It is difficult to realize the vast size of these piles, and we can do so only by comparing them to things with which we are familiar. The base of the largest pyramid covers thirteen acres of ground, solid masonry; it was originally 482 feet high. Since it is almost one solid mass of stone, it is not difficult to credit the statement of Herodotus that it took 100,000 men twenty years to build it, an additional ten years being necessary to quarry the stone and bring it to the chosen site. "The tradition recorded by Herodotus as to the labor employed, is so entirely reasonable for the execution of such work, that we cannot hesitate to accept it. It is said that a hundred thousand men were levied for three months at a time (i. e. during the three months of the inundation, when ordinary labor is at a standstill); and on this scale the pyramid-building lasted twenty years." How complete must have been the organization of a government which could promote such an extensive project as this! How entirely were the resources of the empire at the disposal of the king when free citizens could be impressed to satisfy the vanity of the proud pharaoh! To have supported 100,000 non-producing men must of itself have taxed the treasury. The rulers who built these majestic tombs wished to make their names immortal, as well as to preserve their bodies from harm and decay. This first they certainly accomplished, but in light of modern investigation, when each stone lifted into place has been estimated to have cost at least one human life, these proud pharaohs elicit less admiration and commendation than they doubtless thought to win. Three kinds of stone were used in the construction of these pyramids. The inner part, or core, was formed of material plentiful near the building site. This was a spongy limestone that was not durable if exposed to the elements, but adequate when covered with other stone. The successive layers, put on in the form of steps, were of stone brought from across the river, having been quarried in the mountains on the east. It has been conjectured that a causeway was laid from the mountains to the side of the pyramid, and that blocks of stone were dragged by men this distance. Finally, the beautiful granite used for outer casing was found near the southern border of Egypt, floated down the stream when the water was high, and having been polished like a mirror, was fitted over the rougher stone. 2,300,000 blocks, averaging two and one-half tons each, were used for the construction of the largest pyramid.