MARINUS OF TYRE

(Tyre, Syria, Roman Empire, fl. c. 100 CE),

geography.

Marinus was the author of a number of works on cartography, which are known solely from what Ptolemy (second century CE) relates about them in Book I of his Geography. Ptolemy speaks of Marinus as the most recent author to have dealt with the problem of constructing a map of the oikoumenê, the “inhabited world” (in effect, the part of the world known to Greco-Roman civilization). Most of what Ptolemy writes about Marinus is a review of his errors and infelicities. But at the outset he praises the thoroughness of his research, his critical attitude to his sources, and his readiness to correct his own work, and he makes it clear that the broad geographical conception portrayed in the Geography as well as the bulk of the detailed data are taken from Marinus.

Marinus assumed a spherical Earth having a circumference of 180,000 stades. (The size of the ancient geographers’ stade is disputed, but that is not terribly important, because ancient geodesy relied on very crude distance estimates.) His oikoumenê comprised the three continents of Europe, Libya (Africa), and Asia, and he believed that Asia was joined to Libya not only at the head of the Red Sea but also by land south and east of the “sea of India” (the Indian Ocean), which was thus wholly enclosed and not connected to the ocean lying east of Europe and Libya. The northernmost known locality was Thoulê (the Shetlands?), slightly south of the Arctic Circle, and the westernmost was the Isles of the Blest (the Canaries). Ptolemy took over these assumptions. But Marinus deduced from the reports of various travelers that the oikoumenê extended 24^o south of the equator and 225^o east of the Isles of the Blest, much further in either direction than Ptolemy was willing to accept. The remotest places to the east of which his sources knew appear to have corresponded to China and Southeast Asia, and the southernmost to parts of the east coast of Africa a few degrees south of the equator. So far as scholars know, Greco-Roman geographical knowledge never surpassed these limits.

Marinus’s most detailed and accurate information, of course, pertained to the Roman Empire and its immediate neighbors. Roughly two-thirds of the eight thousand or so localities listed in Ptolemy’s geographical catalog were within the empire, and it is striking that in these regions Ptolemy’s data reflect geographical conditions around the first decade of the second century CE, about half a century before Ptolemy wrote the Geography. This is probably when Marinus was active. Elsewhere, and especially in describing India and lands further east, Ptolemy had more recent informants.

Marinus advocated using a rectangular grid of meridians and parallels (i.e., a cylindrical projection) for drawing a world map. According to Ptolemy’s report, Marinus did not actually produce a map in accordance with the last of his cartographical treatises, and it is not clear whether Ptolemy had access to any map executed according to Marinus’s data or had to rely entirely on his writings.

BIBLIOGRAPHY

Berggren, J. Lennart, and Alexander Jones. Ptolemy’s Geography: An Annotated Translation of the Theoretical Chapters. Princeton, NJ: Princeton University Press, 2000.

Honigmann, Ernst. “Marinos von Tyros.” In Realencyclopädie der Klassischen Altertumswissenschaft, vol. 28. Stuttgart, Germany, 1930. Reviews the evidence for Marinus’s writings.

Alexander Jones