[1] IN his Second Book Eratosthenes endeavours to correct some errors in geography, and offers his own views on the subject, any mistakes in which we shall endeavour in our turn to set right. He is correct in saying that the inductions of mathematics and natural philosophy should be employed, and that if the earth is spheroidal like the universe, it is inhabited in all parts; together with some other things of this nature. Later writers do not agree with him as to the size of the earth, ¹ nor admit his measurement. However Hipparchus, when noting the celestial appearances for each particular locality, adopts his admeasurements, saying that those taken for the meridian of Meroe, ² Alexandria, and the Dnieper, differ but very slightly from the truth. Eratosthenes then enters into a long discussion concerning the figure of the globe, proving that the form of the earth together with the water is spheroidal, as also the heavens. This however we imagine was foreign to his purpose, and should have been disposed of in the compass of a few words.

[2] After this he proceeds to determine the breadth of the habitable earth: he tells us, that measuring from the meridian of Meroe ³ to Alexandria, there are 10,000 stadia. From thence to the Hellespont ⁴ about 8100. Again; from thence to the Dnieper, 5000; and thence to the parallel of Thule, ⁵ which Pytheas says is six days’ sail north from Britain, and near the Frozen Sea, other 11,500. To which if we add 3400 stadia above Meroe in order to include the Island of the Egyptians, ⁶ the Cinnamon country, and Taprobane, ⁷ there will be in all 38,000 stadia.

[3] We will let pass the rest of his distances, since they are something near,—but that the Dnieper is under the same parallel as Thule, what man in his senses could ever agree to this? Pytheas, who has given us the history of Thule, is known to be a man upon whom no reliance can be placed, and other writers who have seen Britain and Ierne, ⁸ although they tell us of many small islands round Britain, make no mention whatever of Thule. The length of Britain itself is nearly the same as that of Keltica, ⁹ opposite to which it extends. Altogether it is not more than 5000 stadia in length, its outermost points corresponding to those of the opposite continent. In fact the extreme points of the two countries lie opposite to each other, the eastern extremity to the eastern, and the western to the western: the eastern points are situated so close as to be within sight of each other, both at Kent and at the mouths of the Rhine. But Pytheas tells us that the island [of Britain] is more than 20,000 stadia in length, and that Kent is some days’ sail from France. With regard to the locality of the Ostimii, and the countries beyond the Rhine, ¹⁰ as far as Scythia, he is altogether mistaken. The veracity of a writer who has been thus false in describing countries with which we are well acquainted, should not be too much trusted in regard to unknown places.

[4] Further, Hipparchus and many others are of opinion that the parallel of latitude of the Dnieper does not differ from that of Britain; since that of Byzantium and Marseilles are the same. The degree of shadow from the gnomon which Pytheas states he observed at Marseilles being exactly equal to that which Hipparchus says he found at Byzantium; the periods of observation being in both cases similar. ¹¹ Now from Marseilles to the centre of Britain is not more than 5000 stadia; and if from the centre of Britain we advance north not more than 4000 stadia, we arrive at a temperature in which it is scarcely possible to exist. Such indeed is that of Ierne. ¹² Consequently the far region in which Eratosthenes places Thule must be totally uninhabitable. By what guesswork he arrived at the conclusion that between the latitude of Thule and the Dnieper there was a distance of 11,500 stadia I am unable to divine.

[5] Eratosthenes being mistaken as to the breadth [of the habitable earth], is necessarily wrong as to its length. The most accurate observers, both ancient and modern, agree that the known length of the habitable earth is more than twice its breadth. Its length I take to be from the [eastern] extremity of India ¹³ to the [westernmost] point of Spain; ¹⁴ and its breadth from [the south of] Ethiopia to the latitude of Ierne. Eratosthenes, as we have said, reckoning its breadth from the extremity of Ethiopia to Thule, was forced to extend its length beyond the true limits, that he might make it more than twice as long as the breadth he had assigned to it. He says that India, measured where it is narrowest, ¹⁵ is 16,000 stadia to the river Indus. If measured from its most prominent capes it extends 3000 more. ¹⁶ Thence to the Caspian Gates, 14,000. From the Caspian Gates to the Euphrates, ¹⁷ 10,000. From the Euphrates to the Nile, 5000. ¹⁸ Thence to the Canopic ¹⁹ mouth, 1300. From the Canopic mouth to Carthage, 13,500. From thence to the Pillars at least 8000. Which make in all 70,800 stadia. To these [he says] should be added the curvature of Europe beyond the Pillars of Hercules, fronting the Iberians, and inclining west, not less than 3000 stadia, and the headlands, including that of the Ostimii, named Cabaeum, ²⁰ and the adjoining islands, the last of which, named Uxisama, ²¹ is distant, according to Pytheas, a three days’ sail. But he added nothing to its length by enumerating these last, viz. the headlands, including that of the Ostimii, the island of Uxisama, and the rest; they are not situated so as affect the length of the earth, for they all lie to the north, and belong to Keltica, not to Iberia; indeed it seems but an invention of Pytheas. Lastly, to fall in with the general opinion that the breadth ought not ²² to exceed half the length, he adds to the stated measure of its length 2000 stadia west, and as many east.

