CHAPTER XIII.--The Portuguese cross the Equator from Guinea to
Congo--John II. conceives the idea of a Route by Sea to the Indies--His Artifices to prevent the Interference of other Nations--The Overland Journey of Covillam to India--The Voyage of Bartholomew Diaz--The Doubling of the Tremendous Cape--Its Baptism by the King--Injurious Effects of Success upon Portuguese Ambition 133