coast. There was an ancient belief that ships could not enter tropic
seas because the intensely hot sun drew up all the water and left only
the slimy ooze of the bottom of the ocean. Cape Nun, of Morocco, was the
most southerly point of Africa yet reached; and about it there was a
discouraging saying,

"Who pass Cape Nun
Must turn again or else be gone."

Prince Henry, who was called the "Protector of Studies in Portugal," did
not believe that rhyme, and determined to show how foolish and untrue it
was. His first step was to establish an observatory and a school for
navigation at Cape St. Vincent, the most westerly point of Europe and
the most southwesterly point of Portugal. To this observatory the prince
invited the most learned astronomers, geographers, and instrument-makers
then living, that they might all work together with him; and from the
little fishing village of Sagres, close to his great observatory, he
sent out sailors who, according to an old writer, "were well taught in
all rules which sailors ought to know, and provided with the best
instruments for navigation."

These expeditions began fifty years before Columbus came to Lisbon. Most
of them sailed south; out there had always been legends of lands in the
west, so westward some of them sailed and found the Azores and the
Madeira Islands. These last had been known to English navigators more
than a century before, but as England sent no people to occupy and claim
them, Portugal took possession of them.

How the ownership of all newly-found portions of the globe came to be
determined is worth looking into. Ever since the time of the Crusades it