by giving it two cylinders. There, too, the first steam-engine
worked. This also was the invention of Hero, and was a reaction
engine, on the principle of the eolipile. The silence of the
halls of Serapis was broken by the water-clocks of Ctesibius and
Apollonius, which drop by drop measured time. When the Roman
calendar had fallen into such confusion that it had become
absolutely necessary to rectify it, Julius Caesar brought
Sosigenes the astronomer from Alexandria. By his advice the lunar
year was abolished, the civil year regulated entirely by the sun,
and the Julian calendar introduced.

The Macedonian rulers of Egypt have been blamed for the manner in
which they dealt with the religious sentiment of their time. They
prostituted it to the purpose of state-craft, finding in it a
means of governing their lower classes. To the intelligent they
gave philosophy.

POLICY OF THE PTOLEMIES. But doubtless they defended this policy
by the experience gathered in those great campaigns which had
made the Greeks the foremost nation of the world. They had seen
the mythological conceptions of their ancestral country dwindle
into fables; the wonders with which the old poets adorned the
Mediterranean had been discovered to be baseless illusions. From
Olympus its divinities had disappeared; indeed, Olympus itself
had proved to be a phantom of the imagination. Hades had lost its
terrors; no place could be found for it.

From the woods and grottoes and rivers of Asia Minor the local
gods and goddesses had departed; even their devotees began to
doubt whether they had ever been there. If still the Syrian