The ostracism of Thucydidês apparently took place about two years[34] after the conclusion of the thirty years’ truce,—443-442 B.C.,—and it is to the period immediately following that the great Periklêan works belong. The southern wall of the acropolis had been built out of the spoils brought by Kimon from his Persian expeditions; but the third of the long walls connecting Athens with the harbor was the proposition of Periklês, at what precise time we do not know. The long walls originally completed—not long after the battle of Tanagra, as has already been stated—were two, one from Athens to Peiræus, another from Athens to Phalêrum: the space between them was broad, and if in the hands of an enemy, the communication with Peiræus would be interrupted. Accordingly, Periklês now induced the people to construct a third or intermediate wall, running parallel with the first wall to Peiræus, and within a short distance[35]—seemingly near one furlong—from it: so that the communication between the city and the port was placed beyond all possible interruption, even assuming an enemy to have got within the Phaleric wall. It was seemingly about this time, too, that the splendid docks and arsenal in Peiræus, alleged by Isokratês to have cost one thousand talents, were constructed:[36] while the town itself of Peiræus was laid out anew with straight streets intersecting at right angles. Apparently, this was something new in Greece,—the towns generally, and Athens itself in particular, having been built without any symmetry, or width, or continuity of streets:[37] and Hippodamus the Milesian, a man of considerable attainments in the physical philosophy of the age, derived much renown as the earliest town architect, for having laid out the Peiræus on a regular plan. The market-place, or one of them at least, permanently bore his name,—the Hippodamian agora.[38] At a time when so many great architects were displaying their genius in the construction of temples, we are not surprised to hear that the structure of towns began to be regularized also: moreover, we are told that the new colonial town of Thurii, to which Hippodamus went as a settler, was also constructed in the same systematic form as to straight and wide streets.[39] [34] Plutarch, Periklês, c. 16: the indication of time, however, is vague. [35] Plato, Gorgias, p. 455, with Scholia; Plutarch, Periklês, c. 13: Forchhammer, Topographie von Athen, in Kieler Philologische Studien, pp. 279-282. [36] Isokratês, Orat. vii: Areopagit. p. 153. c. 27. [37] See Dikæarchus, Vit. Græciæ, Fragm. ed. Fuhr. p. 140: compare the description of Platæa in Thucydidês, ii, 3. All the older towns now existing in the Grecian islands are put together in this same manner,—narrow, muddy, crooked ways,—few regular continuous lines of houses: see Ross, Reisen in den Griechischen Inseln, Letter xxvii, vol. ii, p. 20.