AROUND: After reading the June 10 ‘Round the Square about the Summer Solstice, local resident Clayton Vecellio was pleased to share additional information pertaining to the solstice. In Aswan, Egypt the Summer Solstice is marked by how deep the sun shines into an ancient well.

According to an article, provided by Vecellio, in the third century B.C. in Alexandria, Egypt, the Greek scholar Eratosthenes relied on both geometry and reports of the sun’s annual appearance almost directly over Aswan (on the Summer Solstice) to calculate the circumference of the earth — arriving at an estimate close to the actual distance. Eratosthenes successors put the figure for the earth’s circumference at far less, giving Christopher Columbus the mistaken idea that India lay half as far from Portugal if traveling west across the Atlantic ocean, than as if one were to travel east by land.

Eratosthenes was not only the first to calculate the circumference of the earth correctly, according to the World History Encyclopedia, he also was able to calculate the earth’s axial tilt. In addition to being an astronomer and mathematician, Eratosthenes was also a geographer and poet. Perhaps though beyond his calculations of the roundness of earth, he is best known for his mathematical innovation — the Sieve of Eratosthenes, which identified prime numbers and also, his position as the head of the grand library housed in Alexandria.

Today, he is remembered as one of “the greatest polymaths of antiquity and many of the conclusions he reached and terms he coined are still used today,” said the World History Encyclopedia.