[6] Further, endeavouring to support the opinion that it is in accordance with natural philosophy to reckon the greatest dimension of the habitable earth from east to west, he says that, according to the laws of natural philosophy, the habitable earth ought to occupy a greater length from east to west, than its breadth from north to south. The temperate zone, which we have already designated as the longest zone, is that which the mathematicians denominate a continuous circle returning upon itself. So that if the extent of the Atlantic Ocean were not an obstacle, we might easily pass by sea from Iberia to India, ²³ still keeping in the same parallel; the remaining portion of which parallel, measured as above in stadia, occupies more than a third of the whole circle: since the parallel drawn through Athens, ²⁴ on which we have taken the distances from India to Iberia, does not contain in the whole 200,000 stadia. Here too his reasoning is incorrect. For this speculation respecting the temperate zone which we inhabit, and whereof the habitable earth is a part, devolves properly on those who make mathematics their study. But it is not equally the province of one treating of the habitable earth. For by this term we mean only that portion of the temperate zone where we dwell, and with which we are acquainted. But it is quite possible that in the temperate zone there may be two or even more habitable earths, especially near the circle of latitude which is drawn through Athens and the Atlantic Ocean. After this he returns to the form of the earth, which he again declares to be spheroidal. Here he exhibits the same churlishness we have previously pointed out, and goes on abusing Homer in his old style. He proceeds:

[7] There has been much argument respecting the continents. Some, considering them to be divided by the rivers Nile and Tanais, ²⁵ have described them as islands; while others suppose them to be peninsulas connected by the isthmuses between the Caspian and the Euxine Seas, and between the Erythraean Sea ²⁶ and Ecregma. ²⁷ He adds, that this question does not appear to him to be of any practical importance, but rather, as Democritus observed, a bone of contention for angry litigants. Where there are no precise boundary marks, columns, or walls, as at Colyttus and Melitè, ²⁸ it is easy for us to say such a place is Colyttus, and such another Melitè, but not so easy to show the exact limits: thus disputes have frequently arisen concerning certain districts; that, for instance, between the Argives and Lacedaemonians concerning [the possession of] Thyrea, ²⁹ and that between the Athenians and Boeotians relative to Oropus. ³⁰ Further, in giving names to the three continents, the Greeks did not take into consideration the whole habitable earth, but merely their own country and the land exactly opposite, namely, Caria, which is now inhabited by the Ionians and other neighbouring tribes. In course of time, as they advanced further and daily became acquainted with new countries, this their division came to be general.”

I take this last part first, and (to use Eratosthenes’ own words, not those of Democritus) willing to pick my bone of contention, inquire, whether they who first made the division of the three continents were the same persons as those who first desired to distinguish their own land from that of the Carians opposite, or whether they were only acquainted with Greece, Caria, and some few other adjoining countries, and not with Europe, Asia, or Africa; but that others who followed them, and were able to write a description of the habitable earth, were the real authors of the division into three continents. How did he know that these were not the men who made this division of the habitable earth? And he who divided the earth into three parts, giving to each portion the name of continent, could he not form in his mind a just idea of that taken as a whole, which he had so parcelled out. But if indeed he were not acquainted with the whole habitable earth, but merely made a division of some part thereof, pray what portion of that part did he denominate Asia, or Europe, or simply continent? Such talk is altogether nonsense.

[8] The reasoning of Eratosthenes, however, is still more absurd, when he declares that he sees no advantage in being acquainted with the exact boundaries of countries, and then cites the example of Colyttus and Melitè, which prove just the contrary of his assertion. Surely if a want of certainty respecting the boundaries of Thyrea and Oropus gave rise to war, a knowledge of the limits of different districts must be of practical importance. Will he tell us that the boundaries of districts, or the limits of kingdoms, may be of some service, but when applied to continents it is carrying the matter too far. We reply, it is of equal consequence here. Suppose a dispute between two powerful princes, one claiming the possession of Asia and the other of Africa, to which of these should Egypt, I mean the country called Lower Egypt, appertain. Will any one paws over such cases on account of their rarity? By no means. It is acknowledged by every one that the limits of each continent ought to be defined by some notable boundary, indicated by the configuration of the whole habitable earth. In following out this principle, we should not be very particular if they who determine boundaries by the rivers leave some districts undefined, since the rivers do not reach from sea to sea, nor leave the continents altogether as islands.

[9] At the close of the book Eratosthenes blames the system of those who would divide all mankind into Greeks and Barbarians, and likewise those who recommended Alexander to treat the Greeks as friends, but the Barbarians as enemies. ³¹ He suggests, as a better course, to distinguish them according to their virtues and their vices, since amongst the Greeks there are many worthless characters, and many highly civilized are to be found amongst the Barbarians; witness the Indians and Ariani, ³² or still better the Romans and Carthaginians, whose political system is so beautifully perfect. Alexander, considering this, disregarded the advice which had been offered him, and patronized without distinction any man he considered to be deserving. But we would inquire whether those men who thus divided the human race, abandoning one portion to contempt, and exalting to dignity the other, were not actuated to this because they found that on one side justice, knowledge, and the force of reason reigned supreme, but their contraries on the other. Alexander did not disregard the advice tendered him, but gladly embraced and followed it, respecting the wisdom of those who gave it; and so far from taking the opposite course, he closely pursued that which they pointed out.