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His brief biography.

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Eratosthenes was a mathematician and astronomer.

He is from Greek Born in 276 BC and died in 196 BC.

He is famous because of his huge accomplishment of being the first person to measure the earth and succeed.

And he was also famous for discovering more about prime numbers.

Facts: He is also known for being a Music theorist and geographer.

He lived and worked in Egypt city.

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who was he?
he was the first man to make an estimate of the circumference of the earth.

where was he from?
he was from Cyrene, Libya

he lived in 276 BCE and died in 194 BCE

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Eratosthenes was a Greek mathmatician/Astronomer. He was born in 276 BE (Cyrene Libya ). And died in 194 BC (Alexandria Eygypt. He knew the famous Greek Mathmatitoin Archmides. he discovered prime numbers and the circumfrence of the earth. They called him penthalos after the Olympians.

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Eldana Biniam

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Who is the guy? Well, Eratosthenes was a mathematician, astronomer, geographer, and poet. born in Cyrene, Libya in 276 BCE, and died in 194 BCE in Alexandria, Egypt at the age of 82. He created the first map of the whole earth with just 2 surface points to measure from! He basically invented longitude and latitude. He also designed a finding prime number system which we now use all the time. And is scientifically called "Sieve of Eratosthenes.”

Sources:

https://www.britannica.com/biography/Eratosthenes

https://www.khanacademy.org/humanities/big-history-project/solar-system-and-earth/knowing-solar-system-earth/a/eratosthenes-of-cyrene

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by Apolline & Jaia

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Eratosthenes was a Greek scientific writer, astronomer, Mathematician, and poet from Cyrene, Libya, but lived in Alexandria, Egypt. He was born in 276 BCE and died in 194 BCE.
He came up with a method to find prime numbers. And made the first measurement of the circumference of the earth.

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Who was he?: He was the Mathematician that discovered PRIME numbers and figured out if the was a sphere.

Where was he from?: Cyrene, Libya

When did he live?: Alexandria, Egypt

Why was he important for mathematics?: He was important to mathematics because he made the theory for prime numbers and prime numbers are now used today

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Eratosthenes is a Greek mathamatition.
Eratosthenes measured Earth's circumference mathematically using two surface points to make the calculation.
Eratosthenes is from Cyrene, Libya.

Eratosthenes was born in about 276 BC and died in about 194 BC. Eratosthenes is famous for his work on prime numbers and for measuring the diameter of the earth

Sources

Eratosthenes | Biography, Discoveries, Sieve, & Facts
https://www.britannica.com

https://mathshistory.st-andrews.ac.uk/Biographies/Eratosthenes/h

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Quick Info

Born

276 BC
Cyrene, North Africa (now Shahhat, Libya)

Died

194 BC
Alexandria, Egypt

Summary

Eratosthenes was a Greek mathematician who is famous for his work on prime numbers and for measuring the diameter of the earth.

Biography

Eratosthenes was born in Cyrene which is now in Libya in North Africa. His teachers included the scholar Lysanias of Cyrene and the philosopher Ariston of Chios who had studied under Zeno, the founder of the Stoic school of philosophy. Eratosthenes also studied under the poet and scholar Callimachus who had also been born in Cyrene. Eratosthenes then spent some years studying in Athens.

The library at Alexandria was planned by Ptolemy I Soter and the project came to fruition under his son Ptolemy II Philadelphus. The library was based on copies of the works in the library of Aristotle. Ptolemy II Philadelphus appointed one of Eratosthenes' teachers Callimachus as the second librarian. When Ptolemy III Euergetes succeeded his father in 245 BC and he persuaded Eratosthenes to go to Alexandria as the tutor of his son Philopator. On the death of Callimachus in about 240 BC, Eratosthenes became the third librarian at Alexandria, in the library in a temple of the Muses called the Mouseion. The library is said to have contained hundreds of thousands of papyrus and vellum scrolls.

Despite being a leading all-round scholar, Eratosthenes was considered to fall short of the highest rank. Heath writes :-

[Eratosthenes] was, indeed, recognised by his contemporaries as a man of great distinction in all branches of knowledge, though in each subject he just fell short of the highest place. On the latter ground he was called Beta, and another nickname applied to him, Pentathlos, has the same implication, representing as it does an all-round athlete who was not the first runner or wrestler but took the second prize in these contests as well as others.
Certainly this is a harsh nickname to give to a man whose accomplishments in many different areas are remembered today not only as historically important but, remarkably in many cases, still providing a basis for modern scientific methods.

One of the important works of Eratosthenes was Platonicus which dealt with the mathematics which underlie Plato's philosophy. This work was heavily used by Theon of Smyrna when he wrote Expositio rerum mathematicarum and, although Platonicus is now lost, Theon of Smyrna tells us that Eratosthenes' work studied the basic definitions of geometry and arithmetic, as well as covering such topics as music.

One rather surprising source of information concerning Eratosthenes is from a forged letter. In his commentary on Proposition 1 of Archimedes' Sphere and cylinder Book II, Eutocius reproduces a letter reputed to have been written by Eratosthenes to Ptolemy III Euergetes. The letter describes the history of the problem of the duplication of the cube and, in particular, it describes a mechanical device invented by Eratosthenes to find line segments and so that, for given segments and , By the famous result of Hippocrates it was known that solving the problem of finding two mean proportionals between a number and its double was equivalent to solving the problem of duplicating the cube. Although the letter is a forgery, parts of it are taken from Eratosthenes' own writing. The letter, which occupies an important place in the history of mathematics, is discussed in detail in . An original Arabic text of this letter was once kept in the library of the St Joseph University in Beirut. However it has now vanished and the details given in come from photographs taken of the letter before its disappearance.

Other details of what Eratosthenes wrote in Platonicus are given by Theon of Smyrna. In particular he described there the history of the problem of duplicating the cube (see Heath ):-
... when the god proclaimed to the Delians through the oracle that, in order to get rid of a plague, they should construct an alter double that of the existing one, their craftsmen fell into great perplexity in their efforts to discover how a solid could be made the double of a similar solid; they therefore went to ask Plato about it, and he replied that the oracle meant, not that the god wanted an alter of double the size, but that he wished, in setting them the task, to shame the Greeks for their neglect of mathematics and their contempt of geometry.
Eratosthenes erected a column at Alexandria with an epigram inscribed on it relating to his own mechanical solution to the problem of doubling the cube :-
If, good friend, thou mindest to obtain from any small cube a cube the double of it, and duly to change any solid figure into another, this is in thy power; thou canst find the measure of a fold, a pit, or the broad basin of a hollow well, by this method, that is, if thou thus catch between two rulers two means with their extreme ends converging. Do not thou seek to do the difficult business of Archytas's cylinders, or to cut the cone in the triads of Menaechmus, or to compass such a curved form of lines as is described by the god-fearing Eudoxus. Nay thou couldst, on these tablets, easily find a myriad of means, beginning from a small base. Happy art thou, Ptolemy, in that, as a father the equal of his son in youthful vigour, thou hast thyself given him all that is dear to muses and Kings, and may be in the future, O Zeus, god of heaven, also receive the sceptre at thy hands. Thus may it be, and let any one who sees this offering say "This is the gift of Eratosthenes of Cyrene".
Eratosthenes also worked on prime numbers. He is remembered for his prime number sieve, the 'Sieve of Eratosthenes' which, in modified form, is still an important tool in number theory research. The sieve appears in the Introduction to arithmetic by Nicomedes.

