<Tr> <Th> Known for </Th> <Td> <P> Sieve of Eratosthenes </P> Foundation of Geography </Td> </Tr> <P> Sieve of Eratosthenes </P> <P> Eratosthenes of Cyrene (/ ɛr əˈtɒsθəniːz /; Greek: Ἐρατοσθένης ὁ Κυρηναῖος, IPA: (eratosthénɛːs); c. 276 BC--c. 195 / 194 BC) was a Greek mathematician, geographer, poet, astronomer, and music theorist . He was a man of learning, becoming the chief librarian at the Library of Alexandria . He invented the discipline of geography, including the terminology used today . </P> <P> He is best known for being the first person to calculate the circumference of the Earth, which he did by applying a measuring system using stadia, a standard unit of measure during that time period . His calculation was remarkably accurate . He was also the first to calculate the tilt of the Earth's axis (again with remarkable accuracy). Additionally, he may have accurately calculated the distance from the Earth to the Sun and invented the leap day . He created the first map of the world, incorporating parallels and meridians based on the available geographic knowledge of his era . </P>

Who was the first to measure the earth circumference