Many of the particulars which we have given on the subject of the Roman trade are supplied by Pliny, who wrote his natural history when Rome was in its most flourishing state under the reign of Vespasian.  His works consist of thirty-seven books, the first six comprise the system of the world and the geography as it was then known.  After examining the accounts of Polybius, Agrippa, and Artemidorus, he assigns the following comparative magnitudes to the three great divisions of the earth.  Europe rather more than a third, Asia about a fourth, and Africa about a fifth of the whole.  With few exceptions, his geographical knowledge of the east and of the north, the parts of the world of which the ancients were the most ignorant, was very inaccurate:  he supposes the Ganges to be the north-eastern limit of Asia, and that from it the coast turned to the north, where it was washed by the sea of Serica, between which and a strait, which he imagined formed a communication from the Caspian to the Scythian ocean, he admits but a very small space.  According to the system of Pliny, therefore, the ocean occupied the whole county of Siberia, Mogul Tartary, China, &c.  He derived his information respecting India from the journals of Nearchus, and the other officers of Alexander; and yet such is his ignorance, or the corrupt state of the text, or the vitiated medium through which he received his information, that it is not easy to reconcile his account with that of Nearchus.  Salmasius, indeed, charges him with confounding the east and west in his description of India.  His geography, in the most important particular of the relative distances of places, is rendered of very little utility or authority, from the circumstance pointed out and proved by D’Anville, that he indiscriminately reckons eight stadia to the mile, without reference to the difference between the Greek and Roman stadium.  He has, however, added two articles of information to the geographical and commercial knowledge of the east possessed before his time; the one is the account of the new course of navigation from Arabia to the coast of Malabar, which has been already described; the other is a description of Trapobane, or Ceylon, which, though inaccurate and obscure in many points, must be regarded as a real and important addition to the geographical knowledge of the Romans.

Pliny’s geography of the north is the most full and curious of all antiquity.  After describing the Hellespont, Moeotis, Dacia, Sarmatia, ancient Scythia, and the isles in the Euxine Sea, and proceeding last from Spain, he passes north to the Scythic Ocean, and returns west towards Spain.  The coast of part of the Baltic seems to have been partly known to him; he particularly mentions an island called Baltia, where amber was found; but he supposes that the Baltic Sea itself was connected with the Caspian and Indian Oceans.  Pliny is the first author who names Scandinavia, which he represents as an island, the extent of which was not then known; but by Scandinavia