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. CHAPTER XXI. SOCIAL LIFE OF THE GREEKS. EDUCATION.--Education at Sparta, where it was chiefly gymnastic, as we have seen (p. 115), was a state affair; but at Athens and throughout Greece generally, the youth were trained in private schools. These schools were of all grades, ranging from those kept by the most obscure teachers, who gathered their pupils in some recess of the street, to those established in the Athenian Academy and Lyceum by such philosophers as Plato and Aristotle. [Illustration: A GREEK SCHOOL. (After a vase-painting.)] It was only the boys who received education. These Grecian boys, Professor Mahaffy imagines, were "the most attractive the world has ever seen." At all events, we may believe that they were trained more carefully and delicately than the youth among any other people before or since the days of Hellenic culture. In the nursery, the boy was taught the beautiful myths and stories of the national mythology. At about seven he entered school, being led to and from the place of training by an old slave, who bore the name of _pedagogue_, which in Greek means a guide or leader of boys--not a teacher. His studies were grammar, music, and gymnastics, the aim of the course being to secure a symmetrical development of mind and body alike. Grammar included reading, writing, and arithmetic; music, which embraced a wide range of mental accomplishments, trained the boy to appreciate the masterpieces of the great poets, to contribute his part to the musical diversions of private entertainments, and to join in the sacred choruses and in the pæan of the battlefield. The exercises of the palestræ and the gymnasia trained him for the Olympic contests, or for those sterner hand- to-hand battle-struggles, in which so much depended upon personal strength and dexterity.