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THE POPULAR SCIENCE MONTHLY.

distance between the straits and Rhodes. Since the length of the Macedonian coast was placed within its proper limits, no way remained to adjust the distances but to prolong the Thermaic Gulf to the westward, and make of Greece a long peninsula stretching from west to east. The Caspian Sea, owing to reports that had been brought by certain followers of Alexander, appears as an arm of the Northern Ocean. The most striking feature, however, is the representation of India as extending east instead of south, with the Ganges flowing into the Eastern Ocean. This would seem to have arisen in this way: The mouth of the Indus had been reported by Alexander's officers too far south. It was also well known that from the Indus to the island known as Taprobane (Ceylon) there was a long stretch of coast such as is given in the map. But, if this extended southward, it would carry India below what was considered to be the limit of the habitable world, seen in the map at latitude 11° 51' 26". So it was turned away to the eastward. The distance from the Indus to the mouth of the Ganges had been learned through the mission sent to India by Seleucus; and, since the latter river did not enter the sea on the southern coast, it must have an eastern embouchure. But as the traditional limit of the earth—a length twice its breadth—was now reached, it only remained to extend the coast-line to the northward to complete the map.

In accordance with the principles upon which his map was constructed, Eratosthenes said that India could be reached by sailing westward from Spain—a suggestion by which Columbus is said to have been influenced. Before leaving Eratosthenes it may be mentioned that Gosselin contends that this ancient geographer had been preceded by geographers far better informed and more skillful than himself, and that all the best features of his map are due to them. Indeed, he claims that there was a period long before Eratosthenes, when the geography of Europe was as well known as in his (Gosselin's) day, and he even intimates that projected maps, similar to our modern ones, had then been used. His arguments in support of this, however, will not bear scrutiny.

Ptolemy, we have said, prepared the science for the ages of darkness on which the world was soon to enter. In a sense, the first shadows of that darkness had already fallen. The science had gone backward perceptibly since the days of Eratosthenes. True, there was a larger fund of information in regard to the countries of the Roman Empire; but, as we see in Strabo, there was no scientific grasp of the world as a whole. Ptolemy was therefore almost as much of an exception to his age as Hipparchus had been to his. Still he had helps which none of his predecessors had had, such as the works of Strabo and Pliny, and Marin of Tyre, for statements of facts, and those of Eratosthenes, and, above all, Hipparchus for scientific statement. The work which he composed with these helps was to be the standard and