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. Tradition, revelation, time, all had lost their influence. The traditions of European mythology, the revelations of Asia, the time-consecrated dogmas of Egypt, all had passed or were fast passing away. And the Ptolemies recognized how ephemeral are forms of faith. But the Ptolemies also recognized that there is something more durable than forms of faith, which, like the organic forms of geological ages, once gone, are clean gone forever, and have no restoration, no return. They recognized that within this world of transient delusions and unrealities there is a world of eternal truth. That world is not to be discovered through the vain traditions that have brought down to us the opinions of men who lived in the morning of civilization, nor in the dreams of mystics who thought that they were inspired. It is to be discovered by the investigations of geometry, and by the practical interrogation of Nature. These confer on humanity solid, and innumerable, and inestimable blessings. The day will never come when any one of the propositions of Euclid will be denied; no one henceforth will call in question the globular shape of the earth, as recognized by Eratosthenes; the world will not permit the great physical inventions and discoveries made in Alexandria and Syracuse to be forgotten. The names of Hipparchus, of Apollonius, of Ptolemy, of Archimedes, will be mentioned with reverence by men of every religious profession, as long as there are men to speak. THE MUSEUM AND MODERN SCIENCE. The Museum of Alexandria was thus the birthplace of modern science. It is true that, long before its establishment, astronomical observations had been made in China and Mesopotamia; the mathematics also had been cultivated with a certain degree of success in India. But in none of these countries had investigation assumed a connected and consistent form; in none was physical experimentation resorted to. The characteristic feature of Alexandrian, as of modern science, is, that it did not restrict itself to observation, but relied on a practical interrogation of Nature. CHAPTER II. THE ORIGIN OF CHRISTIANITY.--ITS TRANSFORMATION ON ATTAINING IMPERIAL POWER.--ITS RELATIONS TO SCIENCE.