Hipparchus, who flourished about the middle of the second century B.C., was, through his careful observations, the real founder of scientific astronomy. He calculated eclipses, catalogued the stars, and wrote several astronomical works of a really scientific character.
Claudius Ptolemy lived in Egypt about the middle of the second century after Christ. His great reputation is due not so much to his superior genius as to the fortunate circumstance that a vast work compiled by him, preserved and transmitted to later times almost all the knowledge of the ancients on astronomical and geographical subjects. In this way it has happened that his name has become attached to various doctrines and views respecting the universe, though these probably were not originated by him. The phrase Ptolemaic system, however, links his name inseparably with that conception of the solar system set forth in his works, which continued to be the received theory from his time until Copernicus—fourteen centuries later.
Ptolemy combated the theory of Aristarchus in regard to the rotation and revolution of the earth; yet he believed the earth to be a globe, and supported this view by exactly the same arguments that we to-day use to prove the doctrine.
