for astronomical observation, and that the pole star was seen from the inclined passage, but it has been proved by Sir J. Herschel that the pole star, o Draconis, of the age of Cheops, could never have been seen from the inclined passage. It is, however, generally agreed that the pyramids of this group are all of the age of the 4th dynasty, older than 2000 years b.c."