Aristarchus

Aristarchus (1) OF SAMOS, a celebrated ancient astronomer, of the Alexandrian school, who flourished 280-264 B.C. He seems certainly to have anticipated Copernicus, maintaining that the earth moves round the sun. For this we have the testimony of Archimedes: he was even accused of impiety on this account. All his writings have perished, excepting a short essay on the sizes and distances of the sun and the moon (ed. by Wallis, Oxford, 1688). In this he shows the method of estimating the relative distances of the sun and the moon from the earth, by the angle formed by the two bodies at the observer's eye at that moment when the moon is exactly half-luminous. The principle was accurate in theory; but the angle to be measured was too small, and the available instruments too imperfect to give accurate results.—(2) OF SAMOTHRACE, a very famous grammarian and critic, who flourished about 160 B.C. in Alexandria, where he educated the children of Ptolemy Philopator, and superintended the great library. His life was chiefly devoted to the elucidation and restoration of the text of the Greek poets—Pindar, the tragedians, and others, but especially Homer. The form in which we now have the Homeric poems preserved is in great measure owing to his judgment and industry. The strictness of his critical principles has made his name a proverbial expression for a severely just and judicious critic. He is said to have written 800 treatises, and founded a school of critics, some of whom have preserved fragments of his works. To escape the tyranny of his old pupil, Ptolemy VII. Physkon, he fled to Cyprus, where he died at the age of 72, of voluntary starvation on account of an incurable dropsy. See Ludwig's Aristarchi Homerische Teatkritik (Leip. 1884).