Chapter I (2)

35. These arguments may be very geometrical, but they are not convincing. After having himself invented these various difficulties, he dismisses them, saying, “Had [Eratosthenes] been chargeable for small distances only, he might have been excused; but since his mistakes involve thousands of stadia, we cannot pardon him, more especially since he has laid it down that at a mere distance of 400 stadia,[595] such as that between the parallels of Athens and Rhodes, there is a sensible variation [of latitude].” But these sensible variations are not all of the same kind, the distance [involved therein] being in some instances greater, in others less; greater, when for our estimate of the climata we trust merely to the eye, or are guided by the vegetable productions and the temperature of the air; less, when we employ gnomons and dioptric instruments. Nothing is more likely than that if you measure the parallel of Athens, or that of Rhodes and Caria, by means of a gnomon, the difference resulting from so many stadia[596] will be sensible. But when a geographer, in order to trace a line from west to east, 3000 stadia broad, makes use of a chain of mountains 40,000 stadia long, and also of a sea which extends still farther 30,000 stadia, and farther wishing to point out the situation of the different parts of the habitable earth relative to this line, calls some southern, others northern, and finally lays out what he calls the sections, each section consisting of divers countries, then we ought carefully to examine in what acceptation he uses his terms; in what sense he says that such a side [of any section] is the north side, and what other is the south, or east, or west side. If he does not take pains to avoid great errors, he deserves to be blamed, but should he be guilty merely of trifling inaccuracies, he should be forgiven. But here nothing shows thoroughly that Eratosthenes has committed either serious or slight errors, for on one hand what he may have said concerning such great distances, can never be verified by a geometrical test, and on the other, his accuser, while endeavouring to reason like a geometrician, does not found his arguments on any real data, but on gratuitous suppositions.

36. The fourth section Hipparchus certainly manages better, though he still maintains the same censorious tone, and obstinacy in sticking to his first hypotheses, or others similar. He properly objects to Eratosthenes giving as the length of this section a line drawn from Thapsacus to Egypt, as being similar to the case of a man who should tell us that the diagonal of a parallelogram was its length. For Thapsacus and the coasts of Egypt are by no means under the same parallel of latitude, but under parallels considerably distant from each other,[597] and a line drawn from Thapsacus to Egypt would lie in a kind of diagonal or oblique direction between them. But he is wrong when he expresses his surprise that Eratosthenes should dare to state the distance between Pelusium and Thapsacus at 6000 stadia, when he says there are above 8000. In proof of this he advances that the parallel of Pelusium is south of that of Babylon by more than 2500 stadia, and that according to Eratosthenes (as he supposes) the latitude of Thapsacus is above 4800 stadia north of that of Babylon; from which Hipparchus tells us it results that [between Thapsacus and Pelusium] there are more than 8000 stadia. But I would inquire how he can prove that Eratosthenes supposed so great a distance between the parallels of Babylon and Thapsacus? He says, indeed, that such is the distance from Thapsacus to Babylon, but not that there is this distance between their parallels, nor yet that Thapsacus and Babylon are under the same meridian. So much the contrary, that Hipparchus has himself pointed out, that, according to Eratosthenes, Babylon ought to be east of Thapsacus more than 2000 stadia. We have before cited the statement of Eratosthenes, that Mesopotamia and Babylon are encircled by the Tigris and Euphrates, and that the greater portion of the Circle is formed by this latter river, which flowing north and south takes a turn to the east, and then, returning to a southerly direction, discharges itself [into the sea]. So long as it flows from north to south, it may be said to follow a southerly direction; but the turning towards the east and Babylon is a decided deviation from the southerly direction, and it never recovers a straight course, but forms the circuit we have mentioned above. When he tells us that the journey from Babylon to Thapsacus is 4800 stadia, he adds, following the course of the Euphrates, as if on purpose lest any one should understand such to be the distance in a direct line, or between the two parallels. If this be not granted, it is altogether a vain attempt to show that if a right-angled triangle were constructed by lines drawn from Pelusium and Thapsacus to the point where the parallel of Thapsacus intercepts the meridian of Pelusium, that one of the lines which form the right angle, and is in the direction of the meridian, would be longer than that forming the hypotenuse drawn from Thapsacus to Pelusium.[598] Worthless, too, is the argument in connexion with this, being the inference from a proposition not admitted; for Eratosthenes never asserts that from Babylon to the meridian of the Caspian Gates is a distance of 4800 stadia. We have shown that Hipparchus deduces this from data not admitted by Eratosthenes; but desirous to controvert every thing advanced by that writer, he assumes that from Babylon to the line drawn from the Caspian Gates to the mountains of Carmania, according to Eratosthenes’ description, there are above 9000 stadia, and from thence draws his conclusions.

