270 HISTORY OF GREECE. x. stationed it close neighborhood of the land-force, in a tortifiec? position at the extremity of the double blockading wall between the southern cliff of Epipolae and the Great Harbor. From such a station in the interior of the harbor, it was difficult for the Athenian triremes to perform the duties incumbent on them, of watching the two ports of Syracuse one on each side of the isthmus which joins Ortygia to the mainland so as to prevent any exit of ships from within, or ingress of ships from without, and of insuring the unobstructed admission by sea of supplies for their own army. For both these purposes, the station of Plem- myrium was far more convenient ; and Nikias now saw that henceforward his operations would be for the most part maritime. Without confessing it openly, he thus practically acknowledged that the superiority of land-force had passed to the side of his opponents, and that a successful prosecution of the blockade had become impossible. 1 Three forts, one of considerable size and two subsidiary, were erected on the sea-board of Cape Plemmyrium, which became the station for triremes as well as for ships of burden. Though the situation was found convenient for all naval operations, it entailed also serious disadvantages ; being destitute of any spring of water, such as the memorable fountain of Arethusa on the opposite island of Ortygia. So that for supplies of water, and of wood also, the crews of the ships had to range a considerable distance, exposed to surprise from the numerous Syracusan cavalry placed in garrison at the temple of Zeus Olympius. Day after day, losses were sustained in this manner, besides the increased facili- ties given for desertion, which soon fatally diminished the efficiency of each ship's crew. As the Athenian hopes of success now de- clined, both the slaves and the numerous foreigners who served in their navy became disposed to steal away. And though the ships of war, down to this time, had been scarcely at all engaged in actual warfare, yet they had been for many months con- tinually at sea and on the watch, without any opportunity of hauling ashore to refit. Hence the naval force, now about to be called into action as the chief hope of the Athenians, was found lamentably degenerated from that ostentatious perfectior
1 Thucyd. vii, 4.