Another book written by Eratosthenes was On means and, although it is now lost, it is mentioned by Pappus as one of the great books of geometry. In the field of geodesy, however, Eratosthenes will always be remembered for his measurements of the Earth.

Eratosthenes made a surprisingly accurate measurement of the circumference of the Earth. Details were given in his treatise On the measurement of the Earth which is now lost. However, some details of these calculations appear in works by other authors such as Cleomedes, Theon of Smyrna and Strabo. Eratosthenes compared the noon shadow at midsummer between Syene (now Aswan on the Nile in Egypt) and Alexandria. He assumed that the sun was so far away that its rays were essentially parallel, and then with a knowledge of the distance between Syene and Alexandria, he gave the length of the circumference of the Earth as 250,000 stadia.

Of course how accurate this value is depends on the length of the stadium and scholars have argued over this for a long time. The article discusses the various values scholars have given for the stadium. It is certainly true that Eratosthenes obtained a good result, even a remarkable result if one takes 157.2 metres for the stadium as some have deduced from values given by Pliny. It is less good if 166.7 metres was the value used by Eratosthenes as Gulbekian suggests in .

Several of the papers referenced, for example , and , discuss the accuracy of Eratosthenes' result. The paper is particularly interesting. In it Rawlins argues convincingly that the only measurement which Eratosthenes made himself in his calculations was the zenith distance on the summer solstice at Alexandria, and that he obtained the value of 7°12'. Rawlins argues that this is in error by 16' while other data which Eratosthenes used, from unknown sources, was considerably more accurate.

Eratosthenes also measured the distance to the sun as 804,000,000 stadia and the distance to the Moon as 780,000 stadia. He computed these distances using data obtained during lunar eclipses. Ptolemy tells us that Eratosthenes measured the tilt of the Earth's axis with great accuracy obtaining the value of of 180°, namely 23° 51' 15".

The value has fascinated historians of mathematics, for example the papers and are written just to examine the source of this value. Perhaps the most commonly held view is that the value is due to Ptolemy and not to Eratosthenes. Heath argues that Eratosthenes used 24° and that of 180° was a refinement due to Ptolemy. Taisbak agrees with attributing to Ptolemy although he believes that Eratosthenes used the value of 180°. However Rawlins believes that a continued fraction method was used to calculate the value while Fowler proposes that the anthyphairesis (or Euclidean algorithm) method was used (see also ).

Eratosthenes made many other major contributions to the progress of science. He worked out a calendar that included leap years, and he laid the foundations of a systematic chronography of the world when he tried to give the dates of literary and political events from the time of the siege of Troy. He is also said to have compiled a star catalogue containing 675 stars.

Eratosthenes made major contributions to geography. He sketched, quite accurately, the route of the Nile to Khartoum, showing the two Ethiopian tributaries. He also suggested that lakes were the source of the river. A study of the Nile had been made by many scholars before Eratosthenes and they had attempted to explain the rather strange behaviour of the river, but most like Thales were quite wrong in their explanations. Eratosthenes was the first to give what is essentially the correct answer when he suggested that heavy rains sometimes fell in regions near the source of the river and that these would explain the flooding lower down the river. Another contribution that Eratosthenes made to geography was his description of the region "Eudaimon Arabia", now the Yemen, as inhabited by four different races. The situation was somewhat more complicated than that proposed by Eratosthenes, but today the names for the races proposed by Eratosthenes, namely Minaeans, Sabaeans, Qatabanians, and Hadramites, are still used.

Eratosthenes writings include the poem Hermes, inspired by astronomy, as well as literary works on the theatre and on ethics which was a favourite topic of the Greeks. Eratosthenes is said to have became blind in old age and it has been claimed that he committed suicide by starvation.

1. D R Dicks, Biography in Dictionary of Scientific Biography (New York 1970-1990).
SeeTHIS LINK.

2. Biography in Encyclopaedia Britannica.
http://www.britannica.com/biography/Eratosthenes-Of-Cyrene

3. D H Fowler, The mathematics of Plato's academy : a new reconstruction (Oxford, 1987).

4. E P Wolfer, Eratosthenes von Kyrene als Mathematiker und Philosoph (Groningen-Djakarta, 1954).

5. B A El'natanov, A brief outline of the history of the development of the sieve of Eratosthenes (Russian), Istor.-Mat. Issled. (1983), 238-259.

6. F Manna, The Pentathlos of ancient science, Eratosthenes, first and only one of the 'primes' (Italian), Atti Accad. Pontaniana (N.S.) (1986), 37-44.

7. A Muwaf and A N Philippou, An Arabic version of Eratosthenes writing on mean proportionals, J. Hist. Arabic Sci. (1-2) (1981), 174-147.

8. D Rawlins, Eratosthenes' geodest unraveled : was there a high-accuracy Hellenistic astronomy, Isis (1982), 259-265.

9. D Rawlins, The Eratosthenes - Strabo Nile map. Is it the earliest surviving instance of spherical cartography? Did it supply the 5000 stades arc for Eratosthenes' experiment?, Arch. Hist. Exact Sci. (3) (1982), 211-219.

10. C M Taisbak, Eleven eighty-thirds. Ptolemy's reference to Eratosthenes in Almagest I.12, Centaurus 27 (2) (1984), 165-167.

Written by J J O'Connor and E F Robertson
Last Update January 1999

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Born 276 BC Cyrene, North Africa (now Shahhat, Libya) Died 194 BC Alexandria, Egypt Summary Eratosthenes was a Greek mathematician who is famous for his work on prime numbers and for measuring the diameter of the earth. Eratosthenes was born in Cyrene which is now in Libya in North Africa.

