d. According to the mode of
navigation, which then prevailed, they held their course along the
shore, and by following that direction, they must have encountered
almost insuperable difficulties, in the attempt to pass the cape;
their want of skill was, however, compensated by a fortunate
accident. A sudden squall drove them out to sea, and when they
expected every moment to perish, landed them on an unknown island,
which, from their happy escape, they named Porto Santo. They returned
to Portugal with the good tidings, and were received with the
applause due to fortunate adventurers. The following year, prince
Henry sent out three ships to take possession of the new island; a
fixed spot on the horizon, towards the south, resembling a small
black cloud, soon attracted the attention of the settlers, and the
conjecture suggested itself that it might be land. Steering towards
it, they arrived at a considerable island, uninhabited, and covered
with wood, which, on that account, they called Madeira.

By these voyages, the Portuguese became accustomed to a bolder
navigation, and at length, in 1433, Gilianez, one of prince Henry's
captains, by venturing out into the open sea, succeeded in doubling
Cape Bojador, which, until then, had been regarded as impassable.
This successful voyage, which the ignorance of the age placed on a
level with the most famous exploits recorded in history, opened a new
sphere to navigation, as it discovered the vast continent of Africa,
still washed by the Atlantic Ocean, and stretching towards the south.
A rapid progress was then made along the shores of the Sehara, and
the Portuguese navigators were not long in reaching the fertile
regions watered by the Senegal and the Gambia.

The early part of this progress was dreary in the extreme; they saw
nothing before them but a wild expanse of lifeless earth and sky,
naked rocks and burning sands, stretching immeasurably into the
exterior, and affording no encouragement to any project of
settlement. After, however, passing Cape Blanco, the coast began to
improve in appearance, and when they saw the ivory and gold brought
down from the interior, those regions began to excite the lust of
conquest. This was, however, an undertaking beyond the means of any
force which had as yet sailed from Portugal. In 1443, however, Nuno
Tristan discovered the island of Arguin, and as Gonzalo da Centra was
in 1445 killed by a party of negroes, in attempting to ascend a sma