rce, which had enriched the maritime
states of Italy. He sought every means and opportunity by which he could
increase or render more accurate his information respecting the western
coast, and the interior of Africa: and it is probable that the relations of
certain Jews and Arabs, respecting the gold mines of Guinea, weighed
strongly with him in the enterprizes which he planned, encouraged, and
accomplished.

It is not true, however, that he was the inventor of the astrolobe and the
compass, or the first that put these instruments into the hands of
navigators, though he undoubtedly was an excellent mathematician, and
procured the best charts and instruments of the age: the use and
application of these, he taught in the best manner to those he selected to
command his ships.

With respect to the compass, we have already stated all that is certainly
known respecting its earliest application to the purposes of navigation.
The sea astrolobe, which is an instrument for taking the altitude of the
sun, stars, &c., is described by Chaucer, in 1391, in a treatise on it,
addressed to his little son, Louis; and Purchas informs us, that it was
formerly applied only to astronomical purposes, but was accommodated to the
use of seamen by Martin Behaim, at the command of John II., king of
Portugal, about the year 1487.

About the year 1418, when Prince Henry first began his plan of discovery,
Cape Nun, in latitude 28 deg. 40', was the limit of European knowledge on the
coast of Africa. With this part of the coast, the Portuguese had become
acquainted in consequence of their wars with the Moors of Barbary. In 1418,
two of Henry's commanders reached Cape Boyada in latitute 26 deg. 30'; but the
Cape was not actually doubled till 1434. The Canary islands were visited
during the same voyage that the Cape was discovered: Madeira was likewise
visited or discovered; it was first called St. Laurence, after the saint of
the day on which it was seen, and afterwards Madeira, on account of its
woods. In 1420, the Portuguese set fire to these woods, and afterwards
planted the sugar cane, which they brought from Sicily, and the vines which
they brought from Cyprus. Saw mills were likewise erected on it.

About the year 1432, Gonzalos was sent with two small vessels to the coast
of Africa on new discoveries. In 1434, Cape Boyada was doubled: in 1442,
the Portuguese had advanced as far as Rio-do-Ouro, under the tropic of
Cancer. On the return of the