He points out as a most interesting subject for disquisition the fact of our finding, often quite inland, two or three thousand stadia from the sea, vast numbers of muscle, oyster, and scallop-shells, and salt-water lakes. (The Geography of Strabo, I, iii, 3, 4)
There is no doubt that Eratosthenes was one of the most pre-eminent scholars of his time, accumulating a vast body of knowledge covering chronology, geography, grammar, literary criticism, mathematics, philosophy and poetry. To his critics, however, he was Beta (the second letter of the Greek alphabet), the scholar who never achieved the highest rank in any of the fields he worked in. To Strabo
he frequently runs into scientific speculations, having little to do with the subject in hand, and which result in vague and inexact conclusions. Thus he is a mathematician in geography, and in mathematics, a geographer; and so lies open to the attacks of both parties. (The Geography of Strabo, I, i, 41)
His supporters, however, nicknamed him Pentathlos, the well-rounded competitors, since as a genuine polymath he had demonstrated his mastery of every area of learning.
Around 195 BC, however, the onset of ophthalmia took away his sight. Unable to read, or to observe nature, depression followed, and Eratosthenes reputedly opted to starve himself to death. He died the following year, aged 82 in Alexandria.