management of the instruments then employed for making astronomical
observations at sea, and in the construction of nautical charts. Some
traces of nautical discoveries along the western coast of Africa still
remained in ancient authors; particularly of the reported voyages of
Menelaus, Hanno, Eudoxus, and others. From an attentive consideration of
these, Don Henry and his scientific coadjutor were encouraged to hope for
the accomplishment of important discoveries in that direction; and they
were certainly incited in these views by the rooted enmity which had so
long rankled among the Christian inhabitants of Spain and Portugal
against the Moors, who had formerly expelled their ancestors from the
greatest part of the peninsula, and with whom they had waged an incessant
war of several centuries in recovering the country from their grasp.

SECTION II.

_Discovery of the Madeira Islands._

After some time usefully employed in acquiring and diffusing a competent
knowledge of cosmopographical, nautical, and astronomical science, Don
Henry resolved to devote a considerable portion of the revenue which he
enjoyed as Grand Master of the Order of Christ, in continuing and
extending those projects of nautical discovery which had long occupied
his attention. Accordingly, about the year 1418, a new expedition of
discovery was fitted out for the express purpose of attempting to
surmount the perils of Cape Bojador. In this expedition Juan Gonzales
Zarco and Tristan Vaz Texeira, two naval officers of the household of Don
Henry, volunteered their services; and, embarking in a vessel called a
_barcha_[3], steered for the tremendous cape. The Portuguese were
hitherto ignorant of the prevailing winds upon the coast of Africa, and
the causes by which their influence is varied or increased. Near the land,
and between the latitudes of 28 deg. and 10 deg. north, a fresh gale almost
always blows from the N.E. Long sand-banks, which extend a great way out
to sea, and which are extremely difficult to be distinguished in the
mornings and evenings, and the prevailing currents, were powerful
obstacles to the enterprise of these navigators. About six leagues off
Cape Bojador, a most violent current continually dashes upon the breakers,
which presented a most formidable obstacle to the brave but inexperienced
mariners. Though their voyage was short, they encountered many dangers;
and, before they could reach the cape, they were encountered by a