Eratosthenes

, a Greek of Cyrene, librarian of Alexandria under king Euergetes, the son of Ptolemy Philadelphia, was born in the year 275 B. C. He cultivated at once poetry, grammar, philosophy, mathematics, and excelled in the first and the last. He was styled the Cosmographer, the measurer of the universe, the second Plato, and was the first who discovered a method of measuring the bulk and circumference of the earth. He constructed the first observatory, and observed the obliquity of the ecliptic, and found out also a method of knowing the primitive numbers, that is, the numbers that have no common measure but unity, which was named the sieve of Eratosthenes. This philosopher likewise composed a treatise for completing the analysis, and he solved the problem of the duplication of the cube, by means of an instrument composed of several sliders. Having attained the age of eighty, and being oppressed with infirmities, he voluntarily died of hunger, in the year 195 B. C. He described in Greek, the reigns of thirty-eight Theban kings, which had been omitted by Manetho, out of the sacred records of the Egyptians, at Thebes, and this at the command of king Euergetes. Apollodorus transcribed this catalogue out of Eratosthenes, and Sycellus out of Apollodorus. This catalogue or Laterculus of Eratosthenes is generally owned to be the most authentic Egyptian account of all others now extant, and reaches from the beginning of that kingdom after the deluge, till the days of the judges, if not also till the days of Solomon: and by Diccearchus’s connection of one of its kings with an antediluvian king of Egypt on one side, and with the first olympiad of Jphitus on the other, we gain another long and authentic series of heathen chronology during all that time. The little that remains to us of the works of Eratosthenes was printed at Oxford in 1672, 8vo- There are two other editions one in the “Uranologia” of father Petau, 1630; and the other at Amsterdam, in the same size, 1703; and in 1795, John Conr. Schaubach edited the “Catasterismi cutninterpretatione Latina et commentariis,” including a dissertation by the learned Heyne, printed at Gottingen, 1795, 8vo. ¹