Eratosthenes of Cyrene (c. 276–c. 194 BC) was a Greek geographer, astronomer and mathematician. Around 240 BC he was appointed librarian at the Great Library at Alexandria. He is sometimes credited with coining the term ‘geography’ to describe the study of the earth. He was somewhat unkindly nicknamed ‘Beta’ as he was considered to be second best in many subjects. Strabo (Bk II Chap 4.4) was quite critical of Eratosthenes. Nevertheless, Eratosthenes is the first person known to have calculated the Earth’s circumference and measured the tilt of the Earth’s axis and his work led to the most accurate maps and globes for a thousand years.
Dhani Irwanto noted that “Eratosthenes was also the first geographer to incorporate parallels and meridians within his cartographic depictions, attesting to his understanding of the spherical nature of the earth.”(a)
Eratosthenes unwittingly entered the Atlantis debate around 250 BC, when, apparently, he was the first to place the Pillars of Heracles at the Strait of Gibraltar, while many contend that prior to that the ‘Pillars’ were located at the Strait of Sicily or was, according to Servius, a term applied simultaneously to more than one location, indicating the limit of general maritime knowledge at any given period or as I am inclined to believe, the term had over time become just a metaphor, rather than a reference to a specific location! I consider it highly relevant that no writer prior to Eratosthenes had referred to the Pillars of Heracles being located at Gibraltar. It is not unreasonable to conclude that this silence reflects the lack of knowledge possessed by the ancient Greeks regarding the western Mediterranean, which only improved gradually, as their colonising and trading expanded westward.
2010 saw the publication of the first English translation of Eratosthenes’ Geographika by Duane W. Roller.