Invention of the steam-engine.  In the Museum of Alexandria, Ctesibius invented the fire-engine.  His pupil, Hero, improved it 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 damsels lamented, in their amorous ditties, the fate of Adonis, it was only as a recollection, not as a reality.  Again and again had Persia changed her national faith.  For the revelation of Zoroaster she had substituted Dualism; then under new political influences she had adopted Magianism.  She had worshiped fire, and kept her altars burning on mountain-tops.  She had adored the sun.  When Alexander came, she was fast falling into pantheism.

On a country to which in its political extremity the indigenous gods have been found unable to give any protection, a change of faith is impending.  The venerable divinities of Egypt, to whose glory obelisks had been raised and temples dedicated, had again and again submitted to the sword of a foreign conqueror.  In the land of the Pyramids, the Colossi, the Sphinx, the images of the gods had ceased to represent living realities.  They had ceased to be objects of faith.  Others of more recent birth were needful, and Serapis confronted Osiris.  In the shops and streets of Alexandria there were thousands of Jews who had forgotten the God that had made his habitation behind the veil of the temple.