that the Nile rose when the sun
appeared under Sirius, and began to fall when it neared the
constellation Libra. This impelled them to make astronomical
observations and to measure time.

To preserve water for the whole year, they dug throughout their country
a network of canals many thousand miles in length. To guard against
excessive waste of water, they built mighty dams and dug reservoirs,
among which the artificial lake Moeris occupied three hundred square
kilometers of surface and was fifty-four meters deep. Finally, along
the Nile and the canals they set up a multitude of simple but practical
hydraulic works; through the aid of these they raised water and poured
it out upon the fields; these machines were placed one or two stories
higher than the water. To complete all, there was need to clear the
choked canals yearly, repair the dams and build lofty roads for the
army, which had to march at all seasons.

These gigantic works demanded knowledge of astronomy, geometry,
mechanics, and architecture, besides a perfect organization. Whether
the task was the strengthening of dams or the clearing of canals, it
had to be done and finished within a certain period over a great area.
Hence arose the need of forming an army of laborers, tens of thousands
in number, acting with a definite purpose and under uniform direction,
an army which demanded many provisions, much means, and great auxiliary
forces.

Egypt established such an army of laborers, and to them were due works
renowned during ages. It seems that Egyptian priests or sages created
this army and then drew out plans for it, while the kings, or pharaohs,
commanded. In consequence of this the Egyptians in the days of their
greatness formed as it were one person, in which the priestly order
performed the role of mind, the pharaoh was the will, the people formed
the body, and obedience gave cohesion.

In this way nature, striving in Egypt for a work great, continuous, and
ordered, created the skeleton of a social organism for that country as
follows: the people labored, the pharaoh commanded, the priests made
the plans. While these three elements worked unitedly toward the
objects indicated by nature, society had strength to flourish and
complete immortal labors.

The mild, gladsome, and by no means warlike Egyptians were divided into
two classes, earth-tillers and artisans. Among earth-tillers there must
have been owners of small bits of laud, but generally eart