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He is from ancient Greek.
He was a mathematician, geographer, poet, astronomer, and music theorist.
Eratosthenes lived in Alexandria, Egypt
https://www.google.com/search?q=Who+was+Eratosthenes%3F&rlz=1CASFKO_enET1020&ei=l9wVY8uDDc6C9u8PytWDkA4&ved=0ahUKEwiLq8mpxf35AhVOgf0HHcrqAOIQ4dUDCA4&uact=5&oq=Who+was+Eratosthenes%3F&gs_lcp=Cgdnd3Mtd2l6EAMyDggAEI8BEOoCEIwDEOUCMg4IABCPARDqAhCMAxDlAjIOCC4QjwEQ6gIQjAMQ5QJKBAhBGABKBAhGGABQsAZYi9sBYN_fAWgCcAF4AIABAIgBAJIBAJgBAKABAaABArABA7gBAsABAQ&sclient=gws-wiz&safe=active&ssui=on

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Yellow Colorful Flower Drawing Phone Wallpaper

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Eratosthenes (born 276 B.C.E in Cyrene and died in 194 B.C.E in Egypt) was a famous Greek scientific writer, astronomer, geographer, mathematician, and poet who made the first measurement of the size of the Earth and its axial tilt. He is also recognized for his mathematical innovation which identified prime numbers.
He is from Cyrene, North Africa ( modern-day Shahhat Libya) and he lived in Alexandria, Egypt for a while. He also devised a method for finding prime numbers.

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https://docs.google.com/presentation/d/1gSSIkORtNhQfQIQGer7kh9jfWY19y6U_rSRiUSCGA3M/edit#slide=id.g150039eda00_2_0

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Eratosthenes                                     By: Veerle

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Eratosthenes                                     By: Veerle

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Eratosthenes was a Greek scientific writer, astronomer, and poet. He was born in 276 BCE in Cyrene, Libya, and died in 194 BCE in Alexandria, Egypt. He was important for mathematics because he mathematically measured the earth's circumference using two surface points to make the calculation.

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Eratosthenes was a Greek polymath, mathematician, geographer, poet, astronomer, and music theorist.

He was born in 276 Bc, Cyrene (Now Libya), and died in 194 Bc. His Occupation was Scholar, Librarian, Poet, and Inventor.

He is the founder of geography and his devotees nicknamed him Pentathlos after the Olympians.

He proposed an algorithm to find prime numbers easily. He also measured the Earth's circumference.

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Eratosthenes, in full Eratosthenes of crane, (born c. 276 BCE, Cyrene, Libya—died c. 194 BCE, Alexandria, Egypt), Greek scientific writer, astronomer, and poet, who made the first measurement of the size of the earth for which any details are known.

His mathematical work is known principally and his geographical work is from the first two books of the Geography of the Greek geographer from the writings of the Greek geometer Strabo.

He is credited with devising an algorithm for finding prime numbers called the sieve of  Eratosthenes.

Fun fact
He was Chief Librarian within about five years. He tutored the children of Ptolemy as the head of the library. Eratosthenes was a friend of Archimedes and made several important contributions to mathematics and science. He invented the armillary sphere, around 255 BC.

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Eratosthenes is born in 276 BCE in Cyrene, Lybia, he was a Mathematician and was known for how he had figured the prime number's algorithm, and for he figured an efficient way to calculate prime numbers, (Eratosthenes created the Sieve of Eratosthenes a procedure for finding prime numbers),In addition to calculating Earth's circumference, he tried to fix the dates of literary and political events since the siege of Troy, and is thought to have created the "armillary sphere" (an early astronomical device for representing the great circles of the heavens).

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Born: 276 BC, Cyrene, Libya, Shahat, LibyaDied: 194 BC, Alexandria, EgyptEducation: Platonic AcademyNationality: Ancient GreekNickname: PentathlosKnown for: Sieve of Eratosthenes; Founder of Geography

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Born: 276 BC, Cyrene, Libya, Shahat, LibyaDied: 194 BC, Alexandria, EgyptEducation: Platonic AcademyNationality: Ancient GreekNickname: PentathlosKnown for: Sieve of Eratosthenes; Founder of Geography

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Eratosthenes was born in 276 BCE in Cyrene, Lybia. He was a greek mathematician and he figured out Prime numbers and Composite numbers. Eratosthenes was not too important because had he not done it somebody else might have.

Hugh Jex

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Eratosthenes was a greek polymath mathematician, geographer, poet, and astronomer. He lived in Cyrene, Libya, Shahat, and Egypt. 4 places! Eratosthenes was very important for math. He discovered/estimated the circumference between the Sun and Earth. On his lowest guess, he got only 50 miles off!

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- Eratosthenes was a famous mathematician
- He was from Cyrene, Libya, Shahat, Libya
- Born: 276 BCE, and Died: 194 BCE. Alexandria, Egypt
- He figured out the Circumference

Matthew Rawlins

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Eratosthenes, born 276 BCE in Cyrene, Lybia was a greek mathematician who calculated the diameter of the Earth with unrivaled accuracy for the time. He put a stick in the dirt at Alexandria and saw that it was at a seven-degree angle as opposed to a zero-degree angle in another city then, he got a servant to pace the distance. Using these measurements, he predicted the Earth's circumference to 50 miles from the actual distance. He died in Alexandria, Egypt in 194 BCE.

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Eratosthenes was born in cyrene, libya (c 276 bce. Alexandria Egypt. Cyene, Libya, Shahat, Libya. Eratosthenes was know for being a pollymath mathimatiction

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Eratosthenes was from Greek and was born in 276 BC and died in 194 BC. He lived in Greek and Libya. He discovered the tilt of the earth's axis and calculated the distance between the earth the sun and the moon. He was also an astronomer and poet.

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1. (born c. 276 BCE, Cyrene, Libya—died c. 194 BCE, Alexandria, Egypt)

2. Greek scientific writer, astronomer, and poet made the first measurement of the size of Earth for which any details are known.

Links:https://www.google.com/search?q=Who+was+Eratosthenes%3F&rlz=1CASFKO_enET1019&oq=Who+was+Eratosthenes%3F&aqs=chrome..69i57j0i512j0i22i30l8.1486j0j15&sourceid=chrome&ie=UTF-8&safe=active&ssui=on

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Eratosthenes of Cyrene (; Greek: [eratostʰénɛːs]; - ) was a Greek polymath: a mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. His work is comparable to what is now known as the study of geography, and he introduced some of the terminology still used today.

He is best known for being the first person known to calculate the circumference of the Earth, which he did by using the extensive survey results he could access in his role at the Library; his calculation was remarkably accurate. He was also the first to calculate Earth's axial tilt, which also proved to have remarkable accuracy. He created the first global projection of the world, incorporating parallels and meridians based on the available geographic knowledge of his era.

