This notion of an antipodal world in the southern hemisphere will have especial interest for us when we come to deal with the voyages of Vespucius. The idea seems to have originated in a guess of Hipparchus that Taprobane--the island of Ceylon, about which the most absurd reports were brought to Europe--might be the beginning of another world. This is very probable, says Mela, with delightful _naivete_, because Taprobane is inhabited, and still we do not know of anybody who has ever made the tour of it.[364] Mela's contemporary, the elder Pliny, declares that Taprobane "has long been regarded" as part of another world, the name of which is Antichthon, or Opposite-Earth;[365] at the same time Pliny vouchsafes three closely-printed pages of information about this mysterious country. Throughout the Middle Ages the conception of some sort of an antipodal inhabited world was vaguely entertained by writers here and there, but many of the clergy condemned it as implying the existence of people cut off from the knowledge of the gospel and not included in the plan of salvation. [Footnote 364: "Taprobane aut grandis admodum insula aut prima pars orbis alterius Hipparcho dicitur; sed quia habitata, nec quisquam circummeasse traditur, prope verum est." _De Situ Orbis_, iii. 7.] [Footnote 365: "Taprobanen alterum orbem terrarum esse, diu existimatum est, Antichthonum appellatione." _Hist. Nat._, vi. 24.] [Sidenote: The fiery zone.] As to the possibility of crossing the torrid zone, opinion was not unanimous. Greek explorers from Alexandria (cir. B. C. 100) seem to have gone far up the Nile toward the equator, and the astronomer Geminus quotes their testimony in proof of his opinion that the torrid zone is inhabitable.[366] Panaetius, the friend of the younger Scipio Africanus, had already expressed a similar opinion. But the flaming theory prevailed. Macrobius, writing about six hundred years later, maintained that the southernmost limit of the habitable earth was 850 miles south of Syene, which lies just under the tropic of Cancer.[367] Beyond this point no man could go without danger from the fiery atmosphere. Beyond some such latitude on the ocean no ship could venture without risk of being engulfed in some steaming whirlpool.[368] Such was the common belief before the great voyages of the Portuguese. [Footnote 366: Geminus, _Isagoge_, cap. 13.] [Footnote 367: Macrobius, _Somnium Scipionis_, ii. 8. Strabo (ii. 5, Sec.Sec. 7, 8) sets the southern boundary of the Inhabited World 800 miles south of Syene, and the northern boundary at the north of Ireland.]