dria- and Rhodes to be no more than 3750 ſtadia, and taking this interval to be (what it is not) a forty-eighth part of the earth's circumference, he reduced his computation to 180,000 ſtadia[1]; and this meaſure, in which the number of degrees aſſigned by Poſidonius, and the number of ſtadia meaſured by Eratoſthenes, are made uſe of, was received by Marinus[2] of Tyre, and others, and is generally aſcribed to Ptolemy, becauſe he makes uſe of it in his geography.
Beſides, Eratoſthenes, who lived during the interval between Ariſtotle and Poiidonius, and 123. years later than Ariſtotle, had concluded the circumference of the earth to- be 250,000 ſtadia; or, as moſt account it, 252,000 ſtadia, from an obſervation of the diſtance between Syene and Alexandria[3], and the reſpective meridian altitude[4] of the fun at each place.
- ↑ Strabo, lib. ii. p. 95.
- ↑ Long's Aſtronomy, vol. i. p. 128.
- ↑ Eratoſthenis Geograph. Fragment, p. 53.
- ↑
Arat. Phaenom. Edit. Oxon. 1672. p. 37. καταϛερίσμων.
De ſtadiis Eratoſthenis nibil pro certo aſſirmare audeo, quale ſtadium in animo habuerit. Hoc tamcn expectandum eſſet, aliud Eraſothenis ſi habuerit ſtadium, a Strabane eſſet indicatum. Nunc autem Strabo octo ſtadia mille paſſibus Romanis adnumerat, cui convenit Plinius, centum viginti quinque paſſus Romano: Radio tribuens ſemperque, ubi Eraſothenis ſtadia paſſuum numero exhibet, hac dimenſione utens. Secundum hæe itaque terræ maximuſcirculuo eſſet 31500 milliaria Romana, ſeu 6300 milliaria noſtra (Germanic) geographic. Nam unum milliare geographic um eſt æquale quinque milliariis Romanis. Error itaque eſſet 900 mill. geograph. Nam ſecundum noſtrorum dimenſiones geographicas ambitus circuli maximi eſt 5400 mill. geograph. Ex hoc ipſo apparere vidctur, eo ſtadio, quod Olympic um vacant, uſum fuiſſe Eraſothenem. Etenim ſecundum ejus dimeticndi rationem, magnitudinem circuli maximi nimiam æſtmare ſane debebat. Secundum accuratiorem dimennonem autem non niſi 600 ſtadia Olympica uni gradui convenient. Stadium Ægyptiacum, quorum quindecim ſunt æqualia uni milliario Romano, nullo modo dimenſioni Eratoſthenes poteſt accommodari adverſus ſtadium Græcum minus teſtatur locus Strabonis. Eraſothenis Fragm. Edit. a G. C. F. Seidel, Goettingæ, 1789. p. 58.Univerſum autem hunc circuit um Eraſofthenes in omnium quidem literanam ſubtilitate et in hac utique præter cæzteros ſolate, quam cunctis probare video ducentorum quinquaginta,
