nations learned from the boastful priests of occult science. Whatever was known of real value among the ancients, is due to the earnest inquiries of the Greeks. [Sidenote: Researches of the Greeks.] And yet their researches were very unsatisfactory until the time of Hipparchus. The primitive knowledge, until Thales, was almost nothing. The Homeric poems regarded the earth as a circular plain, bounded by the heaven, which was a solid vault or hemisphere, with its concavity turned downwards. And this absurdity was believed until the time of Herodotus, five centuries after; nor was it exploded fully in the time of Aristotle. The sun, moon, and stars, were supposed to move upon, or with, the inner surface of the heavenly hemisphere, and the ocean was thought to gird the earth around as a great belt, into which the heavenly bodies sunk at their setting. [Footnote: _Il_., vii. 422; _Od_., iii. i. xix. 433.] Homer believed that the sun arose out of the ocean, ascending the heaven, and again plunging into the ocean, passing under the earth, and producing darkness. [Footnote: _Il_. viii. 485.] The Greeks even personified the sun as a divine charioteer driving his fiery steeds over the steep of heaven, until he bathed them at evening in the western waves. Apollo became the god of the sun, as Diana was the goddess of the moon. But the early Greek inquirers did not attempt to explain how the sun found his way from the west back again to the east. They merely took note of the diurnal course, the alternation of day and night, the number of the seasons, and their regular successions. They found the points of the compass by determining the recurrence of the equinoxes and solstices; but they had no conception of the ecliptic--of that great circle in the heaven, formed by the sun's annual course, and of its obliquity when compared with the equator. Like the Egyptians and Babylonians, they ascertained the length of the year to be three hundred and sixty-five days; but perfect accuracy was wanting for want of scientific instruments, and of recorded observations of the heavenly bodies. The Greeks had not even a common chronological era for the designation of years. Thus Herodotus informs us that the Trojan War preceded his time by eight hundred years: [Footnote: _Il_, ii. 53.] he merely states the interval between the event in question and his own time; he had certain data for distant periods. Thus the Greeks reckoned dates from the Trojan War, and the Romans from the building of their city. And they divided the year into twelve months, and introduced the intercalary circle of eight years, although the Romans disused it afterwards until the calendar was reformed by Julius Caesar. Thus there was no scientific astronomical knowledge worth mentioning among the primitive Greeks.