HOW THE LONG WALLS WENT DOWN. 215 Yet for nine years more the war continued, with much the same succession of varying events as before. But during this period Sparta was learning an important lesson. If she would defeat Athens, she must learn how to win victories on sea as well as on land. After every defeat of a fleet she built and equipped another, and gradually grew stronger in ships, and her seamen more skilful and expert, until the old difference between Athenian and Spartan seamen ceased to exist. Persia also came to the aid of Sparta, supplied her with money, and enabled her to replace her lost ships with ever new ones, while the ship-building power of Athens declined. In 405 z.c. the crisis came. Athens was forced to depend solely for subsistence on her fleet. That gone, all would be gone. In the autumn of that year she had a fleet of one hundred and eighty triremes in the Hellespont, in the close vicinity of a Spartan ficet of about the same force, under an able admiral named Lysander. A gospotami, or Goat’s River (a name of fatal sound to all later Athenians), was the station of the Athenian fleet. That of Sparta lay opposite, across the strait, nearly two miles away. And now an interesting scene began. Every day the Athenian fleet crossed the strait and offered battle to the Spartans, daring them to come out from their sheltered position. And every day, when the Spartans had refused, it would go back to the opposite shore, where many of the men were per- mitted to land. Day by day this challenge was re- peated, the Athenians growing daily more confident