Eratosthenes was the founder of scientific chronology; he endeavoured to revise the dates of the main events of the semi-mythological Trojan War, dating the Sack of Troy to 1183 BC. In number theory, he introduced the sieve of Eratosthenes, an efficient method of identifying prime numbers.

He was a figure of influence in many fields. According to an entry in the Suda (a 10th-century encyclopedia), his critics scorned him, calling him Beta (the second letter of the Greek alphabet) because he always came in second in all his endeavours. Nonetheless, his devotees nicknamed him Pentathlos after the Olympians who were well rounded competitors, for he had proven himself to be knowledgeable in every area of learning. Eratosthenes yearned to understand the complexities of the entire world.

The son of Aglaos, Eratosthenes was born in 276 BC in Cyrene. Now part of modern-day Libya, Cyrene had been founded by Greeks centuries earlier and became the capital of Pentapolis (North Africa), a country of five cities: Cyrene, Arsinoe, Berenice, Ptolemias, and Apollonia. Alexander the Great conquered Cyrene in 332 BC, and following his death in 323 BC, its rule was given to one of his generals, Ptolemy I Soter, the founder of the Ptolemaic Kingdom. Under Ptolemaic rule the economy prospered, based largely on the export of horses and silphium, a plant used for rich seasoning and medicine. Cyrene became a place of cultivation, where knowledge blossomed. Like any young Greek at the time, Eratosthenes would have studied in the local gymnasium, where he would have learned physical skills and social discourse as well as reading, writing, arithmetic, poetry, and music.

Eratosthenes went to Athens to further his studies. There he was taught Stoicism by its founder, Zeno of Citium, in philosophical lectures on living a virtuous life. He then studied under Aristo of Chios, who led a more cynical school of philosophy. He also studied under the head of the Platonic Academy, who was Arcesilaus of Pitane. His interest in Plato led him to write his very first work at a scholarly level, Platonikos, inquiring into the mathematical foundation of Plato's philosophies. Eratosthenes was a man of many perspectives and investigated the art of poetry under Callimachus. He wrote poems: one in hexameters called Hermes, illustrating the god's life history; and another in elegiacs, called Erigone, describing the suicide of the Athenian maiden Erigone (daughter of Icarius). He wrote Chronographies, a text that scientifically depicted dates of importance, beginning with the Trojan War. This work was highly esteemed for its accuracy. George Syncellus was later able to preserve from Chronographies a list of 38 kings of the Egyptian Thebes. Eratosthenes also wrote Olympic Victors, a chronology of the winners of the Olympic Games. It is not known when he wrote his works, but they highlighted his abilities.

These works and his great poetic abilities led the pharaoh Ptolemy III Euergetes to seek to place him as a librarian at the Library of Alexandria in the year 245 BC. Eratosthenes, then thirty years old, accepted Ptolemy's invitation and traveled to Alexandria, where he lived for the rest of his life. Within about five years he became Chief Librarian, a position that the poet Apollonius Rhodius had previously held. As head of the library Eratosthenes tutored the children of Ptolemy, including Ptolemy IV Philopator who became the fourth Ptolemaic pharaoh. He expanded the library's holdings: in Alexandria all books had to be surrendered for duplication. It was said that these were copied so accurately that it was impossible to tell if the library had returned the original or the copy. He sought to maintain the reputation of the Library of Alexandria against competition from the Library of Pergamum. Eratosthenes created a whole section devoted to the examination of Homer, and acquired original works of great tragic dramas of Aeschylus, Sophocles and Euripides.

Eratosthenes made several important contributions to mathematics and science, and was a friend of Archimedes. Around 255 BC, he invented the armillary sphere. In On the Circular Motions of the Celestial Bodies, Cleomedes credited him with having calculated the Earth's circumference around 240 BC, with a high precision.

Eratosthenes believed there was both good and bad in every nation and criticized Aristotle for arguing that humanity was divided into Greeks and barbarians, as well as for arguing that the Greeks should keep themselves racially pure. As he aged, he contracted ophthalmia, becoming blind around 195 BC. Losing the ability to read and to observe nature plagued and depressed him, leading him to voluntarily starve himself to death. He died in 194 BC at 82 in Alexandria.

Measurement of Earth's circumference

The measurement of Earth's circumference is the most famous among the results obtained by Eratosthenes, who estimated that the meridian has a length of 252,000 stadia (39,060-40,320 km), with an error on the real value between −2.4% and +0.8% (assuming a value for the stadion between 155 and 160 metres). Eratosthenes described his arc measurement technique, in a book entitled On the measure of the Earth , which has not been preserved. However, a simplified version of the method has been preserved, as described by Cleomedes.

The simplified method works by considering two cities along the same meridian and measuring both the distance between them and the difference in angles of the shadows cast by the sun on a vertical rod (a gnomon) in each city at noon on the summer solstice. The two cities used were Alexandria and Syene (modern Aswan), and the distance between the cities was measured by professional bematists. A geometric calculation reveals that the circumference of the Earth is the distance between the two cities divided by the difference in shadow angles expressed as a fraction of one turn.

Eratosthenes now continued from his knowledge about the Earth. Using his discoveries and knowledge of its size and shape, he began to sketch it. In the Library of Alexandria he had access to various travel books, which contained various items of information and representations of the world that needed to be pieced together in some organized format. In his three-volume work Geography ( Greek: Geographika), he described and mapped his entire known world, even dividing the Earth into five climate zones: two freezing zones around the poles, two temperate zones, and a zone encompassing the equator and the tropics. He had invented geography. He created terminology that is still used today. He placed grids of overlapping lines over the surface of the Earth. He used parallels and meridians to link together every place in the world. It was now possible to estimate one's distance from remote locations with this network over the surface of the Earth. In the Geography the names of over 400 cities and their locations were shown, which had never been achieved before. However, his Geography has been lost to history, although fragments of the work can be pieced together from other great historians like Pliny, Polybius, Strabo, and Marcianus.

The first book was something of an introduction and gave a review of his predecessors, recognizing their contributions that he compiled in the library. In this book Eratosthenes denounced Homer as not providing any insight into what he now described as geography. His disapproval of Homer's topography angered many who believed the world depicted in the Odyssey to be legitimate. He also commented on the ideas of the nature and origin of the Earth: he thought of Earth as an immovable globe while its surface was changing. He hypothesized that at one time the Mediterranean had been a vast lake that covered the countries that surrounded it and that it only became connected to the ocean to the west when a passage opened up sometime in its history.

