Greek writers

Home -Greek mythology -Greek writers -Eratosthenes of Cyrene

Eratosthenes of Cyrene

Eratosthenes of Cyrene was a Greek mathematician, astronomer, geographer and poet. He was born in 276 BC (Cyrene) and died in 194 BC (Alexandria).

The main work of Eratosthenes of Cyrene is the Geography of the Hypomnemena. Here he describes the history of geography since the time of Homer, but tries to free the science from all mythological stories. He identifies Anaximander and Hecataeus as the first geographers. He himself propounded the theory that the earth is round. He was also interested in the causes of tides and the like. He also attempted to create a comprehensive map of the world at that time by establishing distances between significant points.

Eratosthenes laid the foundations of geography as a science in its own right. He was the first to use the terms geography, latitude and longitude.

He attempted to measure the size of the earth by comparing the angles of the sun's rays at noon in Alexandria and in Syene (modern-day Aswan; it is close to the Tropic of Cancer and during the summer solstice the sun shines there perpendicularly overhead, at the zenith, and objects cast almost no shadow) and from measuring the distance between these locations. He eventually calculated the circumference of the Earth around the meridian to be about 40,000 km, which is almost an exact figure.

He went on to try to regionalise the world, in which he was the very first person to do so, leaving aside the familiar division of the world of that time into Europe, Asia and Libya. The author assigned borders to seas, rivers and mountain ranges. He also referred to nature, and only in a rather marginal way to its typical representatives. He also listed the tribes that live in that part of the world or what the inhabitants look like.