the Eastern Ocean, let your men ask for Sofala and the Island of the Moon (Madagascar), and they will find pilots to take them to India." [Footnote 56: ? Diaz Point, at the _Serra Parda_ or "Dark Hills" of Barros.] [Footnote 57: Some way beyond Cape Agulhas, and immediately to the east of the River Gauritz.] Yet another chapter of discoveries was opened by King John's expeditions for the ascent of the Western Nile, and for the exploration of the North-East Passage to Cathay. Neither of these achieved complete success, but some more light was gained upon the interior of Africa (where the Portuguese made such notable advances in the sixteenth century); it has even been claimed, but apparently without foundation, for the explorers of John II, that a Portuguese discovery of Novaia Zemlya rewarded their enterprise. The great voyage of Vasco da Gama (1497-9) connected and completed the various aims of Portuguese enterprise, to which Prince Henry had given a permanent and organised form. Though he was not able to see in his own lifetime the fulfilment of his plans, both the method of a South-East Passage, and the men who finally discovered it, were, in a true sense, his--were inseparably associated with his work. The lines of Portuguese advance, a generation after his death, continued to follow his initiative so closely, that, when a different route to the Indies was suggested by Columbus, the government of John II refused to treat it seriously. And yet it was to the Infant's movement--in part, at least--that Columbus owed his conception. "It was in Portugal," says Ferdinand Columbus, "that the Admiral began to surmise that if men could sail so far south, one might also sail west and find lands in that direction." In another place[58] it will be questioned how far a Portuguese movement America-wards can be credited to the mariners of Prince Henry's own time. It is plain that, whether he or his captains ever thought favourably of the chances of the Western route, he and they alike devoted their main energies to its rival, the Eastern or African coasting way. It is equally plain, on the other hand, that the Infant's work produced a new interest in the world-science of geography throughout Christendom, and so was indirectly responsible for quite as much as it directly aimed at accomplishing. [Footnote 58: See the section of this Introduction on the "Atlantic Islands," especially pp. ciii-cvi.] AFRICAN EXPLORATION PRELIMINARY TO PRINCE HENRY'S WORK.