For the distance between Terêdon or Diridôtis, at the mouth of the Euphrates (which remained separate from that of the Tigris until the first century of the Christian era), to Babylon, see Strabo, ii, p. 80; xvi, p. 739.
It is important to keep in mind the warning given by Ritter, that none of the maps of the course of the river Euphrates, prepared previously to the publication of Colonel Chesney’s expedition in 1836, are to be trusted. That expedition gave the first complete and accurate survey of the course of the river, and led to the detection of many mistakes previously committed by Mannert, Reichard, and other able geographers and chartographers. To the immense mass of information contained in Ritter’s comprehensive and laborious work, is to be added the farther merit, that he is always careful in pointing out where the geographical data are insufficient and fall short of certainty. See West-Asien, B. iii, Abtheilung iii, Abschnitt i, sect. 41, p 959.
[567] Strabo, xiii, p. 617, with the mutilated fragment of Alkæus, which O Müller has so ingeniously corrected (Rhenisch. Museum, i, 4, p. 287).
[568] Strabo, xvi, p. 740.
[569] Diodor. (i. 31) states this point justly with regard to the ancient kings of Egypt—ἔργα μεγάλα καὶ θαυμαστὰ διὰ τὰς πολυχειρίας κατασκευάσαντας, ἀθάνατα τῆς ἑαυτῶν δόξες καταλιπεῖν ὑπομνήματα.
[570] See the description of this desert in Xenoph. Anab. i, 5, 1-8.
[571] The Ten Thousand Greeks passed from the outside to the inside of the wall of Media: it was one hundred feet high, twenty feet wide, and was reported to them as extending twenty parasangs or six hundred stadia (= seventy miles) in length (Xenoph. Anab. ii, 4, 12). Eratosthenês called it τὸ Σεμιράμιδος διατείχισμα (Strabo, ii, p. 80): it was seemingly about twenty-five miles north of Bagdad.
There is some confusion about the wall of Media: Mannert (Geogr. der G. und R. v. 2, p. 280) and Forbiger also (Alte Geogr. sect. 97, p. 616, note 94) appear to have confounded the ditch dug by special order of Artaxerxês to oppose the march of the younger Cyrus, with the Nahar-Malcha or Royal canal between the Tigris and the Euphrates: see Xenoph. Anab. i, 7, 15.
It is singular that Herodotus makes no mention of the wall of Media, though his subject (i, 185) naturally conducts him to it: he seems to have sailed down the Euphrates to Babylon, and must, therefore, have seen it, if it had really extended to the Euphrates, as some authors have imagined. Probably, however, it was not kept up with any care, even in his time, seeing that its original usefulness was at an end, after the whole of Asia, from the Euxine to the Persian gulf, became subject to the Persians.
[572] Strabo, xvi, p. 744.