The second book contains his calculation of the circumference of the Earth. This is where, according to Pliny, "The world was grasped." Here Eratosthenes described his famous story of the well in Syene, wherein at noon each summer solstice, the Sun's rays shone straight down into the city-center well. This book would now be considered a text on mathematical geography.

His third book of the Geography contained political geography. He cited countries and used parallel lines to divide the map into sections, to give accurate descriptions of the realms. This was a breakthrough and can be considered the beginning of geography. For this, Eratosthenes was named the "Father of Modern Geography."

According to Strabo, Eratosthenes argued against the Greek- Barbarian dichotomy. He says Alexander ignored his advisers by his regard for all people with law and government. Strabo says that Eratosthenes was wrong to claim that Alexander had disregarded the counsel of his advisers. Strabo argues it was Alexander's interpretation of their "real intent" in recognizing that "in some people there prevail the law-abiding and the political instinct, and the qualities associated with education and powers of speech".

Eratosthenes was described by the Suda Lexicon as a Πένταθλος (Pentathlos) which can be translated as "All-Rounder", for he was skilled in a variety of things: He was a true polymath. He was nicknamed Beta 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.

Eusebius of Caesarea in his Preparatio Evangelica includes a brief chapter of three sentences on celestial distances (Book XV, Chapter 53). He states simply that Eratosthenes found the distance to the Sun to be "σταδίων μυριάδας τετρακοσίας καὶ ὀκτωκισμυρίας " (literally "of stadia myriads 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 185 m (607 ft), 804,000,000 stadia is 149,000,000 km (93,000,000 mi), approximately the distance from the Earth to the Sun.

Eratosthenes also calculated the Sun's diameter. According to Macrobious, Eratosthenes made the diameter of the Sun to be about 27 times that of the Earth. The actual figure is approximately 109 times.

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.

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. 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.

Eratosthenes proposed a simple algorithm for finding prime numbers. This algorithm is known in mathematics as the Sieve of Eratosthenes.

In mathematics, the sieve of Eratosthenes (Greek: κόσκινον Ἐρατοσθένους), one of a number of prime number sieves, is a simple, ancient algorithm for finding all prime numbers up to any given limit. It does so by iteratively marking as composite, i.e., not prime, the multiples of each prime, starting with the multiples of 2. The multiples of a given prime are generated starting from that prime, as a sequence of numbers with the same difference, equal to that prime, between consecutive numbers. This is the sieve's key distinction from using trial division to sequentially test each candidate number for divisibility by each prime.

Eratosthenes was one of the most pre-eminent scholarly figures of his time, and produced works covering a vast area of knowledge before and during his time at the Library. He wrote on many topics-geography, mathematics, philosophy, chronology, literary criticism, grammar, poetry, and even old comedies. Unfortunately, there are no documents left of his work after the destruction of the Library of Alexandria.

Aujac, G. (2001). Eratosthène de Cyrène, le pionnier de la géographie. Paris: Édition du CTHS. 224p.

Bulmer-Thomas, Ivor (1939-1940). Selections Illustlating the History of Greek Mathematics. Cambridge, Massachusetts: Harvard University Press.

Dorofeeva, A. V. (1988). "Eratosthenes (ca. 276-194 B.C.)". Mat. V Shkole (in Russian) (4): i.

Dutka, J. (1993). "Eratosthenes' measurement of the Earth reconsidered". Arch. Hist. Exact Sci. 46 (1): 55-66. Bibcode:1993AHES...46...55D. doi:10.1007/BF00387726. S2CID 119522892.

El'natanov, B. A. (1983). "A brief outline of the history of the development of the sieve of Eratosthenes". Istor.-Mat. Issled. (in Russian). 27: 238-259.

Fischer, I (1975). "Another look at Eratosthenes' and Posidonius' determinations of the Earth's circumference". Quarterly Journal of the Royal Astronomical Society. 16: 152-167. Bibcode:1975QJRAS..16..152F.

Fraser, P. M. (1970). "Eratosthenes of Cyrene". Proceedings of the British Academy. 56: 175-207.

Fraser, P. M. (1972). Ptolemaic Alexandria. Oxford: Clarendon Press.

Fuentes González, P. P., "Ératosthène de Cyrène", in R. Goulet (ed.), Dictionnaire des Philosophes Antiques, vol. III, Paris, Centre National de la Recherche Scientifique, 2000, pp. 188-236.

Geus K. (2002). Eratosthenes von Kyrene. Studien zur hellenistischen Kultur- und Wissenschaftgeschichte. München: Verlag C.H. Beck. (Münchener Beiträge zur Papyrusforschung und antiken Rechtsgeschichte. Bd. 92) X, 412 S.

Goldstein, B. R. (1984). "Eratosthenes on the "measurement" of the Earth". Historia Math. 11 (4): 411-416. doi:10.1016/0315-0860(84)90025-9.

Gulbekian, E. (1987). "The origin and value of the stadion unit used by Eratosthenes in the third century B.C". Archive for History of Exact Sciences. 37 (4): 359-363. doi:10.1007/BF00417008 (inactive 28 February 2022). JSTOR 41133819.

Honigmann, E. (1929). Die sieben Klimata und die πολεις επισημοι. Eine Untersuchung zur Geschichte der Geographie und Astrologie in Altertum und Mittelalter. Heidelberg: Carl Winter's Universitätsbuchhandlung. 247 S.

Knaack, G. (1907). "Eratosthenes". Pauly-Wissowa VI: 358-388.

Manna, F. (1986). "The Pentathlos of ancient science, Eratosthenes, first and only one of the "primes"". Atti Accad. Pontaniana. New Series (in Italian). 35: 37-44.

Muwaf, A.; Philippou, A. N. (1981). "An Arabic version of Eratosthenes writing on mean proportionals". J. Hist. Arabic Sci. 5 (1-2): 147-175.

Nicastro, Nicholas (2008). Circumference: Eratosthenes and the ancient quest to measure the globe. New York: St. Martin's Press. ISBN 978-0-312-37247-7.

O'Connor, John J.; Robertson, Edmund F., "Eratosthenes", MacTutor History of Mathematics archive, University of St Andrews

Marcotte, D. (1998). "La climatologie d'Ératosthène à Poséidonios: genèse d'une science humaine". G. Argoud, J.Y. Guillaumin (eds.). Sciences exactes et sciences appliquées à Alexandrie (IIIe siècle av J.C. - Ier ap J.C.). Saint Etienne: Publications de l'Université de Saint Etienne: 263-277.

