PORTUGUESE EXPANSION AND THE REVIVAL OF PTOLEMY
There were obvious geographical and historical reasons why the kingdom
of Portugal should furnish the important series of incidents in the
expansion of geographical knowledge which now claims attention.
The Arab power in the Iberian peninsula had been broken, and the
Portuguese monarchy had established itself during the twelfth century.
The Arab mantle of the explorer descended upon Portuguese shoulders.
The small kingdom has a large extent of coastline; and not only is
communication with Europe by land through the passes at either end of
the Pyrenees comparatively difficult, but between those passes and
Portugal were Spanish states, with which Portuguese relations were by
no means amicable. Thus there was little opportunity for the commercial
expansion of Portugal except over-seas.
The first important figure in the history of this expansion is that of
Prince Henry, surnamed the Navigator (1394–1460), fifth son of King
John I. His objects were to extend Portuguese commercial interests
mainly in West Africa, and also, it would appear, to discover new
lands, if they were to be discovered, to the west of those Atlantic
islands which formed the limit of knowledge to the west from very early
times. Even the knowledge of the islands themselves was indefinite
enough; so that when, in or about 1415, Henry began sending his
seamen to the Canaries and later to the Madeira and the Azores, he
was inspiring, if not actual discovery, at any rate the acquisition
of largely new information. Between 1415 and 1431 colonization and
trade had already begun to be established in some of the islands;
and, though the Portuguese navigators did not forestall Columbus, it
is likely that they conceived the possibility of a westward route to
the Far East. Prince Henry’s residence from 1438 to 1460 was Sagres,
which consequently became a centre for geographical research, for
he gathered about him expert cartographers and instructors for his
navigators, whom he supplied with the best obtainable instruments,
maps, and information: he used not only European but also Arab sources.
With regard to the West African coast, he experienced some years of
comparative failure; but from 1444 explorations here were rapidly
extended, and a few of the leading navigators and explorers who worked
under Prince Henry’s direction and after his death may be mentioned.
In 1443 John Fernandez travelled inland in the district of Rio de
Oro, and collected valuable information about the resources, physical
conditions, and people of the south-west part of the Sahara. He made
further journeys in 1446–47. Diogo Gomez, in 1448, made his way up the
Gambia river. Alvise Cadamosto, a Venetian in Prince Henry’s service,
was working in 1455 south of the Senegal; and in 1456 he visited, and
probably actually discovered, the Cape Verde Islands. His accounts
of his voyages were full and valuable, and he also dealt with the
explorations of Pedro de Cintra, in 1461 or 1462, to Sierra Leone and
the Gold Coast. Gomez made a voyage to the Cape Verde Islands in 1462;
but he is most notable as chronicler of the life-work of Prince Henry.
King John II built on the prince’s foundations. In 1482 he sent out
Diogo Cão, who discovered the Congo and ascended it for a short
distance, and subsequently saw the coast of Angola as far as 13° 26´
S. at Cape Santa Maria. On a second voyage (1485–1486) he penetrated
still further south, to Cape Cross. He erected pillars at various
points on the coast--a practice followed by some of his successors;
and some of these monuments have been found and preserved. In a voyage
in 1486 or 1487–88 Bartolomeu Diaz extended the knowledge of the west
coast nearly five degrees beyond Cão’s furthest, reaching 26° 38´ S.
He was then driven south by high winds and storms, turned east, and
found no land; he therefore steered north again, and struck the coast
of what is now the Cape Province at Mossel Bay. Continuing eastward, he
reached the Great Fish River, and was able to realize that the coast
was now trending north-easterly, and that the southernmost point of
the continent had been turned; but his crew were surfeited with their
dangers, and insisted on returning. The important cape which he had
discovered he is generally stated to have named Cabo Tormentoso, the
Cape of Storms; and the story goes that King John, recognizing the
importance of the discovery to the future object of a sea-route to the
East, changed the name to the Cape of Good Hope. But there is good
reason to believe that the happier name was given by Diaz himself. It
had been one of the wishes of Prince Henry, and was one of the objects
of the voyage of Diaz, to establish communication with a Christian
king of whose powers rumours reached the west coast of Africa from
the interior, and who was known under the name of Prester John. In
1487 Pedro or Pero de Covilhão and Alphonso Payva were sent, partly
with the same object, by way of the Mediterranean. They visited Egypt,
and after many wanderings came to Aden, whence Covilhão proceeded to
Calicut and Goa in India, and, returning thence, travelled south along
the East African coast as far as Sofala. He then journeyed in the coast
lands of Arabia, and visited Mecca and Medina, and finally, entering
Africa, proceeded to the court of Prester John in Abyssinia, where he
was well treated, but from which he was never allowed to return home.
Payva, meanwhile, had travelled into Ethiopia, and had died there.
The journey to India by way of the Cape of Good Hope was completed
in due course in the last decade of the century; but earlier in that
same decade the New World had been discovered by Columbus, and the
era opened by these two tremendous incidents may be more fittingly
considered in the following chapter; while for the moment some
consideration may be given to the state of cartography and theory at
the time when Columbus was planning his voyage.
