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.
Greek mathematician and astronomer who is best known for making an accurate estimate of the circumference of the Earth by measuring the angle of the Sun's rays at two different locations at the same time. He also invented a method for listing the prime numbers that are less than any given number.
(person) 275?-195? b.c.; Gr. geographer, astronomer, & mathematician.
Eratosthenes Sentence Examples
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.
His geography was based more immediately on the work of his predecessor, Marinus of Tyre, and on that of Hipparchus, the follower and critic of Eratosthenes.
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 .
It was upon a map based upon such a source that Eratosthenes (276-196 B.C.) measured the distance between Syene and Alexandria which he required for his determination of the length of a degree.