=148. Exploration of the West Coast of Africa; difficulties, real and imagined.=—The great achievement of Portuguese navigation was the discovery of the sea route to India around Africa. The coast of the northwest corner of Africa was well known to sailors of several European countries, and the belief was current in many minds that circumnavigation was possible. Some Genoese sailors had actually attempted to reach India in this way in the thirteenth century, but they had disappeared without leaving a trace. There was all the difference in the world between the theory and the practice of European navigators; the limit of their voyages had practically always been Cape Bojador, far north on the west coast. A strong inshore current and short but furious storms made coasting dangerous. The coast of dreary sand dunes afforded no good anchorage; mist or dust dimmed the air and frightened sailors with the thought that they were actually entering the sea of darkness; Cape Bojador was a forbidding obstacle in that it projected far out beyond the coast line, and was supposed to be extended by perilous reefs. Furthermore, most people submitted to the opinion of ancient philosophers, that the tropics were uninhabitable by reason of the intense heat of a blazing sun, which approached nearer the earth in those regions. [Illustration: DISCOVERIES OF THE PORTUGUESE See Sections 148-149.] =149. Discovery of the Cape of Good Hope (1487) and of the sea route to India (1498).=—Under the stimulus of Prince Henry the Portuguese passed Cape Bojador in 1434, and were rewarded on a more extended voyage about ten years afterward by the discovery of Cape Verde. The name, “Green Cape,” is significant; the explorers had passed the southern edge of the desert and found a watered country with waving palms. In this enterprise, as in most others, the first steps proved to be the hardest. Though progress was steady it was slow, and at the death of Prince Henry in 1460 the Portuguese had not passed beyond Sierra Leone. They had, however, accumulated valuable experience and gained confidence; the long period of preparation fitted them to advance more rapidly as time went on. In 1471 they passed the equator, without the scorching that some had feared; and in 1487, under Diaz, they turned the southern extremity of the Continent, named by the sailor the Cape of Storms, but renamed Cape of Good Hope by the King, as an augury for the future. The illness and death of the King prevented the Portuguese from utilizing their discovery immediately; but in July, 1497, Vasco da Gama was despatched with a fleet bound for India, which anchored at Calicut (southwest coast; _not_ Calcutta), in May, 1498. Oceanic commerce with India had begun, and the tolls and charges which had hampered trade by the land routes were things of the past. [Illustration: Map of the known world in the time of Columbus.]