"Eratosthenes." YourDictionary, n.d. Web. 15 October 2018. <http://www.yourdictionary.com/Eratosthenes>.
Eratosthenes. (n.d.). Retrieved October 15th, 2018, from http://www.yourdictionary.com/Eratosthenes
Third century BC
Greek mathematician, astronomer, and geographer who devised a map of the world, estimated the circumference of the earth and the distance to the moon and the sun, and constructed a method for finding prime numbers.
24) followed Eratosthenes rather than Aristotle, but with sympathies which went out more to the human interests than the mathematical basis of geography.
Varro was also the author of a Cosmographia, or Chorographia, a geographical poem imitated from the Greek of Eratosthenes or of Alexander of Ephesus, surnamed Lychnus; and of an Ephemeris, a hexameter poem on weather-signs after Aratus, from which Virgil has borrowed.
Ptolemy Euergetes (247-222 B.C.) rendered the greatest service to geography by the protection and encouragement of Eratosthenes, whose labours gave the first ap proximate knowledge of the true size of the spherical The .
Eratosthenes (276-196 B.C.) used most probably a solstitial armilla for measuring the obliquity of the ecliptic. Hipparchus (160-125 B.C.) probably used an armillary sphere of four rings.