The works of Ptolemy can have been known to few in the original Greek
at this time, and for many centuries before. When, therefore, the
translation of his Geography into Latin, originally undertaken by
Emanuel Chrysoloras, a Byzantine scholar who settled in Italy, was
completed in 1410 by his pupil Jacobus Angelus, these two students
lit a beacon in the course of geographical study. The translation,
which is usually identified with the name of Angelus alone, was issued
under the title of Cosmography instead of Geography. It would appear
that Angelus, of whose life apart from this work little is known,
not only dealt with the text, but also did the maps into Latin. In a
short time there was no lack of copies of the work, and it was soon
found necessary to add to the maps at certain points where they failed
to represent knowledge which was by this time in possession of the
translators. Already about 1424 Claudius Clavus Swartha had constructed
in Italy a map which showed the north-westward extension of knowledge
as far as Greenland; the curious orderly curves by which the coastlines
are represented frankly acknowledge the draughtsman’s lack of detail.
About 1470 Nicolaus Germanus, often known erroneously as Donis,
produced a manuscript edition of Ptolemy, with maps magnificently
illuminated and on improved projections. He also added new maps, and
it has been said of the collection that, as far as concerns methods of
drawing, it is the prototype of all subsequent atlases (Nordenskjöld).
An edition, probably of 1472, if not later, though it is dated
earlier, reveals the use of a conical projection with meridians and
parallels drawn across the maps; and, as points of some interest in
comparison with modern maps, it may be added that the seas are green,
the mountains blue, and other parts of the land red and yellow. The
Florentine edition in verse, of about 1480, by Francesco Berlinghieri,
contained an important series of new printed maps, including Italy,
France, Spain, and Palestine.
Although the extension of knowledge to the north-west, as has been
mentioned, attracted considerable attention on the part of the editors
of Ptolemy, the recent Portuguese discoveries in West Africa did not,
apparently, do the same. In an edition, for instance, of 1486, made
at Ulm, a geographical description of the north-west lands, including
Greenland, was furnished, and there were quoted the latitude and
longitude of 183 places in northern Europe and Greenland; but there
was no evidence that the conception of the southern limit of the
habitable world by Ptolemy was understood to be now proved wholly
erroneous by the Portuguese discoveries.
On the other hand, the appreciation of Portuguese labours appeared
earlier, as was natural, in Portolano maps. That of Andrea Bianco
(1448) drew probably on a Portuguese original, showing the West African
coast as far as Cape Verde. On the world map of Fra Mauro, already
referred to, the Portuguese discoveries are mentioned in an inscription
of considerable length.
In connection with prevailing ideas as to what lands lay in the
Atlantic beyond the certain knowledge of men, it may be observed that
the conception of a continent or island of Atlantis was very old, and
there were other mythical lands which were also given places in distant
parts of the ocean. Portolano maps of the fourteenth and fifteenth
centuries show the island of Brazil lying to the west of Ireland, an
island named Mam to the south of Brazil, and, still further away in
the ocean, and to the south again, a large island in the form of a
parallelogram, which bore the name of Antillia, and appears as early as
1426.
The sphericity of the earth, as has been seen, was revived as a theory
by Bacon and Albertus; and to these inquirers may now be added the name
of Cardinal d’Ailly (d. 1422), whose work, entitled _Imago Mundi_, may
be mentioned because it is known to have been in the possession of
Columbus. His copy still exists.
A name closely identified with Columbus’s preconceived ideas as to
the voyage to the Indies by way of the western ocean, and his efforts
to obtain recognition for them, is that of Paolo del Pozzo Toscanelli
(1397–1482), a Florentine mathematician, astronomer, and cosmographer,
whose advice was asked by King Alphonso V. of Portugal as to the
probability of this western route. He sent the king a statement and
a chart in support of Columbus’s ideas. The chart is lost; but the
author describes it as showing the Indies opposite and to the west
of Ireland and Africa, together with the islands which were known to
lie off the coast of the Asiatic mainland, and certain known landing
places. A globe made in 1492 by Martin Behaim, of Nuremberg, is usually
cited as giving the best existing representation of the views as to the
extent of the Atlantic, and the route across it, at the moment when
Columbus began his first voyage. Behaim had lived in Portugal, and had
a high scientific reputation at court. He had probably visited the
more northerly parts of the west coast of Africa and also the Azores,
though he claimed to have a much more extensive first-hand knowledge,
as having accompanied Diogo Cão. It is doubtful if he did so; but if he
did, he made but little use of his opportunity. His representation of
the west coast of Africa is not accurate; and for the rest, although
he had the chance, and apparently an unusually favourable one, of
carrying the results of Portuguese research into Europe, he made poor
use of it. He was obsessed by Ptolemaic ideas; he showed in a modified
form the old south-eastward extension of Africa, with Madagascar and
Zanzibar as two great islands lying off it, Zanzibar being south of
Madagascar. He also modified, but still retained, the Ptolemaic idea of
the non-peninsular form of India and the exaggerated size of Ceylon.
He gave a gross representation of the Malay Peninsula, and in general
ignored Marco Polo’s results, and those of other Asiatic travellers.
His representation of Scandinavia was indifferent, and even that of
the Mediterranean was below the level of the Portolano maps. As regards
the width of the Atlantic Ocean between Europe and Asia, he appears to
have followed Toscanelli; and he showed the mythical island of Antillia
and also that of St. Brandon (the existence of which on maps was an
outcome of the fabled wanderings of a holy man of Ireland in the sixth
century) in mid-ocean between the Euro-African and the Asiatic coasts.
Such was the view of the ocean barrier which lay between Columbus and
the attainment of his ideal. It serves as a reminder, which, in view of
the results he obtained, is sometimes necessary, that that ideal was
the discovery, not of new lands, but of a new route to lands already
known.