A sepulchral chamber was first excavated in the rock, and during the life of the king who was to repose within it, the work of building the pyramid was pressed forward. It was generally completed before he died, and therefore he had the consolation of knowing that he would not be kept waiting around for his tomb to be constructed. The structure was made over this chamber, an elegant coffin of stone being first placed within it. A passage-way about four feet high and three feet wide was kept open, so that the body of the king could be carried to the sepulchral chamber when the proper time arrived for depositing it in its coffin. The pyramid was practically solid, as the chamber and passages leading to it were the only hollow spaces. The sides of the pyramids were directed to the four cardinal points of the compass, and their exactness in this particular leads to the supposition that the ancients were acquainted with the principles of surveying as practised by modern engineers. [Sidenote: CONSTRUCTION OF THE PYRAMIDS.] The pyramids were constructed of red granite from quarries at Assouan, and other points of the Nile, and of a hard limestone from quarries at Makotam and Tourah. The blocks were very large, and it must have required a vast amount of mechanical power and engineering skill to quarry them and move them to the places where they are now found. Many engineers think that the Egyptians must have possessed some mechanical power which has been lost and become unknown to the people of the present century. Especially is this the case with the huge stones at the top of the pyramids, where the number of persons who could work must have been very small for want of room. Other engineers say that the ordinary derrick on a large scale would have been sufficient for the purpose, and it is pretty certain that this instrument was used, as holes have been found in the stones, where it is supposed the feet of the derricks were placed. Others think that the blocks were moved by human power, of which the kings had an unlimited quantity at their command. One theory is, that as fast as the courses of stone in a pyramid were laid, the earth was piled around it so as to form an incline, where the blocks could be slowly rolled. When the last course, at the top, was laid, the pyramid would have the appearance of a hill with gradually sloping sides. The earth could then be removed, and when it was all carried away the pyramid would stand as it was intended to stand. It is true that this mode of work would require an immense force of men; but what did the kings of Egypt care for the toil of their subjects? The kings owned the land and the people, and could do as they pleased with either. [Sidenote: THE PYRAMID OF CHEOPS.]