Editing Eratosthenes (section)

===Achievements===
Eratosthenes was described by the [[Suda Lexicon]] as a Πένταθλος (Pentathlos) which can be translated as "All-Rounded", for he was skilled in a variety of things; he was a true polymath. His opponents nicknamed him "Number 2" because he was great at many things and tried to get his hands on every bit of information but never achieved the highest rank in anything; [[Strabo]] accounts Eratosthenes as a mathematician among geographers and a geographer among mathematicians.<ref name="Dicks1971" />
* [[Eusebius of Caesarea]] in his ''[[Preparatio Evangelica]]'' includes a brief chapter of three sentences on celestial distances ([http://www.tertullian.org/fathers/eusebius_pe_15_book15.htm Book XV], Chapter 53). He states simply that Eratosthenes found the distance to the Sun to be "{{lang|grc|σταδίων μυριάδας τετρακοσίας καὶ ὀκτωκισμυρίας}}" (literally "of [[Stadia (length)|stadia]] [[myriad]]s 400 and 80,000") and the distance to the Moon to be 780,000 stadia. The expression for the distance to the Sun has been translated either as 4,080,000 stadia (1903 translation by E. H. Gifford), or as 804,000,000 stadia (edition of Edouard des Places, dated 1974–1991). The meaning depends on whether Eusebius meant 400 myriad plus 80,000 or "400 and 80,000" myriad. With a stade of {{cvt|185|m|||}}, 804,000,000 stadia is {{cvt|149000000|km|||}}, approximately the distance from the Earth to the Sun.
* Eratosthenes also calculated the Sun's diameter. According to [[Macrobius]], Eratosthenes made the diameter of the Sun to be about 27 times that of the Earth.<ref name="Smith2005" /> The actual figure is approximately 109 times.<ref name="caltech" />
* During his time at the Library of Alexandria, Eratosthenes devised a calendar using his predictions about the [[ecliptic]] of the Earth. He calculated that there are 365 days in a year and that every fourth year there would be 366 days.<ref name="manawatu" />
* He was also very proud of his solution for [[Doubling the Cube]]. His motivation was that he wanted to produce catapults. Eratosthenes constructed a mechanical line drawing device to calculate the cube, called the mesolabio. He dedicated his solution to King Ptolemy, presenting a model in bronze with it a letter and an epigram.<ref name="zhumud" /> Archimedes was Eratosthenes' friend and he, too, worked on the war instrument with mathematics. Archimedes dedicated his book ''The Method'' to Eratosthenes, knowing his love for learning and mathematics.<ref name="chondros" />