Erasinidês and his division lent their hands to the execution of a work which completed the scheme of defence for the city. Gylippus took the precaution of constructing a fort or redoubt on the high ground of Epipolæ, so as to command the approach to Syracuse from the high ground of Euryalus; a step which Hermokratês had not thought of until too late, and which Nikias had never thought of at all, during his period of triumph and mastery. He erected a new fort on a suitable point of the high ground, backed by three fortified positions or encampments at proper distances in the rear of it, intended for bodies of troops to support the advanced post in case it was attacked. A continuous wall was then carried from this advanced post down the slope of Epipolæ, so as to reach and join the counter-wall recently constructed; whereby this counter-wall, already traversing and cutting the Athenian line of circumvallation, became in fact prolonged up the whole slope of Epipolæ, and barred all direct access from the Athenians in their existing lines up to the summit of that eminence, as well as up to the northern cliff. The Syracusans had now one continuous and uninterrupted line of defence; a long single wall, resting at one extremity on the new-built fort upon the high ground of Epipolæ, at the other extremity, upon the city wall. This wall was only single; but it was defended, along its whole length, by the permanent detachments occupying the three several fortified positions or encampments just mentioned. One of these positions was occupied by native Syracusans; a second, by Sicilian Greeks; a third, by other allies. Such was the improved and systematic scheme of defence which the genius of Gylippus first projected, and which he brought to execution at the present moment:[400] a scheme, the full value of which will be appreciated when we come to describe the proceedings of the second Athenian armament under Demosthenês. [400] Thucyd. vii, 7. Μετὰ δὲ τοῦτο, αἵ τε τῶν Κορινθίων νῆες καὶ Ἀμπρακιωτῶν καὶ Λευκαδίων ἐσέπλευσαν αἱ ὑπόλοιποι δώδεκα (ἦρχε δὲ αὐτῶν Ἐρασινίδης Κορίνθιος), καὶ ~ξυνετείχισαν τὸ λοιπὸν τοῖς Συρακοσίοις μέχρι τοῦ ἐγκαρσίου τείχους~. These words of Thucydidês are very obscure, and have been explained by different commentators in different ways. The explanation which I here give does not, so far as I know, coincide with any of them; yet I venture to think that it is the most plausible, and the only one satisfactory. Compare the Memoir of Dr. Arnold on his Map of Syracuse (Arn. Thucyd. vol. iii, p. 273), and the notes of Poppo and Göller. Dr. Arnold is indeed so little satisfied with any explanation which had suggested itself to him that he thinks some words must have dropped out.