t the Greeks this council of
Constantinople, with that of Nicasa, as the foundation of their faith.
By this religious policy, Theodosius did much to delay the fall of the
empire. He won the friendship of his Egyptian subjects, as well as of
their Saracen neighbours, all of whom, as far as they were Christian,
held to the Nicene creed. Egypt became the safest of his provinces; and,
when his armies had been recruited with so many barbarians that they
could no longer be trusted, these new levies wrere marched into Egypt
under the command of Hormisdas, and an equal number of Egyptians were
drafted out of the army of Egypt, and led into Thessaly.

When the season came for the overflow of the Nile, in the first summer
after the destruction of the temples, the waters happened to rise more
slowly than usual; and the Egyptians laid the blame upon the Christian
emperor, who had forbidden their sacrificing the usual offerings in
honour of the river-god.

[Illustration: 250.jpg MANFALOOT, SHOWING THE HEIGHT OF THE NILE IN
SUMMER]

The alarm for the loss of their crops carried more weight in the
religious controversy than any arguments that could be brought against
pagan sacrifices; and the anger of the people soon threatened a serious
rebellion. Evagrius the prefect, being disturbed for the peace of the
country, sent to Constantinople for orders; but the emperor remained
firm; he would make no change in the law against paganism, and the fears
of the Egyptians and Alexandrians were soon put an end to by a most
plenteous overflow.

Since the time of Athanasius, and the overthrow of the Arian party in
Alexandria, the learning of that city was wholly in the hands of the
pagans, and was chiefly mathematical. Diophantus of Alexandria is the
earliest writer on algebra whose works are now remaining to us, and has
given his name to the Diophantine problems. Pappus wrote a description
of the world, and a commentary on Ptolemy's _Almagest_, beside a work
on geometry, published under the name of his _Mathematical Collections_.
Theon, a professor in the museum, wrote on the smaller astrolabe--the
instrument then used to measure the star orbits--and on the rise of the
Nile, a subject always of interest to the mathematicians of Egypt, from
its importance to the husbandman. From Theon's astronomical observations
we learn that the Alexandrian astronomers still made use of the old
Egyptian movable year of three hundred and sixty-five days only,