LEARNING AND RESEARCH 387 murmuring a line from the Phcenomena. The greatest man of learning of the whole Ptolemaic age, Eratos- thenes, kept his geography and chronology, and his works on the Old Comedy, to a prose form. His little epos about the death and avenging of Hesiod, and his elegy Erigone, are on legendary and what we should call ' poetical 'subjects. In Prose, learning and research set the prevailing tone. The marches of Alexander had thrown open an immense stretch of the world to Greek science, and the voyages of his admiral Nearchus, and of men like Polemon and Pytheas, completely altered ancient geography. Our chief handbooks are a Tour of the World and a PeriphU or 'Voyage-round' various coasts, current under the names of Skymnus and Skylax respectively. The scien- tific organisation of geography was carried out by men like Eratosthenes and Hipparchus, involving the inven- tion of systems for calculating latitude and longitude, and the use of trigonometry. Mathematics, pure and applied, were developed by a great number of distinguished men, including Euclid, in the time of Ptolemy I., and Archi- medes, who died in 212. Mechanics — the machines being largely of wood, and the motive power generally water or mere gravitation, though in some cases steam — flourished both for military purposes and for ordinary uses of life. There is a curious passage in the extant works of HfiRO, describing a marionette-machine, which only required setting at the beginning to perform un- aided a four-act tragedy, including a shipwreck and a conflagration. Learning was very especially applied to literature. There were two great libraries in Alexandria — the first by the museum and the palace ; the second, both in age
