Note 10 — Chapter I · THE STRAITS OF GIBRALTAR.

Eratosthenes of Cyrene measured the terrestrial meridian by the problem worked out from the well of Syene. To predict eclipses the mechanism of the heavens must be known. They were predicted by the ancients, e.g. Thales in the seventh century before Christ, Eparcus of Mycea, in the second; Hellico of Cyzycus, and Eudemus. Anaxagoras of Clasomene narrowly escaped death for explaining their cause. Among the Romans, Sulpicius Gallus predicted an eclipse during the war against Perseus; and Drusus, by doing so, quelled an insurrection (Tacit. Annals. I. 28). Pythagoras taught publicly that the earth was a sphere, and the centre of the universe; but he communicated to the initiated its double motion round its axis and the sun. Cicero was the friend of the man who calculated the exact distance of the moon, and approached to that of the sun.