176 A TROPICAL DEPENDENCY ploration and settlement which was to lead to the discovery of the passage of the Cape of Good Hope, and so to revolutionise European history. A curious theory still prevailed amongst the ignorant that at the Equator the* sea ran dry, and that the passage of ships would be found barred by sand. No sailor having as yet dared like Columbus to put boldly out to sea, the Portuguese movement crept round the African coast, and the sandbanks of the West African harbours served during the early explorations to confirm the common view. Each was taken in turn to represent the last step which could be safely made. It was considered a great feat when a man in Prince Henry's service courageously doubled Cape Bogador, and two others explored the coast at Angra de Cintra in 1435. Cape Blanco followed in 1441. The banks of Arguin were discovered in 1443, and Cape Verde and the mouth of the Senegal in 1444 and 1445. Trade was opened on the Senegal with the natives, and after this the Portuguese discovery of Gambia, Sierra Leone, and the Gold Coast, rapidly followed. The lastnamed coast was explored by two Portuguese sailors in 1 47 1, and the quantity of gold which they obtained was so great as to give to their first landing-place the name which it has always kept of The Mine or Elmina. Within a few years the Portuguese had established trading stations along the coast, and in i486, having built a first fort and church at Elmina, the King of Portugal took the title of Lord of Guinea. In 1481, at the moment when Sonni AH had driven the King of Mossi out of the province of Walata, and was preparing to strengthen his own hold upon the capital of that province by the construction of a canal from Timbuctoo, the Portuguese had taken to Lisbon and were receiving there with great honour a certain prince of the Joloffs, or black branch of the Fulani people, who inhabited the territory to the south of the Senegal, lying between that river and the Atlantic coast. This visit is interesting, as giving one of the earliest authentic descriptions which we possess of the Fulah