37. Eratosthenes[599] cannot, therefore, be found fault with on these grounds; what may be objected against him is as follows. When you wish to give a general outline of size and configuration, you should devise for yourself some rule which may be adhered to more or less. After having laid down that the breadth of the space occupied by the mountains which run in a direction due east, as well as by the sea which reaches to the Pillars of Hercules, is 3000 stadia, would you pretend to estimate different lines, which you may draw within the breadth of that space, as one and the same line? We should be more willing to grant you the power of doing so with respect to the lines which run parallel to that space than with those which fall upon it; and among these latter, rather with respect to those which fall within it than to those which extend without it; and also rather for those which, in regard to the shortness of their extent, would not pass out of the said space than for those which would. And again, rather for lines of some considerable length than for any thing very short, for the inequality of lengths is less perceptible in great extents than the difference of configuration. For example, if you give 3000 stadia for the breadth at the Taurus, as well as for the sea which extends to the Pillars of Hercules, you will form a parallelogram entirely enclosing both the mountains of the Taurus and the sea; if you divide it in its length into several other parallelograms, and draw first the diagonal of the great parallelogram, and next that of each smaller parallelogram, surely the diagonal of the great parallelogram will be regarded as a line more nearly parallel and equal to the side forming the length of that figure than the diagonal of any of the smaller parallelograms: and the more your lesser parallelograms should be multiplied, the more will this become evident. Certainly, it is in great figures that the obliquity of the diagonal and its difference from the side forming the length are the less perceptible, so that you would have but little scruple in taking the diagonal as the length of the figure. But if you draw the diagonal more inclined, so that it falls beyond both sides, or at least beyond one of the sides, then will this no longer be the case; and this is the sense in which we have observed, that when you attempted to draw even in a very general way the extents of the figures, you ought to adopt some rule. But Eratosthenes takes a line from the Caspian Gates along the mountains, running as it were in the same parallel as far as the Pillars, and then a second line, starting directly from the mountains to touch Thapsacus; and again a third line from Thapsacus to the frontiers of Egypt, occupying so great a breadth. If then in proceeding you give the length of the two last lines [taken together] as the measure of the length of the district, you will appear to measure the length of one of your parallelograms by its diagonal. And if, farther, this diagonal should consist of a broken line, as that would be which stretches from the Caspian Gates to the embouchure of the Nile, passing by Thapsacus, your error will appear much greater. This is the sum of what may be alleged against Eratosthenes.

38. In another respect also we have to complain of Hipparchus, because, as he had given a category of the statements of Eratosthenes, he ought to have corrected his mistakes, in the same way that we have done; but whenever he has any thing particular to remark, he tells us to follow the ancient charts, which, to say the least, need correction infinitely more than the map of Eratosthenes.

The argument which follows is equally objectionable, being founded on the consequences of a proposition which, as we have shown, is inadmissible, namely, that Babylon was not more than 1000 stadia east of Thapsacus; when it was quite clear, from Eratosthenes’ own words, that Babylon was above 2400 stadia east of that place; since from Thapsacus to the passage of the Euphrates where it was crossed by Alexander, the shortest route is 2400 stadia, and the Tigris and Euphrates, having encompassed Mesopotamia, flow towards the east, and afterwards take a southerly direction and approach nearer to each other and to Babylon at the same time: nothing appears absurd in this statement of Eratosthenes.

