Before we pass on, it may be advisable to run briefly through the different stages which led to the final opening up of the sea route to India from European ports. The whole project is so intimately bound up with the development of seamanship and navigation, that we cannot well afford to omit this sketch from our purview. It was not by one single effort, but by a series of attempts that the task was performed. The doubling of the Cape of Good Hope by Vasco da Gama in 1497 was notable not merely in itself--not merely because of the long voyage and the attainment of Africa’s southern cape--but because it showed that that ancient instinct was right: there was a sea route to India for those who had the daring to venture. In the year 1415 the furthest south reached was Cape Nun, which is at the south-west extremity of Morocco. Three years later, thanks to the secret which Henry possessed of Macham’s early voyage, two of the Prince’s courtiers were able to rediscover Madeira. In 1433 Cape Bojador, which is on the west coast of the Sahara to the south-east of the Canaries, was doubled by Gillianez. Thus these voyagers were gradually getting nearer to the Equator. The doubling of the last-mentioned headland made such an impression on Pope Martin V that His Holiness bestowed on the King of Portugal all that might thereafter be discovered in Africa and India. This concession led to international disputes in later years. [Illustration: A FIFTEENTH-CENTURY SHIP.] In the year 1441 still more southing was achieved when Gonzales and Tristan reached Cape Blanco on the same West African coast. Three years later and the River Gambia was discovered, and in 1446 the Cape Verde Islands were visited. All this shows the considerable amount of activity which went on during those years when the Prince was at the head of his naval school. We can see, by referring to a map, how steady and persistent was the advance along the west coast of this unknown continent. But then there comes Henry’s death, and there follows a gap in this chain of discoveries. Still, before long this series of southerly voyages was resumed. The aim was ever in the same direction, but the cause of failure is unknown; whether they feared to go too far, whether their provisions ran out, whether their crews were diminished by sickness and death, whether they were not too sure of the condition of their ships one cannot say. Their intention seems to have been to proceed with caution, and possibly they aimed at a more detailed exploration than some of their successors. Perhaps this was owing to the instructions of the Prince.