A diagram depicts a circle with a triangle and square inscribed within it, intersected by a central axis, illustrating the geometric principles used for mapping.

Therefore, because the distance is gathered to be of two parts, perhaps it is not inappropriate that we place the same distance from the Aurea Chersonesus Golden Peninsula/Malay Peninsula to Zabas, and from there to Cattigara. Furthermore, it is not necessary to reduce the distance which is from the Aurea Chersonesus to Zabas, since it exists parallel to the equinoctial equator, and because the intermediate region is extended opposite to the meridian. But it is fitting to contract the distance which is from Zabas to Cattigara, because the navigation inclines toward the south and the east, so that we may take a position which is parallel to the equinoctial. If, therefore, we attribute half of the parts to each distance, on account of the uncertainty of their excess, and we have subtracted from the parts that are from Zabas to Cattigara—ten, and again a third of that, on account of the inclination—we will also have the distance from the Aurea Chersonesus to Cattigara, in its position, as almost parallel to the equinoctial, of seventeen parts, with almost a sixth. But it has been shown that the distance from the Cory promontory as far as the Aurea Chersonesus is of thirty-four and four-fifths parts. Therefore, the whole distance which is from Cory as far as Cattigara is gathered to be of almost fifty-two parts. However, the meridian which passes through the beginnings of the Indus river is, according to Marinus, a little more to the west than the northern promontory of Taprobane Sri Lanka, which is situated opposite to Cory. But Taprobane is distant from the meridian which passes through the mouths of the Betys Guadalquivir river by eight hourly intervals, and indeed by one hundred and twenty parts. The meridian, however, which passes through the mouths of the Betys is five parts from that which passes through the Fortunate Islands Canary Islands, so that the meridian through Cory is distant from the Fortunate Islands by a little more than one hundred and twenty-five parts; but the one through Cattigara from that which passes through the Fortunate Islands to that same promontory is a little more than one hundred and seventy-seven parts, according to almost the same distance of parts which are gathered through the Rhodian parallel. But let it be assumed that the entire longitude as far as the metropolis of the Sinae China is of one hundred and eighty whole parts, and indeed of twelve hours, because all agree that it is more eastern than Cattigara; through the Rhodian longitude, seventy-two thousand stadia will be gathered almost.

CAPVT XV.

Therefore, we have generally contracted the distances, and the longitudes toward the east, and the latitudes toward the south, because of the causes set forth. Furthermore, we think the positions of cities are often worthy of amendment in particular instances, in which Marinus made conflicting or inconsistent expositions, on account of the diffuse and various compositions published in different commentaries, just as in those which he believed to be opposite. For he says that Tarraco Tarragona, Spain is situated opposite to Iulia Caesarea, writing that the meridian passes through this and the Pyrenean mountains, which, however, are not a little more eastern than Tarraco. And he opposes Pachynum to Leptis Magna, and Himera to Thenae, with the distance from Pachynum to Himera gathered at almost four hundred stadia, whereas that which is from Leptis to Thenae is over one thousand five hundred, as is evident from those things which Timosthenes writes. Again, he says that Tergestum Trieste is opposed to Ravenna, and that from the inner gulf of the Adria which is near the Tiliaventum river, Tergestum is distant toward the summer sunrise by four hundred stadia, but Ravenna toward the winter sunrise by one thousand stadia. Similarly, he reports the Chelidonian islands to be opposite to Canopus, and Acamas to Paphos, and Paphos to Sebennytos. However, the distance which he himself posits from the Chelidonian islands to Acamas is one thousand stadia, and that from Canopus to Sebennytos is posited by Timosthenes as two hundred and ninety; if they were to lie under the same meridians, the distance ought to be far greater, because it subtends the circumference of a larger parallel. Again, he says that Pisa is distant from Ravenna toward the Libonotus South-southwest wind by seven hundred stadia; yet through the division of the climates, and also of the hourly intervals, he places Pisa in the third hourly interval, but Ravenna in the fourth. And when he says that Noviomagus is fifty-nine miles south of Britain, he shows it to be more northerly through the climates. He also arranges Athos under the parallel which passes through the Hellespont, but he places Amphipolis and the surrounding places, which are situated above Athos and the mouths of the Strymon, in the fourth climate, and below the Hellespont. Similarly, when almost the whole of Thrace is situated under the parallel which passes through Byzantium, he nevertheless establishes all of its inland cities in the climate which is above this parallel. Furthermore, he says we shall establish Trapezus Trabzon under the parallel which passes through Byzantium...