Marinus of Tyre

Marinus of Tyre, (ca. 70 - 130 A.D., Greek: Μαϝίνος ο Τϝϝιος, also rendered as Marinos of Tyre) was a Phoenician geographer, cartographer and mathematician, who founded mathematical geography.

Biography and historical context
Originally from Syria,, Marinus is thought to have lived both in the city of Tyre and in Rhodes. He and his work were a precursor to that of the great Greek/Egyptian geographer Claudius Ptolemy (90 - 168 A.D.), who used Marinus' work as a source for his Geographia, and acknowledges his great obligations to him. Apart from Ptolemy, Marinus is also cited by the Arab geographer al-Masudi. Beyond this little is known of his life.

Contribution to geography
He introduced improvements to the construction of maps and developed a system of nautical charts. His chief legacy is that he first assigned to each place a proper latitude and longtitude; he used a "Meridian of the Isles of the Blessed (Canary Islands or Cape Verde Islands)" as zero meridian, and the parallel of Rhodes for measurements of latitude. Works used by Ptolemy include Marinus' Geography, as well as his "Corrected Geographical Tables", which are often dated to AD 114, though he may have been a near-contemporary of Ptolemy. Marinus estimated a length of 90,000 stadia for the parallel of Rhodes, corresponding to a circumference of the Earth of 33,300 km, about 17% less than the actual value. (Both numbers depend upon the length assigned to the Greek stade).

He also carefully studied the works of his predecessors and the diaries of travellers. His maps were the first in the Roman Empire to show China. Around 120 A.D., Marinus wrote that the habitable world was bounded on the west by the Fortunate Islands. The text of his geographical treatise however is lost. He also invented the equirectangular projection, which is still used in map creation today. A few of Marinus' opinions are reported by Ptolemy. Marinus was of the opinion that the Okeanos was separated into an eastern and a western part by the continents (Europe, Asia and Africa). He thought that the inhabited world stretched in latitude from Thule (Shetland) to Agisymba (Tropic of Capricorn) and in longitude from the Isles of the Blessed to Shera (China). Marinus also coined the term Antarctic, referring to the opposite of the Arctic Circle.