McPhail, Cameron (2011). Reconstructing Eratosthenes' Map of the World: a Study in Source Analysis. A Thesis Submitted for the Degree of Master of Arts at the University of Otago. Dunedin, New Zealand.

Pfeiffer, Rudolf (1968). History of Classical Scholarship From the Beginnings to the End of the Hellenistic Age. Oxford: Clarendon Press.

Rawlins, D. (1982). "The Eratosthenes - Strabo Nile map. Is it the earliest surviving instance of spherical cartography? Did it supply the 5000 stades arc for Eratosthenes' experiment?". Arch. Hist. Exact Sci. 26 (3): 211-219.

Rawlins, D. (2008). "Eratosthenes's large Earth and tiny universe" (PDF). DIO. 14: 3-12. Bibcode:2008DIO....14....3R.

Roller, Duane W. (2010). Eratosthenes' Geography: Fragments collected and translated, with commentary and additional material. Princeton: Princeton University Press. ISBN 978-0-691-14267-8.

Rosokoki, A. (1995), Die Erigone des Eratosthenes. Eine kommentierte Ausgabe der Fragmente, Heidelberg: C. Winter-Verlag

Shcheglov, D.A. (2004/2006). "Ptolemy's System of Seven Climata and Eratosthenes' Geography". Geographia Antiqua 13: 21-37.

Shcheglov, D.A. (2006). "Eratosthenes' Parallel of Rhodes and the History of the System of Climata". Klio. 88 (2): 351-359. doi:10.1524/klio.2006.88.2.351. S2CID 190529073.

Strabo (1917). The Geography of Strabo. Horace Leonard Jones, trans. New York: Putnam.

Thalamas, A. (1921). La géographe d'Ératosthène. Versailles.

Wolfer, E. P. (1954). Eratosthenes von Kyrene als Mathematiker und Philosoph. Groningen-Djakarta.

# data[].attributes.attachment_link.description
Eratosthenes of Cyrene (; Greek: [eratostʰénɛːs]; - ) was a Greek polymath: a mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. His work is comparable to what is now known as the study of geography, and he introduced some of the terminology still used today.

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Eratosthenes, in full Eratosthenes of Cyrene, (born c. 276 BCE, Cyrene, Libya—died c. 194 BCE, Alexandria, Egypt), Greek scientific writer, astronomer, and poet, who made the first measurement of the size of Earth for which any details are known. - cited by Britannica

He is important to mathematics because he is the one who discovered measurement.https://www.britannica.com/biography/Eratosthenes

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Eratosthenes measured Earth's circumference mathematically using two surface points to make the calculation.

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He lived in Cyrene, Libya

He is also from Cyrene, Libya

He is important because Eratosthenes may have been the first to use the word geography. He invented a system of longitude and latitude and made a map of the known world. He also designed a system for finding prime numbers — whole numbers that can only be divided by themselves or by the number 1.

https://www.khanacademy.org/humanities/big-history-project/solar-system-and-earth/knowing-solar-system-earth/a/eratosthenes-of-cyrene#:~:text=Eratosthenes%20may%20have%20been%20the,or%20by%20the%20number%201.

# data[].attributes.body
Eratosthenes, in full Eratosthenes of Cyrene, (born c. 276 bce, Cyrene, Libya—died c. 194 bce, Alexandria, Egypt), Greek scientific writer, astronomer, and poet, who made the first measurement of the size of Earth for which any details are known.

# data[].attributes.attachment_link.readable_text
Eratosthenes of Cyrene (; Greek: [eratostʰénɛːs]; - ) was a Greek polymath: a mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. His work is comparable to what is now known as the study of geography, and he introduced some of the terminology still used today.

He is best known for being the first person known to calculate the circumference of the Earth, which he did by using the extensive survey results he could access in his role at the Library; his calculation was remarkably accurate. He was also the first to calculate Earth's axial tilt, which also proved to have remarkable accuracy. He created the first global projection of the world, incorporating parallels and meridians based on the available geographic knowledge of his era.

Eratosthenes was the founder of scientific chronology; he endeavoured to revise the dates of the main events of the semi-mythological Trojan War, dating the Sack of Troy to 1183 BC. In number theory, he introduced the sieve of Eratosthenes, an efficient method of identifying prime numbers.

He was a figure of influence in many fields. According to an entry in the Suda (a 10th-century encyclopedia), his critics scorned him, calling him Beta (the second letter of the Greek alphabet) because he always came in second in all his endeavours. Nonetheless, his devotees nicknamed him Pentathlos after the Olympians who were well rounded competitors, for he had proven himself to be knowledgeable in every area of learning. Eratosthenes yearned to understand the complexities of the entire world.

The son of Aglaos, Eratosthenes was born in 276 BC in Cyrene. Now part of modern-day Libya, Cyrene had been founded by Greeks centuries earlier and became the capital of Pentapolis (North Africa), a country of five cities: Cyrene, Arsinoe, Berenice, Ptolemias, and Apollonia. Alexander the Great conquered Cyrene in 332 BC, and following his death in 323 BC, its rule was given to one of his generals, Ptolemy I Soter, the founder of the Ptolemaic Kingdom. Under Ptolemaic rule the economy prospered, based largely on the export of horses and silphium, a plant used for rich seasoning and medicine. Cyrene became a place of cultivation, where knowledge blossomed. Like any young Greek at the time, Eratosthenes would have studied in the local gymnasium, where he would have learned physical skills and social discourse as well as reading, writing, arithmetic, poetry, and music.

Eratosthenes went to Athens to further his studies. There he was taught Stoicism by its founder, Zeno of Citium, in philosophical lectures on living a virtuous life. He then studied under Aristo of Chios, who led a more cynical school of philosophy. He also studied under the head of the Platonic Academy, who was Arcesilaus of Pitane. His interest in Plato led him to write his very first work at a scholarly level, Platonikos, inquiring into the mathematical foundation of Plato's philosophies. Eratosthenes was a man of many perspectives and investigated the art of poetry under Callimachus. He wrote poems: one in hexameters called Hermes, illustrating the god's life history; and another in elegiacs, called Erigone, describing the suicide of the Athenian maiden Erigone (daughter of Icarius). He wrote Chronographies, a text that scientifically depicted dates of importance, beginning with the Trojan War. This work was highly esteemed for its accuracy. George Syncellus was later able to preserve from Chronographies a list of 38 kings of the Egyptian Thebes. Eratosthenes also wrote Olympic Victors, a chronology of the winners of the Olympic Games. It is not known when he wrote his works, but they highlighted his abilities.

