The most intelligent modern investigators and travellers,—Major Rennell, Mr. Ainsworth, Mr. Hamilton, Colonel Chesney, Professor Koch, etc., offer no satisfactory solution of the difficulty. Major Rennell reckons the parasangs as equal to 2.25 geogr. miles; Mr. Ainsworth at three geogr. miles; Mr. Hamilton (travels in Asia Minor, c. 42, p. 200), at something less than two and a half geogr. miles; Colonel Chesney (Euphrat. and Tigris, ch. 8, p. 207) at 2.608 geogr. miles between Sardis and Thapsakus—at 1.98 geogr. miles, between Thapsakus and Kunaxa,—at something less than this, without specifying how much, during the retreat. It is evident that there is no certain basis to proceed upon, even for the earlier portion of the route; much more, for the retreat. The distance between Ikonium and Dana (or Tyana), is one of the quantities on which Mr. Hamilton rests his calculation; but we are by no means certain that Cyrus took the direct route of march; he rather seems to have turned out of his way, partly to plunder Lykaonia, partly to conduct the Kilikian princess homeward. The other item, insisted upon by Mr. Hamilton, is the distance between Kelænæ and Kolossæ, two places the site of which seems well ascertained, and which are by the best modern maps, fifty-two geographical miles apart. Xenophon calls the distance twenty parasangs. Assuming the road by which he marched to have been the same with that now travelled, it would make the parasang of Xenophon = 2.6 geographical miles. I have before remarked that the road between Kolossæ and Kelænæ was probably measured and numbered according to parasangs; so that Xenophon, in giving the number of parasangs between these two places, would be speaking upon official authority. Even a century and a half afterwards, the geographer Eratosthenes found it not possible to obtain accurate measurements, in much of the country traversed by Cyrus (Strabo, ii, p. 73.) Colonel Chesney remarks,—“From Sardis to Cunaxa, or the mounds of Mohammed, cannot be much under or over twelve hundred and sixty-five geographical miles; making 2.364 geographical miles for each of the five hundred and thirty-five parasangs given by Xenophon between those two places.”