ἐναντίωμα—only here in Thuc.: Dem. de Cor. 328, παρὰ τῆς τύχης τι συμβέβηκεν ἐναντίωμα. περιετείχιζον—imp., =began the circumvallation.

σίδηρος—according to the scholiast the same as σιδηρια λιθουργά, ch. 4, 6.

ἀρξάμενοι δ᾽—the construction of this sentence is loose and irregular; the chief difficulty being with what verb ἀρξάμενοι and the following participles are to be connected. Krüger and Arnold refer them to the preceding περιετείχιζον: but the δέ with ἀρξάμενοι is against this view, and marks the beginning of a new sentence. Accordingly Poppo connects all the participles with ἀπεσταύρουν in line 14. This verb however does not contain the main idea of the sentence, but only describes a small part of the siege operations. There remains therefore the explanation suggested in Classen's critical note, that some general word such as περιετείχιζον was intended to follow ἀρξάμενοι, and must be understood with ὶπ᾽ έκείνου...Νισαίας and what follows. A similar view is taken by Jowett.

ἀπὸ τοῦ τείχους—the long walls and the space enclosed, which had been taken at daybreak (ch. 66). For sing. τείχους cf. ch. 67, 19: also ii. 13, where τοῦ μακροῦ means the double wall to the Piraeus. διοικοδομήσαντες—‘walling off’, by a cross work, to prevent interruption from the city: cf. viii. 90, διῳκοδόμησαν στοάν: so in iii. 34 and vii. 60 διατείχισμα means a separate space walled off, a separate fortified work.

ἀπ᾽ ἐκείνου ἑκατέρωθεν—the Athenians extended their works on both sides, so as to enclose Nisaea from sea to sea. ἐς θάλασσαν—sc. περιετείχιζον, note on line 9. Νισαίας— dep. on ἑκατέρωθεν: ch. 31, 5, τῆς νήσου ἑκατέρωθεν.

τάφρον...διελομένη—the sentence, which began with οἱ στρατηγοί, has now expanded its subject, and applies to the whole Athenian force, with which the collective στρατιά stands in apposition. For διελομένη see note on ch. 11, 11: so v. 75, διελόμενοι τὴν πόλιν περιετείχιζον.

προαστείου—‘an open space like the parks in London. partly planted with trees, and containing public walks, colonnades, temples, and the houses of some of the principal citizens. It was used as a ground for reviews of the army, and for public games’ (Arnold).

καὶ κόπτοντες—most editors take this as a fresh sentence. Probably however as no finite verb has yet been expressed, though intended, the main sentence closes with ἀπεσταύρουν, although in sense this verb applies to the final clause alone. The clue has in fact been dropped in a maze of participles and parentheses. According to this view the καί which precedes κόπτοντες corresponds to the τε which follows ἐκ in the previous line; otherwise διελομένη and χρώμενοι are connected by (τάφρον) τε...（ἔκ) τε.

τἀ δένδρα—esp. the fruit trees, which would be found in the προάστειον, mainly olives and figs: see Arnold on ii. 75. ὕλην—‘brushwood’, for fascines and to interlace with the palisades. See the account of the siege of Plataeae, ii. 75, 76; where we find that ξύλα is the word used for timber from forest trees, as in ch. 13, 3 and 52, 16: cf. Xen. Anab. i. 5, 1, εἰ δέ τι καὶ ἄλλο ἐνῆν ὕλης ἢ καλάμου (shrub or plant)...δένδρον δ᾽ οὐδὲν ἐνῆν.

εἴ πῃ δέοιτό τι—‘if at any point any part needed it’; τι being the subject of the verb; so Poppo. Krüger proposes to read δέοι, as in ch. 4, 9, εἴ που δέοι. Classen and Jowett take δέοιτο=δέοι, citing Soph. O. C. 570, ὤστε βραχέα μοι δεῖσθαι φράσαι: Dem. de Cor. 276, οὐδὲν...εἰσήγετο ὦν ἐδεῖτ᾽ αὐτῷ. Veitch gives Plat. Meno 79 c, and Hdt. iv. 11, as instances in which δεῖσθαι and δεόμενον ‘may be thought to have rather an appearance of impersonality’. All these passages however can be explained without depriving δέομαι of its usual meaning.

ἐπάλξεις λαμβάνουσαι—‘with the addition of battlements’: ch. 115, 3, ἀπ᾽ οἰκιῶν ἐπάλξεις ἐχουσῶν. In the same ch., line 14, we have λαβὸν μεῖζον ἄχθος: cf. Hdt. ix. 7, τὸ τεῖχος ...ἤδη ἐπάλξεις ἐλάμβανε. αὐταὶ ὑπῆρχον—‘of themselves’, cf. ch. 4, 15.

ὅσον οὐκ—‘all but’: i. 36, ὅσον οὑ παρόντα πόλεμον: ch. 125, 11, ὅσον οὔπω. σίτου τε—the first reason for their surrender; two others are then given with νομίζοντες and ἠγούμενοι.

ἕκαστον...παραδόντας—acc. because the subject of ἀπολυθῆναι is not identical with the subject of ξυνέβησαν, but corresponds to ἕκαστον put collectively. The convention was made by the Lacedaemonian officers on behalf of the whole force. ‘The ἄρχων here spoken of was the Spartan commander of the Peloponnesian garrison, like Tantalus at Thyrea, ch. 57; Pasitelidas at Torone, v. 3; Menedaeus and his colleagues in Acarnania, iii. 100’ (Arnold).

χρῆσθαι—so ii. 4, ξυνέβησαν παραδοῦναι σφᾶς αὐτοὺς... χρήσασθαι ὅ τι ἂν βούλωνται. ἀπορρήξαντες—by destroying a portion of the walls; thus securing their occupation of Nisaea, and the rest of the walls.

παραλαβόντες—ch. 54, 21.