These works and his great poetic abilities led the pharaoh Ptolemy III Euergetes to seek to place him as a librarian at the Library of Alexandria in the year 245 BC. Eratosthenes, then thirty years old, accepted Ptolemy's invitation and traveled to Alexandria, where he lived for the rest of his life. Within about five years he became Chief Librarian, a position that the poet Apollonius Rhodius had previously held. As head of the library Eratosthenes tutored the children of Ptolemy, including Ptolemy IV Philopator who became the fourth Ptolemaic pharaoh. He expanded the library's holdings: in Alexandria all books had to be surrendered for duplication. It was said that these were copied so accurately that it was impossible to tell if the library had returned the original or the copy. He sought to maintain the reputation of the Library of Alexandria against competition from the Library of Pergamum. Eratosthenes created a whole section devoted to the examination of Homer, and acquired original works of great tragic dramas of Aeschylus, Sophocles and Euripides.

Eratosthenes made several important contributions to mathematics and science, and was a friend of Archimedes. Around 255 BC, he invented the armillary sphere. In On the Circular Motions of the Celestial Bodies, Cleomedes credited him with having calculated the Earth's circumference around 240 BC, with a high precision.

Eratosthenes believed there was both good and bad in every nation and criticized Aristotle for arguing that humanity was divided into Greeks and barbarians, as well as for arguing that the Greeks should keep themselves racially pure. As he aged, he contracted ophthalmia, becoming blind around 195 BC. Losing the ability to read and to observe nature plagued and depressed him, leading him to voluntarily starve himself to death. He died in 194 BC at 82 in Alexandria.

Measurement of Earth's circumference

The measurement of Earth's circumference is the most famous among the results obtained by Eratosthenes, who estimated that the meridian has a length of 252,000 stadia (39,060-40,320 km), with an error on the real value between −2.4% and +0.8% (assuming a value for the stadion between 155 and 160 metres). Eratosthenes described his arc measurement technique, in a book entitled On the measure of the Earth , which has not been preserved. However, a simplified version of the method has been preserved, as described by Cleomedes.

The simplified method works by considering two cities along the same meridian and measuring both the distance between them and the difference in angles of the shadows cast by the sun on a vertical rod (a gnomon) in each city at noon on the summer solstice. The two cities used were Alexandria and Syene (modern Aswan), and the distance between the cities was measured by professional bematists. A geometric calculation reveals that the circumference of the Earth is the distance between the two cities divided by the difference in shadow angles expressed as a fraction of one turn.

Eratosthenes now continued from his knowledge about the Earth. Using his discoveries and knowledge of its size and shape, he began to sketch it. In the Library of Alexandria he had access to various travel books, which contained various items of information and representations of the world that needed to be pieced together in some organized format. In his three-volume work Geography ( Greek: Geographika), he described and mapped his entire known world, even dividing the Earth into five climate zones: two freezing zones around the poles, two temperate zones, and a zone encompassing the equator and the tropics. He had invented geography. He created terminology that is still used today. He placed grids of overlapping lines over the surface of the Earth. He used parallels and meridians to link together every place in the world. It was now possible to estimate one's distance from remote locations with this network over the surface of the Earth. In the Geography the names of over 400 cities and their locations were shown, which had never been achieved before. However, his Geography has been lost to history, although fragments of the work can be pieced together from other great historians like Pliny, Polybius, Strabo, and Marcianus.

The first book was something of an introduction and gave a review of his predecessors, recognizing their contributions that he compiled in the library. In this book Eratosthenes denounced Homer as not providing any insight into what he now described as geography. His disapproval of Homer's topography angered many who believed the world depicted in the Odyssey to be legitimate. He also commented on the ideas of the nature and origin of the Earth: he thought of Earth as an immovable globe while its surface was changing. He hypothesized that at one time the Mediterranean had been a vast lake that covered the countries that surrounded it and that it only became connected to the ocean to the west when a passage opened up sometime in its history.

The second book contains his calculation of the circumference of the Earth. This is where, according to Pliny, "The world was grasped." Here Eratosthenes described his famous story of the well in Syene, wherein at noon each summer solstice, the Sun's rays shone straight down into the city-center well. This book would now be considered a text on mathematical geography.

His third book of the Geography contained political geography. He cited countries and used parallel lines to divide the map into sections, to give accurate descriptions of the realms. This was a breakthrough and can be considered the beginning of geography. For this, Eratosthenes was named the "Father of Modern Geography."

According to Strabo, Eratosthenes argued against the Greek- Barbarian dichotomy. He says Alexander ignored his advisers by his regard for all people with law and government. Strabo says that Eratosthenes was wrong to claim that Alexander had disregarded the counsel of his advisers. Strabo argues it was Alexander's interpretation of their "real intent" in recognizing that "in some people there prevail the law-abiding and the political instinct, and the qualities associated with education and powers of speech".

Eratosthenes was described by the Suda Lexicon as a Πένταθλος (Pentathlos) which can be translated as "All-Rounder", for he was skilled in a variety of things: He was a true polymath. He was nicknamed Beta 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.

Eusebius of Caesarea in his Preparatio Evangelica includes a brief chapter of three sentences on celestial distances (Book XV, Chapter 53). He states simply that Eratosthenes found the distance to the Sun to be "σταδίων μυριάδας τετρακοσίας καὶ ὀκτωκισμυρίας " (literally "of stadia myriads 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 185 m (607 ft), 804,000,000 stadia is 149,000,000 km (93,000,000 mi), approximately the distance from the Earth to the Sun.

Eratosthenes also calculated the Sun's diameter. According to Macrobious, Eratosthenes made the diameter of the Sun to be about 27 times that of the Earth. The actual figure is approximately 109 times.

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.

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. 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.

Eratosthenes proposed a simple algorithm for finding prime numbers. This algorithm is known in mathematics as the Sieve of Eratosthenes.

In mathematics, the sieve of Eratosthenes (Greek: κόσκινον Ἐρατοσθένους), one of a number of prime number sieves, is a simple, ancient algorithm for finding all prime numbers up to any given limit. It does so by iteratively marking as composite, i.e., not prime, the multiples of each prime, starting with the multiples of 2. The multiples of a given prime are generated starting from that prime, as a sequence of numbers with the same difference, equal to that prime, between consecutive numbers. This is the sieve's key distinction from using trial division to sequentially test each candidate number for divisibility by each prime.

Eratosthenes was one of the most pre-eminent scholarly figures of his time, and produced works covering a vast area of knowledge before and during his time at the Library. He wrote on many topics-geography, mathematics, philosophy, chronology, literary criticism, grammar, poetry, and even old comedies. Unfortunately, there are no documents left of his work after the destruction of the Library of Alexandria.

