I. An ancient grammarian and critic, born in Samothrace, flourished in the 2d century B. C. He was educated at Alexandria in the school of Aristophanes of Byzantium, and founded a critical school, which long flourished at Alexandria, Rome, and elsewhere. Alexandria and Rome alone contained at one time no fewer than 40 celebrated grammarians who had been brought up in his academy. He was the preceptor of Ptolemy Epiphanes and Ptolemy Physcon. In his old age he went to Cyprus, and being afflicted with dropsy, he put an end to his lite by voluntary starvation, in his 72d year. Aristarchus is said to have written 800 commentaries on the text of the great Greek poets; but he devoted his chief labor to Homer, whose present text is based upon that adopted by him. Nothing remains of all his writings save scattered fragments.

II. Of Samos, a Greek astronomer, flourished about 270 B. C. He was one of the first who held that the earth revolves around the sun, for which opinion some thought him guilty of impiety. The only work of his extant is a treatise on the distance and magnitude of the sun and moon, of which the original was published by Wallis in 1688, and a French translation in 1810.