The Greek astronomer Aristarchus of Samos was active in the third century BCE, more than a thousand years before Copernicus presented his model of a heliocentric solar system. It was Aristarchus, however, who first suggested - in a work that is now lost - that the planets revolve around the sun. Edited by Sir Thomas Little Heath (1861–1940), this 1913 publication contains the ancient astronomer's only surviving treatise, which does not propound the heliocentric hypothesis. The Greek text is based principally on the tenth-century manuscript Vaticanus Graecus 204. Heath also provides a facing-page English translation and explanatory notes. The treatise is prefaced by a substantial history of ancient Greek astronomy, ranging from Homer's first mention of constellations to work by Heraclides of Pontus in the fourth century BCE relating to the Earth's rotation. Heath's collection of translated ancient texts, Greek Astronomy (1932), is also reissued in this series.