The Portuguese sent many exploring expeditions along the coast of Africa, and in the course of a century they had circumnavigated the continent and planted colonies all along the shores of the Atlantic and the Indian oceans. Bartholmew Dias having discovered the Cape of Good Hope, the reigning sovereign of Portugal determined to prosecute the explorations still further, with the object of discovering a passage to India. This discovery was made by the intrepid and illustrious mariner, Vasco de Gama, November 20, 1497, a little more than five years after the discovery of America. He pursued his voyage along the eastern coast of Africa, discovering Natal, Mozambique, a number of islands, and finding people in a high stage of commercial advancement, with well-built cities, ports, mosques for the worship of Allah according to the Mohammedan faith, and carrying on a considerable trade with India and the Spice Islands. Of this trade, Portugal long retained supremacy. Other European powers also meantime established colonies at different places on the African coast, so that in the sixteenth century a considerable portion of the outer shell, so to say, had been examined The vast interior, however, long remained unexplored, and much of it remains an utterly unknown primeval wilderness to this day. The settlements and colonies of the Portuguese, French, Dutch, and English were for commercial purposes only, and added very little to the general stock of information. [Illustration: VIEW OF ZANZIBAR.] It was not until a year after the adoption of the Constitution of the United States that any organized effort in behalf of discoveries in Africa was made. In the city of London a Society for the Exploration of Interior Africa was formed in 1788, but it was not until seven years afterwards, that the celebrated Mungo Park undertook his first expedition. Thus it was more than three hundred years from the discovery of the Cape of Good Hope before even a ray of light began to penetrate the darkness of benighted Africa. Meantime, great empires had been overthrown and others established in their place and beneficent governments founded on both continents of the western world.