Egyptian history really begins with the old kingdom dynasties, about ten thousand years ago. The tombs of Abydos have furnished material for accounts of this early period. There were eight powerful kings in the first dynasty and all of them contributed to the advancement of civilization. Abydos, and later Memphis, were their principal cities. They ruled in great luxury and were patrons of the arts and sciences. The art works, sculptures, and carvings in ivory and ebony of this era speak in eloquent terms of the taste and high mental powers of the people. Modern museums are well supplied with relics of those times, which illustrate the degree of civilization attained by the Egyptians at the beginning of their history better than any written account. The early Egyptians adopted the sciences, arts and customs of the Babylonians. With these as a basis the priests and learned men experimented and made many independent researches and discoveries. The pyramids, erected near Cairo 3000 B. C., indicate the high degree of culture which the early Egyptians had attained. These renowned monuments to the kings were scientifically designed and constructed to exist for all time. In order to contribute to their usefulness, they were planned so as to exhibit correct geometrical forms and indicate the cardinal points of the compass and the positions of certain astronomical bodies. The details of their construction disclosed much mathematical, geometrical and physical knowledge, and their actual building called for not only an all-around mechanical skill but a high degree of engineering ability. They were constructed of various materials. Some large granite blocks were used in the outside walls and these were brought from the upper Nile. They were towed down the river on barges and were lifted into the positions in which they are found to-day. Various mortars and mortar mixtures were employed in binding the brickwork and masonry. These called for a good knowledge of chemistry and physics. The arches and sloping walls of some of the larger pyramids show how well the architects and engineers of the day knew their professions. With similar means in their possession, the best professional men of the present day would find it difficult to get such splendid results.