Aujac, G. (2001). Eratosthène de Cyrène, le pionnier de la géographie. Paris: Édition du CTHS. 224p.

Bulmer-Thomas, Ivor (1939-1940). Selections Illustlating the History of Greek Mathematics. Cambridge, Massachusetts: Harvard University Press.

Dorofeeva, A. V. (1988). "Eratosthenes (ca. 276-194 B.C.)". Mat. V Shkole (in Russian) (4): i.

Dutka, J. (1993). "Eratosthenes' measurement of the Earth reconsidered". Arch. Hist. Exact Sci. 46 (1): 55-66. Bibcode:1993AHES...46...55D. doi:10.1007/BF00387726. S2CID 119522892.

El'natanov, B. A. (1983). "A brief outline of the history of the development of the sieve of Eratosthenes". Istor.-Mat. Issled. (in Russian). 27: 238-259.

Fischer, I (1975). "Another look at Eratosthenes' and Posidonius' determinations of the Earth's circumference". Quarterly Journal of the Royal Astronomical Society. 16: 152-167. Bibcode:1975QJRAS..16..152F.

Fraser, P. M. (1970). "Eratosthenes of Cyrene". Proceedings of the British Academy. 56: 175-207.

Fraser, P. M. (1972). Ptolemaic Alexandria. Oxford: Clarendon Press.

Fuentes González, P. P., "Ératosthène de Cyrène", in R. Goulet (ed.), Dictionnaire des Philosophes Antiques, vol. III, Paris, Centre National de la Recherche Scientifique, 2000, pp. 188-236.

Geus K. (2002). Eratosthenes von Kyrene. Studien zur hellenistischen Kultur- und Wissenschaftgeschichte. München: Verlag C.H. Beck. (Münchener Beiträge zur Papyrusforschung und antiken Rechtsgeschichte. Bd. 92) X, 412 S.

Goldstein, B. R. (1984). "Eratosthenes on the "measurement" of the Earth". Historia Math. 11 (4): 411-416. doi:10.1016/0315-0860(84)90025-9.

Gulbekian, E. (1987). "The origin and value of the stadion unit used by Eratosthenes in the third century B.C". Archive for History of Exact Sciences. 37 (4): 359-363. doi:10.1007/BF00417008 (inactive 28 February 2022). JSTOR 41133819.

Honigmann, E. (1929). Die sieben Klimata und die πολεις επισημοι. Eine Untersuchung zur Geschichte der Geographie und Astrologie in Altertum und Mittelalter. Heidelberg: Carl Winter's Universitätsbuchhandlung. 247 S.

Knaack, G. (1907). "Eratosthenes". Pauly-Wissowa VI: 358-388.

Manna, F. (1986). "The Pentathlos of ancient science, Eratosthenes, first and only one of the "primes"". Atti Accad. Pontaniana. New Series (in Italian). 35: 37-44.

Muwaf, A.; Philippou, A. N. (1981). "An Arabic version of Eratosthenes writing on mean proportionals". J. Hist. Arabic Sci. 5 (1-2): 147-175.

Nicastro, Nicholas (2008). Circumference: Eratosthenes and the ancient quest to measure the globe. New York: St. Martin's Press. ISBN 978-0-312-37247-7.

O'Connor, John J.; Robertson, Edmund F., "Eratosthenes", MacTutor History of Mathematics archive, University of St Andrews

Marcotte, D. (1998). "La climatologie d'Ératosthène à Poséidonios: genèse d'une science humaine". G. Argoud, J.Y. Guillaumin (eds.). Sciences exactes et sciences appliquées à Alexandrie (IIIe siècle av J.C. - Ier ap J.C.). Saint Etienne: Publications de l'Université de Saint Etienne: 263-277.

McPhail, Cameron (2011). Reconstructing Eratosthenes' Map of the World: a Study in Source Analysis. A Thesis Submitted for the Degree of Master of Arts at the University of Otago. Dunedin, New Zealand.

Pfeiffer, Rudolf (1968). History of Classical Scholarship From the Beginnings to the End of the Hellenistic Age. Oxford: Clarendon Press.

Rawlins, D. (1982). "The Eratosthenes - Strabo Nile map. Is it the earliest surviving instance of spherical cartography? Did it supply the 5000 stades arc for Eratosthenes' experiment?". Arch. Hist. Exact Sci. 26 (3): 211-219.

Rawlins, D. (2008). "Eratosthenes's large Earth and tiny universe" (PDF). DIO. 14: 3-12. Bibcode:2008DIO....14....3R.

Roller, Duane W. (2010). Eratosthenes' Geography: Fragments collected and translated, with commentary and additional material. Princeton: Princeton University Press. ISBN 978-0-691-14267-8.

Rosokoki, A. (1995), Die Erigone des Eratosthenes. Eine kommentierte Ausgabe der Fragmente, Heidelberg: C. Winter-Verlag

Shcheglov, D.A. (2004/2006). "Ptolemy's System of Seven Climata and Eratosthenes' Geography". Geographia Antiqua 13: 21-37.

Shcheglov, D.A. (2006). "Eratosthenes' Parallel of Rhodes and the History of the System of Climata". Klio. 88 (2): 351-359. doi:10.1524/klio.2006.88.2.351. S2CID 190529073.

Strabo (1917). The Geography of Strabo. Horace Leonard Jones, trans. New York: Putnam.

Thalamas, A. (1921). La géographe d'Ératosthène. Versailles.

Wolfer, E. P. (1954). Eratosthenes von Kyrene als Mathematiker und Philosoph. Groningen-Djakarta.

# data[].attributes.attachment_link.description
Eratosthenes of Cyrene (; Greek: [eratostʰénɛːs]; - ) was a Greek polymath: a mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. His work is comparable to what is now known as the study of geography, and he introduced some of the terminology still used today.

# data[].attributes.body
Eratosthenes was born in 267 BCE and died in 194 BCE.
He was a Greek scientific writer, astronomer, and poet, who made the first measurement of the size of Earth
He lived in Alexandria, Egypt, part of Ancient Greece.

# data[].attributes.body
he live in 276 bce. to 273 bce

He was a greek mathematician, geographer, astronomer, historian, scholar, philosopher and poet. and he has become known for his estimate of the circumference of the earth. At the behest of the Egyptian kings of the Ptolemy dynasty, he built the library of Alexandria, the most important library of antiquity.

# data[].attributes.body
Eratosthenes was born in 267 BCE and died in 194 BCE.
He was a Greek scientific writer, astronomer, and poet, who made the first measurement of the size of Earth
He lived in Alexandria, Egypt, part of Ancient Greece.