But though Athens was thus exempted from all fear of aggression on the side of Eubœa, the consequences of this departure of the fleet were such as to demonstrate how irreparably the island itself had passed out of her supremacy. The inhabitants of Chalkis and the other cities, now left without foreign defence against her, employed themselves jointly with the Bœotians, whose interest in the case was even stronger than their own, in divesting Eubœa of its insular character, by constructing a mole or bridge across the Euripus, the narrowest portion of the Eubœan strait, where Chalkis was divided from Bœotia. From each coast a mole was thrown out, each mole guarded at the extremity by a tower, and leaving only an intermediate opening, broad enough for a single vessel to pass through, covered by a wooden bridge. It was in vain that the Athenian Theramenês, with thirty triremes, presented himself to obstruct the progress of this undertaking. The Eubœans and Bœotians both prosecuted it in such numbers, and with so much zeal, that it was speedily brought to completion. Eubœa, so lately the most important island attached to Athens, is from henceforward a portion of the mainland, altogether independent of her, even though it should please fortune to reëstablish her maritime power.[152] [152] Diodor. xiii, 47. He places this event a year later, but I agree with Sievers in conceiving it as following with little delay on the withdrawal of the protecting fleet (Sievers, Comment. in Xenoph. Hellen. p. 9; note, p. 66). See Colonel Leake’s Travels in Northern Greece, for a description of the Euripus, and the adjoining ground, with a plan, vol. ii, ch. xiv, pp. 259-265. I cannot make out from Colonel Leake what is the exact breadth of the channel. Strabo talks in his time of a bridge reaching two hundred feet (x, p. 400). But there must have been material alterations made by the inhabitants of Chalkis during the time of Alexander the Great (Strabo, x, p. 447). The bridge here described by Diodorus, covering an open space broad enough for one ship, could scarcely have been more than twenty feet broad; for it was not at all designed to render the passage easy. The ancient ships could all lower their masts. I cannot but think that Colonel Leake (p. 259) must have read, in Diodorus, xiii, 47, οὐ in place of ὁ.