3.

True, dear Polybius, (one might say,) this error [of Dicæarchus] is manifested by the proof which you yourself have given when you inform us that from the Peloponnesus to Leucas673 there are 700 stadia; from thence to Corcyra674 the same number; and the same number again from Corcyra to the Ceraunian Mountains;675 and from the Ceraunian Mountains to Iapygia,676 following the coast of Illyria on the right, 6150 stadia.677 But the statement of Dicæarchus, that the distance from the Strait of Sicily to the Pillars is 7000 stadia, and also your view of the matter, are both of them equally incorrect. For almost every one is agreed that the distance measured straight across the sea is 12,000 stadia, and this coincides with the received calculation of the length of the inhabited earth, which is estimated at above 70,000 stadia; the western portion of this from the Gulf of Issus678 to the extreme western point of Iberia is little less than 30,000 stadia, and is thus calculated: from the Gulf of Issus to Rhodes 5000 stadia; from thence to Cape Salmonium,679 which forms the eastern extremity of Crete, 1000; the length of Crete to Criu-metopon680 above 2000; thence to Cape Pachynus681 in Sicily 4500, and from Pachynus to the Strait of Sicily above 1000 stadia; the run from the Strait to the Pillars 12,000; and lastly, from the Pillars to the extremity of the said promontory682 of Iberia, about 3000 stadia.683

In addition to this, the perpendicular684 is not correct, supposing it true that Narbonne lies under almost the same parallel as Marseilles, and that this latter place is under the same parallel as Byzantium; which is the opinion of Hipparchus. Now the line drawn across the sea lies under the same parallel as the Strait [of the Pillars] and Rhodes; and the distance from Rhodes to Byzantium, which both lie under the same meridian, is estimated at about 5000 stadia; to which the above-mentioned perpendicular ought to be equal. But since they say that from the recess of the Galatic Gulf, the greatest distance across the sea from Europe to Libya is 5000 stadia, it seems to me that either there is some error in this statement, or that at this point Libya must incline very much to the north, and so come under the same parallel as the Pillars. Polybius is likewise mistaken in telling us that this said perpendicular terminates close to Sardinia; for instead of being close to Sardinia, it is far west thereof, having almost the whole of the sea of Liguria685 between it and that island. Besides this he makes the length of the sea-coast too great; but this [error] is not so considerable [as the two preceding].