engraved on monuments, written on papyrus, and buried in tombs,
or under the ruins of temples, hence, as has been said elsewhere,
much of it remained hidden until nineteenth century research
brought it to light. Even at the present time many inscriptions
are still undeciphered.

Geometry originated with the Egyptians, and their knowledge of
hydrostatics and mechanics (shown in the building of the
Pyramids), and of astronomy and medicine, is of remotest
antiquity. The Greeks borrowed largely from them, and then became
in turn their teacher. The Egyptian priests, from the earliest
age, must have preserved the annals of their country; but they
were destroyed by Cambyses (500 B.C.), who burned the temples
where they were stored.

In the fourth century B.C., Egypt was conquered by Alexander the
Great, who left it under the rule of the Ptolemies. The next
century after the Alexandrian age the philosophy and literature
of Athens was transferred to Alexandria. The Alexandrian library,
completed by Ptolemy Philadelphus, in the third century before
Christ, was formed for the most part of Greek books and it also
had Greek librarians; so that in the learning and philosophy of
Alexandria at this time, the Eastern and Western systems were
combined. During the first century of the Christian era Egypt
passed from the control of the Greek Kings to that of the Roman
Emperors, under whom it continued to flourish. In the seventh
century the country was conquered by the Saracens, who burned the
great Alexandrian library. Following them came the Arabian
Princes, who protected literature, and revived the Alexandrian
schools, establishing also other seats of learning. But in the