Eratosthenes of Cyrene – the First Geographer
Eratosthenes of Cyrene (/ˌɛrətɒsˈθiːniːz/; Ancient Greek: Ἐρατοσθένης ὁ Κυρηναῖος, romanized: Eratosthénēs ho Kyrēnaîos; c. 276 BC – c. 194 BC) was a Greek mathematician, the first geographer, and astronomer. He is credited with being the first person to calculate the circumference of the Earth, which he did by applying a measuring system using stadia, a …