Note 16 — INTRODUCTION.

The Greeks derived their knowledge of astronomy from the Egyptians and Chaldeans. According to Plutarch, the sciences began to unfold themselves about the time of Hesiod, the Greek poet, who flourished upwards of nine centuries before the Christian era; but their progress was very slow, until the time of Thales, which was about three centuries later. And although this celebrated philosopher of antiquity rendered himself famous by foretelling an eclipse of the sun, he only predicted the year in which it was to happen. Even this, it is remarked by Mr. Vince (in his invaluable work, entitled, A Complete System of Astronomy,) he was probably enabled to do by the Chaldean Saros, a period of 223 lunations; after which, the eclipses return again nearly in the same order. Philolaus, a disciple of Pythagoras, lived about four hundred and fifty years before Christ, and is said to have taught the true solar system,—placing the sun in the centre, with the earth and all the planets revolving about it; a system which, it is believed, Pythogaras himself had conceived, and was inclined to adopt.

However, Hipparchus, who lived between one hundred and twenty-five and one hundred and sixty years before the Christian era, and whom Mr. Vince styles “the Father of Astronomy,” was the first person that cultivated every part of that science. His discoveries, together with those of Ptolemy, are preserved in the Μεγαλη Σύνταξις, or Great Construction,—Ptolemy’s celebrated work on Astronomy, named by the Arabs the Almagest, and now usually so called.