Another element in the conception of a Terra Australis was added by Marinus of Tyre and Ptolemy of Alexandria. Eratosthenes (226 had made the eastern coast of the African continent terminate in about 12° N. At the Land of Cinnamon, whence it was supposed oriental spices were brought. Hipparchus (160 prolonged the coast ih definitely towards the south. But Marinus (about 100 perhaps basing his representation on misunderstood reports of Greek travellers, diverted the African coast towards the east at about 15° 30' S., and produced it to about the longitude of the Golden Chersonese, at which point he made it trend northwards to meet an extension of Asia, trending southwards immediately beyond the Magnus Sinus, or Gulf of Siam. The Indian Ocean thus became an inland sea. This scheme was not upset until the true form of Africa had been discovered, and even after that time it survived in many sixteenth-century maps in the eastern and isolated position which they gave to Zanzibar.