39. The next objection of Hipparchus is likewise false. He attempts to prove that Eratosthenes, in his statement that the route from Thapsacus to the Caspian Gates is 10,000 stadia, gives this as the distance taken in a straight line; such not being the case, as in that instance the distance would be much shorter. His mode of reasoning is after this fashion. He says, “According to Eratosthenes, the mouth of the Nile at Canopus,[600] and the Cyaneæ,[601] are under the same meridian, which is distant from that of Thapsacus 6300 stadia. Now from the Cyaneæ to Mount Caspius, which is situated close to the defile[602] leading from Colchis to the Caspian Sea, there are 6600 stadia,[603] so that, with the exception of about 300 stadia, the distance from the meridian of the Cyaneæ to that of Thapsacus, or to that of Mount Caspius, is the same: and both Thapsacus and Mount Caspius are, so to speak, under the same meridian.[604] It follows from this that the Caspian Gates are about equi-distant between Thapsacus and Mount Caspius, but that the distance between them and Thapsacus is much less than the 10,000 stadia mentioned by Eratosthenes. Consequently, as the distance in a right line is much less than 10,000 stadia, this route, which he considered to be in a straight course from the Caspian Gates to Thapsacus, must have been a circumbendibus.”

To this we reply, that Eratosthenes, as is usual in Geography, speaks of right lines, meridians, and parallels to the equator, with considerable latitude, whereas Hipparchus criticizes him with geometrical nicety, as if every line had been measured with rule and compass. Hipparchus at the same time himself frequently deciding as to right lines and parallels, not by actual measurement, but mere conjecture. Such is the first error of this writer. A second is, that he never lays down the distances as Eratosthenes has given them, nor yet reasons on the data furnished by that writer, but from mere assumptions of his own coinage. Thus, where Eratosthenes states that the distance from the mouth of the [Thracian Bosphorus] to the Phasis is 8000 stadia, from thence to Dioscurias 600 stadia,[605] and from Dioscurias to Caspius five days’ journey, (which Hipparchus estimates at 1000 stadia,) the sum of these, as stated by Eratosthenes, would amount to 9600 stadia. This Hipparchus abridges in the following manner. From the Cyaneæ to the Phasis are 5600 stadia, and from the Phasis to the Caspius 1000 more.[606] Therefore it is no statement of Eratosthenes that the Caspius and Thapsacus are under the same meridian, but of Hipparchus himself. However, supposing Eratosthenes says so, does it follow that the distance from the Caspius to the Caspian Gates, and that from Thapsacus to the same point, are equal.[607]

40. In the second book of his Commentaries, Hipparchus, having again mooted the question concerning the mountains of the Taurus, of which we have spoken sufficiently, proceeds with the northern parts of the habitable earth. He then notices the statement of Eratosthenes concerning the countries situated west of the Euxine,[608] namely, that the three [principal] headlands [of this continent], the first the Peloponnesian, the second the Italian, the third the Ligurian, run from north [to south], enclosing the Adriatic and Tyrrhenian Gulfs.[609] After this general exposition, Hipparchus proceeds to criticise each point in detail, but rather on geometrical than geographical grounds; on these subjects, however, the number of Eratosthenes’ errors is so overwhelming, as also of Timosthenes the author of the Treatise on the Ports, (whom Eratosthenes prefers above every other writer, though he often decides even against him,) that it does not seem to be worth my time to review their faulty productions, nor even what Hipparchus has to say about them; since he neither enumerates all their blunders, nor yet sets them right, but only points out how they falsify and contradict each other. Still any one might certainly object to the saying of Eratosthenes, that Europe has but three headlands, and considering as one that which terminates by the Peloponnesus, notwithstanding it is broken up into so many divisions. In fact, Sunium[610] is as much a promontory as Laconia, and not very much less south than Malea,[611] forming a considerable bay,[612] and the Thracian Chersonesus[613] and Sunium[614] form the Gulf of Melas,[615] and likewise those of Macedonia.[616] Added to this, it is manifest that the majority of the distances are falsely stated, thus arguing an ignorance of geography scarcely credible, and so far from requiring geometrical demonstration that it stands out prominent on the very face of the statements. For example, the distance from Epidamnus[617] to the Thermaic Gulf[618] is above 2000 stadia; Eratosthenes gives it at 900. So too he states the distance from Alexandria to Carthage at 13,000[619] stadia; it is not more than 9000, that is, if, as he himself tells us, Caria and Rhodes are under the same meridian as Alexandria,[620] and the Strait of Messina under the same as Carthage,[621] for every one is agreed that the voyage from Caria to the Strait of Sicily does not exceed 9000 stadia.

