the argument [of Hipparchus] is overturned. We have stated before, that supposing two lines drawn from the Caspian Gates, one to Thapsacus, and the other to the mountains of Armenia opposite Thapsacus, and distant therefrom, according to Hipparchus’s own estimate, 2100 stadia at the very least, neither of them would be parallel to each other, nor yet to that line which, passing through Babylon, is styled by Eratosthenes the southern side [of the third section]. As he could not inform us of the exact length of the route by the mountains, Eratosthenes tells us the distance between Thapsacus and the Caspian Gates; in fact, to speak in a general way, he puts this distance in place of the other; besides, as he merely wanted to give the length of the territory between Ariana and the Euphrates, he was not particular to have the exact measure of either route. To pretend that he considered the lines to be parallel to each other, is evidently to accuse the man of more than childish ignorance, and we dismiss the insinuation as nonsense forthwith.
30. There, however, are some instances in which one may justly accuse Eratosthenes. There is a difference in dissecting limb by limb, or merely cutting off portions [indiscriminately], (for in the former you may only separate parts having a natural outline, and distinguished by a regular form; this the poet alludes to in the expression,
“Cutting them limb from limb;”571
whereas in regard to the latter this is not the case,) and we may adopt with propriety either one or other of these plans according to the time and necessity. So in Geography, if you enter into every detail, you may sometimes be compelled to divide your territories into portions, so to speak, but it is a more preferable way to separate them into limbs, than into such chance pieces; for thus only you can define accurately particular points and boundaries, a thing so necessary to the geographer. When it can be done, the best way to define a country is by the rivers, mountains, or sea; also, where possible, by the nation or nations [who inhabit it], and by its size and configuration. However, in default of a geometrical definition, a simple and general description may be said always to answer the purpose. In regard to size, it is sufficient to state the greatest length and breadth; for example, that the habitable earth is 70,000 stadia long, and that its breadth is scarcely half its length.572 And as to form, to compare a country to any geometrical or other well-known figure. For example, Sicily to a triangle, Spain to an ox-hide, or the Peloponnesus to a plane-leaf.573 The larger the territory to be divided, the more general also ought its divisions to be.
31. [In the system of Eratosthenes], the habitable earth has been admirably divided into two parts by the Taurus and the Mediterranean Sea, which reaches to the Pillars. On the southern side, the limits of India have been described by a variety of methods; by its mountains,574 its river,575 its seas,576 and its name,577 which seems to indicate that it is inhabited only by one people.578 It is with justice too that he attributes to it the form of a quadrilateral or rhomboid. Ariana is not so accurately described, on account of its western side being interwoven with the adjacent land. Still it is pretty well distinguished by its three other sides, which are formed by three nearly straight lines, and also by its name, which shows it to be only one nation.579 As to the Third Section of Eratosthenes, it cannot be considered to be defined or circumscribed at all; for that side of it which is common to Ariana is but ill defined, as before remarked. The southern side, too, is most negligently taken: it is, in fact, no boundary to the section at all, for it passes right through its centre, leaving entirely outside of it many of the southern portions. Nor yet does it represent the greatest length of the section, for the northern side is the longest.580 Nor, lastly, can the Euphrates be its western boundary, not even if it flowed in a right line, since its two extremes581 do not lie under the same meridian. How then is it the western rather than the southern boundary? Apart from this, the distance to the Seas of Cilicia and Syria is so inconsiderable, that there can be no reason why he should not have enlarged the third section, so as to include the kingdoms of Semiramis and Ninus, who are both of them known as Syrian monarchs; the first built Babylon, which he made his royal residence; the second Ninus,582 the capital of Syria;583 and the same dialect still exists on both sides of the Euphrates. The idea of thus dismembering so renowned a nation, and allotting its portions to strange nations with which it had no connexion, is as peculiarly unfortunate. Eratosthenes cannot plead that he was compelled to do this on account of its size, for had it extended as far as the sea and the frontiers of Arabia Felix and Egypt, even then it would not have been as large as India, or even Ariana. It would have therefore been much better to have enlarged the third section, making it comprehend the whole space as far as the Sea of Syria; but if this were done, the southern side would not be as he represents it, nor yet in a straight line, but starting from Carmania would follow the right side of the sea-shore from the Persian Gulf to the mouth of the Euphrates; it would then approach the limits of Mesene584 and Babylon, where the Isthmus commences which separates Arabia Felix from the rest of the continent. Traversing the Isthmus, it would continue its course to the recess of the Arabian Gulf and Pelusium,585 thence to the mouth of the Nile at Canopus.586 Such would be the southern side. The west would be traced by the sea-shore from the [river’s] mouth at Canopus to Cilicia.587
32. The fourth section would consist of Arabia Felix, the Arabian Gulf, and the whole of Egypt and Ethiopia. Its length bounded by two meridians, one drawn through its most western point, the other through its most eastern; and its breadth by two parallels through its most northern and southern points. For this is the best way to describe the extent of irregular figures, whose length and breadth cannot be determined by their sides.
In general it is to be observed, that length and breadth are to be understood in different ways, according as you speak of the whole or a part. Of a whole, the greater distance is called its length, and the lesser its breadth; of a part, that is to be considered the length which is parallel to the length of the whole, without any regard whether it, or that which is left for the breadth, be the greater distance. The length of the whole habitable earth is measured from east to west by a line drawn parallel to the equator, and its breadth from north to south in the direction of the meridian; consequently, the length of any of the parts ought to be portions of a line drawn parallel to the length of the whole, and their breadth to the breadth of the whole. For, in the first place, by this means the size of the whole habitable earth will be best described; and secondly, the disposition and configuration of its parts, and the manner in which one may be said to be greater or less than another, will be made manifest by thus comparing them.
33. Eratosthenes, however, measures the length of the habitable earth by a line which he considers straight, drawn from the Pillars of Hercules, in the direction of the Caspian Gates and the Caucasus. The length of the third section, by a line drawn from the Caspian Gates to Thapsacus, and of the fourth, by one running from Thapsacus through Heroopolis to the country surrounded by the Nile: this must necessarily be deflected to Canopus and Alexandria, for there is the last mouth of the Nile, which goes by the name of the Canopic588 or Heracleotic mouth. Whether therefore these two lengths be considered to form one straight line, or to make an angle with Thapsacus, certain it is that neither of them is parallel to the length of the habitable earth; this is evident from what Eratosthenes has himself said concerning them. According to him the length of the habitable earth is described by a right line running through the Taurus to the Pillars of Hercules, in the direction of the Caucasus, Rhodes, and Athens. From Rhodes to Alexandria, following the meridian of the two cities, he says there cannot be much less than 4000 stadia,