It is doubtless permissible in very great distances to consider as under one and the same meridian places which are not more east and west of each other than Carthage is west of the Strait;[622] but an error of 3000 stadia is too much; and when he places Rome under the same meridian as Carthage, notwithstanding its being so far west of that city, it is but the crowning proof of his extreme ignorance both of these places, and likewise of the other countries farther west as far as the Pillars of Hercules.

41. Since Hipparchus does not furnish a Geography of his own, but merely reviews what is said in that of Eratosthenes, he ought to have gone farther, and corrected the whole of that writer’s mistakes. As for ourselves, it is only in those particulars where Eratosthenes is correct (and we acknowledge that he frequently errs) that we have thought it our duty to quote his own words, in order to reinstate them in their position, and to defend him when he could be acquitted of the charges of Hipparchus; never failing to break a lance with the latter writer whenever his objections seemed to be the result of a mere propensity to find fault. But when Eratosthenes is grossly mistaken, and the animadversions of Hipparchus are just, we have thought it sufficient in our Geography to set him (Eratosthenes) right by merely stating facts as they are. As the mistakes were so continual and numerous, it was better not to mention them except in a sparse and general manner. This principle in the details we shall strive to carry out. In the present instance we shall only remark, that Timosthenes, Eratosthenes, and those who preceded them, were but ill acquainted with Iberia and Keltica,[623] and a thousand times less with Germany, Britain, and the land of the Getæ and Bastarnæ.[624] Their want of knowledge is also great in regard to Italy, the Adriatic, the Euxine, and the countries north of these. Possibly this last remark may be regarded as captious, since Eratosthenes states, that as to distant countries, he has merely given the admeasurements as he finds them supplied by others, without vouching for their accuracy, although he sometimes adds whether the route indicated is more or less in a right line. We should not therefore subject to a too rigorous examination distances as to which no one is agreed, after the manner Hipparchus does, both in regard to the places already mentioned, and also to those of which Eratosthenes has given the distance from Hyrcania to Bactria and the countries beyond, and those from Colchis to the Sea of Hyrcania. These are points where we should not scrutinize him so narrowly as [when he describes] places situated in the heart of our continent,[625] or others equally well known; and even these should be regarded from a geographical rather than a geometrical point of view. Hipparchus, at the end of the second book of his Commentaries on the Geography of Eratosthenes, having found fault with certain statements relative to Ethiopia, tells us at the commencement of the third, that his strictures, though to a certain point geographical, will be mathematical for the most part. As for myself, I cannot find any geography there. To me it seems entirely mathematical; but Eratosthenes himself set the example; for he frequently runs into scientific speculations, having little to do with the subject in hand, and which result in vague and inexact conclusions. Thus he is a mathematician in geography, and in mathematics a geographer; and so lies open to the attacks of both parties. In this third book, both he and Timosthenes get such severe justice, that there seems nothing left for us to do; Hipparchus is quite enough.